Methods: 2, 2 diphenyl- 1- pycryl hydrazyl (DDPH) free radical scavenging assay was used to calculate antioxidant activity. The hepatoprotective properties of MTPL, MTPS and MTPF (methanolic extracts of T. procumbens Leaves, Stem, flower) and hepatotoxicity of isoniazid-rifampicin in vitro on Chang liver cells as percentage cell viability was calculated by MTT assay. The animals were divided into 6 groups (6 rats in each), treated for 14 days. Group-1 (control), normal saline (1ml/Kg) P.O. Group-2 (Toxic), INH+RMP (50 & 100mg/kg) i. p. after day 14th. Group-3 (positive) Silymarin-suspension 200mg/Kg p. o. and toxin same as group-2. Group-4, 5 & 6 received MTPL, MTPS and MTPF (500mg/Kg) p. o. and toxin similar as group 3. After treatment, blood was collected for biochemical estimation and liver was dissected for histological examination.

Results: In DPPH assay, MTPL and MTPS demonstrated strong antioxidant property (34.52 ± 0.67µg/mL and 33.14 ± 0.76µg/mL); INH+RMP has significant effects on cell viability, MTPL, MTPS and MTPF were not cytotoxic. Significant elevation of serum liver enzyme were observed (P<0.001) along with considerable decrease of SOD, CAT levels in toxic group. Treatment groups compared with standard drug Silymarin prohibited rise in liver enzymes level while increased SOD, CAT and TP (P> 0.05) level. Histopathological profile was helpful to support biochemical parameters.

Conclusion: INH+RMP induce liver injury. MTPL recorded more hepatoprotective potential as compared to MTPS and MTPF.