Recent advances in the anti-aging effects of phytoestrogens on collagen, water content, and oxidative stress.

Skin undergoes degenerative changes as it ages, which include the loss of elasticity, reductions in the epidermal thickness and collagen content, elastic fiber degeneration, and increased wrinkling and dryness. Skin aging can be significantly delayed by the administration of estrogen. Estrogen deficiency following menopause results in atrophic skin changes and the acceleration of skin aging. Estrogen administration has positive effects on human skin by delaying or preventing skin aging manifestations, but the use of estrogen replacement is a risk factor for breast and uterine cancer. Phytoestrogens are a large family of plant-derived molecules possessing various degrees of estrogen-like activity; they exhibit agonist or antagonist estrogenic properties depending on the tissue. These molecules could be ideal candidates to combat skin aging and other detrimental effects of hypoestrogenism. In this paper, we review the effects of phytoestrogens on human skin and the mechanisms by which phytoestrogens can alleviate the changes due to aging.

Underlying mechanism of Sirt1 on apoptosis and extracellular matrix degradation of osteoarthritis chondrocytes.

The study investigated the effects and underlying mechanisms of silent information regulation of transcription 1 (Sirt1) action on apoptosis in chondrocytes and degradation of the extracellular matrix. Cartilage tissue samples were derived from knee arthroplasty of patients with osteoarthritis (OA). The three groups were as follows: Control, resveratrol (Res) and Res+small interfering (si)RNA (Res+siRNA Sirt1). The level of Sirt1 protein expression significantly increased in the Res group (1.03±0.10) compared with the control (0.22±0.03) and Res+siRNA (0.18±0.01) groups (both P<0.05). Early and late stage cell apoptosis rates decreased in the Res group and increased in the Res+siRNA group (both P<0.05). B­cell lymphoma 2 (Bcl­2) expression levels were upregulated and Bcl­2­associated X protein (Bax) expression levels were downregulated in the Res group compared with the control group. Protein expression levels of MMP1 and MMP13 and the phosphorylation levels of extracellular signal regulated kinase (ERK), c­Jun N­terminal kinase (JNK) and p38 were downregulated in the Res group and upregulated in the Res+siRNA group. In conclusion, upregulation of Sirt1 expression may inhibit OA chondrocyte apoptosis and extracellular matrix degradation by increasing Bcl­2 expression and decreasing Bax, MMP1 and MMP13 expression, via downregulation of p38, JNK and ERK phosphorylation.