A study of lipid- and water-soluble arsenic species in liver of Northeast Arctic cod (Gadus morhua) containing high levels of total arsenic

In the present study liver samples (n = 26) of Northeast Arctic cod (Gadus morhua), ranging in total arsenic concentrations from 2.1 to 240 mg/kg liver wet weight (ww), were analysed for their content of total arsenic and arsenic species in the lipid-soluble and water-soluble fractions. The arsenic concentrations in the lipid fractions ranged from 1.8 to 16.4 mg As/kg oil of liver, and a linear correlation (r² = 0.80, p < 0.001) was observed between the total arsenic concentrations in liver and the total arsenic concentrations in the respective lipid fractions of the same livers. The relative proportion of arsenolipids was considerably lower in liver samples with high total arsenic levels (33–240 mg/kg ww), which contained from 3 to 7% of the total arsenic in the lipid-soluble fraction. In contrast liver samples with low arsenic concentrations (2.1–33 mg/kg ww) contained up to 50% of the total arsenic as lipid-soluble species. Arsenic speciation analysis of the lipid-soluble fractions of the livers, using reversed-phase high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC–ICP-MS), revealed the presence of several arsenolipids. Three major arsenic-containing hydrocarbons (C₁₇H₃₉AsO, C₁₉H₄₁AsO and C₂₃H₃₇AsO) and five arsenic-containing fatty acids (C₁₇H₃₅AsO₃, C₁₉H₃₉AO₃, C₁₉H₃₇AsO₃, C₂₃H₃₇AsO₃ and C₂₄H₃₇AsO₃) were identified using HPLC coupled to quadrupole time-of-flight mass spectrometry (qTOF-MS). Arsenobetaine was the major arsenic species in the water-soluble fraction of the livers, while dimethylarsinate, arsenocholine and inorganic arsenic were minor constituents. Inorganic arsenic accounted for less than 0.1% of the total arsenic in the liver samples.     

Anti adipogenic activity of Aegle marmelos Correa

In continuation of evaluating the anti-obesity effect of Aegle marmelos, we have screened the n-hexane, dichloro methane (DCM), ethyl acetate (EtOAc) and methanol (MeOH) extracts of the leaves at the concentration of 25, 50, 75 and 100 μg/ml for adipogenesis inhibition in the adipocytes. Nile red staining with the help of fluorometry was used as indicator of the antiobesity activity. The most active DCM extract showed the 33.98 ± 3.55% lipid content at 100 μg/ml and was selected for the further isolation. 14 compounds were isolated from DCM extract of A. marmelos leaves. The compounds were screened for the adipogenesis inhibition at 50 and 100 μM concentrations. Out of the 14 compounds, halfordinol, ethyl ether aegeline and esculetin were showing 10.04 ± 0.52, 16.29 ± 0.85 and 25.09 ± 1.31% lipid content respectively at 100 μM. We hereby report the adipogenesis inhibition by A. marmelos as one of the pathway for its antiobesity effect.     

Bioguided fractionation and isolation of natural inhibitors of advanced glycation end-products (AGEs) from Calophyllum flavoramulum

Advanced glycation end-products (AGEs) are associated with many pathogenic disorders such as Alzheimer’s disease, pathogenesis of diabetes, atherosclerosis or endothelial dysfunction leading to cardiovascular events. Clusiaceae and Calophyllaceae families are rich in compounds like polyphenols which are able to inhibit their formation and are therefore of great interest. Calophyllum flavoramulum Hend. & Wyatt-Sm., a native Malaysian plant, was selected after an anti-AGEs screening conducted on DCM and MeOH extracts from plants belonging to these aforementioned families. In a first study, bioguided fractionation of the MeOH leaf extract of C. flavoramulum afforded amentoflavone, 3-methoxy-2-hydroxyxanthone, 3,4-dihydroxy-tetrahydrofuran-3-carboxylic acid, quercitrin, 3,4-dihydroxybenzoic acid, canophyllol and apetalactone. Amentoflavone and 3-methoxy-2-hydroxyxanthone were found to be very potent (IC₅₀ = 0.05 and 0.06 mM respectively), while anti-AGEs activities of quercitrin and 3,4-dihydroxybenzoic acid appeared as moderately strong (IC₅₀ = 0.5 mM). In a second study, a systematic phytochemical study of the cyclohexane, DCM and EtOAc extracts obtained from the same plant was conducted to isolate the following products: flavoramulone, 6-deoxyjacareubin, rheediachromenoxanthone, 2,3-dihydroamentoflavone and benzoic acid. 3,4-Dihydroxy-tetrahydrofuran-3-carboxylic acid and flavoramulone were isolated for the first time and their structures were identified by means of IR, MS and NMR spectrometries.     

