CONICET | Buscador de Institutos y Recursos Humanos

Ethnopharmacological relevance: Boldoa purpurascens Cav. (Nyctaginaceae) is a plant species used in traditionalmedicine in Cuba as antiurolithiatic.Aim of the study: The aim of the present investigation was to evaluate the in vitro and in vivo antiurolothiaticactivity of an aqueous extract from the leaves of Boldoa purpurascens.Materials and methods: The aqueous extract from leaves of Boldoa purpurascens was evaluated for antiurolithiaticactivity in vitro and in vivo. In vitro crystallization of calcium oxalate (CaOx) was assessed using a nucleation,aggregation and growth assay. The effects of the extract and of Cystone®, used as a positive control, on the slopeof nucleation and aggregation, as well as on the growth of CaOx crystals, were evaluated spectrophotometrically.The densities of the formed crystals were compared microscopically. In vivo activity was evaluated in an urolithiasismodel in rats, in which kidney stones are induced by ethylene glycol (0.75%) and ammonium chloride(2%) in drinking water for 10 days. Three different experimental doses (100, 200 and 400 mg/kg, p.o.) of theextract and Cystone® were administered for 10 days. After 10 days, various biochemical parameters weremeasured in urine and serum, and histopathological analysis of the kidneys was carried out.Results: The aqueous extract of Boldoa purpurascens inhibited the slope of nucleation and aggregation of CaOxcrystallization, and decreased the crystal density. It also inhibited the growth and caused the dissolution of CaOxcrystals. Cystone® exhibited similar effects. At a dose of 400 mg/kg the extract reduced the concentration of uricacid in urine, as well as the serum concentration of uric acid and creatinine. Histopathologic analysis of thekidneys of the same treatment group revealed reduced tissue damage; the results were almost similar to theuntreated healthy control group.Conclusion: This study indicates that an aqueous leaf extract of Boldoa purpurascens may be effective in theprevention of urinary stone formation, and substantiates the traditional claim.