Ethanolic extract of Otostegia persica ameliorates bone loss in diabetic rats irrespective to its glucose lowering effect

The present study was conducted to investigate the effect of ethanolic extract of Otostegia persica on bone loss in streptozotocin (STZ)-treated diabetic rats. Forty male Wistar rats were randomly divided into five equal groups and treated as follows: group 1 (control); group 2 (STZ group), received STZ 50 mg/kg by a single IP injection; groups 3, 4, and 5 treated with STZ as mentioned above +200 mg/kg, 300 mg/kg, and 450 mg/kg of O. persica extract per day by oral gavage, respectively. On day 29, sera harvested and left femoral and tibiofibular bones were dissected for histomorphometric study, while right femoral and tibiofibular bones as well as L4 vertebrate were removed for determination of ash weight. Obvious hyperglycemia was seen in the STZ group as compared to the control. Administration of O. persica extract at the dosage of 300 mg/kg reversed the hyperglycemia. Alkaline phosphatase activity was markedly increased in all experimental groups as compared to control. Epiphyseal and metaphyseal trabecular width as well as epiphyseal bone area/tissue area significantly decreased in STZ group. O. persica extract at the dosage of 200 mg/kg reversed all these parameters to the control level. Marrow area/cortical area in rats treated with 450 mg/kg O. persica extract were highest among groups. No significant difference observed in osteoid thickness among different groups. Although the ash weights of both compact and cancellous bones in STZ group had no significant difference with control, ash weight of L4 vertebrate in rats treated with 300 and 450 mg/kg of extract was significantly lower than other groups. In conclusion, ethanolic extract of O. persica has bone protective effects in STZ-treated rats irrespective to its glucose lowering properties.