Background and Aim: Water pollution caused by industrial waste and human activities has disrupted the reproductive health of aquatic organisms. This study aimed to analyze the effects of water pollution caused by polystyrene particles (PP) on the steroid (estradiol and testosterone) levels and histopathology of male tilapia gonads. In addition, we also analyzed the potential of supplementary feeding to remove and neutralize oxidants. Materials and Methods: Thirty-six tilapia fishes were taken for the study and were divided into 12 groups (n=3), including a control group (fed with commercial pellets only) and groups fed with a mixture of commercial-probiotic pellets (200 mL/kg, 1×108 colony-forming unit [CFU]/mL) and commercial vitamin C pellets (100 mg/kg), respectively. The PP concentrations used for this study were 0, 0.1, 1, and 10 mg/L, and the treatment time was 2 weeks. The testosterone and estradiol concentrations were analyzed by enzyme-linked immunosorbent assay and histopathological analysis of the gonads. Results: Laboratory analysis performed using tilapia fishes showed that exposure to a PP concentration of <74 μm, mixed with feed for 14 days, could decrease estradiol and testosterone levels. Exposure to plastic particles could change the structure, shape, and size of male gonads. It can also affect the spermatogenic cell number and alter the diameter inside the cysts. Originally, plastic particles were believed to reduce the permeability of the cyst membrane, and this damages the membrane or ruptures the cyst. Supplementary feed containing probiotics (200 mL/kg, 1×108 CFU/mL) and vitamin C (100 mg/kg) can ameliorate the impact of PP exposure on steroid levels. The steroid levels increase with a concurrent improvement in cysts and seminiferous tubule structures. Conclusion: Overall, this study indicates that PP concentrations in the aquatic environment negatively affect tilapia reproduction, and this may pose a potential threat to the fish population in freshwater. Provision of supplementary feed containing probiotics and vitamin C may serve as an alternative way to counter the negative impact caused by plastic particles.

Background and Aim: Industrial waste, such as heavy metals, is a major source of water pollution; at high levels, such pollution can reduce river water quality to the extent that it becomes unsuitable for aquaculture of freshwater fish. This study aimed to focus on the effects of copper (Cu) exposure in Nile tilapia (Oreochromis niloticus) and specifically the ability of Lactobacillus-based probiotics supplementation in fish feed to ameliorate damage to gonads and negative effects on red blood cells (RBCs), whole blood cells (WBCs), hematocrit (HCT) levels, hemoglobin (HGB) levels, and malondialdehyde (MDA) levels following such exposure. Materials and Methods: Thirty-two Nile tilapia fish were divided into eight groups: A negative control (without probiotics or Cu), a positive control (with probiotics but without Cu), three treatments with probiotics in feed, and one of three Cu concentrations (0.75, 1.50, or 3.00 mg/L), and three treatments with these three Cu concentrations but without probiotics in feed. The probiotics concentration in feed was 25 mL/kg (1×108 CFU/mL). Feeding was for 15 days, after which the hematological parameters, gonadal (testis) structure, and MDA levels of fish were analyzed. Results: Exposure to Cu significantly (p<0.05) affected fish hematology (decreased HGB, HCT, RBC, and WBC levels) and altered the structure of the testes. However, the addition of probiotics to fish feed significantly (p<0.05) ameliorated these effects on hematology and maintained the histological structure of the gonads. Conclusion: Cu exposure at ≥1.5 mg/L affected the hematologic parameters, gonadosomatic index, MDA levels, and testicular cells and tissue of Nile tilapia. However, probiotics supplementation in fish feed helped ameliorate the negative effects of Cu on these parameters. Thus, the Lactobacillus-based probiotics used in this study were apparently able to neutralize Cu toxicity in Nile tilapia.

Polystyrene nanoplastics (PS-NPs) are result from the degradation of plastic and have diameters ranging from 1 nm to 100 nm. The objective of this study is to provide information on the adverse effects of PS-NPs with in vitro and in vivo analyses of liver injury. An in vitro study was conducted using confocal microscopy, flow cytometry, and MTT test analysis. An in vivo study was conducted to determine apoptosis levels, glucose metabolism gene expressions, liver enzymes, and liver histology. Data were analyzed using GraphPad Prism software 10.2.1. The in vitro study showed the absorption of PS-NPs in the cell cytoplasm, the percentage of apoptosis, 3t3, and the WiDr cell lines’ viability. The in vivo analysis showed that PS-NPs can stimulate liver injuries, such as inducing the elevation of liver enzymes, necrosis, edema, inflammation, and the dilatation of the portal vein diameter. High levels of caspase-3, caspase-9, and Bax were detected, as well as the expression of several genes including PI3K, AKT, PEPCK, GLUT2, and PK. In conclusion, the in vitro analysis showed the detrimental effects of PS-NPs on cells, such as high levels of apoptosis and low cell viability, while the in vivo studies displayed the impairment of liver tissue and disturbances in glucose metabolism regulation.