核桃仁蛋白木瓜酶水解物抑制癌细胞增殖

Inhibition of proliferation induced by papain hydrolysate of walnut protein on cancer cells

用碱性蛋白酶、胰蛋白酶、胃蛋白酶、木瓜蛋白酶及中性蛋白酶制备5种核桃仁蛋白酶水解物,通过细胞增殖分析试验,研究核桃仁蛋白及其酶水解物对人乳腺癌细胞(MCF-7)增殖的影响。结果表明,核桃仁蛋白木瓜酶水解物具有明显的抑制细胞生长作用(IC50值为1.62 mg/mL),而核桃仁蛋白及其他4种蛋白酶水解物没有显示明显的抑制细胞生长作用。核桃仁蛋白木瓜酶水解物对人结肠癌细胞(Caco-2)及人宫颈癌细胞(Hela)也具有明显的抑制生长作用(IC50值分别为2.04、2.21 mg/mL)。然而,核桃仁蛋白木瓜酶水解物对非肿瘤细胞大鼠小肠隐窝上皮细胞(IEC-6)未显示明显的抑制生长作用,对小鼠脾淋巴细胞还具有一定促进增殖作用。以上结果表明,核桃仁蛋白中含有抑制癌细胞增殖的活性肽,当核桃仁蛋白被木瓜酶水解后该活性肽显示出明显的生物活性作用。

Walnut protein hydrolyzates were prepared with alkaline protease, trypsin, pepsin, papain and neutral protease. The effect of walnut protein and walnut protein hydrolyzates on proliferation of human breast cancer cell （MCF-7） was studied by cell proliferation assay. The results indicated that the walnut protein hydrolyzed by papain inhibited significantly proliferation of the cells （IC50 value was 1.62 mg/mL）, while walnut protein and the protein hydrolyzates by other four proteases exhibited no obvious inhibitory effect. The papain hydrolysate of walnut protein also inhibited significantly proliferation of human colon carcinoma cell （Caco-2, IC50 value was 2.04 mg/mL）, and human cervical carcinoma cell （Hela, IC50 value was 2.21 mg/mL）. However, the papain hydrolysate of walnut protein did not show inhibitory effect on the growth of rat small intestinal crypt epithelial cell （IEC-6）, and promoted proliferation of spleen lymphocytes from mouse. These results suggest that bioactive peptides with inhibitory effect on proliferation of cancer cell were contained in walnut protein, and the biological activity was exhibited when the walnut protein was hydrolyzed by papain.