Modulation of erectile dysfunction-associated enzymes and oxidative stress markers by <i>Albizia zygia</i> and <i>Pentaclethra macrophylla</i> leaf extracts: an <i>In vitro</i> evaluation

Pentaclethra macrophylla (PM) and Albizia zygia (AZ) are medicinal plants with known ethnopharmacological use. This study evaluated the in vitro antioxidant potential and enzyme modulatory activities of aqueous extracts of their leaves, focusing on erectile dysfunction (ED)-related targets. PM leaf extract exhibited higher total phenolic content (43.9 mg GAE/g) than AZ (29.4 mg GAE/g), while AZ had higher flavonoid content (0.92 mg QE/g vs 0.70 mg QE/g in PM). Both extracts showed strong antioxidant activity, including DPPH radical scavenging (IC50: PM = 2.34 mg/mL; AZ = 2.32 mg/mL), hydroxyl radical scavenging (IC50: PM = 0.60 mg/mL; AZ = 1.11 mg/mL), and Fe2+ chelating capacity (IC50: PM = 0.63 mg/mL; AZ = 0.30 mg/mL). They also significantly inhibited lipid peroxidation in FeSO4-induced systems (IC50: PM = 4.69 mg/mL; AZ = 4.56 mg/mL). In enzyme assays, PM exhibited stronger acetylcholinesterase (AChE) inhibition (IC50 = 0.45 mg/mL) than AZ (IC50 = 0.52 mg/mL), while AZ showed stronger inhibition of arginase (IC50 = 0.22 mg/mL vs PM = 0.47 mg/mL), ATPdase (IC50 = 0.36 mg/mL), and ADPdase (IC50 = 0.19 mg/mL). These activities suggest that the erectogenic potential of these extracts may stem from their combined antioxidant and enzyme-modulatory mechanisms. These findings justify further investigation into their potential development as plant-based therapeutic agents for ED.