Ameliorated effects of green tea extract on lead induced liver toxicity in rats

Protective Role of Myricetin and Fisetin Against Nephrotoxicity Caused by Lead Acetate Exposure through Up-regulation of Nrf2/HO-1 Signalling Pathway

The effect of various flavonoids against oxidative stress and inflammation caused by lead exposure has been investigated. However, the protective effects of myricetin (MYC) and fisetin (FST), which are known to have potent antioxidant properties, against nephrotoxicity caused by exposure to lead acetate (LA), the water-soluble form of lead, have not been investigated. Our study investigated the protective role of these flavonoids against LA intoxication-induced nephrotoxicity. In our study, 42 male rats were used. The rats were randomly selected and divided into 6 groups. These groups were: control, LA (100 g/kg), LA + MYC (100 mg/kg), LA + MYC (200 mg/kg), LA + FST (100 mg/kg) and LA + FST (200 mg/kg). All chemicals were administered daily by gavage for 28 days. According to the experimental protocol, the animals were sacrificed and their kidney tissues were isolated. Serum biochemical parameters, histological examinations, levels of several trace elements, oxidative stress and inflammatory parameters at both biochemical and molecular levels in kidney tissues were examined. After LA administration, tissue lead levels increased and zinc levels decreased. This situation was reversed by MYC and FST treatment. Oxidative stress and inflammatory response were increased in the kidney tissue of LA-treated rats and renal function was impaired. It was observed that both doses of MYC and high dose of FST could prevent nephrotoxicity. Oral administration of both doses of MYC and high dose FST ameliorated the changes in biochemical, oxidative and inflammatory parameters. Restoration of normal renal tissue architecture was also demonstrated by histological studies. MYC and FST were found to have promising biological activity against LA-induced nephrotoxicity, acting by attenuating inflammation and oxidative stress and improving antioxidant status.

Ameliorative effect of Ononis natrix against chronic lead poisoning in mice: neurobehavioral, biochemical, and histological study

Lead (Pb) is one of the most common heavy metals with toxicological effects on many tissues in humans as well as animals. In order to counteract the toxic effects of this metal, the administration of synthetic or natural antioxidants is thus required. The aim of this study was to examine the beneficial effect of the aqueous extract of Ononis natrix (AEON) against lead acetate-induced damage from a behavioral, biochemical, and histological point of view. Forty-eight male mice were divided into four equal groups: Ctr (control); Pb (lead acetate 1g/l); Pb + On 100 mg/kg (lead acetate 1 g/l + AEON 100 mg/kg); Pb + On 500 mg/kg (lead acetate 1 g/l + AEON 500 mg/kg). AEON was administered orally from day 21 after the start of lead exposure up to the end of the experiment. The results revealed that lead induced behavioral disorders, increased serum levels of liver markers (AST, ALT, and bilirubin), as well as kidney markers (urea and creatinine). At the same time, levels of thiobarbituric acid reactive substances (TBARS) and glutathione peroxidase (GPx) increased significantly. Moreover, Pb caused structural changes in the liver and kidneys of Pb-exposed mice. However, AEON administration significantly improved all lead-induced brain, liver, and kidney dysfunctions. Our results suggest that AEON could be a source of molecules with therapeutic potential against brain, liver, and kidney abnormalities caused by lead exposure.

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.

High Levels of Heavy Metal(loid)s Related to Biliary Hyperplasia in Hedgehogs (Erinaceus europaeus)

Heavy metal(loid) pollution of ecosystems is a current One Health problem. The liver is one of the most affected organs in cases of acute or chronic exposure to abnormal amounts of these substances, inducing histopathologic lesions. In order to assess the influence of heavy metal(loids), forty-five European hedgehogs (Erinaceus europaeus) were submitted to necropsy, and liver samples were collected for a routine histopathology exam and metal(loid)s determination (As, Cd, Co, Cr, Cu and Pb) by ICP-MS. Age was estimated during the necropsy exam. Biliary hyperplasia was the most frequent lesion observed (16/45; 35.56%). No statistically significant associations were found between biliary hyperplasia and age or sex. Metal(loid)s' concentrations were higher in animals with biliary hyperplasia (except for As). There was a statistically significant difference for both Cd and Co. For As, Cd and Co, cubs and juveniles animals showed significantly lower concentrations than elder individuals. Only for Pb were significant differences found between females and males. As described in the literature, exposure to metal(loid)s may be a cause of biliary hyperplasia, although further research (including the use of biochemical methods) is needed to support these results. To the authors' knowledge, this is the first report of this association in hedgehogs.

Protective Effect of 3-Benzoyl-7-Hydroxy Coumarin on Lipid Peroxidation and Minerals on Rat Liver Tissues Induced Oxidative Stress with Lead Acetate

Lead is a toxic substance and damages human metabolism. Coumarin-derived substances have many effects such as antioxidant, anticancer, and antibacterial ones. In this study, the effects of 3-benzoyl-7-hydroxy coumarin on rat liver tissues under oxidative stress with lead acetate were investigated. In the study, rats were divided into 4 groups. Control group (K), Coumarin group (KUM), Lead acetate group (P) and Coumarin+Lead acetate group (KUMP) groups were formed. Malondialdehyde (MDA), lead (Pb), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) levels were determined in the liver tissues of the rats. MDA level of P group increased compared to the other groups. A decrease was observed in the KUMP group compared to the P group MDA level. While the Pb and Fe levels of the P group increased compared to the K group, the Pb and Fe levels of the KUMP group decreased compared to the P group. As a result, it is concluded that the 3-benzoyl-7-hydroxy coumarin molecule protects the high lipid peroxidation, lead, and iron metabolism caused by lead acetate in the liver.

Antioxidative, Anti-Inflammatory, Anti-Obesogenic, and Antidiabetic Properties of Tea Polyphenols-The Positive Impact of Regular Tea Consumption as an Element of Prophylaxis and Pharmacotherapy Support in Endometrial Cancer

Endometrial cancer (EC) is second only to cervical carcinoma among the most commonly diagnosed malignant tumours of the female reproductive system. The available literature provides evidence for the involvement of 32 genes in the hereditary incidence of EC. The physiological markers of EC and coexisting diet-dependent maladies include antioxidative system disorders but also progressing inflammation; hence, the main forms of prophylaxis and pharmacotherapy ought to include a diet rich in substances aiding the organism’s response to this type of disorder, with a particular focus on ones suitable for lifelong consumption. Tea polyphenols satisfy those requirements due to their proven antioxidative, anti-inflammatory, anti-obesogenic, and antidiabetic properties. Practitioners ought to consider promoting tea consumption among individuals genetically predisposed for EC, particularly given its low cost, accessibility, confirmed health benefits, and above all, suitability for long-term consumption regardless of the patient’s age. The aim of this paper is to analyse the potential usability of tea as an element of prophylaxis and pharmacotherapy support in EC patients. The analysis is based on information available from worldwide literature published in the last 15 years.

