Metaphire guillelmi exhibited predominant capacity of arsenic efflux.

Earthworm could regulate their body concentration of arsenic via storage or excretion, and the ability of As efflux among different earthworms is not consistent. Here, whole and semi As exposure patterns with 0-10-30-60-100 mg kg-1 exposure concentrations were set to characterize the As efflux in geophagous earthworm, Metaphire guillelmi. Cast As (As-C) and earthworms' antioxidative responses were monitored to explore the efflux mechanisms under 30 mg kg-1 As-spiked soil (As30), besides, As concentration in earthworm tissue after egestion and dissection depurations were compared. In the whole exposure pattern, As concentration in gut content (As-G, 19.2-120.3 mg kg-1) surpassed that in the tissue (As-T, 17.2-53.2 mg kg-1), and they both increased with exposure concentrations. With the prolong time, they firstly increased and kept stable between day 10-15, then As-G increased while As-T decreased between day 15-20. In the semi-exposure pattern, both As-G and As-T decreased when M. guillelmi was transferred to clean soil for 5 days. During the 42-day incubation in As30, the antioxidative responses including reactive oxygen species (ROS), glutathione (GSH) and glutathione-S-transferase (GST) were firstly increased and then decreased, and As-C (13.9-43.9 mg kg-1) kept higher than As-G (14.2-35.1 mg kg-1). Significantly positive correlations were found between As-T and GSH, As-C and GST. Moreover, tissue As after dissection (11.6-22.9 mg kg-1) was obviously lower than that after egestion (11.4-26.4 mg kg-1), but significantly related to ROS and GSH. Taken together, M. guillelmi exhibited excellent capacity of As efflux, and GSH explained tissue As accumulation while GST facilitated the As elimination via cast. Besides, dissection instead of egestion revealed the As efflux in M. guillelmi more accurately. These findings contributed to a better understanding of how geophagous earthworm M. guillelmi regulated tissue As accumulation for As stress tolerance, and recommended an optimal depuration mode to characterize As accumulation.

Effect of lead ions on biochemical behavior of Cladophora glomerata in sterilized and non-sterilized media.

Freshwater ecosystems are under peril globally due to anthropogenic influences, most notably metals. The present study aimed to evaluate the morphological and biochemical responses of Cladophora glomerata obtained from a freshwater stream to various lead concentrations (0.0, 7.5, 15, 30, and 60 mg/L Pb2+) in sterilized and non-sterilized media. Pigments, proline, malondialdehyde (MDA), total phenolic compounds (TPC), hydrogen peroxide, and protein content of the green alga were determined in response to various growing conditions. Pb2+ stress had a detrimental effect not only on biochemical components of C. glomerata but also on the algal cell's shape and surface structure. High Pb2+ concentrations significantly decreased chlorophyll-a (from 1350 µg/g in non-sterilized and 1340 µg/g in sterilized media for the control group to 1067 µg/g in non-sterilized and 1049 µg/g in sterile media at 60 mg/L Pb2+) and protein contents (from 34.47 mg/g for the sterilized and 35.89 mg/g for non-sterilized of the control to 24.82 mg/g for the sterilized and 26.18 mg/g for the non-sterilized at 60 mg/L Pb2+) of algal biomass but increased the concentrations of stress compounds (e.g., MDA, proline, and TPC). Variation in the macroalgal biomass composition was also indicated by FTIR analysis based on interactions between amino, amide, and anionic surface groups on the algal biomass and Pb2+ ions. Morphological and biochemical responses of C. glomerata reveal that non-sterile conditions encouraged the proliferation of this macroalga under Pb2+ exposure.

Dinoflagellate Karenia mikimotoi on the growth performance, antioxidative responses, and physiological activities of the rotifer Brachionus plicatilis.

