Carbofuran-induced toxicity in rats: protective role of vitamin C

Carbofuran pesticide toxicity to the eye

Pesticide exposure to eyes is a major source of ocular morbidities in adults and children all over the world. Carbofuran (CF), N-methyl carbamate, pesticide is most widely used as an insecticide, nematicide, and acaricide in agriculture, forestry, and gardening. Contact or ingestion of carbofuran causes high morbidity and mortality in humans and pets. Pesticides are absorbed in the eye faster than other organs of the body and damage ocular tissues very quickly. Carbofuran exposure to eye causes blurred vision, pain, loss of coordination, anti-cholinesterase activities, weakness, sweating, nausea and vomiting, abdominal pain, endocrine, reproductive, and cytotoxic effects in humans depending on amount and duration of exposure. Pesticide exposure to eye injures cornea, conjunctiva, lens, retina, and optic nerve and leads to abnormal ocular movement and vision impairment. Additionally, anticholinesterase pesticides like carbofuran are known to cause salivation, lacrimation, urination, and defecation (SLUD). Carbofuran and its two major metabolites (3-hydroxycarbofuran and 3-ketocarbofuran) are reversible inhibitors of acetylcholinesterase (AChE) which regulates acetylcholine (ACh), a neurohumoral chemical that plays an important role in corneal wound healing. The corneal epithelium contains high levels of ACh whose accumulation by AChE inhibition after CF exposure overstimulates muscarinic ACh receptors (mAChRs) and nicotinic ACh receptors (nAChRs). Hyper stimulation of mAChRs in the eye causes miosis (excessive constriction of the pupil), dacryorrhea (excessive flow of tears), or chromodacryorrhea (red tears). Recent studies reported alteration of autophagy mechanism in human cornea in vitro and ex vivo post carbofuran exposure. This review describes carbofuran toxicity to the eye with special emphasis on corneal morbidities and blindness.

Thiram exposure in environment: A critical review on cytotoxicity

Thiram is used in large quantities in agriculture and may contaminate the environment by improper handling or storage in chemical plants and warehouses. A review of the literature has shown that thiram can affect different organs in animals and its toxic mechanisms can be elucidated in more detail at molecular level. We have summarized several impacts of thiram on animals: the effects of the perspectives of oxidative stress, mitochondrial damage, autophagy, apoptosis, and the IHH/PTHrP pathway on regulating abnormal skeletal development in particular tibial dyschondroplasia and kyphosis; angiogenesis inhibition was investigated from the perspective of angiogenesis factor inhibition, PI3K/AKT signaling pathway and CD147; the inhibition effect of thiram on fibroblasts and erythrocytes via the perspective of oxidative stress, mitochondrial damage and inhibition of growth factors in animal skin fibroblasts and erythrocytes; studied fertilized egg size, reduced fertility, neurodegeneration, and immune damage from the perspectives of CYP51 inhibition and dopamine-b-hydroxylase inhibition in the reproductive system, vitamin D deficiency in the nervous system, and inflammatory damage in the immune system; embryonic dysplasia in terms of thyroid hormone repression in animal embryonic development and repression of the SOX9a transcription factor. The elucidation of the mechanisms of toxicity of thiram on various organs of animals at molecular level will enable a more detailed understanding of the mechanisms of toxicity of thiram in animals and will facilitate the exploration of the treatment of thiram poisoning at molecular level.

A Common Feature of Pesticides: Oxidative Stress-The Role of Oxidative Stress in Pesticide-Induced Toxicity

Pesticides are important chemicals or biological agents that deter or kill pests. The use of pesticides has continued to increase as it is still considered the most effective method to reduce pests and increase crop growth. However, pesticides have other consequences, including potential toxicity to humans and wildlife. Pesticides have been associated with increased risk of cardiovascular disease, cancer, and birth defects. Labels on pesticides also suggest limiting exposure to these hazardous chemicals. Based on experimental evidence, various types of pesticides all seem to have a common effect, the induction of oxidative stress in different cell types and animal models. Pesticide-induced oxidative stress is caused by both reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are associated with several diseases including cancer, inflammation, and cardiovascular and neurodegenerative diseases. ROS and RNS can activate at least five independent signaling pathways including mitochondrial-induced apoptosis. Limited in vitro studies also suggest that exogenous antioxidants can reduce or prevent the deleterious effects of pesticides.

Investigation of the Protective Role of Selenium in the Changes Caused by Chlorpyrifos in Trace Elements, Biochemical and Hematological Parameters in Rats

Organophosphate compounds are the most widely employed insecticides in countries with high agriculture activity. On average, organophosphates cause 3 million people to poison and 200 000 deaths per year due to food chain or occupational, accidental, or suicidal exposure. Our study aimed to research selenium's protective role against the toxic action of CPF, one of the most commonly used organophosphates, with an experimental model formed with rats. A total of 56 male SD rats were distributed into seven groups as follows: control (tap water), sham (corn oil), group I (5.4 mg/kg CPF), group II (13.5 mg/kg CPF), group III (3 mg/kg Se), group IV (5.4 mg/kg CPF+Se), and group V (13.5 mg/kg CPF+Se). Following 6 weeks of oral exposure, there were significant changes in AChE activity, biochemical and hematological parameters, and trace element levels in CPF-treated rats. In the high-dose CPF group, RBC values, Hb, and Hct decreased, and values of WBC, AST, ALT, ALP increased (p < 0.001) significantly compared to control, sham, and Se groups. While there was no significant change in zinc level, the copper and selenium levels were significantly higher in group IV than in control (p < 0.001) and sham (p < 0.05, p < 0.01, respectively) groups. Moreover, max. O.R.L. was found statistically more elevated in the high-dose CPF group compared to control, sham, and Se groups (p < 0.05, p < 0.05, and p < 0.01, respectively). All results indicated that Se is an antioxidant that reduces the toxic effects caused by CPF. Employing combinations of chlorpyrifos and selenium appeared greatly in restoring the harmful effects of CPF exposure.

