Evaluation of chemopreventive and chemotherapeutic effect of Artemisia vulgaris extract against diethylnitrosamine induced hepatocellular carcinogenesis in Balb C mice / Avaliação dos efeitos quimiopreventivo e quimioterápico do extrato de Artemisia vulgaris contra carcinogênese hepatocelular induzida por dietilnitrosamina em camundongos Balb C

The main objective of current study was to investigate the chemopreventive and chemotherapeutic activity of Artemisia vulgaris extract on diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Diethylnitrosoamine (DEN: 0.9%) was prepared to induce hepatocarcinoma in Balb C mice. The extract Artemisia vulgaris (AV) was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received only plant extract (AV: 150 mg/kg (Body weight) once in a week, while group 4 (N=7) was given in combination of diethylnitrosoamine (3.5 l/mg) and plant extract (AV: 150 mg/kg (body weight). After eight weeks of DEN administration, mice of group 2 were divided into two subgroups containing seven mice each; subgroup 1 was sacrificed while subgroup 2 was treated with plant extract only (150 mg/kg (body weight)) once in a week for eight consecutive weeks. The DEN injected mice significant decline in levels of albumin with concomitant significant elevations such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alpha feto protein, gamma glutamyl transferase, 5 nucleotidase, glucose-6-phosphate dehydrogenase and bilirubin. The administration of A. vulgaris significantly decreased the DEN induced hepatotoxicity. Present study revealed the potential anti-cancerous nature of Artemisia vulgaris, both in case of chemopreventive and post-treatment of A. vulgaris. Further studies are needed to explore the mechanism of prevention and therapy.

O objetivo principal do presente estudo foi investigar as atividades quimiopreventiva e quimioterápica do extrato de Artemisia vulgaris em hepatocarcinogênese induzida por dietilnitrosoamina (DEN) em camundongos Balb C. Dietilnitrosoamina (DEN: 0,9%) foi preparada para induzir hepatocarcinoma em camundongos da linhagem Balb C. O extrato de A. vulgaris (AV) foi preparado pela técnica de maceração. Os camundongos foram classificados em quatro grupos conforme os seguintes: grupo 1, grupo controle (N=7) recebeu solução salina (3,5 µl/mg); grupo 2 (N=14) recebeu dietilnitrosoamina (3,5 µl/mg) por via intraperitoneal uma vez por semana durante oito semanas consecutivas; grupo 3 (N=7) recebeu apenas o extrato vegetal (AV: 150 mg/kg (peso corporal) uma vez por semana; enquanto no grupo 4 (N=7) foi administrado uma combinação de dietilnitrosoamina (3,5 l/mg) com extrato vegetal (AV: 150 mg/kg (peso corporal). Após oito semanas de administração de DEN, os camundongos do grupo 2 foram divididos em dois subgrupos, contendo sete camundongos cada um; no subgrupo 1, os animais foram sacrificados, enquanto no subgrupo 2, os animais foram tratados apenas com extrato vegetal (150 mg/kg (peso corporal)) uma vez por semana durante oito semanas consecutivas. Os camundongos nos quais foram injetados DEN apresentaram declínio significativo nos níveis de albumina, mas elevações significativas concomitantes de: aspartato aminotransferase, alanina aminotransferase, lactato desidrogenase, alfa-fetoproteína, gama-glutamiltransferase, 5 nucleotidase, glicose-6-fosfato desidrogenase e bilirrubina. A administração de A. vulgaris diminuiu significativamente a hepatotoxicidade induzida pelo DEN. O presente estudo apresentou a potencialidade anticancerosa da A. vulgaris, tanto nos casos de quimioprevenção quanto no pós-tratamento da A. vulgaris. Mais estudos são necessários para explorar o mecanismo de prevenção e a terapia.

Evaluation of chemopreventive and chemotherapeutic effect of Artemisia vulgaris extract against diethylnitrosamine induced hepatocellular carcinogenesis in Balb C mice / Avaliação dos efeitos quimiopreventivo e quimioterápico do extrato de Artemisia vulgaris contra carcinogênese hepatocelular induzida por dietilnitrosamina em camundongos Balb C

The main objective of current study was to investigate the chemopreventive and chemotherapeutic activity of Artemisia vulgaris extract on diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Diethylnitrosoamine (DEN: 0.9%) was prepared to induce hepatocarcinoma in Balb C mice. The extract Artemisia vulgaris (AV) was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received only plant extract (AV: 150 mg/kg (Body weight) once in a week, while group 4 (N=7) was given in combination of diethylnitrosoamine (3.5 l/mg) and plant extract (AV: 150 mg/kg (body weight). After eight weeks of DEN administration, mice of group 2 were divided into two subgroups containing seven mice each; subgroup 1 was sacrificed while subgroup 2 was treated with plant extract only (150 mg/kg (body weight)) once in a week for eight consecutive weeks. The DEN injected mice significant decline in levels of albumin with concomitant significant elevations such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alpha feto protein, gamma glutamyl transferase, 5 nucleotidase, glucose-6-phosphate dehydrogenase and bilirubin. The administration of A. vulgaris significantly decreased the DEN induced hepatotoxicity. Present study revealed the potential anti-cancerous nature of Artemisia vulgaris, both in case of chemopreventive and post-treatment of A. vulgaris. Further studies are needed to explore the mechanism of prevention and therapy.(AU)

