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Background: Indian meal moth (Plodia interpunctella) is a significant pest infesting stored grains, particularly maize. Over time, synthetic insecticides have been employed to control insect. The residual effects posed on non-target organisms have called for replacement of synthetic insecticides with botanicals. This study therefore aimed at comparing the insecticidal consistency and oxidative stress invoked by dichlorvos (DDVP) and the oil extract of ginger (Zingiber officinale) on Indian meal moth infesting maize. Disinfested maize grains were treated with DDVP and ginger oil extract separately. Adults P. interpunctella were introduced to the treated grains daily using complete replacement method. The percentage mortality was calculated daily for 10 d. Furthermore, the oxidative stress caused by DDVP and ginger oil extract on the moth was evaluated by measuring the level of some oxidative stress biomarkers such as glutathione S-transferase, superoxide dismutase, glutathione peroxidase (GPx), and catalase (CAT) activity in the exposed insects. Results: Preliminary results indicated that both DDVP and ginger oil extract exhibited insecticidal properties against Indian meal moth infesting maize. However, the insecticidal (active) period of ginger oil extract was found to be longer than that of DDVP. Nevertheless, DDVP provoked greater oxidative stress in the exposed moth. Conclusions: Ginger oil extract and DDVP show potential for controlling Indian meal moth infestations in stored maize. Yet, ginger oil offers a longer-lasting effect on pest suppression and control. Consequently, it could be a replacement or synergistic insecticide with DDVP to provide ecofriendly insecticide application. [ABSTRACT FROM AUTHOR]

Hexavalent chromium (Cr6+) is one of the stable oxidation states of chromium that has been reported to elicit various toxic effects in aquatic organisms. However, the mechanisms of Cr6+ toxicity are still poorly understood. Thus, the present study investigated the tissue accumulation, cytotoxic, oxidative stress, and immunotoxic effects of Cr6+ in juvenile Clarias gariepinus. The fish were exposed to waterborne Cr6+ concentrations (0, 0.42, 0.84, and 1.68 mg/L) for 28 days, after which they were sacrificed and various organs were harvested for the determination of Cr6+ levels. Other parameters that were indicators of oxidative stress, cytotoxicity, and immunotoxicity were measured. Cr6+ accumulated more in the kidney and liver of the exposed fish, especially at the highest concentration. The levels of lipid peroxidation and DNA fragmentation increased significantly in the exposed fish. The activities of superoxide dismutase and lactate dehydrogenase increased significantly in exposed fish compared to the control. The total white blood cells, lymphocytes, and neutrophils counts were significantly higher in the exposed fish compared to the control fish. The respiratory burst activity decreased significantly in the exposed fish while the myeloperoxidase content did not differ significantly. There were upregulations of TNF-α and HSP 70 while CYP II and MHC 2 were downregulated in the exposed fish. Also, exposure to Cr6+ resulted in various histopathological alterations in the architecture of the head kidney. The results indicate concentration-dependent toxic effects of Cr6+ in C. gariepinus. The study reveals the potentials of Cr6+ to accumulate in the different tissues of fish and caused cytotoxic, oxidative stress, and immunotoxic effects in the exposed fish. [ABSTRACT FROM AUTHOR]

