Abamectin induced brain and liver toxicity in carp: The healing potential of silybin and potential molecular mechanisms.

Abamectin (ABM) abuse contaminated aquatic environment and posed a potential threat to fish health as well as public safety. Silybin (SIL), a flavonoid, has been widely used as a novel feed additive to promote fish health. This research was to explore the potential antagonistic mechanism between ABM and SIL on brain and liver toxicity was investigated in common carp. Sixty carp were divided into four groups at random: the Control group, the SIL group, the ABM group, and ABM + SIL group. This experiment lasted for 30 d. According to behavioral observation, the detection of levels of acetylcholinesterase (AchE), iron, and mRNA expression levels of blood-brain barrier (BBB) related tight junction proteins (ZO-1, Claudin7, Occludin, MMP2, MMP9, and MMP13) in brain tissues, it was found that SIL relieved neurobehavioral disorders caused by ABM-induced BBB destruction in carp. H&E staining showed SIL mitigated nerve injury and liver injury caused by ABM. Oil Red O staining and liver-related parameters showed that SIL alleviated hepatotoxicity and lipid metabolism disorder caused by ABM exposure. Furthermore, this work also explored the specific molecular mechanism of SIL in liver protection and neuroprotection. It was shown that SIL lowered ROS levels in liver and brain tissues via the GSK-3β/TSC2/TOR pathway. Simultaneously, SIL inhibited NF-κB signaling pathway and played an anti-inflammatory role. In conclusion, we believed that SIL supplementation has a protective effect on the brain and liver by regulating oxidative stress and inflammation.