Biochemical CuSO4 Toxicity in Drosophila melanogaster Depends on Sex and Developmental Stage of Exposure

The dark side of organic farming: Copper sulphate compromises the life history and behaviour of the walking stick insect, Bacillus rossius

Organic farming is considered the most sustainable form of modern soil cultivation. Yet it often relies on the use of chemical compounds that are not necessarily harmless for the surrounding wildlife. In this study, we tested the effects of realistic concentrations of copper sulphate-largely used in organic farming as a fungicide-on ecologically-relevant traits of the walking stick insect Bacillus rossius, a species commonly found in the proximity of cultivated fields across Europe. By using second-generation progeny of wild-caught parthenogenetic females bred in common gardens, we measured the impact of copper sulphate (CuSO4) on both the life-history (body condition, number of eggs, and hatching success) and behavioural traits (activity and maximum vertical speed) of the individuals. We observed strong negative effects of high, realistic concentrations of copper sulphate on most traits within 12 days of exposure, while effects were less evident at lower concentrations of the pollutant. Our results reveal that realistic concentrations of copper sulphate can compromise important traits that regulate both the survival and reproduction of animals in the wild, with such effects that are, however, dose dependent. We suggest that common practices in organic farming require further consideration on their ecological and evolutionary impact on wildlife.

Interplay between diphenyl diselenide and copper: Impact on D. melanogaster survival, behavior, and biochemical parameters

Copper (Cu2+) is a biologically essential element that participates in numerous physiological processes. However, elevated concentrations of copper have been associated with cellular oxidative stress and neurodegenerative diseases. Organo‑selenium compounds such as diphenyl diselenide (DPDS) have in vitro and in vivo antioxidant properties. Hence, we hypothesized that DPDS may modulate the toxicity of Cu2+ in Drosophila melanogaster. The acute effects (4 days of exposure) caused by a high concentration of Cu2+ (3 mM) were studied using endpoints of toxicity such as survival and behavior in D. melanogaster. The potential protective effect of low concentration of DPDS (20 μM) against Cu2+ was also investigated. Adult flies aged 1-5 days post-eclosion (both sexes) were divided into four groups: Control, DPDS (20 μM), CuSO4 (3 mM), and the combined exposure of DPDS (20 μM) and CuSO4 (3 mM). Survival, biochemical, and behavioral parameters were determined. Co-exposure of DPDS and CuSO4 increased acetylcholinesterase (AChE) activity and the generation of reactive oxygen species (ROS as determined by DFCH oxidation). Contrary to our expectation, the co-exposure reduced survival, body weight, locomotion, catalase activity, and cell viability in relation to control group. Taken together, DPDS potentiated the Cu2+ toxicity.

Biological effects of a copper-based fungicide on the fruit fly, Drosophila melanogaster

The increased consumption of pesticides can have a negative environmental impact by increasing the essential metals to toxic levels. Bordasul® is a commonly used fungicide in Brazil and it is composed of 20% Cu, 10% sulfur, and 3.0% calcium. The study of fungicides in vivo in non-target model organisms can predict their environmental impact more broadly. The Drosophila melanogaster is a unique model due to its ease of handling and maintenance. Here, the potential toxicity of Bordasul® was investigated by assessing the development, survival, and behavior of exposed flies. Exposure to Bordasul® impaired the development (p < 0.01) and caused a significant reduction in memory retention (p < 0.05) and locomotor ability (p < 0.001). Fungicides are needed to assure the world's food demand; however, Bordasul® was highly toxic to D. melanogaster. Therefore, Bordasul® may be potentially toxic to non-target invertebrates and new environmentally-safe biofertilizers have to be developed to preserve the biota.

