Oxidative damage to lipids and proteins induced by aflatoxin B(1) in fish (Labeo rohita)-protective role of Amrita Bindu

Dietary Lactobacillus acidophilus ATCC 4356 Relieves the Impacts of Aflatoxin B1 Toxicity on the Growth Performance, Hepatorenal Functions, and Antioxidative Capacity of Thinlip Grey Mullet (Liza ramada) (Risso 1826)

Dietary Lactobacillus acidophilus ATCC 4356 was used to relieve the impacts of aflatoxin B₁ toxicity on the performances of Liza ramada. The control diet was without any additives, while the second and third diets were supplemented with aflatoxin B₁ at 0.5 and 1 mg/kg. The fourth diet was supplemented with Lb. acidophilus ATCC 4356 at 1 × 10⁶ CFU/mL per kg diet, while the fifth with aflatoxin B₁ at 1 mg/kg and Lb. acidophilus ATCC 4356 at 1 × 10⁶ CFU/mL per kg diet. The growth performance markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356, while aflatoxin B₁ at 0.5 and 1 mg/kg groups showed a severe reduction. The red blood cells, hemoglobulin, hematocrit, and white blood cells were markedly increased in L. ramada fed Lb. acidophilus ATCC 4356 while decreased (p < 0.05) in fish fed aflatoxin B₁ at 0.5 and 1 mg/kg. The blood total protein and albumin were markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356 while reduced in aflatoxin B₁ at 0.5 and 1 mg/kg groups. The levels of total cholesterol and triglycerides were meaningfully increased in fish of the Lb. acidophilus ATCC 4356 and aflatoxin B₁ at 1 mg/kg groups while decreased in aflatoxin B₁ at 0.5 and 1 mg/kg groups. Alanine aminotransferase, aspartate aminotransferase, creatinine, and urea levels were markedly decreased (p < 0.05) in fish-fed Lb. acidophilus ATCC 4356 while increased in aflatoxin B₁ at 0.5 and 1 mg/kg groups. The highest levels of blood glucose and cortisol were seen in fish contaminated with aflatoxin B₁ at 1 mg/kg, while the lowest levels were observed in the fish fed Lb. acidophilus ATCC 4356 group (p < 0.05). The catalase and superoxide dismutase were markedly enhanced in the Lb. acidophilus ATCC 4356 group and severely declined in aflatoxin B₁ at 0.5 and 1 mg/kg groups (p < 0.05). The malondialdehyde level was markedly reduced in fish fed Lb. acidophilus ATCC 4356 with or without aflatoxin B₁ at 1 mg/kg diets while increased in fish contaminated with aflatoxin B₁ at 0.5 and 1 mg/kg (p < 0.05). The control group had lower malondialdehyde levels than the aflatoxin B₁ at 1 mg/kg group and higher than the Lb. acidophilus ATCC 4356 with or without aflatoxin B₁ toxicity (p < 0.05). Histopathological examination revealed impaired intestines and livers in fish contaminated with aflatoxin B₁ while Lb. acidophilus ATCC 4356 relieves the inflammation and protected the intestines and livers. In conclusion, dietary Lb. acidophilus ATCC 4356 is recommended to relieve the impacts of aflatoxicosis-induced hepatorenal failure and oxidative stress in L. ramada.

Fabrication, physico-chemical characterization, and bioactivity evaluation of chitosan-linalool composite nano-matrix as innovative controlled release delivery system for food preservation