Cardiotoxicity of some pesticides and their amelioration

Pesticides are used to control pests that harm plants, animals, and humans. Their application results in the contamination of the food and water systems. Pesticides may cause harm to the human body via occupational exposure or the ingestion of contaminated food and water. Once a pesticide enters the human body, it may create health consequences such as cardiotoxicity. There is not enough information about pesticides that cause cardiotoxicity in the literature. Currently, there are few reports that summarized the cardiotoxicity due to some pesticide groups. This necessitates reviewing the current literature regarding pesticides and cardiotoxicity and to summarize them in a concrete review. The objectives of this review article were to summarize the advances in research related to pesticides and cardiotoxicity, to classify pesticides into certain groups according to cardiotoxicity, to discuss the possible mechanisms of cardiotoxicity, and to present the agents that ameliorate cardiotoxicity. Approximately 60 pesticides were involved in cardiotoxicity: 30, 13, and 17 were insecticides, herbicides, and fungicides, respectively. The interesting outcome of this study is that 30 and 13 pesticides from toxicity classes II and III, respectively, are involved in cardiotoxicity. The use of standard antidotes for pesticide poisoning shows health consequences among users. Alternative safe medical management is the use of cardiotoxicity-ameliorating agents. This review identifies 24 ameliorating agents that were successfully used to manage 60 cases. The most effective agents were vitamin C, curcumin, vitamin E, quercetin, selenium, chrysin, and garlic extract. Vitamin C showed ameliorating effects in a wide range of toxicities. The exposure mode to pesticide residues, where 1, 2, 3, and 4 are aerial exposure to pesticide drift, home and/or office exposure, exposure due to drinking contaminated water, and consumption of contaminated food, respectively. General cardiotoxicity is represented by 5, whereas 6, 7, 8 and 9 are electrocardiogram (ECG) of hypotension due to exposure to OP residues, ECG of myocardial infraction due to exposure to OPs, ECG of hypertension due to exposure to OC and/or PY, and normal ECG respectively.

Antioxidant mediated protective effect of Bridelia tomentosa leaf extract against carbofuran induced oxidative hepatic toxicity

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Bridelia tomentosa is a traditional medicinal plant that is used against colitis, traumatic injury, diarrhea, and diabetes.

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Gallic acid, Tannic acid, salicylic acid, and naringin were isolated from the leaf of B. tomentosa for the first time.

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B. tomentosa extract amended serum biochemical markers, MDA levels, and improved the levels of hepatic antioxidant enzymes.

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Phenolic and flavonoid compounds of the B. tomentosa can be used as nutraceuticals for treating oxidative hepatic ailments.

Bridelia tomentosa (B. tomentosa) is a traditional medicinal plant for treating diverse ailments. Hence, we designed our study to scrutinize the protective effect of the methanol extract of B. tomentosa leaf (BTL) against carbofuran-induced oxidative stress-mediated hepato-toxicity in Sprague-Dawley rats for the first time, along with the identification and quantification of phenolic acids and flavonoids by high-performance liquid chromatography (HPLC) and evaluation of antioxidant and antiradical activities of this extract. HPLC analysis confirmed the existence of tannic acid, gallic acid, salicylic acid, and naringin in B. tomentosa leaf extract which showed in-vitro antioxidant potentialities with DPPH, nitric oxide, hydrogen peroxide, and hydroxyl radical scavenging properties. Co-administration of B. tomentosa leaf extract with carbofuran showed dose-dependent significant protective effects of hepatic toxicity on serum markers such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl-transferase, lactate dehydrogenase, total bilirubin, total protein, albumin, globulin, lipid profile, urea, uric acid, and creatinine. Carbofuran intoxication also revealed an upsurge in malondialdehyde (MDA) and a decline in cellular endogenous antioxidant enzyme levels in rats compared with the control group. However, B. tomentosa leaf extract co-treatment increased the levels of hepatic antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, and amended the MDA level. Similarly, histopathological evaluation further assured that BTL could keep the hepatocyte from carbofuran-induced damage. Therefore, all of our findings may conclude that the phenolic acids and flavonoids of B. tomentosa leaf extract are responsible to neutralize the toxic free radical-mediated oxidative hepatic damages.

Carbofuran cytotoxicity, DNA damage, oxidative stress, and cell death in human umbilical vein endothelial cells: Evidence of vascular toxicity

Carbofuran is a broad-spectrum carbamate insecticide, which principally inhibits the acetylcholinesterase (AChE) enzyme in the nervous system. Nonetheless, their selective action is not restricted to a single species and expanded to humans. No studies are available on the toxicological effects of carbofuran in the endothelial cells (ECs), which first confronts the toxicants in blood vessels. Hence, we have exposed the human umbilical vein ECs (HUVECs) with carbofuran for 24 h, which significantly reduced the cell survival to 25.16% and 33.48% at 500 and 1,000 μM analyzed by MTT assay. In the neutral red uptake (NRU) assay, 16.68%, 30.99%, and 58.11% survival decline was found at 250, 500, and 1,000 μM of carbofuran. HUVECs exposed to carbofuran showed significant increase in the intracellular reactive oxygen species (ROS), indicating oxidative stress at low concentrations. In parallel, HUVECs showed hyperpolarization effects in the mitochondrial membrane potential (ΔΨm) upon carbofuran exposure. Carbofuran induced DNA damage in HUVECs measured as 8.80, 11.82, 35.56, and 79.69 Olive tail moment (OTM) in 100-, 250-, 500-, and 1,000-μM exposure groups. Flow cytometric analysis showed apoptotic peak (SubG1) and G2M arrest in the HUVECs exposed to carbofuran. Overall, our novel data confirm that carbofuran is toxic for the EC cells, especially at the higher concentrations, which may affect the vascular functions and possibly angiogenesis. Hence, carbofuran should be applied judiciously, and detailed vascular studies are warranted to gain an in-depth information focusing the transcriptomic and translation changes employing suitable in vivo and in vitro test models.

Carbofuran accelerates the cellular senescence and declines the life span of spns1 mutant zebrafish

Carbofuran is a carbamate pesticide, widely used in agricultural practices to increase crop productivity. In mammals, carbofuran is known to cause several untoward effects, such as apoptosis in the hippocampal neuron, oxidative stress, loss of memory and chromosomal anomalies. Most of these effects are implicated with cellular senescence. Therefore, the present study aimed to determine the effect of carbofuran on cellular senescence and biological ageing. Spinster homolog 1 (Spns1) is a transmembrane transporter, regulates autolysosomal biogenesis and plays a role in cellular senescence and survival. Using senescence‐associated β‐galactosidase staining, we found that carbofuran accelerates the cellular senescence in spns1 mutant zebrafish. The yolk opaqueness, a premature ageing phenotype in zebrafish embryos, was accelerated by carbofuran treatment. In the survival study, carbofuran shortened the life span of spns1 mutant zebrafish. Autophagy is the cellular lysosomal degradation, usually up‐regulated in the senescent cells. To know the impact of carbofuran exposure on autophagy progress, we established a double‐transgenic zebrafish line, harbouring EGFP‐tagged LC3‐II and mCherry‐tagged Lamp1 on spns1 mutant background, whereas we found, carbofuran exposure synergistically accelerates autolysosome formation with insufficient lysosome‐mediated degradation. Our data collectively suggest that carbofuran exposure synergistically accelerates the cellular senescence and affects biological ageing in spns1 defective animals.

