Cd-induced Lipid Peroxidation Research Articles

Antioxidant activity of Carica papaya &Persea americana fruits against cadmium induced neurotoxicity, nephrotoxicity, and hepatotoxicity in rats with a computational approach

BackgroundCadmium is widely reported to interfere with the proper functioning of cells by disrupting cellular redox balance, causing apoptosis, and leading to hepatocellular damage, neurotoxicity, pulmonary edema, cancer, and cardiac and neurodegenerative diseases. Treatment of Cd toxicity with drugs brings undesirable side effects, making it necessary to remove Cd from the body safely without harmful effects. ObjectiveThis study aimed to determine how Cd causing malfunctioning of cells could be treated with antioxidant-rich avocado and papaya fruit juices. This work fixated on elucidating and comparing the effects of avocado and papaya fruit juice on Cd-dependent impairment in memory and spatial learning. In addition, various markers of tissue damage, such as the concentration of biomarkers in liver and kidney tissue, the expression of antioxidant enzymes and Cd-induced lipid peroxidation, were analyzed. Methodologyin silico studies of the phytochemical constituents of avocado and papaya (ligands) were docked against antioxidant enzymes Catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) as macromolecules showed strong hydrogen binding with significant binding capacities. To develop the Cd in vivo model, rats were administered CdCl2 (200 ppm) in drinking water for 7 weeks. After induction of Cd toxicity, rats were post-treated with avocado and papaya (10% w/v each) in a standard diet. After post-treatment, memory and learning were assessed using the Morris water maze behavioural test. Biochemical tests for liver and kidney biomarkers were monitored. To determine the level of ROS, lipid peroxidation was determined by Malondialdehyde (MDA) assay. Gene expression of SOD, CAT and GPx were determined via qRT-PCR. ResultsThis study demonstrated that Cd accumulation in the liver, kidney and hippocampal tissues was reduced after treatment with avocado and papaya. SOD, CAT and GPX gene expression were upregulated after avocado and papaya juice treatment. Moreover, a comparative analysis between avocado and papaya fruit juices clarified that papaya has more active potential for improving memory and learning, upregulating the expression of antioxidant enzymes, and reducing lipid peroxidation in the liver, kidney, and hippocampus. ConclusionThis study suggests that a diet containing papaya and avocado can help treat the lethal effects caused by Cd. Because their active constituents can improve health at the cellular and molecular levels.

Tryptophan pretreatment adjusts transcriptome and metabolome profiles to alleviate cadmium toxicity in Arabidopsis

Cadmium (Cd) is highly toxic to all organisms including plants, and recently tryptophan (Trp) pretreatment of plant seedlings is shown to improve Cd tolerance. But the underlying mechanism remains largely unknown. In this study, we used Arabidopsis (Arabidopsis thaliana) to determine the physiological relevance of Trp pretreatment in alleviating Cd toxicity in plants and explore its molecular mechanism with a focus on the metabolic pathways. The results showed that Trp pretreatment maintained the biomass and root lengths, relieved Cd-induced lipid peroxidation, and reduced Cd transport to the shoots, and eventually improved the response against Cd in Arabidopsis seedlings. The integrative analyses of the transcriptome and metabolome further revealed that Trp pretreatment alleviated Cd toxicity not only through a known mechanism of producing a major auxin indole-3-acetic acid and maintaining its levels, but also through two previously unrecognized mechanisms: increasing the area and strength of cell walls by promoting lignification to further reduce Cd entry, and fine-tuning Cd detoxification products derived from sulfur-containing amino acid metabolism. Our findings thereby provide deep mechanical insights into how Trp alleviates Cd toxicity in plants.

