The Probiotic Lactobacillus sakei Subsp. Sakei and Hawthorn Extract Supplements Improved Growth Performance, Digestive Enzymes, Immunity, and Resistance to the Pesticide Acetamiprid in Common Carp (Cyprinus carpio).

This study evaluated the impacts of the probiotic, Lactobacillus sakei (L. sakei), and the extract of hawthorn, Crataegus elbursensis, on growth and immunity of the common carp exposed to acetamiprid. Fish (mean ± SE: 11.48 ± 0.1 g) feeding was done with formulated diets (T 1 (control): no supplementation, T 2: 1 × 106 CFU/g LS (Lactobacillus sakei), T3: 1 × 108 CFU/g LS, T 4: 0.5% hawthorn extract (HWE), and T 5: 1% HWE) for 60 days and then exposed to acetamiprid for 14 days. The growth performance improved in the fish fed LS at dietary level of 1 × 108 CFU/g, even after exposure to acetamiprid (P < 0.05). Intestinal Lactobacillus sakei (CFU/g) load increased (P < 0.05), following supplementation with the probiotic-enriched diet. The LS-treated fish had increases in the activity of digestive enzymes (P < 0.05). Both LS and HWE stimulated antioxidant enzymes and immune system components in serum and mucus (alkaline phosphatase (ALP), protease, total Ig, and lysozyme) (P < 0.05). However, the changes were different depending on the kind of the supplement. The malondialdehyde (MDA) levels decreased in HWE-treated fish after acetamiprid exposure (P < 0.05). Both LS and HWE reduced the liver metabolic enzymes (LDH, ALP, AST, ALT, and LDH) in serum both before and after exposure to the pesticide (P < 0.05). However, each enzyme exhibited a different change trend depending on the type of the supplement. HWE showed a stress-ameliorating effect, as glucose and cortisol levels declined in the HWE-treated fish (P < 0.05). This study indicated the immunomodulatory impacts of LS (1 × 108 CFU/g) and HWE (at dietary levels of 0.5-1%). The probiotic showed more performance compared to HWE. However, the HWE mitigated oxidative stress more efficiently than the probiotic.

Microplastic and oil pollutant agglomerates synergistically intensify toxicity in the marine fish, Asian seabass, Lates calcalifer.

Asian seabass, Lates calcarifer frys were exposed to polystyrene (MP: 0.5 mg/l), oil (0.83 ml/l) and agglomerates (MP + oil + Corexit) as eight treatments in three replicates, and fresh synthetic marine water (control) for 15 days. The synergistic effect was confirmed (P ˂ 0.05) by bio-indicators including RBC count, total plasma protein, aspartate aminotransferase (AST), catalase (CAT), glutathione S-transferase (GST), basophils, thrombocyte and eosinophils percentages. Most of the significant and synergistic effects were observed in the highest doses (5 mg/l MP and 5 mg/l MP-oil-dispersant). Exposure to MP and a combination of MP+ oil caused tissue lesions in gill, liver and intestine. Our results suggest there are no critical health issues for Asian seabass in natural environments. However, the bioaccumulation of MPs, oil, and their agglomerates in consumers' bodies may remain a concern.

Modulatory role of dietary curcumin and resveratrol on growth performance, serum immunity responses, mucus enzymes activity, antioxidant capacity and serum and mucus biochemicals in the common carp, Cyprinus carpio exposed to abamectin.

In this study, we investigate the potentials of dietary curcumin and resveratrol on blood biochemistry, immune responses and resistance to the toxicity of the pesticide, abamectin. 540 common carps (30.78 ± 0.17 g) were randomly distributed into 18 tanks (30 fish per tank), as six experimental groups (T1: non-supplemented and on-exposed fish, T2: 300 mg/kg curcumin, T3: 300 mg/kg resveratrol, T4: 12.5% LC50 of abamectin, T5: 300 mg/kg curcumin +12.5% LC50 of abamectin, T6: 300 mg/kg resveratrol + 12.5% LC50 of abamectin). Use of 300 mg/kg resveratrol in the diet of non-abamectin exposed fish improved the growth performance (P < 0.05), while such effects were not observed for curcumin (P > 0.05). There were no differences in the final weight (FW), feed conversion ratio (FCR) and weight gain (WG) between control and fish of the treatments, resveratrol + abamectin and curcumin + abamectin (P < 0.05). The immune components in blood [lysozyme, complement activity, Total immunoglobulin (total Ig), protease, myeloperoxidase (MPO), nitro-blue-tetrazolium (NBT), peroxidase, albumin] and mucus [acid phosphatase (ACP), alkaline phosphatase (ALP), esterase, antiprotease)] and antioxidant enzymes [(superoxide dismutase (SOD), glutathione peroxidase (GPx)] exhibited various change patterns compared to the control group, however, these components were almost all higher in fish supplemented with curcumin and resveratrol in an abamectin-free medium than in control and other groups (P < 0.05). In most cases, the levels of immune and antioxidant components in the control did not show significant difference with the treatments, resveratrol + abamectin and curcumin + abamectin (P > 0.05). Abamectin induced oxidative stress in fish, as the malondialdehyde (MDA) levels significantly increased in the exposed fish compared to non-exposed groups (P < 0.05). It appears that neither curcumin nor resveratrol were as effective in preventing oxidative stress, because MDA levels were higher in exposed fish (abamectin, curcumin + abamectin, resveratrol + abamectin) than in control and non-exposed individuals (P < 0.05). Curcumin and resveratrol also showed protective effects on liver, since the levels of liver metabolic enzymes [aspartate transaminase (AST), ALP, lactate dehydrogenase (LDH)] were lower in the supplemented fish in a abamectin-free medium than in control (P < 0.05). Curcumin and resveratrol also mitigated the stress responses in the exposed fish, as cortisol and glucose levels showed significant decreases in the supplemented fish (P < 0.05). In conclusion, this study revealed that abamectin can depress the growth and immunity in the common carp. Although, both resveratrol and curcumin were mitigated the toxic effects of abamectin, it seems that resveratrol be more effective than curcumin.

