In vitro effects of two bioactive compounds, gallic acid and methyl gallate, on urolithiasis.

INTRODUCTION AND OBJECTIVES

This study aimed to evaluate the role of two widely distributed natural phenolic compounds, gallic acid (GA) and methyl gallate (MG), in an in vitro model of urolithiasis, by using the methodology of calcium oxalate (CaOx) crystals formation, which is the most common type of urinary or kidney stones.

MATERIAL AND METHODS

The compounds GA and MG were subjected to anti-crystallization activities in different concentrations (0.003-0.03 mg/mL), and the quantity and morphology of crystals were determined by microscopy after 60 min.

RESULTS

GA inhibited about 44-57% of the total CaOx crystals formation, while MG inhibited about 48.35%, when compared to vehicle-exposed samples (distilled water; negative control group). GA and MG exposure inhibited monohydrate type calculi formation, which is considered the most common and harmful crystal category. The compounds also decreased absorbance, which in turn is related to reduced CaOx aggregation and precipitation.

CONCLUSIONS

Altogether, this study shows, for the first time, that GA and MG are promising compounds with antiurolithiatic properties, opening new perspectives for future in vivo evaluations of the potential of these compounds in the treatment and/or prevention of urinary or kidney stones.