Toxicological and behavioral analyses indicates the safety of a biofertilizer in the non-target D. melanogaster

The demand for food to feed the growing world population has been promoting the indiscriminate use of chemical fertilizers, which can be detrimental to the environment. In order to maintain high crop productivity without damaging the ecosystem, biofertilizers have emerged as alternative to reduce the use of chemical fertilizers. So, environmentally safer biofertilizer can replace the exploitation of more toxic chemical fertilizer. Here, the fly Drosophila melanogaster was used to study the potential toxicity of the biofertilizer Beifort®. Flies were exposed to high concentrations of Beifort® in the diet (1.8 mL/L, 9.0 mL/L and 18 mL/L), and morphological and behavioral endpoints of toxicity were analyzed (development from egg to adult age, flies longevity, climbing performance, memory and learning of an associative learning, larvae digestive tract damage and plasmid DNA break). Beifort® did not modify flies development, survival, digestive track cell damage, locomotor activity or memory. Beifort® did not induce DNA breakage in vitro and had no toxicity to the non-target D. melanogaster after in vivo exposure. Thus, in addition of promoting the sustainable use of agricultural wastes, the exploitation of Beifort® can contribute to decrease the use of chemical fertilizers.

Biological effects of the frequent application of a copper-containing fungicide on the fruit fly Drosophila melanogaster

The increased consumption of pesticides has an environmental impact due to the dispersion of minerals. Bordasul® is a commonly used fungicide composed of 20% Cu, 10% sulfur, and 3.0% calcium to correct its deficiency in plants. The evaluation of fungicide effects in vivo models is designed to assess their impact on the environment more broadly. Drosophila melanogaster offers a unique model due to its ease of handling and maintenance. Here, the effects of Bordasul® were investigated, addressing the development, survival, and behavior of flies. Our findings showed that exposure to Bordasul® prevented the development of flies (p < 0.01). In addition to causing a significant reduction in memory retention (p < 0.05) and locomotion capacity (p < 0.001). Although fungicides are necessary to satisfy the world's food demand, we conclude that Bordasul® is highly toxic, and that safer media, such as biofertilizers, must be developed as effective alternatives.

Insecticidal activity of the organotellurium 2-Phenylethynyl-Butyltellurium on the Drosophila melanogaster model

2-Phenylethynyl-Butyltellurium (PEBT) is a synthetic organotellurium compound that has shown various pharmacological properties on mammals without any signs of toxicity, but its effects on insects have not been reported before. Therefore, the aim of this study was to assess whether acute exposure to PEBT would promote an insecticidal effect against Drosophila melanogaster. The flies were exposed to three concentrations of PEBT (0.325 µmol L-1, 1.300 µmol L-1, and 5.200 µmol L-1) and a control solution (vehicle), using 450 flies per treatment (three repetitions of 150 flies), for 48 hours. Negative geotaxis and open field tests were performed (in vivo) after 24 and 48h, and acetylcholinesterase (AChE) activity was assessed (ex vivo) after 48h. Also, the mortality rate, 50% Lethal Concentration (LC50), 80% Lethal Concentration (LC80), and 95% Lethal Concentration (LC95) were calculated. Our results show that PEBT presented insecticidal activity against Drosophila melanogaster at all tested concentrations, which caused locomotor impairment and increased acetylcholinesterase activity in the flies' heads.

Enhanced olfactory memory detection in trap-design Y-mazes allows the study of imperceptible memory traces in Drosophila

The neural basis of behavior is identified by systematically manipulating the activity of specific neurons and screening for loss or gain of phenotype. Therefore, robust, high-scoring behavioral assays are necessary for determining the neural circuits of novel behaviors. We report a simple Y-maze design for Drosophila olfactory learning and memory assay. Memory scores in our Y-mazes are considerably better and longer-lasting than scores obtained with commonly used T-mazes. Our results suggest that trapping flies to an odor choice in a Y-maze could improve scores. We postulated that the improved scores could reveal previously undetectable memory traces, enabling the study of underlying neural mechanisms. Indeed, we identified unreported protein synthesis-dependent long-term memories (LTMs), reinforced by ingestion of (1) an aversive compound and (2) a sweet but nonnutritious sugar, both 24 h after training. We also used Y-mazes to probe how using a greater reward may change memory dynamics. Our findings predict that a greater sugar reward may extend existing memory traces or reinforce additional novel ones.