Comparison between hepatic and renal effects in rats treated with arsenic and/or antioxidants during gestation and lactation

The aim of this study was to determine whether biochemical changes occurred in the liver and kidney of arsenic (As) exposed pups during gestation and lactation, and investigate the potential beneficial role of antioxidants against arsenic exposure damage. Pregnant wistar rats received the following treatments as drinking water: (1) distilled water; (2) arsenic (50 mg/L); (3) antioxidants: zinc (20 mg/L) + vitamin C (2 g/L) + vitamin E (500 mg/L); (4) arsenic (50 mg/L) + antioxidants. As- intoxicated pups showed significant decreases in liver cholesterol and triglyceride concentration, whereas Aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were increased. Treatment with antioxidants returns these values to control ones. TBARS production in both organs and liver glutathione peroxidase (GPx) activity also increased whereas catalase (CAT) activity in both organs decreased in arsenic-exposed pups; the antioxidant administration only recover TBARS concentration to control values. Our findings suggest that administration of antioxidants during gestation and lactation could prevent some of the negative effects of arsenic.     

Optimization of a rapid microwave-assisted extraction method for the simultaneous determination of opiates,cocaine and their metabolites in human hair

A rapid and cleanup-free microwave-assisted extraction (MAE) method is proposed for the simultaneous extraction of six illegal drugs of abuse – cocaine, benzoylecgonine (BZE), cocaethylene (CCE), morphine, 6-monoacethylmorphine (6AM) and codeine – from human hair samples. The analytes were determined using high performance liquid chromatography (HPLC) with photodiode array UV detection. The influence of several variables on the efficiency of the MAE procedure was investigated in detail by a multi-objective optimization approach based on a hybrid experimental design (17 experiments) and desirability functions. Six drugs were successfully extracted from human hair with recoveries close to 100% and good reproducibility (<3.6% RSD) under the optimal MAE conditions: 11 mL dichloromethane (DCM) extraction solvent, 60 °C extraction temperature, 9 min extraction time and 0.5 mL of methanol (MeOH) added to 50 mg of the hair sample in the extraction vessels. Limits of quantification of 0.2 ng mg^?1 were found for the studied compounds. A comparison of sample preparation procedures, including MAE, enzymatic digestion and digestion by aqueous acids, was also conducted. The results indicated that the global behaviour of sample procedures provided similar satisfactory recoveries ranging from 86 to 100%. Indeed, the MAE procedure resulted in a reduction of extraction time by 100-fold and the elimination of cleanup steps. Slightly higher recoveries of morphine, 6AM, BZE and CCE, at 1 ng mg^?1 concentration level and cocaine at 40 ng mg^?1 concentration level, were achieved using MAE. Lastly, the proposed MAE method was applied to several human hair samples from multidrug abusers.     

Use of the size fractionation of the macrobenthic biomass for the rapid assessment of benthic organic enrichment

A new biomass index for monitoring the impact of marine fish cage farming on the benthic environment was evaluated at seven commercial fish farms in the eastern Mediterranean. At each farm, stations near and further away from the cages were sampled for macrofauna and geochemical variables during July 2001, and March and October 2002. Benthic samples were sequentially sieved through 1.0 and 0.5 mm mesh screens and a biomass fractionation index (BFI) was estimated as follows: biomass having passed through 1.0 mm and retained on 0.5 mm sieve only/total biomass (biomass retained on 1.0 mm + 0.5 mm sieve). BFI was quantitatively assessed and compared with the geochemical faunistic and management practice data. BFI was found to decrease consistently with distance from fish cages and particularly after 10 m from the edge of the cages. At all farms, BFI was found to be significantly correlated with distance, redox potential and organic carbon. Multiple regression analysis showed that BFI incorporates various components of sediment geochemistry (sediment grain size and total organic carbon) as well as distance and feeding rates. Although BFI needs to be further tested in different geographic locations and under different management practices, the results seem to be promising for long-term monitoring programmes since it provides a simple and inexpensive solution for assessing the effects of benthic organic enrichment due to fish farm activities.     

