Prevention of cardiotoxicity of aflatoxin B1 via dietary supplementation of papaya fruit extracts in rats

Effects of Aflatoxins and Fumonisins, Alone or in Combination, on Performance, Health, and Safety of Food Products of Broiler Chickens, and Mitigation Efficacy of Bentonite and Fumonisin Esterase

The current study evaluated the effects of feeding diets contaminated with aflatoxin B1 (AFB1), fumonisins (FBs), or both on the performance and health of broiler chickens and the safety of their food products as well as the efficacy of bentonite and fumonisin esterase to mitigate the effects of these mycotoxins under conditions representative for sub-Saharan Africa (SSA). Four hundred one-day-old Cobb 500 broiler chickens were randomly assigned to 20 treatments with either a control diet, a diet with moderate AFB1 (60 μg/kg feed) or high AFB1 (220 μg/kg feed), or FBs (17,430 μg FB1+FB2/kg feed), alone or in combination, a diet containing AFB1 (either 60 or 220 μg/kg) and/or FBs (17,430 μg FB1+FB2/kg) and bentonite or fumonisin esterase or both, or a diet with bentonite or fumonisin esterase only. The experimental diets were given to the birds from day 1 to day 35 of age, and the effects of the different treatments on production performance were assessed by feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR). Possible health effects were evaluated through blood biochemistry, organ weights, mortality, liver gross pathological changes, and vaccine response. Residues of aflatoxins (AFB1, B2, G1, G2, M1 and M2) were determined in plasma, muscle, and liver tissues using validated UHPLC-MS/MS methods. The results obtained indicated that broiler chickens fed high AFB1 alone had poor FCR when compared to a diet with both high AFB1 and FBs (p = 0.0063). Serum total protein and albumin from birds fed FBs only or in combination with moderate or high AFB1 or detoxifiers increased when compared to the control (p < 0.05). Liver gross pathological changes were more pronounced in birds fed contaminated diets when compared to birds fed the control or diets supplemented with mycotoxin detoxifiers. The relative weight of the heart was significantly higher in birds fed high AFB1 and FBs when compared to the control or high AFB1 only diets (p < 0.05), indicating interactions between the mycotoxins. Inclusion of bentonite in AFB1-contaminated diets offered a protective effect on the change in weights of the liver, heart and spleen (p < 0.05). Residues of AFB1 were detected above the limit of quantification (max: 0.12 ± 0.03 μg/kg) in liver samples only, from birds fed a diet with high AFB1 only or with FBs or the detoxifiers. Supplementing bentonite into these AFB1-contaminated diets reduced the levels of the liver AFB1 residues by up to 50%. Bentonite or fumonisin esterase, alone, did not affect the performance and health of broiler chickens. Thus, at the doses tested, both detoxifiers were safe and efficient for use as valid means of counteracting the negative effects of AFB1 and FBs as well as transfer of AFB1 to food products (liver) of broiler chickens.

Metabolic Disruption by Naturally Occurring Mycotoxins in Circulation: A Focus on Vascular and Bone Homeostasis Dysfunction

Naturally occurring food/feed contaminants have become a significant global issue due to animal and human health implications. Despite risk assessments and legislation setpoints on the mycotoxins' levels, exposure to lower amounts occurs, and it might affect cell homeostasis. However, the inflammatory consequences of this possible everyday exposure to toxins on the vascular microenvironment and arterial dysfunction are unexplored in detail. Circulation is the most accessible path for food-borne toxins, and the consequent metabolic and immune shifts affect systemic health, both on vascular apparatus and bone homeostasis. Their oxidative nature makes mycotoxins a plausible underlying source of low-level toxicity in the bone marrow microenvironment and arterial dysfunction. Mycotoxins could also influence the function of cardiomyocytes with possible injury to the heart. Co-occurrence of mycotoxins can modulate the metabolic pathways favoring osteoblast dysfunction and bone health losses. This review provides a novel insight into understanding the complex events of coexposure to mixed (low levels) mycotoxicosis and subsequent metabolic/immune disruptions contributing to chronic alterations in circulation.

