Beyond the antipredatory defence: Honey bee venom function as a component of social immunity

Bee products in the fight against Helicobacter pylori and molecular interactions

Gastric or duodenal ulcers can lead to upper gastrointestinal (GI) bleeding. Infection with Helicobacter pylori (H. pylori) is one of the most common infections in the world and can cause both gastric ulcers and gastric cancer. The treatment aims to eradicate H. pylori and treatment with antibiotics has made it possible to cure gastric ulcers. The most common complication of untreated peptic ulcer disease is bleeding (hematemesis, melena, and anemia), while perforation occurs in a smaller proportion of patients. In some individuals, the infection causes mucosal changes with increasing age that lead to atrophy and intestinal metaplasia. It is believed that atrophy and especially intestinal metaplasia are a prerequisite for the most common form of gastric cancer, adenocarcinoma. There is presently a demand for an alternate treatment devoid of the current strategies drawbacks including recurrence, resistance and antibiotic abuse. The current workhighlights the possibility of bee product-based treatments for preventing and eliminating H. pylori infestation. Sci-finder, Google Scholar, PubMed, ScienceDirect, Web of Science, and Scopus were used for literature screening. Terms and keywords, i.e. "helicobacter pylori", "epidemiology", "chemotherapy", "honey", "propolis", "bee venom", "bioactive compounds", and "mechanism of action" were used in the search. Bee products are important alternatives that have been utilized for treating many ailments due to their diverse biochemical and biological characteristics. Various mechanisms, such as direct antibacterial, antioxidant, anti-inflammatory, and wound healing capacities, are proposed to explain the potential effect of bee products against H. pylori. The bee product's metabolites have a role in the adherence of H. pylori to stomach epithelial cells. The disruption of bacterial cell membranes and the inhibition of virulence factors are the two mechanisms behind the bee product's promising therapeutic applications against H. pylori.

Antimicrobial Properties of Hive Products and Their Potential Applications in Human and Veterinary Medicine

Hive products, encompassing honey, propolis, bee venom, royal jelly, and pollen, are recognized for their antimicrobial and therapeutic properties. This review examines their chemical composition, explores their mechanisms of action, and discusses their potential applications in both human and veterinary medicine, particularly in addressing the challenge of antimicrobial resistance. This study utilized a comprehensive literature search strategy, gathering data from Google Scholar, MEDLINE PubMed, SciELO, and SCOPUS databases. Relevant search terms were employed to ensure a thorough retrieval of the pertinent literature. Honey, rich in bioactive compounds such as hydrogen peroxide and methylglyoxal, effectively disrupts biofilms and combats multi-drug-resistant pathogens, showing promise in treating a range of infections. Propolis, with its flavonoids and phenolic acids, demonstrates synergistic effects when used in conjunction with antibiotics. Bee venom, particularly its component melittin, exhibits antibacterial and immunomodulatory properties, although further research is needed to address toxicity concerns. Pollen and royal jelly demonstrate broad-spectrum antimicrobial activity, which is particularly relevant to animal health. Existing pre-clinical and clinical data support the therapeutic potential of these hive products. Hive products represent a vast and largely untapped natural resource for combating antimicrobial resistance and developing sustainable therapies, particularly in the field of veterinary medicine. However, challenges remain due to the inherent variability in their composition and the lack of standardized protocols for their preparation and application. Further research is essential to fully elucidate their mechanisms of action, optimize formulations for enhanced efficacy, and establish standardized protocols to ensure their safe and effective clinical use.

Toxic and essential elements in honeybee venom from Slovakia: Potential health risk to humans

Honeybee venom is one of the natural substances produced by bees (Apis mellifera). Their venom gland produces venom which plays a defensive role. In this study a concentration of macro and trace elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Sb, Se, Sr, Pb and Zn) in foragers' and honeybees' venom was analysed by axial inductively coupled plasma optical emission spectrometry (ICP OES) with good validation parameters to differentiate the element accumulation ability in honeybee venom. Cumulative ability for some elements (As, Al, Ba, Cr, Li, Mo, Pb, and Zn) in bee venom was clearly demonstrated. Oppositely, levels of macro elements (Ca, K, Mg and Na) in venom were several times lower compared to the levels detected in foragers. Moreover, PCA analysis of bee samples showed that Cr was associated with locality Košice, and Cd with locality Krompachy; both have rich industrial history. Since some of analysed elements are potentially toxic for humans, a risk assessment for bee-stung scenario was also calculated. A new way of exposure to potentially toxic elements via honeybee stung was showed in this study. Non-carcinogenic risk assessment for humans to selected toxic elements (As, Cd, Cr, Ni, and Pb) demonstrated acceptable risk and moreover the same we may conclude for potential carcinogenic risk for beekeepers exposed to As, Cd, Ni, and Pb via venom over their whole life.