The harmful dinoflagellate Karenia mikimotoi is responsible for the mortality of aquatic animals. However, the mechanism behind these toxic effects has not been fully determined. Herein, the toxic effects of K. mikimotoi on the growth performance, antioxidative responses, physiological activities, and energetic substance contents of rotifer Brachionus plicatilis were assessed. Rotifers were exposed to Nannochloropsis salina (Eustigmatophyceae), K. mikimotoi, and a mixture of N. salina and K. mikimotoi with biomass ratio proportions of 3:1, 1:1, and 1:3, respectively. Results indicated that K. mikimotoi negatively affected the population growth, survival, and specific growth rates of rotifers within 24 h. The level of reactive oxygen species (ROS), the content of malondialdehyde, and the activity of amylase increased. However, the total antioxidant capacity level, pepsase, cellulase, alkaline phosphatase, xanthine oxidase, and lactate dehydrogenase activities, and glycogen and protein contents decreased with increasing proportions of K. mikimotoi. The mixture of 50% N. salina and 50% K. mikimotoi promoted the increase in glutamic-pyruvic transaminase activity and triglyceride content. These findings underscore ROS-mediated antioxidative responses, physiological responses, and energetic substance content changes in B. plicatilis work together to affect population dynamics inhibition of rotifers by K. mikimotoi.

Changes in physiological activities are responsible for homoyessotoxin-induced toxicity in abalone Haliotis discus hannai.

Homoyessotoxin (homo-YTX) is a lipid-soluble toxin produced by toxic dinoflagellates. It is widely distributed in marine ecosystems worldwide, and it poses a threat to the survival of aquatic animals. The tissues of the abalone Haliotis discus hannai are easily damaged by homo-YTX during harmful algal blooms. In this study, H. discus hannai was exposed to homo-YTX (0, 2, 5, and 10 µg L-1) to evaluate the rates of survival (S) and death (D) and the antioxidative, metabolic, and digestive physiological responses in the gills and digestive gland of abalone. Homo-YTX decreased S and the activities of Na+/K+-adenosine triphosphatase, Ca2+/Mg2+-adenosine triphosphatase, superoxide dismutase, catalase, alkaline phosphatase, xanthine oxidase, lactate dehydrogenase, amylase, protease, and lipase. Meanwhile, D, the reactive oxygen species level, and the malondialdehyde content increased with increasing concentrations of homo-YTX. In addition, homo-YTX induced oxidative stress, enhanced the lipid peroxidation reaction, reduced the energy supply, and inhibited the metabolic and digestive physiological activities in the gills and digestive gland of abalone. Oxidative stress-mediated insufficient energy supply and physiological activity reduction caused the death of abalone.

Abnormal chilling injury of postharvest papaya is associated with the antioxidant response.

Generally, the lower the temperature and/or the longer the duration of low temperature, the more serious chilling injury (CI) symptom appears in fruit. However, our previous study showed that the higher storage temperature (6°C) resulted in a more serious CI in papaya fruit compared to that stored at 1°C, which could be viewed as an abnormal CI behavior. This study investigated the antioxidant responses that existed in abnormal CI behavior of papaya fruit. Compared to 6°C, antioxidant enzyme activities of papaya fruit which was stored at 1°C were maintained at a higher level while the circulatory metabolism of the ascorbate-glutathione cycle (AsA-GSH) was more vigorous in papaya fruit, as indicated by higher superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) activities and higher AsA and GSH levels, which could reduce the superoxide anion (·O2 - ) production rate and the hydrogen peroxide (H2 O2 ) content. Suppressed reactive oxygen species (ROS) generation in papaya fruit at 1°C resulted in reduced membrane permeability and malondialdehyde (MDA) accumulation when compared to that at 6°C, thus the development of CI was restricted during storage at 1°C. This study deepened the understanding of differential antioxidant responses during cold storage at 1°C and 6°C in papaya fruit and provided a theoretical basis for further study on the mechanism of the abnormal CI behavior in papaya fruit. PRACTICAL APPLICATIONS: Low-temperature storage is one of the most effective methods to preserve fruit and vegetable products. While, inappropriate low temperature could induce CI, and the damage caused by CI is often more serious than estimated. Therefore, it is necessary to study the physiological and biochemical characteristics of different postharvest fruits and vegetables to prolong storage period, improve storage quality and reduce the loss of products. This study analyzed the antioxidant reaction in abnormal CI behavior of papaya, which could contribute to the further study on the mechanism of CI in papaya fruit and provide theoretical basis for the development of preservation technology of papaya fruit.

