Cyclooxygenase Inhibitory Compounds with Antioxidant Activities from Sophora subprostrata

Abstract

As a traditional Chinese medicine, Sophora subprostrata has been used as an antipyretic, antidote and analgesic. For the purpose of searching for bioactive compounds exerting antiinflammatory activity, two-quinolizidine alkaloids were isolated by cyclooxygenase (COX) inhibitory activity-directed chromatographic fractionation from the aerial portion of S. subprostrata. These alkaloids were identified as matrine and oxymatrine, respectively. Matrine showed significant COX-1 inhibitory activity (IC₅₀: 31.3 μM) and moderate COX-2 inhibitory activity (IC₅₀: 188.5 μM), whereas oxymatrine showed less COX-1 (IC₅₀: 197.8 μM) and COX-2 (IC₅₀: 385.1 μM) inhibitory activity. Both matrine and oxymatrine exhibited antioxidant activity in a dose-dependent manner by PMSNADH system test (EC₅₀ 192.5 and 275.8 μM, respectively). This is the first report on cyclooxygenase inhibitory and antioxidant activities from matrine and oxymatrine in vitro and provides certain scientific supports for the medicinal use of these two compounds from S. subprostrata for inflammatory disorders.