Toxic metals that interact with thiol groups and alteration in insect behavior

Toxic metals, such as mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu), are widespread in the biosphere, and human activities have contributed to their continuous release into the ecosystems. Metal-induced toxicity has been extensively studied in mammals; however, the effects of these metals on insects' behavior have been explored to far lesser degree. As the main mechanism of toxicity, the cationic metals, explored in this review, have high affinity for thiol-containing molecules, disrupting the function of several proteins and low-molecular-weight thiol-containing molecules. Existing literature has corroborated that Hg, Pb, Cd, and Cu can disrupt locomotor and mating behaviors, but their effects on insects' memory and learning have yet to be fully characterized. Though field studies on metal-induced toxicity in insects are limited, results from Drosophila melanogaster as an experimental model suggest that insects living in contaminated environments can have behavioral foraging and reproductive deficits, which may cause population decline. In this review, we address the interaction between metals and endogenous thiol groups, with emphasis on alterations in insect behavior.

Molecular physiology of copper in Drosophila melanogaster

In this review, I look at advances made in our understanding of the molecular physiology of copper homeostasis in the vinegar fly Drosophila melanogaster over the past five years, focussing in particular on the most recent 24 months. Firstly, I review publications investigating the physiological and genetic basis of dietary copper toxicity and tolerance, with particular attention paid to the identification of novel transcriptional and post translational regulators of copper homeostasis. Then I hone in on the growing body of evidence linking copper dysregulation with aberrant neuronal development and function.

Is Turkish coffee protects Drosophila melanogaster on cadmium acetate toxicity by promoting antioxidant enzymes?

With their increasing use in today's industry, heavy metals cause biochemical and biophysical changes by affecting the control and regulatory systems of living things. Cadmium (Cd), a heavy metal, spreads to the environment through both natural sources and industrial activities. It is taken into the organism through water, food, skin contact or smoke. Systems and organs of living things are directly or indirectly affected by Cd toxicity. Besides their recreational usage, herbal products such as coffee are preferred in alternative medicine because of their antioxidant, anti-inflammatory, anticancer and antidiabetic effects. Turkish coffee (TK) is a drink rich in flavorings, phenolic compounds and antioxidant compounds. The study evaluated the possible antioxidant role of TK against oxidative stress induced by Cadmium acetate (CdA) in the fat tissues of old-young female individuals of Drosophila melanogaster. The female flies were fed with either a standard diet, or CdA (10-30 mg), or TK (2%), or both (CdA + TK) for 3 and 10 days. Following the completion of the feeding period, the amounts of fatbody and oxidative stress markers (oxidative stress index, malondialdehyde), activities of antioxidant enzymes (Glutathione-S-transferase, Catalase, and Superoxide dismutase) and their levels were measured. Fat body lipid droplets were high in the individuals exposed to high concentrations of CdA. It was determined that lipid droplets decreased but did not significantly alter oxidative stress in the individuals treated with TK (p = 0.05). This article may be of help in terms of the use of TK compounds as antioxidants to evaluate their effects in preventing heavy metal accumulation and stress in the aging process.

Interactions and toxicity of non-essential heavy metals (Cd, Pb and Hg): lessons from Drosophila melanogaster

Some heavy metals are essential in trace amounts, enhancing enzyme functioning and other intracellular molecules. Others are explicitly toxic at low concentrations, increasing the risk of organ-related toxicity. Non-essential metals have similar mechanisms of toxicity to essential metals. These include the modifiable change in oxidation states, interaction with sulfhydryl moieties of proteins and indirect modification of nucleic acids. Ultimately, oxidative stress is generated, and potentiation of damage ensues. The susceptibility, sensitivity, genetic resources, and cellular response of Drosophila melanogaster to heavy metal exposure and toxicity have made this insect appropriate for toxicological studies. In this review, we focus on the toxicological impacts of non-essential metals (Cd, Pb, and Hg) in Drosophila and discuss its cellular and developmental responses to increasing concentrations of these metals. We also suggest current or proposed therapeutic alternatives, as well as dimensions that may improve the studies of non-essential metal biology.