Effects of nutrients on arsenic accumulation by arsenic hyperaccumulator Pteris vittata L.

This research investigated the effects of various nutrients on arsenic (As) removal by arsenic hyperaccumulator Pteris vittata L. in a Hoagland nutrient solution (HNS). The treatments included different concentrations of Ca and K in 20% strength of HNS, different strengths of HNS (10, 20 and 30%), different strengths of HNS (10 and 20%) with and without CaCO₃, and different concentrations of Ca, K, NO₃, NH₄, and P in 20% strength of HNS. The plants were grown in nutrient solution containing 1 mg As L^?1 for 4 weeks except the Ca/K experiment where the plants were grown in nutrient solution containing 10 or 50 mg As L^?1 for 1 week. Adding up to 4 mM Ca or 3 mM K to 20% strength HNS significantly (P < 0.05) increased plant arsenic accumulation when the solution contained 10 mg As L^?1. Plant arsenic removal was reduced with increasing Ca and K concentrations at 50 mg As L^?1. Lower strength of HNS (10%) resulted in the greatest plant arsenic removal (79%) due to lower competition of P with As for plant uptake. Addition of CaCO₃ to 20% strength of HNS significantly increased arsenic removal by P. vittata. Among the nutrients tested, NO₃ and CaCO₃ were beneficial to plant arsenic removal while NH₄, P and Cl had adverse effects. This experiment demonstrated that it is possible to optimize plant arsenic removal by adjusting nutrients in the growth medium.     

Quercetin in vesicular delivery systems: Evaluation in combating arsenic-induced acute liver toxicity associated gene expression in rat model

Arsenic, the environmental toxicant causes oxidative damage to liver and produces hepatic fibrosis. The theme of our study was to evaluate the therapeutic efficacy of liposomal and nanocapsulated herbal polyphenolic antioxidant Quercetin (QC) in combating arsenic induced hepatic oxidative stress, fibrosis associated upregulation of its gene expression and plasma TGF ß (transforming growth factor ß) in rat model.A single dose of Arsenic (sodium arsenite-NaAsO₂, 13 mg/kg b.wt) in oral route causes the generation of reactive oxygen species (ROS), arsenic accumulation in liver, hepatotoxicity and decrease in hepatic plasma membrane microviscosity and antioxidant enzyme levels in liver. Arsenic causes fibrosis associated elevation of its gene expression in liver, plasma TGF ß (from normal value 75.2 ± 8.67 ng/ml to 196.2 ± 12.07 ng/ml) and release of cytochrome c in cytoplasm. Among the two vesicular delivery systems formulated with QC, polylactide nanocapsules showed a promising result compared to liposomal delivery system in controlling arsenic induced alteration of those parameters. A single dose of 0.5 ml of nanocapsulated QC suspension (QC 2.71 mg/kg b.wt) when injected to rats 1 h after arsenic administration orally protects liver from arsenic induced deterioration of antioxidant levels as well as oxidative stress associated gene expression of liver. Histopathological examination also confirmed the pathological improvement in liver. Nanocapsulated plant origin flavonoidal compound may be a potent formulation in combating arsenic induced upregulation of gene expression of liver fibrosis through a complete protection against oxidative attack in hepatic cells of rat liver.     