Size-dependent effects of microplastic on uptake, immune system, related gene expression and histopathology of goldfish (Carassius auratus).

Todays, with the industrialization of human societies, pollution of aquatic ecosystems with plastics derivatives are a serious concern, affecting the life of their organisms. The present study was conducted to investigate the size effects of micro-plastic, polystyrene on some physiological lesions of the goldfish, Carassius auratus. Fish were exposed to two sizes (0.25 and 8 µm) polystyrene at different environmentally relevant concentrations. The exposure trial was done in two steps. First, fish exposed to a stable concentration of 300 mg/L polystyrene for 168 h. Gill, intestine, and liver tissues were sampled every 24 h to investigate the accumulation of polystyrene. Then, fish were exposed in three replicates to 0 (control), 0.05, 0.5, and 5 mg/L polystyrene in two sizes of 0.25 and 8 µm for 28 days. After the exposure period, gill, liver, and intestine tissues were sampled for histological study, also, serum samples were collected for biochemical assays. Fluorescent microscope observations confirmed the accumulation of polystyrene in tissue samples with time. In addition, histological lesions were found in the liver, intestine, and gill of the exposed fish. The severity of lesions showed a size and dose-dependent pattern. Polystyrene induced the antioxidant system of exposed fish through elevating the levels of SOD and CAT activity and significant difference in expression of antioxidant related genes (CAT, SOD and HSP70). In conclusion, the results of the present study confirmed the toxic effects of microplastic, polystyrene on goldfish.

Effects of polystyrene microparticles on inflammation, antioxidant enzyme activities, and related gene expression in Nile tilapia (Oreochromis niloticus).

Due to the importance of Nile tilapia in the aquaculture sector, the present study aimed to evaluate the adverse impacts of the polystyrene microparticles (PS-MPs) on inflammation, immune, and antioxidative responses. For this reason, fish were exposed to waterborne PS-MPs at two sizes (9 µm and 0.35 µm) beside the control group for 28 days. Regardless of particle size, the final weight, weight gain, specific growth rate, and feed conversion ratio of Nile tilapia were not influenced by the PS-MPs exposure (P > 0.05). Superoxide dismutase (SOD), glutathione peroxidase (GPX), and malondialdehyde (MDA) levels were significantly increased in the group exposed to 9 µm and followed by those exposed to 0.35 µm while the lowest SOD, GPX, and MDA were in the control group. The expression of catalase (CAT) and lysozyme genes were upregulated in the group of fish exposed to 9 µm (P < 0.05). The expression of the interferon-gamma (IFN-γ) gene was upregulated in fish exposed to 9 µm and 0.35 µm when compared with the control (P < 0.05). The expression of interleukin 8 (IL8), interleukin (IL-1ß), and tumor necrosis factor (TNF-α) genes was upregulated in the group of fish exposed to 9 µm (P < 0.05). The hepatic mRNA levels of cytochrome P450 (CYP450) gene were significantly upregulated in the group of fish exposed to 9 µm when compared with the control (P < 0.05) without significant differences with those exposed to 0.35 µm (P > 0.05). The obtained results refer to the adverse effects of PS-MPs on the antioxidative, inflammatory, and detoxification-related genes of Nile tilapia.

Microplastics distribution, abundance and composition in sediment, fishes and benthic organisms of the Gorgan Bay, Caspian sea.

Microplastic is releaseing to the aquatic environment worldwide, so they considered as a global issue and appeare to be widespread in all level of aquatic ecosystems and reveal serious threats to biota. Since they are often ingested by living organisms, the major concern is their transferring from lower trophic level to higher trophic level through the food chain. Due to the importance of Gorgan Bay as one of the ecologically important areas of the Caspian Sea and the need for fundamental information on the pollution status of this region, a study conducted for evaluation of microplastic pollution in sediments, fish and benthose, from 3 areas (north, central, south) through sampling from 21 stations. The range of microplastics (MPs) abundance in sediments was 80 ± 25 to 740 ± 105 n/kg. Fibers, Black MPs, and size of 1-2 mm (42.4%) were prevalence observed in sediment and living organisms. According to the FTIR results, among studied organisms, the most microplastic levels were found in the soft tissues of fish Neogobius melanostomus (39 MP/g) and mussel Cerastoderma lamarcki (19.8 MP/g) dry weight. The results of this study present the comprehensive information on MPs distribution and charecteristics in sediments, fish and mussel of Gorgan Bay which could help to run better management over this sensitive ecosystem and would be a start point for further research on MPs effect on organisms of the Caspian sea.