Thymol dietary supplementation mitigates microplastic-induced hematological disturbances, oxidative stress, immunosuppression, gene dysregulation, and histopathological alterations in Nile tilapia.

Toxic effects of MPs and Up Grade® herbicide on the Nile tilapia (Oreochromis niloticus): Oxidative stress, immune responses, and histopathological investigations

Exposure to sub-lethal concentrations of UPGR and PE-MPs individually and in combination for 15 days induce oxidative stress, immunotoxic impairments and cause severe histological changes in the gills, intestines and testes of O. niloticus.

Recuperative efficacy of Amphora coffeaeformis-enriched diet on immunotoxicological, hematobiochemical alterations, oxidative stress, proinflammatory genes disorder, and histopathological changes caused by cypermethrin toxicity in Nile tilapia.

This work investigates the potential protective effects of the diatom Amphora coffeaeformis as a feed additive against the deleterious effects (primarily on immune organs) of cypermethrin (CYP) in Nile tilapia, Oreochromis niloticus, with respect to hematology, immune/antioxidant parameters, biochemical indices, proinflammatory and apoptotic regulatory genes, and tissue architecture. For subacute exposure, a total of 240 healthy O. niloticus (30 ± 2.5 g) were allocated into four groups in triplicate (20 fish/replicate). The control and AMP groups were fed a basal diet and a 5% A. coffeaeformis supplement, respectively. The CYP and AMP+CYP groups were fed a basal diet and a 5% A. coffeaeformis supplement, respectively, and exposed to sublethal concentrations of CYP for 21 days. A substantial decrease in hematological indices (RBCs, Hb, PCV, and WBCs) and immune/antioxidant parameters (phagocytic and respiratory burst activities, GSH, TAC, SOD, and CAT) was observed with CYP exposure. Additionally, notable increases were observed in serum levels of hepatorenal indicators (ALT, AST, ALP, urea, creatinine, and uric acid), the lipid profile (cholesterol and triglycerides), the MDA lipid peroxidation biomarker, and pro-inflammatory IL1β and apoptotic Cas3 gene expression. Furthermore, hepatic and splenic tissues were severely affected by CYP exposure. Feeding CYP-exposed fish an A. coffeaeformis diet significantly improved hematological indices, immune/antioxidant status, hepatorenal function, and lipid profile, and decreased expression of the stress protein HSP70 and pro-inflammatory cytokines (IL1β, TNFα, and CC1- chemokine) and the apoptotic Cas3 gene compared with CYP-exposed fish. Additionally, tissue architecture improved following A. coffeaeformis supplementation. Overall, A. coffeaeformis diets could be enriched as a feed supplement in the O. niloticus diet to alleviate adverse effects on fish health and immune response during CYP exposure.

Nigella sativa oil ameliorates malathion-ınduced toxicity in Nile tilapia: a multi-systemic and molecular evaluation

It is demonstrated that dietary Nigella sativa oil effectively mitigates malathion-induced toxic effects and offers a comprehensive insight into the protective mechanisms of black cumin oil in aquaculture.

Toxicological Effects of Polystyrene Microplastics on Growth, Enzymatic Activity, Hematology, and Tissue Integrity in Labeo rohita.