Application of abscisic acid and 6-benzylaminopurine modulated morpho-physiological and antioxidative defense responses of tomato (Solanum lycopersicum L.) by minimizing cobalt uptake.

A hydroponic study was conducted to determine the effects of single and/or combined application of different doses (0, 5 and 10 µM L-1) of abscisic acid (ABA) and 6-benzylaminopurine (BAP) on cobalt (Co) accumulation, morpho-physiological and antioxidative defense attributes of tomato (Solanum lycopersicum L.) exposed to severe Co stress (400 µM L-1). The single Co treatment (T1), prominently decreased tomato growth, relative water contents, photosynthetic pigments (chlorophyll a and chlorophyll b), whereas enhanced oxidative stress and Co accumulation in shoot and root tissues. Nonetheless, the supplementation of ABA and 6-BAP via nutrient media significantly (P < 0.05) enhanced plant biomass, root morphology and chlorophyll contents of tomato, compared to only Co treatment (T1). Moreover, the oxidative stress indicators such as malondialdehyde, proline and H2O2 contents were ameliorated through activation of enzymatic antioxidant activities i.e. ascorbate peroxidase, superoxide dismutase, catalase, and peroxidase, in growth modulator treatments in comparison to T1. The Co uptake, translocation (TF) and bioaccumulation factor (BAF) by shoot and root tissues of tomato were significantly reduced under all the treatments than that of T1. The supply of 6-BAP alone or in combination with ABA at 10 µM L-1 application (T7) rate was found the most effective to reduce Co accumulation in the roots and shoots by 48.4% and 70.2% respectively than T1 treatment. It can be concluded that two plant growth modulators could improve the stress tolerance by inhibition of Co uptake in tomato plants.

Effects of fucoidan on the hematic indicators and antioxidative responses of Nile tilapia (Oreochromis niloticus) fed diets contaminated with aflatoxin B1.

Fucoidan is a rich source of medicinally active immunostimulants that possess various pharmacological properties. This study examined the potential impact of fucoidan on the hematic indicators and antioxidative responses of Nile tilapia fed diets contaminated with aflatoxin B1 (AFB1). Fish (60 ± 6.1 g) were allocated to five groups; the first (control) and second groups were fed 0% or 1% fucoidan-supplemented diets without AFB1 contamination, while the third, fourth, and fifth groups were fed diets contaminated with AFB1 and supplemented with 0%, 0.5%, and 1% fucoidan, respectively. After 30 days, fish fed AFB1 showed high ALT, AST, ALP, cholesterol, urea, and creatinine levels; furthermore, total blood protein and tissue (liver, kidney, and gill) glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activity significantly (P ≤ 0.05) decreased in fish fed AFB1, while tissue malondialdehyde significantly increased (P ≤ 0.05). Interestingly, fish fed fucoidan showed decreased ALT, AST, ALP, cholesterol, urea, and creatinine, as well as increased blood protein, GSH, GPx, SOD, and CAT activity. The results suggested that fucoidan is capable of inducing protective activity against AFB1 toxicity in Nile tilapia by enhancing the serum biochemical and tissue antioxidant responses of fish.

Exposure of tomato (Lycopersicon esculentum) to silver nanoparticles and silver nitrate: physiological and molecular response.

Silver nanoparticles (AgNPs) are among the most widely used nanomaterials, with applications in sectors as diverse as communications, energy, medicine, and agriculture. This diverse application of AgNPs increases the risk of the release of these materials into the environment and raises the potential for transfer into plants and, subsequently, the human body. To better understand the effects of NPs in agricultural systems, this study investigates plant physiological and molecular responses upon exposure to AgNPs in comparison to silver nitrate (AgNO3). Tomato seedlings (Lycopersison esculentum) were exposed to 10, 20, or 30 mg/L silver (Ag), AgNO3, or AgNPs in hydroponic media for 7 days. A number of endpoints were measured, including plant growth, photosynthetic pigments, oxidative and antioxidant responses. The results showed 2-7 times lower growth rate in plants exposed to silver compared to the control. H2O2 and malondialdehyde as oxidative stress indicators were, respectively, 1.7 and 4 times higher in plants exposed to all forms of silver compared to the control. The antioxidative responses increased significantly in plants exposed to Ag and AgNPs compared to the control. However, plants exposed to AgNO3 showed up to 50% lower enzymatic antioxidant activity. At the molecular level, the expression of genes involved in defense responses, including ethylene-inducing xylanase (EIX), peroxidase 51 (POX), and phenylalanine ammonia lyase, were significantly upregulated upon exposure to silver. The molecular and physiological data showed exposure to all forms of silver resulted in oxidative stress and exposure to AgNPs induced antioxidative and defense responses. However, exposure to AgNO3 resulted in phytotoxicity and failure in antioxidative responses. It indicates the higher reactivity and phytotoxicity of the ionic form of silver compared to NPs. The findings of this study add important information to efforts in attempting to characterize the exposure and risk associated with the release of nanomaterials in the environment.

Antioxidant, physiological and biochemical responses of drought susceptible and drought tolerant mustard (Brassica juncea L) genotypes to rhizobacterial inoculation under water deficit stress.

Response of drought susceptible (DS) genotype Pusa Karishma LES-39 and drought tolerant (DT) mustard genotype NPJ-124, to rhizobacterial inoculation under water deficit stress, was compared in the present study to determine the influence of inoculants on biochemical and physiological attributes of these two different genotypes. Inoculation was observed to improve root and shoot dry weight in both the genotypes, although better results were observed in the DS genotype. There was variation in the response of the two genotypes to rhizobacterial inoculation, under water deficit stress. Significant improvement in most of the physiological and biochemical parameters including antioxidative enzyme activities of the DS genotype; with concomitant decrease in starch content, accumulation of H2O2 and lipid peroxidation upon inoculation of rhizobacteria was observed. In contrast, there was improvement in only few physiological and biochemical parameters in the DT genotype in response to inoculation with rhizobacteria. There was significant increase in catalase enzyme activity along with concomitant decrease in lipid peroxidation. Thus, drought susceptibility of the mustard genotypes, NPJ-124 and Pusa Karishma LES-39, determined their physiological, biochemical and antioxidative responses to rhizobacterial inoculation under water deficit stress. Expression of drought stress responsive genes belonging to ABA-dependent (RD20 and RD26) and ABA-independent (DREB2 and DREB1-2) pathways was studied in the DS genotype. Expression of DREB2 and DREB1-2 genes was considerably enhanced due to inoculation under water deficit stress; indicating that in Bacillus-mediated priming for drought stress tolerance, in this genotype, ABA-independent pathway probably played key role in enhancing tolerance to drought stress.

Tissue-Specific Antioxidative Responses and Cadmium Accumulation in Silurus meridionalis Under Chronic Waterborne Cadmium Exposure.

In this study, the oxidative damage, antioxidative responses and cadmium (Cd) accumulation in juvenile Silurus meridionalis were studied, after S. meridionalis were exposed to 0 (control), 62.5, 125, 250 and 500 µg Cd/L for 56 days. Cd accumulation, malondialdehyde, superoxide dismutase (SOD), catalase, glutathione (GSH) and total antioxidant capacity (T-AOC) were determined in gill, liver, kidney and intestine tissues. The results showed that the Cd accumulation in S. meridionalis was dose-dependent and tissue-specific, with the highest Cd content in the kidney, followed by the liver, gill, and intestine. Waterborne Cd stress in S. meridionalis was expressed as tissue-specific oxidative damage and antioxidant responses in gill, liver, kidney and intestine tissues. Waterborne Cd exposure induced the most significant oxidative damage in the gill, followed by the liver and kidney, while the intestine showed no sensitivity to waterborne Cd exposure. The antioxidants, such as SOD in the liver, kidney and intestine, as well as T-AOC and GSH in the gill, liver and kidney, were sensitive to waterborne Cd exposure.

The adaptability of a wetland plant species Myriophyllum aquaticum to different nitrogen forms and nitrogen removal efficiency in constructed wetlands.

