Cytotoxic Activity and Lymphocyte Subtypes in Mice Selected for Maximal and Minimal Inflammatory Response after Transplantation of B16F10 and S91 Melanoma Cells.

AIRmax and AIRmin mice strains were selected according to the intensity of their acute inflammatory responsiveness. Previous studies have shown that AIR mice differ in their resistance to chemically induced skin tumors and in the development of melanoma metastases, in addition to differences in neutrophil and NK cells activity. In the present work, we aimed to evaluate whether the difference of susceptibility to murine melanoma is associated with NK cytotoxic activity against Yac.1 cells and lymphocyte subsets. Mice were subcutaneously inoculated with B16F10 or S91 melanoma cells. After 7, 14, or 30 days, the animals were euthanized to analyze the number of lymphocyte subsets, cytotoxic activity, and number of cytokine-producing spleen cells. AIRmax mice presented a higher number of CD4+/CD25+ cells than that of AIRmin mice following inoculation of B16F10 cells, whereas inoculation of S91 cells reduced CD4+/CD25+ and increased TCD8+ cell subsets in the AIRmax mice. AIRmax mice had a higher number of interleukin (IL)-10- and IL-12-producing cells and a lower number of interferon-γ-producing cells than those of AIRmin mice at 30 days. The cytotoxic activity of nonadherent spleen cells was similar in both the AIR strains. These results suggest that melanoma cells can induce different responses in AIR mice, possibly owing to alterations in regulatory mechanisms, such as the action of CD4+/CD25+ regulatory T cells and IL-10, in AIRmax mice.

Cytotoxic activity and lymphocyte subtypes in mice selected for maximal and minimal inflammatory response after transplantation of B16F10 and S91 melanoma cells

AIRmax and AIRmin mice strains were selected according to the intensity of their acute inflammatory responsiveness. Previous studies have shown that AIR mice differ in their resistance to chemically induced skin tumors and in the development of melanoma metastases, in addition to differences in neutrophil and NK cells activity. In the present work, we aimed to evaluate whether the difference of susceptibility to murine melanoma is associated with NK cytotoxic activity against Yac.1 cells and lymphocyte subsets. Mice were subcutaneously inoculated with B16F10 or S91 melanoma cells. After 7, 14, or 30 days, the animals were euthanized to analyze the number of lymphocyte subsets, cytotoxic activity, and number of cytokine-producing spleen cells. AIRmax mice presented a higher number of CD4+/CD25+ cells than that of AIRmin mice following inoculation of B16F10 cells, whereas inoculation of S91 cells reduced CD4+/CD25+ and increased TCD8+ cell subsets in the AIRmax mice. AIRmax mice had a higher number of interleukin (IL)-10- and IL-12-producing cells and a lower number of interferon-γ–producing cells than those of AIRmin mice at 30 days. The cytotoxic activity of nonadherent spleen cells was similar in both the AIR strains. These results suggest that melanoma cells can induce different responses in AIR mice, possibly owing to alterations in regulatory mechanisms, such as the action of CD4+/CD25+ regulatory T cells and IL-10, in AIRmax mice.

First phytochemical study and biological activity of the leaves ethanolic extract from Cissus spinosa Cambess / Primeiro estudo fitoquímico e atividade biológica do extrato etanólico de folhas de Cissus spinosa Cambess

