Evaluation of larvicidal enhanced activity of sandalwood oil via nano-emulsion against Culex pipiens and Ades aegypti

Mosquito control with essential oils is a trending strategy using aqueous oil nano-emulsions to expand their performance. Sandalwood essential oil and its prepared nano-emulsion used to estimate their larvicidal activities against the 3rd instar larvae of Culex pipiens and Aedes aegypti and their effects on larval tissue detoxifying enzymes. Sandalwood nano-emulsion was characterized by homogeneous, stable, average particles size (195.7 nm), polydispersity index (0.342), and zeta potential (?20.1 mV). Morphologically showed a regular spherical shape in size ranged from 112 to 169 nm that confirmed via scanning electron microscopy. Oil analysis identified sesquiterpene alcohols, mainly santalols, terpenoids, aromatic compounds, fatty acid methyl esters, and phenolic compounds. Larvicidal activities of the oil and its nano-emulsion indicated dose, formulation, and exposure time-related mortality after 24 and 48 h in both species. After 24 h, 100% mortality was detected at 1000 ppm for the nano-emulsion with LC₅₀ of 187.23 and 232.18 ppm and at 1500 ppm for the essential oil with an LC₅₀ of 299.47 and 349.59 ppm against the 3rd larvae Cx. pipiens and Ae. aegypti, respectively. Meanwhile, an enhanced significant effect of the nano-emulsion was observed compared to oil exposure in decreasing total protein content and the activities of alkaline phosphatase and β-esterase enzymes, and increasing α-esterase and glutathione S-transferase activities in larval body tissues. Results demonstrated the enhanced larvicidal potential of sandalwood oil nano-emulsion over that of oil. The effect involved alterations in the detoxifying enzymes based on the existing natural active ingredients against Cx. pipiens and Ae. aegypti larvae.     

Efficacy of Nile tilapia (Oreochromis niloticus) juveniles and spinosyns bioinsecticides against aquatic stages of Culex pipiens: An experimental study

The mosquito Culex pipiens is the most widely distributed dipteran species in all regions of Egypt and the principal vector of Wuchereria bancrofti and certain arboviruses in human beings. For controlling C. pipiens vector, biological tools (e.g., larvivorous fish and bioinsecticides) are more potent and safer options to the environment, human beings, and beneficial organisms than chemical pesticides. The efficiency of O. niloticus juveniles as predatory fish species and two bioinsecticides, spinosad 24% and spinetoram 12%, was investigated against the C. pipiens developmental stages in the laboratory. The first trial evaluated the predatory efficacy of small-sized O. niloticus (2.1–2.6 cm; 250–315 mg) and large-sized O. niloticus (2.5–3.2 cm; 250–315 mg) against the 3rd larvae and pupae of C. pipiens. This is the first report in Egypt confirming the predation potential of O. niloticus as efficient predatory fish against the immature C. pipiens. Large-sized O. niloticus predated a greater number of 3rd of C. pipiens larvae and pupae than the small-sized ones. Furthermore, the daily consumption of C. pipiens larvae by small- and large-sized O. niloticus was significantly higher than the pupae. The second trial assessed the toxicity efficacy of spinosad 24% and spinetoram 12% against C. pipiens larvae and pupae. The results confirmed that the tested bioinsecticides showed higher potency toward C. pipiens larvae than pupae after exposure for 24 h and 48 h. Spinosad was more toxic toward 3rd C. pipiens larvae (LC₅₀ = 0.013 and 0.003 mg/L) and pupae (LC₅₀ = 320.69 and 44.28 mg/L) than spinetoram after 24 and 48 h. Herein, O. niloticus juveniles (as promising native predatory fish) and spinosyns bioinsecticides were more effective against C. pipiens in the larval stage than in the pupal stage. In conclusion, Nile tilapia juveniles and biorational compounds, spinosad 24% and spinetoram 12%, might be considered as promising and favorable environmental biological agents for controlling C. pipiens in Egypt. However, further trials are needed to investigate the potential of these agents in the control of this mosquito vector under field conditions.     

