Hepatics alterations and genotoxic effects of Croton cajucara Benth (SACACA) in diabetic rats / Alterações hepáticas e efeitos genotóxicos do Croton cajucara Benth (SACACA) em ratos diabéticos

CONTEXT: Croton cajucara Benth is a plant found in Amazonia, Brazil and the bark and leaf infusions of this plant have been popularly used to treat diabetes and hepatic disorders. OBJECTIVES: This study investigated effects hepatics alterations and genotoxic and antidiabetic effect of Croton cajucara Benth bark extracts treatment in streptozotocin-induced diabetic rats. METHODS: Male Wistar rats were divided into six groups: control rats; control rats treated with Croton cajucara Benth extract during 5 and 20 days; diabetic rats, and diabetic rats treated with Croton cajucara Benth during 5 and 20 days. Diabetes was induced by a single intraperitoneal injection of streptozotocin (70 mg/kg). Eight weeks later we measured glucose, triglyceride, cholesterol and hepatic transaminases on blood. The bone marrow micronucleus assay was used to assess the genotoxic activity of Croton cajucara Benth. RESULTS: Treatment with aqueous extrat of Croton cajucara was able to significantly reduce levels of triglycerides in diabetic animals, however, did not modify significantly the levels of glucose and cholesterol in these animals. There was no significant elevation in liver transaminases in the control group treated with Croton cajucara Benth, as there was no genotoxic effect of treatment in this model. Our results did not show a significant effect on glucose and cholesterol reduction, the treatment was able to significantly reduce triclycerides plasmatic level. There was no significant alterations on hepatic transferase in the animals from the control group treated with Croton cajucara Benth. It was observed no genotoxic effect of the treatment in the model studied. CONCLUSION: In this study Croton cajucara bark extract showed absence of hepatotoxicity in this animal model and presented a hypolipidemic activity, and could be used to reverse dyslipidemia associated with diabetes and to prevent the cardiovascular complications that are very prevalent in diabetic patients.

CONTEXTO: Croton cajucara Benth é uma planta encontrada na Amazônia, Brasil. Infusões da casca e folhas desta planta são utilizadas popularmente no tratamento de diabetes e doenças hepáticas. OBJETIVOS: Este estudo investigou as alterações hepáticas e os efeitos genotóxicos da casca do extrato do Croton cajucara Benth em animais diabéticos induzidos por estreptozotocina. MÉTODOS: Ratos Wistar machos foram divididos em seis grupos: ratos controle, ratos controle tratados com extrato de Croton cajucara Benth durante 5 e 20 dias, ratos diabéticos e diabéticos tratados com Croton cajucara Benth durante 5 e 20 dias. O diabetes foi induzido por uma única injeção intraperitonial de estreptozotocina (70 mg/kg). Oito semanas mais tarde foram medidos os níveis de glicose, triglicerídios, colesterol e transaminases hepáticas no sangue. O teste do micronúcleo da medula óssea foi utilizado para avaliar a atividade genotóxica do Croton cajucara Benth. RESULTADOS: O tratamento com o extrato aquoso do Croton cajucara foi capaz de reduzir significativamente os níveis plasmásticos dos triglicerídios nos animais diabéticos, porém, não modificaram significativamente os níveis de glicose e colesterol nesses animais. Não houve elevação significativa nas transaminases hepáticas nos animais do grupo controle tratadas com Croton cajucara Benth, assim como também não houve efeito genotóxico do tratamento, no modelo estudado. CONCLUSÃO: O extrato aquoso da casca do Croton cajucara Benth foi hipolipemiante, sugerindo seu uso para prevenir as dislipidemias encontradas em pacientes diabéticos.

Micronuclei induced by reverse transcriptase inhibitors in mononucleated and binucleated cells as assessed by the cytokinesis-block micronucleus assay

This study evaluated the clastogenic and/or aneugenic potential of three nucleoside reverse transcriptase inhibitors (zidovudine - AZT, lamivudine - 3TC and stavudine - d4T) using the cytokinesis-block micronucleus (CBMN) assay in human lymphocyte cultures. All three inhibitors produced a positive response when tested in binucleated cells. The genotoxicity of AZT and 3TC was restricted to binucleated cells since there was no significant increase in the frequency of micronuclei in mononucleated cells. This finding indicated that AZT and 3TC caused chromosomal breakage and that their genotoxicity was related to a clastogenic action. In addition to the positive response observed with d4T in binucleated cells, this drug also increased the frequency of micronuclei in mononucleated cells, indicating clastogenic and aneugenic actions. Since the structural differences between AZT and 3TC and AZT and d4T involve the 3' position in the 2'-deoxyribonucleoside and in an unsaturated 2',3',dideoxyribose, respectively, we suggest that an unsaturated 2', 3', dideoxyribose is responsible for the clastogenic and aneugenic actions of d4T.