Urease Inhibitory Evaluations of Crude Extracts and Various Fractions of Nicotiana tabacum L.

Abstract

Natural products are still a good source for the identification of bioactive compounds that have great therapeutic potential. In the current research, the authors intended to examine the urease inhibitory activity of Nicotiana tabacum L. root extracts and solvent fractions in the search of a natural urease inhibitor substitute to synthetic urease inhibitors. Methanol was used as crude extract and n-hexane, chloroform, ethyl acetate, methanol, and butanol all were used as fractions. The urease inhibitory activity was known by the use of indophenol method by using jack bean urease as the source of enzyme and thiourea as the standard inhibitor. The butanol extract was the most potent with 88.01% inhibition and an IC50 value of 33.04 +1.35 ug/mL and then the methanol fraction (82.76% inhibition and an IC50 of 38.67 +1.40 ug/mL). Ethyl acetate fraction was moderately active (49.09%), as compared to the hexane and chloroform fractions that had a relatively low level of inhibition (30.32, and 35.87, respectively). These findings show that solvent polarity has a significant influence on the extraction of bioactive phytoconstituents that give urease inhibition activity, with polar solvents extracting more effective inhibitors. The high activity of the butanol and methanol fractions could be explained by the fact that phenolics, flavonoids, alkaloids, and other secondary metabolites that can chelate nickel ions at the active site of the enzyme were present. These results may indicate that N. tabacum root contains an excellent source of natural urease inhibitors that have therapeutic potential in treating urease related pathologies like peptic ulcers, urease related infections of the urinary tract and hepatic disorders. To isolate and characterize the active constituents and investigate their pharmacological significance, further bioassay-directed fractionation, molecular docking and in vivo investigations are justified.