School of Medicine, Fu Jen University, Taipei, Taiwan.
Nutrition. 2012 Jan;28(1):98-105. doi: 10.1016/j.nut.2011.05.009. Epub 2011 Aug 6.
Zizyphus jujuba, a traditional Chinese herb rich in functional components such as polysaccharide, has been widely consumed in Asian countries. The objective of this study was to determine the antiproliferation effect of melanoma cells as affected by deproteinized polysaccharide (DPP) isolated from Z. jujuba.
Deproteinized polysaccharide was obtained through boiling water extraction, ethanol precipitation, deproteinization, and dialysis, and the molecular weight of DPP was determined by high-performance gel-filtration chromatography. Melanoma cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the cell cycle was analyzed by flow cytometry, the formation of apoptotic bodies was observed under a fluorescence microscope at 450 nm, and caspase-3 and caspase-9 were measured by an assay kit.
Deproteinized polysaccharide was composed of two fractions with average molecular weights of 143 108 and 67 633 Da. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test showed that the antiproliferation effect of DPP on melanoma cells followed a dose- and time-dependent course. The 50% inhibitory concentration of DPP in inhibiting melanoma cell growth was 3.99 ± 0.10 mg/mL after 24-h treatment but decreased significantly to 3.36 ± 0.14 mg/mL after 48 h. The cell cycle assay revealed melanoma cells to be arrested in G2/M phase. Moreover, with DPP treatment, the apoptotic bodies were generated, accompanied by an increase in caspase-3 and caspase-9 activity.
This outcome suggested that DPP may be used as a potential anti-skin cancer agent for further in vivo and clinical trial experiments.
酸枣是一种传统的中草药，富含多糖等功能性成分，在亚洲国家被广泛食用。本研究旨在确定从酸枣中提取的去蛋白多糖（DPP）对黑素瘤细胞增殖的抑制作用。
通过水煮提取、乙醇沉淀、去蛋白和透析获得去蛋白多糖，并用高效凝胶过滤色谱法测定 DPP 的分子量。通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）比色法测定黑素瘤细胞活力，用流式细胞术分析细胞周期，在荧光显微镜下观察 450nm 下凋亡小体的形成，用试剂盒测定半胱天冬酶-3 和半胱天冬酶-9。
去蛋白多糖由两个平均分子量分别为 143108 和 67633Da 的级分组成。MTT 试验表明，DPP 对黑素瘤细胞的增殖抑制作用呈剂量和时间依赖性。DPP 抑制黑素瘤细胞生长的 50%抑制浓度（IC50）在 24 小时处理后为 3.99±0.10mg/mL，但在 48 小时后显著降低至 3.36±0.14mg/mL。细胞周期试验表明黑素瘤细胞被阻滞在 G2/M 期。此外，随着 DPP 的处理，凋亡小体产生，同时半胱天冬酶-3 和半胱天冬酶-9 的活性增加。
该结果表明，DPP 可作为一种潜在的抗皮肤癌药物，用于进一步的体内和临床试验。
