In vitro and in vivo effect of Eurycoma longifolia root extract on UDP-glucuronosyltransferase activity

The aim of this research was to evaluate the effects of Eurycoma longifolia root extract (ELE) on enzymes activity in thephase II drug metabolism on Sprague-Dawley (SD) rats, especially on uridine 5ʹ-diphospho-glucuronosyltransferase(UGT) activity, in vivo and in vitro. The UGT assay was performed as follows: for the in vivo study, the male SDrats were treated with ELE at doses ranging from 5 to 1,000 mg/kg b.w. and 5, 25, and 50 mg/kg b.w for acuteand sub-acute study, respectively. The ELE concentrations of 0.01 to 1,000 µg/ml were used for in vitro study. Thep-nitrophenol (pNP) that consumed in the glucuronidation process reflected the UGT activity and was calculated usingstandard curve of pNP. UGT enzyme activity was inhibited significantly (p < 0.01) by ELE extract in the male rat forboth acute and sub-acute experiments. ELE extract decreased the enzyme activity significantly (p < 0.01), at all theconcentrations tested in the in vitro experiment when compared to the negative control group. ELE had a lower activity(the IC50 of 0.74 µg/ml) as compared to Na diclofenac (positive control) with an IC50 of 0.17 µg/ml. Eurycomalongifolia decreased the UGT enzyme activity significantly (p < 0.01), both for in vivo and in vitro study

The potential of standardized quassinoid-rich extract of Eurycoma longifolia in the regulation of the oestrous cycle of rats

Objective: To evaluate the effects of Eurycoma longifolia (E. longifolia) standardized extract on the oestrous cycle, levels of reproductive hormones and histology of the ovaries of Sprague-Dawley rats. Methods: Female rats were orally treated with E. longifolia standardized extract at the dose levels of 2.5, 5.0, 10.0, 25.0, 50.0 and 100.0 mg/kg of body weight over 5 days. Vaginal smears were monitored daily within the duration and after withdrawal of the treatment before being sacrificed. The body weights of the females were recorded before and after the 5 days treatment. At the end of the experiments, blood samples were collected for determination of testosterone, oestradiol and progesterone levels. Ovaries were removed, weighed and examined for histomorphological changes. Results: The administration of E. longifolia standardized extract did not significantly alter the oestrous cycle of the rats during the 5 days treatment and after withdrawal of the treatments. This was supported by normal testosterone, oestradiol and progesterone levels as well as normal morphology of the ovaries. Conclusions: The data obtained showed that E. longifolia standardized extract did not exhibit any toxic effect on reproductive activities of female rats suggesting potential use in the management of infertility.