Background: 

The effects of estrogen deprivation observed in menopausal women result in deep modifications of skin including wrinkling, dryness, atrophy, laxity, poor wound healing, hot flushes and vulvar atrophy. Genistein, a soy-derived isoflavone, has been tested in anti-aging cosmetic preparations with interesting results on skin elasticity, photoaging and skin cancer prevention.

Aim: 

We investigated the effects of genistein aglycone compared with systemic raloxifene hydrochloride and 17-alpha-ethinylestradiol on skin aging and wound healing in ovariectomized (OVX) rats.

Methods: 

Six months after ovariectomy, rats were randomized and treated, daily, with genistein aglycone (1 and 10 mg/kg/s.c.) or raloxifene hydrochloride (0.05 and 0.5 mg/kg/s.c.) or 17-alpha-ethinylestradiol (0.003 and 0.03 mg/kg/s.c.) for 12 weeks. Controls were untreated OVX and sham OVX rats. At the end of treatment, skin biopsy and skin incision were carried out and skin samples were tested for molecular, functional and histological measurements.

Results: 

OVX rats showed a decrease in TGF-beta1, VEGF, MMP-2, MMP-9 and TIMP/MMP ratio compared to sham OVX (p<0.001). All treatments significantly modified the depressed molecular profile revealed in OVX rats. Genistein aglycone at the dose of 1 mg/kg also increased the thickness of sub-epithelial layer and collagen fibers in reticular dermis (p<0.001). Moreover, the lowest dose of genistein was the most effective in improving skin tensile strength.

Conclusions: 

The present results strongly suggest that genistein aglycone, a soy-derived isoflavone, improving the physiological remodeling of extracellular matrix and mechanical properties of skin, might be a reliable alternative therapy for the management of skin health in postmenopausal women.