In Vitro and In Vivo Antiurolithic Effect of Betulinic Acid Obtained from Citharexylum mirianthum

The study aimed to investigate the potential antiurolithic effects of extracts, fractions, and betulinic acid (BA) from Citharexylum mirianthum. In vitro analysis involved precipitating calcium oxalate (CaOx) crystals in urine. For in vivo studies, rats were divided into four groups: naive; vehicle; potassium citrate (KC); and BA. Urolithiasis was induced using ethylene glycol and ammonium chloride. After seven days, urine, blood, and kidney tissues were evaluated. The results showed that methanolic extract, hexane, dichloromethane, and ethyl acetate fractions, as well as BA, reduced CaOx crystal formation. In vivo, the vehicle-treated group exhibited reduced urinary volume and Na⁺ excretion, while the BA-treated group showed restored urinary volume and Na⁺ excretion similar to the naive group. BA also significantly reduced urinary monohydrate and dihydrate crystal formation, comparable to the KC group. Other urinary parameters remained unchanged, but plasma analysis revealed decreased Na⁺, K⁺, and Ca²⁺ in the KC group. Renal tissue analysis indicated reduced lipid hydroperoxides and increased reduced glutathione in all urolithiasis groups, with unchanged nitrite levels. BA treatment also improved renal corpuscle morphology. Overall, our findings demonstrate that treatment with BA effectively prevented kidney damage induced by EG+AC ingestion, thereby improving renal function in the urolithiasis model.