The aim of the present study was to encapsulate linalool into chitosan nanocomposite (Nm-linalool) for developing novel controlled release delivery system in order to protect stored rice against fungal infestation, aflatoxin B₁ (AFB₁) contamination, and lipid peroxidation. The chitosan-linalool nanocomposite showed spherical shapes, smooth surface with monomodal distribution as revealed by SEM and AFM investigation. FTIR and XRD represented peak shifting and changes in degree of crystallinity after incorporation of linalool into chitosan nanocomposite. Nanoencapsulation of linalool showed higher zeta potential and lowered polydispersity index. TGA analysis reflected the stability of Nm-linalool with reduced weight loss at varying temperatures. Biphasic pattern, with initial rapid release followed by sustained release illustrated controlled delivery of linalool from chitosan nanocomposite, a prerequisite for shelf-life enhancement of stored food products. Chitosan nanocomposite incorporating linalool displayed prominent antifungal and antiaflatoxigenic activity during in vitro as well as in situ investigation in rice with improved antioxidant potentiality. Further, Nm-linalool displayed considerable reduction of lipid peroxidation in rice without exerting any adverse impact on organoleptic attributes. In conclusion, the investigation strengthens the application of chitosan-linalool nanocomposite as an innovative controlled nano-delivery system for its practical application as novel environmentally friendly eco-smart preservative in food and agricultural industries.

Sublethal diclofenac induced oxidative stress, neurotoxicity, molecular responses and alters energy metabolism proteins in Nile tilapia, Oreochromis niloticus

Reports have shown that residues of pharmaceuticals and their metabolites can pose toxicological threats to organisms living in aquatic ecosystem. Nile tilapia, Oreochromis niloticus, was exposed at 0.17, 0.34, and 0.68 mg L^-1 of diclofenac up to 60 days in a renewal static bioassay system. Antioxidant enzymes reactions, molecular responses, activities of energy metabolism proteins, and the neurotoxic potentials of the drug in the brain and fish muscle were evaluated. Antioxidant enzyme activities such as superoxide dismutase, glutathione-S-transferase, and also fructose 1, 6 bisphosphatase and glucose-6-phosphate dehydrogenase as well as the levels of lipid peroxidation and protein carbonyl were elevated, while glutathione peroxidase, total reduced glutathione, and acetylcholinesterase in the brain and muscles of the treated groups were significantly inhibited in a dose-dependent association. Expression of superoxide dismutase (sod), catalase (cat), and heat shock proteins (hsp 70) genes in brain and muscle tissues was up-regulated. Continuous treatment with sublethal diclofenac for a long time can induce oxidative imbalance, cause neurotoxicity, and alter the expression of genes related to stress in Nile tilapia, suggesting the use of these biomarkers in monitoring the adverse effects the pharmaceuticals could cause to organisms in aquatic ecosystem for possible mitigation.

Cytotoxicity assessment of Aflatoxin B1 after high voltage atmospheric cold plasma treatment

Aflatoxin B1 (AFB1) is a secondary metabolite produced by Aspergillus flavus and A. parasiticus, and is a known carcinogen in humans and animals. High voltage atmospheric cold plasma (HVACP) technology has already shown promise to decontaminate AFB1 in food and feed. This study aimed to investigate the cytotoxicity of AFB1 after HVACP treatment. AFB1 (100 μM) was treated at 85 kV with HVACP for 0, 2, 5, 10, and 20 min. HepG2 cells were exposed to HVACP-treated AFB1 for 72 h and assessed for cell viability, caspase-3 activity, DNA fragmentation, and protein carbonyls for each treatment time. Cell viability, caspase-3 activity, DNA fragmentation levels, and protein carbonyls contents of HepG2 cells exposed to HVACP-treated AFB1 after 20 min was not significantly different compared to non-exposed HepG2 cells (P > 0.05). However, their contents were significantly higher in non-exposed cells compared to the other HVACP treatment times (P < 0.01). Twenty minutes of HVACP treatment for AFB1 significantly reduced AFB1 cytotoxicity and oxidative damage and showed potential as a safe aflatoxin decontamination technology.