O objetivo principal do presente estudo foi investigar as atividades quimiopreventiva e quimioterápica do extrato de Artemisia vulgaris em hepatocarcinogênese induzida por dietilnitrosoamina (DEN) em camundongos Balb C. Dietilnitrosoamina (DEN: 0,9%) foi preparada para induzir hepatocarcinoma em camundongos da linhagem Balb C. O extrato de A. vulgaris (AV) foi preparado pela técnica de maceração. Os camundongos foram classificados em quatro grupos conforme os seguintes: grupo 1, grupo controle (N=7) recebeu solução salina (3,5 µl/mg); grupo 2 (N=14) recebeu dietilnitrosoamina (3,5 µl/mg) por via intraperitoneal uma vez por semana durante oito semanas consecutivas; grupo 3 (N=7) recebeu apenas o extrato vegetal (AV: 150 mg/kg (peso corporal) uma vez por semana; enquanto no grupo 4 (N=7) foi administrado uma combinação de dietilnitrosoamina (3,5 l/mg) com extrato vegetal (AV: 150 mg/kg (peso corporal). Após oito semanas de administração de DEN, os camundongos do grupo 2 foram divididos em dois subgrupos, contendo sete camundongos cada um; no subgrupo 1, os animais foram sacrificados, enquanto no subgrupo 2, os animais foram tratados apenas com extrato vegetal (150 mg/kg (peso corporal)) uma vez por semana durante oito semanas consecutivas. Os camundongos nos quais foram injetados DEN apresentaram declínio significativo nos níveis de albumina, mas elevações significativas concomitantes de: aspartato aminotransferase, alanina aminotransferase, lactato desidrogenase, alfa-fetoproteína, gama-glutamiltransferase, 5 nucleotidase, glicose-6-fosfato desidrogenase e bilirrubina. A administração de A. vulgaris diminuiu significativamente a hepatotoxicidade induzida pelo DEN. O presente estudo apresentou a potencialidade anticancerosa da A. vulgaris, tanto nos casos de quimioprevenção quanto no pós-tratamento da A. vulgaris. Mais estudos são necessários para explorar o mecanismo de prevenção e a terapia.(AU)

In vivo induction of hepatocellular carcinoma by diethylnitrosoamine and pharmacological intervention in Balb C mice using Bergenia ciliata extracts / Indução in vivo de carcinoma hepatocelular por dietilnitrosoamina e intervenção farmacológica em camundongos balb c usando extratos de Bergenia ciliata

Background Hepatocellular carcinoma is the most frequent primary malignancy of liver and accounts for as many as one million deaths worldwide in a year. Objectives The aim of the present study was to evaluate the anti-cancerous efficiency of Bergenia ciliata rhizome against diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Methods One percent diethylnitrosoamine was prepared by using 99 ml of normal saline NaCl (0.9 percent) solution to which was added 1 ml of concentrated diethylnitrosoamine (DEN) solution (0.01 g/l). Extract of Bergenia ciliata was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received plant extract (150 mg/kg (Body weight)) once in a week, while group 4 (N=7) was given combination of diethylnitrosoamine (3.5 l/mg) and plant extract (150 mg/kg (Body weight)). After eight weeks of DEN induction group 2 mice were divided into two subgroups containing seven mice each, subgroup 1 was sacrificed while subgroup 2 was treated with plant extract (150 mg/kg (Body weight)) once in a week for eight consecutive weeks. Results The model of DEN injected hepatocellular carcinomic (HCC) mice elicited significant decline in levels of albumin with concomitant significant elevations in tumor markers aspartate aminotransferase, alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alpha feto protein (AFP), gamma glutamyl transferase (Y-GT), 5 nucleotidase (5NT), glucose-6-phosphate dehydrogenase (G6PDH) and bilirubin. The intraperitoneal administration of B. ciliata as a protective agent, produced significant increase in albumin levels with significant decrease in the levels of tumor markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alpha feto protein (AFP), gamma glutamyl transferase (Y-GT), 5 nucleotidase (5NT), glucose-6-phosphate dehydrogenase (G6PDH) and bilirubin. Conclusion Bergenia ciliata has potent antioxidant activity, radical scavenging capacity and anticancerous properties. Bergenia ciliata extracts may provide a basis for development of anti-cancerous drug.(AU)

Antecedentes O carcinoma hepatocelular é a neoplasia primária mais frequente do fígado e é responsável por até um milhão de mortes em todo o mundo em um ano. Objetivos O objetivo do presente estudo foi avaliar a eficiência anticancerígena do rizoma de Bergenia ciliata contra a hepatocarcinogênese induzida por dietilnitrosoamina em camundongos balb c. Métodos Um por cento de dietilnitrosoamina foi preparado usando 99 ml de solução salina normal (0,9 por cento) à qual foi adicionado 1 ml de solução concentrada de dietilnitrosoamina (DEN) (0,01 g / l). O extrato de Bergenia ciliata foi preparado pela técnica de maceração. Os ratos foram classificados em quatro grupos: Grupo 1 grupo controle (N = 7) recebeu solução salina (3,5 mL / mg), grupo 2 (N = 14) recebeu dietilnitrosoamina (3,5 mL / mg) por via intraperitoneal uma vez por semana para oito semanas consecutivas, o grupo 3 (N = 7) recebeu extrato vegetal (150 mg / kg (peso corporal)) uma vez por semana, enquanto o grupo 4 (N = 7) recebeu combinação de dietilnitrosoamina (3,5 l / mg) e extrato (150 mg / kg (peso corporal). Após oito semanas do grupo de indução DEN 2 ratos foram divididos em dois subgrupos contendo sete ratos cada, subgrupo 1 foi sacrificado enquanto subgrupo 2 foi tratado com extrato vegetal (150 mg / kg)) uma vez por semana durante oito semanas consecutivas. Resultados O modelo de camundongos hepatocelulares carcinômicos (CHC) injetados com DEN provocou declínio significativo nos níveis de albumina com elevações significativas concomitantes nos marcadores tumorais: aspartato aminotransferase, alanina aminotransferase (ALT), lactato desidrogenase (LDH), proteína alfa feto (AFP), gama glutamiltransferase (Y-GT), 5 nucleotidase (5NT), glicose-6-fosfato ehidrogenase (G6PDH) e bilirrubina. A administração intraperitoneal de B. ciliata como agente protetor produziu um aumento significativo nos níveis de albumina com uma diminuição significativa nos níveis dos marcadores tumorais: aspartato aminotransferase, alanina aminotransferase (ALT), lactato desidrogenase (LDH), proteína alfa feto (AFP), gama glutamiltransferase (Y-GT), 5 nucleotidase (5NT), glicose-6-fosfato desidrogenase (G6PDH) e bilirrubina. Conclusão Bergenia ciliata possui atividade antioxidante potente, capacidade de eliminação de radicais livres e propriedades anticancerígenas. Extratos de Bergenia ciliata podem fornecer uma base para o desenvolvimento de drogas anti-cancerígenas.(AU)

