The primary aim of this study was to analyse the influence of honeybee venom on various aspects of Drosophila melanogaster physiology and to assess the efficacy of adipokinetic hormone (AKH) in mitigating venom toxicity. We examined the harmful effects of venom on the thoracic muscles and central nervous system of Drosophila, as well as the potential use of AKH to counteract these effects. The results demonstrated that envenomation altered AKH levels in the Drosophila CNS, promoted cell metabolism, as evidenced by an increase in citrate synthase activity in muscles, and improved relative cell viability in both organs incubated in vitro. Furthermore, venom treatment reduced the activity of two key antioxidative stress enzymes, superoxide dismutase and catalase, and modified the expression of six genes encoding immune system components (Keap1, Relish, Nox, Eiger, Gadd45, and Domeless) in both organs. The venom also disrupted muscle cell ultrastructure, specifically myofibrils, and increased the release of arginine kinase into the incubation medium. Notably, when administered alongside the venom, AKH influenced the majority of these changes. AKH was the most effective in minimising damage to the ultrastructure of muscle cells and preventing the release of arginine kinase from muscles to the medium; however, in other parameters, the effect was modest or minimal. Given that honeybee venom often affects humans, understanding its actions and potential ways to reduce or eliminate them is valuable and could lead to the development of pharmacologically important compounds that may have clinical relevance.

• Keywords
• Adipokinetic hormone, Arginine kinase, Bee venom, Drosophila model, Immune responsible genes, Muscle structure,
• MeSH
• Central Nervous System drug effects   metabolism   MeSH
• Drosophila melanogaster drug effects   metabolism   MeSH
• Insect Hormones * pharmacology   metabolism   MeSH
• Pyrrolidonecarboxylic Acid * analogs & derivatives   pharmacology   metabolism   MeSH
• Oligopeptides * pharmacology   metabolism   MeSH
• Bee Venoms * toxicity   antagonists & inhibitors   MeSH
• Bees MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• adipokinetic hormone MeSH Browser
• Insect Hormones * MeSH
• Pyrrolidonecarboxylic Acid * MeSH
• Oligopeptides * MeSH
• Bee Venoms * MeSH

Increased levels of reactive oxygen species (ROS) produced during aerobic metabolism in animals can negatively affect the intracellular redox status, cause oxidative stress and interfere with physiological processes in the cells. The antioxidant defence regulates ROS levels by interplaying diverse enzymes and non-enzymatic metabolites. The thioredoxin system, consisting of the enzyme thioredoxin reductase (TrxR), the redox-active protein thioredoxin (Trx) and NADPH, represent a crucial component of antioxidant defence. It is involved in the signalling and regulation of multiple developmental processes, such as cell proliferation or apoptotic death. Insects have evolved unique variations of TrxR, which resemble mammalian enzymes in overall structure and catalytic mechanisms, but the selenocysteine-cysteine pair in the active site is replaced by a cysteine-cysteine pair typical of bacteria. Moreover, the role of the thioredoxin system in insects is indispensable due to the absence of glutathione reductase, an essential enzyme of the glutathione system. However, the functions of the Trx system in insects are still poorly characterised. In the present review, we provide a critical overview of the current knowledge on the insect Trx system, focusing mainly on TrxR's role in the antioxidant and immune system of model insect species.

• Keywords
• Drosophila melanogaster, antioxidant system, honey bee, reactive oxygen species, redox signalling, thioredoxin, thioredoxin reductase,
• Publication type
• Journal Article MeSH
• Review MeSH

Insect vitellogenins are an intriguing class of complex proteins. They primarily serve as a source of energy for the developing embryo in insect eggs. Vitellogenesis is a complex hormonally and neurally controlled process that command synthesis of vitellogenin molecules and ensures their transport from the female fat bodies or ovarial cells into eggs. The representatives of all insect hormones such as juvenile hormones, ecdysteroids, and neurohormones participate in vitellogenesis, but juvenile hormones (most insect species) and ecdysteroids (mostly Diptera) play the most important roles in the process. Strikingly, not only insect females, but also males have been reported to synthesize vitellogenins indicating their further utility in the insect body. Indeed, it has recently been found that vitellogenins perform a variety of biological functions in the insect body. They participate in defense reactions against entomopathogens such as nematodes, fungi, and bacteria, as well as against venoms such as the honeybee Apis mellifera venom. Interestingly, vitellogenins are also present in the venom of the honeybee itself, albeit their exact role is unknown; they most likely increase the efficacy of the venom in the victim's body. Within the bee's body vitellogenins contribute to the lifespan regulation as anti-aging factor acting under tight social interactions and hormonal control. The current minireview covers all of these functions of vitellogenins and portrays them as biologically active substances that play a variety of significant roles in both insect females and males, and not only acting as passive energy sources for developing embryo.

