Modulatory role of L-carnitine against microcystin-LR-induced immunotoxicity and oxidative stress in common carp

Abstract

Microcystin-LR (MCLR), one of the most popular microcystins (MCs) found in many field water bodies around the world, poses great health risks to animals and humans. In the present study, healthy common carp (initial weight 24.8 ± 2.3 g) were randomly assigned to five groups. Group I was fed on normal diet as control. Group II was maintained on normal diet and received MCLR intraperitoneal injection (150 μg kg BW). Common carp in groups III, IV, and V were daily pretreated with L-carnitine (LC) at doses of 0.5, 1.0, and 2.0 g kg of the diet for 4 weeks prior to MCLR intraperitoneal injection. The results showed that MCLR alone led to a significant downregulation in immune response, including serum complement C3, lysozyme, and bactericidal activity. However, oxidative stress response: catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and lipid peroxidation (LPO) levels were significantly increased. Similarly, gene expressions of inflammatory IL-1β, TNF-α, IFN I, and heat shock proteins (HSP70 and HSP90) were also upregulated after challenged with MCLR. However, LC pretreated group caused a significant elevation in immune response (C3, lysozyme, and bactericidal activity) and gene expressions of inflammatory IL-1β, TNF-α, IFN I, and heat shock proteins (HSP70 and HSP90) after MCLR stress. Antioxidant activities (CAT, SOD, GSH, GPx, and LPO) were returned to background levels at 96 h after MCLR challenge. Strikingly, LC supplementation at 2.0 g kg has been considered the optimum for common carp since it exhibited enhancement of immune response and antioxidant activity over the level 0.5 and 1.0 g kg, and even better than that of control level. It was concluded that LC as a functional feed additive significantly inhibited the progression of MCLR-induced immunotoxicity and oxidative stress in common carp.

Response of Macrobrachium rosenbergii to Vegetable Oils Replacing Dietary Fish Oil: Insights From Antioxidant Defense

“…It is postulated that proinflammatory cytokines production could be induced by oxidative stress which was caused by fish oil (Naik and Dixit, 2011), and the lipid peroxidation could be the main reason of the oxidative stress. Similar results were also found in common carp (Cyprinus carpio) (Chen X. M. et al, 2017), large yellow croaker (Larmichthys crocea) , and rat (Rattus norvegicus) (Sanders et al, 2004). Additionally, considerable research supports that n-3 PUFA can induce lipid peroxidation (Pupe et al, 2002;Muralidhar et al, 2004).…”

Effects of dietary terrestrial oils supplemented with l-carnitine on growth, antioxidant capacity, lipid metabolism and inflammation in large yellow croaker (Larimichthys crocea)

“…The mRNA expression of anti-inflammatory genes (il-10 and arg-1) was increased in fish fed the diet with the 75 % TOC compared with 75 % TO. Previous studies have demonstrated that dietary L-carnitine can improve the immunity and disease resistance of juvenile narrow clawed crayfish (Astacus leptodactylus leptodactylus) (66) , black carp (Mylopharyngodon piceus) (67) and common carp (Cyprinus carpio L.) (68) . L-Carnitine exerted protective effects by inhibiting the generation of ammonia and xenobiotics in rat hepatocytes (69) .…”

Determination of microcystin-LR, employing aptasensors

“…Apart from the liver, the testis is another target organ for MC-LR; its presence not only disrupts motility and morphology of sperm but also alters male hormone levels (Lone et al 2015;Zhang et al 2017a). Moreover, immunotoxicity (Chen et al 2017), genotoxicity (Zegura 2016), and developmental toxicity (Qi et al 2016) associated with this cyanotoxin has been investigated.…”