Ginger extract modulates Pb-induced hepatic oxidative stress and expression of antioxidant gene transcripts in rat liver

Impact of plant extracts on hepatic redox metabolism upon lead exposure: a systematic review of preclinical in vivo evidence

The liver is a central target organ of heavy metals toxicity, and secondary metabolites of several plant species are suggested to attenuate lead (Pb)-induced hepatotoxicity through antioxidant and anti-inflammatory mechanisms. We used a systematic review framework to map the impact of plant extracts and bioactive secondary metabolites on immunological markers and liver redox metabolism in preclinical models of Pb exposure. This is a systematic review performed according to PRISMA guidelines. The structured research of publications was done through PubMed, Scopus, Web of Science, and Embase databases, selecting and analyzing 41 original studies included via the eligibility criteria. Evidence indicates that Pb-exposure increases reactive oxygen/nitrogen species (ROS/RNS) production by δ-aminolevulinic acid auto-oxidation, xanthine dehydrogenase, and xanthine oxidase upregulation. Pb exposure also inhibits antioxidant enzymes, potentiating ROS/NOS levels and reactive cell damage. Plant extracts rich in flavonoids, tannins, alkaloids, anthocyanins, and vitamins exerted hepatoprotective effects by chelating and decreasing Pb bioaccumulation. In addition, plant extracts reinforce exogenous and endogenous antioxidant defenses, attenuating liver oxidative stress and cell death. The lack of blinded evaluators and randomized experimental groups were the main sources of bias identified, which need to be controlled in toxicological studies aimed at identifying natural products applied to the prevention or treatment of Pb poisoning.

Selenium and vitamin E ameliorate lead acetate-induced hepatotoxicity in rats via suppression of oxidative stress, mRNA of heat shock proteins, and NF-kB production

BACKGROUND

Lead exposure results in a terrible rise in heat shock protein levels.

OBJECTIVE

This research was conducted to look at the effects of lead poisoning on heat shock response, oxidative stress, and inflammatory markers in albino rats, as well as the power of selenium and vitamin E to resist lead toxic effects.

METHODS

Eight groups of albino rats are used. Each group contained six rats where the first group represented the negative control, and the other groups were treated with olive oil, vitamin E, selenium, lead, (vitamin E + lead), (selenium + lead), and (vitamin E + selenium + lead). All the treatments lasted for 28 days. Then, the mRNA expression of interested heat shock proteins (HSP90, HSP70, and HSP60) was assessed. For oxidative stress disruption, we investigated nitric oxide (NO) and malondialdehyde (MDA) content, and enzymatic and non-enzymatic antioxidants activity respectively in rat livers.

RESULTS

our results revealed the synergetic protective effect of the combination of two antioxidants (vitamin E and selenium) against lead poising. This was clear in regulating HSPs expression, inflammatory markers, glucose, lipid profile, liver functions, and antioxidant enzymes more than the treatment with one antioxidant.

CONCLUSION

Pb is a toxic material that can induce HSPs and inflammatory markers expression. Selenium and vitamin E can give excellent effects in ameliorating Pb toxicity when used together.

Improving hydrocarbon toxicity tolerance in poultry: role of genes and antioxidants

Sustenance of smallholder poultry production as an alternative source of food security and income is imperative in communities exposed to hydrocarbon pollution. Exposure to hydrocarbon pollutants causes disruption of homeostasis, thereby compromising the genetic potential of the birds. Oxidative stress-mediated dysfunction of the cellular membrane is a contributing factor in the mechanism of hydrocarbon toxicity. Epidemiological studies show that tolerance to hydrocarbon exposure may be caused by the activation of genes that control disease defense pathways like aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2p45-related factor 2 (Nrf2). Disparity in the mechanism and level of tolerance to hydrocarbon fragments among species may exist and may result in variations in gene expression within individuals of the same species upon exposure. Genomic variability is critical for adaptation and serves as a survival mechanism in response to environmental pollutants. Understanding the interplay of diverse genetic mechanisms in relation to environmental influences is important for exploiting the differences in various genetic variants. Protection against pollutant-induced physiological responses using dietary antioxidants can mitigate homeostasis disruptions. Such intervention may initiate epigenetic modulation relevant to gene expression of hydrocarbon tolerance, enhancing productivity, and possibly future development of hydrocarbon-tolerant breeds.