Carbofuran toxicity and its microbial degradation in contaminated environments

Carbofuran is one of the most toxic broad-spectrum and systemic N-methyl carbamate pesticide, which is extensively applied as insecticide, nematicide and acaricide for agricultural, domestic and industrial purposes. It is extremely lethal to mammals, birds, fish and wildlife due to its anticholinesterase activity, which inhibits acetyl-cholinesterase and butyrylcholinesterse activity. In humans, carbofuran is associated with endocrine disrupting activity, reproductive disorders, cytotoxic and genotoxic abnormalities. Therefore, cleanup of carbofuran-contaminated environments is of utmost concern and urgently needs an adequate, advanced and effective remedial technology. Microbial technology (bacterial, fugal and algal species) is a very potent, pragmatic and ecofriendly approach for the removal of carbofuran. Microbial enzymes and their catabolic genes exhibit an exceptional potential for bioremediation strategies. To understand the specific mechanism of carbofuran degradation and involvement of carbofuran hydrolase enzymes and genes, highly efficient genomic approaches are required to provide reliable information and unfold metabolic pathways. This review briefly discusses the carbofuran toxicity and its toxicological impact into the environment, in-depth understanding of carbofuran degradation mechanism with microbial strains, metabolic pathways, molecular mechanisms and genetic basis involved in degradation.

Predominant role of antioxidants in ameliorating the oxidative stress induced by pesticides

Oxidative stress has been reported as one of the adverse effects caused due to pesticides, which is the main mechanism of the toxicity in humans and animals and is a useful parameter in monitoring studies. It involves an imbalance in the equilibrium state of ROS and antioxidant defenses leading to alterations in various antioxidant enzyme levels and lipid peroxidation. The objective of the current paper is to present a review of the potential role and protective mechanism action of the antioxidant micronutrient supplementation to ameliorate the oxidative stress induced by pesticides. Studies in animal models and human were retrieved through the relevant search of the literature and categorized. Various animal studies were categorized according to the type of supplementation. Animal studies provide evidence to conclude the potential protective role of antioxidants in ameliorating the adverse effects of pesticides. Similar studies in humans are meager suggesting for further comprehensive research.

Sub-chronic treatment with high doses of ascorbic acid reduces lead levels in hen eggs intentionally exposed to a concentrated source of lead: a pilot study

Background

Hen eggs contaminated with lead can be harmful to the health of children and adults. The objective of this pilot study was to investigate if sub-chronic treatment with ascorbic acid can reduce lead levels in the different parts of hen eggs after intentionally exposing the laying hens to a concentrated source of lead.

Methods

Clinically normal mixed-breed egg laying hens (n = 18) were used in this pilot study. Hens were exposed to a concentrated source of lead (200 mg/kg_{body weight}/day lead acetate) for 1 week. Subsequently, egg laying hens were either treated with sub-chronic doses of ascorbic acid (500 mg/kg_{body weight}/day) or left untreated for 4 weeks. Lead levels were assessed in egg-shell, egg-albumen, and egg-yolk samples using a graphite furnace atomic absorption spectrophotometer.

Results

Lead levels increased significantly (p-value < 0.01) from baseline in egg-yolk, egg-albumen, and egg-shell samples following 1 week exposure to lead acetate. Sub-chronic treatment of egg laying hens with high doses of ascorbic acid could bring statistically significant reduction (p-value < 0.01) in lead levels in egg-yolk, egg-albumen, and egg-shell samples after intentional exposure to a concentrated source of lead.

Conclusions

Findings of this pilot study showed that sub-chronic treatment of egg laying hens with ascorbic acid can reduce lead levels in different egg parts after intentional exposure to a concentrated source of lead. Supplementing feedstuffs and water with sources of ascorbic acid could be beneficial in reducing lead levels in hen egg tissues following environmental exposure. Further studies are still required to investigate if ascorbic acid can reduce lead levels in other chicken tissues.

Thiram-induced cytotoxicity and oxidative stress in human erythrocytes: an in vitro study

Tetramethylthiuram disulfide, commonly known as thiram, is an organosulfur compound which is used as a bactericide, fungicide and ectoparasiticide to prevent disease in seeds and crops. Being a fungicide there is a high probability of human occupational exposure to thiram and also via consumption of contaminated food. In this work, the cytotoxicity of thiram was studied under in vitro conditions using human erythrocytes as the cellular model. Erythrocytes were incubated with different concentrations of thiram (25-500 μM) for 4 h at 37 °C. Control cells (thiram untreated) were similarly incubated at 37 °C. Whole cells and hemolysates were analyzed for various biochemical parameters. Treatment of erythrocytes with thiram increased protein and lipid oxidation and hydrogen peroxide level in hemolysates but decreased glutathione and total sulfhydryl group content. This was accompanied by hemoglobin oxidation, heme degradation and release of free iron. Activities of all major antioxidant enzymes were inhibited. The antioxidant power of thiram treated erythrocytes was lowered resulting in decreased metal reducing and free radical quenching ability. These results suggest that thiram enhances the generation of reactive species that cause oxidative modification of cell components. This was confirmed by experiments that showed enhanced generation of reactive oxygen and nitrogen species in thiram treated erythrocytes. Activities of marker enzymes of glucose metabolism and erythrocyte membrane were also inhibited. All effects were seen in a thiram concentration-dependent manner. Electron microscopy further supported the damaging effect of thiram on erythrocytes. Thus thiram induces oxidative stress condition in human erythrocytes and causes oxidative modification of cell components.

Determination by chromatography and cytotoxotoxic and oxidative effects of pyriproxyfen and pyridalyl

Pyriproxyfen (PPF) is a larvicide, used to combat the proliferation of Aedes aegypti larvae. The objective of this study was to analyze the compounds of pyriproxyfen and pyridalyl (PYL) in a commercial larvicide to analyze the cytotoxic and oxidative effects of PPF and PYL. The toxic potential of PPF and PYL were assessed based on lethal concentration (LC₅₀) in Artemia salina, cytotoxicity based on the mitotic index and the chromosomal alterations in Allium cepa and the oxidative damage in Saccharomyces cerevisiae. The PPF and PYL compounds were identified by HPLC-PDA based on their retention times and spectral data. The wavelengths λ_max (258 nm) and (271 nm) of the UV spectrum of PYL and PPF and the retention times (R_T) (3.38 min) and (4.03 min), respectively. The toxicological potentials of PPF and PYL were significant at concentrations (1, 10, 100 and 1000 ppm), with an LC₅₀ of 48 h (0.5 ppm). PPF and PYL pointed out a cytotoxic effect in A. cepa at all concentrations (0.0001, 0.001, 0.01, 0.1, 1.0, 100 and 1000 ppm), genotoxic effect at concentrations only (0.0001; 0.1; 1; 100 and 1000 ppm), and mutagenic for concentrations (0.1, 100 and 1000 ppm). In relation S. cerevisiae, PPF e PYL prompted oxidative damage at concentrations (100 and 1000 ppm) in all strains (SODWT, Sod1, Sod2, Sod1Sod2, Cat1 and Sod1Cat1). Therefore, the PPF and PYL identificated in commercial larvicide by HPLC-PDA produced cytotoxic and oxidative effects that could cause health and ecosystem risks.

