Tuberculosis (TB) is an airborne infection that requires at least six to nine months treatment. Long term treatment of TB may produce severe toxic effects to organs such as kidney, liver, gastrointestinal and blood vascular systems. The present study was designed to evaluate the nephroprotective effects of Ficus religiosa (peepal plant) stem bark against the toxic effects induced by anti TB drugs rifampicin (RIF) and isoniazid (INH). For this purpose, 40 rabbits were divided into five groups (n=8). Group 1 was kept as control without drugs. Group 2 was given anti TB drugs orally for 28 days while groups 3, 4 and 5 were given silymarin, ethanolic ficus extract, and water ficus extract along with anti TB drugs orally for 28 days respectively. Blood samples were taken before drug administration and at 7^th, 14^th, 21^st, and 28^th days post treatment for biochemical and drug analysis. Kidney tissues were taken for histopathological studies.  Results have indicated that Mean±SEM blood urea nitrogen (BUN) was increased significantly (P˂0.05) in RIF + INH-treated rabbits (45.94±2.15) as compared to control group (27.86±0.22). The administration of silymarin reduced BUN (33.17±1.87) towards normal. The administration of alcohol extract of F. religiosa further reduced this BUN level (32.15±1.67), almost close to normal value while its hydro extract also reduced the BUN level (34.85±2.85) significantly but less than alcoholic extract of F. religiosa and silymarin. Similar findings were found with creatinine. Kidney of RIF + INH-treated rabbits showed severe degree of infiltration in the glomerulas without renal tubular space between the glomerulas when compared to normal group. Drug analysis with HPLC revealed that drug concentration in plasma coincides with the toxicity of RIF and INH.  In conclusion, the alcoholic as well as water extracts of F. religiosa have shown potent nephroprotective effects when administered along with the RIF+INH and have shown results similar to that of silymarin.

Key words: HPLC, Isoniazid, Nephroprotection, Rifampicin, Toxicity