Impacts of You Gui Wan on the expression of estrogen receptors and angiogenic factors in OVX-rat vagina: A possible mechanism for the trophic effect of the formula on OVX-induced vaginal atrophy

Abstract

The administration of You Gui Wan (YGW) decoction has been observed to improve vaginal atrophy induced by ovariectomy (OVX) in rats. The aim of the current study was to explore the possible mechanisms underlying this effect. Following OVX, 37 Sprague Dawley female rats were randomly divided into three groups which were orally administered with YGW decoction, saline or estrogen for 11 weeks. In parallel with this, 19 normal and 17 rats with sham-surgery were used as controls. The effects of these treatments on estrogen receptors (ER) and various angiogenic factors, including vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-1 (VEGFR-1), angiopoietin (Ang)1 and 2 and basic fibroblast growth factor (bFGF) in the vagina were compared using immunohistochemistry or quantitative polymerase chain reaction (qPCR). OVX was found to induce significant vaginal atrophy and decrease the expression of ER and various angiogenic factors when compared with the normal and sham-surgery animals (all P<0.05). Estrogen replacement and the administration of YGW decoction reversed the vaginal atrophic process. The hormonal replacement and YGW treatment recovered the protein expression of ER-α and -β, VEGF and VEGFR-1 and the mRNA levels of ER-α, VEGF, VEGFR-1, Ang1 and 2, and bFGF when compared with OVX-rats with saline, normal and sham-surgery treatments (all P<0.05). Thus, it may be concluded that a possible mechanism underlying the effect of YGW on OVX-induced vaginal atrophy may be the upregulated expression of ER and various angiogenic factors in the vaginal tissue.