Ginger for Healthy Ageing: A Systematic Review on Current Evidence of Its Antioxidant, Anti-Inflammatory, and Anticancer Properties

The world's population is ageing at an accelerated pace. Ageing is a natural, physiological but highly complex and multifactorial process that all species in the Tree of Life experience over time. Physical and mental disabilities, and age-related diseases, would increase along with the increasing life expectancy. Ginger (Zingiber officinale) is a plant that belongs to the Zingiberaceae family, native to Southeast Asia. For hundreds of years, ginger has been consumed in various ways by the natives of Asian countries, both as culinary and medicinal herb for the treatment of many diseases. Mounting evidence suggests that ginger can promote healthy ageing, reduce morbidity, and prolong healthy lifespan. Ginger, a well-known natural product, has been demonstrated to possess antioxidant, anti-inflammatory, anticancer, and antimicrobial properties, as well as an outstanding antiviral activity due to a high concentration of antiviral compounds. In this review, the current evidence on the potential role of ginger and its active compounds in the prevention of ageing is discussed.

The Effect of 6-gingerol on Growth Factors and Apoptosis Indices in Rats Exposed to Gold Nanoparticles

Introduction

Research has shown that gold nanoparticles (AuNPs) can damage the physiological processes of brain tissue. Given the antioxidant properties of Gingerol (GING), this study aimed to determine the protective effect of 6-gingerol on hippocampal levels of Brain-Derived Neurotrophic Factor (BDNF), Nerve Growth Factor (NGF), DNA oxidative damage, and the amount of Bax and Bcl2 apoptosis indices of rats exposed to AuNPs.

Methods

A total of 42 male Wistar rats were divided into four groups: control (30 days 0.5 mL saline), AuNPs (one time injection of 0.5 mL AuNPs, 200 ppm and 60 Nm + 30 days 0.5 mL saline), AuNPs+GING 50 (one time injection of 0.5 mL AuNPs, 200 ppm and 60 Nm + 30 days 0.5 mL density of gingerol 50 mg/kg), and AuNPs+GING100 (one time injection of 0.5 mL AuNPs, 200 ppm and 60 Nm + 30 days 0.5 mL density of gingerol 100 mg/kg). At the end of the treatment period, the hippocampal levels of NGF, BDNF, 8-hydroxy-desoxyguanosine (8-HOdG), and apoptotic indices of Bax and Bcl-2 were assessed with the ELISA method.

Results

Compared with the AuNPs group, hippocampal levels of BDNF, NGF, and Bcl-2 in rats in the AuNPs+GING 50 and AuNPs+GING 100 groups significantly increased dose-dependently. However, the hippocampal levels of Bax and 8-HOdG significantly decreased dose-dependently (P<0.05).

Conclusion

According to obtained results, gingerol may improve hippocampal BDNF and NGF levels in rats exposed to AuNPs, probably by reducing apoptosis and oxidative DNA damage.

Pharmacology of Natural Volatiles and Essential Oils in Food, Therapy, and Disease Prophylaxis

This commentary critically examines the modern paradigm of natural volatiles in 'medical aromatherapy', first by explaining the semantics of natural volatiles in health, then by addressing chemophenetic challenges to authenticity or reproducibility, and finally by elaborating on pharmacokinetic and pharmacodynamic processes in food, therapy, and disease prophylaxis. Research over the last 50 years has generated substantial knowledge of the chemical diversity of volatiles, and their strengths and weaknesses as antimicrobial agents. However, due to modest in vitro outcomes, the emphasis has shifted toward the ability to synergise or potentiate non-volatile natural or pharmaceutical drugs, and to modulate gene expression by binding to the lipophilic domain of mammalian cell receptors. Because essential oils and natural volatiles are small and lipophilic, they demonstrate high skin penetrating abilities when suitably encapsulated, or if derived from a dietary item they bioaccumulate in fatty tissues in the body. In the skin or body, they may synergise or drive de novo therapeutic outcomes that range from anti-inflammatory effects through to insulin sensitisation, dermal rejuvenation, keratinocyte migration, upregulation of hair follicle bulb stem cells or complementation of anti-cancer therapies. Taking all this into consideration, volatile organic compounds should be examined as candidates for prophylaxis of cardiovascular disease. Considering the modern understanding of biology, the science of natural volatiles may need to be revisited in the context of health and nutrition.

