Dietary Spirulina platensis alleviates sumithion-induced growth suppression, oxidative and immune stress in Nile tilapia (Oreochromis niloticus)

Pesticides use in agriculture and aquaculture operation has become a cornerstone for enhancing global food security but generating physiological distress in non-target organisms including fish. This study aimed to neutralize the detrimental effects of an organophosphorus pesticide sumithion (also named fenitrothion) by supplementing Spirulina platensis in commercial diet. This study evaluated the efficacy of Spirulina additives in mitigating sumithion originated hemato-toxicity, growth suppression, oxidative and immune stress in Nile tilapia ( Oreochromis niloticus ). Twenty fish were allotted to four triplicated treatments for six weeks such as Control (without test substances), Sumithion (0.3 mg/L), Spirulina (50 g/kg feed), and the combined group abbreviated as Sum + Spirulina (sumithion 0.3 mg/L + Spirulina 50 g/kg feed). At the termination of the experiment, fish were sampled, growth, blood, oxidative and immune stress markers were evaluated. The growth performances in terms of weight gain (WG) and specific growth rate (SGR) decreased significantly in sumithion group. Besides, significant alterations in blood profiles were also observed such as lower hemoglobin level (g/dL) and higher glucose level (mg/dL), increased erythrocytic cellular and nuclear anomalies in sumithion group. Oxidative and immune stress markers were also affected; SOD downregulated while immune-related genes TNF-α, IFN-γ, and IL-1β experienced both up and downregulated in fish subjected to sumithion. Moreover, sumithion caused significant damage to the histoarchitecture of intestine. Nevertheless, Spirulina inclusion in the feed remarkably restored the suppressed growth, altered blood profiles, and expression of oxidative and immune-related genes in the liver, histomorphology of gut instigated by sumithion. These findings indicate substantial repairment of health status of Nile tilapia thereby recommending Spirulina supplementation for amelioration of pesticide affected physiological damage in fish. • Chronic exposure to sumithion produced toxicological effects in Nile tilapia. • Sumithion affected growth, blood, oxidative and immune stress markers. • Inclusion of Spirulina in feed significantly repaired physiological impairments induced by sumithion.