Phytochemical analysis of medicinal plants with kidney protective activities.

In view of the increasing number of patients undergoing kidney dialysis or transplant every year, a survey of the literature on renal protective medicinal plants was undertaken. Most of them are from traditional Chinese medicine (TCM). Although many of the medicinal herbs reported have not been investigated in terms of active chemical ingredients, some do have compounds well characterized. They fall into a wide range of structures. Several groups of compounds with well established activities are discussed. These include: antioxidant phenolic compounds like tannins, flavonoids, isoflavonoids, unsaturated organic acids and lignans; circulation enhancing compounds like saponins, and basic alkaloids with multiple targets (G-protein coupled receptors). Also presented are proinflammatory and antiinflammatory fatty acids like linoleic (n-6) and α-linolenic (n-3) acids, respectively. Attention is also drawn to the plants containing nephrotoxic aristolochic acid. Different directions of future research are also presented. We hope that this review may provide some leads for new drug discovery and development, and more rational application of TCM.