Diuretic Activity of Ethanol Extract of Piper attenuatum Leaves Might Be Due to the Inhibition of Carbonic Anhydrase Enzyme: An in vivo and in silico Investigation

Background: Ayurvedic system of medicine is well established for prevention and treatment of renal problems. There are vast number of medicinal plants mentioned in Ayurvedic system of medicine including Piper attenuatum Buch.-Ham. ex Miq. (P. attenuatum) are known to exhibits diuretic properties. Objective: To investigate possible mechanism and diuretic activity of ethanol extract of Piper attenuatum leaves. Methods: Present study reports the diuretic efficacy of P. attenuatum in animal model. Further, study pertaining to phytochemical and analytical investigation followed by effectiveness of bioactive compounds from P. attenuatum against human carbonic anhydrase (hCA) enzyme using molecular docking tool. Results: During phytochemicals screening, several groups of compounds such as amides, terpenoids, proteins, flavonoids, and glycosides have been identified. Further, high-performance thin-layer chromatography (HPTLC) reveals presence of seven spots detected after derivatization with anisaldehyde sulphuric acid. Outcome of study reveals significant diuretic action for both 200 and 400 mg/kg/bw of ethanol extract of P. attenuatum leaves. Interestingly, molecular docking analysis demonstrated greater binding affinity of compounds such as Cepharadione A, Norcepharadione B, Galbelgin, Crotepoxide, and Pipoxide chlorohydrin out of total 23 studied compounds against hCA isoforms (a key biomarker for diuretic) and score is comparable with standard drug Acetazolamide. Conclusion: It was concluded from the present studies that ethanol extract of P. attenuatum leaves exhibits significant diuretic activity. The activity may be correlated due to presence of Cepharadione A, Norcepharadione B, Galbelgin, Crotepoxide, and Pipoxide chlorohydrin as key component responsible for inhibition of hCA isoforms.