Texture analysis in liver of common carp (Cyprinus carpio) sub-chronically exposed to perfluorooctanoic acid

An operator-neutral, objective method was implemented to comparatively assess liver pathology in 30 specimens of common carp (Cyprinus carpio): 20 after experimental flow-through exposure to two perfluorooctanoic acid (PFOA) dosages (10 fish exposed to 200 ng l⁻¹ and 10 fish exposed to 2 mg l⁻¹) for 56 days and 10 unexposed (negative control). The method relies on texture analysis as a complementary approach to traditional histopathology and chemical dosage analysis performed previously on the same experimental material. Texture features data were analyzed by means of Redundancy Analysis (RDA), Linear Discriminant Analysis (LDA) and Canonical Variates Analysis (CVA). LDA resulted in the correct classification of 80% of cases (24 out of 30 cases) with a sensitivity of 83.3% and a specificity of 83.3. In particular, four male samples from the low dosage group (200 ng l⁻¹) were misclassified as unexposed fish and two female samples from the unexposed group were misclassified as low dosage exposed. Nevertheless, PFOA liver chemical dosage analysis results were the same both in unexposed and in low dosage group fish, all below the limit of detection. No sample from the high dosage group (2 mg l⁻¹) has ever been misclassified. Interestingly, texture features correlated with the PFOA concentrations detected in the liver of each sampled fish. In the present study the technique of texture analysis was combined with techniques of multivariate exploratory data analysis (RDA, LDA/CVA). This approach resulted in a robust, sufficiently sensitive and specific means to study PFOA-induced liver pathology. The new method can discriminate between unexposed and two PFOA exposed groups with better confidence and in a more affordable way, compared to chemical quantification of liver PFOA. The texture features correlated well with liver PFOA concentrations and objectively quantified degenerative liver morphology. In conclusion the overall approach may be a suitable candidate as a reliable and broad-ranging method for biomarker analysis of exposure and effect.     

Arsenic reduced scale-insect infestation on arsenic hyperaccumulator Pteris vittata L.

Arsenic hyperaccumulation by Pteris vittata L. (Chinese brake fern) may serve as a defense mechanism against herbivore attack. This study examined the effects of arsenic exposure (0, 5, 15 and 30 mg kg^?1) on scale insect (Saissetia neglecta) infestation of P. vittata. Scale insects were counted as a percentage fallen from the plant to the total number of insects after 1 week of As-treatment. The arsenic concentrations in the fronds ranged from 5.40 to 812 mg kg^?1. Greater arsenic concentrations resulted in higher percentage of fallen-scale insects (17.2–55.0%). Lower arsenic concentrations (≤5 mg kg^?1) showed significantly lower effect on the population compared to 15–30 mg kg^?1 (p < 0.05). Arsenic content in the fallen-scale insects was as high as 194 mg kg^?1, which indicated that arsenic has been ingested by the scale insects via plant sap. This study is consistent with the hypothesis that arsenic may help P. vittata defend against herbivore's attack.     

Determination of selenium and its compounds in marine organisms

In this study, we investigate the type and quantity of selenium compounds in fish and marine organisms, using ion-pair reversed phase LC–ICP-MS, developed and applied for the analysis of Atlantic cod, Atlantic salmon, Greenland halibut, Atlantic herring, blue mussel, common crab, scallop, calanus, and Euphasia super. Of the samples examined, the lowest level of selenium was found in farmed Atlantic salmon (0.17 mg Se kg⁻¹ dm). The total selenium extraction efficiency by phosphate buffer was 2.5 times higher in sea plankton and shellfish samples than in fish samples. Analysis of Se species in each hydrolysate obtained by proteolysis showed the presence of selenomethionine, which constituted 41.5% of the selenium compounds detected in hydrolysates of Atlantic herring and 98.4% of those in extracts of Atlantic salmon. Inorganic compounds, such as selenates and selenites, were detected mainly in sea plankton and shellfish samples (<0.13 mg Se kg⁻¹ wm), although no correlation was found between the presence of inorganic compounds and total selenium concentration. The accuracy of the total selenium determination was validated using a certified reference material (oyster tissue (NIST 1566b)). A lyophilised powder of cod (Gadus morhua) was used to validate speciation analysis, enzymatic hydrolysis of lyophilised powder of cod recovered 54 ± 6% of total selenium, and SeMet constituted 83.5 ± 5.28% of selenium detected in hydrolysates. The chromatographic detection limits were, respectively, 0.30 ng mL⁻¹, 0.43 ng mL⁻¹, 0.54 ng mL⁻¹, 0.55 ng mL⁻¹, 0.57 ng mL⁻¹ and 0.72 ng mL⁻¹ for selenate, selenomethionine, selenite, Se-methyl-selenocysteine, selenocystine and selenomethionine selenoxide.The data on selenium concentrations and speciation presented here could be useful in estimating levels of selenium intake by seafood consumption.     