Protective Effects of Green Tea Supplementation against Lead-Induced Neurotoxicity in Mice

The use of natural products as therapeutic agents is rapidly growing recently. In the current study, we investigated the protective effects of green tea supplementation on lead-induced toxicity in mice. Forty albino mice were divided into four groups as follows: A: control group; B: green tea receiving group; C: lead-intoxicated group; and D: lead-intoxicated group supplemented with green tea. At the end of the experiment, the animals were tested for neurobehavioral and biochemical alterations. Green tea was analyzed through Gas Chromatography–Mass Spectrometry (GC/MS) analysis. We found that supplementation with green tea ameliorated the lead-associated increase in body weight and blood glucose. Green tea supplementation also changed the blood picture that was affected due to lead toxicity and ameliorated lead-induced dyslipidemia. The group of mice that were supplemented with green tea has shown positive alterations in locomotory, anxiety, memory, and learning behaviors. The GC/MS analysis revealed many active ingredients among which the two most abundant were caffeine and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester. We concluded that green tea supplementation has several positive effects on the lead-induced neurotoxicity in mice and that these effects may be attributed to its main two active ingredients.

Modulatory efficacy of Punica granatum L. powder ethanol extract (PLEE) on lead acetate-induced hepatic and renal toxicity

Background

Pomegranate powder derived from pomegranate fruit contains phytochemicals chief of which is ellagitannins. Owing to their high antioxidative capabilities we investigated its efficacy against lead acetate induced hepatic and renal toxicity.

Methods

Pomegranate powder (500 g) was procured and soaked in 1 Litre of ethanol for three days, its filtrate was concentrated and freeze dried to form Punica granatum L. ethanol extract (PLEE). Thirty (30) male albino Wistar rats with average weight between 140 ± 20 g were used for this study. They were equally shared into 6 groups with 5 animals each; A: Control; B: Lead acetate only C: Lead acetate + PLEE (1); D: Lead acetate + PLEE (2); E: PLEE (1) and F: PLEE (2). Serum, liver and kidney samples were obtained for biochemical assays. The integrity of liver and kidney tissues were also accessed.

Results

Lead administration resulted in marked elevations in liver transaminases in serum and liver as well as a significant increase in kidney function markers in the serum and kidney (p < 0.05). There was also a significant decline in average body weight, antioxidant markers in the liver and kidney of Wistar rats while there was a significant increase in lipid peroxidation levels in both liver and kidney. However, administration of PLEE at different doses significantly modulated these changes.

Conclusion

Lead acetate administration led to hepatic and renal toxicity as evident by alterations in liver and kidney function markers, antioxidant status and tissue integrity. However, PLEE can combat these toxicities.

Potential role of green tea extract and epigallocatechin gallate in preventing bisphenol A-induced metabolic disorders in rats: Biochemical and molecular evidence

BACKGROUND

Bisphenol A (BPA) is an artificial chemical widely used in the production of polycarbonate plastics and epoxy resins. Accumulating evidence indicates that BPA exposure is associated with metabolic disorders. The beneficial effects of green tea and epigallocatechin gallate (EGCG), major catechin present in green tea, on alleviating BPA-induced metabolic disorders have been shown in various studies.

PURPOSE

Protective effects of green tea extract and EGCG on BPA-induced metabolic disorders and possible underlying mechanisms were investigated.

METHODS

Rats were randomly divided into control, green tea extract (50 and 100 mg/kg, IP), EGCG (20 and 40 mg/kg, IP), BPA (10 mg/kg, gavage), BPA plus green tea extract (25, 50, and 100 mg/kg, IP), BPA plus EGCG (10, 20, and 40 mg/kg, IP), and BPA plus vitamin E (200 IU/kg, IP). After two months, body weight, blood pressure, biochemical blood tests, hepatic malondialdehyde (MDA), and glutathione (GSH) were assessed. By enzyme-linked immunosorbent assay, serum levels of insulin, leptin, adiponectin, TNFα, and IL-6, and by western blotting, hepatic insulin signaling (IRS-1, PI3K, Akt) were measured.

RESULTS

BPA increased body weight, blood pressure, and MDA, decreased GSH, elevated serum levels of low-density lipoprotein cholesterol, total cholesterol, triglyceride, glucose, insulin, leptin, TNFα, IL-6, and liver enzymes including alanine aminotransferase and alkaline phosphatase, and lowered high-density lipoprotein cholesterol and adiponectin levels. In western blot, decreased phosphorylation of IRS-1, PI3K, and Akt was obtained. Administration of green tea extract, EGCG, or vitamin E with BPA reduced the detrimental effects of BPA.

CONCLUSION

These findings indicate that green tea extract and EGCG can be effective in preventing or reducing metabolic disorders induced by BPA linked to their antioxidant and anti-inflammatory activity, regulating the metabolism of lipids, and improving insulin signaling pathways.

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.

Genetic susceptibility of δ-ALAD associated with lead (Pb) intoxication: sources of exposure, preventive measures, and treatment interventions

Delta-aminolevulinic acid dehydratase (δ-ALAD) is involved in the synthesis of haem and exhibits a polymorphic nature. δ-ALAD polymorphism produces two alleles, namely δ-ALAD-1 and δ-ALAD-2, which in turn produce three different phenotypes, namely δ-ALAD1-1, δ-ALAD1-2, and δ-ALAD2-2. δ-ALAD gene is more susceptible to lead (Pb) toxicity than any other genes. Its genotype and phenotype frequencies change with respect to different geographical areas and extent of Pb exposure. The δ-ALAD-2 allele dominancy is linked with high concentration of lead in the body. It has also been thought that the δ-ALAD-2 allele can provoke Pb toxicity by producing a protein that binds more tightly with Pb than δ-ALAD-1 protein. However, few evidences suggest that δ-ALAD-2 may reduce harmful effects by increasing excretion of Pb from the body, thus producing its unavailability towards pathophysiologic alterations. However, the recent evidences have supported that the individuals who are heterozygote for the δ-ALAD-1 allele may be associated with a higher risk of long-term Pb toxicity. In this regard, the individuals who are exposed at occupational levels are among the most frequent study population. The main objective of our study was to explore the gene susceptibility associated with Pb poisoning. Moreover, this study also summarizes various sources of Pb exposure and thereafter outlined multiple strategies to minimize the Pb toxicity in order to save the exposed residential communities.

Protective Effect of Quercetin on Testis Structure and Apoptosis Against Lead Acetate Toxicity: an Stereological Study

Exposure to environmental pollutants tightly impacts on the male fertility. In the present study, we examined the toxic effects of lead acetate (Pb) on testicular structure and the possible effect of quercetin on mitigating these effects. The apoptotic changes in the testes were also studied by the TUNEL assay and changes in apoptosis-related gene (Bax, Bcl-2, and caspase-3) expression. Twenty-one male mice were randomly divided into 3 groups of control, Pb, and lead acetate + quercetin. Testicular weight, both absolute and relative, was higher in Pb-exposed mice in comparison with the control and Pb-quercetin groups. The increase in size of testis was related to the lumen and connective tissue in this group. Lead acetate induced different patterns in testicular cell number; as spermatogonia, spermatocyte, and Sertoli cells number did not affect in lead acetate exposed group, while total number of round spermatids and long spermatids significantly reduced. In addition, Bcl-2 expression was downregulated, and Bax expression was upregulated in Pb-treated group in comparison with the control and Pb + quercetin groups. The TUNEL assay revealed that the number of apoptotic cells in Pb-treated group were increaed significantley in comparison to other groups. In conclusion, Pb administration adversely impacted on the cellular organization and activation of the apoptotic pathways in the testis; on the other hand, quercetin co-administration with lead partially ameliorated these adverse effects.