Aims: The objective of this study was to identify the phytochemical profile and to evaluate the biological effects of the crude ethanolic extract (EE) and the ethanolic fraction (EF) of leaves of the species Cissus spinosa Cambess, after oxidative stress induced by cyclophosphamide (CP) in mice. Methods: Phytochemical profile was performed detecting functional groups and, analysis of total flavonoids and phenols concentration, as well as the antiradical activity in EE and EF. The phytochemical characterization was done for the identification of flavonoids present in the leaves of the plant. In the biochemical tests, hematological parameters, glucose, total cholesterol, creatinine, alkaline phosphatase and aminotransferases dosages in plasma, enzymatic and non--enzymatic antioxidants and lipid damage marker were evaluated in different tissues (liver, kidney and heart), besides genotoxic and immunological analyzes. The animals received 15 days of treatment, via gavage, with EE (50 mg kg-1) or EF (50 mg kg-1) and on the 15th day, an intraperitoneal injection of CP (100 mg kg-1) or saline (0.9%). After 24 h the last treatment, the animals were anesthetized for blood withdrawal, sacrificed and removal of the organs. Results: In the phytochemical analyzes, the presence of alkaloids, flavonoids and phenols was identified, the latter presented a higher concentration for EF. Eight flavonoids were identified - Rutin, Quercetin-3-ß-D-glucoside, Quercitrin, Taxifolin, Quercetin, Canferol, Luteolin and Apigenin. In the biochemical analyzes, in general, EE showed a better antioxidant action against oxidative damages, hypoglycemic and antitilipemic action when comparing with EF, probably due to the synergism caused by flavonoids. It was observed the reduction and an increase of micronucleated polychromatic erythrocytes, due to the action of antioxidant compounds and alkaloids present in the plant, also considering the question of the seasonal period that directly interferes in the production of these compounds. In the immunological analysis, the extracts did not stimulate the spontaneous production of oxygen peroxide (H2 O2) and nitric oxide (NO•). Conclusions: Other studies, such as the variation of the chemical composition of the plant by local seasonality, hypoglycemic and antilipemic action, should be carried out to better delineate the biological action present in this plant.

Objetivos: O objetivo deste estudo foi identificar o perfil fitoquímico e avaliar os efeitos biológicos do extrato etanólico bruto (EE) e da fração etanólica (EF) das folhas da espécie Cissus spinosa Cambess, após estresse oxidativo induzido pela ciclofosfamida. (CP) em camundongos. Métodos: O perfil fitoquímico foi realizado detectando grupos funcionais e, análise da concentração de flavonoides e fenóis totais, bem como a atividade antirradical em EE e EF. A caracterização fitoquímica foi realizada para a identificação de flavonoides presentes nas folhas da planta. Nos testes bioquímicos, os parâmetros hematológicos, as dosagens de glicose, colesterol total, creatinina, fosfatase alcalina e aminotransferases no plasma, os antioxidantes enzimáticos e não enzimáticos e o marcador de dano lipídico foram avaliados em diferentes tecidos (fígado, rim e coração), além de análises genotóxicas e imunológicas. Os animais receberam 15 dias de tratamento, via gavagem, com EE (50 mg kg-1) ou EF (50 mg kg-1) e no 15º dia, injeção intraperitoneal de CP (100 mg kg-1) ou soro fisiológico (0,9%) . Após 24 h do último tratamento, os animais foram anestesiados para retirada do sangue, sacrificados e após a retirada dos órgãos. Resultados: Nas análises fitoquímicas, identificou-se a presença de alcaloides, flavonoides e fenóis, estes últimos apresentaram maior concentração para EF. Oito flavonoides foram identificados - rutina, quercetina-3-ß--D-glicosídeo, quercitrina, taxifolina, quercetina, canferol, luteolina e apigenina. Nas análises bioquímicas, em geral, o EE apresentou melhor ação antioxidante contra os danos oxidativos, ação hipoglicemiante e antitilipêmica quando comparada à EF, provavelmente devido ao sinergismo causado pelos flavonoides. Observou-se a redução e um aumento de eritrócitos policromáticos micronucleados, devido à ação de compostos antioxidantes e alcaloides presentes na planta, considerando também a questão do período sazonal que interfere diretamente na produção desses compostos. Na análise imunológica, os extratos não estimularam a produção espontânea de peróxido de oxigênio (H2O2) e óxido nítrico (NO•). Conclusões: Outros estudos, como a variação da composição química da planta por sazonalidade local, ação hipoglicemiante e antilipêmica, devem ser realizados para melhor delineamento da ação biológica presente nesta planta.

Evaluation of antimutagenic and cytotoxic activity of skin secretion extract of Rhinella marina and Rhaebo guttatus (Anura, Bufonidae) / Avaliação da atividade antimutagênica e citotóxica da secreção cutânea de Rhinella marina e Rhaebo guttatus (Anura, Bufonidae)