PvERF104 confers cadmium tolerance in Arabidopsis: Evidence for metal-responsive element-binding transcription factors

Cadmium (Cd) is highly toxic to all organisms including plants, and transcription factors are essential regulators for Cd-responsive genes. In animals, metal-responsive transcription factor-1 (MTF-1) is a unique and main transcriptional activator for heavy metal detoxification through binding metal-responsive elements (MREs). However, plants have no homologs of MTF-1, and whether there are MRE-binding transcription factors in plants remain largely unknown. Previously, we identified an MRE-binding transcription factor 1 (PvMTF-1) from the bean (Phaseolus vulgaris). Unfortunately, PvMTF-1 is an orphan protein and cannot represent a conserved MRE-binding transcription factor family in plants. Here, we isolated and characterized bean ethylene response transcription factor (ERF) 104 (PvERF104) as a functional MRE-binding transcription factor. PvERF104 was isolated from the bean by yeast one-hybrid screens using the MRE as a bait. PvERF104 acted as an MRE-dependent transcriptional repressor. Expression of PvERF104 relieved Cd-induced lipid peroxidation and reduced Cd accumulation, and then moderately improved Cd tolerance in Arabidopsis. Further analyses showed that PvERF104 directly or indirectly regulated the expression of MRE-containing Cd stress-related genes, and subsequently influenced Cd tolerance. Thus, PvERF104 represents a member of ERF-type MRE-binding transcription factors. Our findings thereby provide new insights into the roles and mechanisms of MRE-binding transcription factors in plants against Cd. Data AvailabilityData will be made available on request.

Different nanobubbles mitigate cadmium toxicity and accumulation of rice (Oryza sativa L.) seedlings in hydroponic cultures

Cadmium (Cd) contamination can pose a severe threat to food production and human health. The accumulation of Cd in rice will decrease rice biomass, photosynthetic activity, and antioxidant capacity, affecting crop yield. The effects of different nanobubbles on the growth and Cd accumulation of rice seedlings under hydroponic conditions were investigated in this study. The results showed that the biomass, photosynthetic pigment content, and antioxidant enzyme activity of rice seedlings decreased when treated with Cd alone and that Cd induced lipid peroxidation in rice seedlings. However, when different types of nanobubbles were introduced into the nutrient solution, the bioavailability of Cd in the solution was reduced. As a result, the Cd content in rice was significantly decreased compared to treatment with Cd alone. Nanobubbles increased the biomass of rice, enhanced photosynthesis, and improved the antioxidant capacity of rice by increasing antioxidant enzyme activities to alleviate Cd-induced oxidative stress. At the same time, nanobubbles increased the Fe content in rice, which decreased the Cd content, as Cd is antagonistic to Fe. In conclusion, these results suggested that nanobubbles are a potential method of mitigating Cd stress that may help to improve rice yield and could be further explored in production.

Cadmium induces liver dysfunction and ferroptosis through the endoplasmic stress-ferritinophagy axis

Cadmium (Cd) is a type of high-risk heavy metal that can damage organs such as the liver, but its mechanism is not yet clear. Ferroptosis is a newly discovered mode of regulatory cell death. We explored whether ferroptosis is involved in Cd-induced liver damage and the underlying mechanism. Our research showed that Cd induced liver damage by inducing ferroptosis, and the use of ferroptosis inhibitors reduced the degree of liver damage. Moreover, the occurrence of ferroptosis was accompanied by the activation of the PERK-eIF2α-ATF4-CHOP signaling pathway, and inhibiting endoplasmic reticulum (ER) stress reduced ferroptosis demonstrating that ferroptosis induced by Cd is dependent on ER stress. In addition, chloroquine, a common autophagy inhibitor, mitigated ferroptosis caused by Cd exposure. Then, the iron chelator deferoxamine reduced Cd-induced lipid peroxidation and cell death, demonstrating that the iron regulation disorder caused by ferritin phagocytosis contributes to the Cd-induced ferroptosis. In conclusion, our results show that Cd-induced liver toxicity is accompanied by ferroptosis, which contributes to Cd inducing oxidative stress to trigger autophagy and ER stress to promote the process of ferroptosis.

Improvement of alfalfa resistance against Cd stress through rhizobia and arbuscular mycorrhiza fungi co-inoculation in Cd-contaminated soil.

