Dietary teprenone enhances non-specific immunity, antioxidative response and resistance to hypoxia induced oxidative stress in Lateolabrax maculatus

Abstract

Persistent hypoxic or low-oxygen conditions in aquatic systems are becoming more frequent worldwide, causing large-scale mortalities to the aquaculture animals. Hence, it would be of great benefit to search for natural compounds that are clinically safe, yet able to induce host health and antioxidant defence system. In the experiment, Lateolabrax maculatus were fed with ketone compound teprenone and subsequently exposed to hypoxia condition. Afterwards, the effect of teprenone on the antioxidative response, non-specific immunity and hypoxia induced oxidative stress were investigated. We found that dietary supplementation of teprenone at 200 mg/kg (HT200), 400 mg/kg (HT400) and 800 mg/kg (HT800) significantly increase the total antioxidant capacity (T-AOC) during hypoxia stress. While, lower values of malondialdehyde (MDA) content, an indicator of oxidative stress, were recorded in teprenone supplemented groups. In addition, upregulation of non-specific immune parameters including lysozyme (LZM), Hsp70 and Hsp90 was observed in L.maculatus. We further demonstrated that teprenone supplementation protects L.maculatus from hypoxia and oxidative stress generated apoptosis. The pro-apoptotic signalling molecules, i.e., cytochrome C (CtyC), caspase-9 and caspase-3 production were significantly decreased in response to teprenone supplementation during the hypoxia stress. In contrast, the anti-apoptotic response, BCL-2 gene expression, was significantly increased. We have shown that dietary teprenone induces innate immunity and antioxidative response and protects L.maculatus against hypoxia induced-oxidative stress and apoptosis; therefore, suggesting their possible role to manage the stressful condition, in particular, hypoxia stress in aquaculture.