Determination of p-phenylenediamine and its metabolites MAPPD and DAPPD in biological samples using HPLC-DAD and amperometric detection

A sensitive and selective HPLC method using a diode array detector (DAD) and an electrochemical detector (ECD) in series has been developed and validated for the quantitative measurement of p-phenylenediamine and its acetylated metabolites N-acetyl-p-phenylenediamine (MAPPD) and N,N′-diacetyl-p-phenylenediamine (DAPPD) in biological samples. The separation was carried out on a hydrophilic modified AQUA C₁₈ column and the mobile phase was composed of acetonitrile: ammonium acetate solution (5:95, 25 mM, v/v). Spectrophotometric detection was performed at 240 or 255 nm and amperometric detection was carried out using a positive oxidation potential of 400 mV. The quantification of the three analytes was validated in the range of 0.05–50 μM and the established limits of determination were 0.5 μM for PPD and MAPPD and 1 μM for DAPPD. The standard deviations (N = 9) were lower than 7.5% at a concentration of 1 μM. The samples were stabilised with ascorbic acid to prevent PPD from oxidizing. Pretreatment of samples or analyte enrichment before sample injection is not required. The method proved to be accurate, sensitive and sufficiently specific. It was applied to the ecotoxicological study of the kinetics of the PPD N-acetylation in cell lysates in two different media.     

Dietary alpha-linolenic acid does not enhance accumulation of omega-3 long-chain polyunsaturated fatty acids in barramundi (Lates calcarifer)

This study examined the effects of substituting fish oil and fish meal with a blend of alpha-linolenic acid (ALA, 18:3 n ? 3) rich vegetable oils (14%, w/w) and defatted poultry meal (34%, w/w) in a formulated diet, on growth and tissue fatty acid profiles in barramundi fingerlings. Results indicated that on average, while the ALA levels of the barramundi liver and fillet increased with increasing dietary ALA, there was no corresponding increase in the levels of the omega-3 (n ? 3) long chain polyunsaturated fatty acid (LCPUFA). Compared to fish consuming a commercial feed, which contained fish meal and fish oil, fish on the ALA diets grew slower, had a lower feed intake and lower n ? 3 LCPUFA levels in the tissues. Hepatic mRNA expression of Δ6 desaturase (FADS2) and elongase (ELOVL5/2) was ~ 10 fold and ~ 3 fold higher, respectively, in all the ALA dietary groups, relative to those fed the commercial feed. However, the level of expression of the two genes was not different between fish fed differing ALA levels. These data demonstrate that increasing the ALA level of the diet is not an appropriate strategy for replacing marine sources of n ? 3 LCPUFA in barramundi. It was also noted, however, that within the different ALA dietary groups there was a large amount of variation between individual fish in their tissue DHA levels, suggesting a significant heterogeneity in their capacity for conversion of ALA and/or retention of n ? 3 LCPUFA. When dietary ALA intakes were greater than 0.8% en, tissue DHA levels were inversely related to ALA intake, suggesting that high intake of dietary ALA may inhibit DHA synthesis.     

Occurrence of toxic Prymnesium parvum blooms with high protease activity is related to fish mortality in Hungarian ponds

The unicellular alga Prymnesium parvum has been responsible for toxic incidents with severe ecological impacts in many parts of the world, and causes massive fish kills worldwide. Recently the haptophyte microalgae have caused water-bloom (4.3 × 10⁴ cells ml⁻¹) in 6 fish ponds with high conductivity in Hungary, and caused fish mortality with typical symptoms. Toxicity of P. parvum from water samples was quantified by the assay of the influence of its cell-free filtrates on haemolysis (346 ± 42.2) and in fish and daphnia toxicity tests. High amount of proteases in P. parvum containing waterbloom samples were detected with the help of activity gel electrophoresis. The proteases of investigated P. parvum samples (125–18 kDa) showed high gelatinolytic activity and some of them showed sensitivity to EDTA (inhibitors of metalloproteases) and to PMSF (inhibitors of serine proteases).     