Vitamin C acts as a hepatoprotectant in carbofuran treated rat liver slices in vitro

The observations of liver slices when treated with different concentrations of carbofuran were as follows:-

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increased LPO

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decreased SOD, CAT, & protein content in all the treatments

The observations of liver slices when treated with different concentrations of carbofuran along with vitamin C were as follows:-

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the levels of LPO, SOD, CAT & total protein content reinstated towards normal level only in liver slices treated with low concentration

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at higher concentration of carbofuran treatment Vitamin C does not ameliorate the hepatic toxicity induced by carbofuran

The in vitro liver slice culture may prove to be a useful model for hepatotoxicological studies and Vitamin C, as a hepatoprotectant in mammalian system.

Carbamates, most commonly used pesticides in agricultural practices, have been reported to produce free radicals causing deleterious effects in animals. The present study was designed to assess the carbofuran induced oxidative stress in rat liver slices in vitro and also to evaluate protective role of vitamin C by incubating them in Krebs-Ringer HEPES Buffer (KRHB) containing incubation media (Williams medium E (WME) supplemented with glucose and antibiotics) with different concentrations of carbofuran. The results demonstrated that carbofuran caused significant increase in lipid peroxidation and inhibition in the activity of hepatic superoxide dismutase (SOD) in concentration dependent manner. The data with incubation medium reflected that carbofuran at lowest concentration caused an increase in SOD activity followed by its inhibition at higher concentration. Carbofuran treatment caused inhibition in the activity of catalase in liver slices and WME incubation medium. Pre-incubation of liver slices and the WME media with vitamin C restored the values of biochemical indices tested. The results indicated that carbofuran might induce oxidative stress in hepatocytes. The pretreatment with vitamin C may offer hepatoprotection from toxicity of pesticide at low concentration only.

Erythrocyte osmotic fragility and general health status of adolescent Sprague Dawley rats supplemented with Hibiscus sabdariffa aqueous calyx extracts as neonates followed by a high-fructose diet post-weaning

High-fructose diets (HFD) can cause oxidative damage to tissues including erythrocyte cell membranes. Hibiscus sabdariffa (HS) has protective antioxidant properties. Rats were used to investigate whether the consumption of HS by neonates would result in long-term effects on their erythrocyte osmotic fragility (EOF) and general health when later fed a high-fructose diet post-weaning through adolescence. Eighty of four-day-old Sprague Dawley rat pups were divided randomly into three treatment groups. The controls (n = 27) received distilled water at 10 ml/kg b. w, while the other groups received either 50 mg/kg (n = 28) or 500 mg/kg (n = 25) of an HS aqueous calyx extract orally till post-natal day 14. The rats in each group were weaned and divided into two subgroups; one continued on normal rat chow, and the other received fructose (20% w/v) in their drinking water for 30 days. Blood was collected in heparinised tubes and added to serially diluted (0.0-0.85%) phosphate-buffered saline to determine the EOF. Clinical markers of health status were determined with an automated chemical analyser. HS extracts did not programme metabolism in the growing rats to alter their general health and EOF in response to the HFD.

Curcumin Mediated Attenuation of Carbofuran Induced Oxidative Stress in Rat Brain

The indiscriminate use of carbofuran to improve crop productivity causes adverse effects in nontargets including mammalian systems. The objective of this study was to evaluate carbofuran induced oxidative stress in rat brain stem and its attenuation by curcumin, a herbal product. Out of 6 groups of rats, 2 groups received two different doses of carbofuran, that is, 15 and 30% of LD₅₀, respectively, for 30 days. Out of these, 2 groups receiving same doses of carbofuran were pretreated with curcumin (100 mg/kg body weight). The levels of antioxidants, TBARS, GSH, SOD, catalase, and GST were determined in rat brain stem. The 2 remaining groups served as placebo and curcumin treated, respectively. The data suggested that carbofuran at different doses caused significant alterations in the levels of TBARS and GSH in dose dependent manner. The TBARS and GSH contents were elevated. The activities of SOD, catalase, and GST were significantly inhibited at both doses of carbofuran. The ratio of P/A was also found to be sharply increased. The pretreatment of curcumin exhibited significant protection from carbofuran induced toxicity. The results suggested that carbofuran at sublethal doses was able to induce oxidative stress in rat brain which could be attenuated by curcumin.

Studies on the ameliorative effect of curcumin on carbofuran induced perturbations in the activity of lactate dehydrogenase in wistar rats

Carbofuran is known to inhibit neurotransmission system of insects. The present study was undertaken to evaluate the possible ameliorative effect of curcumin on carbofuran induced alterations in energy metabolism in brain and liver of rats. The results demonstrate that carbofuran caused a significant inhibition of lactate dehydrogenase (LDH) activity in rat liver but an increase in LDH activity in the brain. Increased LDH activity was also observed in the serum indicating organ damage in treated animals. Carbofuran caused an increase in level of pyruvic acid in rat liver but a decrease in the brain. A decrease in the level of soluble protein was also observed in the tissues studied. Pretreatment of animals with curcumin resulted in significant amelioration of the altered indices. These results indicate that carbofuran at sub lethal concentrations may adversely alter energy metabolism in brain and liver of non-target mammalian systems. Pretreatment of animals with curcumin may exhibit a potential to mitigate the carbofuran induced toxicity.

Induction of mitotic and chromosomal abnormalities on Allium cepa cells by pesticides imidacloprid and sulfentrazone and the mixture of them

To evaluate the cytotoxic and genotoxic effects of low concentrations of pesticides in non-target organisms, seeds of Allium cepa were exposed for 24 h to the imidacloprid insecticide, sulfentrazone herbicide and to the mixture of them, followed by recovery periods of 48 and 72 h. Imidacloprid results indicated an indirect genotoxic effect by inducing different types of chromosome aberration (CA), mainly bridges and chromosomal adherences. Cells with micronucleus (MN) were not significant in the analyzed meristems. Moreover, the 72-h recovery tests indicated that the two lower concentrations of the insecticide (0.036 and 0.36 g L(-1)) had their genotoxic effects minimized after discontinuation of treatment, differently to the observed for the field concentration (3.6 g L(-1)). Sulfentrazone herbicide at field concentration (6 g L(-1)) caused cytotoxic effects by inducing nuclear fragmentation and inhibition of cell division. The other concentrations (0.06, 0.6 and 1.2 g L(-1)) indicated genotoxic effects for this herbicide. The concentration of 0.06 g L(-1) induced persistent effects that could be visualized both by the induction of CA in the recovery times as by the presence of MN in meristematic and F1 cells. The induction of MN by this lowest concentration was associated with the great amount of breakage, losses and chromosomal bridges. The mixture of pesticides induced genotoxic and cytotoxic effects, by reducing the MI of the cells. The chromosomal damage induced by the mixture of pesticides was not persistent to the cells, since such damage was minimized 72 h after the interruption of the exposure.