Maize is a staple grain cereal that is consumed worldwide for the supply of daily energy requirements. However, its infestation by the weevil, Sitophilus zeamais often results in both qualitative and quantitative losses, which must be managed effectively. The health hazards that are associated with the application of synthetic insecticides for the management of pest infestations of stored products have necessitated the continual sourcing of safer and affordable alternatives. Hence, a laboratory experiment was conducted to assess the effects of morphological, biophysical and some intrinsic factors in fifteen improved maize varieties on their susceptibility or otherwise resistance to infestation by the maize weevil, S. zeamais. Firstly, the morphological and biophysical characteristics of the maize varieties were determined. Copulating pairs of adult S. zeamais were placed in containers that contained undamaged maize grains for seven days to allow for oviposition, after which the adults were removed. Thereafter, the number of eggs laid and adults that emerged were counted. The susceptibility index of each maize variety was calculated from the data obtained from oviposition and adult emergence. Also, the proximate, elemental, and antinutrient compositions of the maize varieties were determined. There was no significant difference (p > 0.05) in the size and hardness of seeds among the varieties with the size range of 0.78–0.95 cm3 while the hardness ranged from 17.43 N in SAMMAZ-15 F to 19.08 N in SAMMAZ-35. The maize varieties differed significantly with respect to proximate, elemental, and antinutrient compositions. The susceptibility of the seeds to infestations by S. zeamais differed significantly among the varieties and across the generations, with the potential for loss of resistant property during later generations. The data from the susceptibility index revealed that TZL COMP4, TZEE W POP and SAMMAZ-29 were the most resistant to infestations by S. zeamais. Although, several factors could have been responsible for the susceptibility or resistance of maize seed varieties to infestations by S. zeamais, however oviposition hardness and moisture were the most important factors in the present study. [ABSTRACT FROM AUTHOR]

The objective of the study was to determine the comparative toxicities and immune dysfunction in the African catfish, Clarias gariepinus, exposed to bisphenol A (BPA) and its two analogues: bisphenol AP (BPAP) and bisphenol P (BPP). Juveniles of C. gariepinus were exposed to sublethal concentrations (70 and 140 μg/L) of BPA, BPAP and BPP for 7, 14 or 21 days after which various endpoints which are indicative of cytotoxicity, oxidative stress and haematological and innate immune parameters were determined in the liver homogenates or blood plasma. The exposure of C. gariepinus to BPA and its analogues caused significant increased activities of lactate dehydrogenase, catalase and superoxide dismutase. The exposed fish had increased levels of DNA fragmentation, lipid peroxidation, white blood cells, nitric oxide and respiratory burst, while the red blood cell counts and the percentage packed cell volume decreased significantly in the exposed fish compared to control. The toxic effects elicited by the bisphenols were both concentration- and duration-dependent. Generally, BPA exerted the most toxic effects on the fish, followed by BPAP, while BPP exerted the least toxic effects to C. gariepinus. Summarily, the findings indicated that BPA and its two analogues studied in the research are capable of causing cytotoxicity, oxidative stress and immune dysfunction in C. gariepinus. [ABSTRACT FROM AUTHOR]

The pathogenic enterobacterium, Serratia marcescens, is a potential fish pathogen having been isolated in fish culturing environments. However, information on its effects on the physiology of cultured fish species is scarce. This study therefore aimed at ascertaining the physiological status of African catfish (Clarias gariepinus) that has been experimentally challenged with S. marcescens. Healthy juvenile C. gariepinus were experimentally challenged with either 1 × 104 CFU/ml or 5 × 104 CFU/ml inoculums of S. marcescens via oral gavage and the hematological (percentage packed cell volume (PCV), red blood cells (RBC) counts, white blood cells (WBC), counts and differential leucocytes counts) and innate humoral (plasma levels of nitric oxide and respiratory burst) parameters were determined at 4 h, 24 h, 48 h, and 14 days post-challenge periods. The control fish were gavaged with distilled water. The bacterial-challenged fish had significantly higher WBC counts, and increased levels of plasma nitric oxide and respiratory burst while the RBC counts and the PCV decreased significantly in the bacterial-challenged fish compared to control. The response of the fish to bacterial challenge is both inoculum size- and duration-dependent. The incubation of C. gariepinus with 5 × 104 CFU/mL inoculums of S. marcescens elicited more effects in the fish compared to the control or 1 × 104 CFU/mL group. The results of this study showed that infection with S. marcescens has the potential to modulate the immune system of the fish with the inflammatory pathways playing an important role in the defense of the fish against bacterial infection. [ABSTRACT FROM AUTHOR]