Modulatory Effect of Papaya Extract against Chlorpyrifos-Induced Oxidative Stress, Immune Suppression, Endocrine Disruption, and DNA Damage in Female Clarias gariepinus

Chlorpyrifos (CPF) is one of the widely used organophosphorus pesticides in agriculture activities and its presence in the aquatic environment has been broadly recorded. In the present study, we investigated the effect of CPF exposure on oxidative stress, innate immunity, sexual hormones, and DNA integrity of female African catfish, Clarias gariepinus, in addition to the potential use of dietary supplementation of papaya, Carica papaya (CP), extract against CPF toxicity. Apparent healthy female catfish (300 ± 10 g) were divided into four groups with three replicates each. The first group served as the negative control (fed on a basal diet) and the other groups exposed to CPF (8.75 µg/L) with or without CP extract (250 mg/kg body weight) for six weeks. The results revealed that CPF exposure exhibited marked elevations in stress markers (glucose and cortisol), serum aspartate aminotransferase, alanine aminotransferase activities, testosterone, and luteinizing hormone level. Moreover, CPF increased the percentage of hepatic DNA damage. In addition, catfish exposed to CPF experienced significant decline in serum total protein, albumin, follicles stimulating hormone, estradiol hormone levels, AChE, immunoglobulin, and lysozyme activity. CPF induced significantly oxidative stress in hepatic and renal tissues. The dietary supplementation with CP extract at a level of 250 mg/kg body weight succeeded to alleviate the negative effects of CPF on the physiological, immunological, and antioxidant status of female catfish. In addition, CP extract alleviated the endocrine disruption and hepatic DNA damage and counteracted the subchronic CPF toxicity in female African catfish. Finally, the CP extract may be used as a feed additive in the aquatic diet.

Protective effects of methanolic leaf extracts of Monanthotaxis caffra against aflatoxin B1-induced hepatotoxicity in rats

Aflatoxins are potent hepatotoxic and carcinogenic secondary metabolites produced by toxigenic fungi. The present study investigated the protective effect of methanolic leaf extracts of Monanthotaxis caffra (MLEMC) against aflatoxin B1-induced toxicity in male Sprague-Dawley rats. The rats were randomly divided into 6 groups of 8 animals each. Five groups were administered orally for seven days with three different concentrations of MLEMC (100 mg/kg, 200 mg/kg and 300 mg/kg), curcumin (10 mg/kg) or vehicle (25% propylene glycol). The following day, these groups were administered 1 mg/kg b.w. of aflatoxin B1 (AFB1). The experiment was terminated three days after administration of AFB1. Group 6 represented untreated healthy control. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatinine and liver histopathology were evaluated. Methanolic leaf extracts of M. caffra decreased the levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and creatinine in the sera of rats as compared with the AFB1 intoxicated group. Co-administration of MLEMC improved the histological characteristics of the hepatocytes in contrast to the AFB1 treated group, which had mild to severe hepatocellular injuries including bile duct proliferation, bile duct hyperplasia, lymphoplasmacytic infiltrate and fibrosis. Extracts of M. caffra were beneficial in mitigating the hepatotoxic effects of AFB1 in rats by reducing the levels of liver enzymes and preventing hepatic injury.

Caffeic acid mitigates aflatoxin B1-mediated toxicity in the male rat reproductive system by modulating inflammatory and apoptotic responses, testicular function, and the redox-regulatory systems

