Dose-Dependent Dual Effect of Morus nigra L. Extract on Urinary Parameters of Hypertensive Rats

This study investigated the diuretic and antiurolithic effects of the hydroalcoholic extract obtained from Morus nigra L. leaves (HEMN) in female hypertensive rats. The rats were treated orally with vehicle (VEH), hydrochlorothiazide (HCTZ), or HEMN. After 8 h, the urine was analyzed. Besides, the precipitation of calcium oxalate (CaOx) was induced in the urine. The HEMN, at a dose of 0.03 mg/g, increased the volume of urine compared to the VEH-treated group and increased the urinary content of Cl^- , without altering the excretion of Na⁺ and K⁺ . Besides, HENM reduced the elimination of Ca²⁺ in the urine. On the other hand, at a dose of 0.1 mg/g, it significantly reduced the volume of urine excreted, thus suggesting an antidiuretic effect dependent on the dose used. Similarly, HEMN at concentrations of 1 and 3 mg/mL reduced CaOx crystals' formation in monohydrate and dihydrate forms. However, with the increase in the concentration of HEMN to 10 mg/mL, a significant increase in the formation of CaOx crystals was found. In conclusion, M. nigra extract has a dose-dependent dual effect on urinary parameters, which may have a diuretic and antiurolithic effect at lower doses or the opposite effect at higher doses.