The aim of the study was to perform a comparative evaluation of the toxic effects of selected botanical and synthetic insecticides on the subterranean termites, Macrotermes subhyalinus. Workers and soldiers of M. subhyalinus were exposed to various concentrations (0, 50, 100, 150 and 200 mg/ml) of the aqueous extracts of six plant materials; Anchomanes difformis (leaf, rhizome), Curcuma longa (rhizome), Tithonia diversifolia (leaf, root), and Zingiber officinale (rhizome) and termites' mortality were monitored at 24, 48, 72 and 96 h post-exposure durations. Similarly, the termites were exposed to 0.001, 0.01, 0.1, and 1 % w/v of four synthetic insecticides; chlorpyrifos, dichlorvos, cypermethrin and cyhalothrin. All the plant materials and synthetic insecticides exhibited termiticidal activity even at the lowest concentration tested. For the plant materials, the LD50 values were highest in the groups treated with T. diversifolia (root) for most of the exposure durations while the LD50 values were lowest in A. difformis (rhizome) group at most of the exposure durations. For the synthetic pesticides, the LD50 values were highest in in the groups treated with dichlorvos for most of the exposure durations while the LD50 values were lowest in cypermethrin group at most of the exposure durations. These data suggest that Anchomanes rhizome has the highest termiticide activity among plant materials while cypermethrin was the most potent of the four synthetic insecticides. The results of the present study indicated that all the screened plant materials produce termiticide activity comparable to those of synthetic termiticides, and are therefore potential candidates for termiticide formulation for incorporation into integrated management of termites. [ABSTRACT FROM AUTHOR]

Bacterial infections have been associated with immune dysfunction and oxidative stress in cultured fish species while essential elements could boost immunity and exhibit antioxidant properties in fish. This study was therefore aimed at determining the effects of pre-treatment with waterborne selenium on humoral immunity and redox status of Clarias gariepinus experimentally challenged with Serratia marcescens. Juveniles C. gariepinus were pre-treated with 50 µg/L selenium for 14 days after which they were challenged with 5 × 103 CFU/mL of S. marcescens via oral gavage for 24 or 48 h. The control fish were not pre-treated with selenium and not challenged with bacteria. Thereafter, fish were sacrificed, blood collected into EDTA bottles for the determination of plasma nitric oxide levels and respiratory burst, and the liver excised for the determination of reduced glutathione, lipid peroxidation, and activities of catalase, superoxide dismutase, and glutathione peroxidase. Fish that were pre-treated with selenium prior to bacterial challenge (Sel + Bact) had decreased levels of nitric oxide and lipid peroxidation but a significant increase in the levels of reduced glutathione (at 48-h post-infection period only) compared to the fish challenged with bacteria without prior selenium pre-treatment (Bact). The respiratory burst and catalase activity decreased significantly in the Sel + Bact group especially at 48-h post-infection period while the activity of glutathione peroxidase increased significantly in the Sel + Bact group (at 24-h post-infection period only) compared to the Bact group. The results from this study showed that infection with S. marcescens is capable of disrupting the immune system and redox homeostasis in C. gariepinus, while pre-treatment with selenium has the ability to improve the physiological status of fish that were challenged with bacteria probably through its antioxidant properties. Highlight: The pre-treatment of Clarias gariepinus to waterborne selenium for 14 days improved the redox homeostasis and innate immunity of fish that were experimentally challenged with the bacterium, Serratia marcescens. [ABSTRACT FROM AUTHOR]