Plant Polyphenols: Potential Antidotes for Lead Exposure

Lead is one of the most common heavy metal elements and has high biological toxicity. Long-term lead exposure will induce the contamination of animal feed, water, and food, which can cause chronic lead poisoning including nephrotoxicity, hepatotoxicity, neurotoxicity, and reproductive toxicity in humans and animals. In the past few decades, lead has caused widespread concern because of its significant threat to health. A large number of in vitro and animal experiments have shown that oxidative stress plays a key role in lead toxicity, and endoplasmic reticulum (ER) stress and the mitochondrial apoptosis pathway can also be induced by lead toxicity. Therefore, plant polyphenols have attracted attention, with their advantages of being natural antioxidants and having low toxicity. Plant polyphenols can resist lead toxicity by chelating lead with their special chemical molecular structure. In addition, scavenging active oxygen and improving the level of antioxidant enzymes, anti-inflammatory, and anti-apoptosis are also the key to relieving lead poisoning by plant polyphenols. Various plant polyphenols have been suggested to be useful in alleviating lead toxicity in animals and humans and are believed to have good application prospects.

Therapeutic influences of almond oil on male rats exposed to a sublethal concentration of lead

Globally, human exposure to heavy metals has risen dramatically. Lead (Pb) is one of the most toxic heavy metals to human and other living organisms. Pb affects certain biochemical and physiological activities of the body. Many scientific investigations have documented the therapeutic and antioxidant properties of natural products which isolated from plant sources. The present study was therefore undertaken to evaluate the therapeutic influence of almond oil against Pb toxicity in male rats. The experimental rats were distributed into four groups. The first group was served as control. The second group was treated with 100 mg/kg body weight of Pb. The third group was subjected to almond oil (800 mg/kg body weight) and Pb. The fourth group was supplemented with almond oil. After six weeks, blood serum specimens were analyzed. In the second group, Pb produced a marked increase of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total bilirubin, glucose, triglycerides, low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), creatine kinase (CK), lactate dehydrogenase (LDH), creatinine, blood urea nitrogen (BUN), uric acid and malondialdehyde (MDA) levels, while the levels of total protein, albumin, high density lipoprotein cholesterol (HDL-C), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were significantly decreased. In contrast, the treatment with almond oil notably improved the biochemical changes and showed antioxidative effect. The present study disclosed the therapeutic influence of almond oil on the basis of its antioxidant effect against Pb toxicity. Moreover, these new findings indicated that the constituents of almond oil have a promising significant potential in biomedical and pharmacological studies.

Antagonistic Efficacy of Luteolin against Lead Acetate Exposure-Associated with Hepatotoxicity is Mediated via Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Activities

The abundant use of lead (Pb; toxic heavy metal) worldwide has increased occupational and ecosystem exposure, with subsequent negative health effects. The flavonoid luteolin (LUT) found in many natural foodstuffs possesses antioxidant and anti-inflammatory properties. Herein, we hypothesized that LUT could mitigate liver damage induced by exposure to lead acetate (PbAc). Male Wistar rats were allocated to four groups: control group received normal saline, LUT-treated group (50 mg/kg, oral, daily), PbAc-treated group (20 mg/kg, i.p., daily), and LUT+PbAc-treated group (received the aforementioned doses via the respective routes of administration); the rats were treated for 7 days. The results revealed that PbAc exposure significantly increased hepatic Pb residue and serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin value. Oxidative reactions were observed in the liver tissue following PbAc intoxication, characterized by the depletion and downregulation of antioxidant proteins (glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase, catalase, nuclear factor erythroid 2-related factor 2, and heme oxygenase-1), and an increase in oxidants (malondialdehyde and nitric oxide). Additionally, PbAc increased the release and expression of the pro-inflammatory cytokines (tumor necrosis factor alpha and interleukin-1 beta), inducible nitric oxide synthase, and nuclear factor kappa B. Moreover, PbAc enhanced hepatocyte loss by increasing the expression of pro-apoptotic proteins (Bax and caspase-3) and downregulating the anti-apoptotic protein (Bcl-2). The changes in the aforementioned parameters were further confirmed by noticeable histopathological lesions. LUT supplementation significantly reversed all of the tested parameters in comparison with the PbAc-exposed group. In conclusion, our findings describe the potential mechanisms involved in the alleviation of PbAc-induced liver injury by luteolin via its potent anti-inflammatory, antioxidant, and anti-apoptotic properties.

