Alpha-hederin induces the apoptosis of oral cancer SCC-25 cells by regulating PI3K/Akt/mTOR signaling pathway

ABSTRACT

BACKGROUND: Oral cancer is one of the common malignant tumors of the head and neck. However, current treatments have numerous side effects, and drugs from natural sources may have better therapeutic potential. This research investigated the induction of apoptosis by α-hederin (α-HN), a constituent of Pulsatilla chinensis (Bunge) Regel, in the oral cancer cell line SCC-25 and its underlying mechanism. RESULTS: SCC-25 cells were treated with 50, 100, and 200 µmol/L α-HN. Cell proliferation; extent of apoptosis; activities of caspases-3, 8, and 9; and the expression of Bcl-2, Bax, phosphorylated (p)-phosphoinositide 3-kinase (PI3K), p-Akt, and p-mammalian target of rapamycin (mTOR) proteins were determined using the 3-(4,5)-2-thiazole-(2,5)-diphenyl tetrazolium bromide, flow cytometry, caspase activity detection kits, and western blot assays, respectively. The results showed that the proliferation of SCC-25 cells in the α-HN-treated groups decreased significantly, and the inhibitory effect was time and concentration dependent. Compared with cells in the control group, the extent of apoptosis increased significantly, caspase-3 and -9 activities were significantly enhanced, and the Bcl-2 level was lowered and the Bax level was elevated significantly in SCC-25 cells treated with α-HN for 48 h (P b 0.05). The expression of p-PI3K, p-Akt, and p-mTOR was also significantly lower in SCC-25 cells treated with α-HN than that in the control group (P b 0.05). CONCLUSION: These results indicate that α-HN can inhibit proliferation and induce apoptosis of SCC-25 cells and may exert these effects by inhibiting the PI3K/Akt/mTOR signaling pathway.