S-allylmercaptocysteine suppresses the growth of human gastric cancer xenografts through induction of apoptosis and regulation of MAPK and PI3K/Akt signaling pathways

Gastric cancer remains as a common lethal malignancy worldwide. Developing novel anti-gastric cancer drugs with minimal side effects is necessary to address this public health issue. S-allylmercaptocysteine (SAMC), one of the water-soluble organosulfur garlic derivatives, has been demonstrated as a suppressive agent against tumors. In this study, we examined the effect of SAMC on human gastric carcinoma growth in vivo and explored the underlying mechanism. Human gastric cancer SGC-7901 cells were inoculated subcutaneously in BALB/c nude mice. When xenograft tumors reached about 100 mm3, mice were treated with SAMC for 30 days. We observed that SAMC administration in mice effectively delayed the growth of SGC-7901 xenografts without signs of toxicity. TUNEL staining confirmed that the tumors from SAMC-treated mice exhibited a markedly higher apoptotic index. Mechanistic studies suggested that this activity may arise from its effects on the caspase activation and modulation of MAPK and PI3K/Akt signaling pathways. Taken together, these data support development of SAMC as a potential agent for gastric cancer therapy.