Aflatoxin B1 (AFB₁ ) is a toxic metabolite of public health concern. The present study investigates the protective effects of caffeic acid (CA) against AFB₁ -induced oxidative stress, inflammation, and apoptosis in the hypothalamus, epididymis, and testis of male rats. Five experimental rat cohorts (n = 6) were treated per os for 28 consecutive days as follows: Control (Corn oil 2 ml/kg body weight), AFB1 alone (50μg/kg), CA alone (40 mg/kg) and the co-treated rat cohorts (AFB₁ : 50μg/kg + CA1: 20 or 40 mg/kg). Following sacrifice, the biomarkers of hypothalamic, epididymal, and testicular toxicities, antioxidant enzyme activities, myeloperoxidase (MPO) activity, as well as levels of nitric oxide (NO), reactive oxygen and nitrogen (RONS) species and lipid peroxidation (LPO) were analysed spectrophotometrically. Besides, the concentration of tumour necrosis factor-alpha (TNF-α), Bcl-2 and Bax proteins were assessed using ELISA. Results showed that the AFB₁ -induced decrease in biomarkers of testicular, epididymal and hypothalamic toxicity was significantly (p < .05) alleviated in rats coexposed to CA. Moreover, the reduction of antioxidant status and the increase in RONS and LPO were lessened (p < .05) in rats co-treated with CA. AFB₁ mediated increase in TNF-α, Bax, NO and MPO activity were reduced (p< .05) in the hypothalamus, epididymis, and testis of rats coexposed to CA. In addition, Bcl-2 levels were reduced in rats treated with CA dose-dependently. Light microscopic examination showed that histopathological lesions severity induced by AFB₁ were alleviated in rats coexposed to CA. Taken together, the amelioration of AFB₁ -induced neuronal and reproductive toxicities by CA involves anti-inflammatory, antioxidant, antiapoptotic mechanisms in rats. PRACTICAL APPLICATIONS: The beneficial antioxidant effects of caffeic acid (CA) are attributed to CA delocalized aromatic rings and free electrons, easily donated to stabilize reactive oxygen species. We report in vivo findings on CA and AfB1 mediated oxidative stress and reproductive dysfunction in rats. CA conjugated esters including chlorogenic acids are widely distributed in plants, and they act as a dietary source of natural defense against infections. CA can chelate heavy metals and reduce production of damaging free radicals to cellular macromolecules. Along these lines, CA can stabilize aflatoxin B1-epoxide as well and avert deleterious conjugates from forming with deoxyribonucleic acids. Hence CA, as a dietary phytochemical can protect against the damaging effects of toxins including aflatoxin B1 that contaminate food. CA dose-dependently abated oxidative, inflammatory, and apoptotic stimuli, improved functional characteristics of spermatozoa and reproductive hormone levels, and prevented histological alterations in experimental rats' hypothalamus and reproductive organs brought about by AFB1 toxicity.

In vivo effects of aflatoxin B1 and benzo[a]pyrene on the heart muscle of chicken embryos

The purpose of the present study was to evaluate the effects of aflatoxin B1 (AFB1) and benzo[a]pyrene (BaP) on the heart muscle of chicken embryos of the broiler line Ross 308. The benzo[a]pyrene in the organic oil solution was injected in ovo on the 6th day of the incubation in doses of: 0.1, 0.5, and 1 mg/kg weight of eggs; the aflatoxin B1 in the organic oil solution was injected in ovo on the 6th day of the incubation into the yolk in doses of 80, 120 and 240 ng/kg weight of eggs. Multiple biochemical and hepatic parameters have been observed, including sodium, potassium, chloride, cholesterol, uric acid, total proteins, aminotransferase aspartate, and aminotransferase alanine. A low dose of AFB1 and BaP administered in ovo during early embryonic development had a significant impact on chicken embryonic development, as demonstrated by alterations in biochemical, mineral, and hepatic parameters.

Ameliorative effects of Carica papaya extracts against type II diabetes-induced myocardial pathology and dysfunction in albino rats

Diabetes is characterized by hyperglycemia. Secondary complications of diabetes are serious risk factors that might lead to cardiovascular diseases. This study evaluated the effects of methanolic extract of Carica papaya fruit and seed in ameliorating the abnormal structural changes in myocardium and functional impairment induced by diabetes in albino rats. The experimental animals were divided into control (C), induced type II diabetes (D), protected seed extract (PSE), protected fruit extract (PFE), treated seed extract (TSE), and treated fruit extract (TFE). The myocardium of diabetic group exhibited disorganized myocardial fibers. Regard both normal, seed and fruit extract groups, which are of almost similar normal pattern of regular oriented muscle fibers. The diabetic group exhibited increased myocardial lipid peroxidation coincides with depletion of superoxide dismutase and increase of the levels of creatine kinase, troponin-1, nuclear factor Kappa B, caspase 3, tumor necrosis factor-α, and activity of lactic dehydrogenase. The diabetic group showed intense dark brown immune reaction against α-smooth muscle actin and P53. Experimental diabetic group protected with either seed and fruit extract exhibited marked amelioration of the assessed parameters. In conclusion, both seed and fruit extract of Carica papaya are of potential medical importance through managing high glucose level and keep myocardium against diabetes-induced cell death.