Lead nitrate and cadmium chloride induced hepatotoxicity and nephrotoxicity: Protective effects of sesamol on biochemical indices and pathological changes

Lead nitrate (LN) and cadmium chloride (CdCl₂ ), regarded as environmental contaminants, are toxic heavy metals. Sesamol is a dietary phytochemical found in sesame oil. We aimed to analyze the hepatotoxic and nephrotoxic effects of LN and CdCl₂ and to evaluate the possible protective effect of sesamol. LN (90 mg/kg bw per day), CdCl₂ (3 mg/kg bw per day), and sesamol (50 mg/kg bw per day) were given to rats via gavage for 28 days. Total protein, albumin, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, total cholesterol, urea, uric acid, creatinine, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, malondialdehyde, acetylcholinesterase, and histopathological changes were investigated in liver and kidney tissues. Lead and cadmium were found to result in decreases in the antioxidant enzymes and acetylcholinesterase activities, increases in malondialdehyde levels, and changes in serum biochemical parameters and various pathological findings. An improvement in all these parameters was observed in the sesamol-treated groups. PRACTICAL APPLICATIONS: Heavy metals are used in many areas of the industry all over the world. Heavy metals which include lead nitrate and cadmium chloride cause cell damage by oxidative stress. Some of the examining parameters for oxidative stress are SOD, GST, MDA, GPx, and CAT. However, some chemicals such as sesamol are well-liked and widely used as antioxidants against xenobiotic toxicity. We also indicate that sesamol has been shown to protective effect against heavy metals caused cell damage.

Investigating the Opposing Effect of Two Different Green Tea Supplements on Oxidative Stress, Mitochondrial Function and Cell Viability in HepG2 Cells

Green tea extract (GTE) improves exercise outcomes and reduces obesity. However, case studies indicate contradictory physiology regarding liver function and toxicity. We studied the effect of two different decaffeinated GTE (dGTE) products, from a non-commercial (dGTE1) and commercial (dGTE2) supplier, on hepatocyte function using the human cell model, HepG2. dGTE1 was protective against hydrogen peroxide (H₂O₂)-induced apoptosis and cell death by attenuating oxidative stress pathways. Conversely, dGTE2 increased cellular and mitochondrial oxidative stress and apoptosis. A bioavailability study with dGTE showed the major catechin in GTE, EGCG, reached 0.263 µg·ml^-1. In vitro, at this concentration, EGCG mimicked the protective effect of dGTE1. GC/MS analysis identified steric acid and higher levels of palmitic acid in dGTE2 versus dGTE1 supplements. We demonstrate the significant biological differences between two GTE supplements which may have potential implications for manufacturers and consumers to be aware of the biological effects of supplementation.

L-theanine: an astounding sui generis amino acid in poultry nutrition

L-theanine (γ-Glutamylethylamide) is a nonprotein water soluble amino acid (AA) mostly found in leaves of Camellia sinensis (green tea). This is a key component of green tea and is considered as the most abundant form of total AAs in green tea (i.e., about 50%). L-theanine is an exclusive taste ingredient of tea producing an attractive flavor and aroma in tea. It has biological effects such as antioxidant, growth promoter, immune booster, anti-stresser, hepatoprotective, antitumor, antiaging, antimicrobial, anti-inflammatory, and antianxiety activities that are worth noticing. It could reduce the oxidative impairment by reducing the synthesis of reactive oxygen species, oxidative parameters, and lipid damage as well as increasing the activity of antioxidant enzymes. The oral ingestion of L-theanine enhanced γδ T-cell proliferation. Therefore, it is being considered an essential compound of green tea that has the ability to improve immune function. The L-theanine can be used as a potential treatment for hepatic injury and immune-related liver diseases via the downregulation of the inflammatory response through the initiation of nitric oxide synthesis and glutathione production which are likely to be critical for the control of hepatic diseases as well as for the improvement of immune function. In addition, it could be used as a best natural feed additive with a potent antistressor by decreasing the levels of corticosterone, dopamine, and noradrenaline. After systematically reviewing the literature, it is noticed that most studies were carried out on mice, pig, human, and butterfly; while dietary supplementation studies of L-theanine in animal and poultry especially among broilers are very limited because of less awareness of this AA. So, the aim of this review is to encourage the veterinarian and poultry researchers to conduct more research at the molecular level about this AA to expose its more beneficial effects and its mechanism of absorption for potential use of this unique green tea AA in poultry nutrition.

Alleviated Actions of Plantago albicans Extract on Lead Acetate-Produced Hepatic Damage in Rats Through Antioxidant and Free Radical Scavenging Capacities

The aim of this study was to explore the possible protective mechanisms and to determine the antioxidant capacity of phenolic compounds extracted from Plantago albicans against lead acetate-induced hepatic injury. High performance liquid chromatography-photo diode array/electrospray ionization-mass spectrometry (HPLC-PDA/ESI-MS) assay was used to identify the P. albicans extract phenolic compounds. Animals received 100 mg of lead acetate/kg of body weight (bw) in the drinking water for a period of 30 days. The other groups of rats were orally administered with silymarin (300 mg/kg bw) or the P. albicans extract at two doses (100 and 300 mg/kg of bw), once daily, by gastric gavage for the same time. The P. albicans exhibited high total phenolic, flavonoid, and anthocyanin contents. The antioxidant in vitro activity demonstrated that the P. albicans exhibits an important effect against deleterious reactive species. The in vivo results showed that P. albicans prevented the lead acetate-induced significant changes on serum and liver lipid levels. In contrast, P. albicans succeeded in improving the biochemical parameters of serum and liver bringing them closer to the normal values of the control group. It also significantly promoted (P < .05) pro-inflammatory cytokines (TNF-α, IL-6, and NF-κB) in the liver of the experimental animals. The evaluated sample with HPLC-PDA/ESI-MS method showed to contain 10 dominant polyphenols, 2 hydroxycinnamic acids (p-coumaric acid and chlorogenic acids), 4 flavones (Apigenin, Luteolin, Cirsiliol, and Luteolin-7-O-rutinoside), and an anthocyanin (cyanidin-3-glucoside). Hence, it can be concluded that P. albicans could be a potent source of health-beneficial phytochemicals providing a novel therapy to protect liver against lead exposure.

Ameliorative effect of curcumin against lead acetate-induced hemato-biochemical alterations, hepatotoxicity, and testicular oxidative damage in rats

Lead, toxic heavy metal of global concern, induces toxicity in various organs via oxidative stress. Thereby, in this study, the protective role of curcumin against lead acetate-induced toxicity was evaluated. Thirty-two male albino rats were allocated equally into four groups and orally administered with corn oil as a vehicle (Cont.), curcumin (CUR) (400 mg/kg bw), lead acetate (LA) (100 mg/kg bw), and lead acetate plus curcumin (LA + CUR). All rats had received their treatments daily for 4 weeks. The results revealed that LA toxicity induced normocytic normochromic anemia with significant leukocytosis and lymphocytosis. Moreover, LA-intoxicated rats showed a marked elevation in the liver enzyme activities, serum cholesterol, and triglyceride levels. In contrast, sero-immunological parameters, total protein, albumin, globulin, and testosterone levels were significantly reduced compared to the control rats. Additionally, LA-induced hepatic and testicular oxidative damage revealed by marked increased in MDA level with prominent reduction in the antioxidant system. The gene expression of the hepatic pro-inflammatory markers and testicular steroidogenic biomarkers including LHR and aromatase were significantly upregulated; meanwhile, the expressions of testicular StAR, CYP17a, 3B-HDS, SR-B1, and P450SCC were significantly downregulated in the LA-intoxicated group. Curcumin treatment could partially improve the hematological, biochemical, and histopathological alterations induced by LA. Also, it was observed that curcumin significantly restored hepatic pro-inflammatory markers and testicular steroidogenic enzymes. In conclusion, curcumin has antioxidant, anti-inflammatory, and immunomodulatory effects and is able to minimize the LA-induced oxidative damage in rats.

