Medicinal plants of Cree communities (Quebec, Canada): antioxidant activity of plants used to treat type 2 diabetes symptoms

Traditional medicines (TM) used to treat symptoms of diabetes by two Cree communities were assessed for their free radical scavenging activity using the stable 1,1-diphenyl-2-picrylhydrazyl radical, and their ability to protect human low-density lipoprotein from Cu2+-mediated oxidation by measuring lag time before the appearance of conjugated dienes and formation of thiobarbituric acid-reactive substances. Water-soluble phenolic content was also measured. A total of 20 medicinal plants from Whapmagoostui and 16 from Mistissini were compared with 16 extracts of plants that were not used medicinally. Medicinal plant extracts, particularly those from Larix laricina, displayed high antioxidant activity, comparable with ascorbic acid, Trolox, and the known antioxidant flavonoids quercetin, epicatechin, catechin. Extracts of Pinaceae and Ericaceae contained the highest levels of phenolics. Factors such as season and area of plant collection, as well as the plant part from which the extract was derived, affected antioxidant activity. Positive correlations were found between the established traditional knowledge of Cree Elders and Healers and the antioxidant activity for medicinal plants used in Mistissini (r = 0.3134; p = 0.058) and in Whapmagoostui (r = 0.5165; p = 0.001). Significant correlations between phenolic content were also seen with the existing ethnobotanical data (r = 0.5015; p = 0.003) and bioassays (r = 0.4178; p = 0.003). These results indicate that a clear majority of plants used by the Cree are excellent sources of antioxidants.

对两个克里族社区用于治疗糖尿病症状的传统药物（TM），采用稳定的1,1 - 二苯基 - 2 - 苦基肼基自由基评估其自由基清除活性，并通过测量共轭二烯出现和硫代巴比妥酸反应物质形成之前的滞后时间，评估其保护人类低密度脂蛋白免受铜离子介导氧化的能力。还测量了水溶性酚类含量。将来自瓦普马古斯图伊的20种药用植物和来自米斯蒂西尼的16种药用植物与16种非药用植物提取物进行了比较。药用植物提取物，特别是来自落叶松的提取物，显示出高抗氧化活性，与抗坏血酸、特洛克斯以及已知的抗氧化类黄酮槲皮素、表儿茶素、儿茶素相当。松科和杜鹃花科植物的提取物含有最高水平的酚类物质。植物采集的季节和地区以及提取所使用的植物部位等因素影响抗氧化活性。在克里族长老和治疗师的既有传统知识与米斯蒂西尼（r = 0.3134；p = 0.058）和瓦普马古斯图伊（r = 0.5165；p = 0.001）所用药用植物的抗氧化活性之间发现正相关。酚类含量与现有的民族植物学数据（r = 0.5015；p = 0.003）和生物测定（r = 0.4178；p = 0.003）之间也存在显著相关性。这些结果表明，克里族使用的绝大多数植物是抗氧化剂的优质来源。