Laboratory of Post-harvest of Plant Genetic Resources and Natural Products, Department of Health Sciences, UAM-I, Ciudad de Mexico, Mexico.
Department of Human Biology, College of Sciences and Humanities, Universidad Autónoma de la Ciudad de México (UACM), Ciudad de Mexico, Mexico.
J Med Food. 2022 Jan;25(1):61-69. doi: 10.1089/jmf.2021.0098. Epub 2021 Dec 7.
Lychee is a fruit of Asian origin with an exquisite flavor and an attractive reddish color. However, according to recent reports, the consumption of this fruit reduces the levels of blood glucose with adverse effects on human health such as encephalopathy and hypoglycemic. The objective of this work was to determine if the peel, pulp, and seed of "Brewster" lychee fruits harvested at two stages of maturity had antihyperglycemic effect. This effect was determined by an oral glucose tolerance test using Wistar rats. In addition, ultraviolet-visible spectrophotometry and high-resolution liquid chromatography were used to quantify phenolic compounds, flavonoids, organic acids (OAs), sugars, and antioxidant activity. Results indicated that stage I pulp (immature fruits) and stage II peel and seed (export mature fruits) reduced blood glucose levels, and the effects of the former two were synergistic with metformin. The pulp of mature fruits (stage II), however, lacked a hypoglycemic effect. Additionally, the peel and the seeds of these fruits presented a high antioxidant activity (as determined by DPPH [2,2-diphenyl-2-picryl-hydracyl] and ABTS [2,2-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid] methods), which correlated well with the total content of phenolic compounds. The highest content of polyphenolics, flavonoids, and OAs was found in the extracts of the peel and seeds of both stages of maturity. It was therefore concluded that "Brewster" mature lychees are safe for human consumption, and both the seed and the peel can be useful sources for obtaining new compounds with antihyperglycemic activity.
荔枝是一种亚洲起源的水果，具有精致的风味和诱人的红色。然而，根据最近的报告，食用这种水果会降低血糖水平，对人类健康产生不良影响，如脑病和低血糖。本工作的目的是确定“布鲁斯特”荔枝在两个成熟阶段收获的果皮、果肉和种子是否具有降血糖作用。通过使用 Wistar 大鼠进行口服葡萄糖耐量试验来确定这种作用。此外，使用紫外可见分光光度法和高分辨率液相色谱法来定量酚类化合物、类黄酮、有机酸 (OAs)、糖和抗氧化活性。结果表明，第一阶段的果肉（未成熟的果实）和第二阶段的果皮和种子（出口成熟的果实）降低了血糖水平，前两者的作用与二甲双胍协同。然而，成熟果实（第二阶段）的果肉缺乏降血糖作用。此外，这些水果的果皮和种子具有很高的抗氧化活性（通过 DPPH [2,2-二苯基-2-苦基肼]和 ABTS [2,2-偶氮-双-（3-乙基苯并噻唑啉-6-磺酸）]方法测定），与总酚含量呈良好相关性。在两个成熟阶段的果皮和种子提取物中发现了最高含量的多酚、类黄酮和 OAs。因此，结论是“布鲁斯特”成熟荔枝可安全食用，种子和果皮均可作为获得具有降血糖活性的新化合物的有用来源。
