Objective: Sodium nitrite (NaNO2) is used as a color stabilizer and antimicrobial agent in the preservation of cured meat and fish. However, extensive use of this agent in the meat industries increased worries about its detrimental effects on human health. On the other hand, Zataria multiflora (Z. multiflora) is a well-known plant with therapeutic properties in the traditional medicine. Therefore, the present study was conducted to investigate the protective effect of this plant against sodium nitrite induced hepatotoxicity. Materials and methods: 32 male Wistar rats were divided into 4 groups: Control (without any treatment), Sodium nitrite (350 mg/kg NaNO2 by gavage method for 60 days), Nitrite plus Z. multiflora (rats treated with NaNO2 at the same protocol and simultaneously received Z. multiflora extract at 200 mg/kg, ip) and Z. multiflora group (rats treated with Z. multiflora extract at 200 mg/kg, ip). At the end of the study, rats were euthanized and liver tissue samples were taken and studied under microscopy. Also, the serum level of liver function enzymes and antioxidant defense systems were measured. The results were analyzed with ANOVA and P<0.0.5 considered as significant. Results: Results showed that NaNO2 induces liver injuries and altered histo-architecture. Also, NaNO2 significantly altered the biochemical profiles and antioxidant defense parameters of liver. However, treatment with Z. multiflora improved tissue integrity as well as antioxidant defense status and biochemical conditions of liver. Conclusion: Administration of Z. multiflora extract has beneficial effects on the NaNO2 induced both
