ABSTRACT
Long-term glucocorticoid therapy causes secondary osteoporosis leading to pathological fractures. Glucocorticoid action in bone is dependant upon the activity of 11beta-hydroxysteroid dehydrogenase type 1 enzyme [11beta-HSD1]. Piper sarmentosum is a local herb that possesses the ability to inhibit 11-betaHSD1 enzyme activity. We aimed to determine the effects of Piper sarmentosum water extract on 11-betaHSD1 expressions and activity in the bones of glucocorticoid-treated adrenalectomized rats. Forty male Sprague-Dawley rats [200-250 g] were used. Twenty-four animals were adrenalectomized and received intramuscular injection of dexamethasone [120 microg/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. Following two months treatment, dexamethasonetreated adrenalectomized rats had significantly lower 11beta-HSD1 dehydrogenase activity and higher 11beta-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 11beta-HSD1 dehydrogenase activity and lower 11beta-HSD1 expression in the bones. 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 11beta-HSD1 expression and activity, and may be used as prophylaxis for osteoporosis in patients on long-term glucocorticoid treatment