Preclinical Toxicity Evaluation of Quassia amara Extract with Potential Antimycobacterial Activity
This study aimed to evaluate the oral acute and sub chronic toxicity of Quassia amara (Q. amara) extract. For the acute toxicity study, six male and six female rats received 2000 and 5000 mg/kg Q. amara extract. Rats were observed for 14 days; after sacrifice, liver, kidneys, lung, spleen and heart were submitted to macroscopic analysis. No death occurred and just the liver presented significant difference compared to the control group. For subchronic toxicity, eight groups of 6 male and 6 female rats received 200, 400 and 800 μg/mL of extract of Q. amara. Prothrombin time, bilirubin, urea, creatinine and gamma glutamyl transpeptidase (γ-GT), aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) were used as markers of renal and hepatobiliary function, respectively. The male showed a slight rise in serum bilirubin and creatinine and the female slight rise of AST, ALT and ALP activities. The urinalyses (pH, density, glucose and leukocytes) showed no change relative to the control. The NOAEL of 35 mg/kg and RfD 0.35 mg/kg/day encourage us to isolate the active principles in order to discover which molecules of this extract showed better antimycobacterial activity.
Anti-hiperglycemic effect of Quassia amara (Simaroubaceae) in normal and diabetic rats
The anti-hyperglycemic effect of wood powder of Quassia amara (QA) was evaluated in normal and in alloxan diabetes-induced rats. After a 12 h fast and glycemic check, the animals were orally given 0.9% of saline (control group), metformin (500 mg/kg) or QA (200 mg/kg) and, 30 minutes later, they received an oral glucose dose (1g/kg). The blood glucose level was measured after 30, 60, 90 and 120 minutes. From the oral glucose dose, QA showed anti-hyperglycemic effects, similar to metformin, only in the diabetic animals (p<0.01) when compared to the control group. Although the anti-hyperglycemic mechanism of action of QA was not investigated, a mechanism similar to metformin can be suggested, since both presented similar results for the conditions tested, that is, normal and diabetic rats. It is believed that the use of QA in diabetics could help to control the blood glucose levels and be useful as an alternative therapy.
Keywords: alloxan, anti-hyperglicemic effect, diabetes, Quassia amara