Diabetes mellitus is a metabolic disorder which is associated with debilitating complications including eye disease, kidney disorder, and diabetic foot disease. One of the mechanisms implicated in the pathogenesis of diabetic complications is the polyol pathway. This study evaluated the inhibitory effect of aqueous extract of four tropical fruits, namely apple (Malus domestica Borkh.), banana (Musa paradisiaca Linn.), pawpaw (Carica papaya Linn.), and watermelon (Citrullus lanatus (Thunb.) Matsum & Nakai), on the activities of polyol pathway enzymes (aldose reductase and sorbitol dehydrogenase). All the fruits, with the exception of banana, displayed stronger inhibition of sorbitol dehydrogenase than aldose reductase which culminated in low IC50 for the inhibition of sorbitol dehydrogenase. Of the fruit extracts tested, pawpaw inhibited both aldose reductase and sorbitol dehydrogenase most effectively with IC50 of 150.78 μg/mL and 46.30 μg/mL, respectively. Lineweaver-Burk plot also revealed that the pawpaw extract inhibited aldose reductase competitively while sorbitol dehydrogenase was inhibited in a mixed non-competitive manner. Aqueous extract of pawpaw fruit effectively inhibited polyol pathway enzymes, and this may be attributed to rich nutritional and phytochemical composition of the fruit. Consequently, the consumption of pawpaw fruit may contribute to the amelioration of diabetic complications.

中文翻译：

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Carica木瓜Linn。水果提取物抑制醛糖还原酶和山梨糖醇脱氢酶的活性：改善糖尿病并发症的可能机制

糖尿病是一种代谢紊乱，与包括眼部疾病，肾脏疾病和糖尿病足疾病在内的衰弱性并发症有关。涉及糖尿病并发症的机制之一是多元醇途径。这项研究评估了四种热带水果，苹果（Malus domestica Borkh。），香蕉（Musa paradisiaca Linn。），木瓜（Carica papaya Linn。）和西瓜（Citrullus lanatus（Thunb。））的水提取物的抑制作用。 Nakai），有关多元醇途径酶（醛糖还原酶和山梨糖醇脱氢酶）的活性。除香蕉外，所有水果对山梨糖醇脱氢酶的抑制作用均比醛糖还原酶强，后者对抑制山梨糖醇脱氢酶的IC50较低。在测试的水果提取物中，木瓜最有效地抑制醛糖还原酶和山梨糖醇脱氢酶，IC50分别为150.78μg/ mL和46.30μg/ mL。Lineweaver-Burk图还显示，木瓜提取物竞争性地抑制了醛糖还原酶，而山梨糖醇脱氢酶则以非竞争的方式被抑制。木瓜果实的水提物有效抑制了多元醇途径的酶，这可能归因于该果实丰富的营养和植物化学成分。因此，食用木瓜果实可能有助于改善糖尿病并发症。Lineweaver-Burk图还显示，木瓜提取物竞争性地抑制了醛糖还原酶，而山梨糖醇脱氢酶则以非竞争的方式被抑制。木瓜果实的水提物有效抑制了多元醇途径的酶，这可能归因于该果实丰富的营养和植物化学成分。因此，食用木瓜果实可能有助于改善糖尿病并发症。Lineweaver-Burk图还显示，木瓜提取物竞争性地抑制了醛糖还原酶，而山梨糖醇脱氢酶则以非竞争的方式被抑制。木瓜果实的水提物有效抑制了多元醇途径的酶，这可能归因于该果实丰富的营养和植物化学成分。因此，食用木瓜果实可能有助于改善糖尿病并发症。