In vivo induction of hepatocellular carcinoma by diethylnitrosoamine and pharmacological intervention in Balb C mice using Bergenia ciliata extracts

Abstract Background Hepatocellular carcinoma is the most frequent primary malignancy of liver and accounts for as many as one million deaths worldwide in a year. Objectives The aim of the present study was to evaluate the anti-cancerous efficiency of Bergenia ciliata rhizome against diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Methods One percent diethylnitrosoamine was prepared by using 99 ml of normal saline NaCl (0.9 percent) solution to which was added 1 ml of concentrated diethylnitrosoamine (DEN) solution (0.01 g/l). Extract of Bergenia ciliata was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received plant extract (150 mg/kg (Body weight)) once in a week, while group 4 (N=7) was given combination of diethylnitrosoamine (3.5 l/mg) and plant extract (150 mg/kg (Body weight)). After eight weeks of DEN induction group 2 mice were divided into two subgroups containing seven mice each, subgroup 1 was sacrificed while subgroup 2 was treated with plant extract (150 mg/kg (Body weight)) once in a week for eight consecutive weeks. Results The model of DEN injected hepatocellular carcinomic (HCC) mice elicited significant decline in levels of albumin with concomitant significant elevations in tumor markers aspartate aminotransferase, alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alpha feto protein (AFP), gamma glutamyl transferase (Y-GT), 5 nucleotidase (5NT), glucose-6-phosphate dehydrogenase (G6PDH) and bilirubin. The intraperitoneal administration of B. ciliata as a protective agent, produced significant increase in albumin levels with significant decrease in the levels of tumor markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alpha feto protein (AFP), gamma glutamyl transferase (Y-GT), 5 nucleotidase (5NT), glucose-6-phosphate dehydrogenase (G6PDH) and bilirubin. Conclusion Bergenia ciliata has potent antioxidant activity, radical scavenging capacity and anticancerous properties. Bergenia ciliata extracts may provide a basis for development of anti-cancerous drug.

Resumo Antecedentes O carcinoma hepatocelular é a neoplasia primária mais frequente do fígado e é responsável por até um milhão de mortes em todo o mundo em um ano. Objetivos O objetivo do presente estudo foi avaliar a eficiência anticancerígena do rizoma de Bergenia ciliata contra a hepatocarcinogênese induzida por dietilnitrosoamina em camundongos balb c. Métodos Um por cento de dietilnitrosoamina foi preparado usando 99 ml de solução salina normal (0,9 por cento) à qual foi adicionado 1 ml de solução concentrada de dietilnitrosoamina (DEN) (0,01 g / l). O extrato de Bergenia ciliata foi preparado pela técnica de maceração. Os ratos foram classificados em quatro grupos: Grupo 1 grupo controle (N = 7) recebeu solução salina (3,5 mL / mg), grupo 2 (N = 14) recebeu dietilnitrosoamina (3,5 mL / mg) por via intraperitoneal uma vez por semana para oito semanas consecutivas, o grupo 3 (N = 7) recebeu extrato vegetal (150 mg / kg (peso corporal)) uma vez por semana, enquanto o grupo 4 (N = 7) recebeu combinação de dietilnitrosoamina (3,5 l / mg) e extrato (150 mg / kg (peso corporal). Após oito semanas do grupo de indução DEN 2 ratos foram divididos em dois subgrupos contendo sete ratos cada, subgrupo 1 foi sacrificado enquanto subgrupo 2 foi tratado com extrato vegetal (150 mg / kg)) uma vez por semana durante oito semanas consecutivas. Resultados O modelo de camundongos hepatocelulares carcinômicos (CHC) injetados com DEN provocou declínio significativo nos níveis de albumina com elevações significativas concomitantes nos marcadores tumorais: aspartato aminotransferase, alanina aminotransferase (ALT), lactato desidrogenase (LDH), proteína alfa feto (AFP), gama glutamiltransferase (Y-GT), 5 nucleotidase (5NT), glicose-6-fosfato ehidrogenase (G6PDH) e bilirrubina. A administração intraperitoneal de B. ciliata como agente protetor produziu um aumento significativo nos níveis de albumina com uma diminuição significativa nos níveis dos marcadores tumorais: aspartato aminotransferase, alanina aminotransferase (ALT), lactato desidrogenase (LDH), proteína alfa feto (AFP), gama glutamiltransferase (Y-GT), 5 nucleotidase (5NT), glicose-6-fosfato desidrogenase (G6PDH) e bilirrubina. Conclusão Bergenia ciliata possui atividade antioxidante potente, capacidade de eliminação de radicais livres e propriedades anticancerígenas. Extratos de Bergenia ciliata podem fornecer uma base para o desenvolvimento de drogas anti-cancerígenas.