The skin secretion from toads of the Bufonidae family has great potential in the search for new active compounds to be used as drug candidates in treating some diseases, among them cancer. In this context, this study aimed to evaluate the cytotoxic and antimutagenic activity of the parotoid gland secretion extracts of Rhinella marina and Rhaebo guttatus, as well as biochemically analyze transaminases and serum creatinine for liver and renal damage, respectively. Cytotoxicity was performed by the colorimetric method based on MTT (3- [4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide) with different concentrations of the extracts in Walker or splenic tumor cell cultures from rats and mice. The micronucleus test was performed with male Swiss mice treated orally with the extracts for 15 days, and then intraperitoneally with N-ethyl-N-nitrosurea (50 mg kg-1). Micronucleated polychromatic erythrocytes (MNPCE) were evaluated in bone marrow. The extracts showed cytotoxic activity in the evaluated cells. There was a significant reduction in the frequency of MNPCE (R. marina = 56% and R. guttatus = 75%, p < 0.001), indicating antimutagenic potential of the extracts. The groups treated only with extract showed an increase in MNPCE frequency, evidencing mutagenic potential. Biochemical analyzes showed no significant difference between treatments. Thus, under our experimental conditions, the extracts of R. marina and R. guttatus skin secretions presented chemopreventive potential for cancer. (AU)

A secreção cutânea de anuros da família Bufonidae tem grande potencial na busca de novos compostos ativos para utilização como fármacos candidatos no tratamento de algumas doenças, entre elas o câncer. Neste contexto, este estudo teve como objetivo avaliar a atividade citotóxica e antimutagênica dos extratos da secreção da glândula parótida de Rhinella marina e Rhaebo guttatus, bem como a análise bioquímica de transaminases e creatinina séricas, para avaliar dano hepático e renal, respectivamente. A avaliação de citotoxicidade foi realizada pelo método colorimétrico baseado no MTT (3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide), com diferentes concentrações dos extratos em culturas de células do Tumor de Walker ou células esplênicas de rato e camundongo. O teste do micronúcleo foi realizado com camundongos Swiss machos que receberam tratamento oral com os extratos durante 15 dias, seguido de tratamento intraperitoneal com N-etil-N-nitrosuréia (50 mg kg-1). A frequência de eritrócitos policromáticos micronucleados (PCEMN) foi determinada em medula óssea. Os extratos apresentaram ação citotóxica nas células avaliadas. Houve uma redução significativa na frequência de PCEMN (R. marina = 56% e R. guttatus = 75%, p < 0,001), observando-se um potencial antimutagênico dos extratos. Os grupos tratados somente com os extratos apresentaram um aumento na frequência de PCEMNs, evidenciando um potencial mutagênico. As análises bioquímicas não apresentaram diferença significativa entre os tratamentos. Assim, nas condições experimentais testadas, as secreções cutâneas de R. marina e R. guttatus apresentaram potencial quimiopreventivo para câncer.(AU)

Evaluation of the antioxidant potential of Copaifera multijuga in Ehrlich tumor-bearing mice

Copaifera multijuga, commonly known as copaiba, is popularly used in the form of tea for various conditions due to the presence of antioxidant substances in its composition, which protect cells against damage caused by free radicals. Its oleoresin is also used as an anti-inflammatory and antitumoral agent. The present study investigated the antioxidant effect of the ethanolic extract of copaiba stem bark on Swiss mice inoculated with solid Ehrlich tumors. Mice were inoculated subcutaneously with 1x106 Ehrlich's tumor cells and treated via gavage with ethanolic extract of copaiba for thirty days, with doses varying between 100 and 200 mg kg-1. Biochemical analyses of enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST)], non-enzymatic antioxidants [reduced glutathione (GSH) and ascorbic acid (ASA)], substances reactive to thiobarbituric acid (TBARS) and protein carbonylation (carbonyl) in different tissues were significantly affected. The extract administered at 200 mg kg-1 presented higher antioxidant capacity in the liver, increased CAT, GST, GSH and decreased TBARS, as well as increased CAT activity and protein carbonylation in brain tissue. The results showed that the copaiba extract was able to reverse the oxidative stress caused by solid Ehrlich tumor, probably due to the presence of antioxidant compounds, and had potential antineoplasic effect after a 30-day treatment. (AU)

Natural killer activity of the spleen cells of Ehrlich tumor-bearing mice treated with Copaifera multijuga extract / Atividade natural killer das células esplênicas de camundongos portadores do tumor de Ehrlich tratados com extrato de Copaifera multijuga