Variability of quantitative morphological traits of mosquito larvae in some species of the <Emphasis Type="Italic">Culex pipiens</Emphasis> complex (Diptera,Culicidae)

The variability of 13 larval morphological characteristics in the urban mosquito, Culex pipiens f. molestus and Culex torrentium, was investigated. These species, belonging to the Culex pipiens complex, are characterized by rapid ecological and evolutionary processes following the human-induced environmental changes. A comparison of 4 geographical larval populations of C. pipiens f. molestus and Culex torrentium revealed different rates of divergence of different morphological traits. In the older form in terms of evolutionary development, C. torrentium, the two local populations differed in the structures of the trophic morphological complex characterized by a higher functional trophic load, while the structures with a lower functional load did not differ between the populations. On the contrary, the populations of the younger form, C. pipiens f. molestus, which had recently colonized new urban sites, differed in the structures with a low functional trophic load (some structures of siphon and abdominal segment IX), whereas structures of the trophic morphological complex were similar in different populations. The possible mechanisms of these morphological transformations and their role in the evolution of mosquito larvae are discussed.     

Ultraviolet light-induced oxidative stress: Effects on antioxidant response of Helicoverpa armigera adults

Ultraviolet (UV) light (blacklight), which emits UV in the range of 320-400 nm, has been used worldwide in light trapping of insect pests. In this article, we test the hypothesis that one of the effects of UV light irradiation is to increase oxidative stress on insects. The effects of UV light irradiation on total antioxidant capacity, malondialdehyde (MDA) and protein carbonyl contents and the activities of superoxide dismutase (SOD), catalase (CAT), peroxidases (POX) and glutathione-S-transferase (GST) were investigated in Helicoverpa armigera adults. The adults were exposed to UV light for various time periods (0, 30, 60 and 90 min). We found that exposure to UV light for 30 min resulted in increased total antioxidant capacity, protein carbonyl content and activities of SOD, CAT, POX and GST. When the exposure time lasted for 60 and 90 min, the protein carbonyl content and activities of CAT and GST remained significantly higher than the control. However, the antioxidant capacity and SOD activity returned to control levels, and POX activity decreased at 60 and 90 min. Our results confirm the hypothesis that UV light irradiation increases the level of oxidative stress in H. armigera adults.     

Larvicidal and adulticidal activity of essential oils from plants of the Lamiaceae family against the West Nile virus vector,Culex pipiens (Diptera: Culicidae)

Culex pipiens mosquitoes are the most widely distributed primary vector of the West Nile virus worldwide. Many attempts for investigation of botanical pesticides to avoid the development of pesticide resistance to conventional synthetic pesticides that are recognized as a threat to the diversity of ecosystems. The study aimed to determine the components of three essential oils of Lamiaceae family, lavender (Lavandula angustifolia), peppermint (Mentha piperita L.), and rosemary (Rosmarinus officinalis L.) by gas chromatography-mass spectrometry (GC–MS) analysis. Furthermore, aimed to validate the insecticidal activities of these oils as larvicidal agents against the third instar larvae of Culex pipiens using five different concentrations (62.5, 125, 250, 500, and 1000 ppm) for each oil in five replicates and as an adulticidal agent against approximately three-day-old female adults of Cx. Pipiens using 0.5, 1, 2, 4, and 5% concentrations in three replicates. The results generally showed a dose-related response. At 1000 ppm, rosemary oil showed the highest larvicidal (100%) (LC₅₀, 214.97 ppm), followed by peppermint oil (92.00% mortality and LC₅₀ (269.35 ppm). Lavender oil showed the lowest efficacy with 87.20% mortality and LC₅₀ (301.11 ppm). At 5% oil concentration, the highest knockdown rate at 1 h was recorded for lavender oil (95.55%), followed by peppermint oil (88.89%) and lastly rosemary oil (84.44%). After 24 h, rosemary oil showed the lowest adult mortality rate (88.89%; LC₅₀, 1.44%), while lavender and peppermint oils both showed a 100% mortality rate, with (LC₅₀, 0.81% and 0.91%, respectively). The chemical constituents of the oils consisted of monoterpenes and sesquiterpenes that determined their insecticidal activities against the target insect stage. The study proposed that rosemary essential oil may be useful for the control of Cx. pipiens larvae as part of an integrated water treatment strategy, and lavender and peppermint oils may be used in an integrated plan for adult’s control.     

