Protective effects and molecular mechanisms of baicalein on thioacetamide-induced toxicity in zebrafish larvae

Baicalein is a flavonoid that is widely found in plants. Studies have shown that baicalein has anti-inflammatory, anti-cancer, and liver-protective effects. However, the effects of baicalein on TAA-induced toxicity and the underlying molecular mechanisms in zebrafish larvae are still unknown. Here, we investigated the effects of baicalein on liver development and its anti-inflammatory effects in zebrafish larvae. The results showed that baicalein has significant anti-embryonic developmental toxicity and significant antioxidant and anti-inflammatory capabilities in TAA-induced zebrafish larvae and promotes liver development and cell proliferation, reduces the expression of apoptotic proteins, and induces the expression of anti-apoptotic proteins. At the molecular level of TAA-treated zebrafish larvae, there was a decrease in the relative expression levels of mRNAs of three subfamilies, P38, ERK1, and ERK2, of the MAPK-signaling pathway and of the products of peroxisome proliferator-activated receptor (PPAR)α. Compared with TAA-treated zebrafish larvae, zebrafish larvae treated with baicalein showed an increase in the relative expression levels of P38, ERK1, and ERK2 mRNAs and the downstream products of PPARα. When MAPK signal inhibitor (SB203580) was added, it was found that liver development was inhibited and baicalin had no protective effect on TAA induced hepatotoxicity in zebrafish larvae. The results showed baicalein can protect the zebrafish larvae against toxicity induced by TAA through MAPK signal pathway. Several molecular mechanisms discovered in this study may help in the development of new drugs.