Phytochemical Analysis and Antioxidant Activity of Cucurbita pepo L Leaves

Abstract

Cucurbita pepo L. leaves used as vegetables were randomly collected from the annual plant
cultivated for its pumpkin in Harare, Zimbabwe to assess the presence of bioactive compounds
in the leaves. Due to the presence of bioactive compounds, there will be a rise in the
consumption of the leaves, which will help to bridge the nutritional gap and provide longterm
food security. The leaves were shade dried in open air and ground into powder using
mortar and pestle. The samples were separately soaked in distilled water and methanol,
filtered and rotary evaporated to obtain the respective aqueous and methanolic concentrates.
The concentrates were subjected to standard preliminary phytochemicals screening, assessment of free radical scavenging activity using α,α-diphenyl-β-picrylhydrazyl (DPPH) and GC-MS analysis. Preliminary phytochemical screening revealed the presence of flavonoids, steroids, saponins, tannins and alkaloids with the methanol extract being more efficient in the extraction of steroids. The extracts were nearly as effective as ascorbic acid in lowering DPPH free radical concentration. The GC-MS results revealed the presence of 7 phytoconstituents in methanol extract. Among these α-amyrin was detected and is considered to be medicinally important for new drug discovery.