Immunosuppressive Effects of Thallium Toxicity in Nile Tilapia Fingerlings: Elucidating the Rescue Role of Astragalus membranaceus Polysaccharides

This study evaluated the immunotoxic effects of thallium (Tl) in Nile tilapia fingerlings and the recovery role of dietary Astragalus membranaceus polysaccharides (ASs). An 8-week experiment was designed where 180 fishes were randomly and equally assigned in triplicates into the six groups: the control group (CNT) was reared in unpolluted water and fed a commercial diet, two groups were fed a well-balanced commercial diet plus 1.5 and 3.0 g AS/kg diet (AS0.15 and AS0.30), respectively, the fourth group was exposed to a sublethal dose of Tl (41.9 μg l−1) [equal to 1/10 of 96-h lethal concentration 50 (LC50)], and the last two groups were fed 0.15 and 0.3% AS, respectively, and concurrently exposed to Tl (41.9 μg l−1) (AS0.15+Tl and AS0.30+Tl). Fish hematobiochemical parameters, serum immunity [nitric oxide, total immunoglobulin M (IgM) levels, and lysozyme activity], transcription of hepatic interferon-g (IFN-g), interleukin-1b (IL-1b), and tumor necrosis factor-a (TNF-a), and resistance to Aeromonas hydrophila (A. hydrophila) were assessed. Hematobiochemical parameters and serum immune indices were significantly decreased in the fish group exposed to sublethal Tl concentration compared to the CNT group. Furthermore, Tl exposure significantly induced overexpression of IL-1b, TNF-a, and IFN-g genes (4.22-, 5.45-, and 4.57-fold higher, respectively) compared to CNT values. Tl exposure also increased the cumulative mortality (%) in Nile tilapia challenged with A. hydrophila. Remarkably, the groups fed AS0.15+Tl and AS0.30+Tl significantly ameliorated all the aforementioned parameters, but did not reach CNT values. Our findings suggest the possible immunomodulating roles of dietary AS in recovering the immunotoxic effects of Tl in Nile tilapia. We can conclude that dietary AS would be useful for maintaining the immunity of Nile tilapia fingerlings

Modulatory effect of thymol on the immune response and susceptibility to Aeromonas hydrophila infection in Nile tilapia fish exposed to zinc oxide nanoparticles

Zinc oxide nanoparticles (ZnO-NPs) have many exciting properties that make their use in a continuous increase in various biomedical, industrial, and agricultural applications. This is associated with accumulation in the aquatic ecosystems and fish exposure with consequent deleterious effects. To determine the potential of thymol to counteract the immunotoxic effects of ZnO-NPs, Oreochromis niloticus was exposed to ZnO-NPs (⅕ LC50 =1.14 mg/L, for 28 days) with or without feeding a thymol-incorporated diet (1 or 2 g/kg diet). Our data demonstrated a reduction of aquaria water quality, leukopenia, and lymphopenia with a decrease in serum total protein, albumin, and globulin levels in exposed fish. At the same time, the stress indices (cortisol and glucose) were elevated in response to ZnO-NPs exposure. The exposed fish also revealed a decline in serum immunoglobulins, nitric oxide, and the activities of lysozyme and myeloperoxidase, in addition to reduced resistance to the Aeromonas hydrophila challenge. The RT-PCR analysis showed downregulation of antioxidant (SOD) superoxide dismutase and (CAT) catalase gene expression in the liver tissue with overexpression of the immune-related genes (TNF-α and IL-1β). Importantly, we found that thymol markedly protected against ZnO-NPs-induced immunotoxicity in fish co-supplemented with thymol (1 or 2 g/kg diet) in a dose-dependent manner. Our data confirm the immunoprotective and antibacterial effects of thymol in ZnO-NPs exposed fish, supporting the potential utility of thymol as a possible immunostimulant agent

Dietary Supplementation of Nile Tilapia (Oreochromis niloticus) With Panax ginseng Essential Oil: Positive Impact on Animal Health and Productive Performance, and Mitigating Effects on Atrazine-Induced Toxicity