Evaluation of chemopreventive and chemotherapeutic effect of Artemisia vulgaris extract against diethylnitrosamine induced hepatocellular carcinogenesis in Balb C mice

Abstract The main objective of current study was to investigate the chemopreventive and chemotherapeutic activity of Artemisia vulgaris extract on diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Diethylnitrosoamine (DEN: 0.9%) was prepared to induce hepatocarcinoma in Balb C mice. The extract Artemisia vulgaris (AV) was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received only plant extract (AV: 150 mg/kg (Body weight) once in a week, while group 4 (N=7) was given in combination of diethylnitrosoamine (3.5 l/mg) and plant extract (AV: 150 mg/kg (body weight). After eight weeks of DEN administration, mice of group 2 were divided into two subgroups containing seven mice each; subgroup 1 was sacrificed while subgroup 2 was treated with plant extract only (150 mg/kg (body weight)) once in a week for eight consecutive weeks. The DEN injected mice significant decline in levels of albumin with concomitant significant elevations such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alpha feto protein, gamma glutamyl transferase, 5 nucleotidase, glucose-6-phosphate dehydrogenase and bilirubin. The administration of A. vulgaris significantly decreased the DEN induced hepatotoxicity. Present study revealed the potential anti-cancerous nature of Artemisia vulgaris, both in case of chemopreventive and post-treatment of A. vulgaris. Further studies are needed to explore the mechanism of prevention and therapy.

Resumo O objetivo principal do presente estudo foi investigar as atividades quimiopreventiva e quimioterápica do extrato de Artemisia vulgaris em hepatocarcinogênese induzida por dietilnitrosoamina (DEN) em camundongos Balb C. Dietilnitrosoamina (DEN: 0,9%) foi preparada para induzir hepatocarcinoma em camundongos da linhagem Balb C. O extrato de A. vulgaris (AV) foi preparado pela técnica de maceração. Os camundongos foram classificados em quatro grupos conforme os seguintes: grupo 1, grupo controle (N=7) recebeu solução salina (3,5 µl/mg); grupo 2 (N=14) recebeu dietilnitrosoamina (3,5 µl/mg) por via intraperitoneal uma vez por semana durante oito semanas consecutivas; grupo 3 (N=7) recebeu apenas o extrato vegetal (AV: 150 mg/kg (peso corporal) uma vez por semana; enquanto no grupo 4 (N=7) foi administrado uma combinação de dietilnitrosoamina (3,5 l/mg) com extrato vegetal (AV: 150 mg/kg (peso corporal). Após oito semanas de administração de DEN, os camundongos do grupo 2 foram divididos em dois subgrupos, contendo sete camundongos cada um; no subgrupo 1, os animais foram sacrificados, enquanto no subgrupo 2, os animais foram tratados apenas com extrato vegetal (150 mg/kg (peso corporal)) uma vez por semana durante oito semanas consecutivas. Os camundongos nos quais foram injetados DEN apresentaram declínio significativo nos níveis de albumina, mas elevações significativas concomitantes de: aspartato aminotransferase, alanina aminotransferase, lactato desidrogenase, alfa-fetoproteína, gama-glutamiltransferase, 5 nucleotidase, glicose-6-fosfato desidrogenase e bilirrubina. A administração de A. vulgaris diminuiu significativamente a hepatotoxicidade induzida pelo DEN. O presente estudo apresentou a potencialidade anticancerosa da A. vulgaris, tanto nos casos de quimioprevenção quanto no pós-tratamento da A. vulgaris. Mais estudos são necessários para explorar o mecanismo de prevenção e a terapia.

Effect of phospholipase A2 inhibitors during infection caused by Leishmania (Leishmania) amazonensis

Background: Lipid metabolites play an important role in parasite differentiation and virulence. Studies have revealed that Leishmania sp. uses prostaglandins to evade innate barriers, thus enabling the parasites to survive inside immune cells. Despite the role of the enzyme Phospholipase A2 (PLA2) in prostaglandins production, few studies have investigated the role of parasite PLA2 during the interaction between L. (L.) amazonensis and the host (in vitro and in vivo) immune cells. Methods: In the present work, the leishmanicidal effect of PLA2 inhibitors, methyl arachidonyl fluorophosphonate (MAFP), bromoenol lactone (BEL) and aristolochic acid (AA) were investigated in vitro (promastigote and intracellular amastigote forms of L. (L.) amazonensis) and during in vivo infection using BALB/c mice. Results: The aforementioned inhibitors were deleterious to promastigote and amastigote forms of the L. (L.) amazonensis and were non-toxic to peritoneal macrophages from BALB/c mice. L. (L.) amazonensis-infected BALB/c mice treated with the inhibitor BEL presented decreased lesion size and skin parasitism; however, BEL treatment induced hepatotoxicity in BALB/c mice. Conclusions: Results presented herein suggested that PLA2 inhibitors altered L. (L.) amazonensis viability. In spite of liver toxicity, treatment with BEL was the most selective compound in vitro, as well in vivo, resulting in lower skin parasitism in the infected mice. These findings corroborate the role of PLA2 in parasite virulence and maintenance in vertebrate hosts, and suggest that molecules structurally related to BEL should be considered when planning compounds against Leishmania sp.(AU)

Effect of phospholipase A2 inhibitors during infection caused by Leishmania (Leishmania) amazonensis

