Phenolics extract of Tetrapleura tetraptera fruit inhibits xanthine oxidase and Fe2+-induced lipid peroxidation in the kidney, liver, and lungs tissues of rats in vitro

The phenolics composition and inhibitory activity of Tetrapleura tetraptera fruit extract on xanthine oxidase (XO) and Fe2+-induced lipid peroxidation in the kidney, liver and lungs tissues of rats were evaluated in vitro. Phenolics (flavonoids and phenolic acids) were quantified using reverse-phase high performance liquid chromatrography coupled with diode array detection (HPLC-DAD). The XO and Fe2+-induced lipid peroxidation inhibitory abilities of the extract were evaluated using spectrophotometric methods. The extract contained some flavonoids and phenolic acids, including catechin, epicatechin, rutin, quercetin, luteolin, apigenin; gallic, chlorogenic, caffeic and ellagic acids that are beneficial to health. The extract inhibited XO in the kidney, liver and lungs tissues in a dose-dependent manner. The half-maximal inhibitory concentrations (IC50) of the extract on XO from the tissues varied significantly (P < 0.05), and were in the order of liver > kidney > lungs. The extract also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern, having IC50 in the order of liver > lungs > kidney. T. tetraptera fruit extract could be a promising nutraceutical for preventing and managing hyperuricaemia and the associated disease conditions, due to its ability to inhibit XO; this bioactivity is attributable to combined effect of its flavonoids and phenolic acids.