Rhizobia and arbuscular mycorrhiza fungi (AMF) are important symbiotic microbes that are advantageous to plants growing in metal-contaminated soil. However, it remains unclear how inoculated microbes affect rhizosphere microbial communities or whether subsequent changes in rhizosphere microbiomes contribute to improving plant resistance under metal stress. This study investigated the effects of rhizobia and AMF inoculation on alfalfa resistance to Cd stress. The response of rhizosphere microbial communities to inoculation and its role in increasing alfalfa' ability to cope with stress were further analyzed using high-throughput sequencing of 16S and ITS rRNA genes. Results showed that single rhizobia or AMF inoculation significantly improved alfalfa resistance to Cd stress, while their co-inoculation resulted in the greatest overall improvement. Improved resistance was reflected by the significant mitigation of Cd-induced lipid peroxidation and reactive oxygen species (ROS) stress caused by increases in antioxidant enzyme activities along with co-inoculation. Furthermore, co-inoculation significantly altered the rhizosphere microbial community structure by decreasing fungal community diversity and increasing bacterial community diversity. Results of partial least squares path modeling (PLS-PM) and variation partitioning analysis (VPA) showed that the rhizosphere bacterial community predominated over the fungal community with respected to improvements in resistance to Cd stress under the co-inoculation treatments. This improvement was specifically seen in the enrichment of certain key bacterial taxa (including Proteobacteria, Actinobacteria, Acidobacteria, and Chloroflexi) induced by the rhizobia and AMF co-inoculation, enhancing alfalfa' ability to uptake rhizosphere nutrients and reduce its release of photosynthetically-derived carbon (C) into soil. Our findings revealed that the co-inoculation of multiple symbiotic microbes can assist plants to effectively cope with Cd stress, providing a greater understanding of rhizosphere bacterial taxa in the microbe-induced phytomanagement.

Protective role of l-threonine against cadmium toxicity in Saccharomyces cerevisiae.

Environment and food contamination with cadmium (Cd) can cause serious toxicity, posing a severe threat to agricultural production and human health. However, how amino acids contribute to defenses against oxidative stress caused by Cd in cells is not fully understood. As a model eukaryote with a relatively clear genetic background, Saccharomyces cerevisiae has been commonly used in Cd toxicity research. To gain insight into Cd toxicity and cell defenses against it, 20 amino acids were screened for protective roles against Cd stress in S. cerevisiae. The results showed that threonine (Thr, T) had the strongest protective effect against Cd-induced mortality and membrane damage in the cells. Compared to the antioxidant vitamin C (VC), Thr exhibited a higher efficacy in restoring the superoxide dismutase (SOD) activity that was inhibited by Cd but not by H2 O2 in vivo. Thr exhibited evident DPPH (2,2-diphenyl-1-picrylhydrazyl) activity but weak ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-9 sulfonic acid)) scavenging activity, giving it a weaker effect against Cd-induced lipid peroxidation and superoxide radical O2- , compared to VC. More importantly, compared to the chelating agent EDTA, Thr showed stronger chelation of Cd, giving it a stronger protective effect on SOD against Cd than VC in vitro. The results of the in vivo and in vitro experiments revealed that the role Thr plays in cell defenses against Cd may be attributed to its protection of the SOD enzyme, predominantly through the preferential chelation of Cd. Our results provide insights into the protective mechanisms of amino acid Thr that ameliorate Cd toxicityand suggest that a supplement of Thr might help to reduce Cd-induced oxidative damage.

Effects of sublethal Cd, Zn, and mixture exposures on antioxidant defense and oxidative stress parameters in early life stages of the purple sea urchin Strongylocentrotus purpuratus