Accumulation and oxidative stress biomarkers in Japanese flounder larvae and juveniles under chronic cadmium exposure

This study investigated how Cd exposure affected oxidative biomarkers in Japanese flounder, Paralichthys olivaceus, at early life stages (ELS). Fish were exposed to waterborne Cd (0–48 µg L^− 1) from embryonic to juvenile stages for 80 days. Growth, Cd accumulation, activities of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione S-transferase (GST, EC 2.5.1.18), and levels of glutathione (GSH) and lipid peroxidation (LPO) were investigated at three developmental stages. Flounder growth decreased and Cd accumulation increased with increasing Cd concentration. In metamorphosing larvae, CAT and SOD activities were inhibited and GSH level was elevated, while LPO was enhanced by increasing Cd concentrations. CAT and GST activities of settling larvae were inhibited but GSH level was elevated at high Cd concentrations. In juveniles, SOD activity and LPO level were increased but GST activity was inhibited as Cd concentration increased. Antioxidants in flounder at ELS were able to develop ductile responses to defend against oxidative stress, but LPO fatally occurred due to Cd exposure. These biochemical parameters could be used as effective oxidative biomarkers for evaluating Cd contamination and toxicity in marine environments: CAT, SOD, GSH, and LPO for metamorphosing stage; CAT, GSH, and GST for settling stage; and SOD, GST, and LPO for juvenile stage.     

Insecticidal effects of a novel polyherbal formulation (HF7) against Culex pipiens L. (Diptera: Culicidae)

Plant secondary metabolites represent the most efficient and convenient method to control and overcome environmental pollution and insecticidal resistance. This study explored the mosquitocidal activity of the combined extract of seven plants, (HF7) extracted using a Soxhlet extractor against Culex pipiens under laboratory conditions. Exposure of the 3rd instars of Cx. pipiens to HF7 hexane extract resulted in LC₅₀:114.5 μg/mL and LC₉₀:117.0 μg/mL values after 24 h. The ovicidal activities of hexane extract against Cx. pipiens eggs were 21.6%, 48.3%, and 71.6% at 187.5, 93.7, and 46.88 μg/mL, respectively. HF7-treated larvae showed the formation of irregular blebbing of epithelial cells toward the lumen and sloughing into the gut lumen. HF7 extract resulted in 100% adulticidal mortality at the concentration of 3.7 mg/test tube after 30 min of exposure. The IC₅₀ of HF7 extract was 97.03 µg/ml against larvae, at which nuclear and morphological changes were observed. The spectroscopy spectrum of HF7 hexane extract disclosed the presence of 57 different secondary metabolites, among which the dominant compound was eugenol (32.3%). HF7 hexane extract could serve as a botanical insecticide for controlling Cx. pipiens and potentially other mosquito species.     

Enzymatic activities as potential stress biomarkers of two substituted benzene compounds in Propsilocerus akamusi (Diptera: Chironomidae)

Chironomids are a globally distributed family of insects that can serve as biological indicators of environmental pollution. Substituted benzenes are a group of serious environmental pollutants and severely threaten biological and human health. In order to investigate potential stress biomarkers of substituted benzenes, the effects of 4-chlorophenol and p-phenylene diamine on superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), carboxylesterase (CarE), acid phosphatase (ACP) and alkaline phosphatase (ALP) activities of 4th-instar larval Propsilocerus akamusi were investigated. During 48 h exposure to 4-chlorophenol and p-phenylene diamine, the larval CAT, SOD, GST and CarE activities responded to 4-chlorophenol and p-phenylene diamine in a concentration-and time-dependent way. The ACP and ALP activities of larval P. akamusi responded slowly to 4-chlorophenol and p-phenylene diamine, and only the ALP activities were inhibited significantly under the exposure to p-phenylene diamine for 6 and 24 h. These results suggest that CAT, SOD, GST and CarE activities of chironomids can be used as potential stress biomarkers to monitor 4-chlorophenol and p-phenylene diamine pollution.     