Arctium lappa Root Extract Prevents Lead-Induced Liver Injury by Attenuating Oxidative Stress and Inflammation, and Activating Akt/GSK-3β Signaling

Arctium lappa L. (A. lappa) is a popular medicinal plant with promising hepatoprotective activity. This study investigated the protective effect of A. lappa root extract (ALRE) on lead (Pb) hepatotoxicity, pointing to its ability to modulate oxidative stress, inflammation, and protein kinase B/Akt/glycogen synthase kinase (GSK)-3β signaling. Rats received 50 mg/kg lead acetate (Pb(Ac)₂) and 200 mg/kg ALRE or vitamin C (Vit. C) for 7 days, and blood and liver samples were collected. Pb(Ac)₂ provoked hepatotoxicity manifested by elevated serum transaminases and lactate dehydrogenase, and decreased total protein. Histopathological alterations, including distorted lobular hepatic architecture, microsteatotic changes, congestion, and massive necrosis were observed in Pb(II)-induced rats. ALRE ameliorated liver function and prevented all histological alterations. Pb(II) increased hepatic lipid peroxidation (LPO), nitric oxide (NO), caspase-3, and DNA fragmentation, and serum C-reactive protein, tumor necrosis factor-α, and interleukin-1β. Cellular antioxidants, and Akt and GSK-3β phosphorylation levels were decreased in the liver of Pb(II)-induced rats. ALRE ameliorated LPO, NO, caspase-3, DNA fragmentation and inflammatory mediators, and boosted antioxidant defenses in Pb(II)-induced rats. In addition, ALRE activated Akt and inhibited GSK-3β in the liver of Pb(II)-induced rats. In conclusion, ALRE inhibits liver injury in Pb(II)-intoxicated rats by attenuating oxidative injury and inflammation, and activation of Akt/GSK-3β signaling pathway.

Curcumin Ameliorates Lead-Induced Hepatotoxicity by Suppressing Oxidative Stress and Inflammation, and Modulating Akt/GSK-3β Signaling Pathway

Lead (Pb) is a toxic heavy metal pollutant with adverse effects on the liver and other body organs. Curcumin (CUR) is the principal curcuminoid of turmeric and possesses strong antioxidant and anti-inflammatory activities. This study explored the protective effect of CUR on Pb hepatotoxicity with an emphasis on oxidative stress, inflammation and Akt/GSK-3β signaling. Rats received lead acetate and CUR and/or ascorbic acid (AA) for seven days and samples were collected for analyses. Pb(II) induced liver injury manifested by elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH), as well as histopathological alterations, including massive hepatocyte degeneration and increased collagen deposition. Lipid peroxidation, nitric oxide, TNF-α and DNA fragmentation were increased, whereas antioxidant defenses were diminished in the liver of Pb(II)-intoxicated rats. Pb(II) increased hepatic NF-κB and JNK phosphorylation and caspase-3 cleavage, whereas Akt and GSK-3β phosphorylation was decreased. CUR and/or AA ameliorated liver function, prevented tissue injury, and suppressed oxidative stress, DNA damage, NF-κB, JNK and caspase-3. In addition, CUR and/or AA activated Akt and inhibited GSK-3β in Pb(II)-induced rats. In conclusion, CUR prevents Pb(II) hepatotoxicity via attenuation of oxidative injury and inflammation, activation of Akt and inhibition of GSK-3β. However, further studies scrutinizing the exact role of Akt/GSK-3β signaling are recommended.

Natural antidotes and management of metal toxicity

The global burden of heavy metal especially mercury, arsenic, lead, and cadmium toxicities remains a significant public health challenge. Developing nations are particularly at high risk and carry the highest burden of this hazard. Chelation therapy has been the mainstay for treatment of heavy metal poisoning where the chelating agent binds metal ions to form complex ring-like structures called "chelates" to enhance their elimination from the body. Metal chelators have some drawbacks such as redistribution of some heavy metals from other tissues to the brain thereby increasing its neurotoxicity, causing loss of essential metals such as copper and zinc as well as some serious adverse effects, e.g., hepatotoxicity. The use of natural antidotes, which are easily available, affordable, and with little or no side effects compared to the classic metal chelators, is the focus of this review and suggested as cheaper options for developing nations in the treatment of heavy metal poisoning.

Green tea improves rat sperm quality and reduced cadmium chloride damage effect in spermatogenesis cycle

Introduction: Testicular tissue is part of the reproductive system that some mineral compounds such as cadmium chloride (CdCl₂) destroy. Green tea (Camellia sinensis) extract can reduce the tissue damage caused by toxins due to its antioxidant properties. The aim of this study was to evaluate the effect of green tea extract on sperm quality in cadmium chloride toxicity.

Materials and Methods: In the present study, male Wistar rats were allotted randomly into four groups, namely control group (C), CdCl₂ (1.5mg/kg), GT 1.5% (w/v) and in combinationCdCl₂+GT groups. CdCl₂ was injected intraperitoneally (1.5 mg /kg) whereas the green tea extract was administrated orally. At 13, 25 and 49 days after treatment, the rats were euthanized and the reproductive organs (testes, epididymis) were excised and used for sperm analysis and histo-morphometric examinations.

Results: The mean of the diameter of seminiferous tubes, the number of spermatogonia, Sertoli, Leydig cells and thickness of the germinal layer in the testis were significantly increased (P<0.05) in all groups compared to the CdCl₂ group (P<0.05). Sperm motility, sperm count and testosterone were significantly decreased in the CdCl₂ group compared to all groups of treatment (p<0.05). The mean of MDA was significantly increased in the CdCl₂ group compared to other groups (p<0.05).

Conclusion: Green tea has an antioxidant effect that reduces the effects of free oxygen radicals produced from toxins such as cadmium chloride. In addition, it could decrease lipid peroxidation of the cell membrane and ultimately prevent the destruction of tissues in the long run.

Protective effect of tea against lead and cadmium-induced oxidative stress-a review

Exposure to Cd and Pb reduces the activity of antioxidant enzymes, which points to a decrease in the antioxidant potential of the body as a result of supplying factors which enhance cellular oxidation processes. Man is exposed to the effects of toxic metals because they are present in the environment, including in food. Since no effective ways to reduce the concentrations of Cd an Pb in food exist, studies are undertaken to develop methods of reducing their toxic effect on the body through chelating these metals using nutrients (which reduces their absorption by tissues) or increasing the oxidative capacity of the body (which decreases the possibility of inducing oxidative damage to internal organs). Studies performed on laboratory animals have shown that the use of tea infusions fulfil both functions.