Oxidative stress parameters were evaluated during the first 72 h of embryonic development of purple sea urchin Strongylocentrotus purpuratus continuously exposed to control conditions, to cadmium alone (Cd, 30 μg/L), to zinc alone (Zn, 9 μg/L) or to a Cd (28 μg/L) plus Zn (9 μg/L) mixture. These sublethal concentrations represent ∼ 10% of the acute EC50. Bioaccumulation, antioxidant capacity against peroxyl radicals (ACAP), total glutathione (GSH) level, glutathione-S-transferase (GST), glucose-6-phosphate dehydrogenase (G6PDH) and superoxide dismutase (SOD) activity, and lipid peroxidation (LPO) were analyzed at 24 h (blastula), 48 h (gastrula), and 72 h (pluteus) stages of development. Zinc (an essential metal) was well-regulated, whereas Cd (non-essential) bioaccumulated and whole-body [Cd] increased from blastula to pluteus stage in sea urchin larvae. In controls, ACAP progressively declined from 24 h to 72 h, while LPO reciprocally increased, but other parameters did not change. Cd alone was more potent than Zn alone as a pro-oxidant, with the major effects being decreases in SOD activity and parallel increases in LPO throughout development; GST activity also increased at 24 h. Zn alone caused only biphasic disturbances of ACAP. In all cases, the simultaneous presence of the other metal prevented the effects, and there was no instance where the oxidative stress response in the presence of the Cd/Zn mixture was greater than in the presence of either Cd or Zn alone. Therefore the sublethal effects of joint exposures were always less than additive or even protective, in agreement with classical toxicity data. Furthermore, our results indicate that SOD and Zn can play important roles in protecting sea urchin embryos against Cd-induced lipid peroxidation.

Alleviation of cadmium-induced genotoxicity and cytotoxicity by calcium chloride in faba bean (Vicia faba L. var. minor) roots.

Alleviation of cadmium-induced root genotoxicity and cytotoxicity by calcium chloride (CaCl2) in faba bean (Vicia faba L. var. minor) seedlings were studied. Faba bean seeds were treated with H2O or 2% CaCl2 for 6h before germination. Seeds were then exposed to 0 and 50µM CdCl2 concentrations for 7days. Genotoxic damaging effects of Cd was examined through the determination of the mitotic index (MI), chromosomal aberrations (CA) and micronucleus (MN) in the meristem cells of faba bean roots. Similarly, effects of Cd stress on metal accumulation, total membrane lipid contents, total fatty acid composition (TFA), lipid peroxidation as indicated by malondialdehyde production, soluble protein and non-protein thiols (NP-SH) contents, hydrogen peroxide production and the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPX) were evaluated after 7days of Cd stress in the seedling roots. Cd stress resulted in the reduction of MI, in addition toMN formation and CA induction in the roots of non-primed seeds (treated with H2O). Moreover, Cd induced lipid peroxidation, H2O2 overproduction and loss of membrane lipid amount and soluble protein content, and changes in the TFA composition in roots of faba bean seedlings. SOD activity declined, but CAT and GPX activities increased. However, seed pre-treatment with CaCl2 attenuated the genotoxic and cytotoxic effects of Cd on Vicia faba roots. The results showed that CaCl2 induced reduction of Cd accumulation, improved cell membrane stability and increased the antioxidant defence systems, thus reducing and alleviating Cd genotoxicity and oxidative damage.

Serratia sp. CP-13 augments the growth of cadmium (Cd)-stressed Linum usitatissimum L. by limited Cd uptake, enhanced nutrient acquisition and antioxidative potential.

