The aim of this study was to investigate the acute (one-day treatment) effect of a methanol extract of
Orthosiphon stamineus, Benth on glutathione-S-transferase (GST) activity in streptozotocin (STZ)-induced diabetic young male and female Sprague Dawley (SD) rats. The methanol extract of O. stamineus was administered orally (5, 31.25, 125 and 500 mg/kg) to diabetic rats, and the effect on GST activity was measured by the method of Habig et al. (1974). No lethality and no significant changes in body weight and water intake were observed in the treated group as compared to the control group. A significant increase in the activity of GST was observed in the liver S-9 cytosolic fraction of diabetic male SD rats treated with 125 mg/kg (P < 0.01) and 500 mg/kg (P < 0.01) of the methanol extract O. stamineus. Administration of 500 mg/kg (P < 0.01) of the methanol extract of O. stamineus to diabetic female SD rats increased GST activity when compared to the control group. This study indicates that the methanol extract of O. stamineus could affect the activity of GST in rat liver and the effect seen was dose-dependent.
The objective of this study was to examine the effects of different storage conditions of star fruit (Averrhoa carambola) juice on the activity of acetylcholinesterase in various organs of Sprague Dawley (SD) rats. The effect of oral administration of star fruit on serum lipid profiles was also examined in this study. A total of 15 female rats were assigned into three groups with five animals per group (n=5). The first group served as control group and given only distilled water (vehicle) while the other two groups were given different star fruit preparations, i.e. freshly prepared star fruit juice and after 3 hours storage, respectively. From the results obtained, a significant decrease in the hepatic acetylcholinesterase activity was observed in rats treated with star fruit juice. In conclusion, the star fruit juice at different storage conditions is selectively targeted on the acetylcholinesterase activity in rat liver but not in kidney and heart.