The most potent antilithiatic agent ameliorating renal dysfunction and oxidative stress from Bergenia ligulata rhizome.

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizome of Bergenia ligulata is referred by the Ayurvedic system for the treatment of kidney stone since decades and a few, in vitro and in vivo studies also support it. To identify the main phytochemical constituent(s) responsible for antilithiatic activity of its rhizome.

MATERIALS AND METHODS

In order to identify the most potent antilithiatic metabolite, the crude extract of rhizome was fractionated using in vitro Calcium oxalate (CaOx) crystal growth inhibitory activity guided fractionation followed by its characterization via LC-MS, FTIR and NMR. Further, the antioxidant potential of purified molecule was assessed using in vitro assays (FRAP and H2O2 scavenging). In vivo activity of the metabolite was evaluated in hyperoxaluric rats given 0.4% ethylene glycol (EG) and 1.0% ammonium chloride (NH4Cl) for 9 days.

RESULTS

Activity guided fractionation led to the isolation of most potent antilithiatic metabolite from the rhizome of Bergenia ligulata and spectroscopic analysis revealed it as bergenin. Bergenin showed reducing ability and H2O2 scavenging activity comparable with commercially available anitioxidant, α-tocopherol. At a dose of 10mg/kg body weight of the treated rat, it protected against deleterious effects of lithogenic treatment including weight loss, impaired renal function and oxidative stress, manifested as increased malondialdehyde, reduced redox ratio and decreased antioxidant enzyme activities in the kidneys of hyperoxaluric rats. The creatinine clearance and kidney damage were more improved by bergenin as compared to crude extract of rhizome.

CONCLUSIONS

Since, bergenin maintained oxidant/antioxidant balance in hyperoxaluric rats, thus mechanistic insight of its antilithiatic activity was attributed to the antioxidant capability of bergenin. The results of the present study provide significant evidence that bergenin is an active component present in the rhizome of Bergenia ligulata for managing CaOx calculi.