Antioxidant potential and phenolic acid content of certain cucurbitaceous plants cultivated in Egypt

Many species belonging to Cucurbitaceae family have long been regarded as food, medicinal plants, or both. Preliminary phytochemical screening of Citrullus colocynthis L., Cucumis sativus L. and Momordica charantia L. herbs showed the presence of phenolic compounds. Quantitative analysis of total phenolic compounds using Folin-Ciocalteu reagent revealed the presence of 50.87 mg GAE g-1, 56.58 mg GAE g-1 and 42.36 mg GAE g-1 in C. colocynthis L., C. sativus L. and M. charantia L. herbs, respectively. HPLC analysis of phenolic content showed the presence of chlorogenic acid (16.3 mg per 100g dry sample and 27.7 mg per 100 g-1 dry samples in C. colocynthis L. and C. sativus L., respectively) and gallic acid (26.7 mg per 100 g dry sample) as a major phenolic acids in M. charantia L. herb. The antioxidant activity of the herb of plants under investigation was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and total antioxidant capacity was determined in terms of GAE. This study showed that C. sativus L. is the most active antioxidant, followed by C. colocynthis L., while M. charantia L. has the least antioxidant activity.