The current study was aimed to evaluate the beneficial effects and bioremediation potential of a Cd-tolerant bacterial strain, Serratia sp. CP-13, on the physiological and biochemical functions of Linum usitatissimum L., under Cd stress. The bacterial strain was isolated from the wastewater collection point of Chakera, Faisalabad, Pakistan, as this place contains industrial wastewater of the Faisalabad region. The Serratia sp. CP-13, identified through 16S rRNA gene sequence analysis, exhibited a significant phyto-beneficial potential in terms of invitro inorganic phosphate solubilization, indole-3-acetic acid production and 1-aminocyclopropane-1-carboxylic acid deaminase activity. Effects of Serratia sp. CP-13 inoculation on L. usitatissimum were evaluated by growing the plants in CdCl2 (0, 5 or 10mgkg-1 dry soil)-spiked soil. Without inoculation of Serratia sp. CP-13, Cd stress significantly reduced the plant biomass as well as the quantity of proteins and photosynthetic pigments due to enhanced H2 O2 , malondialdehyde (MDA) contents and impaired nutrient homeostasis. Subsequently, Serratia sp. CP-13 increased the plant fresh and dry biomass, plant antioxidation capacity, whereas it decreased the lipid peroxidation under Cd stress. In parallel, Serratia sp. inoculation assisted the Cd-stressed plants to maintain an optimum level of nutrients (K, Ca, P, Mg, Fe and Mn). The isolated bacterial strain (Serratia sp. CP-13) when applied to Cd-stressed L. usitatissimum inhibited the Cd uptake, reduced Cd-induced lipid peroxidation, maintained the optimum level of nutrients and thereby, enhanced L. usitatissimum growth. The analysis of bio-concentration and translocation factor revealed that L. usitatissimum with Serratia sp. CP-13 inoculation sequestered Cd in plant rhizospheric zone. Serratia sp. CP-13 inoculation is a potential candidate for the development of low Cd-accumulating linseed and could be used for phytostabilization of Cd-contaminated rhizosphere/soil colloids.

Extract from Aronia melanocarpa L. Berries Protects Against Cadmium-induced Lipid Peroxidation and Oxidative Damage to Proteins and DNA in the Liver: A Study using a Rat Model of Environmental Human Exposure to this Xenobiotic.

It was investigated, using a female rat model of low and moderate exposure of human to cadmium (Cd, 1 and 5 mg Cd/kg diet for 3–24 months), whether a polyphenol-rich 0.1% aqueous extract from Aronia melanocarpa L. berries (AE) may prevent Cd-induced lipid peroxidation and oxidative modifications of proteins and deoxyribonucleic acid (DNA) in the liver. For this purpose, markers of lipid peroxidation (lipid peroxides and 8-isoprostane) and oxidative injury of proteins (protein carbonyl groups and 3-nitrotyrosine) and DNA (8-hydroxy-2′-deoxyguanosine) were measured in this organ. The expression of metallothionein 1 (MT1) and metallothionein 2 (MT2) genes was estimated for a better explanation of the possible mechanisms of protective action of AE against Cd hepatotoxicity. The low and moderate treatment with Cd induced lipid peroxidation and oxidatively modified proteins and DNA, as well as enhanced the expression of MT1 and MT2 in the liver, whereas the co-administration of AE completely prevented almost all of these effects. The results allow us to conclude that the consumption of aronia products under exposure to Cd may offer protection against oxidative injury of the main cellular macromolecules in the liver, including especially lipid peroxidation, and in this way prevent damage to this organ.

Different response to Cd stress in domesticated and wild safflower (Carthamus spp.)

Cadmium (Cd) can stress plants by affecting various physiological functions. Cd stress-response mechanisms were investigated in two genotypes of domesticated safflower (Carthamus tinctorius) and a population of wild safflower (Carthamus oxycantous) to explore potential differences in tolerance mechanisms of these species. A hydroponic experiment was conducted with 6-day-old safflower plants. Genotypes AC-Sterling (tolerant) and Saffire (semi-tolerant) from C. tinctorius, and Arak (sensitive) a population from C. oxycantouswere subjected to three concentrations of Cd (i.e., 0, 1, and 20 µM CdCl2). Genotypic differences were detected in Cdtolerance index, Cd concentration in shoots and roots, Cd translocation to shoots, Cd bound to cell walls, superoxide dismutase (SOD) activity, lipid peroxidation, and phytochelatins accumulation in safflower plants upon exposure to CdCl2. Results indicate that genotypic differences were more obvious in the presence of low (i.e., 1 µM) rather than high (i.e., 20 µM) CdCl2 concentrations. Comparing genotypes, root and shoot Cd accumulation was highest in the semi-tolerant genotype. Cadmium translocation to shoots was increased with increasing tolerance. The percentage of Cd bound to root cell walls was higher in the tolerant genotype, but only with low CdCl2 addition. Furthermore, in the tolerant genotype, SOD activity was lowest in both roots and shoots with low CdCl2 addition but highest with high CdCl2 addition, while the opposite was found for phytochelatins. Lipid peroxidation was decreased with Cd tolerance at both CdCl2 concentrations. We conclude that safflower relies mainly on binding Cd to the cell walls and the formation of phytochelatins in root and shoot tissues, in order to handle the Cd stress, evidenced by lessening Cd-induced lipid peroxidation.