Effects of Supplemental Epigallocatechin Gallate in the Diet of Broilers Exposed to Fluoride Intoxication

We evaluated the effects of dietary epigallocatechin gallate (EGCG) on the performance, biochemical parameters, and liver histopathology of fluoride-intoxicated broiler chickens. In total, 160 1-day-old male broiler chicks (Ross PM3 strain) were collected and assigned to four groups (40 animals each), with four replicates. The control group received a basal diet; the F group received 800 mg/kg fluoride; the EGCG group received 400 mg/kg EGCG; and the EGCG+F group received 400 mg/kg EGCG and 800 mg/kg fluoride. The live weight (LW) of F-treated chicks was significantly lower than that of the controls. In the F-treated groups, feed intake (FI) and LW values were lower, but the feed conversion ratio (FCR) was higher than those of the controls. The ratio of heart weight to LW was found to be the highest in the F-treated groups. Alkaline phosphatase (ALP), aspartate aminotransferase (AST), and total oxidant status (TOS) levels in the F-treated groups were significantly higher, whereas the increase in total cholesterol levels was insignificant than those in the control group. In the EGCG+F group, AST, total cholesterol, and TOS levels decreased to a level comparable to those in the control group. Histopathological evaluation revealed that there were mild changes in the portal region in the EGCG+F group; additionally, there was an improvement in liver morphology in the EGCG+F group compared to that in the F group. Thus, EGCG has potent antioxidant and regenerative effects that can ameliorate the detrimental effects of fluoride toxicity on blood parameters and the liver.

Protective Effects of Dietary Supplements Containing Probiotics, Micronutrients, and Plant Extracts Against Lead Toxicity in Mice

Lead (Pb) intoxication is a serious food safety issue, and the development of relevant dietary strategies is an area of ongoing research. In this study, two different dietary supplements were designed and evaluated for their effects against Pb toxicity in mice. Dietary supplement A contained grape seed extract, tea polyphenols and Lactobacillus plantarum CCFM8661, and dietary supplement B contained vitamin C, calcium carbonate, zinc acetate, and L. plantarum CCFM8661. The results showed that both dietary supplements could effectively decrease Pb levels, protect aminolevulinic acid dehydratase, superoxide dismutase and catalase activities and recover glutathione, zinc protoporphyrin and malondialdehyde levels in tissues and blood of mice. A step-through passive avoidance task confirmed that the dietary supplements could recover the learning and memory capacities of Pb-exposed mice. The protective effects of both dietary supplements to alleviate oxidative stress and cognitive impairments were superior to the chelator treatment. Administration of the dietary supplements during Pb exposure offered more significant protection than administration after Pb exposure. Animal safety evaluation also indicated that these dietary supplements barely induced side effects in the mice. This study provides evidence that dietary supplements containing probiotics, micronutrients, and plant extracts can be considered a new dietary strategy against Pb toxicity.

Antagonistic Effect of Laver, Pyropia yezonensis and P. haitanensis, on Subchronic Lead Poisoning in Rats

Lead, one of the most harmful heavy metals, can cause various hazardous effects on living organisms. This study was undertaken to evaluate the antagonistic and protective effects of two economically important laver species, Pyropia yezoensis and P. haitanensis, against subchronic lead poisoning in rats by a 30-day feeding test. Sixty-four healthy Wistar rats were randomly divided into eight groups with eight rats (4♂ + 4♀) per group, among which, one group was served as the control, the others were respectively treated with lead acetate (5 mg/kg b w), and a combination of lead acetate and P. yezoensis or P. haitanensis at different dosages. Weight gain of rats was observed and recorded. Changes in antioxidant indexes, and liver and renal function markers were determined to evaluate the antagonistic effect. Lead content in rats was determined to investigate lead excretion effect of laver. The results showed that exposure to lead caused lead accumulation in kidney and liver, thus leading to significant oxidative damage and impaired liver and renal function compared to the control group. The co-treatment of laver slightly increased body weight compared to the lead-treated group. The co-administration of laver restored liver and renal function of rats by preventing the increment in the activities of alanine transaminase (ALT), alkaline phosphatase (ALP), and aspartate transaminase (AST), and the levels of blood urea nitrogen (BUN) and creatinine (Cr). The increasing of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities, and lowering of the enhanced malondialdehyde (MDA) contents of rats were observed in the laver co-treated groups, which indicated that laver enhanced the antioxidative capacity of rats. The laver also enhanced lead content in feces and reduced it in liver and kidney. The results indicated that P. yezoensis and P. haitanensis could maintain or promote the normal physiological and biochemical function of lead-induced subchronic poisoning of rats, probably owing to their enhancements of antioxidant capacity and lead excretion.

Dietary compounds as modulators of metals and metalloids toxicity

A large part of the population is exposed to metals and metalloids through the diet. Most of the in vivo studies on its toxicokinetics and toxicity are conducted by means of exposure through drinking water or by intragastric or intraperitoneal administration of aqueous standards, and therefore they do not consider the effect of the food matrix on the exposure. Numerous studies show that some components of the diet can modulate the toxicity of these food contaminants, reducing their effect on a systemic level. Part of this protective role may be due to a reduction of intestinal absorption and subsequent tissue accumulation of the toxic element, although it may also be a consequence of their ability to counteract the toxicity directly by their antioxidant and/or anti-inflammatory activity, among other factors. The present review provides a compilation of existing information about the effect that certain components of the diet have on the toxicokinetics and toxicity of the metals and metalloids of greatest toxicological importance that are present in food (arsenic, cadmium, lead, and mercury), and of their most toxic chemical species.

Detoxification effects of phytonutrients against environmental toxicants and sharing of clinical experience on practical applications

According to the Food and Health Bureau and Trade and Industry Department of the Hong Kong Government, 90 % of the total food supply in Hong Kong was imported from the Mainland China. In addition, the hidden or illegal use of prohibited pesticides, food adulteration (e.g., using industrial salt in food processing, using gutter oil as cooking oil), and pollutions were periodically reported by the media. Excessive exposure to toxic heavy metals or persistent organic pollutants (POPs) from diet or environmental is inevitable amid industrialization and pollution. Understanding of the detoxification ability among nutrients in plant-based food (i.e., phytonutrients in green tea, onion, garlic, coriander, and turmeric) offers therapeutic and preventive effects against the poisoning effects due to these pollutants. Oxidative stress and pro-inflammatory actions are the common mechanisms for heavy metals or POPs toxicities, while phytonutrients counteracts these cellular insults by anti-oxidation, upregulation of anti-inflammatory pathways, and chelation.

The Potency of Red Seaweed (Eucheuma cottonii) Extracts as Hepatoprotector on Lead Acetate-induced Hepatotoxicity in Mice

BACKGROUND

Lead is one of the most toxic metals, producing severe organ damage in animals and humans. Oxidative stress is reported to play an important role in lead acetate-induced liver injury.

AIM

This study was carried out to investigate the role of ethanol extract of Eucheuma cottonii in protecting against lead acetate-induced hepatotoxicity in male mice.

