[Lithagogue effects of Pyrrosia lingua from Guizhou province on experimental renal calculus in rats].

To screen the active fractions with lithagogue effects of Pyrrosia lingua from Guizhou province and preliminarily investigate its mechanism. The rats were fed with 1% ethylene glycol and 2% ammonium chloride to establish the nephrolithiasis models, which were used to evaluate thelithagogue effects of different polar fractions of P. lingua from Guizhou province. The level of urinary calcium and oxalic acid in urine, renal calcium, oxalic acid, superoxide dismutase (SOD), catalase(CAT) and malondialdehyde (MDA) in renal tissues,as well as crystalline deposit and lithogenesis in renal tissues and the levels of creatinine(Cr) and blood urea nitrogen (BUN) in the serum were detected. The effective compounds were inferred from the analysis of active fractions extract based on LC-MS technology. Petroleum ether fraction and dichloromethane fraction of P. lingua from Guizhou province can reduce renal oxalic acid and renal calcium concentration, increase urinary oxalic acid and urine calcium, with significant inhibitory effect on the formation of renal calculus in rats, significantly increase SOD and CAT activities in renal tissues, and significantly reduce MDA levels. LC-MS analysis showed that the caffeine, citric acid and tartaric acid among the compounds from petroleum ether fraction and dichloromethane fraction had lithagogue effects. Both the petroleum ether fraction and dichloromethane fraction of P. lingua from Guizhou province showed good effect on prevention and treatment of calculus in middle dose groups, and the mechanism may be associated with antioxidation, reducing calcium oxalate crystal deposition, and promoting calcium oxalatecrystal release, in addition, caffeine, citric acid and tartaric acid had lithagogue effects.