Trehalose protects against cadmium-induced cytotoxicity in primary rat proximal tubular cells via inhibiting apoptosis and restoring autophagic flux

Autophagy has an important renoprotective function and we recently found that autophagy inhibition is involved in cadmium (Cd)-induced nephrotoxicity. Here, we aimed to investigate the protective effect of trehalose (Tre), a novel autophagy activator, against Cd-induced cytotoxicity in primary rat proximal tubular (rPT) cells. First, data showed that Tre treatment significantly decreased Cd-induced apoptotic cell death of rPT cells via inhibiting caspase-dependent apoptotic pathway, evidenced by morphological analysis, flow cytometric and immunoblot assays. Also, administration with Tre protected rPT cells against Cd-induced lipid peroxidation. Inhibition of autophagic flux in Cd-exposed rPT cells was markedly restored by Tre administration, demonstrated by immunoblot analysis of autophagy marker proteins and GFP and RFP tandemly tagged LC3 method. Resultantly, Cd-induced autophagosome accumulation was obviously alleviated by Tre treatment. Meanwhile, blockage of autophagosome–lysosome fusion by Cd exposure was noticeably restored by Tre, which promoted the autophagic degradation in Cd-exposed rPT cells. Moreover, Tre treatment markedly recovered Cd-induced lysosomal alkalinization and impairment of lysosomal degradation capacity in rPT cells, demonstrating that Tre has the ability to restore Cd-impaired lysosomal function. Collectively, these findings demonstrate that Tre treatment alleviates Cd-induced cytotoxicity in rPT cells by inhibiting apoptosis and restoring autophagic flux.

Protective Effects of Dietary Garlic Powder Against Cadmium-induced Toxicity in Sea Bass Liver: a Chemical, Biochemical, and Transcriptomic Approach.

To investigate the protective effect of garlic powder on cadmium-induced toxicity sea bass liver, juvenile fishes where maintained under three food diets (diet 1: normal without garlic supply, diet 2: 2% garlic powder; diet 3: 6% garlic powder). After 30days of specific diets, each group was injected with 500μgkg-1of Cd. The control group was the one fed with normal diet and not injected with Cd. Liver Cd, Zn, and Se loads was assessed after 1 and 3days of Cd injections. Moreover, antioxidant enzymes activities termed as catalase, superoxide dismutase, and glutathione peroxydase as well as their gene expression levels were monitored. Finally, metallothionein protein accumulation and its gene expression regulation (MTa) were determined. In fish fed with 2 and 6% garlic powder, the amounts of Cd, Zn, and Se significantly increase in liver tissues. Two percent garlic powder specific diet reversed the Cd-induced inhibition of catalase (CAT), superoxide dismutase (SOD), and gluthathione peroxydase (GPx) and restored the Cd-induced lipid peroxidation (MDA). The increase of liver metallothionein proteins as well as the MTa gene expression level under Cd influence was more pronounced in animals maintained for 30days under garlic power 2% diet. Our data must be carefully considered in view of the garlic powder introduction in sea bass food composition at 2% since it is an efficient prevention against Cd-induced alterations.