1 H-NMR revealed pyruvate as a differentially abundant metabolite in the venom glands of Apis cerana and Apis mellifera

As a common defense mechanism in Hymenoptera, bee venom has complex components. Systematic and comprehensive analysis of bee venom components can aid in early evaluation, accurate diagnosis, and protection of organ function in humans in cases of bee stings. To determine the differences in bee venom composition and metabolic pathways between Apis cerana and Apis mellifera, proton nuclear magnetic resonance (1 H-NMR) technology was used to detect the metabolites in venom samples. A total of 74 metabolites were identified and structurally analyzed in the venom of A. cerana and A. mellifera. Differences in the composition and abundance of major components of bee venom from A. cerana and A. mellifera were mapped to four main metabolic pathways: valine, leucine and isoleucine biosynthesis; glycine, serine and threonine metabolism; alanine, aspartate and glutamate metabolism; and the tricarboxylic acid cycle. These findings indicated that the synthesis and metabolic activities of proteins or polypeptides in bee venom glands were different between A. cerana and A. mellifera. Pyruvate was highly activated in 3 selected metabolic pathways in A. mellifera, being much more dominant in A. mellifera venom than in A. cerana venom. These findings indicated that pyruvate in bee venom glands is involved in various life activities, such as biosynthesis and energy metabolism, by acting as a precursor substance or intermediate product.

The genome of the ant Tetramorium bicarinatum reveals a tandem organization of venom peptides genes allowing the prediction of their regulatory and evolutionary profiles

BACKGROUND

Venoms have evolved independently over a hundred times in the animal kingdom to deter predators and/or subdue prey. Venoms are cocktails of various secreted toxins, whose origin and diversification provide an appealing system for evolutionary researchers. Previous studies of the ant venom of Tetramorium bicarinatum revealed several Myrmicitoxin (MYRTX) peptides that gathered into seven precursor families suggesting different evolutionary origins. Analysis of the T. bicarinatum genome enabling further genomic approaches was necessary to understand the processes underlying the evolution of these myrmicitoxins.

RESULTS

Here, we sequenced the genome of Tetramorium bicarinatum and reported the organisation of 44 venom peptide genes (vpg). Of the eleven chromosomes that make up the genome of T. bicarinatum, four carry the vpg which are organized in tandem repeats. This organisation together with the ML evolutionary analysis of vpg sequences, is consistent with evolution by local duplication of ancestral genes for each precursor family. The structure of the vpg into two or three exons is conserved after duplication events while the promoter regions are the least conserved parts of the vpg even for genes with highly identical sequences. This suggests that enhancer sequences were not involved in duplication events, but were recruited from surrounding regions. Expression level analysis revealed that most vpg are highly expressed in venom glands, although one gene or group of genes is much more highly expressed in each family. Finally, the examination of the genomic data revealed that several genes encoding transcription factors (TFs) are highly expressed in the venom glands. The search for binding sites (BS) of these TFs in the vpg promoters revealed hot spots of GATA sites in several vpg families.

CONCLUSION

In this pioneering investigation on ant venom genes, we provide a high-quality assembly genome and the annotation of venom peptide genes that we think can fosters further genomic research to understand the evolutionary history of ant venom biochemistry.

Transcriptomic Responses Underlying the High Virulence of Black Queen Cell Virus and Sacbrood Virus following a Change in Their Mode of Transmission in Honey Bees (Apis mellifera)

BACKGROUND

Over the last two decades, honey bees (Apis mellifera) have suffered high rates of colony losses that have been attributed to a variety of factors, chief among which are viral pathogens, such as deformed wing virus (DWV), whose virulence has increased because of vector-based transmission by the invasive, ectoparasitic varroa mite (Varroa destructor). A shift in the experimental mode of transmission of the black queen cell virus (BQCV) and sacbrood virus (SBV) from fecal/food-oral (direct horizontal) to vector-mediated (indirect horizontal) transmission also results in high virulence and viral titers in pupal and adult honey bees. Agricultural pesticides represent another factor that acts independently or in interaction with pathogens, and they are also thought to cause colony loss. Understanding the molecular mechanisms underlying the higher virulence following a vector-based mode of transmission provides deeper insight into honey bee colony losses, as does determining whether or not host-pathogen interactions are modulated by exposure to pesticides.