Selenium mitigated aflatoxin B1-induced cardiotoxicity with potential regulation of 4 selenoproteins and ferroptosis signaling in chicks

The aim of the present study was to explore the underlying mechanism of selenium (Se)-mediated detoxification of aflatoxin B₁ (AFB₁)-induced cardiotoxicity in chicks. A Se-deficient, corn-soybean meal-basal diet (36 μg Se/kg, BD) and three test diets (BD+1.0 mg AFB₁/kg, 0.3 mg Se/kg, or 1.0 mg AFB₁/kg+0.3 mg Se/kg) were used in a 3-wk 2 × 2 factorial design trial (n = 30 chicks/group). Dietary AFB₁ led to induced (P < 0.05) serum creatine kinase and creatine kinase MB isoenzyme activities and heart histopathologic lesions. However, Se deficiency aggravated most of these alterations induced by AFB₁. Moreover, mRNA levels of two ferroptosis activators (solute carrier family 11 Member 2 and transferrin) were upregulated (P < 0.05) in the AFB₁-treated groups. Additionally, Se deficiency reduced (P < 0.05) glutathione peroxidase (GPX) 3 and thioredoxin reductase 3 mRNA and GPX activity but increased (P < 0.05) selenoprotein M and selenophosphate synthetase 2 mRNA in the heart in AFB₁-administered groups. The in vitro study showed that Se alleviated (P < 0.05) AFB₁-reduced cell viability and induced (P < 0.05) ROS and ferroptosis in H9C2 cardiac cells. It also downregulated (P < 0.05) two ferroptosis activators (long-chain acyl-CoA synthetase 4 and solute carrier family 11 Member 2) in the AFB₁-treated groups in the H9C2 cells. In conclusion, this study illustrated that Se alleviates AFB₁-induced cardiotoxicity and cardiomyocyte damage potentially related to the regulation of redox status, 4 selenoproteins, and ferroptosis-related signaling.

Fluorescence Spectroscopic Investigation of Competitive Interactions between Quercetin and Aflatoxin B₁ for Binding to Human Serum Albumin

Aflatoxin B₁ (AFB₁) is a highly toxic mycotoxin found worldwide in cereals, food, and animal feeds. AFB₁ binds to human serum albumin (HSA) with high affinity. In previous experiments, it has been revealed that reducing the binding rate of AFB₁ with HSA could speed up the elimination rate of AFB₁. Therefore, we examined the ability of quercetin to compete with AFB₁ for binding HSA by fluorescence spectroscopy, synchronous spectroscopy, ultrafiltration studies, etc. It was shown that AFB₁ and quercetin bind to HSA in the same Sudlow site Ӏ (subdomain IIA), and the binding constant (K_a) of the quercetin-HSA complex is significantly stronger than the complex of AFB₁-HSA. Our data in this experiment showed that quercetin is able to remove the AFB₁ from HSA and reduce its bound fraction. This exploratory work may be of significance for studies in the future regarding decreasing its bound fraction and then increasing its elimination rate for detoxification. This exploratory study may initiate future epidemiological research designs to obtain further in vivo evidence of the long-term (potential protective) effects of competing substances on human patients.

Protective effects of curcumin against aflatoxicosis: A comprehensive review

Aflatoxicosis is a deleterious medical condition that results from aflatoxins (AFs) or ochratoxins (OTs). Contamination with these toxins exerts detrimental effects on the liver, kidneys, reproductive organs, and also on immunological and cardiovascular systems. Aflatoxicosis is closely associated with overproduction of reactive oxygen species (ROS) as key contributors to oxidative and nitrosative stress responses, and subsequent damages to lipids, proteins, RNA, and DNA. The main target organ for AF toxicity is the liver, where DNA adducts, degranulation of endoplasmic reticulum, increased hepatic lipid peroxide, GSH depletion, mitochondrial dysfunction, and reduction of enzymatic and non-enzymatic antioxidants are manifestations of aflatoxicosis. Curcuma longa L. (turmeric) is a medicinal plant widely utilized all over the world for culinary and phytomedical purposes. Considering the antioxidant characteristic of curcumin, the main active component of turmeric, this review is intended to critically summarize the available evidence supporting possible effectiveness of curcumin against aflatoxicosis. Curcumin can serve as a promising candidate for attenuation of the adverse consequences of aflatoxicosis, acting mainly through intrinsic antioxidant effects aroused from its structure, modulation of the immune system as reflected by interleukin-1β and transforming growth factor-β, and interfering with AF's biotransformation by cytochrome P450 isoenzymes CYP1A, CYP3A, CYP2A, CYP2B, and CYP2C.

