Department of Biochemistry, Faculty of Science, Laboratory of Phytobiochemistry and Medicinal Plants Studies, University of Yaoundé I, PO Box 812, Yaoundé, Cameroon.
BMC Complement Altern Med. 2013 Mar 18;13:63. doi: 10.1186/1472-6882-13-63.
The recent epidemic of diabetes mellitus (DM) in Africa, coupled with rampant poverty, is an indication of the urgent need to develop new efficacious, cheaper and more available drugs to face this growing public health challenge. A number of plants products among which the protein-rich Cucurbitaceae seeds are commonly used in traditional medicine with increasing acclaimed efficacy against DM. The aim of this study was to analyse and evaluate the hypoglycaemic activity of storage proteins of five species of Cucurbitaceae, which include Telfairia occidentalis, Citrullus lanatus, Lagenaria siceraria, Cucumeropsis mannii and Cucurbita moschata.
The different families of storage proteins were extracted following differential solubility, and their contents were estimated using the Bradford method. The analysis of these proteins was done by electrophoresis in non-denaturing and denaturing conditions. The evaluation of hypoglycaemic properties of various globulins extracted was performed on male Wistar rats by the oral glucose tolerance test.
The results showed that among the proteins extracted, globulins constitute the most abundant class of storage proteins in all five species selected. Citrullus lanatus and Cucurbita moschata presented the highest levels of globulin (275.34 and 295.11 mg/g dry matter, respectively). The results of electrophoresis showed that all species possess acidic and neutrals albumins and globulins, with molecular weight of protein subunits ranging from 6.36-44.11 kDa for albumins, 6.5-173.86 kDa for globulins and 6.5-49.66 kDa for glutelins. The 6.36 kDa of albumin subunit protein and the 6.5 kDa of globulin subunit protein were present in all the species. The oral glucose tolerance test showed that the globulins of the seeds of all species except Cucumeropsis mannii caused significant drop in blood sugar (88 - 137.80%, compared to the controls, p<0.05).
These findings showed that the selected Cucurbitaceae seeds contained globulins with significant anti-hyperglycaemic activity. It is therefore highly encouraged to pursue investigations towards development of peptide-drugs and/or phytomedicines from these bioactive proteins which could be used as affordable alternative therapy against DM.
近年来，非洲糖尿病（DM）的流行，加上猖獗的贫困，表明迫切需要开发新的有效、更便宜、更易得的药物来应对这一日益严重的公共卫生挑战。许多植物产品，包括富含蛋白质的葫芦科种子，在传统医学中被广泛使用，并对 DM 有着越来越高的疗效。本研究旨在分析和评估 5 种葫芦科植物的储存蛋白的降血糖活性，这 5 种植物包括 Telfairia occidentalis、Citrullus lanatus、Lagenaria siceraria、Cucumeropsis mannii 和 Cucurbita moschata。
采用差异溶解度法提取不同的储存蛋白家族，并采用 Bradford 法估算其含量。通过非变性和变性条件下的电泳对这些蛋白质进行分析。通过口服葡萄糖耐量试验，在雄性 Wistar 大鼠上评价各种球蛋白提取物的降血糖特性。
结果表明，在所选择的 5 种植物中，球蛋白是所有植物中最丰富的储存蛋白。Citrullus lanatus 和 Cucurbita moschata 球蛋白含量最高（分别为 275.34 和 295.11mg/g 干物质）。电泳结果表明，所有物种都含有酸性和中性白蛋白和球蛋白，白蛋白亚基的蛋白质分子量范围为 6.36-44.11kDa，球蛋白为 6.5-173.86kDa，谷蛋白为 6.5-49.66kDa。所有物种都存在 6.36kDa 的白蛋白亚基蛋白和 6.5kDa 的球蛋白亚基蛋白。口服葡萄糖耐量试验表明，除 Cucumeropsis mannii 外，所有物种的种子球蛋白均显著降低血糖（与对照组相比，88-137.80%，p<0.05）。
这些发现表明，所选葫芦科种子含有具有显著降血糖活性的球蛋白。因此，强烈鼓励进一步研究从这些具有生物活性的蛋白质中开发肽类药物和/或植物药，作为治疗糖尿病的负担得起的替代疗法。