The stability of blood fatty acids during storage and potential mechanisms of degradation: A review

Fatty acids in blood samples, particularly polyunsaturated fatty acids (PUFAs), are susceptible to degradation through peroxidation reactions during long-term storage. Storage of blood samples is necessary in almost all studies and is crucial for larger clinical studies and in field research settings where it is not plausible for analytical infrastructure. Despite this, PUFA stability during blood storage is often overlooked. This review introduces and discusses lipid peroxidation and popular strategies employed to prevent or minimize peroxidation reactions during fatty acid analysis. Further, an in-depth examination of fatty acid stability during storage of blood is discussed in detail for all blood fractions including plasma/serum, erythrocytes and whole blood stored both in cryovials and on chromatography paper before discussing the associated mechanisms of degradation during storage. To our knowledge this is the first review of its kind and will provide researchers with the necessary information to confidently store blood samples for fatty acid analysis.

Hepatoprotective Effect of Citrus limon Fruit Extract against Carbofuran Induced Toxicity in Wistar Rats

Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol methylcarbamate), is known to induce oxidative stress and to cause inhibition of acetylcholinesterase activity. The present work was envisaged to evaluate the effect of carbofuran on redox indices and its interactions with hepatic markers in rat. The ameliorating effect of Citrus limon fruit extract on carbofuran induced toxicity was also monitored. The results indicated that carbofuran treatment caused significant alterations in the levels of activities of AST, ALT, and LDH in liver tissues and serum. The levels of enzymatic oxidative stress markers such as SOD and catalase and nonenzymatic redox molecules such as total thiol, GSH, and protein thiol also showed significant perturbations in rat liver due to carbofuran treatment. The administration of Citrus limon fruit extract, however, was able to markedly ameliorate the toxicity of carbofuran by protecting the levels of aforesaid biomarkers to near normal levels. The ameliorative effect of Citrus limon fruit extract may be due to the presence of different antioxidants in it which may neutralize the ROS and RNS generated in the body tissue due to pesticide stress. These results suggested that Citrus limon fruit extract may be utilized as a potential supplement in proper management of pesticide intoxication in association with relevant therapeutics.

Analysis of the genotoxic potential of low concentrations of Malathion on the Allium cepa cells and rat hepatoma tissue culture

Based on the concentration of Malathion used in the field, we evaluated the genotoxic potential of low concentrations of this insecticide on meristematic and F1 cells of Allium cepa and on rat hepatoma tissue culture (HTC cells). In the A. cepa, chromosomal aberrations (CAs), micronuclei (MN), and mitotic index (MI) were evaluated by exposing the cells at 1.5, 0.75, 0.37, and 0.18mg/mL of Malathion for 24 and 48hr of exposure and 48hr of recovery time. The results showed that all concentrations were genotoxic to A. cepa cells. However, the analysis of the MI has showed non-relevant effects. Chromosomal bridges were the CA more frequently induced, indicating the clastogenic action of Malathion. After the recovery period, the higher concentrations continued to induce genotoxic effects, unlike the observed for the lowest concentrations tested. In HTC cells, the genotoxicity of Malathion was evaluated by the MN test and the comet assay by exposing the cells at 0.09, 0.009, and 0.0009mg/5mL culture medium, for 24hr of exposure. In the comet assay, all the concentrations induced genotoxicity in the HTC cells. In the MN test, no significant induction of MN was observed. The genotoxicity induced by the low concentrations of Malathion presented in this work highlights the importance of studying the effects of low concentrations of this pesticide and demonstrates the efficiency of these two test systems for the detection of genetic damage promoted by Malathion.

Effects of chemical and thermal stress on acetylcholinesterase activity in the brain of the bank vole, Myodes glareolus

One of the most important issues in ecotoxicology is better understanding the effects of interactions between chemical pollutants and physical environmental factors on animals. To fill this knowledge gap, changes in the activity of acetylcholinesterase (AChE) in the brain samples of bank voles Myodes (Clethrionomys) glareolus due to temperature effects, and two chemical stressors were studied in a full factorial laboratory experiment (27 treatments). The experiment was divided into three phases: acclimatisation (3 days), intoxication (42 days) and elimination (21 days). During the intoxication phase, animals were orally exposed to different concentrations of either nickel (0, 300 or 800 mg Ni/kg food), chlorpyrifos (CPF) (0, 50 or 350 mg CPF/kg food) or a mixture of both chemicals. During the acclimatisation and elimination phases, the bank voles were given uncontaminated food. The experiment was conducted at three different temperatures (10, 20 or 30 °C), and a 12 h:12 h light:dark regime. The animals were sacrificed at 0, 5, 10, 20, 42, 49 and 63 days after the beginning of the intoxication, and brain samples were obtained for chemical analysis. The nickel accumulation in the brain depended on the level of nickel exposure and on interactions between the temperature and other factors. Nickel exhibited no effect on AChE activity. In contrast, AChE was drastically inhibited by chlorpyrifos and low temperature, but interactions between all factors significantly influenced the enzyme activity during the elimination phase of the experiment. High mortality was observed in the groups exposed to high concentrations of nickel and chlorpyrifos.

Carbofuran Induced Oxidative Stress in Rat Heart: Ameliorative Effect of Vitamin C

The aim of this study was to evaluate the effect of carbofuran on the levels of certain biomarkers in heart of rat exposed to sublethal concentrations of pesticide for 30 days after each interval of 24 h. The ameliorative effect of vitamin C by pretreatment of rats was also monitored. The results indicated that the activities of acetylcholinesterase and lactate dehydrogenase (LDH) decreased significantly in rat heart tissues, the extent of inhibition being concentration dependent. In contrast, the level of LDH increased in serum. The levels of malondialdehyde, total thiols, and glutathione were significantly elevated whereas the activities of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione-S-transferase were remarkably decreased in rat heart tissues. The serum concentrations of cholesterol increased by 47 and 77% and high density lipids decreased by 35 and 64%, respectively, due to exposure to 5 and 10% LD50 of carbofuran. The prior treatment of rats with vitamin C (100 mg kg−1 body weight) exerted significant ameliorative effect. The recovery was higher at low carbofuran concentration (5%) tested. The results indicated that carbofuran induced oxidative stress and caused damage to cardiac tissues, which could be recovered by prior application of vitamin C.