• MeSH
• Ecdysteroids * metabolism   MeSH
• Insecta metabolism   MeSH
• Juvenile Hormones metabolism   MeSH
• Ovary metabolism   MeSH
• Vitellogenins * MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Ecdysteroids * MeSH
• Juvenile Hormones MeSH
• Vitellogenins * MeSH

Reactive oxygen species (ROS) are generated as products of normal cellular metabolic activities; however, the use of pesticides to control leafcutter ants leads to unbalanced ROS production. We evaluated the effects of two insecticides (fipronil, sulfluramid) and metallic insecticide complex (magnesium complex [Mg(hesp)2(phen)] (1)) on the superoxide dismutase (SOD), glutathione (GSH) and the overall antioxidant capacity using two different methodologies: total radical-trapping potential (TRAP) and oxygen radical absorbance capacity (ORAC). Media workers of Atta sexdens (C. Linnaeus) were exposed to the insecticides for 24 h, 48 h, 72 h and 96 h before their fat bodies were dissected for analysis. The results showed that although the sulfluramid may cause the production of ROS, its slow action in the organism does not lead to oxidative stress. There is a rise in oxidative stress in workers of leafcutter ants treated with fipronil because SOD significantly increased when compared to the control group. On the other hand, Mg1-complex suppressed both GSH and SOD, indicating that the immune system may be affected by Mg1-complex, which has a delayed activity ideal for its use in chemical pest control. Both TRAP and ORAC evaluated total antioxidant capacities; however, ORAC proved to be a more sensitive method. In conclusion, the Mg1-complex is a new compound that should be further investigated as a potential replacement for fipronil and sulfluramid in pest control.

• Keywords
• Antioxidant, Fipronil, Flavonoid, Magnesium complex, Sulfluramid,
• MeSH
• Antioxidants MeSH
• Ants * MeSH
• Insecticides * MeSH
• Reactive Oxygen Species MeSH
• Superoxide Dismutase MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• Insecticides * MeSH
• Reactive Oxygen Species MeSH
• sulfluramid MeSH Browser
• Superoxide Dismutase MeSH

Bees originally developed their stinging apparatus and venom against members of their own species from other hives or against predatory insects. Nevertheless, the biological and biochemical response of arthropods to bee venom is not well studied. Thus, in this study, the physiological responses of a model insect species (American cockroach, Periplaneta americana) to honeybee venom were investigated. Bee venom toxins elicited severe stress (LD50 = 1.063 uL venom) resulting in a significant increase in adipokinetic hormones (AKHs) in the cockroach central nervous system and haemolymph. Venom treatment induced a large destruction of muscle cell ultrastructure, especially myofibrils and sarcomeres. Interestingly, co-application of venom with cockroach Peram-CAH-II AKH eliminated this effect. Envenomation modulated the levels of carbohydrates, lipids, and proteins in the haemolymph and the activity of digestive amylases, lipases, and proteases in the midgut. Bee venom significantly reduced vitellogenin levels in females. Dopamine and glutathione (GSH and GSSG) insignificantly increased after venom treatment. However, dopamine levels significantly increased after Peram-CAH-II application and after co-application with bee venom, while GSH and GSSG levels immediately increased after co-application. The results suggest a general reaction of the cockroach body to bee venom and at least a partial involvement of AKHs.

• Keywords
• American cockroach, adipokinetic hormone, dopamine, honey bee, melittin, metabolism, muscle ultrastructure, vitellogenin,
• MeSH
• Central Nervous System chemistry   drug effects   MeSH
• Hemolymph chemistry   drug effects   MeSH
• Insect Hormones pharmacology   MeSH
• Pyrrolidonecarboxylic Acid analogs & derivatives   pharmacology   MeSH
• Oligopeptides pharmacology   MeSH
• Periplaneta chemistry   drug effects   immunology   MeSH
• Immunity, Innate * MeSH
• Bee Venoms adverse effects   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• adipokinetic hormone MeSH Browser
• Insect Hormones MeSH
• Pyrrolidonecarboxylic Acid MeSH
• Oligopeptides MeSH
• Bee Venoms MeSH

