Antiosteoporotic activity of phytoestrogen-rich fraction separated from ethanol extract of aerial parts of Cissus quadrangularis in ovariectomized rats

Objective: Cissus quadrangularis L. (C. quadrangularis L.) (Vitaceae) has been reported in Ayurveda for its antiosteoporotic activity. The study separated the phytoestrogen-rich fraction (IND-HE) from aerial parts of C. quadrangularis L. and evaluated its effect on osteoporosis caused by ovariectomy in rats. Materials and Methods: IND-HE was separated from the ethanol extract of C. quadrangularis. Ovariectomized female Wistar rats were divided into four groups (n = 6). Group 1: Control (distilled water), Group II: IND-HE (75 mg/kg p.o.), Group III: IND-HE (100 mg/kg p.o.) were treated once daily for 8 weeks and Group IV: standard estradiol group, received estrogen (1 mg/kg, s.c. bi-weekly). The effects on body weight were determined. DEXA (Dual energy-emission X-ray absorptimatory analysis) of whole body bone and femur was carried out. Blood was removed and analyzed for biochemical parameters. After sacrificing the animals, biomechanical study of right tibia and histopathology of pelvic bone was carried out. Results: IND-HE showed presence of phytoestrogen-rich fraction. IND-HE (75 and 100 mg/kg) and estrogen treatment showed statistically significant increase in bone thickness, bone density and bone hardness. IND-HE (75 and 100 mg/kg) and estrogen treatment significantly increased serum estradiol. IND-HE (100 mg/kg) (P<0.05) and estrogen treatment increased serum vitamin D3 and serum calcium compared to control. Alkaline phosphatase was significantly reduced by IND-HE (100 mg/kg p.o.) and estrogen treatment. Histopathology and DEXA results indicated that IND-HE (75 and 100 mg/kg) prevented bone loss. Discussion and Conclusion: These findings confirm that phytoestrogen-rich fraction (IND-HE) possess good antiosteoporotic activity.