The effect of alfalfa ethyl acetate extract on osteoporosis in ovariectomized rats

Considering alfalfa as a source of phytoestrogens, and the positive effect of phytoestrogens on bone, the aim of this study was to evaluate effect of the ethyl acetate extract of alfalfa on the osteoporosis induced by ovariectomy.

Thirty 3-Month-Old female Wistar rats were accidentally divided to 5 groups, including sham, ovariectomy (ovx), sham+4 (4g/kg extract in diet), ovx+2 (2g/kg extract in diet) and ovx+4 (4g/kg extract in diet). Two weeks after ovariectomy or sham operation rat received ethyl acetate extract of alfalfa for 75 days. Then, the levels of alkaline phosphatase, calcium and phosphorus in serum and femur, and magnesium and estrogen in serum were measured. Thigh bone mineral density and tissue changes were also compared in the study groups.

The amounts of calcium, phosphorus, magnesium and mineral density were not significantly different in the study groups. Estrogen concentration in ovx group was lower than the sham and the sham+4 groups. Among the experimental groups, rats in ovx group showed maximal activity of alkaline phosphatase in serum and the minimal activity in femur (p˂0.05). The bone density, thickness of spongy bone blade and diameter/ number of hoarse system decreased in ovx group. However, they were increased in ovx+2, ovx+4, and sham+4 groups.

It seems that the ethyl acetate extract of alfalfa decreases osteoporosis by modification of increase in the activity of serum alkaline phosphatase, and estrogen deficiency in ovariectomized rats.