Antihyperuricemic lignans from the leaves of Phyllanthus niruri

The methanol extract from the leaves of Phyllarithus niruri L. showed oral antihyperuricemic activity in potassium oxonate-and uric acid-induced hyperuricemic rats. Fractionation of the extract by resin chromatography led to the isolation of a less polar fraction which exhibited the highest reduction of plasma uric acid. Further antihyperuricemic-guided purification of the fraction afforded three lignans, phyllanthin (1), hypophyllanthin (2) and phyltetralin (3), of which 1 significantly reversed the plasma uric acid level of hyperuricemic animals to its normal level in a dose-dependent manner, comparable to that of allopurinol, benzbromarone and probenecid which are used clinically for the treatment of hyperuricemia and gout. Thus, the lignans of A niruri are potential antihyperuricemic agents worthy of further investigation.