EPA and DHA levels in whole blood decrease more rapidly when stored at -20 °C as compared with room temperature, 4 and -75 °C

High-throughput n-3 fatty acid profiling is enabled by collection techniques such as venous whole blood and fingertip prick (FTP) sampling, but the resulting increased sample numbers increases storage demand. Highly unsaturated fatty acids (HUFA) in erythrocytes are susceptible to oxidation, but this tendency is poorly characterized in venous and FTP whole blood. Presently, whole blood samples with low and high n-3 content collected with ethylenediaminetetraacetic acid were stored on chromatography paper with and without BHT pre-treatment for up to 180 days at different temperatures (room, 4, -20, -75 °C). Whole blood prepared with heparin and BHT and stored in cryovials was also examined. Eicosapentaenoic acid (EPA, 20:5n-3) + docosahexaenoic acid (DHA, 22:6n-3) is relatively stable when stored at -75 °C under various conditions but rapidly decreases in whole blood when stored at -20 °C. At -20 °C, BHT + heparin prepared whole blood can prevent decreases in cryovials up to 180 days but BHT only slows the decreases on chromatography paper. Surprisingly, whole blood stored at 4 °C and room temperature was less susceptible to decreases in EPA + DHA as compared with -20 °C storage. Assessments of n-3 blood biomarkers indicate the % n-3 HUFA in total HUFA was more stable as compared with the sum of the relative % of EPA + DHA. In conclusion, FTP and venous whole blood for fatty acid analysis should be stored at -75 °C whenever possible. In the absence of -75 °C storage conditions, BHT should be added and 4 °C or room temperature appear to be better alternatives to -20 °C.

Pesticides-induced biochemical alterations in occupational North Indian suburban population

Pesticides are used in agriculture to protect crops from insects–pests. Most of the field workers of North Indian population are exposed to commonly used insecticides. In the present study, pesticides induced oxidative stress as well as alterations in the level of acetylcholinesterase (AChE) in a total of 70 male healthy agricultural sprayers, exposed to pesticides for about 5 years, were studied and the results were compared with 70 controls. The levels of antioxidant enzymes (superoxide dismutase, CAT, glutathione- S-transferase and glutathione peroxidase), AChE, lipid peroxidation and glutathione (GSH) contents were determined in their blood erythrocytes (red blood cells (RBCs)). The results indicated significant increase in the levels of malondialdehyde as well as the activities of antioxidant enzymes in pesticide-exposed individuals. The levels of GSH, RBC-AChE activity and plasma antioxidant potential were sharply decreased when compared with control subjects. The ferric-reducing ability of plasma (FRAP) assay was carried out to evaluate the antioxidant potential of pesticide in exposed as well as healthy controls. A significant positive correlation was observed between plasma FRAP value and the activity of AChE from RBCs in pesticides sprayers. Furthermore, these results were supported by enhanced messenger RNA expressions of cytochrome P450 isoform 2E1 (CYP2E1) and gutathione- S-transferase isoform pi (GST-pi) in the white blood cells of the randomly selected pesticide-exposed individuals. The decreased GSH level in human red blood cells accompanied by increase in the levels of the activities of antioxidative enzymes and over expressions of CYP2E1 and GST-pi is an indicative of oxidative stress in pesticides-exposed individuals. The reduced activity of AChE indicates possible occurrence of perturbations in blood as well as neurotoxicity in pesticide sprayers.

Quercetin protected isolated human erythrocytes against mancozeb-induced oxidative stress

Mancozeb is a fungicide belonging to the ethylene-bisdithiocarbamate group and is widely used in agriculture. The aim of this study was to examine the protective effect of quercetin (QRN) against oxidative stress induced by mancozeb in human erythrocytes. In order to verify this, 5 ml of venous blood was collected and the erythrocytes were separated and divided into equal parts. One part was incubated with different concentrations of mancozeb (0, 10, 30, 100 µM) for 4 h at 37°C. The other part was preincubated with QRN (40 and 80 μM) for 30 min, followed by mancozeb (0, 10, 30, 100 µM) incubation for 4 h. We found reduction in the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) along with elevated levels of lipid peroxide (LPO) in erythrocytes incubated with 30 and 100 µm of mancozeb. Pre-incubation with QRN (80 μM) reversed oxidative stress induced by mancozeb (30 μM) and inhibited LPO induced at 100 μM by 64.36%. QRN also reduced the haemolytic effect on erythrocytes but could not prevent the induction of haemolysis by mancozeb. Therefore, these results suggest that QRN may play a role in preventing the oxidative stress induced by mancozeb in human erythrocytes.

Attenuation of cellular antioxidant defense mechanisms in kidney of rats intoxicated with carbofuran

Carbofuran, an anticholinestrase carbamate, is commonly used as an insecticide. Its toxic effect on kidney is less established. The present study was designed to investigate the effect of carbofuran on kidneys and to understand the mechanism involved in its nephrotoxicity. Male Wistar rats were divided into two groups of eight animals each; control animals received sunflower oil (vehicle) and carbofuran exposed animals were treated with carbofuran (1 mg/kg body weight) orally for 28 days. At the end of the treatment, significant increase was observed in urea and creatinine levels in serum along with the inhibition of acetylcholinesterase, suggesting nephrotoxicity. The antioxidant defense system of animals treated with carbofuran was altered in terms of increased lipid peroxidation, reduced glutathione, and total thiols and decreased activity of antioxidant enzymes (superoxide dismutase and catalase). The results indicate that carbofuran is nephrotoxic and increased oxidative stress appears to be involved in its nephrotoxic effects.

Acute effects of methiocarb on oxidative damage and the protective effects of vitamin E and taurine in the liver and kidney of Wistar rats

Methiocarb (MC) is a widely used carbamate pesticide in agriculture and health programs. Although the main molecular mechanism of carbamate toxicity involves acetylcholinesterase inhibition, studies have also implicated the induction of oxidative stress. Therefore, the present study was aimed to evaluate the effect of acute MC exposure on lipid peroxidation, antioxidant defense systems, histological changes in Wistar rats and the protective effect of pretreatment with vitamin E and taurine. A total of 48 rats were randomly divided into six groups. Rats in group I were given corn oil, while those in group III were dosed with vitamin E (100 mg/kg body weight (b.w.)) and in group V were dosed with taurine (50 mg/kg b.w.). Rats in group II were administered with MC only (25 mg/kg b.w., 1/4 of median lethal dose (LD(50))), while those in groups IV and VI were pretreated with vitamin E (100 mg/kg b.w.) and taurine (50 mg/kg b.w.) for 20 days, respectively, and then exposed to MC (25 mg/kg b.w.). The rats administered with MC showed significant increase in the levels of malondialdehyde in the liver and kidney as an index of lipid peroxidation. Levels of glutathione and activities of superoxide dismutase, catalase and glutathione peroxidase were significantly increased, while activity of glutathione reductase remained unchanged in both the tissues after MC treatment. Mild degenerative histological changes were observed in liver tissue, while the changes in kidney tissue were more severe then liver after MC treatment. Pretreatment with vitamin E and taurine resulted in a significant decrease in the lipid peroxidation and alleviating effects on antioxidant defense systems in both the tissues, while protective effects on the histological changes were shown only in kidney when compared with liver. In conclusion, the study has demonstrated that the acute MC exposure in Wistar rats caused oxidative damage on liver and kidney, which were partly ameliorated by the pretreatment of vitamin E and taurine.