The Assessment of Diet Contaminated with Aflatoxin B1 in Juvenile Turbot (Scophthalmus maximus) and the Evaluation of the Efficacy of Mitigation of a Yeast Cell Wall Extract

This study aimed to investigate the effects of dietary AFB₁ on growth performance, health, intestinal microbiota communities and AFB₁ tissue residues of turbot and evaluate the mitigation efficacy of yeast cell wall extract, Mycosorb^® (YCWE) toward AFB₁ contaminated dietary treatments. Nine experimental diets were formulated: Diet 1 (control): AFB₁ free; Diets 2-5 or Diets 6-9: 20 μg AFB₁/kg diet or 500 μg AFB₁/kg diet + 0%, 0.1%, 0.2%, or 0.4% YCWE, respectively). The results showed that Diet 6 significantly decreased the concentrations of TP, GLB, C3, C4, T-CHO, TG but increased the activities of AST, ALT in serum, decreased the expressions of CAT, SOD, GPx, CYP1A but increased the expressions of CYP3A, GST-ζ₁, p53 in liver. Diet 6 increased the AFB₁ residues in serum and muscle, altered the intestinal microbiota composition, decreased the bacterial community diversity and the abundance of some potential probiotics. However, Diet 8 and Diet 9 restored the immune response, relieved adverse effects in liver, lowered the AFB₁ residues in turbot tissues, promoted intestinal microbiota diversity and lowered the abundance of potentially pathogens. In conclusion, YCWE supplementation decreased the health effects of AFB₁ on turbot, restoring biomarkers closer to the mycotoxin-free control diet.

Dietary vegetable choline improves hepatic health of Nile tilapia (Oreochromis niloticus) fed aflatoxin-contaminated diet

Aflatoxin B_{1 (}AFB₁) is one of the most important mycotoxins due to its hepatotoxic and carcinogenic effects on animals. The effect of dietary supplementation with vegetable choline (VC) at 400, 800, and 1200 mg/kg against the deleterious effects of AFB₁ (2 ppm/kg diet) in the liver of Nile tilapia (Oreochromis niloticus) was studied. The experimental period was 81 days, and the diet with VC was offered to the fish for 60 days prior to challenge with AFB₁. Diets with AFB₁ were tested in three replications and animals were analyzed at days 14 and 21 of dietary intake. The addition of VC to tilapia diet increased body weight (days 30 and 60 pre-challenge and day 21 post-challenge). The group fed aflatoxin-contaminated diet presented significantly reduced antioxidant enzymes and increased reactive oxygen species (ROS) levels, thiobarbituric acid reactive species (TBARS) levels, and protein carbonyl (PC) content in the liver. Dietary supplementation with VC at 800 and 1200 mg/kg demonstrated a significant protective effect, avoiding the increase of ROS, TBARS, and PC levels in the liver of tilapia from the aflatoxin contaminated groups. Thus, dietary VC supplementation may be used in tilapia to increase antioxidant status and reduce the negative effects caused by AFB₁ toxicity. Based on the findings, it is recommended to use VC as a food supplement for Nile tilapia in order to avoid AFB₁ toxication. In addition, decreased aflatoxin toxicity can be attributed to the VC antioxidant property.

Melaleuca alternifolia essential oil abrogates hepatic oxidative damage in silver catfish (Rhamdia quelen) fed with an aflatoxin-contaminated diet