Insect adipokinetic hormones (AKHs) are neuropeptides with a wide range of actions, including the control of insect energy metabolism. These hormones are also known to be involved in the insect defence system against toxins and pathogens. In this study, our aim was to demonstrate whether the application of external AKHs significantly enhances the efficacy of the entomopathogenic fungus Isaria fumosorosea in a model species (firebug Pyrrhocoris apterus) and pest species (Egyptian cotton leafworm Spodoptera littoralis and pea aphid Acyrthosiphon pisum). It was found that the co-application of Isaria with AKHs significantly enhanced insect mortality in comparison to the application of Isaria alone. The mode of action probably involves an increase in metabolism that is caused by AKHs (evidenced by the production of carbon dioxide), which accelerates the turnover of Isaria toxins produced into the infected insects. However, several species-specific differences probably exist. Intoxication by Isaria elicited the stimulation of Akh gene expression and synthesis of AKHs. Therefore, all interactions between Isaria and AKH actions as well as their impact on insect physiology from a theoretical and practical point of view need to be discussed further.

• Keywords
• AKH, carbon dioxide production, entomopathogen, insect pest, metabolism, mortality,
• Publication type
• Journal Article MeSH

Despite the increasing number of studies concerning insect immunity, Lutzomyia longipalpis immune responses in the presence of Leishmania infantum chagasi infection has not been widely investigated. The few available studies analyzed the role of the Toll and IMD pathways involved in response against Leishmania and microbial infections. Nevertheless, effector molecules responsible for controlling sand fly infections have not been identified. In the present study we investigated the role a signal transduction pathway, the Transforming Growth Factor-beta (TGF-β) pathway, on the interrelation between L. longipalpis and L. i. chagasi. We identified an L. longipalpis homolog belonging to the multifunctional cytokine TGF-β gene family (LlTGF-β), which is closely related to the activin/inhibin subfamily and potentially involved in responses to infections. We investigated this gene expression through the insect development and in adult flies infected with L. i. chagasi. Our results showed that LlTGF-β was expressed in all L. longipalpis developmental stages and was upregulated at the third day post L. i. chagasi infection, when protein levels were also higher as compared to uninfected insects. At this point blood digestion is finished and parasites are in close contact with the insect gut. In addition, we investigated the role of LlTGF-β on L. longipalpis infection by L. i. chagasi using either gene silencing by RNAi or pathway inactivation by addition of the TGF-β receptor inhibitor SB431542. The blockage of the LlTGF-β pathway increased significantly antimicrobial peptides expression and nitric oxide levels in the insect gut, as expected. Both methods led to a decreased L. i. chagasi infection. Our results show that inactivation of the L. longipalpis TGF-β signal transduction pathway reduce L. i. chagasi survival, therefore suggesting that under natural conditions the parasite benefits from the insect LlTGF-β pathway, as already seen in Plamodium infection of mosquitoes.

• Keywords
• Leishmania, Lutzomyia longipalpis, TGF-β, activin, innate immunity, vector-parasite interaction,
• MeSH
• Survival Analysis MeSH
• Insect Vectors immunology   parasitology   MeSH
• Host-Pathogen Interactions * MeSH
• Leishmania infantum growth & development   MeSH
• Immunity, Innate MeSH
• Psychodidae immunology   parasitology   MeSH
• Signal Transduction MeSH
• Gene Expression Profiling MeSH
• Transforming Growth Factor beta metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Transforming Growth Factor beta MeSH

The impact of disruption of adipokinetic hormone (AKH) signaling was studied during aging in Drosophila in a sexually dimorphic manner. A mutant (Akh1) producing a non-functional AKH peptide was compared with isogenized wild-type controls (w1118), and Akh-rescue line where AKH was ectopically expressed in the mutant background (EE-Akh). Longevity, fecundity, and locomotor activity rhythms remained unaffected by lack of AKH signaling. While the strength of rhythms declined in general with age across all fly lines tested this was more so in case of Akh1 flies. Negative geotaxis was significantly impaired in Akh1 flies. Only young Akh1 flies of both sexes and old Akh1 females showed significantly higher body weight compared to age-matched iso-control flies (except in case of EE-Akh). Expression of genes involved in energy homeostasis and aging indicated that dTOR and Akt expression were elevated in Akh1 flies compared to other genotypes, whereas AMPK and dFoxO expression levels were significantly reduced. Multivariate analysis of the distribution of lipid species revealed a significant accumulation of specific diglyceride (DG) and triglyceride (TG) lipid species, irrespective of sex, attributable in part due to lack of AKH. Moreover, irrespective of lack of AKH, older flies of all genotypes accumulated TGs. Taken together, the results strongly suggest that disruption of AKH has very subtle effects on physiology, behavior and lipid status during aging.

• Keywords
• AKH signaling, adipokinetic hormone, aging, energy homeostasis, lipid status, senescence,
• Publication type
• Journal Article MeSH