C21 steroidal glycosides have been extensively reported for treating several types of cancer and are widely found in Marsdenia tenacissima. In this study, a C21 fraction was synthesized from M. tenacissima, and its anti-cancer potency was assessed against in vitro gastric cell lines BGC-823, SGC-7901, and AGS. Significant growth inhibition and cell cycle arrest were observed in C21 fraction-treated gastric cancer cells. The results of apoptotic staining techniques in C21 fraction-treated gastric cells were confirmed with excess reactive oxygen species generation. Moreover, SOD and H₂O₂ levels were increased by C21 fraction, especially when combined with chloroquine (CQ). The apoptotic inducing potential of C21 fraction was also evidenced by upregulation of proapoptotic proteins cleaved-PARP and BAX and downregulation of antiapoptotic proteins Bcl-2 and p-AKT by western blot, especially in the presence of the autophagy inhibitor CQ. The results showed that the apoptosis of gastric cancer cells caused by C21 fraction was enhanced by inhibiting autophagy. The current findings reveal a new mechanism for the antitumor activity of C21 fraction on gastric cancer.

中文翻译：

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通过抑制人类胃癌细胞系中的自噬，增强了由马氏den虫诱导的细胞凋亡提炼的C21馏分

C21类固醇糖苷已被广泛报道用于治疗多种类型的癌症，并在马氏小球藻中广泛发现。在这项研究中，从藤蔓分枝杆菌合成了C21馏分，并评估了其对体外胃癌细胞系BGC-823，SGC-7901和AGS的抗癌能力。在用C21分数处理的胃癌细胞中观察到了显着的生长抑制和细胞周期停滞。用过量的活性氧产生，证实了在C21馏分处理的胃细胞中凋亡染色技术的结果。此外，SOD和H ₂ O ₂C21分数增加了血药浓度，尤其是与氯喹（CQ）结合使用时。还通过蛋白质印迹法特别是在存在自噬抑制剂CQ的情况下，通过上调裂解的PARP和BAX的促凋亡蛋白和下调抗凋亡蛋白的Bcl-2和p-AKT来证明C21组分的凋亡诱导潜力。结果表明，抑制自噬可增强C21组分引起的胃癌细胞凋亡。目前的发现揭示了C21级分对胃癌的抗肿瘤活性的新机制。