AIMS: Copaifera multijuga Hayne oleoresin is commonly used in traditional medicine owing to its anti-inflammatory, antiseptic, antitumor, and antibacterial properties. However, little is known about the effect of the compounds from the bark of this plant. In this study, the immunomodulatory effect of the ethanolic extract of C. multijuga bark via natural killer activity of non-adherent spleen cells of Ehrlich tumor-bearing mice was evaluated. METHODS: Male Swiss mice were inoculated subcutaneously with 1×106 Ehrlich tumor cells (Ehrlich and Ehrlich/C. multijuga group) or phosphate buffered saline solution (control group and C. multijuga group) and treated orally daily with C. multijuga extract (200 mg kg-1, 0.1 mL per mouse, for the Ehrlich/C. multijuga and C. multijuga groups) or phosphate buffered saline solution (control group and Ehrlich group). The four experimental groups consisted in eight mice each and were organized in two sets, one treated for seven days and another treated for 14 days, totalizing 64 mice throughout the experiment. Twenty-four hours after the last oral administration, the mice were euthanized and the spleen tissue was isolated to prepare a non-adherent spleen cell suspension and to evaluate natural killer activity. Data are presented as the cell lysis percentage of Yac.1 target cells by non-adherent spleen cells. RESULTS: Treatment for seven days increased natural killer activity in the Ehrlich/C. multijuga group (21.20±8.89, p<0.05) compared to the control group (3.14±2.71, p<0.05); however, this effect was not maintained in the groups treated for 14 days (Control: 6.02±6.98, Ehrlich: 4.82±7.72, C. multijuga: 2.07±2.10, Ehrlich/C. multijuga: 2.01±1.63, p>0.05). CONCLUSIONS: Treatment for seven days with an ethanolic extract of C. multijuga bark enhanced the natural killer activity of non-adherent spleen cells from Ehrlich tumor-bearing mice.

OBJETIVOS: O óleo-resina de Copaifera multijuga Hayne é popularmente utilizado na medicina tradicional por suas propriedades antiinflamatória, antisséptica, antitumoral e antibacteriana. Entretanto, há poucos estudos sobre o efeito dos compostos obtidos da casca da planta. Assim, o objetivo deste trabalho foi avaliar o efeito imunomodulador do extrato etanólico da casca da C. multijuga na atividade natural killer das células esplênicas não aderentes de animais portadores do tumor de Ehrlich. MÉTODOS: Camundongos Swiss machos foram inoculados subcutaneamente com 1×106 células do tumor de Ehrlich (grupo Ehrlich e Ehrlich/C. multijuga) ou com solução salina tamponada (grupo controle e C. multijuga) e tratados diariamente (gavagem) com extrato de C. multijuga (200 mg kg-1, 0,1mL cada um, para os grupos Ehrlich/C. multijuga e C. multijuga) ou com solução salina tamponada (grupo controle e grupo Ehrlich). Os quatro grupos experimentais consistiram de oito animais cada e foram organizados em dois conjuntos, um tratado por sete dias e outro tratado por 14 dias, totalizando 64 animais durante todo o experimento. Após 24 horas do término do tratamento, os animais foram eutanasiados para obtenção da suspensão de células esplênicas não aderentes e avaliação da atividade natural killer. Os resultados são apresentados como porcentagem da lise celular das células alvo Yac.1 pelas células esplênicas não aderentes. RESULTADOS: A análise dos resultados demonstrou que aos sete dias de tratamento a C. multijuga aumentou a atividade natural killer no grupo Ehrlich/C. multijuga (21,20±8,89, p<0,05) em comparação ao grupo controle (3,14±2,71, p<0,05), entretanto tal efeito não foi mantido nos grupos tratados por 14 dias (Controle: 6,02±6,98; EHR: 4,82±7,72; C. multijuga: 2,07±2,10; EHR/C. multijuga: 2,01±1,63, p>0,05). CONCLUSÕES: Os resultados demonstraram que o tratamento com o extrato etanólico da casca de C. multijuga favoreceu a atividade natural killer das células esplênicas não aderentes dos animais portadores do tumor de Ehrlich apenas aos sete dias de tratamento.

Polysaccharide-rich fraction of Agaricus brasiliensis enhances the candidacidal activity of murine macrophages.

