Samodien Sedicka, Kock Maryna de, Joubert Elizabeth, Swanevelder Sonja, Gelderblom Wentzel C A
Applied Microbial and Health Biotechnology Institute, Cape Peninsula University of Technology, Bellville, South Africa.
Department of Medical Bioscience Program, University of Western Cape, Bellville, South Africa.
Nutr Cancer. 2021;73(10):2050-2064. doi: 10.1080/01635581.2020.1820054. Epub 2020 Sep 15.
Differential anti-proliferative and pro-apoptotic effects of aqueous extracts of green rooibos (Rg; ) and green tea (GT; ) and an aspalathin-enriched extract of green rooibos (GRE), were investigated in primary rat hepatocytes (PH) and human liver (HepG2) and colon (HT-29) cancer cells. Rooibos flavonoids, aspalathin and luteolin, and the green tea flavanol, epigallocatechin gallate (EGCG), were included to assess their contribution relative to their extract concentrations. GRE was the most effective in reducing cell growth parameters which was associated with a high total polyphenol content and high ferric reducing potential. Differential cell responses were noticed with HepG2 cells more sensitive than PH toward the induction of apoptosis by GRE. Luteolin induced apoptosis in PH and HepG2 cells while aspalathin lacked any effect. EGCG induced apoptosis in HepG2 cells while PH were resistant. HT-29 cells were resistant to apoptosis induction by the tea and pure flavonoids. Differences existed in the individual effects of the major rooibos and GT flavonoids against cell growth parameters compared to their equivalent concentrations in the extract mixtures. Diversity of the flavonoid constituents, physicochemical properties and cellular redox status governing cell survival are likely to explain the differential cell responses.
研究了南非博士茶（Rg）和绿茶（GT）的水提取物以及富含阿萨伊拉辛的南非博士茶提取物（GRE）对原代大鼠肝细胞（PH）、人肝癌细胞（HepG2）和结肠癌细胞（HT-29）的不同抗增殖和促凋亡作用。纳入了南非博士茶黄酮类化合物、阿萨伊拉辛和木犀草素以及绿茶黄烷醇表没食子儿茶素没食子酸酯（EGCG），以评估它们相对于提取物浓度的贡献。GRE在降低细胞生长参数方面最有效，这与高总多酚含量和高铁还原能力有关。观察到不同的细胞反应，HepG2细胞比PH细胞对GRE诱导的凋亡更敏感。木犀草素在PH和HepG2细胞中诱导凋亡，而阿萨伊拉辛没有任何作用。EGCG在HepG2细胞中诱导凋亡，而PH细胞具有抗性。HT-29细胞对茶和纯黄酮类化合物诱导的凋亡具有抗性。与提取物混合物中同等浓度相比，主要南非博士茶和绿茶黄酮类化合物对细胞生长参数的个体作用存在差异。黄酮类成分的多样性、物理化学性质和控制细胞存活的细胞氧化还原状态可能解释了不同的细胞反应。