Effects of Extremely Low-Frequency Magnetic Field on Caspase Activities and Oxidative Stress Values in Rat Brain

This study was aimed to investigate the effect of extremely low-frequency magnetic field (ELF-MF) on apoptosis and oxidative stress values in the brain of rat. Rats were exposed to 100 and 500 µT ELF-MF, which are the safety standards of public and occupational exposure for 2 h/day for 10 months. Brain tissues were immunohistochemically stained for the active (cleaved) caspase-3 in order to measure the apoptotic index by a semi-quantitative scoring system. In addition, the levels of catalase (CAT), malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidative capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were measured in rat brain. Final score of apoptosis and MPO activity were not significantly different between the groups. CAT activity decreased in both exposure groups (p?<?0.05), while TAC was found to be lower in ELF 500 group than those in ELF-100 and sham groups (p?<?0.05). MDA, TOS, and OSI values were found to be higher in ELF-500 group than those in ELF-100 and sham groups (p?<?0.05). In conclusion, apoptosis was not changed by long-term ELF-MF exposure, while both 100 and 500 µT ELF-MF exposure induced toxic effect in the rat brain by increasing oxidative stress and diminishing antioxidant defense system.     

Insecticidal and developmental inhibitory properties of monoterpenes on Culex pipiens L. (Diptera: Culicidae)

Twelve monoterpenes were evaluated for larvicidal and adulticidal activities towards Culex pipiens. Geraniol and cuminaldehyde were the most toxic monoterpenes to larvae, with LC₅₀ values of 38.6 and 38.9 mg/l after 24 h of treatment, respectively, whereas cuminaldehyde was the most potent compound after 48 h of treatment, followed by geraniol and thymol. In fumigant toxicity experiments, (R)-carvone and geraniol were the most toxic monoterpenes against the adults at all three tested concentrations and after both 24 and 48 h. When tested at sublethal concentrations (0.5 LC₅₀), (R)-carvone, (S)-limonene and cuminaldehyde decreased hatchability, pupation and adult emergence and induced high larval mortality. Our results suggest that geraniol, cuminaldehyde and (R)-carvone are promising toxicants against Culex pipiens and could be useful in the search for new natural insecticides.     

Larvicidal potency of selected xerophytic plant extracts on Culex pipiens (Diptera: Culicidae)

Chemical insecticides released into the environment may have adverse biological effects. Therefore, there is a need for ecofriendly insecticides for mosquito control. Xerophytic plant extracts that may provide more ecofriendly active component were evaluated against Culex pipiens 4th instars. Plant extracts prepared using different solvents with a Soxhlet apparatus and different concentrations were tested against Culex pipiens larvae. The effects were observed at 24 h and 72 h intervals and LD₅₀ and LD₉₀ values determined. Chloroform (CHCl₃) and ethyl acetate (EtOAc) extracts of Althaea ludwigii were the most effective against Cx. pipiens 4^th instars, but were highly dependent on extract concentrations and exposure time. Results suggest that A. ludwigii extracts contain bioactive compounds, such as phenols and saponins, that may provide effective Cx. pipiens larval control. However, the extract was found to be toxic to zebrafish larvae, and may be toxic to other aquatic fauna. Further studies to determine the active components and toxicity to other fauna are needed.     