MATERIALS AND METHODS

The sample used fifty male mice which were divided into five groups: negative control (mice were given daily with Aquadest); positive control (mice were given daily with lead acetate 20 mg/kg body weight (BW) orally once in a day for 21 days); and the treatment group (mice were given E. cottonii extracts 200 mg, 400 mg, and 800 mg/kg BW orally once in a day for 25 days, and on the 4^th day, were given lead acetate 20 mg/kg BW 1 h after E. cottonii extract administration for 21 days). On day 25, the levels of serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT), alkaline phosphatase (ALP), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured. The data of SGOT, SGPT, ALP, MDA, SOD, and GPx were analyzed with one-way ANOVA, followed by least significant difference test.

RESULTS

The results showed that oral administration of lead acetate 20 mg/kg BW for 21 days resulted in a significant increase in SGOT, SGPT, ALP, and MDA levels. Moreover, there was a significant decrease in SOD and GPx levels. Treatment with E. cottonii extracts of 800 mg/kg BW but not with 200 mg/kg BW and 400 mg/kg BW significantly (P < 0.05) decreased the elevated SGPT, SGOT, ALP, and MDA levels as compared to positive control group. Treatment with E. cottonii extracts of 800 mg/kg BW also showed a significant increase in SOD and GPx levels as compared to positive control group. Treating mice with lead acetate showed different histopathological changes such as loss of the normal structure of hepatic cells, blood congestion, and fatty degeneration whereas animals treated with lead acetate and E. cottonii extracts showed an improvement in these changes and the tissue appeared with normal structures.

CONCLUSION

It can be concluded that E. cottonii extracts could be a potent natural product and can provide a promising hepatoprotective effect against lead acetate-induced hepatotoxicity in mice.

SUMMARY

In summary, Oxidative stress reported to play an important role in lead acetate induced liver injury. The lead acetate treatment significantly increased the SGOT, SGPT, ALP, MDA, and decreased the antioxidant enzymes (SOD and GPx) in liver. The inhibition of antioxidant enzymes will increase free radicals in liver tissues and might induce liver injury in mice. The presence of ethanol extract of Eucheuma cottonii with lead acetate showed protective effects as attenuating lead acetate against its liver toxicity, and this may be due to the activity of ethanol extract of Eucheuma cottonii as antioxidant. The antioxidant enzymes (SOD and GPx) were increased, and MDA, SGOT, SGPT, ALP were decreased after ethanol extract of Eucheuma cottonii administration. The enzymatic activities (SOD and GPx) and MDA in mice can be used as biomarkers of heavy metal toxicity such as lead acetate. Histopathological view of liver sections in the lead acetate treated group showed the liver damage, as compared to the negative control group. However, administration of ethanol extract of Eucheuma cottonii significantly improved the histopathological in liver of lead acetate-treated mice. From the results of this study we concluded that the ethanol extract of Eucheuma cottonii could be a potent natural product provide a promising protective effect against lead acetate induced liver toxicity in mice. Abbreviations Used: SGOT: Serum Glutamic Oxaloacetic Transaminase, SGPT: Serum Glutamic Pyruvate Transaminase, ALP: Alkaline Phosphatase, MDA: Malondialdehyde, SOD: Superoxide Dismutase, GPx: Glutathione Peroxidase.

Nephrotoxic effects of lead nitrate exposure in diabetic and nondiabetic rats: Involvement of oxidative stress and the protective role of sodium selenite

Heavy metals are known to be toxic to organisms. The present study was undertaken to evaluate the protective effect of sodium selenite against lead nitrate (LN)-induced nephrotoxicity in diabetic and nondiabetic rats. Animals were divided into eight groups where the first was served as a control, whereas the remaining groups were treated with sodium selenite (1 mg/kg b.w.), LN (22.5 mg/kg b.w.) and a combination of LN and sodium selenite and diabetic forms of these groups. Changes in antioxidant enzyme activities, malondialdehide levels, serum urea, uric acid, creatinine levels, body, and kidney weights and histopathological changes were determined after 28 days. LN caused severe histopathological changes, increment in urea, uric acid, creatinine, and MDA levels, also decreasing in antioxidant enzyme activities, body, and kidney weights. In sodium selenite + LN group, we observed the protective effect of sodium selenite on examining parameters. Also diabetes caused alterations on these parameters compared with nondiabetic animals. We found that sodium selenite did not show protective effect on diabetes caused damages. As a result, LN caused nephrotoxicity and sodium selenite alleviated this toxicity but sodium selenite did not protect kidneys against diabetes mediated toxicity. Also, LN caused more harmfull effects in diabetic groups compared with nondiabetic groups. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1229-1240, 2016.

Correlation of In Vivo and In Vitro Assay Results for Assessment of Free Radical Scavenging Activity of Green Tea Nutraceuticals

Green tea (GT)-derived catechins; epigallocatechin gallate (EGCG) in particular are commonly used nutraceuticals for their free-radical scavenging activity (FRSA). The influence of photodegradation on the protective power of GT nutracenticals against oxidative stress was thoroughly explored. Photodegradation of GT extracts was carried out and monitored using orthogonal stability-indicating testing protocol; in vitro and in vivo assays. Total polyphenol content (TPC) and FRSA were determined spectrophotometrically while EGCG was selectively monitored using SPE-HPLC. In vivo assessment of photodegraded samples was investigated via measuring a number of biomarkers for hepatic oxidative stress and apoptosis (caspase-3, inducible nitric oxide synthase, nitric oxide, mitogen-activated protein kinase, glutathione, thiobarbituric acid reactive substances, nuclear factor kappa beta, and nuclear factor erythroid 2-related factor) as well as liver damage (alanine transaminase and aspartate transaminase) in serum of rats previously subjected to oxidative stress. Results showed complete degradation of EGCG in photodegraded green tea samples with no correlation with either TPC or FRSA. On the other hand, in vivo assay results revealed not only loss of activity but formation of harmful pro-oxidants. Photostability was found crucial for the protective effect of GT extract against lead acetate insult. Results confirmed that careful design of quality control protocols requires correlation of chemical assays to bioassays to verify efficacy, stability, and most importantly safety of nutraceuticals.

Effects of Naringenin on Oxidative Stress and Histopathological Changes in the Liver of Lead Acetate Administered Rats

Lead has several adverse effects on the body due to one of the environmental pollutants. We aimed to determine the effects of naringenin on the oxidative stress and the hepatic damage against lead acetate treatment in the liver of male rats. Naringenin was administered by orogastric gavage (50 mg/kg) and lead acetate was given as daily 500 parts per million in drinking water for 4 weeks. Lead and antioxidant activities were measured, and histopathological evaluation was performed in the liver. Lead concentrations, malondialdehyde, and antioxidant activity were restored by the naringenin. The grade of necrosis, hydropic degeneration, and hepatic cord disorganization was decreased by the naringenin. However, there were no differences in the degree of sinusoidal congestion, hepatic steatosis, and capsular fibrosis between lead acetate and naringenin + lead acetate groups. We can suggest that naringenin has antioxidant and chelating effects in the liver. Nevertheless, this effect is not enough against the lead acetate induced hepatic injury.

