Rahmat Asmah, Kumar Vijay, Fong Loo Mei, Endrini Susi, Sani Huzaimah Abdullah
Department of Nutrition and Health Sciences, Faculty of Medicine and Health Sciences, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.
Asia Pac J Clin Nutr. 2003;12(3):292-5.
Antioxidants play an important role in inhibiting and scavenging radicals, thus providing protection to humans against infections and degenerative diseases. Literature shows that the antioxidant activity is high on herbal and vegetable plants. Realizing the fact, this research was carried out to determine total antioxidant activity and the potential anticancer properties in three types of selected local vegetable shoots such as Diplazium esculentum (paku shoot), Manihot utillissima (tapioca shoot) and Sauropous androgynus (cekur manis). The research was also done to determine the effect of boiling, on total antioxidant activity whereby samples of fresh shoots are compared with samples of boiled shoots. In every case, antioxidant activity is compared to alpha-tocopherol and two methods of extraction used are the organic and the aqueous methods. Besides that, two research methods used were the ferric thiocyanate (FTC) and thiobarbituric acid (TBA) with absorbance of 500 nm and 532 nm respectively. Oneway ANOVA test at P <0.05 determines significant differences between various samples. In the cytotoxic study, the ethanolic extract and several cell lines i.e. breast cancer (MDA-MB-231 and MCF-7), colon cancer (Caco-2), liver cancer (HepG2) and normal liver (Chang liver) were used. The IC50-value was determined by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The antioxidant study found that all the samples in both aqueous and organic extraction were significantly different. The total antioxidant activity values of aqueous extract in descending order are as follows : M. utilissima (fresh)> D. esculentum (fresh) > S.androgynus (fresh) > M.utilissima (boiled) > D. esculentum (boiled) > S.androgynus (boiled). It also was found that S.androgynus shoots ethanolic extract was able to inhibit the viability of the breast cancer cell lines, MDA-MB-231 with the IC subset 50 value of 53.33 microg/ml. However, S.androgynus shoots and D. esculentum shoots ethanolic extracts did not inhibit the viability of MDA-MB-231 cell line. While, the tapioca shoot ethanolic extract was able to inhibit the viability of MCF-7 cell line with the IC50 value of 52.49 microg/ml. S.androgynus shoots and D.esculentum shoots ethanolic extracts did not give an IC50 value against the MCF-7 cell line. S.androgynus, tapioca and D.esculentum shoots ethanolic extracts did not show cytotoxic effect against the Caco-2 and HepG2. There was no IC50-value from any sample against Chang Liver cell line. In conclusion, the antioxidant activity of both fresh and boiled samples were higher than alpha-tocopherol, although fresh vegetable shoots were found to be higher in antioxidant activity compared to boiled shoots. This study also suggested that S.androgynus shoots and tapioca shoots have potential as an anticancer agent against certain breast tumours.
抗氧化剂在抑制和清除自由基方面发挥着重要作用，从而为人类抵御感染和退行性疾病提供保护。文献表明，草药和蔬菜植物的抗氧化活性较高。基于这一事实，本研究旨在测定三种选定的当地蔬菜嫩梢，即双盖蕨（蕨菜嫩梢）、木薯（木薯嫩梢）和白饭树（白饭树嫩梢）的总抗氧化活性和潜在抗癌特性。本研究还旨在确定煮沸对总抗氧化活性的影响，将新鲜嫩梢样品与煮沸嫩梢样品进行比较。在每种情况下，将抗氧化活性与α-生育酚进行比较，使用的两种提取方法是有机法和水提法。此外，使用的两种研究方法是硫氰酸铁（FTC）法和硫代巴比妥酸（TBA）法，吸光度分别为500nm和532nm。P<0.05的单因素方差分析用于确定不同样品之间的显著差异。在细胞毒性研究中，使用了乙醇提取物和几种细胞系，即乳腺癌细胞系（MDA-MB-231和MCF-7）、结肠癌细胞系（Caco-2）、肝癌细胞系（HepG2）和正常肝细胞系（Chang肝细胞系）。通过MTT（3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐）法测定IC50值。抗氧化研究发现，水提物和有机提取物中的所有样品均存在显著差异。水提物的总抗氧化活性值由高到低依次为：木薯（新鲜）>双盖蕨（新鲜）>白饭树（新鲜）>木薯（煮沸）>双盖蕨（煮沸）>白饭树（煮沸）。还发现白饭树嫩梢乙醇提取物能够抑制乳腺癌细胞系MDA-MB-231的活力，IC50值为53.33μg/ml。然而，白饭树嫩梢和双盖蕨嫩梢乙醇提取物并未抑制MDA-MB-231细胞系的活力。同时，木薯嫩梢乙醇提取物能够抑制MCF-7细胞系的活力，IC50值为52.49μg/ml。白饭树嫩梢和双盖蕨嫩梢乙醇提取物对MCF-7细胞系未给出IC50值。白饭树、木薯和双盖蕨嫩梢乙醇提取物对Caco-2和HepG2细胞系未显示出细胞毒性作用。任何样品对Chang肝细胞系均未给出IC50值。总之，新鲜和煮沸样品的抗氧化活性均高于α-生育酚，尽管发现新鲜蔬菜嫩梢的抗氧化活性高于煮沸嫩梢。本研究还表明，白饭树嫩梢和木薯嫩梢具有作为某些乳腺肿瘤抗癌剂的潜力。
