Brazilian green propolis suppresses acetaminophen-induced hepatocellular necrosis by modulating inflammation-related factors in rats.

Propolis is a resin-like material produced by honey bees from bud exudates and sap of plants and their own secretions. An ethanol extract of Brazilian green propolis (EEBGP) contains prenylated phenylpropanoids and flavonoids and has antioxidative and anti-inflammatory effects. Acetaminophen (N-acetyl-p-aminophenol; APAP) is a typical hepatotoxic drug, and APAP-treated rats are widely used as a model of drug-induced liver injury. Oxidative stress and inflammatory reactions cause APAP-induced hepatocellular necrosis and are also related to expansion of the lesion. In the present study, we investigated the preventive effects of EEBGP on APAP-induced hepatocellular necrosis in rats and the protective mechanism including the expression of antioxidative enzyme genes and inflammation-related genes. A histological analysis revealed that administration 0.3% EEBGP in the diet for seven days reduced centrilobular hepatocellular necrosis with inflammatory cell infiltration induced by oral administration of APAP (800 mg/kg) and significantly reduced the area of necrosis. EEBGP administration did not significantly change the mRNA expression levels of antioxidant enzyme genes in the liver of APAP-treated rats but decreased the mRNA expression of cytokines including Il10 and Il1b, with a significant difference in Il10 expression. In addition, the decrease in the mRNA levels of the Il1b and Il10 genes significantly correlated with the decrease in the percentage of hepatocellular necrosis. These findings suggest that EEBGP could suppress APAP-induced hepatocellular necrosis by modulating cytokine expression.

Synergetic effect of chitosan and vitamin C on the oxidative enzyme status in rat exposed to lead acetate / Efeito sinérgico do chitosano e da vitamina C no estado da enzima oxidativa em ratos expostos ao acetato de chumbo

This article discusses the research results on the synergetic effect of chitosan and vitamin C in overcoming free radical effect due to blood lead (Pb2+) accumulation. Blood lead level and enzymatic activities of superoxide dismutase (SOD), catalase oxidase (CAT), and Glutathione peroxidase (GPx) were used as the main parameters. Thirty adult male albino rats were divided into six groups. Group 1 was normal control group; group 2 was the negative control group treated with lead acetate at 175 mg kg-1 body weight (BW). Group 3 was treated with 64 mg kg-1 BW of chitosan day-1. Group 4, 5, and 6 were treated with chitosan and vitamin C combination at the dose of 100, 200, and 300 mg kg-1 BW, respectively. All groups were inducted using 175 mg kg-1 BW of Pb-acetate, excluding control group. Results showed that chitosan and vitamin C treatment at the dose of 300 mg kg-1 BW decreased blood Pb2+ level in rats exposed to Pb-acetate. The combination also significantly increased enzymatic activities from SOD, CAT, and GPx compared to the other groups. In conclusion, the combination of chitosan and vitamin C could elevate the several antioxidative enzymes activities in Pb-acetate induced rats.

Este artigo discute os resultados da pesquisa sobre o efeito sinérgico da quitosana e da vitamina C na superação do efeito dos radicais livres devido ao acúmulo de chumbo no sangue (Pb2+). O nível de chumbo no sangue e as atividades enzimáticas de superóxido dismutase (SOD), catalase oxidase (CAT) e glutationa peroxidase (GPx) foram utilizados como parâmetros principais. Trinta ratos albinos adultos foram divididos em seis grupos. Grupo 1 foi grupo controle normal; o grupo 2 foi o grupo controle negativo tratado com acetato de chumbo a 175 mg kg-1 de peso corporal (PC). O grupo 3 foi tratado com 64 mg kg-1 PC de quitosana dia-1. Os grupos 4, 5 e 6 foram tratados com combinação de quitosana e vitamina C nas doses de 100, 200 e 300 mg kg-1 PC, respectivamente. Todos os grupos foram induzidos usando 175 mg kg-1 de PC de Pb-acetato, excluindo o grupo controle. Os resultados mostraram que o tratamento com quitosana e vitamina C na dose de 300 mg kg-1 PC diminuiu o nível de Pb2+ no sangue em ratos expostos ao acetato de Pb. A combinação também aumentou significativamente as atividades enzimáticas de SOD, CAT e GPx em comparação com os outros grupos. Em conclusão, a combinação de quitosana e vitamina C pode elevar as várias atividades das enzimas antioxidativas em ratos induzidos com acetato de Pb.