Agrochemicals including cypermethrin (cyp) and thiourea are increasingly being applied in modern agriculture, for pest control and to improve crop yield. However, their usage often results in serious environmental concerns. In this study, juvenile African catfish Clarias gariepinus (Burchell 1822) were exposed to 50 µg/L cyp, 100 µg/L cyp, 0.05% thiourea, 50 µg/L cyp + 0.05% thiourea or 100 µg/L cyp + 0.05% thiourea, in a static renewal for 3 weeks, after which the fish were sacrificed, and the level of reduced glutathione and activities of acid phosphatase, alkaline phosphatase, amylase, protease and lipase were determined in the liver or intestinal homogenates. Also, the histopathology of some sections of the intestine was performed. The control fish were maintained in uncontaminated water (i.e. not exposed to cypermethrin or thiourea). The individual exposure of fish to cypermethrin and thiourea resulted in a significant decrease in the levels of GSH and the activities of most of the enzymes. These effects were more pronounced in fish that were exposed to cypermethrin and thiourea under a co-exposure scenario. The histological analyses of some sections of the intestine also revealed the toxicological effect of these agrochemicals, and their use led to visible intestinal pathologies such as severe erosion of the mucosa layer, faded lamina propria and disintegration of the muscle layer. The results of this study demonstrate that both cypermethrin and thiourea can alter the redox status and nutritional physiology of fish. The greater toxic effects of cypermethrin and thiourea under the co-exposure condition reiterated the potential for interactions and synergistic relationship among toxicants. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is a high production volume chemical that has wide industrial applications, especially as a color developer in thermal papers. The present study focused on the determination of levels of BPA in thermal receipts collected from different locations in Akure, Nigeria, and the estimation of daily intake of BPA through dermal absorption. Thermal receipts were collected from different locations, and the levels of extracted BPA were determined using fluorescence spectroscopy. The daily intake of BPA was estimated, and the amount was compared with the reference value. BPA was detected in all the samples analyzed with levels ranging from 1.50 to 3.16 mg/g. These values were lower than the values detected in thermal receipts obtained from other countries. The estimated mean daily intakes of BPA by dermal absorption due to handling of thermal receipts were 0.20 and 9.89 μg/day for the general population and the occupationally exposed individuals, respectively, and were much lower than the reference value of 50 μg/kg bw/day provided by the European Food Safety Authority. This indicates that dermal exposure to BPA is not a serious health risk to the population. [ABSTRACT FROM AUTHOR]

Metallic nanoparticles such as silver (Ag NPs) and iron oxide (Fe3O4 NPs) nanoparticles are high production volume materials due to their applications in various consumer products, and in nanomedicine. However, their inherent toxicities to human cells remain a challenge. The present study was aimed at combining lipidomics data with common phenotypically-based toxicological assays to gain better understanding into cellular response to Ag NPs and Fe3O4 NPs exposure. HepG2 cells were exposed to different concentrations (3.125, 6.25, 12.5, 25, 50 and 100 µg/ml) of the nanoparticles for 24 h, after which they were assayed for toxic effects using toxicological assays like cytotoxicity, mutagenicity, apoptosis and oxidative stress. The cell membrane phospholipid profile of the cells was also performed using shotgun tandem mass spectrometry. The results showed that nanoparticles exposure resulted in concentration-dependent cytotoxicity as well as reduced cytokinesis-block proliferation index (CBPI). Also, there was an increase in the production of ROS and superoxide anions in exposed cells compared to the negative control. The lipidomics data revealed that nanoparticles exposure caused a modulation of the phospholipidome of the cells. A total of 155 lipid species were identified, out of which the fold changes of 23 were significant. The high number of differentially changed phosphatidylcholine species could be an indication that inflammation is one of the major mechanisms of toxicity of the nanoparticles to the cells. [ABSTRACT FROM AUTHOR]

Anchomanes difformis is a rhizomatous herb that is commonly used in traditional medicine for the treatment of various diseases. However, there are reports of its toxicity to animals at certain concentrations. The present study was therefore designed to study the potential toxic effects of A. difformis on the liver and kidney of Wistar rats by using various biochemical indices and histopathology. The rats were divided into five groups (I-V) and were treated as follows: group I (negative control); groups II, III, and IV had 1, 2.5, and 5% of A. difformis respectively included in their diets; and group V (positive control) had 5% permethrin in their diets. The experimental treatment lasted 30 days after which the animals were sacrificed, and the blood collected for the determination of serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, and creatinine. The liver and kidney were excised for histopathological and biochemical analyses. The serum levels of AST, ALT, ALP, urea, and creatinine were significantly higher in rats that were maintained on diets that contained 5% A. difformis and 5% permethrin compared to those maintained on basal diets, 1 or 2.5% A. difformis. On the other hand, the liver and kidney levels of AST, ALT, ALP, urea, and creatinine were significantly lower in rats that were maintained on diets that contained 5% A. difformis and 5% permethrin compared to those maintained on basal diets, 1 or 2.5% A. difformis. Also, maintenance of rats on diets that contained 5% A. difformis and 5% permethrin resulted in apparent damage to the liver and kidney. This study has shown the level of safety of A. difformis on mammals; it is both hepatotoxic and nephrotoxic at high levels; therefore, caution must be applied when using the plant as herbal medicine. [ABSTRACT FROM AUTHOR]

