Metabolic effects of 20-OH-Ecdysone in ovariectomized rats

Postmenopausal women develop often obesity which may be prevented by 20-OH-Ecdysone (Ecd). This was investigated in ovariectomized (ovx) rats. They were orally treated with 3 doses of Ecd (18, 56 or 116 mg/day/animal). Positive controls received 159 μg estradiol (E2). Quantitative computer tomography at the level of the abdomen and the metaphysis of the tibia allowed estimation of surface, fat depots and muscles. The highest dose of Ecd resulted in serum concentrations of 0.4 × 10−6 M. Serum E2 concentrations in the positive controls were 73.3 ± 24.41 pg/ml. E2 but not Ecd stimulated uterine weights. Under Ecd ovx animals gained less fat but had more muscle mass. Serum TSH, T4 and T3 levels remained unaffected while E2 treatment increases T4 but decreases T3 levels. Ecd at the lowest dose lowered serum LDL and did not result in increased serum triglycerides, an effect seen in the E2 treated rats. At the Ecd highest dose serum HDL was higher than in the controls.In conclusion Ecd has beneficial effects on fat and muscle tissue and may be able to prevent the metabolic syndrome and sarcopenia by a non-estrogenic mechanism.