Unveiling the role of spirulina in the mitigation of sumithion-induced toxicity in Thai pangas, Pangasianodon hypophthalmus

Abstract

Sumithion is an organophosphate insecticide, widely used in aquaculture ponds to eradicate aquatic insect (mainly tiger bugs), typically applied before stocking fish larvae. However, it adversely affects non-target aquatic organisms, particularly fish. This study was conducted to evaluate the potential toxicity of sumithion in Thai pangas (Pangasianodon hypophthalmus) as well as the role of dietary Spirulina platensis in mitigating the toxic effects of sumithion. Over a 42-day trial, a total 240 of striped catfish fingerlings were exposed to four different treatments: control (without Sumithion or Spirulina), sumithion (0.6 mg/L), Spirulina (50 g/kg feed) and combined treatment (sumithion + Spirulina) with three replicates each. Sumithion-treated fish exhibited altered hemato-biochemical indices (hemoglobin and glucose) as well as erythrocyte morphology such as cellular (teardrop, twin, fusion) and nuclear (nuclear bridge, nuclear buds, notch, karyopyknosis) abnormalities. Furthermore, the sumithion-treated fish exhibited a considerable difference in the expression levels of antioxidant genes with down-regulated of SOD, CAT and up-regulated of GPx as well as immune-related genes with up-regulated of MHC-II and IFN-β2 and down-regulated of IL-1β and IFN-α2 compared to control. Moreover, it has been found that Spirulina along with sumithion improves the immunological, anti-oxidative, and physiological conditions of fish. The present study unveiled the implementation of dietary Spirulina to be an effective approach to mitigate sumithion-induced stress and optimize health condition in striped catfish by improving haemato-biochemical index and immune-antioxidant genes expression.