Potential of Purified Flavonoid from Citrus limon L. Seeds to Inhibit the Urease Activity and Restrict the Formation of Struvite Stone: In vitro Study

Background: Effective inhibition of pathogenic bacterial urease activity aligned with satisfied dissolution of struvite stone by purified flavonoid moieties can overcome several lifethreatening renal disorders. Objective: The objective of this study was to investigate the in vitro inhibition of urease enzyme and an effective control over the formation of infectious renal stone (Struvite stone) by the extract and purified flavonoid of Citrus limon seeds. Methods: Standard spectrophotometry analysis to determine urease activity, Gel diffusion method for in vitro antibacterial activity, Artificial Neural Network (ANN) to validate the urease inhibitory activity, and LC-MS-PDA analysis to predict the structures of polyphenols were employed. Results: Complete urease inhibition was noticed in hot water extract (HWE) and 50% ethanolic extract, and an appreciable inhibition was recorded by preparative thin layer chromatography (PTLC) purified polyphenols (78.3±2.6%). A satisfactory struvite stone dissolution of about 49.6±3.2% and 40.9±2.1%, was recorded by HWE and PTLC eluate, respectively. ANN-based training model proved a significant correlation (r2 = 0.987) between the predicted and conducted experimental results of urease inhibitory activity. Two new novel polyphenols were identified (luteolin-7-0- rutinoside glycoside derivative [m/z 786] and an unknown compound [m/z 651]) through LC-MSPDA analysis. Likewise, simulated bioimplant coated with purified polyphenols recorded a satisfactory urease inhibitory activity. Conclusion: A correlated result of urease inhibition, growth inhibition against clinically significant bacterial pathogens, and in vitro struvite stone dissolution strongly support the efficacy of renoprotective effect of C. limon seeds.