In this study, the anticancer effects of Porphyra haitanensis polysaccharides (PHPs) on human colon cancer cells and non-cancerous cells were evaluated. PHP was extracted by an ultrasonic/microwave-assisted method, and three fractions of polysaccharides (PHP-F1, PHP-F2 and PHP-F3) were obtained through a DEAE-52 cellulose ion-exchange column. The results of the cytotoxicity test showed that all of the PHP fractions had inhibitory effects on the growth of colon cancer cells HT-29, LoVo and SW-480, but no toxic effects on the normal human cells HaCaT. The fractions PHP-F2 and PHP-F3 had the most significant cytotoxicity on HT-29 cells. Studies on intracellular reactive oxygen species (ROS) levels, cell apoptosis, the apoptosis index (using Hoechst 33342 staining) and analysis of cell cycle arrest using flow cytometry revealed that the fractions PHP-F2 and PHP-F3 could apparently induce oxidative stress and apoptosis in HT-29 cells and cause cell G0–G1 phase arrest. These findings suggest that polysaccharides from P. haitanensis have anticancer effects on human colon cancer cells and therefore might be regarded as new candidates for the prevention and treatment of colon cancers.

在本研究中，紫菜的抗癌作用对人结肠癌细胞和非癌细胞上的多糖 (PHP) 进行了评估。采用超声波/微波辅助法提取PHP，通过DEAE-52纤维素离子交换柱得到3个多糖组分（PHP-F1、PHP-F2和PHP-F3）。细胞毒性试验结果表明，所有PHP组分均对结肠癌细胞HT-29、LoVo和SW-480的生长有抑制作用，但对正常人细胞HaCaT无毒性作用。PHP-F2和PHP-F3级分对HT-29细胞具有最显着的细胞毒性。研究细胞内活性氧 (ROS) 水平、细胞凋亡、细胞凋亡指数（使用 Hoechst 33342 染色）和使用流式细胞术的细胞周期停滞分析表明，PHP-F2 和 PHP-F3 组分可以明显诱导 HT-29 细胞的氧化应激和细胞凋亡，并导致细胞 G0-G1 期停滞。这些发现表明多糖来自P. haitanensis对人结肠癌细胞具有抗癌作用，因此可能被视为预防和治疗结肠癌的新候选物。