Evaluating the efficacy of Tribulus terrestris on pH dependent uric acid crystallization under experimental condition

Abstract

The increasing incidence of kidney stone disease, particularly due to dietary and metabolic risk factors, highlights the urgent need for effective and natural therapeutic strategies. While most studies focus on calcium oxalate stones, uric acid stones have received comparatively less attention. Tribulus terrestris has been extensively documented in Ayurvedic literature for its effectiveness in preventing kidney stones, especially those formed from calcium oxalate. This study investigates the activity of Tribulus terrestris as a potential inhibitor of uric acid crystallization. The inhibition was evaluated by measuring the delay in induction time and reduction in mean crystal size. Crystallization of uric acid in the presence of aqueous Tribulus terrestris extract showed a notable delay in induction time and reduction in crystal size. At pH 4.5, increasing the extract concentration from 37.3 μg/mL to 149.2 μg/mL led to a 38-fold increase in induction time. A ~3-fold decrease in mean crystal size was observed when extract concentration increased from 0 to 37.3 μg/mL. Phytochemical analysis revealed the presence of phenols, flavonoids, saponins, and sterols. SEM and PXRD confirmed reduced crystallinity, while EDS analysis showed altered C, N, and O composition, suggesting phytochemical incorporation into the uric acid lattice, resulting in inhibition of crystallization.