Polystyrene microplastics (PS-MPs) are emerging aquatic contaminants with potential toxicological impacts on fish health and aquaculture sustainability. This study evaluated the dose-dependent effects of PS-MPs on growth performance, enzymatic activity, hematological parameters, behavior, nutrient digestibility, and histopathology in Labeo rohita (Rohu). A total of 180 fingerlings were randomly assigned to three groups: control (0 mg/L), low exposure (50 mg/L), and high exposure (100 mg/L), with triplicate tanks (n = 20 fish per tank) over a 21-day period. Exposure to PS-MPs significantly impaired growth performance, as evidenced by reduced weight gain, increased feed conversion ratio, and decreased survival in the high-dose group (p < 0.05). Alkaline phosphatase (ALP) activity in gill and intestinal tissues declined markedly in a dose-dependent manner, indicating compromised metabolic and absorptive functions. Hematological analysis revealed reduced red blood cell count and hemoglobin concentration, alongside elevated white blood cell count, suggesting anemia and stress-induced immune responses. Behavioral alterations, including reduced feeding efficiency, irregular swimming, and increased bottom-dwelling activity, were more pronounced at higher concentrations. Furthermore, nutrient digestibility coefficients for dry matter, protein, fat, and energy decreased significantly with increasing PS-MP exposure. Histopathological examination confirmed severe structural damage in gill and intestinal tissues, including epithelial lifting, lamellar fusion, necrosis, villi shortening, and inflammation. These findings demonstrate that PS-MPs exert multilevel toxic effects on L. rohita (Rohu), disrupting physiological, biochemical, and structural integrity. Overall, this study highlights the ecological and toxicological risks of microplastic contamination in freshwater systems and underscores the need for mitigation strategies to protect aquatic organisms and aquaculture productivity.

Dietary parsley seed powder attenuates acrylamide-waterborne toxicity hazards on growth, redox status, immunity and gene regulations in Oreochromis niloticus.

This study evaluated the protective role of dietary parsley seed powder (PSP) against acrylamide (ACR) toxicity in Nile tilapia (Oreochromis niloticus). A total of 200 juvenile fish (15.98 ± 0.01 g) were randomly assigned to four dietary groups (0.0, 2.5, 5.0 and 10.0 g PSP/kg diet) and exposed for 56 days to a sublethal ACR concentration (3.46 mg/L). Throughout the experiment, growth performance, blood biochemical indices, immune responses, oxidative stress biomarkers, digestive enzyme activities, histopathology and hepatic gene expression were thoroughly assessed. The results revealed that PSP supplementation, particularly at 10.0 g/kg, significantly improved final body weight, body weight gained, daily weight gain and survival rate (p ≤ 0.05), while reducing feed conversion ratio significantly at 2.5 g/kg (p ≤ 0.001). Moreover, blood AST activity was significantly decreased in the 5.0 and 10.0 g/kg groups (p ≤ 0.01), accompanied by significantly elevated total protein and albumin (p < 0.01), and reduced uric acid and creatinine levels (p ≤ 0.001), indicating hepatoprotective and nephroprotective effects. Additionally, PSP exerted anti-inflammatory and antioxidant benefits, as evidenced by significantly reduced serum tumour necrosis factor-α (TNF-α) levels (p ≤ 0.001) and increased glutathione (GSH) concentration (p ≤ 0.05), especially in the 10.0 g/kg group. Digestive enzymes (amylase and pepsin) exhibited a significant increase at all PSP levels (p ≤ 0.05 or 0.01), with the highest levels observed in the DP3 group (10.0 g PSP/kg diet). Histopathological evaluation indicated a dose-dependent attenuation of intestinal and hepatopancreatic alterations with increasing PSP levels, as evidenced by reduced lesion severity, decreased necrotic changes and better preservation of tissue architecture. Furthermore, gene expression analysis revealed significant downregulation of cysteine-aspartic acid protease-3 (caspase-3) and tumour necrosis factor-alpha 2 (tnf-2α) genes (p ≤ 0.01) and upregulation of insulin-like growth factor 1 (igf-1) and growth hormone (gh) (p ≤ 0.01) genes in the 10.0 g/kg group, indicating enhanced growth and cellular resilience. In conclusion, dietary PSP at 10.0 g/kg significantly alleviates ACR toxicity by enhancing physiological, biochemical, immunological and molecular responses in Nile tilapia.

Efficacy of dietary Artemisia annua against chronic carbendazim exposure in Nile tilapia: growth, antioxidant capacity, intestinal morphology, inflammatory/apoptotic genes