Antioxidant responses of the pest natural enemy Hylyphantes graminicola (Araneae: Linyphiidae) exposed to short-term heat stress

Temperature is a critical abiotic factor that causes physiological changes in arthropods. However, little is known about the effect of heat stress on the antioxidant responses of Araneae species. Hylyphantes graminicola is a dominant predator in many cropping systems in China. In the present study, the effect of short-term heat stress (36, 38, 40 or 42 °C) on the reactive oxygen species (ROS) levels, the activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], peroxidases [POD] and glutathione-S-transferases GST]), total antioxidant capacity (TAC), malondialdehyde (MDA) concentrations and survival of H. graminicola spiderlings and adults were investigated. The results showed that H. graminicola adults had a significantly higher survival rate compared to spiderlings at 40 °C. The heat stress increased ROS contents in H. graminicola. The SOD, CAT, POD and GST activities increased in spiderlings and adults under heat stress. These data suggest a defensive function for these enzymes in alleviating oxidative damage. Specifically, SOD plays a key role in reducing the high level of superoxide radicals in spiderlings and adults. Moreover, the POD and CAT capabilities for scavenging H₂O₂ in spiderlings were similar, and CAT may play a more important role than POD in scavenging H₂O₂ in adults at 42 °C. The spiderling TAC increased significantly at 40 and 42 °C, and the adult TAC was stable at 36–40 °C but decreased at 42 °C. These data suggest that TAC was insufficient in H. graminicola adults under more severe stress conditions. These results further our understanding of the physiological response of Araneae species exposed to heat stress.     

Antioxidant responses of Propylaea japonica (Coleoptera: Coccinellidae) exposed to high temperature stress

Temperature is one of the most important environmental factors, and is responsible for a variety of physiological stress responses in organisms. Induced thermal stress is associated with elevated reactive oxygen species (ROS) generation leading to oxidative damage. The ladybeetle, Propylaea japonica (Thunberg) (Coleoptera: Coccinellidae), is considered a successful natural enemy because of its tolerance to high temperatures in arid and semi-arid areas in China. In this study, we investigated the effect of high temperatures (35, 37, 39, 41 and 43 °C) on the survival and activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidases (POD), glutathione-S-transferases (GST), and total antioxidant capacity (TAC) as well as malondialdehyde (MDA) concentrations in P. japonica adults. The results indicated that P. japonica adults could not survive at 43 °C. CAT, GST and TAC were significantly increased when compared to the control (25 °C), and this played an important role in the process of antioxidant response to thermal stress. SOD and POD activity, as well as MDA, did not differ significantly at 35 and 37 °C compared to the control; however, there were increased levels of SOD, POD and MDA when the temperature was above 37 °C. These results suggest that thermal stress leads to oxidative stress and antioxidant enzymes play important roles in reducing oxidative damage in P. japonica adults. This study represents the first comprehensive report on the antioxidant defense system in predaceous coccinellids (the third trophic level). The findings provide useful information for predicting population dynamics and understanding the potential for P. japonica as a natural enemy to control pest insects under varied environmental conditions.     

静磁场对小鼠黑色素瘤细胞B16生长和氧化应激的影响

目的:利用小鼠黑色素瘤细胞B16,研究静磁场对肿瘤细胞生长和氧化应激的影响,探讨氧化应激介导静磁场影响肿瘤细胞生长的机制,为磁场在肿瘤疾病的治疗中的应用提供理论依据。方法:采用MTT法测定磁场对B16细胞活力的影响;利用流式细胞仪测定静磁场暴露对B16细胞周期分布的影响;利用生物化学方法测定磁场暴露对细胞氧化防御系统相关蛋白酶活性的影响。结果:24 h内50 m T-200 m T静磁场暴露可以抑制B16生长,但超过24 h的磁场暴露可以促进B16生长;100 m T和200 m T静磁场暴露对B16的细胞周期分布没有影响;B16暴露于100 m T和200 m T静磁场48 h,GST活性和GSH/GSSG水平表现为先上升后下降,SOD活性和T-AOC水平先下降后上升,CAT活性没有受到影响。结论:50 m T-200 m T静磁场可以抑制小鼠黑色素瘤细胞B16的生长,诱导肿瘤细胞产生氧化应激。     

Oxidative Damage Induced by Arsenic in Mice or Rats: A Systematic Review and Meta-Analysis

