Zonyane Samkele, Fawole Olaniyi A, la Grange Chris, Stander Maria A, Opara Umezuruike L, Makunga Nokwanda P
Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Merriman Avenue, Stellenbosch 7602, South Africa.
South African Research Chair in Postharvest Technology, Department of Horticultural Science, Stellenbosch University, Private Bag X1, Merriman Avenue, Stellenbosch 7602, South Africa.
Antioxidants (Basel). 2020 Feb 13;9(2):152. doi: 10.3390/antiox9020152.
Extracts of (cancer bush) exhibit considerable qualitative and quantitative chemical variability depending on their natural wild origins. The purpose of this study was thus to determine bioactivity of extracts from different regions using in vitro antioxidant and anti-cancer assays. Extracts of the species are complex and are predominantly composed of a species-specific set of triterpene saponins (cycloartanol glycosides), the sutherlandiosides, and flavonoids (quercetin and kaempferol glycosides), the sutherlandins. For the Folin-Ciocalteu phenolics test values of 93.311 to 125.330 mg GAE/g DE were obtained. The flavonoids ranged from 54.831 to 66.073 mg CE/g DE using the aluminum chloride assay. Extracts from different sites were also assayed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and ferric reducing anti-oxidant power (FRAP) methods. This was followed by an in vitro Cell Titer-Glo viability assay of various ecotypes using the DLD-1 colon cancer cell line. All test extracts displayed anti-oxidant activity through the DPPH radical scavenging mechanism, with IC values ranging from 3.171 to 7.707 µg·mL. However, the degree of anti-oxidant effects differed on a chemotypic basis with coastal plants from Gansbaai and Pearly Beach (Western Cape) exhibiting superior activity whereas the Victoria West inland group from the Northern Cape, consistently showed the weakest anti-oxidant activity for both the DPPH and FRAP methods. All extracts showed cytotoxicity on DLD-1 colon cancer cells at the test concentration of 200 µg·mL but plants from Colesburg (Northern Cape) exhibited the highest anti-cancer activity. These findings confirm that specimens display variability in their bioactive capacities based on their natural location, illustrating the importance of choosing relevant ecotypes for medicinal purposes.
（癌草）提取物因其天然野生来源不同，在定性和定量化学性质上表现出显著差异。因此，本研究旨在通过体外抗氧化和抗癌试验来测定不同地区提取物的生物活性。该物种的提取物成分复杂，主要由一组特定的三萜皂苷（环阿尔廷醇糖苷，即sutherlandiosides）和黄酮类化合物（槲皮素和山奈酚糖苷，即sutherlandins）组成。福林 - 西奥尔特酚类物质测试值为93.311至125.330毫克没食子酸当量/克干提取物。采用氯化铝法测定黄酮类化合物含量，范围为54.831至66.073毫克儿茶素当量/克干提取物。还使用2,2 - 二苯基 - 1 - 苦基肼（DPPH）自由基清除法和铁还原抗氧化能力（FRAP）法对不同产地的提取物进行了检测。随后，使用DLD - 1结肠癌细胞系对各种生态型进行了体外Cell Titer - Glo活力测定。所有测试提取物都通过DPPH自由基清除机制表现出抗氧化活性，IC值范围为3.171至7.707微克·毫升。然而，抗氧化效果的程度因化学型而异，来自甘斯拜和珍珠滩（西开普省）的沿海植物表现出更强的活性，而北开普省维多利亚西部内陆组在DPPH和FRAP方法中始终表现出最弱的抗氧化活性。所有提取物在200微克·毫升的测试浓度下对DLD - 1结肠癌细胞均表现出细胞毒性，但来自科尔斯堡（北开普省）的植物表现出最高的抗癌活性。这些发现证实，标本的生物活性能力因其天然产地不同而存在差异，这说明了为药用目的选择相关生态型的重要性。