Deploying Viruses against Phytobacteria: Potential Use of Phage Cocktails as a Multifaceted Approach to Combat Resistant Bacterial Plant Pathogens

Plants in nature are under the persistent intimidation of severe microbial diseases, threatening a sustainable food production system. Plant-bacterial pathogens are a major concern in the contemporary era, resulting in reduced plant growth and productivity. Plant antibiotics and chemical-based bactericides have been extensively used to evade plant bacterial diseases. To counteract this pressure, bacteria have evolved an array of resistance mechanisms, including innate and adaptive immune systems. The emergence of resistant bacteria and detrimental consequences of antimicrobial compounds on the environment and human health, accentuates the development of an alternative disease evacuation strategy. The phage cocktail therapy is a multidimensional approach effectively employed for the biocontrol of diverse resistant bacterial infections without affecting the fauna and flora. Phages engage a diverse set of counter defense strategies to undermine wide-ranging anti-phage defense mechanisms of bacterial pathogens. Microbial ecology, evolution, and dynamics of the interactions between phage and plant-bacterial pathogens lead to the engineering of robust phage cocktail therapeutics for the mitigation of devastating phytobacterial diseases. In this review, we highlight the concrete and fundamental determinants in the development and application of phage cocktails and their underlying mechanism, combating resistant plant-bacterial pathogens. Additionally, we provide recent advances in the use of phage cocktail therapy against phytobacteria for the biocontrol of devastating plant diseases.

Combination of donepezil and gallic acid improves antioxidant status and cholinesterases activity in aluminum chloride-induced neurotoxicity in Wistar rats

The present study compared the effect of donepezil only and combination of donepezil and gallic acid on oxidative status and cholinesterase activity in the brain of Wistar rats administered AlCl₃ for 60 days. Twenty-eight rats (180 - 200 g) were arbitrarily distributed into four groups of seven animals apiece. Group 1 served as normal control and received distilled water throughout the study. Group 2 animals received only AlCl₃ throughout the study while animals in groups 3 and 4 were administered donepezil only (10 mg/kg) and combination of donepezil (10 mg/kg) and gallic acid (50 mg/kg), respectively, in addition to AlCl₃. Treatments were administered orally by gavage. At the end of the study, animals were sacrificed and activities of acetylcholinesterase, butyrylcholinesterase, superoxide dismutase (SOD) and catalase as well as levels of malondialdehyde (MDA), total thiol and nitric oxide (NO) were evaluated in the brain. Histopathological study was conducted on the hippocampus of experimental animals. Results showed that AlCl₃ significantly (p < 0.05) increased brain activities of cholinesterases and levels of MDA and NO with a concomitant decrease in total thiol level as well as activities of SOD and catalase. Donepezil only and combination of donepezil and gallic acid reversed these alterations. Also, combination of donepezil and gallic acid significantly (p < 0.05) improved antioxidant status better than donepezil only. It could be concluded that a synergy might exist between gallic acid and donepezil especially in ameliorating oxidative stress associated with AlCl₃-induced neurotoxicity.

Evaluating the Life-History Responses of Adult Invasive (Bithynia tentaculata) and Native (Physa gyrina) Snails Exposed to a Cu-Based Pesticide (EarthTec® QZ)

The faucet snail, Bithynia tentaculata, is an invasive snail that facilitates outbreaks of waterfowl disease in the Upper Mississippi River of the United States. In response, there is interest in identifying strategies that mitigate its population and spread. In this study we assessed the effects of a copper (Cu) molluscicide, EarthTec® QZ, at three concentrations (0, 0.1 and 0.6 mg/L Cu) on adult B. tentaculata and a coexisting native species, Physa gyrina. We found that in the 0.6 mg/L Cu treatment, ~ 68% of B. tentaculata snails remained alive after a 4-day exposure whereas all P. gyrina snails died. In contrast, a majority of both snail species remained alive and active after 4 days in the control and 0.1 mg/L Cu treatments. Although B. tentaculata demonstrated higher survivorship, it bioaccumulated more Cu than P. gyrina. Additionally, examination of B. tentaculata individuals revealed that females tended to exhibit higher mortality than males.

The Effects of Essential and Non-Essential Metal Toxicity in the Drosophila melanogaster Insect Model: A Review

The biological effects of environmental metal contamination are important issues in an industrialized, resource-dependent world. Different metals have different roles in biology and can be classified as essential if they are required by a living organism (e.g., as cofactors), or as non-essential metals if they are not. While essential metal ions have been well studied in many eukaryotic species, less is known about the effects of non-essential metals, even though essential and non-essential metals are often chemically similar and can bind to the same biological ligands. Insects are often exposed to a variety of contaminated environments and associated essential and non-essential metal toxicity, but many questions regarding their response to toxicity remain unanswered. Drosophila melanogaster is an excellent insect model species in which to study the effects of toxic metal due to the extensive experimental and genetic resources available for this species. Here, we review the current understanding of the impact of a suite of essential and non-essential metals (Cu, Fe, Zn, Hg, Pb, Cd, and Ni) on the D. melanogaster metal response system, highlighting the knowledge gaps between essential and non-essential metals in D. melanogaster. This review emphasizes the need to use multiple metals, multiple genetic backgrounds, and both sexes in future studies to help guide future research towards better understanding the effects of metal contamination in general.

Methanol fraction of Ficus mucoso (welw) prevents iron-induced oxidative damage and alters mitochondrial dysfunction in Drosophila melanogaster

The present study investigated the antioxidant and cyto-/mito-protective roles of Methanol Fraction of Ficus mucoso (MFFM) in iron-induced oxidative damage in Drosophila melanogaster. At first, 10-day survival rates were carried out separately on FeSO₄ and MFFM, respectively, after which ameliorative effects of MFFM were investigated on FeSO₄-induced toxicity for 5 days using biochemical and behavioral markers. Additionally, mitochondria were isolated from treated D. melanogaster to assess mitochondrial Permeability Transition (mPT) pore opening. The results showed that FeSO₄ significantly reduced survival rate, total thiol level and activities of catalase and glutathione-S-transferase in D. melanogaster. In addition, treatment with FeSO₄ caused increased generation of H₂O₂, NO (nitrite/nitrates) and acetylcholinesterase (AChE) activity compared with control (p < 0.05). Conversely, MFFM restored FeSO₄-induced inhibition of glutathione-S-transferase and catalase activities, as well as glutathione and total thiol levels. FeSO₄-induced elevation of AChE activity as well as H₂O₂ and NO (nitrites/nitrates) levels were ameliorated by MFFM with improved climbing activity. Interestingly, MFFM prevented FeSO₄-induced mitochondrial Permeability Transition (mPT) pore opening, and elevated mitochondrial ATPase activity and mitochondrial lipid peroxides generation in D. melanogaster. Taken together, our results demonstrated that iron impaired anti-stress defence capacity, altered behavioral functions, increased generation of mitochondrial malondialdehyde and activated opening of the mPT pore in D. melanogaster. Conversely, methanol fraction of F. mucoso protected against iron-induced cyto-/mito-toxic effects. F. mucoso possibly contain bioactive agents which might be useful in the management of disorders associated with oxidative stress induced by iron and or related metals.

Dietary inclusions of Solanum vegetables mitigate aluminum-induced redox and inflammation-related neurotoxicity in Drosophila melanogaster model

BACKGROUND

This study investigated the modulatory capacity of two Solanum green leafy vegetables; S. macrocarpon L. (African eggplant AE) and S. nigrum L. (Black nightshade BN) on dysregulation of some antioxidant, pro-apoptotic, pro-inflammatory-like, acetylcholinesterase gene expression and redox status in the Drosophila melanogaster model of aluminum-induced neurotoxicity.

METHODS

Flies were exposed to AlCl₃ (6.7 mM) alone or in combination with the leaves (0.1 and 1.0%) from both samples in their diet for seven days. Thereafter, the fly heads were rapidly separated, homogenized, and used to assay for reactive oxygen species (ROS), total thiol content, catalase, glutathione-S-transferase (GST), acetylcholinesterase (AChE) activities, and the expression of antioxidant-mediators (Hsp70, catalase, cnc/Nrf2, Jafrac1 and FOXO), acetylcholinesterase (Ace1), pro-apoptotic caspase-like (Dronc) and its regulator (reaper), as well as inflammation-related (NF-kB/Relish) genes.

RESULTS

Results showed that AlCl₃-exposed flies had significantly reduced survival rate which were ameliorated by AlCl₃ also elevated ROS, GST and reduced AChE activities in fly heads while dietary inclusions of AE and BN ameliorated survial rate and oxidative stress in AlCl₃-exposed flies. In addition, Hsp70, Jafrac1, reaper and NF-kҝB/Relish were significantly upregulated in AlCl₃-exposed fly heads, while cnc/Nrf2 and FOXO were significantly downregulated, but catalase, Dronc and Ace were, not significantly modulated. Nevertheless, these impairments in gene expression levels were ameliorated by dietary inclusions of AE and BN during AlCl₃ exposure.

CONCLUSION

These findings showed that dietary inclusions of AE and BN leaves offer protection against Al-induced neurotoxicity in D. melanogaster and thus, could serve as functional foods with neuroprotective properties.

Fungal compound 1-octen-3-ol induces mitochondrial morphological alterations and respiration dysfunctions in Drosophila melanogaster

Fungal volatile organic compounds (VOCs) comprise a group of compounds commonly found in damp or water-damaged indoor places affecting air quality. Indoor fungal pollution is a severe threat to human health, contributing to the onset of allergic diseases. The compound 1-octen-3-ol, known as "mushroom alcohol", is the most abundant VOC and confers the characteristic mold odor. Exposure to 1-octen-3-ol induces inflammatory markers and episodes of allergic rhinitis and conjunctivitis; however, the effects of this compound towards mitochondria are fairly known. The present study aimed to evaluate the effects of 1-octen-3-ol on inflammatory targets and on mitochondrial morphology and bioenergetic rate in D. melanogaster. Drosophilas were exposed by inhalation to 2.5 μL/L and 5 μL/L of 1-octen-3-ol for 24 h. Observation showed a decreasing in the survival and locomotor ability of flies. Superoxide dismutase (SOD) activity was induced whereas Catalase (CAT) activity was inhibited. Analysis of the mitochondria respiration, detected inhibition of complex I and II in the electron transport chain and a decreased bioenergetic rate. Electronic microscopy provided morphological insights of the mitochondrial status in which a disarrangement in mitochondrial cristae profile was observed. 1-Octen-3-ol induced increased activity of caspase 3/7 and ERK phosphorylation. The mRNA relative steady-state levels of p38^MAPK and JNK were down-regulated, whereas NF-κB and p53 were up-regulated. In parallel, nitrite levels were induced in relation to the non-exposed group. These findings point to the mitochondria as a crucial target for the toxicity of 1-octen-3-ol in parallel with activation of pro-inflammatory factors and apoptotic signaling pathway cascade.

D-Penicillamine prolongs survival and lessens copper-induced toxicity in Drosophila melanogaster

D-penicillamine (DPA) is an amino-thiol that has been established as a copper chelating agent for the treatment of Wilson's disease. DPA reacts with metals to form complexes and/or chelates. Here, we investigated the survival rate extension capacity and modulatory role of DPA on Cu²⁺-induced toxicity in Drosophila melanogaster. Adult Wild type (Harwich strain) flies were exposed to Cu²⁺ (1 mM) and/or DPA (50 μM) in the diet for 7 days. Additionally, flies were exposed to acute Cu²⁺ (10 mM) for 24 h, followed by DPA (50 μM) treatment for 4 days. Thereafter, the antioxidant status [total thiol (T-SH) and glutathione (GSH) levels and glutathione S-transferase and catalase activities] as well as hydrogen peroxide (H₂O₂) level and acetylcholinesterase activity were evaluated. The results showed that DPA treatment prolongs the survival rate of D. melanogaster by protecting against Cu²⁺-induced lethality. Further, DPA restored Cu²⁺-induced depletion of T-SH level compared to the control (P < 0.05). DPA also protected against Cu²⁺ (1 mM)-induced inhibition of catalase activity. In addition, DPA ameliorated Cu²⁺-induced elevation of acetylcholinesterase activity in the flies. The study may therefore have health implications in neurodegenerative diseases involving oxidative stress such as Alzheimer's disease.

