Edible green algal seaweeds, namely Ulva intestinalis and Ulva lactuca constitute a significant repository of popular herbal medicines in the Traditional Chinese Medicinal system. The present study aimed to assess the anticancer potential of these algal members and its mode of action in cervical cancer cells SiHa. The algal samples primarily extracted in methanol was fractionated into hexane, chloroform, and aqueous algal fractions, which inhibited the proliferation of SiHa cells in a dose-dependent manner, with the algal chloroform fractions harbouring the lowest IC₅₀ dose of 141.38 µg/ml in U. intestinalis and 445.278 µg/ml in U. lactuca. These algal chloroform fractions when studied for their in-depth mode of action, were found to damage and pulverise the nuclei, resulting in a concomitant increase in subG0-phase of SiHa cells, studied by flow cytometry. The algal treatment also caused an increase in the number of acidic vesicles and enhanced the expression of LC3BII, p62 and atg12 proteins, which together pointed out autophagy as the induced mode of cell death. Upregulated Bax and p53 expression along with decreased Bcl2 expression also correlated to autophagic cell death. Decreased expression of E6 viral oncogene was noted as a significant response to algal fractions. Lastly, these potent algal fractions when characterised pharmacologically through GC–MS analysis were found to be rich in unsaturated fatty acids, majorly palmitic acid. Hence, this study concludes that the two species of Ulva successfully decreased the proliferation of SiHa cervical cancer cells through autophagy, hinting at palmitic acid being the major responsible bioactive compound in both.

食用绿藻，即石莼和石莼，是中药体系中重要的常用草药宝库。本研究旨在评估这些藻类成员的抗癌潜力及其在宫颈癌细胞 SiHa 中的作用方式。主要在甲醇中提取的藻类样品被分成己烷、氯仿和水藻组分，其以剂量依赖性方式抑制SiHa细胞的增殖，其中藻氯仿组分具有最低IC 50 剂量，为141.38 _µg /ml。肠球菌和乳球菌中的含量为 445.278 µg/ml 。通过流式细胞术研究，当深入研究这些藻类氯仿组分的作用模式时，发现它们会破坏和粉碎细胞核，导致 SiHa 细胞的 subG0 相随之增加。藻类处理还导致酸性囊泡数量增加，并增强 LC3BII、p62 和 atg12 蛋白的表达，这些蛋白共同表明自噬是诱导细胞死亡的模式。Bax 和 p53 表达上调以及 Bcl2 表达降低也与自噬细胞死亡相关。E6 病毒癌基因表达的减少被认为是对藻类组分的显着反应。最后，通过 GC-MS 分析进行药理学表征时，发现这些有效的藻类组分富含不饱和脂肪酸，主要是棕榈酸。因此，本研究得出结论，两种石莼通过自噬成功降低了 SiHa 宫颈癌细胞的增殖，暗示棕榈酸是这两种石莼中主要的生物活性化合物。