METHODS

Through an experimental design with controlled laboratory, we investigated the effects of the modes of transmission of BQCV and SBV (feeding vs. vector-mediated via injection) alone or in combination with chronic exposure to sublethal and field-realistic concentrations of flupyradifurone (FPF), a novel agricultural insecticide, on honey bee survival and transcription responses by using high-throughput RNA sequencing (RNA-seq) analysis.

RESULTS

Co-exposure to viruses via feeding (VF) or injection (VI) and FPF insecticide had no statistically significant interactive effect on their survival compared to, respectively, VF or VI treatments alone. Transcriptomic analysis revealed a distinct difference in the gene expression profiles of bees inoculated with viruses via injection (VI) and exposed to FPF insecticide (VI+FPF). The number of differentially expressed genes (DEGs) at log2 (fold-change) > 2.0 in VI bees (136 genes) or/and VI+FPF insecticide (282 genes) was very high compared to that of VF bees (8 genes) or the VF+FPF insecticide treatment (15 genes). Of these DEGs, the expression in VI and VI+FPF bees of some immune-related genes, such as those for antimicrobial peptides, Ago2, and Dicer, was induced. In short, several genes encoding odorant binding proteins, chemosensory proteins, odor receptors, honey bee venom peptides, and vitellogenin were downregulated in VI and VI+FPF bees.

CONCLUSIONS

Given the importance of these suppressed genes in honey bees' innate immunity, eicosanoid biosynthesis, and olfactory associative function, their inhibition because of the change in the mode of infection with BQCV and SBV to vector-mediated transmission (injection into haemocoel) could explain the high virulence observed in these viruses when they were experimentally injected into hosts. These changes may help explain why other viruses, such as DWV, represent such a threat to colony survival when transmitted by varroa mites.

Pharmacological properties and therapeutic potential of honey bee venom

Honey bee venom (BV) is a valuable product, and has a wide range of biological effects, and its use is rapidly increasing in apitherapy. Therefore, the current study, we reviewed the existing knowledge about BV composition and its numerous pharmacological properties for future research and use. Honey bee venom or apitoxin is produced in the venom gland in the honey bee abdomen. Adult bees use it as a primary colony defense mechanism. It is composed of many biologically active substances including peptides, enzymes, amines, amino acids, phospholipids, minerals, carbohydrates as well as some volatile components. Melittin and phospholipase A₂ are the most important components of BV, having anti-cancer, antimicrobial, anti-inflammatory, anti-arthritis, anti-nociceptive and other curative potentials. Therefore, in medicine, BV has been used for centuries against different diseases like arthritis, rheumatism, back pain, and various inflammatory infections. Nowadays, BV or its components separately, are used for the treatment of various diseases in different countries as a natural medicine with limited side effects. Consequently, scientists as well as several pharmaceutical companies are trying to get a new understanding about BV, its substances and its activity for more effective use of this natural remedy in modern medicine.

