Astragalus membranaceus polysaccharides modulate growth, hemato-biochemical indices, hepatic antioxidants, and expression of HSP70 and apoptosis-related genes in Oreochromis niloticus exposed to sub-lethal thallium toxicity. Issue 118 (November 2021)

• Record Type: Journal Article
• Authors: Farag, Mayada R.; Alagawany, Mahmoud; Khalil, Samah R.; Moustafa, Amr A.; Mahmoud, Hemat K.; Abdel-Latif, Hany M.R.
• Is Part Of: Fish & shellfish immunology. Issue 118(2021)
• Page Start: 251
• Page End: 260
• Publication Date: 2021-11
• Subjects: Aquaculture -- Feed supplements -- Antioxidants -- Amelioration -- Genes; ALT Alanine transaminase -- AST Aspartate transaminase -- CAT Catalase -- FBW Final body weight -- FCR Feed conversion ratio -- FI Feed intake -- GSH Reduced glutathione -- HSP70 Heat shock protein 70 -- LC50 Median lethal concentration -- MDA Malondialdehyde -- p53 Tumor suppressor gene -- SGR Specific growth rate -- SOD Superoxide dismutase -- WG Weight gain; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2021.09.009
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: A 60-day experiment was performed to assess the efficacy of dietary Astragalus membranaceus polysaccharides (ASP) in attenuation of sub-lethal thallium (Tl) toxicity in Nile tilapia. Six experimental groups (in triplicates) were designed where a fish group was raised in clean water and fed basal diet and served as control (CONT), two groups were fed the basal diet supplemented with 0.15% and 0.30% ASP (ASPL and ASPH), Tl-intoxicated group exposed to 1/10 of 96-h LC50 (= 41.9 μg/L), and two other groups were fed 0.15% and 0.30% ASP and concomitantly exposed to 41.9 μg Tl/L (ASPL-Tl and ASPH-Tl). At the end of the experiment, fish behavioral responses, clinical signs, survivability, growth, whole-body composition, intestinal digestive enzymes, serum biochemical parameters, hepatic antioxidative biomarkers, and transcription of stress and apoptosis genes were assessed. Results showed that the whole-body composition, intestinal α-amylase and protease enzymes, serum AST and blood urea levels, and hepatic GSH were not significantly different among groups ( P > 0.05). The Tl-intoxicated fish group was off food, had darkened skin, showed restlessness and hyperexcitability, and high mortalities. FBW, WG, SGR and FI were significantly decreased alongside increase FCR in the Tl-exposed group. Tl exposure caused significant increases ( P < 0.05) in intestinal lipase enzyme and serum indices such as ALT, creatinine, total cholesterol, triglycerides, glucose, and cortisol levels. Moreover, a significant decreases in hepatic CAT and SOD enzyme activities and significant increases in hepatic MDA contents were also noticed ( P < 0.05). Furthermore, Tl exposure induced significant upregulation of hepatic HSP70 and apoptosis-related genes ( p53 and caspase 3 ). Interestingly, dietary supplementation with ASP in ASPL-Tl and ASPH-Tl groups modulated the parameters mentioned above but still not reached the CONT values. Altogether, this study suggests that ASP could be beneficial in the modulation of sub-lethal Tl toxicity effects in Nile tilapia. Additionally, we can conclude that using natural feed supplements such as ASP in aquafeed might be necessary for maintaining the overall health performances of Nile tilapia. Highlights: ⁃ Sub-lethal Thallium (Tl) induced growth retardation, alterations of the hepato-renal functions, and oxidative stress injury in Nile tilapia ⁃ Sub-lethal Tl exposure increased mRNA expression levels of HSP70, p53, and caspase 3 genes in hepatic tissues of Nile tilapia ⁃ Astragalus membranaceus polysaccharides (ASP) attenuated changes in serum biochemical parameters and alleviated oxidative stress in Tl-exposed fish ⁃ Dietary ASP modulated the expression of HSP70, p53, and caspase 3 genes Tl-exposed Nile tilapia ⁃ The findings approved the protective efficacy of ASP as a promising feed supplement to fish.