Magcwebeba Tandeka Unathi, Riedel Sylvia, Swanevelder Sonja, Swart Pieter, De Beer Dalene, Joubert Elizabeth, Andreas Gelderblom Wentzel Christoffel
Department of Biochemistry, Stellenbosch University, Stellenbosch, South Africa.
Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg, South Africa.
J Pharm Pharmacol. 2016 Nov;68(11):1440-1453. doi: 10.1111/jphp.12629. Epub 2016 Sep 27.
The relationship between polyphenol constituents, antioxidant properties of aqueous and methanol extracts of green tea (Camellia sinensis), the herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.), against skin cell viability was investigated in vitro.
The effect of extracts, characterised in terms of polyphenol content and antioxidant properties, on cell viability of premalignant, normal and malignant skin cells was determined.
Phenolic composition, particularly high levels of potent antioxidants, of rooibos and green tea methanol extracts was associated with a strong reduction in cell viability specifically targeting premalignant cells. In contrast, the aqueous extracts of Cyclopia spp. were more effective in reducing cell viability. This correlated with a relatively high flavanol/proanthocyanidin content and ABTS radical cation scavenging capacity. The major green tea flavanol (epigallocatechin gallate) and rooibos dihydrochalcone (aspalathin) exhibited differential effects against cell viability, while the major honeybush xanthone (mangiferin) and flavanone (hesperidin) lacked any effect presumably due to a cytoprotective effect. The underlying mechanisms against skin cell viability are likely to involve mitochondrial dysfunction resulting from polyphenol-iron interactions.
The polyphenol constituents and antioxidant parameters of herbal tea extracts are useful tools to predict their activity against skin cell survival in vitro and potential chemopreventive effects in vivo.
研究绿茶（茶树）、草本茶、路易波士茶（线叶金雀花）和蜜树茶（Cyclopia属）水提取物和甲醇提取物中的多酚成分与抗氧化特性对皮肤细胞活力的体外关系。
测定了根据多酚含量和抗氧化特性表征的提取物对癌前、正常和恶性皮肤细胞活力的影响。
路易波士茶和绿茶甲醇提取物的酚类成分，特别是高水平的强效抗氧化剂，与细胞活力的显著降低有关，这种降低特别针对癌前细胞。相比之下，蜜树茶水提取物在降低细胞活力方面更有效。这与相对较高的黄烷醇/原花青素含量和ABTS自由基阳离子清除能力相关。主要的绿茶黄烷醇（表没食子儿茶素没食子酸酯）和路易波士茶二氢查耳酮（南非茶黄素）对细胞活力表现出不同的影响，而主要的蜜树茶氧杂蒽酮（芒果苷）和黄烷酮（橙皮苷）可能由于细胞保护作用而没有任何影响。针对皮肤细胞活力的潜在机制可能涉及多酚-铁相互作用导致的线粒体功能障碍。
草本茶提取物的多酚成分和抗氧化参数是预测其体外对皮肤细胞存活的活性以及体内潜在化学预防作用的有用工具。
