Dietary α-lipoic acid can alleviate the bioaccumulation, oxidative stress, cell apoptosis, and inflammation induced by lead (Pb) in Channa argus

This study aims to evaluate the effects of dietary alpha-lipoic acid (alpha-LA) on bioaccumulation, oxidative stress, apoptosis, and inflammation in Channa argus after 28 d of lead (Pb) exposure. A total of 300 fish were divided into five groups: the first group was the control group and the other four groups were exposed to waterborne Pb (800 ppb) and fed alpha-LA diets supplemented with 0, 300, 600, and 900 mg/kg. The results demonstrated that dietary alpha-LA effectively reduced the Pb accumulation in the liver, kidney, gill, intestine, and muscle of C. argus after exposure to Pb. Meanwhile, dietary alpha-LA reversed alterations in the biochemical parameters (Alanine aminotransferase (ALT), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), blood urea nitrogen (BUN), cortisol (COR), and creatinine (CRE)) and immunity parameters (myeloperoxidase (MPO), complement 3 (C3), lysozyme (LYS), complement 4 (C4), C-reactive protein (CRP), and immunoglobulin M (IgM)) in the serum of fish caused by Pb. Pb-induced reduction of antioxidant enzyme activities (Catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-Px)) was inhibited by dietary alpha-LA. And malondialdehyde (MDA) and protein carbonyl (PC) content exhibited an opposite trend. Meanwhile, dietary supplemented with alpha-LA was found to relieve Pb-induced oxidative stress by downregulating Keap1 mRNA expression levels and upregulating the expression levels of CAT, nuclear factor erythroid 2-related factor 2 (Nrf2), GSH-Px, and Cu/Zn SOD. Furthermore, alpha-LA supplementation reversed Pb-induced upregulation of pro-inflammatory genes (interleukin (IL)-6, IL-1 beta, tumor necrosis factor alpha (TNF-alpha), and nuclear factor kappa B (NF-kappa B)), Pro-apoptotic genes (Bcl-2-associated X (Bax), caspase (Cas)-3, and tumor protein p53 (p53)) and Hsp70, and downregulation of anti-inflammatory genes (IL-10, inhibitor of kappa B alpha (I kappa B alpha), and transforming growth factor beta (TGF-beta)) and anti-apoptosis gene (B-cell lymphoma-2 (Bcl-2)). Overall, dietary alpha-LA supplementation could enhance the innate immunity and antioxidant capacity of fish, attenuating the Pb accumulation, and cell apoptosis after being exposed to Pb. Furthermore, dietary alpha-LA could relieve Pb-induced inflammatory response and oxidative stress of fish via regulating NF-kappa B and Nrf2 signaling, respectively.

Automated summary

The study found that dietary alpha-lipoic acid can effectively reduce lead accumulation in Channa argus, reverse Pb-induced alterations in biochemical and immunity parameters, inhibit Pb-induced reduction in antioxidant enzyme activities, and relieve Pb-induced inflammatory response and oxidative stress by regulating NF-kappa B and Nrf2 signaling pathways.