The present study assessed the impact of Panax ginseng essential oil (GEO) supplementation on physiological parameters related to productive performance and health status in Nile tilapia reared under standard conditions and exposed to a sub-lethal atrazine (ATZ) concentration. Fish were allocated into 6 groups: the control group was reared in clean water and fed with a commercial basal diet (CNT), two groups were fed with the basal diet supplemented with two different levels of GEO (GEO1 and GEO2, respectively), one group was intoxicated with 1/5 of ATZ 96-h lethal concentration 50 (1.39 mg/L) (ATZ group), and the remaining two groups were fed with the GEO-supplemented diets and concurrently exposed to 1.39 mg ATZ/L (GEO1+ATZ and GEO2+ATZ, respectively). The experiment lasted for 60 days. GEO supplementation exerted a significantly positive influence on fish growth, feed utilization, and hepatic antioxidant defense systems at both levels of supplementation. ATZ exposure significantly reduced fish survival rates and impaired fish growth and feed utilization, with the lowest final weights, weight gain, total feed intake, and the highest feed conversion ratio being recorded in the ATZ-intoxicated group. ATZ exposure caused significant changes in intestinal digestive enzyme activity (decreased lipase activity), hematological indices (decreased hemoglobin, packed cell volume, erythrocytes, and leukocytes), blood biochemical variables (decreased total proteins, albumin, globulins, and immunoglobulin M; increased total cholesterol, triglycerides, and cortisol), and hepatic oxidative/antioxidant indices (decreased glutathione level, superoxide dismutase and catalase enzyme activity and mRNA expression levels, and increased malondialdehyde content). Moreover, in the hepatic tissue of ATZ-intoxicated Nile tilapia, histopathological alterations and upregulated mRNA expression levels of stress- and apoptosis-related genes (Hsp70, caspase 3, and p53) were observed. GEO supplementation in ATZ-treated groups significantly attenuated the aforementioned negative effects, though some parameters did not reach the CNT values. These findings provide further and partly new evidence that sub-lethal ATZ toxicity induces reduced survivability, growth retardation, impaired digestive function, anemia, immunosuppression, hepatic oxidative stress damage, and overall increased stress level in Nile tilapia, and suggest that GEO supplementation may be useful for mitigating this toxicity and provide more general support to the productive performance and health status of this fish species

Zinc Oxide Nanoparticles (ZnO-NPs) Suppress Fertility by Activating Autophagy, Apoptosis, and Oxidative Stress in the Developing Oocytes of Female Zebrafish

In vertebrates, the core mechanisms that control gametogenesis are largely multiple, complex, successive, and orchestrated by intrinsic and extrinsic factors. However, age, health status, and hormonal activity are important factors for good fertility; other intangible intracellular molecular mechanisms that manage oocyte development are still unclear. The present study was designed to elucidate the ultrastructure changes in the ovary in response to its exposure to zinc oxide nanoparticles (ZnO-NPs) and to explore the role of autophagy and apoptosis during egg maturation and ovulation on the fertility of female zebrafish. In our study, ZnO-NPs could induce cytotoxicity in the maturing oocyte by activating autophagy and apoptosis in a caspase-dependent manner and could induce oxidative stress by generating reactive oxygen species (ROS) that elevated the mutated ovarian tP53 protein. Simultaneously, necroptosis developed, mimicking the features of apoptosis and necrosis. Collectively, ZnO-NPs created a suitable necrotic environment that led to follicular developmental retardation that altered oocyte ovulation and reduced fecundity of female zebrafish

In ovo protective effects of chicoric and rosmarinic acids against Thiacloprid-induced cytotoxicity, oxidative stress, and growth retardation on newly hatched chicks

Thiacloprid (TH) is a neonicotinoid insecticide employed in agriculture to protect fruits and vegetables against different insects. It showed different deleterious effects on the general health of non-target organisms including birds and animals, however, its developmental toxicity has yet to be fully elucidated. Chicoric (CA) and rosmarinic (RA) acids are polyphenolic compounds with a wide range of beneficial biological activities. In this study, the possible protective effects of CA and RA were investigated in chick embryos exposed in ovo to TH (1mg/egg) with or without CA (100 mg/egg) or RA (100 mg/egg) co-exposure. TH reduced the hatchling body weight, body weight/egg weight, and relative weight of bursa of Fabricius in the one-day-old hatchlings. Examination of the 7-day-old chicks revealed a decline in feed intake, daily weight gain, feed conversion ratio (FCR), and plasma levels of T3, T4, and growth hormone. Serum ALT, AST activities, and total cholesterol levels showed significant elevations. Hepatic MDA was increased with a reduction in SOD activity and GSH level and downregulation of the liver SOD and GST gene expression pattern. Serum IgG and IgM levels were reduced, and various histopathological alterations were noticed in the liver. Co-administration of CA or RA with TH mitigated the toxic effects on hatchlings. When both CA and RA are combined, they present a synergistic protective effect. CA and RA can be used as protective agents against TH toxicity as they improve growth performance and have hepatoprotective and immunostimulant effects in newly hatched chicks

Physiological and Neurobehavioral Disturbances Induced by Al2O3 Nanoparticle Intoxication in Nile Tilapia Fish: Benefits of Dietary Chamomile Essential Oil

