The Effects of Piper Sarmentosum Water Extract on the Expression and Activity of 11 beta-Hydroxysteroid Dehydrogenase Type 1 in the Bones with Excessive Glucocorticoids

Background: Long-term glucocorticoid therapy causes secondary osteoporosis leading to pathological fractures. Glucocorticoid action in bone is dependant upon the activity of 11 beta-hydroxysteroid dehydrogenase type 1 enzyme (11 beta-HSD1). Piper sarmentosum is a local herb that possesses the ability to inhibit 11-beta HSD1 enzyme activity. We aimed to determine the effects of Piper sarmentosum water extract on 11-beta HSD1 expressions and activity in the bones of glucocorticoid-treated adrenalectomized rats. Methods: Forty male Sprague-Dawley rats (200-250 g) were used. Twenty-four animals were adrenalectomized and received intramuscular injection of dexamethasone (120 mu g/kg/day). They were simultaneously administered with either Piper sarmentosum water extract (125 mg/kg/day), GCA (120 mg/kg/day) or distilled water as vehicle by oral gavage for two months. Eight animals were sham`-operated and given vehicle daily, i. e. intramuscular olive oil and oral distilled water. Results: Following two months treatment, dexamethasonetreated adrenalectomized rats had significantly lower 11 beta-HSD1 dehydrogenase activity and higher 11 beta-HSD1 expression in the femoral bones compared to the sham-operated and baseline group. The rats supplemented with Piper sarmentosum water extract had significantly higher 11 beta-HSD1 dehydrogenase activity and lower 11 beta-HSD1 expression in the bones. Conclusion: The results showed that Piper sarmentosum water extract had the ability to prevent glucocorcoticoid excess in the bones of glucocorticoid-treated adrenalectomized rats through the local modulation of 11 beta-HSD1 expression and activity, and may be used as prophylaxis for osteoporosis in patients on long`-term glucocorticoid treatment.