Mercury levels assessment in hair of riverside inhabitants of the Tapajós River,Pará State,Amazon, Brazil: Fish consumption as a possible route of exposure

The study present evaluated the levels of mercury (Hg) and methylmercury (MeHg) in hair samples of people from Barreiras community, riverside inhabitants of the Tapajós River (Pará, Brazil), an area impacted by clandestine gold mining, as well as we analyzed the levels of Hg and Se (selenium) in nine fish species (carnivores and non-carnivorous) from the Tapajós River, which stand out as the main species consumed by riverside inhabitants, to evaluate a relationship between frequency of fish consumption and Hg concentration, and also to evaluate possible mechanisms of fish protection (or non-protection) to Hg exposure by Se. Furthermore we analyze the water quality to evaluate the environmental trophic state, fact responsible by creating conditions that can potentiate the effects of toxic mercury. Concentrations of Hg and MeHg were analyzed in hair samples of 141 volunteers in different age band. Of those, 84.40% of samples present values above the threshold for biological tolerance, which is 6.00 μg g⁻¹ of total Hg in hair. Total Hg, in men there was a variation of 2.07–24.93 μg g⁻¹, while for women the variation was 4.84–27.02 μg g⁻¹. Consequently, the level of MeHg in men presented a variation of 1.49–19.57 μg g⁻¹, with an average of 11.68 μg g⁻¹, while with women the variation was from 3.73 to 22.35 μg g⁻¹, with an average of 10.38 μg g⁻¹. In fish species, Hg concentrations in carnivorous species had an average of 0.66 μg g⁻¹, higher than that permitted by current legislation, ranging from 0.30 to 0.98 μg g⁻¹, while the non-carnivorous species have values below the recommended by the legislation averaging 0.09 μg g⁻¹, ranging between 0.02 and 0.44 μg g⁻¹. For Se in fish, show that among carnivores, the contents of Se ranged between 0.18 and 0.54 μg g⁻¹ with a mean of 0.34 μg g⁻¹, while for non-carnivores these values were of the order of 0.16–0.56 μg g⁻¹, with an average of 0.32 μg g⁻¹. In surface water quality variables at the sampling points all showed values in accordance with the range established by current legislation. In this regard, the results provided by this study, while not conclusive, are strong indicators that despite not having been shown the relationship between the concentration of mercury in hair and feeding habits along the Tapajós River basin communities showed that a plausible correlation exists between levels of mercury and selenium in fish. This fact may serve as a subsidy to research human health, because in the Amazon, there is still a lot to examine with regards to the full understanding of the Se cycle.     

Seasonal variations in the body composition and bioaccumulation of heavy metals in Nile tilapia collected from drainage canals in Al-Ahsa,Saudi Arabia

The body composition of Nile tilapia (Oreochromis niloticus) collected from drainage canals in Al-Ahsa, Saudi Arabia and the concentration of four heavy metals; zinc (Zn), cadmium (Cd), cobalt (Co) and lead (Pb) in both fish muscles and the water collected from this environment were assessed across the four seasons. The body composition was found to change with the seasons, with the best body composition being recorded in autumn and winter, where higher levels of protein (17.24, 17.65%), and fat (0.58, 0.71%) and lower water content (80.15, 79.86%) respectively were noted. The concentration of heavy metals in both fish muscles and the water body also varied significantly with the seasons. In the fish muscles, the highest content of Zn (0.409 mg/kg dry weight) and Cd (4.140 mg/kg dry weight) was recorded in winter, however, the highest concentration of Co (0.318 mg/kg dry weight) and Pb (1.96 mg/kg dry weight) was observed in spring and summer respectively. On the other hand, the water samples collected in autumn showed the maximum concentration of Cd (1.385 mg/L), Co (0.762 mg/L) and Pb (0.18 mg/L) however, the maximum concentration of Zn (0.0041 mg/L) was recorded in winter. With the exception of Cd, the accumulation of the studied heavy metals in fish muscles was within the safe limits for seafood recommended by various organizations.     

Removal of iron,arsenic and coliform bacteria from water by novel constructed soil filter system

The present paper presents results of the study in removal of iron, arsenic and total coliform from drinking water using single-pass constructed soil filter (CSF). Results indicated that arsenic levels ranged from 0.5 to less than 10 μg l^?1 levels; iron from 5 to less than 0.3 mg l^?1 and coliform from 10^?5 to less than 5 CFU/100 ml. The results revealed very high removal efficiency, i.e., over 99% and water quality as per WHO standard.     

