Investigation of In Vitro Antiurolithic Property of Purified Polyphenols from Selected Medicinal Plants to Inhibit Renal Calculi

Background: Urolithiasis (UL) is the process of formation of calculi in the urinary system that includes, ureterolithiasis, urethrolithiasis and cystolithiasis, and is prevalent in the developing and underdeveloped countries. Nevertheless, exact natural drugs are not available to control the nucleation and aggregation of various renal calculi. Objective: To screen the plant species (Holarrhena antidysenterica, Alternanthera sessilis, Solanum nigrum and Centella asiatica) and identify the polyphenolic fraction that controls the formation of renal calculi. Methods: Different extraction methodologies were attempted to prepare the crude extracts. Spectroscopic analysis was performed to determine the nucleation and aggregation of renal calculus. TLC, PTLC and LC-MS-PDA analyses were executed to identify the polyphenols in the eluates. Results: An appreciable inhibition of nucleation (Nu) and aggregation (Agg) of calcium oxalate (CaOx) (Nu- 96.9±1.3%; Agg- 98.7±2.8%), struvite (Nu- 96.3±2.1%; Agg- 97.8±1.1%) and calcium phosphate (CaP) (Nu- 97.6±3.0%; Agg- 97.4±1.6%) crystals were recorded by the pressurized hot water bark extract of Holarrhena antidysenterica more than the other extracts. The studies proved significant nucleation inhibition of all types of crystals by the chromatography (planar and column) eluates of the plant species. A substantial dissolution of CaOx and CaP kidney stones was observed in the PAEs, and the chromatography eluates of Holarrhena antidysenterica and Solanum nigrum. The LC-MS-PDA analysis of Solanum nigrum revealed the presence of few novel polyphenols such as carboxylated caffeic acid phenethylester and flavonoid pentoside. Conclusion: The present investigation concludes the significant antiurolithic activity of purified polyphenols present in the Holarrhena antidysenterica and Solanum nigrum.