Protective effect of the olive hydroalcoholic extract on estrogen deficiency-induced bone loss in rats in comparison with estradiol

Osteoporosis, as a skeletal disorder caused by aging, is considered a major health problem. This work was planned to assess the effect of the black olive hydroalcoholic extract on bone mineral density and biochemical parameters in ovariectomized rats.

Ninety 6-month-old female Sprague Dawley rats were randomly assigned into 7 sets: control (received saline); sham-operated control, Ovariectomized (OVX) rats (received saline); 3 groups of black olive-supplemented OVX rats (respectively, receiving 250, 500, and 750 mg/kg body wt black olive extract orally); and estrogen group (receiving 3 mg/kg/day estradiol valerate). Blood samples were collected 2, 4 and 6 months after treatment to measure calcium (Ca), alkaline phosphatase (ALP), and phosphorus (P). Dual-energy X-ray absorptiometry (DEXA) was applied to measure the bone mineral density (BMD). Global, lumbar spine and lower limb BMD was measured.

Ca concentration was significantly increased in the group treated with the highest dose of black olive hydroalcoholic compared to the OVX group (p <0.001). In addition, a significant decrease in ALP concentrations in the group treated with the highest dose of black olive hydroalcoholic comparing with the OVX group was observed (p <0.001). The global, tibia, femur and spine BMD in the group treated with the highest dose of black olive hydroalcoholic and estrogen group were significantly increased compared to the OVX group (p <0.05).

Black olive hydroalcoholic extract at the dose of 750 mg/kg, prevented bone loss and augmented bone mineral density and could be a possible candidate for the management of osteoporosis.