L-α-Phosphatidylcholine attenuates mercury-induced hepato-renal damage through suppressing oxidative stress and inflammation

The potential ameliorative effects of L-α-phosphatidylcholine (PC) against mercuric chloride (HgCl₂)-induced hematological and hepato-renal damage were investigated. Rats were randomly allocated into four groups (n = 12): control, PC (100 mg/kg bwt, intragastrically every other day for 30 consecutive days), HgCl₂ (5 mg/kg bwt, intragastrically daily), and PC plus HgCl₂. Hematological and hepato-renal dysfunctions were evaluated biochemically and histopathologically. Hepatic and renal oxidative/antioxidative indices were evaluated. The expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) was also detected by ELISA. HgCl₂ significantly increased serum aminotransferases (ALT, AST), urea, and creatinine levels that are indicative of hepato-renal damage. HgCl₂ also induced a significant accumulation of malondialdehyde (+ 195%) with depletion of glutathione (- 43%) levels in the liver and renal tissues. The apparent hepato-renal oxidative damage was associated with obvious organ dysfunction that was confirmed by impairments in the liver and kidney histoarchitecture. Furthermore, HgCl₂ significantly attenuated the expression of proinflammatory cytokines named tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Conversely, PC treatment attenuated these effects, which improved the hematological and serum biochemical alternations, reduced the oxidative stress and proinflammatory cytokine levels, and ameliorated the intensity of the histopathological alterations in livers and kidneys of HgCl₂-treated rats. It could be concluded that PC displayed potential anti-inflammatory and antioxidant activities against HgCl₂-induced hepato-renal damage via suppression of proinflammatory cytokines and declining oxidative stress.

Immunomodulatory effects of Rhodomyrtus tomentosa leaf extract and its derivative compound, rhodomyrtone, on head kidney macrophages of rainbow trout (Oncorhynchus mykiss)

Rhodomyrtus tomentosa is a medicinal plant that shows biological effects including immunomodulatory activity on human and other mammals but not in fish. In this study, we evaluated the in vitro immunomodulatory effects of R. tomentosa leaf extract and its active compound, rhodomyrtone, on the immune responses, using rainbow trout (Oncorhynchus mykiss) head kidney (HK) macrophages as a model. The tested immune functions included the expression of genes involved in innate immune and inflammatory responses and the production of reactive oxygen species (ROS). Gene expression was evaluated after exposure to 10 μg mL^-1 of R. tomentosa and 1 μg mL^-1 of rhodomyrtone for 4 and 24 h. R. tomentosa and rhodomyrtone induced changes in the expression of pro-inflammatory cytokines (il1β, il8, and tnfα), anti-inflammatory cytokines (il10 and tgfβ), inducible enzymes (inos, cox2, and arginase), and an antioxidant enzyme (gpx1). Co-exposure of R. tomentosa with LPS resulted in a prominent reduction in the expression of genes related to an inflammatory process (il1β, il8, tnfα, inos, saa, hepcidin, and gpx1), suggesting anti-inflammatory effects. Similarly, co-exposure of rhodomyrtone with LPS led to a downregulation of inflammation-related genes (il1β, inos, saa, and hepcidin). In addition, exposure to both natural plant products caused a reduction in cellular ROS levels by HK macrophages. The present results indicate that R. tomentosa and rhodomyrtone exerted immunostimulatory and anti-inflammatory effects on fish macrophages, thus opening up the possibility of using these natural products to further develop immunostimulants for health management in aquaculture.

Comparative analysis of the protective effects of curcumin and N-acetyl cysteine against paracetamol-induced hepatic, renal, and testicular toxicity in Wistar rats

This study aimed to investigate the possible protective role of curcumin (CUR) vs. N-acetyl cysteine (NAC) against paracetamol (PCM)-induced oxidative damage and impairment of liver, kidney, and testicular functions, as well as hematotoxicity, in albino rats. A large single dose of PCM induced lipid peroxidation along with a significant decline in glutathione content and catalase activity in the liver, kidneys, and testicles. The apparent oxidative damage was associated with evident hepatic, renal, and testicular dysfunction, which was confirmed in histopathological lesions, and increased serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. PCM decreased serum total protein, albumin, and globulin contents; increased bilirubin, urea, and creatinine contents; and induced hematotoxicity. PCM also reduced the sperm cell count, sperm motility, and alive sperm rate and increased the sperm abnormality rate. Pretreatment of PCM-intoxicated animals with CUR or NAC substantially alleviated the increase in malondialdehyde and maintained the antioxidants at control levels. These pretreatments also minimized liver, kidney, and testicular histopathological changes and normalized their functions. CUR similarly mitigated the PCM hemato- and hepatotoxicity compared with NAC. However, it exhibited a pronounced nephroprotection, rather than reproductive protection as did NAC. Our findings demonstrate that a large single dose of PCM is not only associated with hepatotoxicity but also nephrotoxicity and reproductive toxicity. Both CUR and NAC administration provided substantial organ protection with pronounced efficacy against PCM nephrotoxicity with CUR and reproductive toxicity with NAC, which was possibly mediated through their antioxidant activities, as well as their specific characteristics.

