[Effect of ginsenoside Rg_1 in delaying premature ovarian failure induced by D-gal in mice through PI3K/Akt/mTOR autophagy pathway]

The aim of this paper was to study the role of phosphoinositide 3-kinase(PI3 K), protein kinase B(Akt) and mamma-lian target of rapamycin(mTOR) in the inhibition of premature ovarian failure induced by D-galactose(D-gal) in mice model by ginsenoside Rg_1(Rg_1). Fifty-four female SPF BALB/c mice were randomly divided into PBS group, D-gal group, and Rg_1 group. In the D-gal group, D-galactose(200 mg·kg~(-1)·d~(-1)) was injected subcutaneously into the neck and back for 42 days. In the PBS group, an equal amount of phosphate buffered saline(PBS) was injected into the neck and back for 42 days. In addition to the therapy of D-gal group, Rg_1 group was given Rg_1(20 mg·kg~(-1)·d~(-1)) through intraperitoneal injection since the 15 th day for 28 days, at the same time, the D-gal group and the PBS group were also given an equal amount of PBS through intraperitoneal injection since the 15 th day for 28 days. After the treatment, the estrous cycle changes of the mice were detected, and the ovarian SA-β-Gal staining was used to detect the changes of ovarian aging. Western blot was used to detect the changes in protein expressions of PI3 K, Akt, mTOR, S6 k, LC3-Ⅱ and P16~(INK4 a). Fluorescence quantitative PCR was used to detect the changes in mRNA expressions of PI3 K, Akt, mTOR, S6 k, LC3-Ⅱ and P16~(INK4 a). According to the findings, compared with the PBS group, the D-gal group began to show estrous cycle disorder in the 3 rd week,the ovarian SA-β-Gal staining positive granulosa cells increased in the D-gal group, the expression of senescence marker P16~(INK4 a) increased, while the expression of autophagy signaling molecule LC3-Ⅱ decreased. After treatment with Rg_1, the positive rate of ovarian SA-β-Gal staining in Rg_1 group decreased, the expression level of autophagy signaling molecule LC3-Ⅱ in Rg_1 group was higher than that in D-gal group, while the expression level of senescence marker P16~(INK4 a) was lower than that in D-gal group. Compared with the PBS group, the protein and mRNA expressions of PI3 K, Akt, mTOR and S6 k in the D-gal group were up-regulated, the protein expressions of Akt, mTOR and S6 k in the Rg_1 group were up-regulated, and the mRNA expressions of PI3 K and mTOR were up-regulated. After treatment with Rg_1, the protein expressions of PI3 K, Akt, mTOR and S6 k in the Rg_1 group were lower than those in the D-gal group, while the mRNA expressions of Akt, mTOR and S6 k in the Rg_1 group were lower than those in the D-gal group. The finding ssuggested that Rg_1 has the effect in delaying ovarian premature failure in D-gal-induced mouse models, and PI3 K/Akt/mTOR autophagy signaling pathways play an important role.