Tinospora cordifolia extract attenuates cadmium-induced biochemical and histological alterations in the heart of male Wistar rats

Persistence of cadmium (Cd) in the environment causes serious ecological problems. Tinospora cordifolia is a medicinal herb used in Ayurveda for treating various metabolic disorders and toxic conditions. The present study investigates the protective effect of T. cordifolia stem methanolic extract (TCME) on a heavy metal, Cd-induced cardiotoxicity in male Wistar rats. Male albino Wistar rats were divided into four groups (n=6). The animals after treatment for 28days with Cd and TCME were analysed for biochemical and histological changes in the serum and heart tissues. Cd induced lipid peroxidation and protein carbonylation was significantly reduced by TCME. TCME also reduced the histological alterations induced by Cd treatment in the heart tissues with diminished loss of myocardial fibers. Administration of TCME effectively prevented the altered levels of serum marker enzymes (creatine kinase and lactate dehydrogenase), antioxidants, such as superoxide dismutase, catalase, glutathione, glutathione peroxidase and glutathione-S-transferase, and glycoproteins contents such as hexose, hexoseamine, fucose, and sialic acid by Cd intoxication. TCME also offered protection against the change in levels of Na+K+ATPase, Mg2+ATPase and Ca2+ATPase activities against Cd toxicity. The study suggests TCME as a potent cardioprotective agent against Cd induced toxicity.

Early interconnectivity between metabolic and defense events against oxidative stress induced by cadmium in roots of four citrus rootstocks.

The effect of cadmium on roots of four citrus rootstocks was studied to assess the relationships between oxidative stress, carbohydrates, phenolics and antioxidant responses. Swingle citrumelo (SC), Rangpur lime (RL), Troyer citrange (TC) and Volkamer lemon (VL) genotypes were exposed to 0, 5 and 10µM Cd over 7 days, after which Cd accumulation was markedly higher in roots compared with stems and leaves. Malondialdehyde (MDA) and lipoxygenase (LOX) activity increased in Cd-treated SC and RL roots, suggesting that a lipid peroxidation is the main driver of plasma membrane damage. In contrast, in TC and VL genotypes, LOX-mediated lipid peroxidation does not appear to play a key role in Cd-induced lipid peroxidation, but H2O2 accumulation seems to be responsible of less plasma membrane damage. Catalase (CAT), superoxide dismutase (SOD) and guaiacol and syringaldazine peroxidases (G-POD and S-POD respectively) were differentially affected by Cd. Lipid profile and ATPase-dependant proton extrusion indicated higher disfunctionalities of root plasma membrane in SC and RL genotypes than in TC and VL genotypes. Differences in carbohydrates and phenolic compounds were also observed. Histochemical analysis of G-POD activity and lignin and suberin deposition revealed differences among genotypes. A model to explain the relationships among carbohydrates, soluble phenolics, lipid peroxidation and H2O2 accumulation in Cd-exposed roots was proposed.

Anti-Lipid Peroxidation Activities of Three Selected Fruits Juices Against Cadmium Induced Liver Damage In Vitro

Cadmium (Cd) is one of the most toxic heavy metal. Numerous tissues both in vitro and in vivo suggest that Cd induced lipid peroxidation. The presence of antioxidant can inhbit this process. This present study was designed to determine the effects of mango, papaya, and banana juices on on malondi aldehyde levels (MDA, product of cellular lipid peroxidation) during Cd exposure in vitro. Significant differences was observed between three selected fruits juices and MDA levels and also between concentration of fruits juices and MDA levels. The highest correlation was found between banana juices and MDA levels with IC50 1,12, and followed by papaya and mango juices with IC 50 1,37 and 3,87 respectively. The findings of this study suggest that the three selected fruits juices may exert its protective action against Cd-induced lipid peroxidation in liver homogenate in vitro possibly through its antioxidant mechanism. Key Word Cadmium, Lipid Peroxidation, Antioxidant Activity and Fruits Juices

INVESTIGATION OF THE EFFICACY OF CONCOMITANT ADMINISTRATION OF VITAMIN C, VITAMIN E, OR THEIR COMBINATION IN MODULATING THE DNA DAMAGE AND LIPID PEROXIDATION INDUCED BY CADMIUM IN ALBINO MICE