Caffeic acid and quercetin protect erythrocytes against the oxidative stress and the genotoxic effects of lambda-cyhalothrin in vitro

Lambda-cyhalothrin (LTC) is a synthetic pyrethroid with a broad spectrum of insecticidal and acaricidal activities used to control wide range of insect pests in a variety of applications. The aim of this study was to examine (i) the potency of LTC to induce oxidative stress response in rat erythrocytes in vitro and (ii) the role of caffeic acid (20 μM) and/or quercetin (10 μM) in preventing the cytotoxic effects. Erythrocytes were divided into four portions. The erythrocytes of the first portion were incubated for 4 h at 37°C with different concentrations (0, 50 and 100 μM) of LTC. The others portions were pretreated with caffeic acid and/or quercetin for 30 min prior to LTC incubation. Lipid peroxidation, protein oxidation, antioxidant enzyme activities and DNA damage were examined. LTC at different concentrations causes increased levels of lipid peroxidation, protein oxidation, DNA damage and decreased antioxidant enzyme activities. Combined caffeic acid and quercetin pretreatments significantly reduced the levels of lipid peroxidation markers, that is thiobarbituric acid reactive substance (TBARS), protein carbonyls (PCO) and decreased DNA damage in LTC portion. Further, combined caffeic acid and quercetin pretreatment maintain antioxidant enzyme activities and glutathione content near to normal values. These results suggest that LTC exerts its toxic effect by increasing lipid peroxidation, altering the antioxidant enzyme activities and DNA damage. Caffeic acid and quercetin pretreatments prevent the toxic effects of LTC, suggesting their role as a potential antioxidant.

Protective effect of Ginkgo biloba L. leaf extract against glyphosate toxicity in Swiss albino mice

The aim of the present study was to investigate the protective role of Ginkgo biloba L. leaf extract against the active agent of Roundup® herbicide (Monsanto, Creve Coeur, MO, USA). The Swiss Albino mice were randomly divided into six groups, with each group consisting of six animals: Group I (control) received an intraperitoneal injection of dimethyl sulfoxide (0.2 mL, once only), Group II received glyphosate at a dose of 50 mg/kg of body weight, Group III received G. biloba at a dose of 50 mg/kg of body weight, Group IV received G. biloba at a dose of 150 mg/kg of body weight, Group V received G. biloba (50 mg/kg of body weight) and glyphosate (50 mg/kg of body weight), and Group VI received G. biloba (150 mg/kg of body weight) and glyphosate (50 mg/kg of body weight). The single dose of glyphosate was given intraperitoneally. Animals from all the groups were sacrificed at the end of 72 hours, and their blood, bone marrow, and liver and kidney tissues were analyzed for aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine, malondialdehyde (MDA), and glutathione (GSH) levels and the presence of micronucleus (MN), chromosomal aberrations (CAs), and pathological damages. The results indicated that serum AST, ALT, BUN, and creatinine levels significantly increased in mice treated with glyphosate alone compared with the other groups (P<.05). Besides, glyphosate-induced oxidative damage caused a significant decrease in GSH levels and a significant increase in MDA levels of the liver and kidney tissues. Moreover, glyphosate alone-treated mice presented higher frequencies of CAs, MNs, and abnormal metaphases compared with the controls (P<.05). These mice also displayed a lower mean mitotic index than the controls (P<.05). Treatment with G. biloba produced amelioration in indices of hepatotoxicity, nephrotoxicity, lipid peroxidation, and genotoxicity relative to Group II. Each dose of G. biloba provided significant protection against glyphosate-induced toxicity, and the strongest effect was observed at a dose of 150 mg/kg of body weight. Thus, in vivo results showed that G. biloba extract is a potent protector against glyphosate-induced toxicity, and its protective role is dose-dependent.

The antioxidant effect of wheat germ oil on subchronic coumaphos exposure in mice

Forty-eight male Balb/C mice, allocated to 4 equal groups, constituted the material of the study. The first group was maintained as the control group and was administered solely with a vehicle, which was used to dissolve coumaphos in the third and fourth groups. The second group was administered with 1.5 ml/kg.bw/day (∼1400 mg/kg.bw/day) of wheat germ oil. The third group received 5.5mg/kg.bw/day (1/10 LD50(oral)) of coumaphos. Finally, the fourth group was given both coumaphos and wheat germ oil at the doses indicated above. In all groups, the compounds were given directly into the stomach using a gastric tube, and treatment was continued for a period of 45 days. At the end of the 45th day, the liver, lungs, kidneys, brain, heart and spleen were extirpated in all of the animals. Tissue homogenates prepared from the tissue specimens were analysed for malondialdehyde (MDA) levels and catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. In conclusion, it was determined that coumaphos led to adverse alterations in the majority of the oxidative stress markers investigated. The administration of wheat germ oil alleviated the coumpahos-induced adverse effects detected in the tissues examined.

The protective effect of royal jelly on chronic lambda-cyhalothrin toxicity: serum biochemical parameters, lipid peroxidation, and genotoxic and histopathological alterations in swiss albino mice

The present study was undertaken to investigate the protective effect of royal jelly (RJ) against toxicity induced by a synthetic pyrethroid insecticide, lambda-cyhalothrin (LCT), in Swiss albino mice. Animals were randomly divided into six groups of six animals each. The control group received distilled water alone, whereas mice in the treatment groups received RJ alone (100 or 250 mg/kg of body weight), LCT alone (668 ppm), or RJ+LCT for 21 days. All mice (100%) survived until the end of experiment and were sacrificed at the end of 24 hours. Blood, bone marrow, and liver and kidney tissues were analyzed for aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine, malondialdehyde (MDA), and reduced glutathione (GSH) levels and micronucleus (MN) frequency, chromosomal aberrations (CAs), and pathological damages. Serum AST, ALT, BUN, and creatinine levels were elevated in mice treated with LCT alone compared with the other tested groups (P<.05). LCT-induced oxidative damage caused a significant decrease in GSH levels and a significant rise in MDA levels of liver and kidney tissues. LCT alone-treated mice presented higher frequencies (P<.05) of MNs, CAs, and abnormal metaphases compared with the controls; moreover, the mitotic index was lower than in controls (P<.05). Oral treatment with RJ significantly ameliorated the indices of hepatotoxicity, nephrotoxicity, lipid peroxidation, and genotoxicity induced by LCT. Both doses of RJ tested provided significant protection against LCT-induced toxicity, and its strongest effect was observed at the dose level of 250 mg/kg of body weight. In vivo results suggest that RJ is a potent antioxidant against LCT-induced toxicity, and its protective effect is dose dependent.

