Pesticidal and antioxidant activity of solvent extracts of pods and leaves of Psophocarpus tetragonolobus (Winged Bean)

The demand for natural pesticides and antioxidants is rising due to the adverse effects of synthetic chemicals on human health and the environment. Psophocarpus tetragonolobus (winged bean), a tropical legume, is recognized as a rich source of nutrients and bioactive compounds. This study evaluated the pesticidal and antioxidant potential of hot water, cold water, and water: acetone (1:1) crude extracts of pods and leaves of P. tetragonolobus. The pesticidal activity was tested against Aphis fabae (black aphids), while antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, total polyphenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC). Phytochemical screening was also conducted to identify the compounds present. Among the extracts, water: acetone extracts exhibited the highest pesticidal activity, causing 100% mortality of A. fabae at 10,000 mg L⁻¹ for both pods and leaves. Toxicity was concentration- and time-dependent, with LD₅₀ values of 202.50 mg L⁻¹ at 12 hours and 162.26 mg L⁻¹ at 24 hours for leaves. Water: acetone extracts also showed the strongest antioxidant activity, with IC₅₀ values of 356.76 mg L⁻¹ and 395.90 mg L⁻¹, TPC of 241.50 mg(GAE)/g and 159.83 mg(GAE)/g, TFC of 125.60 mg(QUE)/g and 100.60 mg(QUE)/g, and TAC of 245.63 mg(AAE)/g and 212.74 mg(AAE)/g for leaves and pods, respectively. These findings highlight the potent pesticidal and antioxidant properties of water: acetone extracts of P. tetragonolobus, suggesting their potential as eco-friendly alternatives for pest management and natural antioxidant sources.