The omnipresence of microplastics and nanoparticles has led to their entry into the fresh and marine aquatic systems and affected the biota. The present study aims to evaluate the impact of the interaction of polyethylene microplastic (PE-MPs) and zinc oxide nanoparticles (ZnO-NPs) in mosquito fish, Gambusia holbrooki. For this, fish were exposed to 100 µg L−1 PE-MPs (group 2), 200 µg L−1 PE-MPs (group 3), 50 µg L−1 ZnO-NPs (group 4), 50 µg L−1 ZnO-NPs combined with 100 µg L−1 PE-MPs (group 5), and 200 µg L−1 PE-MPs (group 6) and control (group 1) for 14 days. The assessment was made through accumulation studies (MPs and Zn) and antioxidant assay. Significant elevation in the activity of catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase levels was observed in ZnO-NPs alone and in combination with PE-MPs (100 and 200 µg L−1) groups only. High malondialdehyde levels were observed in all the exposed groups. Concordantly total antioxidant (TAN) levels displayed a significant reduction in all treated groups compared to control. Accumulation study on microplastic suggested liver-targeted accumulation of PE-MPs, while for ZnO-NPs, observed PE-MPs assisted accumulation. The study affirms the induction of oxidative stress and ZnO-NPs-induced toxicity facilitated by PE-MPs in fish.
Synthetic chemicals, such as fertilizers and pesticides, are abundantly used in agriculture to enhance soil fertility and prevent the occurrence of diseases, respectively. Many studies have reported a negative influence of these chemicals on the soil environment. Natural sources from earthworms and their products, as a result of vermicomposting, may be considered better alternatives. The aim of this review was to reveal the source of antifungal efficiency of vermicompost and its derivatives, such as vermiwash, coelomic fluid, skin secretion of earthworms, and metabolites from decomposer bacteria in vermicompost, in order to highlight their application in agriculture. The synergistic activity of bioactive compounds present in coelomic fluid, mucus, skin secretion, and metabolites from associated bacteria (decomposer) assisted crop plants for effective action against various soil pathogenic fungi, such as Rhizoctoniasolani, Alternaria solani, Aspergillus niger, A.flavus, Fusariumoxysporum, and F. graminearum. Thus, these bioactive metabolites can be recommended to suppress plant fungal diseases. Vermicompost and its derivatives should be considered for use in agricultural fields to control harmful soil fungi and increase crop productivity.
Malachite green (MG) dye, besides coloring is used as an effective aquaculture therapeutic. The present study assesses the mitigating ability of Emblica officinalis (EO) fruit extract against the dye induced chronic (60 days) cyto-toxicity in Cyprinus carpio. For this, four experimental groups were maintained: group I—control, group II—MG, group III—EO (positive control), group IV—MG + EO. The study was made at three tiers: detailing structural anomalies using a light microscope and transmission electron microscope (TEM), biochemical estimation of antioxidant enzymes, and lipid peroxidation and molecular analysis of expression patterns of HSP70, and CYP1A genes. MG intoxication resulted in necrosis, cytoplasmic vacuolation, glycogen depletion, abundant macrophages, loss of cell integrity and prominent nuclear alterations. Significant (p < 0.05) inhibition in the activities of catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST) and reduced glutathione (GSH), along with an elevation in malondialdehyde (MDA) levels, occurred after 60 days of MG exposure. CYP1A and HSP70 genes presented a significant change in their expression in MG treated fish. Whereas oral supplementation with EO significantly restored the histo-architecture, normalized the altered enzymatic activity, reduced the oxidative stress level and regulated the expression of HSP70 and CYP1A genes. Thus, it can be concluded that EO acted as an effective ameliorant against malachite green induced cyto-toxicity in Cyprinus carpio.
11 November 2021 in Journal of Experimental Zoology Part A: Ecological and Integrative Physiology