Lipoic acid stimulates bone formation in ovariectomized rats in a dose-dependent manner

This study was undertaken to determine the osteotropic effect of different doses of lipoic acid (LA) on the mineralization of bone tissue in female Wistar rats with experimental osteopenia induced by bilateral ovariectomy. Fifty-six rats were randomly selected and submitted to either a sham operation (n = 8) or an ovariectomy (n = 48). The ovariectomized rats were randomly placed into two control groups, treated subcutaneously with either physiological saline or 17 beta-estradiol in the dose of 4 mu g/kg body mass per day, and four experimental groups that received LA subcutaneously in the doses of 12.5, 25, 50, and 100 mg/kg body mass per day (n = 8 in each group). After 28 days of experimental treatment, the rats were sacrificed, and body mass, total skeletal density, and body composition were recorded. Blood serum and isolated femora were stored for further analysis. Our results revealed that the osteoprotective effect of LA was dose-dependent and was observed in rats treated with 50 and 100 mg/kg of LA. Moreover, the LA applied to the ovariectomized rats in the dose of 50 mg/kg not only stopped the bone resorption, but stimulated its formation.