Despite the usage of nanoparticles (NPs) is rapidly increasing, several experts have noted the risk of their release into ecosystems and their potential negative impacts on biological systems. However, the available studies on the neurobehavioral impacts of aluminum oxide nanoparticles (Al2O3NPs) on aquatic organisms are little. Hence, this study targeted to ascertain the harmful effects of Al2O3NPs on behavioral characteristics and genotoxic and oxidative damages in Nile tilapia fish. In addition, the beneficial role of chamomile essential oil (CEO) supplementation in reducing these effects was also investigated. In the current study, fish were distributed into 4 equal groups (n = 60 fish per group). The control group was fed a plain diet only, the CEO group received a basic diet complemented with CEO at a level of 2 mg/kg diet, the ALNP group received a basic diet and was exposed to an approximate concentration of 1/10th LC50 of ALNPs nearly 5.08 mg/L, and the combination group (ALNPs/ CEO group) received a basal diet coadministered with ALNPs and CEO at the aforementioned percentages. The findings revealed that O. niloticus exhibit neurobehavioral changes along with changes in the level of GABA, monoamines in the brain tissue, and serum amino acid neurotransmitters, besides a reduction of AChE and Na+/K+-ATPase activities. In addition to brain tissue oxidative damage with upregulation of proinflammatory and stress genes, such as HSP70 and caspase-3, supplementation of CEO significantly reduced the negative impacts of ALNPs. These results showed that CEO has neuroprotective, antioxidant, genoprotective, anti-inflammatory, and antiapoptotic properties in fish that have been exposed to ALNPs. Therefore, we advise its usage as a valuable addition to fish diet

The Toxicological Aspects of the Heat-Borne Toxicant 5-Hydroxymethylfurfural in Animals: A Review

The incidence of adverse reactions in food is very low, however, some food products contain toxins formed naturally due to their handling, processing and storage conditions. 5-(Hydroxymethyl)-2-furfural (HMF) can be formed by hydrogenation of sugar substances in some of manufactured foodstuffs and honey under elevated temperatures and reduced pH conditions following Maillard reactions. In previous studies, it was found that HMF was responsible for harmful (mutagenic, genotoxic, cytotoxic and enzyme inhibitory) effects on human health. HMF occurs in a wide variety of food products like dried fruit, juice, caramel products, coffee, bakery, malt and vinegar. The formation of HMF is not only an indicator of food storage conditions and quality, but HMF could also be used as an indicator of the potential occurrence of contamination during heat-processing of some food products such as coffee, milk, honey and processed fruits. This review focuses on HMF formation and summarizes the adverse effects of HMF on human health

Thiacloprid Induced Developmental Neurotoxicity via ROS-Oxidative Injury and Inflammation in Chicken Embryo: The Possible Attenuating Role of Chicoric and Rosmarinic Acids

Insecticides are widely employed in agriculture to control pests and as major factors for enhancing crop productivity. Thiacloprid (TH) is one of the most-used insecticides worldwide. In this study, the negative impact of TH on the brain tissue of developing chicken embryo models and the modulatory effect of chicoric (CA) and rosmarinic (RA) acids were investigated. The eggs were injected in ovo with different doses of TH (0.1, 1, 10, and 100 μg/egg). TH significantly increased the oxidative damage in the brain of exposed embryos in a dose-dependent manner (p < 0.05). TH significantly elevated the oxidative stress markers; protein carbonyl, malondialdehyde content, and DNA damage (p < 0.05). Myeloperoxidase activity and nitric oxide significantly increased with overexpression of the pro-inflammatory cytokines (interferon gamma, tumor necrosis factor alpha, and interleukin-1 beta) and stress-related and apoptotic genes (NF-KB, Caspase-3) in the brain tissue on both biochemical and molecular levels (p < 0.05), while downregulating the expression of antiapoptotic Bcl-2. Co-treatment of CA and RA with TH markedly decreased the insecticide-induced toxicity with a prominent synergistic effect (p < 0.05). In conclusion, TH is suggested to be a possible neurotoxic to embryos of vertebrates including human. The study also revealed the antioxidant, anti-inflammatory, genoprotective, and antiapoptotic property of CA and RA against TH toxicity

Alleviative effect of some phytochemicals on cyadox-induced oxidative damage in rabbit erythrocytes

This study was carried out to evaluate the effects of different concentrations of cyadox (CYA), cinnamaldehyde (CIN) and resveratrol (RES) on rabbit isolated erythrocytes in two experiments. Experiment 1 evaluated the effects of different concentrations (2.5, 5, 10, 20, 40, 60, 80 and 100) μg/ml of CYA and μM of both CIN and RES separately on isolated erythrocytes in order to make the concentration response curve. Results indicated that CYA caused a significant depletion of reduced glutathione (GSH) content compared to control at 40 μg/ml and the depletion increased by increasing the concentration. On the other hand, both RES and CIN showed a highly significant elevation of GSH content at 40 μM being more effective by increasing concentrations. Experiment 2 investigated the potential benefits of using CIN and RES separately or in combination on CYA induced alterations in isolated rabbit erythrocytes (the used concentrations were based on the results of experiment 1). Results revealed that exposure to CYA caused a significant decrease in superoxide dismutase (SOD) and catalase (CAT) activities and reduced glutathione (GSH) and total protein (TP) contents, CYA also elevated extracellular hemoglobin (Hb) and adenosine triphosphate (ATP), increased the malonaldehyde (MDA) and protein carbonyl (PrC) contents with increasing caspase3 and caspase8 activities suggesting CYA pro-oxidant effect. Both CIN and RES were able to inverse these hazardous effects of CYA. However, CIN was more effective than RES, and their combination showed a positive synergistic effect in protecting cells against oxidative injury caused by CYA