The effects of 20-hydroxyecdysone and 17β-estradiol on the skin of ovariectomized rats

Objective: 20-hydroxyecdysone has numerous favorable effects on a variety of organs, including the skin, where it improves wound healing. It is devoid of estrogenic and androgenic effects. Therefore, application of 20-hydroxyecdysone might be a new approach to improve skin conditions in postmenopausal women, and this was investigated in ovariectomized (OVX) rats. Methods: After ovariectomy, rats received Ecd (18, 57, or 116 mg/animal/day) or 17 beta-estradiol (E-2)-3-benzoate (60 mu g/kg body weight) in food for 12 weeks, and skin samples were evaluated histologically to quantify two dermal layers, the subcutaneous fat and muscle layers. Results: Epidermal thickness was lowest in the OVX animals, slightly higher in the E-2-treated animals, and significantly higher in the Ecd-treated animals. Dermal thickness was lowest in the intact and E-2-treated animals and highest in the Ecd-treated animals. The subcutaneous fat layer was thickest in the OVX animals, thinner in the intact animals, and intermediate in the Ecd-treated animals. The muscle layer was smallest in the OVX and intact animals and significantly larger in the E-2- and Ecd-treated animals. The number of proliferating cell nuclear antigen antibodyYpositive cells was lowest in OVX controls and significantly higher in all other groups. Conclusions: The Ecd-induced increases in epidermal and dermal thickness are suggestive of functional changes of the skin. The decreased amounts of subcutaneous fat in the E-2- and Ecd-treated animals point to either a fat catabolic or an antianabolic effect. The ovariectomy-induced decrease in subcutaneous musculature was prevented by Ecd but not by E-2. The stimulatory effects of Ecd on epidermal and dermal thickness and the muscle-increasing effects in the skin of OVX rats may indicate functional changes of the skin.