Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand.
Food Chem Toxicol. 2010 Aug-Sep;48(8-9):2122-9. doi: 10.1016/j.fct.2010.05.014. Epub 2010 May 25.
The aim of this study was to evaluate antioxidant activity and cytotoxicity against human cell lines of fruit peel extracts from rambutan, mangosteen and coconut. The highest antioxidant activity was found from rambutan peel crude extract where the highest radical scavenging capacity via ABTS assay was from its ethyl acetate fraction with a TEAC value of 23.0mM/mg and the highest ferric ion reduction activity via FRAP assay was from its methanol fraction with an EC value of 20.2mM/mg. Importantly, using both assays, these fractions had a higher antioxidant activity than butylated hydroxyl toluene and vitamin E. It was shown that the ethyl acetate fraction of rambutan peel had the highest polyphenolic content with a gallic acid equivalent of 2.3mg/mL. The results indicate that the polyphenolic compounds are responsible for the observed antioxidant activity of the extracts. Interestingly, the hexane fraction of coconut peel showed a potent cytotoxic effect on KB cell line by MTT assay (IC(50)=7.7 microg/mL), and no detectable cytotoxicity toward normal cells. We concluded that the ethyl acetate fraction of rambutan peel is a promising resource for potential novel antioxidant agents whereas the hexane fraction of coconut peel may contain novel anticancer compounds.
本研究旨在评估红毛丹、山竹和椰子果皮提取物的抗氧化活性和对人细胞系的细胞毒性。红毛丹果皮粗提取物具有最高的抗氧化活性，通过 ABTS 测定法，其乙酸乙酯部分的自由基清除能力最高，TEAC 值为 23.0mM/mg；通过 FRAP 测定法，其甲醇部分的铁离子还原活性最高，EC 值为 20.2mM/mg。重要的是，这两个测定法的结果都表明，这些部分的抗氧化活性高于丁羟甲苯和维生素 E。结果表明，红毛丹果皮的乙酸乙酯部分具有最高的多酚含量，相当于没食子酸 2.3mg/mL。结果表明，多酚化合物是提取物表现出抗氧化活性的原因。有趣的是，椰子果皮的正己烷部分通过 MTT 测定法对 KB 细胞系表现出强烈的细胞毒性（IC（50）=7.7μg/mL），而对正常细胞没有检测到细胞毒性。我们得出结论，红毛丹果皮的乙酸乙酯部分是有前途的新型抗氧化剂资源，而椰子果皮的正己烷部分可能含有新型抗癌化合物。