Efficacy of α-lipoic acid against cadmium toxicity on metal ion and oxidative imbalance, and expression of metallothionein and antioxidant genes in rabbit brain

To explore the protective efficacy of α-lipoic acid (ALA) against Cd-prompted neurotoxicity, young male New Zealand rabbits (Oryctolagus cuniculus) were divided randomly into four groups. Group 1 (control) received demineralized water. Group 2 (Cd) administered cadmium chloride (CdCl₂) 3 mg/kg bwt. Group 3 (ALA) administered ALA 100 mg/kg bwt. Group 4 (Cd + ALA) administered ALA 1 h after Cd. The treatments were administered orally for 30 consecutive days. Cd-induced marked disturbances in neurochemical parameters were indicated by the reduction in micro- and macro-elements (Zn, Fe, Cu, P, and Ca), with the highest reduction in Cd-exposed rabbits, followed by Cd + ALA group and then ALA group. In the brain tissues, Cd has significantly augmented the lipid hydroperoxides (LPO) and reduced the glutathione (GSH) and total antioxidant capacity (TAC), and glutathione peroxidase and glutathione S-transferase enzyme activities but had an insignificant effect on the antioxidant redox enzymes. Administration of ALA effectively restored LPO and sustained GSH and TAC contents. Moreover, Cd downregulated the transcriptional levels of Nrf2, MT3, and SOD1 genes, and upregulated that of Keap1 gene. ALA treatment, shortly following Cd exposure, downregulated Keap1, and upregulated Nrf2 and GPx1, while maintained MT3 and SOD1 mRNA gene expression in the rabbits' brain. These data indicated the ALA effectiveness in protecting against Cd-induced oxidative stress and the depletion of cellular antioxidants in the brain of rabbits perhaps due to its antioxidant, free radical scavenging, and chelating properties.

Effects of ginger and its pungent constituents on transient receptor potential channels

Ginger extract is used as an analeptic in herbal medicine and has been reported to exert antioxidant effects. Transient receptor potential (TRP) canonical 5 (TRPC5), TRP cation channel, subfamily M, member 7 (TRPM7; melastatin 7), and TRP cation channel, subfamily A, member 1 (TRPA1; ankyrin 1) are non-selective cation channels that are modulated by reactive oxygen/nitrogen species (ROS/RNS) and subsequently control various cellular processes. The aim of this study was to evaluate whether ginger and its pungent constituents modulate these channels and exert antioxidant effects. It was found that TRPC5 and TRPA1 currents were modulated by ginger extract and by its pungent constituents, [6]-gingerol, zingerone and [6]-shogaol. In particular, [6]-shogaol markedly and dose-dependently inhibited TRPC5 currents with an IC50 of value of ~18.3 µM. Furthermore, the strong dose-dependent activation of TRPA1 currents by [6]-shogaol was abolished by A‑967079 (a selective TRPA1 inhibitor). However, ginger extract and its pungent constituents had no effect on TRPM7 currents. These results suggest the antioxidant effects of ginger extract and its pungent constituents are mediated through TRPC5 and TRPA1, and that [6]-shogaol is predominantly responsible for the regulation of TRPC5 and TRPA1 currents by ginger extract.

Attenuative role of mangiferin in oxidative stress-mediated liver dysfunction in arsenic-intoxicated murines

