The role of herbal medicines in treatment of urinary tract diseases

Urinary diseases have affected humankind since ancient time and can persist, with serious medical consequences, throughout the world. Additionally, the incidence of renal disorders especially kidney stones have been enhanced in western countries in the last decades, in relation with economic development. It seems that acute and chronic renal failure and lithiasis (stone formation) occurred due to both nephrolithiasis (stone formation in kidney) and urolithiasis (stone formation in ureter or bladder even both places). Nowadays, alongside synthetic drugs, herbal medicines play a prominent role in treatment and prevention of various diseases. A number of herbal medicines and remedies have been reported for its significant nephroprotective activity, which is probably due to the presence of flavonoids and other effective secondary metabolites in those medicinal plants. Furthermore, literature reveals that the extracts from the leaves and aerial parts of some plants exhibit good potentials to improve kidney damages. Actually among different kidney disorders, there are two main urologic indications for application of herbal drugs as follows (1-3): 1. Inflammatory urinary tract diseases including renal gravel and more severe types of lithiasis, in which herbal remedies mainly of kidney & bladder teas have been used. As a matter of fact, urinary tract inflammation can be treated mainly by medicinal teas that possess a diuretic activity because of the consumption of the water that is ingested by drinking the teas. Actually, in patients with urinary tract infections or stone-related (and other) inflammatory irritations of the urinary tract, increasing the output of a hypo-osmolar urine is observed to be an effective way to clear ascending bacteria, crystallization nuclei, and other inflammatory agents (2). 2. Benign Prostatic Hyperplasia (BPH), for which there are three pathogenic hypothesis as below: A. Increase in the prostatic synthesis of dihydrotestosterone (DHT) & estrogen:androgen rat io B. Elevation in the binding capacity of sex hormonebinding globulin (SHBG) C. Elevation in the levels of inflammatory mediators (prostaglandins & leukotrienes). However, in BPH, saw palmetto berries, nettle root and pumpkin seeds are widely employed (2). Among the various medicinal plants, Arctostaphylos uvaursi (Ericaceae) with chemical composition of arbutin (512%), hydroquinone and tannins (10-20%) is well known for treatment of bacterial inflammatory diseases with three gram of the dried herb, or 400-800 mg of hydroquinone 1Medicinal Plants Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran 2Division of Pharmacy, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada