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

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

Reducing lead uptake by plants as a way to lead-free food.

In this research, an attempt was made to produce safe food from lead-contaminated soil. It was assumed that an increased amount of calcium (Ca) in plants would prevent them from lead (Pb) uptake. A new-generation agricultural product - an activator of Ca transport in plants "InCa" (from Plant Impact) - was used. The study was conducted on several crop species, Cucumis sativus L., Linum usitatissimum L., Medicago sativa L. and Solanum lycopersicum L., cultivated in mineral medium. The leaves were sprayed with InCa activator while the roots received Pb from the substrate in the form of Pb(NO3)2 dissolved in the medium. It was shown that spraying the leaves with InCa reduced Pb concentration in the roots of S. lycopersicum to 73%, in C. sativus to 60%, and in L. usitatissimum to 57%. Finally, it was found that foliar application of InCa reduced the concentration of Pb in plant roots by 53%, and in plant shoots by 57% (on average by about 55%). These observations were confirmed using histochemical and electron microscopy techniques. It was shown that one of the InCa activator components - Ca(NO3)2 - is responsible for such effects. This result was verified by using another experimental method - the Allium epidermis test. Visualization of Pb in epidermal cells of Allium cepa. L. using the Leadmium™Green fluorescent probe (confocal microscopy) showed a reduction in the amount of Pb that entered the epidermal cells after the application of the tested solutions. For the first time, it was shown that it is possible to reduce Pb uptake by plants by up to 55%. In the future, this offers the possibility of developing a foliar calcium preparation aimed at lowering the concentration of Pb in plants and thereby reducing the amount of Pb in the food chain.

Ameliorative effects of quercetin against hepatic toxicity of oral sub-chronic co-exposure to aluminum oxide nanoparticles and lead-acetate in male rats.

The present study was designed to evaluate the probable ameliorative role of quercetin (QCN) against oxidative hepatotoxicity induced by aluminum oxide nanoparticles (Al2O3NPs) with a diameter < 30 nm and lead acetate (Pb) co-exposure in adult male Sprague-Dawley rats. Rats were weighed and allocated to seven groups (n = 10 each) and were treated orally via orogastric gavage for 60 successive days: rats of the 1st group were kept as control given distilled water (1 ml/kg), rats of the 2nd group received 2 ml/kg BW/day corn oil; rats of the 3rd group were administered 20 mg/kg BW QCN/day; rats of the 4th group received 100 mg/kg BW Al2O3NPs; rats of the 5th group received 50 mg/kg BW Pb; rats of the 6th group co-received Al2O3NPs and Pb at the same previous doses; and rats of the 7th group were co-administered Al2O3NPs, Pb, and QCN at the same previous doses. At the end of the experiment, serum levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total, direct, indirect bilirubin, triglycerides, total cholesterol, HDL, VLDL, and LDL were estimated. The hepatic oxidative stress biomarkers as superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPx), were also evaluated. Finally, the histopathological and histomorphometric evaluations and the residues of Al and Pb in hepatic tissues were assessed. Al2O3NPs and/or Pb exposure significantly elevated lipid peroxidation levels and considerably altered the hepatic biochemical parameters; nevertheless, QCN significantly reduced hepatic enzymes compared to toxicant exposed groups. Additionally, QCN significantly improved Al2O3NPs-afforded liver tissue damage, as established in microscopic findings on the liver in the group treated with Al2O3NPs + Pb. Conclusively, QCN could be a candidate natural agent to safeguard the liver versus the co-harmful impacts of Al2O3NPs and Pb toxicity.

Phytochemical screening, cytotoxicity assessment and evaluation of in vitro antiplasmodial and in vivo antimalarial activities of Mentha spicata L. methanolic leaf extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria causes extensive morbidity and mortality, and the decreasing efficacy of artemisinin and its partner drugs has posed a serious concern. Therefore, it is important to identify new antimalarials, and the natural compounds from plants provide a promising platform. Mentha spicata L. representing the Lamiaceae family has been used in traditional medicine for various diseases including malaria. AIM OF THE STUDY: This study was aimed at evaluating the antiplasmodial activity of M. spicata methanolic leaf extract using Plasmodium falciparum (Pf) cultures (Pf3D7 and artemisinin (ART)-resistant PfCam3.IR539T strains) and antimalarial activity using Plasmodium berghei (Pb)-infected mice. Dry leaf powder and methanolic leaf extract were examined for in vivo antimalarial activity and the efficacy of oral versus parenteral administration was compared. MATERIALS AND METHODS: Leaves of M. spicata were collected and extracted using 70% methanol in water (v/v). [3H]-hypoxanthine incorporation assays and Giemsa-stained smears were used to assess the in vitro antiplasmodial activity of M. spicata methanolic extract against Pf3D7 and ART-resistant PfCam3.IR539T strains. Cytotoxicity was evaluated in HeLa and HEK-293T cell lines using MTT assays. Hemolysis assays were performed using red blood cells (RBCs). In vivo antimalarial activities of M. spicata dry leaf powder and methanolic leaf extract were examined in P. berghei-infected mice by Rane's curative test and Peters' 4-day suppressive test. RESULTS: Phytochemical screening of M. spicata methanolic leaf extract indicated the presence of reducing sugars, phenolic compounds, flavonoids, glycosides, sterols, saponins, alkaloids, coumarins, tannins, carbohydrates, and proteins. In vitro studies carried out using Pf cultures showed that M. spicata methanolic leaf extract had significant antiplasmodial activity against Pf3D7 cultures with a 50% inhibitory concentration (IC50) of 57.99 ± 2.82 µg/ml. The extract was also effective against ART-resistant PfCam3.IR539T strain with an IC50 of 71.23 ± 3.85 µg/ml. The extract did not show significant in vitro cytotoxicity, hemolysis, and in vivo toxicity. In vivo studies performed using Pb-infected mice treated with M. spicata dry leaf powder and methanolic leaf extract showed ∼50% inhibition in parasite growth at 1500 mg/kg and 1000 mg/kg doses, respectively. There was also a significant delay in the mortality of treated mice. Parenteral administration was found to be appropriate for the in vivo treatment. CONCLUSIONS: Our in vitro and in vivo findings from Pf and Pb parasites suggested the therapeutic potential of M. spicata leaf extract as an antimalarial. M. spicata leaf extract could also inhibit the growth of ART-resistant Pf strain. Further studies on fractionation and active component analysis of M. spicata leaf extract would be required to identify the bioactive phytochemicals having pharmaceutical and therapeutic values. Such efforts would help us in developing new antimalarials to combat malaria.

Tissue Heavy Metals in Liver Diseases.

BACKGROUND: Our objective was to determine the levels of heavy metals, oxidants, and antioxidants in liver tissue of patients with chronic liver disease (CLD) compared with healthy living liver donors (LLDs). METHODS: We obtained liver specimens from patients undergoing liver transplant for CLD. Samples were also obtained from LLDs. Biochemical analyses were performed on all samples, and the levels of liver tissue, heavy metal, and oxidant-antioxidants biomarker levels in patients with CLD were compared with those measured in LLDs. RESULTS: One hundred and eighteen individuals were included for analyses. Fifty-nine were patients with CLD, and 59 were LLDs. The median levels of liver tissue of superoxide dismutase (P = .009), glutathione peroxidase (P = .042), total oxidant status (P = .006), oxidative stress index (P < .001), and copper (P = .035) were prominently more elevated in CLD than LLDs. On the other hand, the median levels of liver tissue of cadmium (P < .001), selenium (P = .042), and zinc (P < .001) levels were more elevated in the LLDs than patients with CLD. The 2 groups were similar in terms of total antioxidant status, manganese, arsenic, and lead levels. CONCLUSIONS: Superoxide accumulation in the liver was higher in patients with CLD. Concerning heavy metals, only the median tissue copper was elevated in patients with CLD with higher Cu/Zn ratio. Cadmium, selenium, and zinc were significantly higher in the healthy LLDs.

Gender differences in trace element exposures with cognitive abilities of school-aged children: a cohort study in Wujiang city, China.

Trace elements persist in the environment, and their early exposure may adversely affect children's intellectual development. To clarify the influence of blood trace element levels in newborns and school-aged children, we used Wechsler Intelligence Scale for children (WISC-CR) to explore intellectual development level of 148 school-aged children based on a population cohort study. Lead (Pb), selenium (Se), arsenic (As), copper (Cu), manganese (Mn) and chromium (Cr) in cord blood and Pb, As, Cu in venous blood were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometer (AAS). Our analysis of the correlation between children's mental development and trace element content found children's cognitive abilities negatively correlate with Pb (PIQ: ß=-0.109, P=0.03737) and Cu (PIQ: ß=-0.031, P=0.04431; FISQ: ß=-0.031, P=0.02137) levels in cord blood. Prenatal low-level As exposure may negatively affect girls' performance intelligence quotient (PIQ) and verbal intelligence quotient (VIQ). There were differences in Se levels in cord blood and venous blood between boys and girls (P=0.010; P=0.073). High Se levels were associated with a lower VIQ in boys and a higher VIQ in girls. Prenatal exposure to Pb, As and Cu may weaken children's cognitive abilities at school age. Se exposure may have opposite effects on cognitive abilities affected by dose and gender.

Ginkgo biloba Supplement Reverses Lead (II) Acetate-Induced Haematological Imbalances, Hepatic and Renal Dysfunctions in Male Wistar Rat.

Lead is a heavy metal abundant in nature that causes haematological imbalances, and hepatic and renal dysfunction, and this imbalance has been linked to oxidative stress. Several reports have shown that natural products are implicated in ameliorating metal poisonings. Ginkgo biloba is a flavonoid-rich natural herbal supplement with several pharmacological properties. The present study investigated effect of Ginkgo biloba supplement (GBS) on lead-induced toxicity. Animals were given a lead dose of 25 mg/kg for 14 days orally and then given Ginkgo biloba supplements of 50 mg/kg and 100 mg/kg orally for 14 days. Animals given GBS had significantly improved haematological and rheological parameters. GBS showed a protective impact in terms of improved kidney and liver histology, anti-oxidant enzyme activity (CAT, SOD, GSH, and MDA), organ function indices, and a lower rate of erythrocyte osmotic fragility. Conclusively, Ginkgo biloba supplementation attenuated lead toxicity by normalization of haematological imbalances, and hepatic and renal dysfunction as well as maintaining erythrocyte membrane integrity.

Hepatorenal Protective Effect of Fenugreek Aqueous Extract against Lead Toxicity in Experimental Rats.

In this study, aqueous extract of germinated fenugreek seeds was investigated to assess its therapeutic effect on hepatorenal lead toxicity in experimental rats. After overnight fasting, rats were injected intraperitoneally with 0.5 mL of lead acetate at a dose of 35 mg/kg body weight for five consecutive days. Animals were divided into four groups of ten rats each: normal control; untreated negative control and rats treated with 200 or 400 mg/kg body weight of the aqueous extract. Treatments were performed by intraperitoneal injection of 1mL of the extract once a day for 28 consecutive days. Results showed significant differences between treated and control groups during the whole period of the experiment. This was demonstrated by improving body weight and level of serum total protein, decreasing levels of serum ALT, AST, total bilirubin, blood urea nitrogen, and creatinine. As well, histological analysis revealed a marked reduction in inflammation and structural alterations of liver and kidney organs of fenugreek-treated rats. This hepatoprotective effect can be attributed to the anti-inflammatory, anti-oxidant and regenerative capacity of the high content of the phytochemical constituents in the extract.

A Comparison of the Effect of Lead (Pb) on the Slow Vacuolar (SV) and Fast Vacuolar (FV) Channels in Red Beet (Beta vulgaris L.) Taproot Vacuoles.

Little is known about the effect of lead on the activity of the vacuolar K+ channels. Here, the patch-clamp technique was used to compare the impact of lead (PbCl2) on the slow-activating (SV) and fast-activating (FV) vacuolar channels. It was revealed that, under symmetrical 100-mM K+, the macroscopic currents of the SV channels exhibited a typical slow activation and a strong outward rectification of the steady-state currents, while the macroscopic currents of the FV channels displayed instantaneous currents, which, at the positive potentials, were about three-fold greater compared to the one at the negative potentials. When PbCl2 was added to the bath solution at a final concentration of 100 µM, it decreased the macroscopic outward currents of both channels but did not change the inward currents. The single-channel recordings demonstrated that cytosolic lead causes this macroscopic effect by a decrease of the single-channel conductance and decreases the channel open probability. We propose that cytosolic lead reduces the current flowing through the SV and FV channels, which causes a decrease of the K+ fluxes from the cytosol to the vacuole. This finding may, at least in part, explain the mechanism by which cytosolic Pb2+ reduces the growth of plant cells.

Soil cadmium and lead affecting biochemical properties of Matricaria chamomilla L. at different growth stages in the greenhouse and field.

Heavy metals bioremediation by medicinal plants is an important research issue, which has yet to be investigated. Matricaria chamomilla accumulation of soil cadmium (Cd, 0, 10 and 40 mg/kg) and lead (Pb, 0, 60 and 180 mg/kg) affecting plant biochemical properties L. at different growth stages in the greenhouse and field was investigated. The 10-kg experimental pots (located in the greenhouse and field with 80% of field capacity moisture) were filled with the treated soils, and were planted with M. chamomilla L. seeds (three replicates). Plants were sampled to determine their biochemical properties including Cd and Pb contents, pigments, proline (Pro), leaf relative water (LRW), lipid peroxidation (LX), and superoxide dismutase (SOD, EC 1.15. 1.1), and catalase (CAT, EC 1.11.1.6) activities. Soil final concentration of Cd and Pb was also determined. Heavy metal stress significantly decreased plant pigment contents; however, it significantly increased plant PRO, LRW, LX and SOD, and not CAT. Heavy metal, growth stage, growth location, and their interactions significantly affected plant heavy metal concentrations. Interestingly, although significantly higher concentration of Cd was observed in plant aerial part under greenhouse conditions, plant roots had significantly higher concentrations of Cd under field conditions, and it was reverse for Pb. Increased concentration of Cd and Pb significantly enhanced plant Pro content and the highest one was resulted by Pb3 (913.46 mg/g fresh weight) significantly higher than other treatments including Cd3 (595.34 mg/g fresh weight). M. chamomilla is a suitable species for the bioremediation of soils polluted with Cd and Pb.

Rare cases of severe life-threatening lead poisoning due to accident or chronic occupational exposure to lead and manganese: Diagnosis, treatment, and prognosis.

BACKGROUND: Chronic long-term, low-dose environmental and occupational exposure to lead (Pb) has been extensively studied in large cohorts worldwide among general populations, miners, smelters, or battery workers. However, studies on severe life-threatening Pb poisoning due to accidental or chronic occupational exposure to Pb and manganese (Mn) were rarely reported. METHODS: We present one case of acute severe Pb poisoning and compare it with another severe chronic occupational exposure case involving Pb and Mn. A 27-year-old woman mistakenly took a large quantity of pure Pb powder as an herbal remedy; she developed abdominal colic, severe nausea, vomiting, fatigue, and cutaneous and sclera icterus. Laboratory tests showed her blood lead level (BLL) of 173.5 µg dL-1 and urinary lead level (ULL) of 1240 µg dL-1. The patient was diagnosed with acute Pb poisoning and acute liver failure. In another chronic exposure case, a 56-year-old man worked in a Pb and Mn smelting factory for 15 years. He was brought to the emergency room with severe nausea, vomiting, and paroxysmal abdominal colic, which was intolerable during the onset of pain. His BLL was 64.8 µg dL-1 and ULL was 38 µg dL-1, but his blood and urinary Mn levels were normal. The patient was diagnosed with chronic Pb poisoning. Both patients received chelation therapy with calcium disodium ethylene-diamine-tetraacetate (CaNa2EDTA). The woman with acute severe Pb intoxication recovered well and was discharged from the hospital after treatment, and the man who survived severe Pb poisoning was diagnosed with lung cancer. CONCLUSION: Clinical manifestations of acute and chronic severe Pb poisoning are different. Chelation therapy with CaNa2EDTA is proven to be an effective life-saving therapy in both cases by reducing BLL. Occupational exposure to both Pb and Mn does not appear to increase Mn neurotoxicity; however, the probability that co-exposure to Mn may increase Pb toxicity in the same patient cannot be excluded.

Identification of new promising plant-based lead compounds for inhibition of prokaryotic replicative DNA polymerases: combination of in silico and in vitro studies.

Emerging widespread bacterial resistance to current antibiotics with traditional targets is one of the major global concerns. Therefore, so many investigations are exploring the potential of other druggable macromolecules of bacteria such as replication machinery components that are not addressed by previous antibiotics. DNA polymerase is the major part of this machine. However, a few studies have been done on it so far. In this respect, we report the discovery of four new plant-based leads against DNA polymerase (pol) IIIC (three leads) and pol IIIE (one lead) of Gram-positive and negative bacteria by combining a sequentially constrained high-throughput virtual screenings on Traditional Chinese Medicine Database with in vitro assays. The compounds displayed relatively good levels of inhibitory effect. They were active against their designated targets at micromolar concentrations. The IC50 values for them are ranged from 25 to 111 µM. In addition, they showed minimum inhibitory concentrations in the range of 8-128 µg/mL against five representatives of pathogenic bacteria species. However, they were inactive against Pseudomonas aeruginosa. Given these results, these leads hold promise for future modification and optimization to be more effective in lower concentrations and also against most of the important bacterial species. Communicated by Ramaswamy H. Sarma.

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

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

Enhanced Internalization of Indian Ayurvedic Swarna Bhasma (Gold Nanopowder) for Effective Interaction with Human Cells.

In the ancient traditional Indian Ayurvedic system of natural healing, gold nanoparticles (Swarna Bhasma, gold ash) have been used for its therapeutic benefits as far back as 2500 B.C. Ayurvedic medicinal preparations are complex mixtures that include many plant-derived products and metals. Bhasmas date as far back as the 8th century and are made by samskaras (processings), such as shodhana (purification and potentiation), jarana (roasting), and marana (incineration, trituration) in the presence of plant products, including juices and concoctions. Previous studies characterized the physical properties of gold ash, and the mechanisms of its entry into human cells, but only preliminary data exist on its toxicity. Before using nanoparticles for therapeutic application, it is extremely important to study their toxicity and cellular internalization. In the present study, various imaging techniques were used to investigate Swarna Bhasma's (gold nanopowder) toxicity in both cancerous and noncancerous cells (HeLa and HFF-1) and to characterize its spectral properties. The results showed that gold ash particles had no impact on the cellular viability of both HeLa and HFF-1 cells, even at high concentrations or long incubation times. Moreover, it was found that the internalization level of Swarna Bhasma to cells may be improved by mechanical breaking of the large aggregates into smaller agglomerates. Hyperspectral images revealed that after breaking, the small agglomerates have different spectral properties in cells, compared to the original aggregates, suggesting that size of particles is instrumental for the subcellular interaction with human cells.

Characterization and Antimicrobial Property of Some Heavy Metals Containing Ayurvedic Drugs.

Ayurvedic medicines are often used in different formulations, the heavy metals, which are generally referred to as being toxic. In this work, we report on the physicochemical characterization and biological activity of some typical Ayurvedic drugs available in the market that contain arsenic, mercury and lead with the emphasis on their antibacterial performance. Among the formulations studied, some of the drugs with 'amorphous' texture (and higher solubility) were found quite active against some bacterial strains whereas the formulations possessing crystalline texture (and low solubility) were found practically ineffective. The moderate activity of some drugs against Gram-negative bacteria fairly suggested the presence of the small-sized polar molecules which was also supported by the FTIR spectroscopic data.

Effect of Dietary Zinc-Nanoparticles on Growth Performance, Anti-Oxidative and Immunological Status of Fish Reared Under Multiple Stressors.

Zinc is one of the essential micronutrients that can be obtained via water and diet in aquatic animals to meet their physiological needs. The present study was designed to understand the effect of the supplementation of zinc nanoparticles (Zn-NPs) in mitigating abiotic and biotic stress in Pangasius hypophthalmus. Two zinc nanoparticle-incorporated diets with 10 and 20 mg/kg nanoparticles and a control without zinc nanoparticles were formulated. To study the effect of formulated feeds on stress tolerance, fish were exposed to sublethal dose (4 ppm) of Pb (lead) and temperature at 34 °C. Two hundred and seventy-three fish were randomly distributed into seven treatment groups in triplicates, namely a control group (no Zn-NPs and no Pb and temperature exposure, Ctr/Ctr), control diet fed and exposed to Pb (Ctr/Pb), control diet fed and concurrently exposed to Pb and temperature (Pb-T/Ctr), and Zn-NPs 10 and 20 mg/kg diet with or without stressors (Zn-NPs 10 mg/kg, Zn-NPs 20 mg/kg, Pb-T/Zn-NPs 10 mg/kg, Pb-T/Zn-NPs 20 mg/kg). The effect of Zn-NPs on growth performance, stress biomarkers, biochemical and immunological responses, and survival of P. hypophthalmus following challenge with pathogenic bacteria were evaluated. The growth performance was noticeably (p < 0.01) enhanced, and anti-oxidative stress (catalase, superoxide dismutase, and glutathione-s-transferase) significantly reduced in the Zn-NPs supplemented groups. Similarly, immunological parameters such as total protein, albumin, globulin, and A/G ratio significantly improved, and stress biomarkers such as blood glucose, cortisol, and HSP 70 were reduced in Zn-NPs supplemented groups. Overall, the results suggest that supplementation of dietary Zn-NPs with less concentration in the diet has a definitive role in the mitigation of abiotic and biotic stress in P. hypophthalmus.

Selenium Antagonizes the Lead-Induced Apoptosis of Chicken Splenic Lymphocytes In Vitro by Activating the PI3K/Akt Pathway.

Lead (Pb) pollution has become one of the most serious global ecological problems. In animals, Pb ingestion induces apoptosis in many tissues. However, the mechanisms by which Pb induces apoptosis in chicken splenic lymphocytes in vitro via the PI3K/Akt pathway and the antagonistic effect of selenium (Se) on Pb remain unclear. Therefore, we established the in vitro Se-Pb interaction model in chicken splenic lymphocytes and examined the frequency of apoptotic cells using acridine orange/ethidium bromide (AO/EB) staining and the TdT-mediated dUTP nick end labeling assay and detected the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT), as well as the levels of malondialdehyde (MDA) and reactive oxygen species (ROS). The expression of PI3K/Akt pathway-related genes was also examined by qRT-PCR and western blotting. MDA and ROS levels were markedly increased, whereas the activities of GPx, SOD, and CAT were significantly decreased; the levels of the PI3K, Akt, and Bcl-2 messenger RNAs (mRNAs) and proteins were decreased; and the levels of the p53, Bax, cytochrome c (Cyt-c), caspase 3, and caspase 9 mRNAs and proteins were increased in the Pb group. In addition, the frequency of apoptotic cells was also significantly increased by the Pb treatment. However, Se supplementation during Pb exposure observably attenuated Pb-induced apoptosis; increased the levels of the PI3K, Akt, and Bcl-2 mRNAs and proteins; and decrease the levels of the p53, Bax, Cyt-c, caspase 3, and caspase 9 mRNAs and proteins in the chicken spleen. In conclusion, Pb exposure causes oxidative stress, inhibits the PI3K/Akt pathway, and subsequently induces apoptosis in chicken splenic lymphocytes in vitro, and these effects are partially attenuated by Se supplementation. To the best of our knowledge, this study is the first to reveal the antagonistic effect of Se on Pb-induced apoptosis of chicken splenic lymphocytes in vitro via the activation of the PI3K/Akt pathway.

The Antagonistic Effect of Selenium on Lead-Induced Immune Dysfunction via Recovery of Cytokine and Heat Shock Protein Expression in Chicken Neutrophils.

Lead (Pb) is a ubiquitous and toxic heavy metal and it can damage the immune system in humans and animals. Many researchers have reported that Selenium (Se) could possess various pharmacological effects in mammals. However, few studies have been carried out to investigate the protective role of Se in birds, especially in chickens. In this study, we investigated the protective effects of Se against Pb-induced inflammatory responses and the expression of heat shock proteins (HSPs) in peripheral blood neutrophils. One hundred eighty Hy-Line brown chickens were randomly divided into the control group (Con group), Se supplementation group (+Se group), Pb supplementation group (+Pb group), and the Se and Pb compound group (Se+Pb group). On the 90th day of the experiment, the peripheral blood was collected to extract neutrophils, and then, the levels of HSPs and cytokines were examined. The results showed that, after Pb treatment, the levels of IL-(1ß, 1R, 4, 8, 10, and 12ß), TGF-ß4, and HSP (27, 40, 60, 70, and 90) mRNA were significantly increased and levels of IL-2 and IFN-γ mRNA were decreased compared with those in the control group. Compared with the control group, the protein levels of HSP60 and HSP70 were also increased in the Pb treatment group. Co-administration of Se (1 mg/kg/day) and Pb resulted in a reversal of the Pb-induced cytokine changes in neutrophils accompanied by a significant decrease in HSPs. Our study demonstrated that Pb could decrease the immune function via changing the expression of cytokines and HSPs in chicken neutrophils, but Se could relieve the toxic effect induced by Pb.

Antagonistic effects of selenium on lead-induced autophagy by influencing mitochondrial dynamics in the spleen of chickens.

Lead (Pb) may damage the immune function in human and animal. Selenium (Se) has antagonistic effects on Pb. In our study, brown layer chickens were randomly allocated to control group, Se group (1 mg/kg Se), Se+Pb group (1 mg/kg Se and 350 mg/kg Pb), and Pb group (350 mg/kg Pb). The chickens were sacrificed on the 90th day; spleen tissues were subjected to observation of ultrastructure and detection of spleen-related indexes. The results revealed that in the Pb group, expression levels of the cytokines IL-1 and TNF-α significantly increased, and expression levels of IL-2 and INF-γ significantly decreased; activities of antioxidant enzyme GPX, SOD and CAT significantly decreased, and expression level of malondialdehyde (MDA) significantly increased; expression levels of mitochondrial fission-related genes (Mff and Drp1) significantly increased, and expression levels of mitochondrial fusion-related genes (Opa1, Mfn1 and Mfn2) significantly decreased; expression of autophagy-related genes (Beclin 1, Dynein, Atg 5, LC3-I and LC-II) was upregulated, while expression of mammalian target of rapamycin (mTOR) was downregulated. The results of transmission electron microscopy indicated that Pb induced mitochondrial fragmentation, and triggered autophagy in the spleen of chickens. The Se and Pb co-treatment remarkably alleviated these injuries induced by Pb in the spleen of chickens. In conclusion, Pb can induce the oxidative stress to influence the mitochondrial dynamics balance and lead to autophagy, which triggers the immune dysfunction in the spleen of chickens; the Se exhibits the antagonistic effects on lead-induced autophagy by influencing mitochondrial dynamics in the spleen of chickens.

Purification and functional properties of a novel glucoamylase activated by manganese and lead produced by Aspergillus japonicus.

Microbial amylases are used to produce ethanol, glucose and can be applied in textiles products, detergents and other industries. This study aimed to determine the best carbon source concentration to induce the amylase production by A. japonicus, and its purification and biochemical characterization. For that, this fungus was cultivated in Khanna medium, pH 5.5, for 4 days, at 25°C, in static condition, supplemented with potato starch and maltose in different concentrations. The fungal crude enzymatic extract was purified in a unique elution in DEAE-cellulose column and the molecular mass was determined as 72kDa. The optimum temperature and pH was 65°C and 5.0, respectively. Amylase remained 75% of its activity after one hour at 50°C and was stable in the pH range 3.0-7.0. The analysis of the end-products by thin layer chromatography showed only glucose formation, which characterizes the purified enzyme as a glucoamylase. Amylopectin was the best substrate for the enzyme assay and Mn+2 and Pb+2 were good glucoamylase activators. This activation, in addition to the biochemical characteristics are important results for future biotechnological applications of this glucoamylase in the recycling and deinking process by the paper industries.