Mangiferin (MAG), a natural xanthone mainly derived from mangoes, possesses great antioxidative potentials. The present study has been carried out to investigate the hepato-protective role of MAG, against arsenic (As)-induced oxidative damages in the murine liver. As, a well-known toxic metalloid, is ubiquitously found in nature and has been reported to affect nearly all the organs of the human body via oxidative impairment. Administration of As in the form of sodium arsenite (NaAsO2 ) at a dose of 10 mg/kg body weight for 3 months abruptly increased reactive oxygen species (ROS) level, led to oxidative stress and significantly depleted the first line of antioxidant defense system in the body. Moreover, As caused apoptosis in hepatocytes. Treatment with MAG at a dose of 40 mg/kg for body weight for 30 days simultaneously and separately after NaAsO2 administration decreased the ROS production and attenuated the alterations in the activities of all antioxidant indices. MAG also protected liver against the NaAsO2 -induced apoptosis and disintegrated hepatocytes, thus counteracting with As-induced toxicity. It could significantly inhibit the expression of different proapoptotic caspases and upregulate the expression of survival molecules such as Akt and Nrf2. On inhibiting Akt (by PI3K inhibitor, LY294002) and ERK1/2 (by ERK1/2 inhibitor, PD98059) specifically, caspase 3 got activated abolishing mangiferin's protective role on As-induced hepatotoxicity. So here, we have briefly elucidated the signaling cascades involved in As-induced apoptotic cell death in the liver and also the detailed cellular mechanism by which MAG provides protection to this organ. © 2016 BioFactors, 42(5):515-532, 2016.

Indigofera oblongifolia Prevents Lead Acetate-Induced Hepatotoxicity, Oxidative Stress, Fibrosis and Apoptosis in Rats

The current study was aimed to evaluate the preventive effects of Indigofera oblongifolia leaf extract (IOLE) on lead acetate (PbAc)-induced hepatotoxicity in adult male Wistar rats. PbAc was intraperitoneally injected at a dose of 20 mg/kg body weight for 5 days alone or in combination with the IOLE (100 mg/kg). Liver lead concentration and oxidative stress markers such as lipid peroxidation, hydrogen peroxide, nitric oxide, and glutathione content were investigated in addition to the enzymatic antioxidant activities. PbAc injection caused a significant elevation in the liver function parameters, lead level, lipid peroxidation, hydrogen peroxide, and nitric oxide, with a concomitant decline in the glutathione content compared with the control, accompanied by a significant inhibition of antioxidant enzyme activities. The induction of oxidative stress, lead accumulation, and histological alterations in the liver were successfully minimized by pre-administration of IOLE. In addition, the PbAc group showed increase in the levels of Bax, caspase-3, and matrix metalloproteinase-9 proteins, while the expression of Bcl-2 protein was decreased. Prior administration of IOLE significantly mitigated apoptosis and fibrosis in the liver. Finally, the major components in I. oblongifolia extract were identified as polyphenols, flavonoids, and organic acids using liquid chromatography coupled mass spectroscopy. Thus, the findings of the current study revealed that I. oblongifolia had protective, anti-fibrotic, antioxidant, and anti-apoptotic activities on PbAc-induced hepatotoxicity. The beneficial effects of I. oblongifolia were in part mediated by Nrf2/HO-1 pathway.

Vitamin C modulates cadmium-induced hepatic antioxidants' gene transcripts and toxicopathic changes in Nile tilapia, Oreochromis niloticus

Cadmium (Cd) is one of the naturally occurring heavy metals having adverse effects, while vitamin C (L-ascorbic acid) is an essential micronutrient for fish, which can attenuate tissue damage owing to its chain-breaking antioxidant and free radical scavenger properties. The adult Nile tilapia fish were exposed to Cd at 5 mg/l with and without vitamin C (500 mg/kg diet) for 45 days in addition to negative and positive controls fed with the basal diet and basal diet supplemented with vitamin C, respectively. Hepatic relative mRNA expression of genes involved in antioxidant function, metallothionein (MT), glutathione S-transferase (GST-α1), and glutathione peroxidase (GPx1), was assessed using real-time reverse transcription polymerase chain reaction (RT-PCR). Hepatic architecture was also histopathologically examined. Tilapia exposed to Cd exhibited upregulated antioxidants' gene transcript levels, GST-⍺1, GPx1, and MT by 6.10-, 4.60-, and 4.29-fold, respectively. Histopathologically, Cd caused severe hepatic changes of multifocal hepatocellular and pancreatic acinar necrosis, and lytic hepatocytes infiltrated with eosinophilic granular cells. Co-treatment of Cd-exposed fish with vitamin C overexpressed antioxidant enzyme-related genes, GST-⍺1 (16.26-fold) and GPx1 (18.68-fold), and maintained the expression of MT gene close to control (1.07-fold), averting the toxicopathic lesions induced by Cd. These results suggested that vitamin C has the potential to protect Nile tilapia from Cd hepatotoxicity via sustaining hepatic antioxidants' genes transcripts and normal histoarchitecture.