Anti-inflammatory and Xanthine Oxidase Inhibitor of <i>Melicope Ptelefolia</i> Leaves - A Promising Source of Gout Treatment

Background The leaves and rhizomes of Melicope pteleifolia are utilized for their therapeutic properties, being applied to treat various ailments such as scabies, wounds, ulcers, sore throats, rheumatism, eczema, dermatitis, bruises, and snake bites. The goal of this work is to investigate the anti-inflammatory and xanthine oxidase inhibitory activities as well as the isolation of bioactive compounds of extracts and fractions from Melicope ptelefolia . Methods The dried plants were extracted exhaustedly with 96% ethanol, the solvent was evaporated, and the resulting extracts (MPE) were partitioned successively with hexane, ethyl acetate, and methanol through flash chromatography to obtain three sub-fractions (MPH, MPEA, and MPM). The macrophage cell line RAW264.7 was used to assess the anti-inflammatory activity via inhibition of secretion of mediator (NO and TNF-α). The DPPH, ABTS, RP assay, and xanthine oxidase inhibition were applied to investigate the antioxidant and reducing uric acid in vitro, respectively. Structural chemicals were identified by NMR methods. Results All the extracts manifested anti-inflammatory and antioxidant activities. MPEA fraction showed a better antioxidant and NO inhibitory effects than that of MPE and MPH, while MPH fraction was stronger than those of MPE, MPEA, and MPM in the TNF-α inhibition experiment. From the most active fraction (MPEA), eight compounds (1-8) were isolated and identified by column chromatography. Of which, quercetin (3), quercitrin (7), kaempferol (2), and Luteolin 7 glucoside (8) were the potential compounds for anti-inflammation and suppressing activity of xanthine oxidase. Conclusions Melicope ptelefolia exhibited significant anti-inflammatory, antioxidant, and xanthine oxidase inhibitory properties, showing that it was a promising source for developing medications targeting inflammation and elevated uric acid levels. Its bioactive compounds are potentially used in pharmaceuticals to treat conditions like gout and other inflammatory illnesses.