Abstract
Eclipta prostrata (EP) is often prescribed in combination with glucocorticoid to treat glomerular nephritis, nephrotic syndrome, and IgA nephropathy in clinical practice of Traditional Chinese Medicine. Previous studies from our laboratory revealed that coadministration of EP significantly increased the plasma concentration of prednisolone while decreased the level of cotreated prednisone in rats. However, the underlying mechanism remains unclear. 11 β -Hydroxysteroid dehydrogenase (11 β -HSD) belongs to the family of oxidoreductases that catalyze the interconversion of prednisone to active prednisolone. Therefore, the current study aimed to investigate the effects of EP on the activity and expression of 11 β -HSD in rat liver and kidney. The results showed that oral administration of EP significantly increased the activity of 11 β -HSD I in the liver and 11 β -HSD II in the kidney by employing the microsomal incubation system. Moreover, gene and protein expressions of 11 β -HSD I and 11 β -HSD II were also increased in rat liver and kidney, respectively. These results suggest that the effects of EP on 11 β -HSD may attribute to the mechanism that administration of EP improves the efficacy and reduces adverse drug reactions of glucocorticoid in patients undergoing combinational therapy.