Abstract
Introduction: Both watermelon and Persian melon extracts have various pharmacological properties like anti-diabetic, anti-viral, anti-cancer, and anti-urolithiasis effects.
Objectives: The present study was conducted to investigate the effects of hydroalcoholic extracts of watermelon and Persian melon rind on kidney stone prevention in male Wistar rats.
Materials and Methods: Fifty-six Wister rats were randomly divided into seven groups and treated for 28 days. The first group (healthy control) and the second group (negative control) received drinking water and water containing 1% ethylene glycol, respectively. The third and fourth groups, received 100 mg/kg/d hydroalcoholic extract of watermelon rind and Persian melon rind, respectively in addition to 1% ethylene glycol. The fifth and sixth groups, received 400 mg/kg/d hydroalcoholic extract of watermelon rind and Persian melon rind, respectively in addition to 1% ethylene glycol. The seventh group received 0.5 mEq/kg/d potassium citrate in addition to 1% ethylene glycol for prevention and treatment of kidney stone. A 24-hour urine collection was conducted to determine the levels of sodium, calcium, uric acid, oxalate and citrate concentration. Histological study of calcium oxalate crystals was also performed. The serum levels of urea, creatinine, uric acid, calcium, phosphorus, magnesium, SGPT (serum glutamic-pyruvic transaminase), SGOT (serum glutamic-oxaloacetic transaminase), total antioxidant capacity, and malondialdehyde (MDA) of blood were determined accordingly.
Results: In the present study, administration of high-dose extract of watermelon and Persian melon rind (400 mg/kg/d) and potassium citrate showed significant changes in variables of sodium, calcium, uric acid, citrate, urine volume (P<0.01), blood creatinine, blood uric acid, blood calcium, and serum SGPT (P<0.05). The histological study of calcium oxalate crystals showed a significant reduction in oxalate levels in all prevention groups.
Conclusion: The extracts of watermelon and Persian melon rind are effective in preventing calcium oxalate stones by decreasing the levels of oxalate, sodium, and calcium and increasing citrate levels and urine volume and affecting the total antioxidant capacity. Persian melon rind extract was more effective than potassium citrate and watermelon rind extract in reducing urine sodium. High-dose watermelon rind extract showed similar effects as potassium citrate.