Mycotoxins are secondary metabolites produced by varieties of fungi that contaminate food and feed resources and are capable of inducing a wide range of toxicity. This problem is extensively aggravated due to the increasing replacement of fish meal by plant-derived proteins. Among the mycotoxins, aflatoxins have received a great deal of attention owing to their great prevalence in plant feedstuffs and to the detrimental effects on animals. The objective of this study was to evaluate whether dietary supplementation with tea tree (Melaleuca alternifolia) oil (TTO) would avoid or minimize the negative impacts on silver catfish (Rhamdia quelen) fed with aflatoxins-contaminated diets. Four treatments were tested: control (fish fed with a control diet); AFB (fish fed with a mycotoxin-contaminated diet - 1893 μg kg^-1 of AFB₁ and 52.2 μg kg^-1 AFB₂); TTO (fish fed with a control diet + 1 mL kg^-1 of TTO), and TTO + AFB (fish fed with a mycotoxin contaminated diet - 2324 μg kg^-1 of AFB₁ and 43.5 μg kg^-1 AFB₂ + 1 mL kg^-1 of TTO). Diets were tested in three replications and analyzed at days 5 and 10 of dietary intake. Significantly reduced antioxidant enzymes (SOD, GPx, and GST) and increased lipid peroxidation (LOOH) and protein carbonyl (PC) content in plasma and liver, with 16.6% mortality occurrence, were observed in the group fed aflatoxin-contaminated diet. Furthermore, aflatoxins also significantly increased plasmatic and hepatic ROS levels and decreased hepatic antioxidant capacity against peroxyl radical (ACAP) levels. Plasma cortisol levels were not altered by aflatoxicosis, but the intoxication induced hepatose. Notwithstanding, addition of TTO to the groups receiving aflatoxins showed a protective effect, avoiding the increase of ROS, LOOH, and PC levels in plasma and liver. Moreover, TTO treatment ameliorated the aflatoxin-associated liver damage. Thus, TTO supplementation at concentration of 1 mL kg^-1 in feed may be used in fish to increase antioxidant status and reduce the negative effects caused by aflatoxins toxicity.

Oxidative stress mediated the inhibition of cerebral creatine kinase activity in silver catfish fed with aflatoxin B1-contaminated diet

Aflatoxin B₁ (AFB₁) is an environmental toxicant and neurotoxic compound that induces the production of free radicals, causing oxidative stress. Creatine kinase (CK) is a central controller of energy metabolism in tissues with a large and fluctuating energy demand, and it is highly susceptible to inactivation by free radicals and oxidative damage. Thus, the aim of this study was to evaluate whether a diet for freshwater silver catfish (Rhamdia quelen) containing AFB₁ inhibits cerebral CK activity, as well as the involvement of the oxidative stress on this inhibition. Brain CK activity was lower on days 14 and 21 post-feeding in animals that received AFB₁-contaminated diet compared to the control group (basal diet), similarly to the brain sodium-potassium pump (Na⁺, K⁺-ATPase) activity. On the other hand, lipid peroxidation and protein carbonylation levels were higher on days 14 and 21 post-feeding in animals fed with AFB₁-contaminated feed compared to the control group, while the antioxidant capacity against peroxyl radicals and thiol content was lower. Based on these evidences, the data demonstrated that diet containing AFB₁ severely affects CK activity, an essential enzyme that plays an important role in brain energy homeostasis. Also, the impairment of energetic homeostasis linked with the use and generation of ATP via inhibition of CK activity elicited an inhibition of enzymes ATP-dependent, such as Na⁺, K⁺-ATPase. Moreover, the inhibition of brain CK activity appears to be mediated by the oxidation of lipids, proteins, and thiol group, as well as by a reduction in the antioxidant capacity.

Detoxification and antioxidant effects of garlic and curcumin in Oreochromis niloticus injected with aflatoxin B₁ with reference to gene expression of glutathione peroxidase (GPx) by RT-PCR

The present study aims to investigate the effects of both garlic and curcumin through evaluating their therapeutic properties as antioxidants on liver and kidney functions, hepatic antioxidants and GPx gene expression against aflatoxicosis of O. niloticus. In total, 180 of tilapia were divided into ten groups; T1 represented the negative control fed on a basal diet, and T2 was injected with a single intraperitoneal (i.p.) dose of AFB1 (6 mg/kg b.w.). Fish in T3-T6 were fed on a basal diet supplemented with both garlic (T3 and T4) and curcumin (T5 and T6) at the two concentrations of 10 and 20 g/kg diet, respectively. Fish in T7-T10 groups were injected with AFB1 and fed on the garlic (T7 and T8) and curcumin (T9 and T10) dietaries. The results showed that AFB1 has significant potency for increasing the activity of plasma AST, ALT, creatinine and uric acid values, and hepatic MDA as well as for reducing the concentrations of plasma TP, AL, GL and hepatic activity of TAC, while AFB1 led to up-regulated GPx gene expression when compared to the control (T1). These harmful effects of AFB1 were alleviated due to the garlic and curcumin dietaries in some studied parameters. Garlic reflected the highest induction of gene expression (T7); however, curcumin showed significant down-regulated (T9). These results concluded that the effects of garlic were better than curcumin at the two concentrations and the low concentration of them is more beneficial than the high concentration when it used against AFB1 in O. niloticus.