In this meta-analysis, studies reporting arsenic-induced oxidative damage in mouse models were systematically evaluated to provide a scientific understanding of oxidative stress mechanisms associated with arsenic poisoning. Fifty-eight relevant peer-reviewed publications were identified through exhaustive database searching. Oxidative stress indexes assessed included superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), glutathione-s-transferase (GST), glutathione reductase (GR), oxidized glutathione (GSSG), malondialdehyde (MDA), and reactive oxygen species (ROS). Our meta-analysis showed that arsenic exposure generally suppressed measured levels of the antioxidants, SOD, CAT, GSH, GPx, GST, and GR, but increased levels of the oxidants, GSSG, MDA, and ROS. Arsenic valence was important and GR and MDA levels increased to a significantly (P < 0.05) greater extent upon exposure to As³⁺ than to As⁵⁺. Other factors that contributed to a greater overall oxidative effect from arsenic exposure included intervention time, intervention method, dosage, age of animals, and the sample source from which the indexes were estimated. Our meta-analysis effectively summarized a wide range of studies and detected a positive relationship between arsenic exposure and oxidative damage. These data provide a scientific basis for the prevention and treatment of arsenic poisoning.     

The effects of boric acid-induced oxidative stress on antioxidant enzymes and survivorship in Galleria mellonella

Larvae of the wax moth, Galleria mellonella (L.), were reared from first instar on a diet supplemented with 156, 620, 1,250, or 2,500 ppm boric acid (BA). The content of malondialdehyde (MDA, an oxidative stress indicator), and activities of the antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx)] were determined in the fat body and hemolymph in the 7th instar larvae and newly emerged pupae. Relative to control larvae, MDA was significantly increased in larval hemolymph, larval and pupal fat body, but decreased in the pupal hemolymph. Insects reared on diets with 156- and 620-ppm BA doses yielded increased SOD activity but 1,250- and 2,500-ppm doses resulted in decreased SOD activity in larval hemolymph. SOD activity was significantly increased but CAT was decreased in the larval fat body. High dietary BA treatments led to significantly decreased GST activity. However, they increased GPx activity in larval hemolymph. Dietary BA also affected larval survival. The 1,250- and 2,500-ppm concentrations led to significantly increased larval and pupal mortality and prolonged development. In contrast, the lowest BA concentration increased longevity and shortened development. We infer that BA toxicity is related, at least in part, to oxidative stress management.     

Antioxidant responses of citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae), exposed to thermal stress

Relatively low or high temperatures are responsible for a variety of physiological stress responses in insects and mites. Induced thermal stress was recently associated with increased reactive oxygen species (ROS) generation, which caused oxidative damage. In this study, we examined the time-related effect of the relatively low (0, 5, 10, and 15 °C) or high (32, 35, 38, and 41 °C) temperatures on the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidases (POX), and glutathione-S-transferase (GST), and the total antioxidant capacity (TEAC) of the citrus red mite, Panonychus citri (McGregor). The malondialdehyde (MDA) concentration, as a marker of lipid peroxidation in organisms, was also measured in the citrus red mite under thermal stress conditions. Results showed that SOD and GST activities were significantly increased and play an important role in the process of antioxidant response to thermal stress. Lipid peroxidation levels increased significantly (P < 0.001) and changed in a time-dependent manner. CAT and POX activity, as well as TEAC, did not vary significantly and play a minor role to remove the ROS generation. These results suggest that thermal stress leads to oxidative stress and antioxidant enzymes play an important role in reducing oxidative damage in the citrus red mite.     

