Phytochemical screening, antioxidant activity and thin-layer chromatography test of ethanolic extract of whole Praecitrullus fistulosus plant

Background: Natural-antioxidant plants are promising sources of bioactive compounds that support the body’s defence mechanisms against diseases caused by free-radical damage. The aim of this study was to evaluate the antioxidant activity and perform qualitative phytochemical screening of the whole-plant extract of Praecitrullus fistulosus.Materials and Methods: The dried whole plant material was extracted sequentially using ethanol in a Soxhlet apparatus. Antioxidant activity was evaluated via the 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical-scavenging assay. Each test was repeated ten times and averaged.Results: Phytochemical screening of the ethanolic extract revealed the presence of several bioactive classes, including alkaloids, flavonoids, glycosides, steroids, terpenoids, and phenols. Thin-layer chromatography (TLC) of various solvent systems yielded Rf values of ethanolic extract with a variation in solvent (70:20:10, 2:8, 10: 81: 13.5, 9:1, 9:1 and 60: 60: 10) is 0.91, 0.75, 0.91, 0.50, 0.75 and 0.80. The ethanolic whole-plant extract demonstrated the strongest antioxidant activity: its IC₅₀ value was 12.09 µg/mL, considerably lower (i.e. stronger activity) than that of ascorbic acid (31.06 µg/mL). The high phenolic content likely underlies this potent free-radical scavenging ability.Conclusion: The whole plant of Praecitrullus fistulosus exhibits significant antioxidant and free-radical scavenging activity, supporting its traditional use and suggesting potential for development as a natural medicinal resource.