Acute exposure to glyphosate herbicide affects oxidative parameters in piava (Leporinus obtusidens)

In recent years, commercial glyphosate herbicide formulations have been widely used in agriculture to control aquatic weeds. These pesticides may result in disruption of ecological balance, causing damage to nontarget organisms including fish. Teleostean fish (Leporinus obtusidens) were exposed to commercial glyphosate herbicide formulation at 0 (control), 3, 6, 10 or 20 mg L(-1) for 96 h. The effects of herbicide on plasmatic metabolic parameters, thiobarbituric acid reactive substances (TBARS), catalase activity, protein carbonyl, and mucus layer parameters were studied. Plasmatic glucose and lactate levels increased but protein levels showed reduction after herbicide exposure. TBARS levels in brain showed a reduction at all tested concentrations. However, liver demonstrated increased TBARS levels at all tested concentrations, whereas in white muscle TBARS production did not change after exposure to herbicide. Fish exposed to all concentrations of glyphosate showed increase in liver catalase activity and protein carbonyl. Herbicide exposure increased protein and carbohydrate levels of the mucus layer at all tested concentrations. The present results showed that, in 96 h, glyphosate changed toxicological parameters analyzed in piava. Parameters measured in this study may be useful in environmental biomonitoring.

Acute toxicity of carbamazepine to juvenile rainbow trout (Oncorhynchus mykiss): effects on antioxidant responses, hematological parameters and hepatic EROD

Awareness of residual pharmaceutically active compounds (PhACs) in the aquatic environment is growing as investigations into these pollutants are increasing and analytical detection techniques are improving. However, the toxicological effects of PhACs have not been adequately researched. In this study, the toxic effects of carbamazepine (CBZ), an anticonvulsant drug commonly present in surface and groundwater, was studied in juvenile rainbow trout, Oncorhynchus mykiss, by acute semi-static bioassay. Blood parameters, liver xenobiotic-metabolizing response and tissue antioxidant status were evaluated. Compared to the control group, fish exposed to CBZ (96 h LC50) showed significantly higher Er, Hb, MCHC, monocytes, neutrophil granulocytes and plasma enzymes activity, and significantly lower MCV and lymphocytes. CF and HSI were not significantly different among groups such as hepatic EROD. SOD, CAT, GPx and GR activity was significantly higher in liver of experimental groups, but decreased significantly in brain and gill. In general, antioxidant enzyme activity in intestine and muscle was less evident than in liver. Oxidative stress indices (levels of LPO and CP) were significantly higher in gill and brain, despite a trend to increased values were manifested in the remaining tissues. In short, CBZ-induced stress responses in different tissues were reflected in the oxidant stress indices and hematological parameters. However, before those parameters are used as special biomarkers for monitoring residual pharmaceuticals in aquatic environment, more detailed experiments in laboratory need to be performed in the future.

Responses of antioxidant status and Na+-K+-ATPase activity in gill of rainbow trout, Oncorhynchus mykiss, chronically treated with carbamazepine

