PDE5A and erectile dysfunction: Previous studies confirmed that KP phytoconstituents like 5,7-dimethoxyflavone and 5,7,40-trimethoxyflavone were reported to have inhibitory activity against phosphodiesterase 5 (PDE5), suppression of NO production, increasing male libido, and improving erectile dysfunction in treated males [17, 18, 23–25, 90].