Tannic acid ameliorates arsenic trioxide-induced nephrotoxicity, contribution of NF-κB and Nrf2 pathways

BACKGROUND AND PURPOSE: Tannic acid (TA), a group of polyphenolic compounds, has multiple anticancer, antimutagenic, antioxidant and anti-inflammatory activities. However, the effects of TA on arsenic trioxide (ATO)-induced nephrotoxicity are still relatively unknown. This study investigated the protective effects and potential mechanisms of TA on ATO-induced nephrotoxicity in rats. METHODS: Rats were intragastrically administered TA with concurrent ATO infused intraperitoneally over 10 days. Renal morphology changes were observed through light microscopy. The levels of antioxidants and pro-inflammatory factors were measured in the serum and renal tissue, respectively. Further, expression of B-cell lymphoma-2, B-cell lymphoma-extra large, p53, and Bcl-2-associated X protein were measured using an immunohistochemical method. The protein expression of nuclear factor kappa B (NF-kappaB), nuclear factor-erythroid-2-related factor 2 (Nrf2), and kelch-like ECH-associated protein 1 (Keap1) were measured by Western blot. RESULTS: The data showed that ATO exposure significantly increased the serum nephritic, oxidative stress, apoptosis and inflammatory markers in the renal tissue of rats. Conversely, pretreatment with TA reversed these changes. Furthermore, TA treatment caused a significant decrease in NF-kappaB expression (P < 0.05), while increasing Nrf2 and Keap1 expressions (P < 0.05). CONCLUSION: TA ameliorates ATO-induced nephrotoxicity, which is related to the inhibition of oxidative stress, inflammation and apoptosis, potentially through the NF-kappaB/Nrf2 pathway.