Antioxidant protection of gallic acid against toxicity induced by Pb in blood, liver and kidney of rats

The effect of the antioxidant gallic acid (GA) on Pb toxicity in blood, liver and kidney was investigated in the present study. Rats Wistar received Pb nitrate (50 mg/Kg/day, i.p., 5 days) followed by GA (13.5 mg/Kg, p.o., 3 days) or a chelating agent (EDTA, 55 mg/Kg, i.p.). As result, Pb decreased body weight, hematocrit and blood δ-aminolevulinic acid dehydratase (ALA-D) activity. In addition, high Pb levels were observed in blood and tissues, together with increased (1) lipid peroxidation in erythrocytes, plasma and tissues, (2) protein oxidation in tissues and (3) plasma aspartate transaminase (AST) levels. These changes were accompanied by decreasing in antioxidant defenses, like superoxide dismutase (SOD) activity in tissues and catalase (CAT) activity and reduced glutathione (GSH) in liver. GA was able to reverse Pb-induced decrease in body weight and ALA-D activity, as well as Pb-induced oxidative damages and most antioxidant alterations, however it did not decrease Pb bioaccumulation herein as EDTA did. Furthermore, EDTA did not show antioxidant protection in Pb-treated animals as GA did. In conclusion, GA decreased Pb-induced oxidative damages not by decreasing Pb bioaccumulation, but by improving antioxidant defenses, thus GA may be promising in the treatment of Pb intoxications.

Molecular and Histopathological Study on the Ameliorative Effects of Curcumin Against Lead Acetate-Induced Hepatotoxicity and Nephrototoxicity in Wistar Rats

Lead (Pb(2+)) toxicity is the most common form of heavy metal intoxication in humans and animals. Therefore, the current study was conducted to evaluate the potential ameliorative effects of curcumin on lead acetate (LA)-induced deleterious effects in the liver and kidney. Forty male Wistar rats were divided into four equal groups; first group was used as a control and given both corn oil orally and vehicle of lead acetate intraperitoneally (i.p). Groups from 2-4 were treated with lead acetate (LA; 50 mg/kg BW i.p), curcumin (200 mg/kg BW orally), and curcumin plus lead acetate, respectively. Curcumin was administered 3 weeks before LA injection for 7 days. Pb(2+)-intoxicated rats have higher Pb(2+) levels compared to other treated groups. Results revealed that lead acetate significantly increased the serum levels of hepatic transaminases (GPT and GOT), urea and creatinine, while albumin was significantly decreased. In parallel, serum IgG, IgM, and IgA were significantly decreased in LA-injected rats. LA groups showed decrease in messenger RNA (mRNA) expression of catalase, SOD, GST, GPx, and alpha-1 acid glycoprotein (AGP), while the gene expression of desmin, vimentin, transforming growth factor-β1 (TGF-β1), monocyte chemoattractant protein-1 (MCP-1), and alpha-2 macroglobulin (α-2M) was increased. Prior and coadministration of curcumin with LA for 7 days significantly improved the ameliorated changes in liver and kidney, immunoglobulins, and mRNA expression. Moreover, curcumin ameliorated LA-induced congestion of hepatic and renal blood vessels and decreased fibrous tissue proliferation and necrosis of hepatocytes. In the kidney, LA-induced degeneration in tubular epithelium and intraluminal hyaline casts and prior curcumin administration restored normal renal structure with mild congestion of renal blood vessels. The results clarify the potential of curcumin to counteract the immunosuppressive alteration in gene expression as well as hepatic and renal damage occurred after Pb(2+) intoxication.

Protective effects of sodium selenite on lead nitrate-induced hepatotoxicity in diabetic and non-diabetic rats

In the present study, the effect of sodium selenite on lead induced toxicity was studied in Wistar rats. Sodium selenite and lead nitrate were administered orally for 28 days to streptozotocin induced diabetic and non-diabetic rats. Eight groups of rats were used in the study: control, sodium selenite, lead nitrate, lead nitrate+sodium selenite, streptozotocin-induced diabetic-control, diabetic-sodium selenite, diabetic-lead nitrate, diabetic-lead nitrate+sodium selenite groups. Serum biochemical parameters, lipid peroxidation, antioxidant enzymes and histopathological changes in liver tissues were investigated in all groups. There were statistically significant changes in liver function tests, antioxidant enzyme activities and lipid peroxidation levels in lead nitrate and sodium selenite+lead nitrate treated groups, also in diabetic and non-diabetic groups. Furthermore, histopathological alterations were demonstrated in same groups. In the present study we found that sodium selenite treatment did not show completely protective effect on diabetes mellitus caused damages, but diabetic rats are more susceptible to lead toxicity than non-diabetic rats.

Effects of lead nitrate and sodium selenite on DNA damage and oxidative stress in diabetic and non-diabetic rat erythrocytes and leucocytes

The adverse effects of lead nitrate (LN) and the preventive role of sodium selenite were investigated in diabetic and non-diabetic rat blood by measuring trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), malondialdehyde (MDA) levels and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) also by evaluating DNA damage with comet assay. LN increased the levels of MDA, tail DNA%, mean tail length and tail moment, decreased the enzymes activities, FRAP and TEAC values. In sodium selenite+LN group, we observed the protective effect of sodium selenite on examining parameters. Diabetes caused alterations on these parameters, too. We found that sodium selenite did not protect against diabetes caused damages. As a result, LN caused toxic effects on blood cells and sodium selenite alleviated this toxicity but it did not show preventive effect against diabetes. Also, LN caused more harmfull effects in diabetic groups than non-diabetic groups.

Dietary strategies for the treatment of cadmium and lead toxicity

Cadmium (Cd) and lead (Pb) are toxic heavy metals that cause adverse health effects in humans and animals. Chelation therapy, the conventional treatment for heavy metal toxicity, is reported to have a number of safety and efficacy issues. Recent studies have shown that dietary supplements play important roles in protecting against Cd and Pb toxicity. This paper reviews the evidence for protective effects of essential metals, vitamins, edible plants, phytochemicals, probiotics and other dietary supplements against Cd and Pb toxicity and describes the proposed possible mechanisms. Based on these findings, dietary strategies are recommended for people at risk of Cd and Pb exposure. The application of these strategies is advantageous for both the prevention and alleviation of Cd and Pb toxicity, as such supplements can be added easily and affordably to the daily diet and are expected to have very few side effects compared to the chelation therapy.

Silibinin mitigates zidovudine-induced hepatocellular degenerative changes, oxidative stress and hyperlipidaemia in rats

Prolonged zidovudine (AZT) treatment in HIV-infected and AIDS patients is shown to induce liver toxicity leading to complications. Therapeutic regimen that could encounter this adverse effect is unavailable and management of toxicity is often symptomatic or is limited to withdrawal of therapy. In the present investigation, we evaluated the alleviating properties of silibinin (SBN), a flavanolignan obtained from Silybum marianum against subacute AZT-induced hepatotoxicity and oxidative stress in rats. AZT treatment (50 mg/kg body weight (b.w.) periorally (p.o.), daily for 45 days) caused highly significant increases in alanine transaminase, alkaline phosphatase, argininosuccinic acid lyase and bilirubin in serum. Oxidative stress is shown by a highly significant increase in lipid peroxidase and total carbonyl content and decrease in catalase and protein thiols in the liver tissue. Hyperlipidaemia is indicated by highly significant increase in total lipids and free fatty acid in serum. Evaluation of liver by haematoxylin and eosin staining shows parenchymal cell enlargement, inflammatory changes and increase in sinusoidal spaces. Simultaneous treatment of SBN (100 mg/kg b.w. p.o., daily for 45 days) significantly protected the liver against hepatotoxicity, oxidative stress and hyperlipidaemia induced by AZT, and this alleviating property is attributed to hepatoprotective, membrane-stabilizing, antioxidant and free radical scavenging properties of SBN.