Penicillin-induced oxidative stress: effects on antioxidative response of midgut tissues in instars of Galleria mellonella

Penicillin and other antibiotics are routinely incorporated in insect culture media. Although culturing insects in the presence of antibiotics is a decades-old practice, antibiotics can exert deleterious influences on insects. In this article, we test the hypothesis that one of the effects of dietary penicillin is to increase oxidative stress on insects. The effects of penicillin on midgut concentrations of the oxidative stress indicator malondialdehyde (MDA) and on midgut antioxidant enzyme (superoxide dismutase [SOD], catalase [CAT], glutathione S-transferase [GST], and glutathione peroxidase [GPx]) and transaminases (alanine aminotransferase and aspartate aminotransferase) activities in greater wax moth, Galleria mellonella (L.), were investigated. The insects were reared from first instars on artificial diets containing 0.001, 0.01, 0.1, or 1.0 g penicillin per 100 g of diets. MDA content was significantly increased in the midgut tissues of each larval instar reared in the presence of high penicillin concentrations. Activities of antioxidant and transaminase enzymes did not show a consistent pattern with respect to penicillin concentrations in diet or age of larvae. Despite the increased penicillin-induced oxidative stress in gut tissue, antioxidant and transaminase enzymes did not correlate with oxidative stress level or between each other in larvae of other age stages except for the seventh instar. We found a significant negative correlation of MDA content with SOD and GST activities in seventh instars. SOD activity was also negatively correlated with CAT activity in seventh instars. These results suggest that exposure to dietary penicillin resulted in impaired enzymatic antioxidant defense capacity and metabolic functions in wax moth larval midgut tissues and that the resulting oxidative stress impacts midgut digestive physiology.     

Modulatory role of Emblica officinalis fruit extract against arsenic induced oxidative stress in Swiss albino mice

Arsenic, an important human toxin, is naturally occurring in groundwater and its accumulation in plants and animals have assumed a menacing proportion in a large part of the world, particularly Asia. Epidemiological studies have shown a strong association between chronic arsenic exposure and various adverse health effects, including cardiovascular diseases, neurological defects and cancer of lung, skin, bladder, liver and kidney. The protective role of the fruits of Emblica officinalis (500 mg/kg b.wt.) was studied in adult Swiss albino mice against arsenic induced hepatopathy. Arsenic treated group (NaAsO₂, 4 mg/kg b.wt.) had a significant increase in serum transaminases and lipid peroxidation (LPO) content in liver, whereas significant decrease was recorded in hepatic superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) and serum alkaline phosphatase activity. Combined treatment of Emblica and arsenic (pre and post) declined the serum transaminases and LPO content in liver whereas significant increase was noticed in SOD, CAT, GST and serum alkaline phosphatase activities. Liver histopathology showed that Emblica fruit extract had reduced karyolysis, karyorrhexis, necrosis and cytoplasmic vacuolization induced by NaAsO₂ intoxication. Thus it can be concluded that pre- and post-supplementation of E. officinalis fruit extract significantly reduced arsenic induced oxidative stress in liver.     

Are fish in hot water? Effects of warming on oxidative stress metabolism in the commercial species Sparus aurata

Climate change is disturbing marine biological processes, and impacting goods and services provided to society. Physiological studies are a major contributor to the improvement of biological forecasting in the context of climate change. Oxidative stress biomarkers are useful tools to assess the metabolic status and health of organisms, improving management of wild and cultured populations. The aims of this study were to assess the health status and vulnerability of Sparus aurata juveniles toward ocean warming and heat wave events by (1) exposing fish to a thermal ramp from 18 °C until their Critical Thermal Maximum (≈35 °C) and (2) quantifying oxidative stress biomarkers in several organs, i.e. lipid peroxidation (LPO), catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and cytochrome CYP1A. Fish showed signs of oxidative stress in every tissue tested (gills, muscle, liver, brain and intestine), the most affected being muscle and liver, which showed greater increases in LPO. In general, antioxidant enzymes increased their activity: CAT increased in every organ tested, GST increased in every organ except brain (no change) and SOD increased in every organ except intestine (no change) and brain (decrease, probably due to enzyme denaturation). Muscle showed the greatest stress response with a massive increase in GST. Hepatic CYP1A decreased upon warming suggesting that temperature influences detoxifying mechanisms and may affect fish health. These results are significant in the context of climate change and associated impacts on fisheries and aquaculture because over-induction of oxidative stress due to warming can induce health problems, mortality and shortened lifespan.