Constructed wetlands (CWs) cultivated with Myriophyllum aquaticum showed great potential for total nitrogen (TN) removal from aquatic ecosystems in previous studies. To evaluate the growth characteristics, photosynthetic pigment content, and antioxidative responses of M. aquaticum, as well as its TN removal efficiency in CWs, M. aquaticum was treated with different levels of ammonium (NH4+) and nitrate (NO3-) for 28 days. The results indicated that M. aquaticum had strong nitrogen stress tolerance and was more likely to be suppressed by high levels of NH4+ than NO3-. High levels of NH4+ also led to inhibition of synthesis of photosynthetic pigments and increased peroxidase activity in plant leaves, which was not found in the NO3- treatments. High levels of both NH4+ and NO3- generated obvious oxidative stress through elevation of malondialdehyde content while decreasing superoxide dismutase activity in the early stage. A sustainable increase of TN removal efficiency in most of the CWs indicated that M. aquaticum was a candidate species for treating wastewater with high levels of nitrogen because of its higher tolerance for NH4+ and NO3- stress. However, the increase of TN removal efficiency was hindered in the late stage when treated with high levels of NH4+ of 26 and 36 mmol/L, indicating that its tolerance to NH4+ stress might have a threshold. The results of this study will enrich the studies on detoxification of high ammonium ion content in NH4+-tolerant submerged plants and supply valuable reference data for proper vegetation of M. aquaticum in CWs.

Changes in primary and secondary metabolites of Mentha aquatica L. exposed to different concentrations of manganese.

This experiment was conducted in order to determine the effects of different concentrations of manganese (Mn) on the levels and correlations of multiple primary and secondary metabolites in Mentha aquatica. With this aim, four levels of Mn concentrations were used as follows: basic Hoagland's solution (control), 40, 80, and 160 µM of Mn supplied as MnSO4.H2O. The results indicated that the biomass and the contents of photosynthetic pigments and soluble carbohydrates were higher in the plants that were treated with the moderate concentrations of Mn (40 and 80 µM) than the control and 160 µM-treated plants. On the other hand, the contents of flavonoids, anthocyanins, malonaldehyde (MDA), hydrogen peroxide (H2O2), and the activities of antioxidant enzymes (total superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX)) were progressively increased with the enhancement of Mn concentration in the nutrient solution. In addition, there were clear differences in the content and chemical composition of essential oils among the control and treatment groups. In this study, 1,8-cineole, menthofuran, and ß-caryophyllene were the most abundant constituents of essential oils in both the control and Mn-treated plants. The correlation analysis between pairs of the primary and secondary metabolites showed that there were positive and negative correlations among the variables when the Mn concentration was increased in the nutrient solution. These findings clearly display a positive effect of Mn up to 80 µM in the nutrient solution on the growth of M. aquatica.

Manganese modulates the physiological and biochemical responses of Mentha aquatica L. to ultraviolet radiation.

Ultraviolet (UV) radiation as an environmental factor alters the physiological and metabolic processes in plants. Manganese (Mn) is an essential element that is required for plant growth and development. This experiment was conducted in order to determine the effects of Mn supply and UV radiation on the physiological and metabolic responses in Mentha aquatica. With this aim, three levels of Mn and UV treatments were used as follows: basic Hoagland's nutrient solution without UV radiation (control), Mn supply (100µM), UV radiation (2h daily), and UV+100µM Mn. After three weeks of treatments, the root and shoot dry weights and the contents of photosynthetic pigments were decreased under UV radiation condition. However, the contents of flavonoids, soluble carbohydrate, anthocyanins, malonaldehyde (MDA), hydrogen peroxide (H2O2), and the activity of antioxidant enzymes (superoxide dismutase, catalase, and peroxidase) were increased. Interestingly, Mn at 100µM concentration decreased the harmful effects of UV radiation on M. aquatica. In addition, the clear differences were observed in the terpene constituents of M. aquatica after the Mn and UV treatments. In this study, 1, 8-cineole, menthofuran and ß-caryophyllene were the most abundant constituents of essential oils in both the control and treated plants. The correlation analysis between pairs of the primary and secondary metabolites showed that there were positive and negative correlations among the variables under the Mn supply and UV radiation conditions. These findings clearly display a positive effect of external Mn up to 100µM in the nutrient solution on the resistant of M. aquatica to UV radiation.

Copper toxicity and date palm (Phoenix dactylifera) seedling tolerance: Monitoring of related biomarkers.

Date palm (Phoenix dactylifera) seeds were exposed to different copper (Cu) solutions to examine plant stress responses. Low Cu concentrations (0.02 and 0.2 mM) caused an increase of seed germination, whereas higher Cu amounts (2 mM) significantly inhibited seed germination, delayed hypocotyl elongation, increased seedling mortality, and reduced the germination index by more than 90%. Metal-related toxicity symptoms appeared after 15 d of 2 mM of Cu exposure. Biochemical activities such as amylase activity and redox balance elements were examined to study the relationship between external Cu amount and internal plant response. The present study showed that amylolytic activity was dose- and time-dependent. Likewise, H2 O2 production increased after exposure to Cu, which was correlated with thiobarbituric acid reactive substance (TBARS) accumulation. Furthermore at low Cu concentrations, superoxide dismutase (SOD) and catalase (CAT) activities increased, suggesting that date palm seed stimulated its metal homeostasis networks. However, the highest cupric ion amounts increased cell oxidant accumulation and reduced enzyme production. Gene expression level measures of P. dactylifera phytochelatin synthase (Pdpcs) and P. dactylifera metallothionein (Pdmt) encoding genes have been carried out to investigate the implication of PdPCS and PdMT proteins in Cu homeostasis and/or its sequestration. Phoenix dactylifera metallothionein induction reached a peak after 30 d of exposure to 0.2 mM of Cu. However, it was down-regulated in plants exposed to higher Cu concentrations. In the same conditions, Pdpcs was overexpressed during 1 mo of exposure before it decreased thereafter. These observations provide a new insight into date palm cell response to Cu, a metal that can be toxic but that is also an essential element. Environ Toxicol Chem 2018;37:797-806. © 2017 SETAC.

Physiological, biochemical and molecular responses of Mentha aquatica L. to manganese.

Mentha aquatica is an aromatic herb which possesses valuable terpenoids constituents. Here, we intended to evaluate the effects of the different manganese (Mn) concentrations on the physiological, biochemical and molecular responses in M. aquatica. Basic Hoagland's solution (control), 40, 80, and 160 µM of Mn supplied as MnSO4·H2O were applied to the nutrient solution. The results indicated that the different concentrations of Mn differently affected the physiological, biochemical and molecular responses in M. aquatica. The growth parameters (biomass and photosynthetic pigments) and expression levels of ß-caryophyllene synthase (CPS), limonene synthase (Ls), geranyl diphosphate synthase (Gpps), and menthofuran synthase (Mfs) genes were increased at the moderate Mn concentrations (40 and 80 µM) and began to decrease at the higher levels. However, the contents of anthocyanins, flavonoids, malonaldehyde (MDA) and hydrogen peroxide (H2O2), Mn accumulation, activities of antioxidant enzymes, yield of essential oils and the expression levels of 1-Deoxy d-xylulose-5-phosphate synthase (Dxs) and isopentenyl diphosphate isomerase (Ippi) genes were gradually increased with increasing concentration of Mn in the nutrient solution. Also, the content and chemical composition of terpenoid constituents were altered in the Mn-treated plants. Here, we suggest that the application of external Mn in nutrient solution elevates the growth and expression levels of the genes that are involved in the terpenoid biosynthesis pathway in M. aquatica. Nevertheless, the extent and stability of these growth and gene expression elevation are varied among the different Mn treatments.

Interactive effects of cadmium and Microcystis aeruginosa (cyanobacterium) on the growth, antioxidative responses and accumulation of cadmium and microcystins in rice seedlings.