Background: Lipid metabolites play an important role in parasite differentiation and virulence. Studies have revealed that Leishmania sp. uses prostaglandins to evade innate barriers, thus enabling the parasites to survive inside immune cells. Despite the role of the enzyme Phospholipase A2 (PLA2) in prostaglandins production, few studies have investigated the role of parasite PLA2 during the interaction between L. (L.) amazonensis and the host (in vitro and in vivo) immune cells. Methods: In the present work, the leishmanicidal effect of PLA2 inhibitors, methyl arachidonyl fluorophosphonate (MAFP), bromoenol lactone (BEL) and aristolochic acid (AA) were investigated in vitro (promastigote and intracellular amastigote forms of L. (L.) amazonensis) and during in vivo infection using BALB/c mice. Results: The aforementioned inhibitors were deleterious to promastigote and amastigote forms of the L. (L.) amazonensis and were non-toxic to peritoneal macrophages from BALB/c mice. L. (L.) amazonensis-infected BALB/c mice treated with the inhibitor BEL presented decreased lesion size and skin parasitism; however, BEL treatment induced hepatotoxicity in BALB/c mice. Conclusions: Results presented herein suggested that PLA2 inhibitors altered L. (L.) amazonensis viability. In spite of liver toxicity, treatment with BEL was the most selective compound in vitro, as well in vivo, resulting in lower skin parasitism in the infected mice. These findings corroborate the role of PLA2 in parasite virulence and maintenance in vertebrate hosts, and suggest that molecules structurally related to BEL should be considered when planning compounds against Leishmania sp.

Evaluation of chemopreventive and chemotherapeutic effect of Artemisia vulgaris extract against diethylnitrosamine induced hepatocellular carcinogenesis in Balb C mice

Abstract The main objective of current study was to investigate the chemopreventive and chemotherapeutic activity of Artemisia vulgaris extract on diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Diethylnitrosoamine (DEN: 0.9%) was prepared to induce hepatocarcinoma in Balb C mice. The extract Artemisia vulgaris (AV) was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received only plant extract (AV: 150 mg/kg (Body weight) once in a week, while group 4 (N=7) was given in combination of diethylnitrosoamine (3.5 l/mg) and plant extract (AV: 150 mg/kg (body weight). After eight weeks of DEN administration, mice of group 2 were divided into two subgroups containing seven mice each; subgroup 1 was sacrificed while subgroup 2 was treated with plant extract only (150 mg/kg (body weight)) once in a week for eight consecutive weeks. The DEN injected mice significant decline in levels of albumin with concomitant significant elevations such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alpha feto protein, gamma glutamyl transferase, 5 nucleotidase, glucose-6-phosphate dehydrogenase and bilirubin. The administration of A. vulgaris significantly decreased the DEN induced hepatotoxicity. Present study revealed the potential anti-cancerous nature of Artemisia vulgaris, both in case of chemopreventive and post-treatment of A. vulgaris. Further studies are needed to explore the mechanism of prevention and therapy.

Resumo O objetivo principal do presente estudo foi investigar as atividades quimiopreventiva e quimioterápica do extrato de Artemisia vulgaris em hepatocarcinogênese induzida por dietilnitrosoamina (DEN) em camundongos Balb C. Dietilnitrosoamina (DEN: 0,9%) foi preparada para induzir hepatocarcinoma em camundongos da linhagem Balb C. O extrato de A. vulgaris (AV) foi preparado pela técnica de maceração. Os camundongos foram classificados em quatro grupos conforme os seguintes: grupo 1, grupo controle (N=7) recebeu solução salina (3,5 µl/mg); grupo 2 (N=14) recebeu dietilnitrosoamina (3,5 µl/mg) por via intraperitoneal uma vez por semana durante oito semanas consecutivas; grupo 3 (N=7) recebeu apenas o extrato vegetal (AV: 150 mg/kg (peso corporal) uma vez por semana; enquanto no grupo 4 (N=7) foi administrado uma combinação de dietilnitrosoamina (3,5 l/mg) com extrato vegetal (AV: 150 mg/kg (peso corporal). Após oito semanas de administração de DEN, os camundongos do grupo 2 foram divididos em dois subgrupos, contendo sete camundongos cada um; no subgrupo 1, os animais foram sacrificados, enquanto no subgrupo 2, os animais foram tratados apenas com extrato vegetal (150 mg/kg (peso corporal)) uma vez por semana durante oito semanas consecutivas. Os camundongos nos quais foram injetados DEN apresentaram declínio significativo nos níveis de albumina, mas elevações significativas concomitantes de: aspartato aminotransferase, alanina aminotransferase, lactato desidrogenase, alfa-fetoproteína, gama-glutamiltransferase, 5 nucleotidase, glicose-6-fosfato desidrogenase e bilirrubina. A administração de A. vulgaris diminuiu significativamente a hepatotoxicidade induzida pelo DEN. O presente estudo apresentou a potencialidade anticancerosa da A. vulgaris, tanto nos casos de quimioprevenção quanto no pós-tratamento da A. vulgaris. Mais estudos são necessários para explorar o mecanismo de prevenção e a terapia.