Cadmium (Cd) is one of the most toxic and industrial pollutant that produces DNA damage and lipid peroxidation due to the formation of reactive oxygen species (ROS). Vitamin C (VC) and vitamin E (VE) are effective antioxidants and free radical scavengers. Therefore, the present study was undertaken to investigate the potential protective role of VC and VE alone or in combination against Cd-induced genotoxicity and lipid peroxidation in mice liver cells. For this purpose, 40 adult male mice were randomly divided into 8 groups (n=5 each). The groups include a control group receiving vehicle, three groups treated with VC (200 mg/kg body weight), VE (200mg/kg body weight), or a combination of VC+VE at the same doses, and a group treated with Cd (2.5 mg/kg body weight) alone. The other three Cd-treated groups receiving concomitant treatment with VC, VE or a combination of VC+VE at the same doses. Comet assay was used as indicator for single strand breaks of DNA and detection of genotoxicity, while determination of malondialdehyde (MDA) concentration was used as indicator for lipid peroxidation. The results showed that co-treatment with VC, VE, or their combination (VC+VE) reduced the DNA damage and lipid peroxidation induced by Cd and the effect of combination (VC+VE) was superior to that of each vitamin alone in reducing the DNA damage and lipid peroxidation. These protective effects may be attributed to their antioxidant activity and scavenging of ROS.

Zn-stimulated mucus secretion in the rainbow trout (Oncorhynchus mykiss) intestine inhibits Cd accumulation and Cd-induced lipid peroxidation

Interest in the interactions between dietary constituents in the gut is increasing, but information remains sparse. In this study rainbow trout were fed non-enriched (186.7±19.0μgZng−1 (dw)), enriched (20% increase) and hyper-enriched Zn (200% increase) diet for 21d followed by a single meal of Cd-spiked food (188.6±9.9μgCdg−1 (dw)). Intestinal, hepatic and renal Zn burdens were measured on Days 7, 14 and 21 and Cd concentrations in the same tissue were measured 48h-post Cd exposure. Oxidative stress was measured as lipid peroxidation in dissected tissues and intestinal mucus was quantified as sialic acid using the thiobarbituric acid assay. Rainbow trout maintained on the hyper-enriched Zn diet experienced significantly increased intestinal mucus secretion (p<0.01), were the only treatment group not to accumulate Cd in the intestine, and there was also no increase in intestinal oxidative damage. Conversely, fish fed the non-enriched and enriched Zn diets did not produce greater than basal levels of intestinal mucus and accumulated significantly greater concentrations of Cd in the intestine (p<0.01) leading to significant localised Cd-induced lipid peroxidation (p<0.01). High levels of mucus production correlated to lower incidences of lipid peroxidation (r2=0.54, p<0.05). These results demonstrate that mucus production stimulated by a high Zn diet have an inhibitory effect on Cd accumulation in the intestine and on Cd-induced lipid peroxidation. Mechanistically, it is likely that the elevated mucus production provides a barrier to Cd uptake. This study describes how one dietary constituent directly modifies the gut environment which indirectly influences the fate of another ingested cation.

The protective effect of grape seed procyanidin extract against cadmium-induced renal oxidative damage in mice

As an important environmental pollutant, cadmium (Cd) can lead to serious renal damage. Grape seed procyanidins extract (GSPE), a biological active component of grape seed, has been shown to possess antioxidative effects. Here, we assessed the protective effect of GSPE on Cd-induced renal damage using animal experiment. After 30 days, the oxidative damage of kidney was evaluated through measurement of superoxide dismutase (SOD), glutathione peroxidation (GSH-Px) and malondialdehyde (MDA). Since, oxidative stress could lead to apoptosis, the renal apoptosis was measured using flow cytometer. Moreover, the expression of apoptosis-related protein Bax and Bcl-2 was analyzed by immunohistochemistry and Western blot. The results showed that Cd led to the decrease of SOD and GSH-Px activities, and the increase of MDA level, induced renal apoptosis. However, the coadministration of GSPE attenuated Cd-induced lipid peroxidation, and antagonized renal apoptosis, probably associated with the expression of Bax and Bcl-2. These data suggested that GSPE has protective effect against renal oxidative damage induced by Cd, which provide a potential natural chemopreventive agent against Cd-poisoning.