Apis mellifera Venom Inhibits Bacterial and Fungal Pathogens in vitro

<b>Background and Objective:</b> Bacterial and fungal infections are major public health problems. Emerging of drug-resistant microbial strains urges the need for the development of alternative untraditional antimicrobial agents. Bee venom is a rich source of secondary metabolites and antimicrobial agents. In this study, the antimicrobial and antifungal potential of <i>Apis mellifera</i> BV (<i>Am</i>BV) against some medically important bacterial and fungal pathogens was investigated. <b>Materials and Methods:</b> Broth microdilution method and Colony Forming Unit (CFU) assay were used to screen the antibacterial potential of <i>Am</i>BV. Similarly, the antifungal activity of <i>Am</i>BV was evaluated using the agar-well diffusion assay. Moreover, the minimum inhibitory concentration (MIC) values of <i>Am</i>BV against tested microorganisms were determined. <b>Results:</b> <i>Am</i>BV significantly inhibited bacterial and fungal growth. The MIC values of <i>Am</i>BV were 15.625, 31.25, 7.8, 7.8 μg mL<sup></sup><sup>1</sup> against <i>Escherichia coli</i> ATCC 8739, <i>Staphylococcus aureus</i> ATCC 6538P, <i>Serratia marcescens</i> AUH 98 and <i>Streptococcus mutans</i> ATCC 25175, respectively. Similarly, <i>Am</i>BV at concentrations of 300 and 600 μg mL<sup></sup><sup>1</sup> significantly inhibited the growth of <i>Aspergillus niger</i> ATCC 16404, <i>Alternaria alternata</i> MLBM09, <i>Fusarium oxysporum </i>MLBM212 and <i>Aspergillus flavus. </i><b>Conclusion:</b> These results indicated that<i> Am</i>BV could be used in future preclinical and clinical studies to develop cost-effective and efficient antibacterial and antifungal agents. Moreover, this study presents <i>Am</i>BV as an efficient alternative antimicrobial agent against medically important pathogens.

The Honey Bee Apis mellifera: An Insect at the Interface between Human and Ecosystem Health

Simple Summary

Apis mellifera Linnaeus (1758), a honey bee, is a eusocial insect widely known for its role in pollination, an essential ecosystem service for plant biodiversity, and quality of vegetables and fruit products. In addition, honey bees and bee products are valuable bioindicators of pollutants, such as airborne particulate matter, heavy metals, and pesticides. In this review, we explore the provisioning, regulating, and cultural services provided by the honey bee, an insect at the interface between human and ecosystem health.

Abstract

The concept of ecosystem services is widely understood as the services and benefits thatecosystems provide to humans, and they have been categorised into provisioning, regulating, supporting, and cultural services. This article aims to provide an updated overview of the benefits that the honey bee Apis mellifera provides to humans as well as ecosystems. We revised the role of honey bees as pollinators in natural ecosystems to preserve and restore the local biodiversity of wild plants; in agro-ecosystems, this species is widely used to enhance crop yield and quality, meeting the increasing food demand. Beekeeping activity provides humans not only with high-quality food but also with substances used as raw materials and in pharmaceuticals, and in polluted areas, bees convey valuable information on the environmental presence of pollutants and their impact on human and ecosystem health. Finally, the role of the honey bee in symbolic tradition, mysticism, and the cultural values of the bee habitats are also presented. Overall, we suggest that the symbolic value of the honey bee is the most important role played by this insect species, as it may help revitalise and strengthen the intimate and reciprocal relationship between humans and the natural world, avoiding the inaccuracy of considering the ecosystems as mere providers of services to humans.

Armed stem to stinger: a review of the ecological roles of scorpion weapons

Scorpions possess two systems of weapons: the pincers (chelae) and the stinger (telson). These are placed on anatomically and developmentally well separated parts of the body, that is, the oral appendages and at the end of the body axis. The otherwise conserved body plan of scorpions varies most in the shape and relative dimensions of these two weapon systems, both across species and in some cases between the sexes. We review the literature on the ecological function of these two weapon systems in each of three contexts of usage: (i) predation, (ii) defense and (iii) sexual contests. In the latter context, we will also discuss their usage in mating. We first provide a comparative background for each of these contexts of usage by giving examples of other weapon systems from across the animal kingdom. Then, we discuss the pertinent aspects of the anatomy of the weapon systems, particularly those aspects relevant to their functioning in their ecological roles. The literature on the functioning and ecological role of both the chelae and the telson is discussed in detail, again organized by context of usage. Particular emphasis is given on the differences in morphology or usage between species or higher taxonomic groups, or between genders, as such cases are most insightful to understand the roles of each of the two distinct weapon systems of the scorpions and their evolutionary interactions. We aimed to synthesize the literature while minimizing conjecture, but also to point out gaps in the literature and potential future research opportunities.

Resin Use by Stingless Bees: A Review

Stingless bees (Meliponini) are highly social bees that are native to tropical and sub-tropical ecosystems. Resin use is vital to many aspects of stingless bee colony function. Stingless bees use resin to build essential nest structures, repel predators, and kill would-be invaders. Furthermore, resin-derived compounds have been found to enrich the cuticular chemical profiles of many stingless bee species, and resin may play an important role in shaping the microbial communities associated with stingless bees and their nests. Despite its importance for colony function, previous reviews of resin use by stingless bees are lacking. This topic grows increasingly urgent as changes in beekeeping and land use practices occur, potentially diminishing stingless bees' ability to incorporate resin into the nest environment. In this article, we review existing literature on resin use by stingless bees and discuss potential areas of future research.

