S-Allylmercaptocysteine (CySSA) from garlic and its onion analog S-1-propenylmercaptocysteine (CySSPe) show potential anti-cancer abilities. In this study, apoptosis induction by these two S-alk(en)lymercaptocysteine (CySSR) analogs in combination with Na₂SeO₃ (Se) was investigated in MDA-MD-231 breast cancer cells. CySSA and CySSPe alone did not affect cell viability, whereas CySSPe + Se and CySSA + Se showed dose-dependent reduction in cell viability. Synergistic effect was confirmed by isobologram analysis. Annexin-V staining and flow cytometric analysis revealed induction of apoptosis. Mechanistically, CySSR + Se upregulated GSK-3α/β and activated p53 to trigger apoptosis. Both CySSR + Se activated JNK pathway at an early stage, but only CySSPe + Se exhibited sustained JNK activation. Inhibition of the cystine/glutamate (x_C-) antiporter by sulfasalazine attenuated the antiproliferative effects of CySSR + Se suggesting the involvement of x_C- in CySSR + Se⁻ induced apoptosis. This study indicates that the onion analogue CySSPe was similarly as effective as the major studied garlic analogue CySSA in apoptosis induction in ER⁻ breast cancer cells.

大蒜中的S-烯丙基巯基半胱氨酸（CySSA）及其洋葱类似物S -1-丙烯基巯基半胱氨酸（CySSPe）具有潜在的抗癌能力。在这项研究中，这两个S- alk（en）巯基半胱氨酸（CySSR）类似物与Na ₂ SeO ₃组合诱导细胞凋亡（Se）在MDA-MD-231乳腺癌细胞中进行了研究。单独的CySSA和CySSPe不会影响细胞活力，而CySSPe + Se和CySSA + Se则显示出剂量依赖性的细胞活力降低。通过等效线图分析证实了协同作用。Annexin-V染色和流式细胞仪分析表明诱导凋亡。从机制上讲，CySSR + Se上调GSK-3α/β并激活p53触发凋亡。CySSR + Se都在早期激活了JNK通路，但只有CySSPe + Se表现出持续的JNK激活。胱氨酸/谷氨酸的抑制（X _Ç - ）通过逆向转运柳氮衰减CySSR +硒提示x的参与抗增殖作用_Ç -在CySSR +硒^-诱导凋亡。这项研究表明，洋葱模拟CySSPe也同样有效，因为在ER主要研究的大蒜模拟CySSA诱导细胞凋亡^-乳腺癌细胞。