Dietary l-carnitine prevents histopathological changes in tilapia (Oreochromis Niloticus) exposed to
Remedios Guzmán-Guillén1, Ana I Prieto Ortega1, Rosario Moyano2
1Area of Toxicology, Faculty of Pharmacy, University of Sevilla, C/Profesor García González 2, Sevilla, 41012, Spain.
Abstract:
Cylindrospermopsin (CYN) is a cytotoxin highly water-soluble, which is easily taken up by several aquatic organisms. CYN acts as a potent protein and glutathione synthesis inhibitor, as well as inducing genotoxicity, oxidative stress, and histopathological alterations. This is the first study reporting the protective effect of a l-carnitine (LC) pretreatment (400 or 880 mg LC/kg bw fish/day, for 21 days) on the histopathological alterations induced by pure CYN or Aphanizomenon ovalisporum lyophilized cells (400 µg CYN/kg bw fish) in liver, kidney, heart, intestines, and gills of tilapia (Oreochromis niloticus) acutely exposed to the toxin by oral route. The main histopathological changes induced by CYN were disorganized parenchyma with presence of glycogen and lipids in the cytoplasm (liver), glomerulonephritis, glomerular atrophy, and dilatation of Bowman's capsule (kidney), myofibrolysis, loss of myofibrils, with edema and hemorrhage (heart), intestinal villi with necrotic enterocytes and partial loss of microvilli (gastrointestinal tract), and hyperemia and hemorrhage (gills). LC pretreatment was able to totally prevent those CYN-induced alterations from 400 mg LC/kg bw fish/day in almost all organs, except in the heart, where 880 mg LC/kg bw fish/day were needed. In addition, the morphometric study indicated that LC managed to recover totally the affectation in the cross sections of the proximal and distal convoluted tubules in CYN-exposed fish. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 241-254, 2017.
Insights
L-carnitine (LC) pretreatment protected tilapia from the harmful effects of the cyanotoxin cylindrospermopsin (CYN). LC supplementation prevented CYN-induced histopathological damage in multiple organs, demonstrating its protective potential in aquaculture.
Area of Science:
- Aquatic toxicology
- Environmental chemistry
- Fish physiology
Background:
- Cylindrospermopsin (CYN) is a water-soluble cyanotoxin that inhibits protein and glutathione synthesis.
- CYN exposure causes genotoxicity, oxidative stress, and histopathological damage in aquatic organisms.
- Tilapia (Oreochromis niloticus) are vulnerable to CYN contamination in water bodies.
Purpose of the Study:
- To investigate the protective effects of L-carnitine (LC) pretreatment against CYN-induced histopathological alterations in tilapia.
- To determine the efficacy of different LC dosages in mitigating CYN toxicity.
- To assess LC's impact on various organs including liver, kidney, heart, intestines, and gills.
Main Methods:
- Tilapia were pretreated with L-carnitine (400 or 880 mg/kg bw/day) for 21 days.
- Fish were then exposed to pure CYN or Aphanizomenon ovalisporum lyophilized cells (400 µg CYN/kg bw).
- Histopathological examination and morphometric analysis were conducted on liver, kidney, heart, intestines, and gills.
Main Results:
- CYN exposure induced significant histopathological changes in all examined organs.
- LC pretreatment (400 mg/kg bw/day) prevented most CYN-induced alterations.
- Higher LC dosage (880 mg/kg bw/day) was required to protect the heart, and LC fully restored kidney tubule morphology.
Conclusions:
- L-carnitine pretreatment offers significant protection against cylindrospermopsin toxicity in tilapia.
- LC supplementation can mitigate CYN-induced histopathological damage across multiple organs.
- LC is a promising dietary supplement for protecting farmed fish against cyanotoxin exposure.