Assessment of aflatoxin B1 myocardial toxicity in rats: mitochondrial damage and cellular apoptosis in cardiomyocytes induced by aflatoxin B1

Objective

The number of deaths from heart disease is increasing worldwide. Aflatoxin B1 (AFB1), a toxin produced by the fungi Aspergillus flavus and Aspergillus parasiticus, is frequently detected in improperly processed/stored human food products. While AFB1 hepatotoxicity and carcinogenic properties have been well addressed, its myocardial toxicity is poorly documented. This study aimed to investigate myocardial toxic activity of AFB1.

Methods

Ten rats were fed with AFB1 at a dose that did not result in acute toxic reactions for 30 days and 10 vehicle-fed rats served as controls. Transmission electron microscopy was used to assess mitochondrial damage in cardiomyocytes. The terminal deoxynucleotidyl transferase-mediated UTP nick-end labelling assay was performed to detect apoptosis of cardiomyocytes. Western blotting was performed to measure apoptotic proteins (i.e., active caspase-3, Bax, and Bcl-2) in heart tissue.

Results

AFB1 treatment resulted in mitochondrial membrane disruption and disorganization of cristae, which are indicators of mitochondrial damage. Myocardial cell apoptosis was significantly higher after AFB1 treatment (22.07% ± 3.29%) compared with controls (6.27% ± 2.78%, P < 0.05). AFB1 treatment enhanced expression of active caspase-3, Bax, and Bcl-2 in cardiac tissue.

Conclusion

Various adverse effects are exerted by AFB1 on the heart, indicating AFB1 myocardial toxicity.

Pharmacological basis for the medicinal use of polyherbal formulation and its ingredients in cardiovascular disorders using rodents

BACKGROUND

A compound herbal formulation (POL4) has been used in the indigenous system of medicine to treat cardiometabolic disorders like diabetes and associated hypertension. POL4 and most of its constituents have not been studied widely for its therapeutic use in hypertension. This study is aimed to determine the efficacy and possible insight into mechanism(s) for the medicinal use of POL4 and its ingredients in hypertension.

METHODS

The aqueous methanolic extracts of POL4 (POL4.Cr) and its components [Cichorium intybus (Ci.Cr), Gymnema sylvestre (Gs.Cr), Nigella sativa (Ns.Cr) and Trigonella foenum graecum (Tfg.Cr)] were tested for blood pressure lowering activity in anaesthetized Sprague-Dawley rats. To assess the vasomodulatory effect, isolated tissue experiments were performed on rat aortic strips using isometric force transducer coupled with PowerLab data acquisition system.

RESULTS

Administration of POL4 to rats caused a dose-dependent (1-100 mg/kg) fall in mean arterial pressure (MAP) with maximum effect of 85.33 ± 1.76% at 100 mg/kg, similar to the effect of verapamil. All ingredients of POL4 also decreased blood pressure with varying efficacy in following order Ns.Cr ≅ Ci.Cr > Tfg.Cr > Gs.Cr. In rat aortic preparations, POL4 and its ingredients inhibited K+ (80 mM)-induced contractions, Ci.Cr was the most potent followed by Ns.Cr > Tfg.Cr > Gs.Cr ≅ POL4. Against phenylephrine (P.E) contractions, Ci.Cr and Tfg.Cr exhibited complete relaxation, while POL4.Cr, Gs.Cr and Ns.Cr showed vasomodulatory effect. The Ca++ antagonist activity was confirmed when POL4 and its ingredients shifted Ca++ concentrations-response curves to the right in a manner similar to that of verapamil. On baseline of rat aorta, the parent formulation and its ingredients (except Tfg.Cr) exhibited partially phentolamine (1 μM)-sensitive vasoconstriction.

CONCLUSION

These data show that POL4 and its constituents possess blood pressure lowering activity mediated through inhibition of Ca++ influx via membranous Ca++ channels and receptor (α-adrenergic) operated pathways. Thus, this study provides a rationale to the medicinal use of POL4 and its constituents in hypertension.