Hepatoprotective effect of the aqueous extract of Simarouba amara Aublet (Simaroubaceae) stem bark against carbon tetrachloride (CCl4)-induced hepatic damage in rats.

Simarouba amara stem bark decoction has been traditionally used in Brazil to treat malaria, inflammation, fever, abdominal pain, diarrhea, wounds and as a tonic. In this study, we investigate the hepatoprotective effects of the aqueous extract of S. amara stem bark (SAAE) on CCl4-induced hepatic damage in rats. SAAE was evaluated by high performance liquid chromatography. The animals were divided into six groups (n = 6/group). Groups I (vehicle-corn oil), II (control-CCl4), III, IV, V and VI were pretreated during 10 consecutive days, once a day p.o, with Legalon® 50 mg/kg b.w, SAAE at doses 100, 250 and 500 mg/kg b.w, respectively. The hepatotoxicity was induced on 11th day with 2 mL/kg of 20% CCl4 solution. 24 h after injury, the blood samples were collected and their livers were removed to biochemical and immunohistochemical analyzes. The SAAE decreased the levels of liver markers and lipid peroxidation in all doses and increased the catalase levels at doses 250 and 500 mg/kg. Immunohistochemical results suggested hepatocyte proliferation in all doses. These results may be related to catechins present in SAAE. Thus, SAAE prevented the oxidative damage at the same time that increased regenerative and reparative capacities of the liver.

Acute toxicity and laxative activity of Aloe ferox resin

Aloe ferox Mill., Xanthorrhoeaceae, resin is the solid residue obtained by evaporating the latex that drains from the leaves transversally cut. Aloe ferox has been used in folk medicine as anti-inflammatory, immunostimulant, anti-bacterial, anti-fungal, antitumor, laxative and to heal wounds and burns. The effects of the oral administration of A. ferox resin (10, 25, 50, 100 and 200 mg/kg) were evaluated on intestinal transit in mice and its acute toxicity (5.0 g/kg) in Wistar rats. The hydroxyanthracene derivatives present in the resin were expressed as aloin, identified by thin layer chromatography and quantified by spectrophotometry. The aloin (Rf 0.35) was identified and the percentage of hydroxyanthracene derivates expressed as aloin was 33.5%. A. ferox resin extract (50, 100 and 200 mg/kg) increased the gastrointestinal motility at a 30 min interval at 93.5, 91.8 and 93.8%, respectively, when compared to control group (46.5%). A single oral dose of the A. ferox resin extract did not induce signs of toxicity or death. Thus, the results demonstrate that A. ferox has laxative activity and that it is nontoxic, since LD50 could not be estimated and it is possibly higher than 5.0 g/kg.