In vivo induction of hepatocellular carcinoma by diethylnitrosoamine and pharmacological intervention in Balb C mice using Bergenia ciliata extracts

Abstract Background Hepatocellular carcinoma is the most frequent primary malignancy of liver and accounts for as many as one million deaths worldwide in a year. Objectives The aim of the present study was to evaluate the anti-cancerous efficiency of Bergenia ciliata rhizome against diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Methods One percent diethylnitrosoamine was prepared by using 99 ml of normal saline NaCl (0.9 percent) solution to which was added 1 ml of concentrated diethylnitrosoamine (DEN) solution (0.01 g/l). Extract of Bergenia ciliata was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 l/mg), group 2 (N=14) received diethylnitrosoamine (3.5 l/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received plant extract (150 mg/kg (Body weight)) once in a week, while group 4 (N=7) was given combination of diethylnitrosoamine (3.5 l/mg) and plant extract (150 mg/kg (Body weight)). After eight weeks of DEN induction group 2 mice were divided into two subgroups containing seven mice each, subgroup 1 was sacrificed while subgroup 2 was treated with plant extract (150 mg/kg (Body weight)) once in a week for eight consecutive weeks. Results The model of DEN injected hepatocellular carcinomic (HCC) mice elicited significant decline in levels of albumin with concomitant significant elevations in tumor markers aspartate aminotransferase, alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alpha feto protein (AFP), gamma glutamyl transferase (Y-GT), 5 nucleotidase (5NT), glucose-6-phosphate dehydrogenase (G6PDH) and bilirubin. The intraperitoneal administration of B. ciliata as a protective agent, produced significant increase in albumin levels with significant decrease in the levels of tumor markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alpha feto protein (AFP), gamma glutamyl transferase (Y-GT), 5 nucleotidase (5NT), glucose-6-phosphate dehydrogenase (G6PDH) and bilirubin. Conclusion Bergenia ciliata has potent antioxidant activity, radical scavenging capacity and anticancerous properties. Bergenia ciliata extracts may provide a basis for development of anti-cancerous drug.

Resumo Antecedentes O carcinoma hepatocelular é a neoplasia primária mais frequente do fígado e é responsável por até um milhão de mortes em todo o mundo em um ano. Objetivos O objetivo do presente estudo foi avaliar a eficiência anticancerígena do rizoma de Bergenia ciliata contra a hepatocarcinogênese induzida por dietilnitrosoamina em camundongos balb c. Métodos Um por cento de dietilnitrosoamina foi preparado usando 99 ml de solução salina normal (0,9 por cento) à qual foi adicionado 1 ml de solução concentrada de dietilnitrosoamina (DEN) (0,01 g / l). O extrato de Bergenia ciliata foi preparado pela técnica de maceração. Os ratos foram classificados em quatro grupos: Grupo 1 grupo controle (N = 7) recebeu solução salina (3,5 mL / mg), grupo 2 (N = 14) recebeu dietilnitrosoamina (3,5 mL / mg) por via intraperitoneal uma vez por semana para oito semanas consecutivas, o grupo 3 (N = 7) recebeu extrato vegetal (150 mg / kg (peso corporal)) uma vez por semana, enquanto o grupo 4 (N = 7) recebeu combinação de dietilnitrosoamina (3,5 l / mg) e extrato (150 mg / kg (peso corporal). Após oito semanas do grupo de indução DEN 2 ratos foram divididos em dois subgrupos contendo sete ratos cada, subgrupo 1 foi sacrificado enquanto subgrupo 2 foi tratado com extrato vegetal (150 mg / kg)) uma vez por semana durante oito semanas consecutivas. Resultados O modelo de camundongos hepatocelulares carcinômicos (CHC) injetados com DEN provocou declínio significativo nos níveis de albumina com elevações significativas concomitantes nos marcadores tumorais: aspartato aminotransferase, alanina aminotransferase (ALT), lactato desidrogenase (LDH), proteína alfa feto (AFP), gama glutamiltransferase (Y-GT), 5 nucleotidase (5NT), glicose-6-fosfato ehidrogenase (G6PDH) e bilirrubina. A administração intraperitoneal de B. ciliata como agente protetor produziu um aumento significativo nos níveis de albumina com uma diminuição significativa nos níveis dos marcadores tumorais: aspartato aminotransferase, alanina aminotransferase (ALT), lactato desidrogenase (LDH), proteína alfa feto (AFP), gama glutamiltransferase (Y-GT), 5 nucleotidase (5NT), glicose-6-fosfato desidrogenase (G6PDH) e bilirrubina. Conclusão Bergenia ciliata possui atividade antioxidante potente, capacidade de eliminação de radicais livres e propriedades anticancerígenas. Extratos de Bergenia ciliata podem fornecer uma base para o desenvolvimento de drogas anti-cancerígenas.

Vertical transmission of Toxocara canis in successive generations of mice

Visceral toxocariasis is a neglected zoonosis caused by Toxocara canis larvae in unusual hosts. In dogs, the definitive host, the infection occurs mainly through transplacental and transcolostral transmission. Studies on experimental models have shown that vertical transmission may result from acute infections. Considering that toxocariasis is characterized as a chronic infection, with possible reactivation of larvae present in the brain, this study evaluated the presence of larvae in the brain of female BALB/c mice and their offspring with chronic infection during three successive pregnancies. ELISA-TES was used to evaluate the antibody levels. T. canis larvae were detected in the brain tissue of the mice during the three successive generations evaluated. The offspring's IgG level gradually decreased, and mean absorbance (ABS) above the cutoff point (0.070) was observed only at 30 (0.229) and 50 (0.096) days of age, while IgM was not detected. The infections in the offspring confirmed that vertical transmission of T. canis larvae occurred during chronic toxocariasis in three successive generations of mice.

