Herbal medicines and chronic kidney disease.

Alternative and indigenous systems of medicine are popular amongst the poorer sections of society in the developing world. Their use in the developed world has also increased in recent times. The source and composition of these medicines vary in different parts of the world, but herbs and other botanicals are central to these systems. Largely outside the ambit of regulatory control, herbal remedies are prepared by quasi-trained herbalists and not tested for safety. Toxicity can occur when a herb with unknown toxicity is consumed, incorrect identification leads to substitution of an innocuous herb with a toxic one, preparations are contaminated with toxic non-herbal compounds or when a herb potentiates the nephrotoxic effect of a conventional therapy. Renal injury has been reported in association with several herbs. The best-known herb-induced chronic kidney disease (CKD) is aristolochic acid nephropathy. The condition is characterized by progressive interstitial nephritis, with a proportion of patients developing urothelial malignancies. The toxic compound is aristolochic acid (AA); AA-DNA adducts have been identified in the renal and urothelial tissues. Recent evidence suggests that AA also contributes to the development of Balkan endemic nephropathy. The role of herbs has been postulated in the development of CKD in other parts of the developing world, especially amongst the rural population. Public awareness and regulation of use of herbal medicines are required to eradicate this entity from the community.