Fenvalerate induced hepatic oxidative stress in selenium- and/or iodine-deficient rats

Considering the potential adverse effects of selenium and iodine deficiencies, and frequency of intensive but improper use of insecticides, this study was designed to evaluate the effects of a pyrethroid insecticide, fenvalerate, on the oxidant/antioxidant status of liver using a rat model of iodine and/or selenium deficiency. The study was conducted on eight groups of 3-week old Wistar rats. Iodine and/or selenium deficiency was introduced by feeding the animals with a diet containing <0.005 mg selenium/kg and/or supplying with 1% sodium perchlorate containing drinking water for a period of 7 weeks. Fenvalerate exposure (100 mg/kg/d, i.p., for the last 7 days) in normal rats increased hepatic glutathione peroxidase activity and lipid peroxidation, decreased glutathione content, but did not change the activities of catalase or any of the superoxide dismutase forms; in iodine-deficient animals caused only the elevation of lipid peroxidation; in selenium-deficient animals and in combined iodine/selenium deficiency decreased glutathione peroxidase, increased catalase activities and lipid peroxidation, and decreased all the forms of superoxide dismutase activity only in combined deficiency. These results suggested that fenvalerate is an oxidant stress inducer in rat liver, and its potential effects on pro-oxidant/antioxidant balance may also be important for human populations, particularly with iodine and/or selenium deficiencies.

Ameliorative effect of vitamin C on chronic chlorpyrifos-induced erythrocyte osmotic fragility in Wistar rats

Chronic exposure to chlorpyrifos (CPF) has been shown to cause increased lipoperoxidative changes in the erythrocyte membranes. The relationship between chronic CPF-induced lipoperoxidative changes and erythrocyte fragility has not been elucidated. The aim of the present study is to evaluate the role of lipoperoxidation on CPF-induced erythrocyte fragility and the ameliorative effect of vitamin C. Twenty animals divided at random into four groups of five animals each served as subject for this study. Rats in group I served as the control group and were given only soya oil at a dose of 2 mL/kg body weight (b.w.). Rats in group II were dosed with vitamin C (100 mg/kg b.w.) and then supplemented with soya oil (2 mL/kg b.w.), while those in group III were administered with CPF only at a dose of 10.6 mg/kg b.w. (~one-eighth of the previously determined median lethal dose [LD(50)]). Rats in group IV were pretreated with 100 mg/kg b.w. of vitamin C, and then dosed with CPF at a dose of 10.6 mg/kg b.w., 30 min later. The different treatment regimens were orally administered daily for a period of 17 weeks. Blood collected from the animals at the end of the test period were analyzed for erythrocyte osmotic fragility and malonaldehyde (MDA) concentration as an index of lipid peroxidation. The study showed that CPF caused significant increase in erythrocyte fragility and MDA concentration, which were ameliorated by pretreatment with vitamin C. In conclusion, the study showed that CPF-evoked erythrocyte fragility due to increased lipoperoxidative changes was ameliorated by pretreatment with vitamin C.

Influence of vitamin C supplementation on lead-induced histopathological alterations in male rats

This study is intended to evaluate the efficacy of vitamin C (VC) in ameliorating the detrimental effects of long-term lead intoxication on the liver, kidneys, brain and testes as assessed by histopathology. A total of forty male Wistar rats (six-weeks-old) was divided into 4 groups: control group; lead-acetate (PbAc)-treated group (20 mgPbAc/kgbwt); PbAc+VC-treated group (20 mgPbAc/kgbwt plus 20 mg VC/kgbwt); and VC-treated group (20 mgVC/kgbwt). The Experimental period was lasted for 60 successive days in which PbAc was administered once daily while VC was supplemented every other day using intra-gastric intubation. At the end of the experimental period, all rats were sacrificed and pathological examinations were performed. Control and VC-supplemented rats showed normal liver, kidney, brain, and testes histology. In contrast, the liver of PbAc-intoxicated rats exhibited degenerated hepatocytes and portal inflammatory cell infiltrations. The kidneys showed degenerated glomeruli and formation of karyomegalic cells containing intranuclear inclusions in the proximal tubular epithelium. Cerebellar edema, cerebral satellitosis and encephalomalacia observed in the brain. Testicular tissues showed arrest of spermatogenesis and interstitial edema. Co-administration of VC with PbAc diminished the severity of pathological changes and reduced the number of affected organs compared to PbAc-intoxicated rats. These results show that low level of VC ameliorated and mitigated the adverse pathological impacts of chronic lead toxicity.

Toxic effects of lambda-cyhalothrin, a synthetic pyrethroid pesticide, on the rat kidney: Involvement of oxidative stress and protective role of ascorbic acid

Lambda-cyhalothrin is a synthetic pyrethroid insecticide used worldwide in agriculture, home pest control, protection of foodstuff and disease vector control. The objective of this study was to investigate the propensity of lambda-cyhalothrin (LTC) to induce oxidative stress, changes in biochemical parameters and enzyme activities in the kidney of male rats and its possible attenuation by Vitamin C (vit C). Renal function, histopathology, tissue malondialdehyde (MDA), protein carbonyl (PCO) levels, antioxidant enzyme activities and reduced glutathione (GSH) levels were evaluated. Exposure of rats to lambda-cyhalothrin, during 3 weeks, caused a significant increase in kidney MDA and protein carbonyl levels (p<0.01) as compared to controls. Co-administration of vitamin C was effective in reducing MDA and PCO levels. The kidney of LTC-treated rats exhibited severe vacuolations, cells infiltration and widened tubular lumen. The activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) were significantly decreased due to lambda-cyhalothrin exposure. Co-administration of vitamin C ameliorated the increase in enzymatic activities of aminotransferases (AST and ALT), lactate dehydrogenase (LDH), creatinine and urea levels and improved the antioxidant status. These data indicated the protective role of ascorbic acid against lambda-cyhalothrin-induced nephrotoxicity and suggested a significant contribution of its antioxidant property to these beneficial effects.