A toxocaríase visceral é uma zoonose negligenciada causada por larvas de Toxocara canis em hospedeiros não usuais. Em cães, os hospedeiros definitivos, a infecção ocorre normalmente por transmissão transplacentária e através do colostro. Estudos com modelos experimentais têm demonstrado a ocorrência de transmissão vertical durante a infecção aguda. Considerando que a toxocaríase é caracterizada como uma infecção crônica, com uma possível reativação das larvas presentes no cérebro, este estudo avaliou a presença de larvas no cérebro de camundongos Balb/C fêmeas e suas proles com infecção crônica durante três gestações sucessivas. Para avaliar os níveis de anticorpos foi utilizado ELISA-TES. Larvas de T. canis foram detectadas no encéfalo dos animais durante as três gerações sucessivas avaliadas. O nível de IgG das proles foi diminuindo gradualmente e as médias de absorbâncias (ABS) acima do ponto de corte (0,070) foram evidenciadas somente aos 30 (0,229) e 50 dias (0,096) de vida, enquanto que não foi detectada IgM. Infecções das proles confirmam a transmissão vertical de larvas de T. canis durante a toxocaríase crônica em três gerações sucessivas de camundongos.

Comparative pathologic and stereologic study of respiratory system in mice following administration of 3-methyl indole dissolved in propylene glycol and cremophor EL and LD50 determination

Background: 3-Methyl indole (Skatole, 3-MI) is produced by microfloral fermentation of tryptophan in rumen and production of that has relation with the onset of respiratory problems in cattle. The aim of this study was to compare complications of 3-MI dissolved in two solvents, Cremophor and Propylene Glycol on BALB/c mice by histopathologic and stereologic studies. Materials, Methods & Results: Female Balb/C mice 56 days of age (23 - 27 g) were divided into 13 groups of eight and had access to food and water ad libitum. Mice were housed in plastic cages (4 per cage) with wire bar lids on bedding of sawdust in an air-conditioned room with 12 h light: dark cycles. After a 7-day acclimation period, for 5 groups, Mice were injected with 400, 500, 600, 700 and 800 mg/kg from solution of 3-MI in propylene glycol and similarly for 5 other groups with Cremophor. As well as 2 groups were injected with Propylene glycol and Cremophor with the dosage that is necessary for solving the highest dose of 3-MI. One group received normal saline with the volume equal with Cremophor (drug vehicle) group. Briefly, 125 mg of 3-MI was dissolved per mL of sterile filtered Propylene glycol and 30 mg of 3-MI was dissolved per mL of sterile filtered Cremophor. Once injected intra peritoneally, mice were monitored 3-4 h for external reaction signs from the injection. LD50 was determined 610.16 mg/kg 3-Methylindole and 687.5 mg/kg 3-Methylindole dissolved in Propylene glycol and Cremophor respectively with linear regression. Increase in respiration rate, tachypnea and shallow respiration was observed in clinical examination. In necropsy, alveolar and bronchial hyperemia was significant in lungs. Some superficial wounds were observed in upper respiratory airways. Trachea and Hungarian airways were severely hyperemic. There were some debriss in airways canals. We couldnt find any lesion in other organs. Histopathology showed noticeable alveolar edema and emphysema, type I pneumocytes necrosis, Slight endothelial lesions, rare degeneration of type II pneumocytes and raised nutrophil infiltration around vessels were observed in higher dosages of both groups. Moderate interstitial edema, hyperemia and increase of alveolar macrophages were observed too. Increase of lymphocytes was noticed after the dose 600 mg/kg moderately on a dose dependent manner. There was a Hyaline membrane in the wall of air sacs. Endothelial capillary damage in Cremophor dissolved 3-MI groups were slightly lower. Although damage to the vessels was not that much progressed in both groups. Stereologic study of type II pneumocytes showed a significant increase in the percentage of them in alveoli of treatment groups in a dose dependent manner compare to control and drug vehicle groups. At the highest dose (800 mg/kg) the group with Propylene glycol as solvent had significant difference with Cremophor dissolved 3-Methyl indole group and epithelialization was more severe in that. Bronchiole injuries raised in a dose dependent manner in both treatment groups. Discussion: The results of this research indicate that intraperitoneal infusion of 3-MI dissolved in Propylene glycol and Cremophor cause noticeable changes in the respiratory systems of mice. Effects of 3-MI in Propylene glycol is more severe than 3-MI dissolved in Cremophor but type of the lesions is not different. Bronchiolar lesions were moderate compare to the effects of 3-MI in some other animals. Severity of vascular lesions in Propylene glycol dissolved 3-MI was greater than groups that received the Cremophor dissolved 3-MI. Although the vascular injuries were not that much noticeable at all.(AU)

Comparative pathologic and stereologic study of respiratory system in mice following administration of 3-methyl indole dissolved in propylene glycol and cremophor EL and LD50 determination

