Acute Cadmium Toxicity Induced Impairments in the Liver and Kidney of Freshwater Catfish, Heteropneustes fossilis (Bloch)

Cadmium and ketoprofen accumulation influences aquatic ecosystem demonstrated using in-vivo zebrafish model

The growing concern about pollution and toxicity in aquatic as well as terrestrial organisms is predominantly caused due to waterborne exposure and poses a risk to environmental systems and human health. This study addresses the co-toxic effects of cadmium (Cd) and ketoprofen (KPF), representing heavy metal and pharmaceutical discharge pollutants, respectively, in aquatic ecosystems. A 96-h acute toxicity assessment was conducted using zebrafish embryos. The results indicated that high dosages of KPF (10, 15, and 100 µg/mL) and Cd (10 and 15 µg/mL) reduced survivability and caused concentration-dependent deformities such as scoliosis and yolk sac edema. These findings highlight the potential defects in development and metabolism, as evidenced by hemolysis tests demonstrating dose-dependent effects on blood cell integrity. Furthermore, this study employs adult zebrafish for a 42-day chronic exposure to Cd and KPF (10 and 100 µg/L) alone or combined (10 + 10 and 100 + 100 µg/L) to assess organ-specific Cd and KPF accumulation in tissue samples. Organ-specific accumulation patterns underscore complex interactions impacting respiratory, metabolic, and detoxification functions. Prolonged exposure induces reactive oxygen species formation, compromising antioxidant defense systems. Histological examinations reveal structural changes in gills, gastrointestinal, kidney, and liver tissues, suggesting impairments in respiratory, osmoregulatory, nutritional, and immune functions. This study emphasizes the importance of conducting extensive research on co-toxic effects to assist with environmental risk assessments and safeguard human health and aquatic ecosystems.

Dietary Effect of Padina boergesenii on Growth, Immune Response, and Disease Resistance Against Pseudomonas aeruginosa in Cirrhinus mrigala

In the aquatic environment, seaweeds have the potential to be renewable resources. The current study was designed to assess the impact of seaweed Padina boergesenii incorporated into a basal diet at various concentrations. The phytoconstituents of the seaweeds were characterised by gas chromatography-mass spectrometry. Diets were designed to include elevated levels of 0.5%, 2.5%, 4.5%, and 6.5% of seaweed meal. Significant differences in Cirrhinus mrigala fed with P. boergesenii incorporated into the basal diet for 45 days. The growth parameters (weight gain, specific growth rate), biochemical constituents, and immunological assays were observed. The extract fraction demonstrated effective inhibitory activity against Pseudomonas aeruginosa. As a result, this research suggests that extracts of the seaweed P. boergesenii contain potential bioactive compounds with significant antibiotic activity.

Effects of melatonin on cadmium accumulation and haematological parameters in cadmium intoxicated Prussian carp (Carassius gibelio B.)

The present study was performed to determine the effect of melatonin on cadmium accumulation and haematological parameters changes in females of Prussian carp (Carassius gibelio B.). The fish were exposed to a sublethal concentration of cadmium (0.4 and 4.0 mg/L) without or with melatonin implant (containing 18 mg melatonin hormone) for 1, 4, 7, 10 and 13 weeks. After the 7th week, Cd-exposed fish were divided into two groups. The first group of fish were subjected to depuration in clear water, while the second group remained exposed to the same concentrations of cadmium. After the 10th and 13th weeks of exposure the kidney, spleen, heart and blood were taken in order to determine the cadmium concentration and to analyse haematological parameters. The results of this study showed an increase in the concentration of cadmium in the tissues and blood in fish exposed to the highest dose (4.0 mg/L) of cadmium in water with a dependence on the exposure duration. Additionally, it was shown that melatonin administration reduced the cadmium concentration in the tissues and blood, and melatonin had a protective effect against cadmium accumulation. Moreover, the results showed a significant increase in blood parameters (RBC, Ht and Hb) in fish treated with the highest dose of cadmium. However, implantation of melatonin in cadmium-treated fish resulted in marked improvements in haematological parameters. Thus, melatonin can be a good implementation to alleviate, at least partially, the toxicity of cadmium.