Polyphenol Profile, Antioxidant Potential, Vitamin C and Mineral Contents of Crude Parsley Leaves Extract (Petroselinum crispum) and Its Isolated Apigenin: A Comparative Study

Petroselium crispum or parsley is a typical culinary vegetable that is used as a flavouring and aromatic food additive. The aim of this research was to purify a major flavonoid present in parsley leaves, apigenin and evaluate the polyphenol, mineral and vitamin C contents in parsley leaves extract (PLE); in addition, the study compared antioxidant activities of ethanolic PLE with purified apigenin (AP), applying different non-enzymatic strategies using ascorbic acid (AA) as a reference. A complete screening for bioactive compounds in the ethanolic PLE was performed by HPLC analysis. The research outcomes indicated that purification of apigenin was successfully achieved by column chromatography with a high yield and purity; a single peak in the HPLC chromatogram confirmed this. The analysis revealed that contents of total phenolic and flavonoid in the ethanolic PLE were 75.91 ± 3.33 mg. g–1 TA Eq and 15.61 ± 0.18 mg. g–1 respectively; vitamin C is found to be 4.01 mg. g–1. Our results indicated that among the trace minerals in parsley leaves, calcium and sodium documented the highest values; 14.13 mg. g–1 and 8.51 mg. g–1, while copper and manganese had the lowest values; 0.02 mg. g–1 and 0.012 mg. g–1 respectively. Finally, our findings demonstrated that purified AP had superior potential than ethanolic PLE for reducing power, total antioxidant, nitric oxide and superoxide scavenging activities. In contrast, the ethanolic PLE exhibited greater antioxidant activity than AP towards suppressing the DPPH and hydroxyl radicals.