Copper decreases associative learning and memory in Drosophila melanogaster

Copper is an essential element to all living organisms. Repeated use of metal-enriched chemicals, fertilizers, and organic substances may cause contamination at a large scale. Altered levels of Cu²⁺ may result in harmful effects and can be associated with memory and cognitive dysfunction. Studying simple, genetically tractable organisms such as Drosophila melanogaster, can reveal important data on the neural basis of conditioning. D. melanogaster is an important alternative experimental model to assess the toxic response to metals. In the present study, the effects of copper on flies' development and in learning and memory retention in male and female adult flies were investigated. We paired an odorant to pain perception and observed the aversion behavior over time. Exposure of D. melanogaster eggs to Cu²⁺ increased mortality of larvae, pupae, and adults and decreased memory retention in adults. Moreover, male flies demonstrated to be more susceptible to Cu²⁺ toxicity than females. The results therefore, reinforce the importance of controlling the anthropogenic heavy-metals soil contamination given their hazardous effects to living organisms.

Curcumin attenuates copper-induced oxidative stress and neurotoxicity in Drosophila melanogaster

Curcumin is a hydrophobic polyphenol derived from the rhizome of the Herb Curcuma longa belonging to the family Zingiberaceae. Curcumin possesses antioxidative, anti-inflammatory and anti-depressant-like properties. In this study, we evaluated the rescue role of Curcumin in Copper²⁺-induced toxicity in D. melanogaster. Adult, wild type flies were exposed to Cu²⁺ (1 mM) and/or Curcumin (0.2 and 0.5 mg/kg diet) in the diet for 7 days. The results indicated that Cu²⁺- fed flies had reduced survival compared to the control group. Copper toxicity was also associated with a marked decrease in total thiol (T-SH), as well as catalase and glutathione S-transferase activities, contemporaneous with increased acetylcholinesterase (AChE) activity, nitric oxide (nitrate and nitrite) and dopamine levels. Co-exposure of flies to Cu²⁺ and Curcumin prevented mortality, inhibited AChE activity and restored dopamine to normal levels (p < 0.05). Moreover, Curcumin restored eclosion rates, and the cellular antioxidant status, as well as alleviated the accumulation of nitric oxide level in the flies. Curcumin ameliorated oxidative damage in the flies as evidenced by the survival rates, longevity assay as well as the restoration of antioxidant status. Our findings thus suggest that Curcumin ameliorated Cu²⁺-induced neurotoxicity in D. melanogaster and as such could be considered an effective therapeutic agent in the prevention and treatment of disorders, where oxidative stress is implicated.

Biocontrol of phytobacteria with bacteriophage cocktails

Crop loss due to plant pathogens has provoked renewed interest in bacteriophages as a feasible biocontrol strategy of plant diseases. Phage cocktails in particular present a viable option for broadening the phage host range, limiting the emergence of bacterial resistance while maintaining the lytic activity of the phages. It is therefore important that the design used to formulate a phage cocktail should result in the most effective cocktail against the pathogen. It is also critical that certain factors are considered during the formulation and application of a phage cocktail: their stability, the production time and cost of complex cocktails, the potential impact on untargeted bacteria, the timing of phage application, and the persistence in the plant environment. Continuous monitoring is required to ensure that the efficacy of a cocktail is sustained due to the dynamic nature of phages. Although phage cocktails are considered as a plausible biocontrol strategy of phytobacteria, more research needs to be done to understand the complex interaction between phages and bacteria in the plant environment, and to overcome the technical obstacles. © 2019 Society of Chemical Industry.