Triptolide induces autophagy of ovarian granulosa cells via PI3K/AKT/m TOR pathway / 中国中药杂志

The aim of this paper was to observe the concentration,time and mechanism of autophagy induced by triptolide( TP) in ovarian granulosa cells( OGCs). CCK-8 method was used to compare the inhibitory effects of TP at different concentrations on primary cultured rat OGCs and IC50 was calculated. The effects of TP at different concentrations and time points on the expression of OGCs autophagy factor protein and the cascade of PI3 K/AKT/m TOR pathway were detected by Western blot. The effects of TP,autophagy inducer( brefeldin A) and PI3 K/m TOR inhibitor( NVP-BEZ235) on the expression of PI3 K/AKT/m TOR cascade and autophagy related factor protein were detected by Western blot. The results show that the IC50 of different concentrations of TP on OGCs of rat ovary was14. 65 μmol·L-1,and the minimum inhibitory concentration of TP was 0. 1 μmol·L-1( 100 nmol·L-1). Compared with the control group,the expression levels of beclin1 and LC3Ⅱ in each group were significantly higher than those in the control group( P<0. 05 or P<0. 01). After 12 hours of treatment with TP,brefeldin A and NVP-BEZ235,respectively,compared with the control group,TP could significantly promote the expression level of downstream autophagy effect or molecule beclin1,LC3Ⅱ and inhibit the expression level of LC3Ⅰ,p62 protein( P<0. 05 or P< 0. 01). Moreover,the expression of beclin1 and LC3Ⅱ/LC3Ⅰ in TP group was higher than that in brefeldin A group( P<0. 05 or P<0. 01),and the expression of p62 in TP group was lower than that in brefeldin A group( P<0. 05 or P<0. 01). At the same time,TP could significantly inhibit the expression of p-PI3 K,p-AKT,p-mTOR protein,and the inhibitory effect of TP was better than that of NVP-BEZ235 group. This study suggests that 100 nmol·L-1 TP could induce OGCs autophagy successfully in cultured rat ovary for 12 h; TP may induce OGCs autophagy by inhibiting PI3 k/Akt/m TOR signaling pathway.

Study of isobutyrylshikonin inhibiting proliferation of colon carcinoma cells through PI3K/Akt/m-TOR pathway / 中国中药杂志

To investigate the inhibitory effect of isobutyrylshikonin on the growth of human colon carcinoma cells and its effect on the PI3K/Akt/m-TOR pathway. MTT assay was used to detect the inhibitory effect of different concentrations (0, 6.25, 12.5, 25, 50, 100 mg·L⁻¹) of isobutyrylshikonin on the proliferation of human colon carcinoma cell HT29 at 24, 48 h. CCK-8 method was used to detect the inhibitory effect of isobutyrylshikonin on HT29, HCT116, DLD-1 and Caco-2 at 48 h. AnnexinV/propidium iodide staining was applied in detecting the apoptoticrate of HT29 cells treated with different concentrations of isobutyrylshikonin at 24 h and 48 h. Cycletest plus DNA was employed to analyze HT29 apoptosis and cell cycle after 48 h treatment with isobutyrylshikonin at different concentrations. Western blot and RT-PCR assay were used to examine the protein and mRNA expressions of PI3K, p-PI3K, Akt, p-Akt and m-TOR. The results showed that isobutyrylshikonin inhibited the proliferation of different human colon carcinoma cells, and the inhibition rate was in a dose-dependent manner. Isobutyrylshikonin induced apoptosis mainly in the early stage and blocked cells in the G₀/G₁ or G₂/M phase. Isobutyrylshikonin reduced the protein expressions of PI3K, p-PI3K, Akt, p-Akt, m-TOR and the mRNA expressions of PI3K, Akt, m-TOR in a dose-dependent manner. Isobutyrylshikonin can significantly inhibit the proliferation, induce the early apoptosis and change the cycle distribution in colon carcinoma cells.This biological effect may be correlated with the inhibition of PI3K/AKT/m-TOR pathway.