In recent years, chemical pollution by the residual pharmaceuticals has been increasingly important issue due to its widely present in the aquatic environment. However, the toxicological effects of residual pharmaceuticals on fish have not been adequately researched. The aim of this work is to investigate the toxic effect of CBZ, an anticonvulsant drug commonly present in aquatic environment, on antioxidant status and Na+-K+-ATPase in gill of rainbow trout exposed to sublethal CBZ (1.0 microg L(-1), 0.2 mg L(-1) and 2.0 mg L(-1)) for 7, 21 and 42 d. After prolonged exposure of CBZ at higher test concentration (0.2 or 2.0 mg L(-1)), oxidative stress was apparent as reflected by the significant higher LPO and CP levels in fish gill, as well as the significant inhibition of antioxidant enzymes activities including SOD, CAT, GR and GPx. Besides, reduced glutathione level and Na+-K+-ATPase activity were significantly lower than those of the control after 42 d of exposure to CBZ at higher test concentration (0.2 or 2.0 mg L(-1)). The results of this study indicate that chronic exposure of CBZ has altered multiple physiological indices in fish gill; however, before those parameters are used as special biomarkers for monitoring residual pharmaceuticals in aquatic environment, more detailed experiments in laboratory need to be performed in the future.

Aflatoxin B1-induced DNA damage in Labeo rohita: protective effect of an antioxidant supplement, Amrita Bindu

The present study was undertaken to investigate the effect of potent hepatocarcinogen aflatoxin B1 in adduct formation and DNA damage in Labeo rohita. Also, the salubrious efficacy of an antioxidant supplement Amrita Bindu (based on Indian system of Medicine) was investigated. Fish weighing 175-250 g were administered intraperitoneally a single dose of 100 microg aflatoxin B1/100 g body wt. and another group was given 20% solution of Amrita Bindu along with aflatoxin B1 at 100 microg/100 g body wt. On the 3rd and 6th day, the liver tissue was analyzed for aflatoxin concentration, aflatoxin-DNA adduct formation and DNA damage measured in terms of single strand breaks. The fishes administered with aflatoxin B1 showed elevated concentration of aflatoxin along with a parallel increase in the DNA adduct when compared with the controls. While the fish co-administered with Amrita Bindu showed 34% and 24% reduction in aflatoxin deposition (accumulation) and aflatoxin-DNA adduct formation respectively on the 3rd day, a further reduction by around 41% and 33% in aflatoxin deposition and DNA adduct formation respectively was observed on the 6th day. Furthermore, the increased single strand breaks (measured by alkaline single cell gel assay) and fragmentation observed in agarose gel electrophoresis in aflatoxin B1 administered fish were significantly reduced by Amrita Bindu co-administration. In conclusion, this is the first report to show aflatoxin B1-induced DNA adduct formation and DNA damage in one of the major Indian culturable fish, Labeo rohita. Also, our observations show that the antioxidant supplement, Amrita Bindu, has a potential role in ameliorating the aflatoxin B1-induced DNA damage thus suggesting its applicability in preventing the vital macromolecule DNA.

Antioxidant activity of a salt-spice-herbal mixture against free radical induction

A combination of spices (Piper nigrum, Piper longum and Zingiber officinale), herbs (Cyperus rotundus and Plumbago zeylanica) and salts make up Amrita Bindu. The study was focused to evaluate the antioxidant property of individual ingredients in Amrita Bindu against the free radical 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The analysis revealed the antioxidant potential of the ingredients in the following order: Piper nigrum>Piper longum>Cyperus rotundus>Plumbago zeylanca>Zingiber officinale. Two different experiments were designed. In experiment I, rats were fed with normal diet whereas in experiment II rats were given feed mixed with Amrita Bindu for 3 weeks (4 g/kg of feed). Rats from both experimental groups were challenged against a single intraperitonial injection of phenylhydrazine (PHZ) (7.5 mg/kg body weight). At the end of 24 and 72 h, blood was analysed for free radicals and antioxidant levels. It was interesting to note that rats with Amrita Bindu pretreatment showed significantly lower levels of free radicals, lipid peroxidation and protein carbonyls along with significantly higher levels of antioxidants when compared with rats without Amrita Bindu pretreatment on PHZ administration. These results reveal that Amrita Bindu, a salt-spice-herbal mixture exerts a promising antioxidant potential against free radical induced oxidative damage.