Phytochemical Profiling and Nutritional Value of Cucumis melo var. aegyptiacus cv. Ismailawi with Antidiabetic Evaluation

Objectives: This study aimed to evaluate the nutritional composition, phytochemical profile, and antidiabetic activity of the Egyptian melon cultivar Cucumis melo L. var. aegyptiacus cv. Ismailawi, focusing on both pulp and seed extracts. Methods: Diabetes was induced in adult male Sprague Dawley rats using a single intraperitoneal dose of streptozotocin (STZ). The animals were orally pretreated with the defatted aqueous ethanol extract of the pulp and the defatted aqueous ethanol and petroleum ether extracts of the seeds (100 mg/kg each). Blood glucose levels were monitored over four weeks and compared with metformin-treated diabetic controls. Nutritional profiling of the pulp was conducted through standard biochemical assays, while phytochemical characterisation of the seed extracts was performed using HPLC and GC/MS. Results: Nutritional profiling of the pulp confirmed its richness in carbohydrates, primarily fructose, along with substantial amounts of vitamins (C and A) and minerals, particularly potassium and calcium, as well as high pectin and notable glutaric acid content. In contrast, the seeds were characterized by phenolic and fatty acid constituents, dominated by benzoic acid, naringenin, ergosta-5,7-dien-3-ol, and linoleic acid methyl ester. Functionally, both pulp and seed extracts demonstrated antidiabetic activity; however, the seed extracts showed superior efficacy. While the defatted aqueous-ethanol pulp extracts reduced glucose levels by 45%, the petroleum ether and defatted aqueous-ethanol seed extracts achieved markedly higher reductions of 65% and 62%, respectively, approaching the glucose-lowering effect of metformin (70%) after four weeks. Conclusions: These findings highlight the nutritional richness of the pulp and the bioactive metabolites in the seeds of Cucumis melo L. var. aegyptiacus cv. Ismailawi, supporting its potential as a functional food and natural antidiabetic agent.