Orthosiphon grandiflorum has a protective effect in a calcium oxalate stone forming rat model

This study amied to investigate the effects of Orthosiphon grandiflorum on the renal tubular cell injury induced by oxalate and the inhibitory effects of O. grandiflorum on urinary deposit formation in an animal model and compared the results with those from a potassium citrate treatment. Rats were divided into three groups: an untreated stone-forming group, an O. grandiflorum-treated stone-forming group and a potassium citrate-treated stone forming group. Ethylene glycol (0.5%) was administered to the rats during the last week, and vitamin D3 (0.5 mu m) was force fed to induce hyperoxaluria and kidney calcium oxalate crystal deposition. Twenty-four hour urine samples were collected before and after inducing crystal deposits. Rats were killed and both kidneys were harvested after 3 weeks. Bisected kidneys were examined under a polarized light microscope to determine the number of crystals. The renal tissue superoxide dismutase and catalase levels were measured by Western blot. Oxidative stress was examined by 8-OHdG immunohistofluorescence. O. grandiflorum and potassium citrate have the ability to alkalinize urine. Among all groups, the number of crystal deposits and the level of 8-OHdG staining decreased significantly in the O. grandiflorum-treated stone forming group, as compared to the other groups. Superoxide dismutase and catalase levels also increased significantly in the O. grandiflorum-treated stone-forming group, as compared with the untreated stone-forming group. The results indicate that O. grandiflorum has a significant inhibitory effect on crystal deposition in the calcium oxalate-stone-forming rat model.