Ameliorative effect of selenium yeast supplementation on the physio-pathological impacts of chronic exposure to glyphosate and or malathion in Oreochromis niloticus

Abstract

Background: Pesticide exposure is thought to be a major contributor to living organism health deterioration, as evidenced by its impact on both cultured fish species and human health. Commercial fish diets are typically deficient in selenium (Se); hence, supplementation may be necessary to meet requirements during stress. Therefore, this study was conducted to investigate the protective role of selenium yeast (SY) supplementation for 60 days against the deleterious effects of glyphosate and or malathion chronic toxicity at sublethal concentrations in Oreochromis niloticus .

Methods: Two hundred and ten fish were divided into seven groups (n = 30/group) as follows: G1 (negative control); G2 (2 mg L^{- 1} glyphosate); G3 (0.5 mg L^{- 1} malathion); G4 (glyphosate 1.6 mg L^{- 1} and malathion 0.3 mg L^{- 1}); G5 (glyphosate 2 mg L^{- 1} and SY 3.3 mg kg^{- 1}); G6 (malathion 0.5 mg L^{- 1} and SY 3.3 mg kg^{- 1}); and G7 (glyphosate 1.6 mg L^{- 1}; malathion 0.3 mg L^{- 1} and SY 3.3 mg kg^{- 1}).

Results: Results revealed significant alteration in growth performance parameters including feed intake (FI), body weight (BW), body weight gain (BWG), specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER). G4 has the highest documented cumulative mortalities (40%), followed by G3 (30%). Additionally, the greatest impact was documented in G4, followed by G3 and then G2 as severe anemia with significant thrombocytopenia; leukocytosis; hypoproteinemia; increased Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST), urea, and creatinine, as well as malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Considering the previously mentioned parameters, selenium yeast (Saccharomyces cerevisiae) (3.3 mg kg^{- 1} available selenium) mitigated the negative impact of both the agrochemicals, whether exposed singly or in combination, in addition to their antioxidative action.

Conclusions: In conclusion, our study found that organophosphorus agrochemicals, single or combined, had negative impacts on Oreochromis niloticus regarding growth performance, biochemical and hematological changes in the serum, as well as induced oxidative damage in liver and kidney tissues. Supplementation of SY at the rate of 3.3 mg kg^{- 1} diet (2.36 mg kg^{- 1} selenomethionine and 0.94 mg organic selenium) ameliorated the fish performance and health status adversely affected by organophosphorus agrochemical intoxication.

Keywords: Glyphosate; Hematology; Malathion - Oreochromis niloticus; Oxidative stress; Performance; Selenium yeast.

Fig. 1

Body weight gain (BWG); body weight (BW) and Feed intake (FI) among the different treated groups during the different experimental periods. Means with different superscripts are statistically different at p ≤ 0.001(BWG) and at p ≤ 0.05 (BW). A 30th day of experiment; B 45th day of experiment; C 60th day of experiment; D Average mean

Fig. 2

Specific Growth Rate (SGR); Feed Conversion Ratio (FCR) and Protein Efficiency Ratio (PER) among the different treated groups during the different experimental periods. Means with different superscripts are statistically different at p ≤ 0.001and at p ≤ 0.05 (FCR during 60th day). A different experimental periods; B Average mean

Fig. 3

Cumulative mortalities among different treatments during the experimental period. Means with different superscripts are statistically different (P ≤ 0.0001)

Fig. 4

Principle component analysis of Glyphosate and /or Malathion intoxication with hematological; biochemical and growth performance parameters in Oreochromis niloticus. Data were extracted by principal component analysis (PCA) and rotated through Varimax with Kaiser Normalization. Explained variance % was 53.73, 12.35, 10.1, 7.6 and 4.7% while Cumulative % was 53.73, 66.1 and 76.16, 83.8 and 88.5% for components (PC1, PC2, PC3, PC4 and PC5, respectively). Positive loading values in PC1 were represented by green upward arrows, while the red downward arrows represented negative loading

Fig. 5

Signs of anemia in groups exposed to agrochemicals. A Black arrows indicated anemic pale fish with pale fins due to reduction in RBCS and Hb content., red arrows represent dark pigmentation. B Postmortem examination showed pale liver and congested gall bladder