Effect of vitamin E supplementation on arsenic induced alteration in blood biochemical profile,oxidant/antioxidant status,serum cortisol level and retention of arsenic and selenium in goats

Arsenic (As) exerts oxidative stress with depletion of body selenium in monogastric animals. But in ruminants this fact is not yet verified. Vitamin E is an effective dietary antioxidant. Thus, in this experiment, the protective effect of vitamin E against arsenic toxicity induced by sodium arsenite (60 mg As/kg diet) was investigated in goat kids. For this, 21 male kids were divided into three equal groups and fed either basal diet as such (control), or supplemented with 60 mg As/kg diet and 60 mg As/kg diet + 250 IU vitamin E/kg diet for 180 days. Vitamin E supplementation alleviated the toxic effects caused by arsenic on serum alanine aminotransferase and aspartate aminotransferase and lipid peroxidation. It also prevented the depletion of reduced glutathione content and reduction in activity of catalase, superoxide dismutase and glutathione-s-transferase in erythrocytes resulted from arsenic intoxication. The elevated levels of arsenic and reduced levels of selenium in the serum and tissues in arsenic treated animals were attenuated by vitamin E supplementation, though not completely. However, serum cortisol level was not affected by arsenic. It was concluded that arsenic exerts cortisol independent stressor mechanism and supplementation of vitamin E at a level of 250 IU/kg diet was partially effective in reducing tissue accumulation of arsenic in the body and protect the kids from oxidative stress induced by arsenic.     

Monitoring of trace metals in tissues of Wallago attu (lanchi) from the Indus River as an indicator of environmental pollution

We aimed to assess the bioaccumulation of selected four trace metals (Cd, Ni, Zn and Co) in four tissues (muscles, skin, gills and liver) of a freshwater fish Wallago attu (lanchi) from three different sites (upstream, middle stream and downstream) of the Indus River in Mianwali district of Pakistan. Heavy metal contents in water samples and from different selected tissues of fish were examined by using flame atomic absorption spectrometry. The data were statistically compared to study the effects of the site and fish organs and their interaction on the bioaccumulation pattern of these metals at P < 0.05. In W. attu the level of cadmium ranged from 0.004 to 0.24; nickel 0.003–0.708; cobalt 0.002–0.768 and zinc 47.4–1147.5 μg/g wet weight. The magnitude of metal bioaccumulation in different organs of fish species had the following order gills > liver > skin > muscle. The order of bioaccumulation of these metals was Ni < Zn < Co < Cd. Heavy metal concentrations were increased during the dry season as compared to the wet season. The results of this study indicate that freshwater fish produced and marketed in Mianwali have concentrations below the standards of FEPA/WHO for these toxic metals.     

Production of hemicellulosic sugars and glucose from residual corrugated cardboard

Corrugated cardboard samples were subjected to two-step saccharification. A first prehydrolysis stage was carried out to solubilise the hemicellulosic fraction as hemicellulosic sugars, and the solid phase from prehydrolysis was used as a substrate for the enzymic hydrolysis of cellulose. The prehydrolysis step was carried out for 0–180 min in media containing 1–3 wt.% of H₂SO₄ and the fraction of solid recovered after treatments and the compositions of solid and liquid phases from treatments were measured. The susceptibility of prehydrolysed solids towards the enzymic hydrolysis was assessed in further experiments. Under selected prehydrolysis conditions (3% H₂SO₄, 180 min), 78.2% of initial hemicelluloses was saccharified, leading to liquors containing up to 10 g hemicellulosic sugars/l and 9.2 g glucose/l. The corresponding solid phase, enriched in cellulose, showed good susceptibility towards enzymatic hydrolysis, leading to solutions containing up to 17.9 g glucose/l (conversion yield=63.6%) and a glucose/total sugar ratio of 0.93 g/g. Mathematical models assessing the effects of the operational conditions on both the prehydrolysis stage and the susceptibility of substrates towards enzymic hydrolysis have been developed.