Synergetic effect of chitosan and vitamin C on the oxidative enzyme status in rat exposed to lead acetate / Efeito sinérgico do chitosano e da vitamina C no estado da enzima oxidativa em ratos expostos ao acetato de chumbo

This article discusses the research results on the synergetic effect of chitosan and vitamin C in overcoming free radical effect due to blood lead (Pb2+) accumulation. Blood lead level and enzymatic activities of superoxide dismutase (SOD), catalase oxidase (CAT), and Glutathione peroxidase (GPx) were used as the main parameters. Thirty adult male albino rats were divided into six groups. Group 1 was normal control group; group 2 was the negative control group treated with lead acetate at 175 mg kg-1 body weight (BW). Group 3 was treated with 64 mg kg-1 BW of chitosan day-1. Group 4, 5, and 6 were treated with chitosan and vitamin C combination at the dose of 100, 200, and 300 mg kg-1 BW, respectively. All groups were inducted using 175 mg kg-1 BW of Pb-acetate, excluding control group. Results showed that chitosan and vitamin C treatment at the dose of 300 mg kg-1 BW decreased blood Pb2+ level in rats exposed to Pb-acetate. The combination also significantly increased enzymatic activities from SOD, CAT, and GPx compared to the other groups. In conclusion, the combination of chitosan and vitamin C could elevate the several antioxidative enzymes activities in Pb-acetate induced rats.(AU)

Este artigo discute os resultados da pesquisa sobre o efeito sinérgico da quitosana e da vitamina C na superação do efeito dos radicais livres devido ao acúmulo de chumbo no sangue (Pb2+). O nível de chumbo no sangue e as atividades enzimáticas de superóxido dismutase (SOD), catalase oxidase (CAT) e glutationa peroxidase (GPx) foram utilizados como parâmetros principais. Trinta ratos albinos adultos foram divididos em seis grupos. Grupo 1 foi grupo controle normal; o grupo 2 foi o grupo controle negativo tratado com acetato de chumbo a 175 mg kg-1 de peso corporal (PC). O grupo 3 foi tratado com 64 mg kg-1 PC de quitosana dia-1. Os grupos 4, 5 e 6 foram tratados com combinação de quitosana e vitamina C nas doses de 100, 200 e 300 mg kg-1 PC, respectivamente. Todos os grupos foram induzidos usando 175 mg kg-1 de PC de Pb-acetato, excluindo o grupo controle. Os resultados mostraram que o tratamento com quitosana e vitamina C na dose de 300 mg kg-1 PC diminuiu o nível de Pb2+ no sangue em ratos expostos ao acetato de Pb. A combinação também aumentou significativamente as atividades enzimáticas de SOD, CAT e GPx em comparação com os outros grupos. Em conclusão, a combinação de quitosana e vitamina C pode elevar as várias atividades das enzimas antioxidativas em ratos induzidos com acetato de Pb.(AU)

Physiological and molecular responses to drought stress in rubber tree (Hevea brasiliensis Muell. Arg.).

Plant drought stress response and tolerance are complex biological processes. In order to reveal the drought tolerance mechanism in rubber tree, physiological responses and expressions of genes involved in energy biosynthesis and reactive oxygen species (ROS) scavenging were systematically analyzed following drought stress treatment. Results showed that relative water content (RWC) in leaves was continuously decreased with the severity of drought stress. Wilting leaves were observed at 7 day without water (dww). Total chlorophyll content was increased at 1 dww, but decreased from 3 dww. However, the contents of malondialdehyde (MDA) and proline were significantly increased under drought stress. Peroxidase (POD) and superoxide dismutase (SOD) activities were markedly enhanced at 1 and 3 dww, respectively. Meanwhile, the soluble sugar content was constant under drought stress. These indicated that photosynthetic activity and membrane lipid integrity were quickly attenuated by drought stress in rubber tree, and osmoregulation participated in drought tolerance mechanism in rubber tree. Expressions of energy biosynthesis and ROS scavenging systems related genes, including HbCuZnSOD, HbMnSOD, HbAPX, HbCAT, HbCOA, HbATP, and HbACAT demonstrated that these genes were significantly up-regulated by drought stress, and reached a maximum at 3 dww, then followed by a decrease from 5 dww. These results suggested that drought stress adaption in rubber tree was governed by energy biosynthesis, antioxidative enzymes, and osmoregulation.