Clarias gariepinus were challenged with one of the following treatments: 1 × 10 colony-forming units (CFU)/ml of Escherichia coli (EC1), 2 × 10 CFU/ml of E. coli (EC2), 1 × 10 CFU/ml of Vibrio fischeri (V1), 2 × 10 CFU/ml of V. fischeri (V2), gavaged with distilled water (CW), and not gavaged (C). Fish inoculation with bacteria was done via oral gavage. Fish were maintained in the laboratory for 7 days after the bacterial inoculation, after which various hematological parameters such as percentage packed cell volume (PCV), percentage red blood cell lysis, white blood cell (WBC) counts, and differential white blood cell counts (neutrophils, lymphocytes, monocytes, and eosinophils) were determined. Fish challenged with bacteria have a significantly reduced percentage PCV but a significantly higher percentage of red blood cell lysis, WBC counts, neutrophils, lymphocytes, monocytes, and eosinophils compared to the controls. In all cases, effects tend to be strongly dependent on the CFU of the bacteria with effects generally more pronounced in fish infected with 2 × 10 CFU/ml of either E. coli or V. fischeri. The results of this study indicate that the health status of C. gariepinus is seriously compromised by bacterial infection, and hematological parameters are reliable enough in the assessment and quick diagnosis of the health status of fish infected with bacteria. [ABSTRACT FROM AUTHOR]

In this study, juvenile catfish ( Clarias gariepinus) were exposed to 2 mg/L Pb, 0.5 μg/L cypermethrin, or both for 96 h. Survival ranged from 100 % in both treatments without cypermethrin, to 50 % in fish exposed to cypermethrin only or the mixture. There were significant decreases in liver lysozyme, γ-glutamyl transpeptidase, and alanine aminotransferase activities in fish exposed to cypermethrin or the mixture. Liver aspartate aminotransferase activity (AST) showed a significant reduction after exposure to Pb or cypermethrin alone, and the effect of the mixture on AST was additive or potentially synergistic. Liver lipid peroxidation (LPO) was increased in fish exposed to the mixture compared to those exposed to cypermethrin only, indicating that Pb presence enhanced LPO caused by cypermethrin. Our study demonstrates the potential for toxic interaction between Pb and cypermethrin in fish and suggests that due to the varying responses to contaminant mixtures in our study, researchers should consider using a variety of biomarkers. [ABSTRACT FROM AUTHOR]

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Background: The potential toxicity of clove, Syzygium aromaticum, notwithstanding its beneficial health effect to human health remains a critical issue. Purpose: This study was designed to assess the effects of oil extracts of clove (S. aromaticum) on reproductive parameters in Wistar rats. The ameliorative effect due to co-administration with green tea, Camellia sinensis, was also determined. Methods: Adult rats were exposed via oral gavage to mineral oil (negative control), 5% green tea (GT), 12.5 mg/kg/day chlorpyrifos (CHL, positive control), 360 mg/kg/day clove oil (CO), green tea + chlorpyrifos (GT+CHL), or green tea + clove oil (GT+CO) for 3 weeks, after which the animals were sacrificed and the following sperm parameters: total sperm count, sperm motile count, sperm progressive assessment, and sperm morphology were determined. The serum levels of reproductive hormones, testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH), were determined. The histological sections of the testes were also performed. Results: The results revealed that S. aromaticum treatment resulted in significant damage to the sperm morphology especially at the neck and tail regions with only a marginal change to the total sperm count, sperm motile count, and sperm progressive assessment. The levels of testosterone, FSH, and LH decreased significantly in rats treated with S. aromaticum. Histopathological analyses revealed significant disruption of normal testes structure in rats that were treated with either clove oil or chlorpyrifos. Conclusion: Overall, the results of this study show that the co-administration with C. sinensis has the potential to ameliorate the clove-induced reproductive toxicity in rats. [ABSTRACT FROM AUTHOR]