Cadmium pollution and harmful cyanobacterial blooms are two prominent environmental problems. The interactive effects of cadmium(II) and harmful cyanobacteria on rice seedlings remain unknown. In order to elucidate this issue, the interactive effects of cadmium(II) and Microcystis aeruginosa FACHB905 on the growth and antioxidant responses of rice seedling were investigated in this study, as well as the accumulation of cadmium(II) and microcystins. The results showed that the growth of rice seedlings was inhibited by cadmium(II) stress but promoted by inoculation of M. aeruginosa FACHB905. cadmium(II) stress induced oxidative damage on rice seedlings. Inoculation of M. aeruginosa FACHB905 alleviated the toxicity of cadmium(II) on rice seedlings. The accumulation of cadmium(II) in rice seedlings was decreased by M. aeruginosa FACHB905, but the translocation of cadmium(II) from root to shoot was increased by this cyanobacterium. The accumulation of microcystins in rice seedlings was decreased by cadmium(II). Results presented in this study indicated that cadmium(II) and M. aeruginosa had antagonistic toxicity on rice seedlings. The findings of this study throw new light on evaluation of ecological- and public health-risks for the co-contamination of cadmium(II) and harmful cyanobacteria.

Vegetable oils rich in alpha linolenic acid increment hepatic n-3 LCPUFA, modulating the fatty acid metabolism and antioxidant response in rats.

Alpha-linolenic acid (C18:3 n-3, ALA) is an essential fatty acid and the metabolic precursor of long-chain polyunsaturated fatty acids (LCPUFA) from the n-3 family with relevant physiological and metabolic roles: eicosapentaenoic acid (C20:5 n-3, EPA) and docosahexaenoic acid (C22:6 n-3, DHA). Western diet lacks of suitable intake of n-3 LCPUFA and there are recommendations to increase the dietary supply of such nutrients. Seed oils rich in ALA such as those from rosa mosqueta (Rosa rubiginosa), sacha inchi (Plukenetia volubis) and chia (Salvia hispanica) may constitute an alternative that merits research. This study evaluated hepatic and epididymal accretion and biosynthesis of n-3 LCPUFA, the activity and expression of Δ-5 and Δ-6 desaturase enzymes, the expression and DNA-binding activity of PPAR-α and SREBP-1c, oxidative stress parameters and the activity of antioxidative enzymes in rats fed sunflower oil (SFO, 1% ALA) as control group, canola oil (CO, 10% ALA), rosa mosqueta oil (RMO, 33% ALA), sacha inchi oil (SIO, 49% ALA) and chia oil (ChO, 64% ALA) as single lipid source. A larger supply of ALA increased the accretion of n-3 LCPUFA, the activity and expression of desaturases, the antioxidative status, the expression and DNA-binding of PPAR-α, the oxidation of fatty acids and the activity of antioxidant enzymes, whereas the expression and DNA-binding activity of SREBP-1c transcription factor and the biosynthetic activity of fatty acids declined. Results showed that oils rich in ALA such as SIO and ChO may trigger metabolic responses in rats such as those produced by n-3 PUFA.

Interaction between nanoparticles generated by zinc chloride treatment and oxidative responses in rat liver.

The aim of the present study was to investigate the interaction of zinc chloride (3 mg/kg, intraperitoneally [ip]) in rat liver in terms of the biosynthesis of nanoparticles. Zinc treatment increased zinc content in rat liver. Analysis of fluorescence revealed the presence of red fluorescence in the liver following zinc treatment. Interestingly, the co-exposure to zinc (3 mg/kg, ip) and selenium (0.20 mg/L, per os [by mouth]) led to a higher intensity of red fluorescence compared to zinc-treated rats. In addition, X-ray diffraction measurements carried out on liver fractions of zinc-treated rats point to the biosynthesis of zinc sulfide and/or selenide nanocomplexes at nearly 51.60 nm in size. Moreover, co-exposure led to nanocomplexes of about 72.60 nm in size. The interaction of zinc with other mineral elements (S, Se) generates several nanocomplexes, such as ZnS and/or ZnSe. The nanocomplex ZnX could interact directly with enzyme activity or indirectly by the disruption of mineral elements' bioavailability in cells. Subacute zinc or selenium treatment decreased malondialdehyde levels, indicating a drop in lipid peroxidation. In addition, antioxidant enzyme assays showed that treatment with zinc or co-treatment with zinc and selenium increased the activities of glutathione peroxidase, catalase, and superoxide dismutase. Consequently, zinc complexation with sulfur and/or selenium at nanoscale level could enhance antioxidative responses, which is correlated to the ratio of number of ZnX nanoparticles (X=sulfur or X=selenium) to malondialdehyde level in rat liver.