Protective role of omega-3 polyunsaturated fatty acid against lead acetate-induced toxicity in liver and kidney of female rats

The present study was conducted to investigate the protective role of Omega-3 polyunsaturated fatty acids against lead acetate-induced toxicity in liver and kidney of female rats. Animals were divided into four equal groups; group 1 served as control while groups 2 and 3 were treated orally with Omega-3 fatty acids at doses of 125 and 260 mg/kg body weight, respectively, for 10 days. These groups were also injected with lead acetate (25 mg/kg body weight) during the last 5 days. Group 4 was treated only with lead acetate for 5 days and served as positive control group. Lead acetate increased oxidative stress through an elevation in MDA associated with depletion in antioxidant enzymes activities in the tissues. Moreover, the elevation of serum enzymes activities (ALT, AST, ALP, and LDH) and the levels of urea and creatinine were estimated but total proteins were decreased. Also, lead acetate-treatment induced hyperlipidemia via increasing of lipid profiles associated with decline in HDL-c level. Significant changes of Hb, PCV, RBCs, PLT, and WBCs in group 4 were recorded. The biochemical alterations of lead acetate were confirmed by histopathological changes and DNA damage. The administration of Omega-3 provided significant protection against lead acetate toxicity.

Hydroalcoholic seed extract of Coriandrum sativum (Coriander) alleviates lead-induced oxidative stress in different regions of rat brain

Lead exposure is known to cause apoptotic neurodegeneration and neurobehavioral abnormalities in developing and adult brain by impairing cognition and memory. Coriandrum sativum is an herb belonging to Umbelliferae and is reported to have a protective effect against lead toxicity. In the present investigation, an attempt has been made to evaluate the protective activity of the hydroalcoholic extract of C. sativum seed against lead-induced oxidative stress. Male Wistar strain rats (100-120 g) were divided into four groups: control group: 1,000 mg/L of sodium acetate; exposed group: 1,000 mg/L lead acetate for 4 weeks; C. sativum treated 1 (CST1) group: 250 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure; C. sativum treated 2 (CST2) group: 500 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure. After the exposure and treatment periods, rats were sacrificed by cervical dislocation, and the whole brain was immediately isolated and separated into four regions: cerebellum, hippocampus, frontal cortex, and brain stem along with the control group. After sacrifice, blood was immediately collected into heparinized vials and stored at 4 °C. In all the tissues, reactive oxygen species (ROS), lipid peroxidation products (LPP), and total protein carbonyl content (TPCC) were estimated following standard protocols. An indicator enzyme for lead toxicity namely delta-amino levulinic acid dehydratase (δ-ALAD) activity was determined in the blood. A significant (p<0.05) increase in ROS, LPP, and TPCC levels was observed in exposed rat brain regions, while δ-ALAD showed a decrease indicating lead-induced oxidative stress. Treatment with the hydroalcoholic seed extract of C. sativum resulted in a tissue-specific amelioration of oxidative stress produced by lead.

Protective effect of curcumin against heavy metals-induced liver damage

Occupational or environmental exposures to heavy metals produce several adverse health effects. The common mechanism determining their toxicity and carcinogenicity is the generation of oxidative stress that leads to hepatic damage. In addition, oxidative stress induced by metal exposure leads to the activation of the nuclear factor (erythroid-derived 2)-like 2/Kelch-like ECH-associated protein 1/antioxidant response elements (Nrf2/Keap1/ARE) pathway. Since antioxidant and chelating agents are generally used for the treatment of heavy metals poisoning, this review is focused on the protective role of curcumin against liver injury induced by heavy metals. Curcumin has shown, in clinical and preclinical studies, numerous biological activities including therapeutic efficacy against various human diseases and anti-hepatotoxic effects against environmental or occupational toxins. Curcumin reduces the hepatotoxicity induced by arsenic, cadmium, chromium, copper, lead and mercury, prevents histological injury, lipid peroxidation and glutathione (GSH) depletion, maintains the liver antioxidant enzyme status and protects against mitochondrial dysfunction. The preventive effect of curcumin on the noxious effects induced by heavy metals has been attributed to its scavenging and chelating properties, and/or to the ability to induce the Nrf2/Keap1/ARE pathway. However, additional research is needed in order to propose curcumin as a potential protective agent against liver damage induced by heavy metals.

Antioxidative effects of hesperetin against lead acetate-induced oxidative stress in rats

Objectives:

Oxidative stress with subsequent lipid peroxidation (LP) has been suggested as a mechanism for lead-induced toxicity. The current study was carried out to evaluate antioxidant activity of hesperetin against lead acetate-induced oxidative stress.

Materials and Methods:

The male rats were treated with hesperetin in combination with lead acetate (500 mg/L).

Results:

The results indicated that hesperetin alone did not induce any significant changes in the biochemistry of serum, liver, and kidney tissues. On the other hand, lead-induced oxidative stress as indicated by significant changes in serum biochemical parameters, including increased lipid peroxide and decreased reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) levels in liver and kidney tissues. Hesperetin succeeded in improving these biochemical parameters towards the normal values of control.

Conclusions:

It suggests that hesperetin shows antioxidant activity and plays a protective role against lead-induced oxidative damage in liver and kidney of rats.

The administration of N-acetylcysteine reduces oxidative stress and regulates glutathione metabolism in the blood cells of workers exposed to lead

CONTEXT AND OBJECTIVE

The aim of the study was to investigate whether treatment with N-acetylcysteine (NAC) is able to restore erythrocyte glutathione (GSH) content in workers exposed to lead. Additionally, we measured the leukocyte and erythrocyte activities of GSH-related enzymes, such as glutathione reductase (GR), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PD), and estimated the influence of NAC administration on oxidative stress intensity, which was measured as the lipofuscin (LPS) level in erythrocytes.

METHODS

The exposed population consisted of 171 healthy males randomly divided into four groups. Workers in the first group (n = 49) were not administered any antioxidants, drugs, vitamins, or dietary supplements, while workers in the remaining groups were treated with NAC at three doses for 12 weeks (1 × 200 mg per day, 2 × 200 mg per day, and 2 × 400 mg per day). All workers continued to work during the study. The blood of all examined workers was drawn two times: at the beginning of the study and after 12 weeks of treatment.

RESULTS AND CONCLUSION

Blood lead levels decreased significantly in all groups receiving NAC compared to those in baseline. Erythrocyte GSH concentrations were significantly elevated in workers receiving 400 and 800 mg of NAC compared to those in baseline by 5% and 6%, respectively. Erythrocyte G6PD activity was significantly elevated in workers receiving 200, 400, and 800 mg of NAC compared to those in baseline by 24%, 14%, and 14%, respectively. By contrast, there were no significant differences in leukocyte G6PD or leukocyte and erythrocyte glutathione reductase (GR) activities before and after treatment. Leukocyte GST activities decreased significantly after treatment in workers receiving 200 mg of NAC by 34%, while LPS levels decreased significantly in workers receiving 200, 400, and 800 mg of NAC compared to those in baseline by 5%, 15%, and 13%, respectively. In conclusion, NAC decreases oxidative stress in workers exposed to lead via stimulating GSH synthesis.