Background: 3-Methyl indole (Skatole, 3-MI) is produced by microfloral fermentation of tryptophan in rumen and production of that has relation with the onset of respiratory problems in cattle. The aim of this study was to compare complications of 3-MI dissolved in two solvents, Cremophor and Propylene Glycol on BALB/c mice by histopathologic and stereologic studies. Materials, Methods & Results: Female Balb/C mice 56 days of age (23 - 27 g) were divided into 13 groups of eight and had access to food and water ad libitum. Mice were housed in plastic cages (4 per cage) with wire bar lids on bedding of sawdust in an air-conditioned room with 12 h light: dark cycles. After a 7-day acclimation period, for 5 groups, Mice were injected with 400, 500, 600, 700 and 800 mg/kg from solution of 3-MI in propylene glycol and similarly for 5 other groups with Cremophor. As well as 2 groups were injected with Propylene glycol and Cremophor with the dosage that is necessary for solving the highest dose of 3-MI. One group received normal saline with the volume equal with Cremophor (drug vehicle) group. Briefly, 125 mg of 3-MI was dissolved per mL of sterile filtered Propylene glycol and 30 mg of 3-MI was dissolved per mL of sterile filtered Cremophor. Once injected intra peritoneally, mice were monitored 3-4 h for external reaction signs from the injection. LD50 was determined 610.16 mg/kg 3-Methylindole and 687.5 mg/kg 3-Methylindole dissolved in Propylene glycol and Cremophor respectively with linear regression. Increase in respiration rate, tachypnea and shallow respiration was observed in clinical examination. In necropsy, alveolar and bronchial hyperemia was significant in lungs. Some superficial wounds were observed in upper respiratory airways. Trachea and Hungarian airways were severely hyperemic. There were some debris’s in airways canals. We couldn’t find any lesion in other organs. Histopathology showed noticeable alveolar edema and emphysema, type I pneumocytes necrosis, Slight endothelial lesions, rare degeneration of type II pneumocytes and raised nutrophil infiltration around vessels were observed in higher dosages of both groups. Moderate interstitial edema, hyperemia and increase of alveolar macrophages were observed too. Increase of lymphocytes was noticed after the dose 600 mg/kg moderately on a dose dependent manner. There was a Hyaline membrane in the wall of air sacs. Endothelial capillary damage in Cremophor dissolved 3-MI groups were slightly lower. Although damage to the vessels was not that much progressed in both groups. Stereologic study of type II pneumocytes showed a significant increase in the percentage of them in alveoli of treatment groups in a dose dependent manner compare to control and drug vehicle groups. At the highest dose (800 mg/kg) the group with Propylene glycol as solvent had significant difference with Cremophor dissolved 3-Methyl indole group and epithelialization was more severe in that. Bronchiole injuries raised in a dose dependent manner in both treatment groups. Discussion: The results of this research indicate that intraperitoneal infusion of 3-MI dissolved in Propylene glycol and Cremophor cause noticeable changes in the respiratory systems of mice. Effects of 3-MI in Propylene glycol is more severe than 3-MI dissolved in Cremophor but type of the lesions is not different. Bronchiolar lesions were moderate compare to the effects of 3-MI in some other animals. Severity of vascular lesions in Propylene glycol dissolved 3-MI was greater than groups that received the Cremophor dissolved 3-MI. Although the vascular injuries were not that much noticeable at all.

Cell migration induced by Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) major and Leishmania (Viannia) braziliensis into the peritoneal cavity of BALB/c mice

In American cutaneous leishmaniasis, the initial infection phase is characterized by recruitment of neutrophils and monocytes. The migration of these cells in response to the presence of Leishmania in the peritoneum of affected animals remains unclear. The objective of this study was to investigate cell migration to the peritoneum of BALB/c mice after infection with Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) major. Initially, Leishmania spp. was intraperitoneally inoculated in five groups of six animals each and the cell migration was analyzed 0, 3, 6, 12, 24 and 48 hours after infection. Different cell counts were performed with a staining kit and showed a higher percentage of polymorphonuclear than mononuclear cells in all three species studied. The total cell count revealed peak migration in L. (L.) amazonensis and L. (L.) major at six hours, and in L. (V.) braziliensis at 12 hours. These results suggest that factors released from different cell types probably act by attracting polymorphonuclear cells, with the peak migration most likely depending on the species of Leishmania inoculated into the host.(AU)

Cytokine and antibody production during murine leptospirosis

The aim of the present study was to investigate the kinetics of humoral and cellular responses during leptospirosis. We observed that the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) was associated with antibody production and bacterial recovery, and the compromising of both TNF-alpha and IL-6 in the immunopathogenesis of leptospirosis during an experimental infection of BALB/c mice inoculated with Leptospira interrogans serovar Canicola was verified. Results showed higher levels of TNF-alpha and IL-6 in the initial phase of infection, in which the greatest bacterial clearance was observed. However, when the bacterial recovery was compared with the kinetics of the production of antibodies, the results revealed a kinetics proportionally inverted to antibody production. This fact may be related to some inhibitory factor which could be responsible for the selective suppression of the cellular immune response. We concluded that during leptospirosis there was a greater mobilization of the cellular immune response activity, mainly in the initial phase of the infectious process, for posterior involvement of the humoral response, and that both TNF-alpha and IL-6 could be associated with the immunopathogenesis of the disease.

Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts

Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH) in resistant versus susceptible inbred mice. Non-infective (procyclic) promastigotes of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible) and C57BL/6 (resistant) mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.

Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.

Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts

Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH) in resistant versus susceptible inbred mice. Non-infective (procyclic) promastigotes of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible) and C57BL/6 (resistant) mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.

Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.

Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts

Little is known on the epitopes derived from metacyclic promastigotes of Leishmania that are important on the regulation or destruction of the parasite, as targets of immune attack in the vertebrate host. In this study we investigated an alternative method to obtain metacyclic promasigotes of Leishmania major, as evaluated by the course of infection and delayed-type hipersensitivity (DTH) in resistant versus susceptible inbred mice. Non-infective (procyclic) promastigotes of L. major recently transformed from tissue amastigotes were attached to a negatively charged glass-wool column, whereas metacyclic promastigotes were not bound to columns and could be easily recovered. Optimal chromatography conditions were validated through statistical analyses. Parasite average yield from glass wool columns and promastigote viability were estimated by light microscopy. Metacyclic promastigotes yielded 43.5% to 57.5%. Different patterns of cutaneous lesions were obtained in BALB/c (susceptible) and C57BL/6 (resistant) mice, the former with highly infective lesions induced by metacyclic promastigotes. DTH responses proved to be higher in groups of C57BL/6 mice which were infected with metacyclic promastigotes. These results indicate that the new method could be integrated with the investigation of metacyclogenesis of Leishmania in vivo.

Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.