A polysaccharide-rich fraction (ATF) of medicinal mushroom Agaricus brasiliensis was evaluated on the candidacidal activity, H2O2 and nitric oxide (NO) production, and expression of mannose receptors by murine peritoneal macrophages. Mice received three intraperitoneal (i.p.) injections of ATF and after 48 h their peritoneal resident macrophages were assayed against Candida albicans yeast forms. The treatment increased fungicidal activity and it was associated with higher levels of H2O2, whereas NO production was not affected. We also found that the treatment enhances mannose receptor expression by peritoneal macrophages, which are involved in the attachment and phagocytosis of non-opsonized microorganisms. Treatment of animals with ATF was able to enhance the clearance of C. albicans during the first 6 h after the experimental i.p. infection. Our results suggest that this extract can increase host resistance against some infectious agents through the stimulation of microbicidal activity of macrophages.

Polysaccharide-rich fraction of Agaricus brasiliensis enhances the candidacidal activity of murine macrophages

A polysaccharide-rich fraction (ATF) of medicinal mushroom Agaricus brasiliensis was evaluated on the candidacidal activity, H2O2 and nitric oxide (NO) production, and expression of mannose receptors by murine peritoneal macrophages. Mice received three intraperitoneal (i.p.) injections of ATF and after 48 h their peritoneal resident macrophages were assayed against Candida albicans yeast forms. The treatment increased fungicidal activity and it was associated with higher levels of H2O2, whereas NO production was not affected. We also found that the treatment enhances mannose receptor expression by peritoneal macrophages, which are involved in the attachment and phagocytosis of non-opsonized microorganisms. Treatment of animals with ATF was able to enhance the clearance of C. albicans during the first 6 h after the experimental i.p. infection. Our results suggest that this extract can increase host resistance against some infectious agents through the stimulation of microbicidal activity of macrophages.

Enhanced natural killer activity and production of pro-inflammatory cytokines in mice selected for high acute inflammatory response (AIRmax).

Strains of mice with maximal and minimal acute inflammatory responsiveness (AIRmax and AIRmin, respectively) were developed through selective breeding based on their high- or low-acute inflammatory responsiveness. Previous reports have shown that AIRmax mice are more resistant to the development of a variety of tumours than AIRmin mice, including spontaneous metastasis of murine melanoma. Natural killer activity is involved in immunosurveillance against tumour development, so we analysed the number and activity of natural killer cells (CD49b(+)), T-lymphocyte subsets and in vitro cytokine production by spleen cells of normal AIRmax and AIRmin mice. Analysis of lymphocyte subsets by flow cytometry showed that AIRmax mice had a higher relative number of CD49b(+) cells than AIRmin mice, as well as cytolytic activity against Yac.1 target cells. The number of CD3(+) CD8(+) cells was also higher in AIRmax mice. These findings were associated with the ability of spleen cells from AIRmax mice in vitro to produce higher levels of the pro-inflammatory cytokines tumour necrosis factor-alpha, interleukin-12p40 and interferon-gamma but not the anti-inflammatory interleukin-10. Taken together, our data suggest that the selective breeding to achieve the AIRmax and AIRmin strains was able to polarize the genes associated with cytotoxic activity, which can be responsible for the antitumour resistance observed in AIRmax mice.

Desenvolvimento de melanoma em animais selecionados pela intensidade de resposta inflamatória aguda (Airmax/Airmin): caracterização das células Natural Killer, NKT, Treg e perfil de citocinas / Development of melanoma in animals selected by the intensity of acute inflammatory response (Airmax/Airmin): characterization of Natural Killer cells, NKT, Treng and profile of cytokines

Animais selecionados de acordo com a intensidade da sua resposta inflamatória aguda (AIR) à poliacrilamida, foram inoculados s.c. com células de melanoma B16F10 ou S91. Aos 7, 14 ou 30 dias, os animais foram sacrificados para obtenção do baço e avaliação do número de células T, Treg, NK e NKT, por citometria de fluxo, e do perfil de algumas citocinas (ELISpot). Os resultados demonstraram que os animais AIRmax apresentaram maior incidência do melanoma B16F10, associado ao aumento do número de células Treg, e também incidência elevada do melanoma S91, associada ao aumento da produção IL-10 e redução de IFN-gama, em relação aos animais AIRmin. Estes resultados permitem inferir que a sensibilidade ao desenvolvimento de melanomas pode ser resultado de alterações nos mecanismos regulatórios da resposta imune, que neste caso, inibiram o desenvolvimento de uma resposta eficiente nos animais AIRmax.