Phytochemical composition and urease inhibitory potential of crude extracts and subsequent fractions of Bauhinia alba

Abstract

The nickel-dependent metalloenzyme, urease, is involved in the hydrolysis of urea to carbon dioxide and ammonia and is an important virulence factor in a variety of pathogenic microorganisms such as Helicobacter pylori, Proteus mirabilis and Klebsiella pneumoniae. Overactivity of urease also plays a role in the emergence of gastric ulcers, hepatic encephalopathy, and urolithiasis, and therefore, urease inhibition is an important therapeutic goal. To find safe and natural alternatives to the artificial inhibitors, the given study examined phytochemical composition and urease inhibitory activity of crude extract and solvent-partitioned fractions of Bauhinia alba roots. The shade-dried roots were impregnated with ethanol and fractionated with the succession of n-hexane, chloroform, ethyl acetate, methanol and butanol. Phytochemical screening showed that the methanol and butanol fractions were strong in flavonoid, tannin, steroid, and reducing sugars, and nonpolar fractions had low amounts of secondary metabolites. The jack bean urease assay was used to determine the urease inhibitory activity, with thiourea being one of the standard inhibitors. The butanol fraction was the most active (93.76% inhibition; IC₅₀ = 29.44 ± 1.09 µg/mL), then the methanol fraction (80.66% inhibition; IC₅₀ = 34.77 ± 2.10 µg/mL). There was a direct association between the richness of polar phytoconstituents and urease inhibition, indicating that flavonoids, tannins and steroids are the main contributors to the enzyme inhibition witnessed. The results confirm the application of Bauhinia alba as a medicine in ethnomedicine and as a prospective source of natural urease inhibitors against the urease-mediated diseases, including gastritis, peptic ulcers, and urinary infections. The research on the isolation, the description, and the mechanistic analysis of active compounds should be continued to create new therapeutic agents of plant-based origins.