RESUMO
The aim of this study was to evaluate the antioxidant and hepatoprotective activity of Croton hypoleucus (EC). The present work reports the first pharmacological, toxicological, and antioxidant studies of EC extract on liver injury. Liver necrosis was induced by thioacetamide (TAA). Five groups were established: Croton Extract (EC), thioacetamide (TAA), Croton extract with thioacetamide (EC + TAA), vitamin E with thioacetamide (VE + TAA) and the positive control and vehicle (CT). For EC and EC + TAA, Wistar rats (n = 8) were intragastrically pre-administered for 4 days with EC (300 mg/kg.day) and on the last day, EC + TAA received a single dose of TAA (400 mg/kg). At 24 h after damage induction, animals were sacrificed. In vitro activity and gene expression of superoxide dismutase (SOD), catalase (Cat), and Nrf2 nuclear factor were measured. The results show that EC has medium antioxidant properties, with an IC50 of 0.63 mg/mL and a ferric-reducing power of 279.8 µM/mg. Additionally, EC reduced hepatic damage markers at 24 h after TAA intoxication; also, it increased SOD and Cat gene expression against TAA by controlling antioxidant defense levels. Our findings demonstrated the hepatoprotective effect of EC by reducing hepatic damage markers and controlling antioxidant defense levels. Further studies are necessary to identify the mechanism of this protection.
Assuntos
Antioxidantes , Doença Hepática Induzida por Substâncias e Drogas , Croton/química , Extratos Vegetais , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Catalase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Modelos Animais de Doenças , Masculino , Fator 2 Relacionado a NF-E2/metabolismo , Necrose , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Tioacetamida/toxicidadeRESUMO
Geranium schiedeanum has been used in traditional therapies as an antiseptic, antipyretic, and as analgesic. The present study was designed to evaluate the pretreatment with G. schiedeanum total extract (GS) and its active metabolites on stimulating the endogenous antioxidant defense system (EADS): catalase (Cat), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione reduction index (RI GSH/GSSG) in rat liver treated with a sublethal dose (6.6 mmol/Kg) of thioacetamide (TAA) in order to probe the capacity of GS and the active compounds to reduce liver injury. This was assessed by measuring aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (BILT) in rats pretreated or not with TAA, and pretreated or not with GS and its metabolites. The results showed that GS was able to induce the production of EADS enzymes, increasing redox index GSH/GSSG at 24 and 48 h after intoxication, and both the extract and the ellagic acid exhibited a significant reduction of hepatic damage markers. Our data confirmed the hepatoprotective effect of GS and its metabolites, like ellagic acid, support the possible use of this extract in the treatment of liver injury.
RESUMO
One of the major components of some geraniums is geraniin, described by its discoverer as crystallizable tannin, well known as an excellent antioxidant, and also found in fruits such as pomegranate. Recently, natural antioxidants have attracted great attention from consumers over the world due to their lower toxicity than synthetics. But geraniin is not a stable compound, and also is difficult to obtain, that is why in the present study we obtained acetonylgeraniin from Geranium schideanum (Gs), a stable acetone condensate of geraniin. In the present study the effect of Gs acetone-water extract was studied in reference to postnecrotic liver regeneration induced by thioacetamide (TA) in rats. Two months male rats were pretreated with daily dose of Gs extract for 4 days (300 mg/kg) and the last day also were intraperitoneally injected with TA (6.6 mmol/kg). Samples of blood were obtained from rats at 0, 24, 48, 72 and 96 h following TA intoxication. The pre-treatment with the crude extract in the model of thioacetamide-induced hepatotoxicity in rats decreased and delayed liver injury by 66% at 24 h. This result suggests that Gs extract may be used as an alternative for reduction of liver damage. On the other hand, acute toxicity study revealed that the LD50 value of the Gs extract is more than the dose 5000 mg/kg in rats, according to the Lorke method.