Joshi Tripti, Mandal Sumit Kumar, Puri Sonakshi, Asati Vidushi, Deepa P R, Sharma Pankaj Kumar
Department of Biological Sciences, Birla Institute of Technology and Science (BITS), Rajasthan, India.
Front Plant Sci. 2023 Mar 8;14:1131173. doi: 10.3389/fpls.2023.1131173. eCollection 2023.
Phenolic phytochemicals are known for antioxidant-mediated pharmacological effects in various diseases (diabetes, cancer, CVDs, obesity, inflammatory and neurodegenerative disorders). However, individual compounds may not exert the same biological potency as in combination with other phytochemicals. (Guar), an underutilized semi-arid legume which has been used as a traditional food in Rajasthan (India), is also a source of the important industrial product guar gum. However, studies on its biological activity, like antioxidant, are limited.
We tested the effect of seed extract to enhance the antioxidant activity of well-known dietary flavonoids (quercetin, kaempferol, luteolin, myricetin, and catechin) and non-flavonoid phenolics (caffeic acid, ellagic acid, taxifolin, epigallocatechin gallate (EGCG), and chlorogenic acid) using DPPH radical scavenging assay. The most synergistic combination was further validated for its cytoprotective and anti-lipid peroxidative effects in cell culture system, at different concentrations of the extract. LC-MS analysis of purified guar extract was also performed.
In most cases, we observed synergy at lower concentrations of the seed extract (0.5-1 mg/ml). The extract concentration of 0.5 mg/ml enhanced the antioxidant activity of Epigallocatechin gallate (20 µg/ml) by 2.07-folds, implicating its potential to act as an antioxidant activity enhancer. This synergistic seed extract-EGCG combination diminished the oxidative stress nearly by double-fold when compared with individual phytochemical treatments in cell culture. LC-MS analysis of the purified guar extract revealed some previously unreported metabolites, including catechin hydrate, myricetin-3-galactoside, gossypetin-8-glucoside, and puerarin (daidzein-8-C-glucoside) which possibly explains its antioxidant enhancer effect. The outcomes of this study could be used for development of effective nutraceutical/dietary supplements.
酚类植物化学物质因其在抗氧化介导的多种疾病（糖尿病、癌症、心血管疾病、肥胖症、炎症和神经退行性疾病）中的药理作用而闻名。然而，单个化合物可能不会像与其他植物化学物质联合使用时那样发挥相同的生物效力。瓜尔豆是一种未得到充分利用的半干旱豆类，在印度拉贾斯坦邦一直被用作传统食物，它也是重要工业产品瓜尔胶的来源。然而，关于其抗氧化等生物活性的研究有限。
我们使用DPPH自由基清除试验，测试了瓜尔豆种子提取物对知名膳食黄酮类化合物（槲皮素、山奈酚、木犀草素、杨梅素和儿茶素）以及非黄酮类酚类化合物（咖啡酸、鞣花酸、紫杉叶素、表没食子儿茶素没食子酸酯（EGCG）和绿原酸）抗氧化活性的增强作用。在细胞培养系统中，针对不同浓度的提取物，对最具协同作用的组合进行了细胞保护和抗脂质过氧化作用的进一步验证。还对纯化的瓜尔豆提取物进行了液相色谱 - 质谱分析。
在大多数情况下，我们在较低浓度（0.5 - 1毫克/毫升）的种子提取物中观察到协同作用。0.5毫克/毫升的提取物浓度使表没食子儿茶素没食子酸酯（20微克/毫升）的抗氧化活性提高了2.07倍，这表明其有作为抗氧化活性增强剂的潜力。与细胞培养中单独的植物化学物质处理相比，这种种子提取物与EGCG的协同组合使氧化应激降低了近两倍。纯化的瓜尔豆提取物的液相色谱 - 质谱分析揭示了一些先前未报道的代谢物，包括儿茶素水合物、杨梅素 - 3 - 半乳糖苷、棉花皮素 - 8 - 葡萄糖苷和葛根素（大豆苷元 - 8 - C - 葡萄糖苷），这可能解释了其抗氧化增强作用。本研究结果可用于开发有效的营养保健品/膳食补充剂。
