[Active ingredients of Plastrum Testudinis inhibit epidermal stem cell apoptosis in serum-deprived culture].

Objective: To investigate the effects of active ingredients of Plastrum Testudinis (PT) on serum deprivation-induced apoptosis of epidermal stem cells (ESCs).

Methods: ESCs were isolated from the back skin of fetal Sprague-Dawley rats with 2 weeks of gestational age and were divided into normal group (10% fetal bovine serum), control group (serum-deprived culture) and groups treated with serum deprivation plus active ingredients of PT, including ethyl acetate extract (2B), stearic acid ethyl ester (S6), tetradecanoic acid sterol ester (S8) and (+)-4-cholesten-3-one (S9). The vitality of ESCs after 24, 48 and 72 h of culture was measured with MTT method; apoptotic ESCs double-stained with Annexin V-FITC and propidium iodine were detected by flow cytometry (FCM); Bcl-2 and caspase-3 expressions were measured by Western blotting.

Results: MTT results indicated that the vitality of ESCs in the active ingredients of PT groups at 48 h was increased compared with the control group and 2B had better effects than the others. FCM results indicated that 2B had the most significant anti-apoptotic effect compared with the control as well as S6, S8 and S9. Western blot results indicated that 2B, S6, S8 and S9 up-regulated the expression of Bcl-2 protein and down-regulated the expression of caspase-3 protein compared with the control.

Conclusion: Ethyl acetate extract of Plastrum Testudinis inhibits epidermal stem cell apoptosis in serum-deprived culture by regulating the expressions of Bcl-2 and caspase-3 proteins and has a stronger anti-apoptotic effect than its constituents S6, S8 and S9.