Food Chemistry and Nutrition Science Laboratory, Agricultural Research Station, College of Agriculture, Virginia State University, Petersburg, VA 23806, USA.
Cooperate Extension, College of Agriculture, Virginia State University, Petersburg, VA 23806, USA.
Nutrients. 2023 Apr 17;15(8):1929. doi: 10.3390/nu15081929.
Obesity and diabetes, often characterized as "metabolic syndrome", have been recognized as two of the most important public health issues worldwide. The objective of the present research was to evaluate green and yellow papaya for anti-oxidation and anti-diabetic properties. Leaves, skin, pulp, and seed samples from papayas were freeze-dried and then extracted in water or 80% methanol. The extracts were used to determine total polyphenolic content and anti-oxidation activities, and to determine biological activities, including glucose uptake, Glut-2 expression, triglyceride reduction, and wound-healing activity. Our data demonstrated that methanol and water extracts of green and yellow papaya have similar concentrations of polyphenols in skin (10-20 mg/g dry powder), leaf (25-30 mg/g dry powder), and pulp (1-3 mg/g dry powder) fractions. However, both methanol and water extracts of seeds from yellow papaya have substantially higher concentrations of polyphenols compared to green papaya. Both water and methanol extracts of yellow papaya exhibited higher anti-oxidation activity compared to green papaya in skin (50-60%), pulp (200-300%), and seeds (10-800%). Old leaves also showed greater anti-oxidation activity (30-40%) compared to new leaves. Pulp extracts from both yellow and green papaya stimulated greater glucose uptake, but only pulp from green papaya stimulated glucose uptake in muscle cells. Similarly, pulp extract stimulated glucose transporter Glut-2 expression in liver cells. The skin, pulp, and seeds of green or yellow papaya showed triglyceride-lowering activity in liver cells by 60-80%, but samples taken from yellow papaya had a more potent effect. Seeds from both green and yellow papaya significantly stimulated the migration of fibroblasts in the wounded area by 2-2.5-fold compared to the untreated control. Consistent with these data, seeds from both green and yellow papaya also significantly stimulated collagen synthesis in fibroblast cells by almost 3-fold. In conclusion, our data indicate that different parts of papaya produce stimulatory effects on glucose uptake, Glut-2 expression, TG reduction, and wound-healing activities. This study concludes that different parts of the papaya can be beneficial for preventing diabetes and diabetes-related wound healing.
肥胖和糖尿病通常被认为是“代谢综合征”，已被确认为全球最重要的公共卫生问题之一。本研究的目的是评估青木瓜和黄木瓜的抗氧化和抗糖尿病特性。木瓜的叶、皮、果肉和种子样本经冷冻干燥后，分别用水或 80%甲醇提取。利用提取物测定总多酚含量和抗氧化活性，并测定葡萄糖摄取、Glut-2 表达、甘油三酯降低和伤口愈合活性等生物活性。我们的数据表明，青木瓜和黄木瓜的甲醇和水提取物在果皮（10-20mg/g 干重）、叶片（25-30mg/g 干重）和果肉（1-3mg/g 干重）部分的多酚浓度相似。然而，黄木瓜的甲醇和水种子提取物中的多酚浓度明显高于青木瓜。黄木瓜的水和甲醇提取物在果皮（50-60%）、果肉（200-300%）和种子（10-800%）中均表现出比青木瓜更高的抗氧化活性。老叶的抗氧化活性也高于新叶（30-40%）。黄木瓜和青木瓜的果肉提取物均能刺激葡萄糖摄取，但只有青木瓜的果肉提取物能刺激肌肉细胞摄取葡萄糖。同样，果肉提取物能刺激肝细胞葡萄糖转运蛋白 Glut-2 的表达。青木瓜和黄木瓜的果皮、果肉和种子在肝细胞中均能降低甘油三酯，达 60-80%，但黄木瓜的效果更强。黄木瓜和青木瓜的种子均能使纤维母细胞在伤口部位的迁移增加 2-2.5 倍，与未处理的对照组相比。与这些数据一致的是，青木瓜和黄木瓜的种子均能使纤维母细胞中的胶原蛋白合成增加近 3 倍。综上所述，我们的数据表明，木瓜的不同部位对葡萄糖摄取、Glut-2 表达、TG 降低和伤口愈合活性有刺激作用。本研究表明，木瓜的不同部位可能有益于预防糖尿病和糖尿病相关的伤口愈合。
