Effects And Mechanism Of Gengnianchun Formula On Skin Aging In Ovariectomized SD Rats

After the onset of menopause,skin aging signs such as wrinkles,dryness, decreased elasticity and so on appear to be more obvious due to ovarian hormone deficiency.With the aging of world population and the rising of economical level,not only reducing the rate of postmenopausal bone loss but also delaying the progress of skin aging has become people's great interest.It has been revealed that estrogen replacement therapy(ERT) could delay skin aging.Unfortunately,ERT may be accompanied by the possibility of cancer accidence. ERT is therefore recommended only for women who have no contraindications.So far, using estrogen to delay the skin aging is not considered the common therapy in clinic.Traditional medicine,however,stand out for its good action on climacteric syndrome.Gengnianchun formula(GNC) was proved effective in treating climacteric syndrome in women.The prophylactic action of GNC on osteoporosis and Alzheimer disease in ovariectomy(OVX) SD rats has been confirmed.The present study was designed to study the possible effects of GNC on skin aging in OVX SD rats and to investigate the mechanism of the effects.1.Effects of GNC on skin aging in OVX SD ratsObjects:To study the possible effects of GNC on skin aging in OVX SD rats.Methods:Five groups of ten to twelve months old SD rats were used.Four of them were ovariectomized bilaterally.2 weeks later,they were fed with different concentrations of GNC:high(H group) and low level(L group),nilestriol(E group) and saline(N group) for 3 months,respectively.The other one group had been fed with saline(S group) for 3 months,but without been ovariectomized.Skin tissue of the back area were ectomied for histological study and measurement of hydroxyproline(HYP),superoxide dismutase(SOD) and maleic dialdehyde(MDA).The Realtime PCR was performed to compare the expression of epidermal growth factor receptor(EGFR),matrix metalloproteinases-1(MMP-1) and matrix metalloproteinases-3(MMP-3) mRNA of skin tissue.Results:After treated with GNC or nilestriol,the amount of HYP and the activity of SOD were significantly increased while the amount of MDA was significantly reduced.The mRNA level of EGFR of skin tissue all increased dramatically in GNC and E group.But there was no significant change in MMP-1 and MMP-3 mRNA level after treated with GNC or nilestriol.Conclusions:Our study shows GNC can increase the content of collagen of the OVX SD rats.It suggests that the synthesis of collagen increased after treated with GNC.While the function of GNC in collagen degradation needs the further study. Meanwhile,the fact is proved that GNC improve the oxidation defense of the OVX SD rats.2.Mechanism of GNC on skin aging in OVX SD ratsObjects:To investigate the mechanism of GNC on skin aging in OVX SD rats.Methods:Blood samples and skin tissue of the back area in the H group,L group, E group,N group and S group were obtained immediately after the rats were killed. Blood samples were collected for estradiol level determination.The dorsal skin tissue were used for realtime PCR to compare the expression of ERαand ERβ. Immunohistochemical study was performed to show the localization of ERαand ERβin the skin of OVX SD rats.Results:The serum estradiol level did not significant increase after treated with GNC.The localization of ERαand ERβin the skin of OVX SD rats is shown.The mRNA level of ERαand ERβof skin tissue increased dramatically after treated with GNC.Conclusions:The mechanism of GNC on Skin Aging may be associated with the improvement of the expression of ER subtype of skin tissue but not with the improvement of the level of serum estradiol.