Histopathological Features of Symptomatic and Asymptomatic Honeybees Naturally Infected by Deformed Wing Virus

Deformed wing virus (DWV) is capable of infecting honeybees at every stage of development causing symptomatic and asymptomatic infections. To date, very little is known about the histopathological lesions caused by the virus. Therefore, 40 honeybee samples were randomly collected from a naturally DWV infected hive and subjected to anatomopathological examination to discriminate between symptomatic (29) and asymptomatic (11) honeybees. Subsequently, 15 honeybee samples were frozen at -80° and analyzed by PCR and RTqPCR to determinate the presence/absence of the virus and the relative viral load, while 25 honeybee samples were analyzed by histopathological techniques. Biomolecular results showed a fragment of the expected size (69bp) of DWV in all samples and the viral load was higher in symptomatic honeybees compared to the asymptomatic group. Histopathological results showed degenerative alterations of the hypopharyngeal glands (19/25) and flight muscles (6/25) in symptomatic samples while 4/25 asymptomatic samples showed an inflammatory response in the midgut and the hemocele. Results suggest a possible pathogenic action of DWV in both symptomatic and asymptomatic honeybees, and a role of the immune response in keeping under control the virus in asymptomatic individuals.

Beehive Products as Antibacterial Agents: A Review

Honeybees are one of the most marvelous and economically beneficial insects. As pollinators, they play a vital role in every aspect of the ecosystem. Beehive products have been used for thousands of years in many cultures for the treatment of various diseases. Their healing properties have been documented in many religious texts like the Noble Quran and the Holy Bible. Honey, bee venom, propolis, pollen and royal jelly all demonstrated a richness in their bioactive compounds which make them effective against a variety of bacterial strains. Furthermore, many studies showed that honey and bee venom work as powerful antibacterial agents against a wide range of bacteria including life-threatening bacteria. Several reports documented the biological activities of honeybee products but none of them emphasized on the antibacterial activity of all beehive products. Therefore, this review aims to highlight the antibacterial activity of honey, bee venom, propolis, pollen and royal jelly, that are produced by honeybees.

Altered feeding behavior and immune competence in paper wasps: A case of parasite manipulation?

Paper wasps (Polistes dominula), parasitized by the strepsipteran Xenos vesparum, are castrated and desert the colony to gather on plants where the parasite mates and releases primary larvae, thus completing its lifecycle. One of these plants is the trumpet creeper Campsis radicans: in a previous study the majority of all wasps collected from this plant were parasitized and focused their foraging activity on C. radicans buds. The unexpected prevalence and unusual feeding strategy prompted us to investigate the influence of this plant on wasp behavior and physiology through a multidisciplinary approach. First, in a series of laboratory bioassays, we observed that parasitized wasps spent more time than non-parasitized ones on fresh C. radicans buds, rich of extra-floral nectaries (EFNs), while the same wasps ignored treated buds that lacked nectar drops. Then, we described the structure and ultra-structure of EFNs secreting cells, compatible with the synthesis of phenolic compounds. Subsequently, we analysed extracts from different bud tissues by HPLC-DAD-MS and found that verbascoside was the most abundant bioactive molecule in those tissues rich in EFNs. Finally, we tested the immune-stimulant properties of verbascoside, as the biochemical nature of this compound indicates it might function as an antibacterial and antioxidant. We measured bacterial clearance in wasps, as a proxy for overall immune competence, and observed that it was enhanced after administration of verbascoside-even more so if the wasp was parasitized. We hypothesize that the parasite manipulates wasp behavior to preferentially feed on C. radicans EFNs, since the bioactive properties of verbascoside likely increase host survival and thus the parasite own fitness.

Antimicrobial Properties of Apis mellifera's Bee Venom

Bee venom (BV) is a rich source of secondary metabolites from honeybees (Apis mellifera L.). It contains a variety of bioactive ingredients including peptides, proteins, enzymes, and volatile metabolites. The compounds contribute to the venom’s observed biological functions as per its anti-inflammatory and anticancer effects. The antimicrobial action of BV has been shown in vitro and in vivo experiments against bacteria, viruses, and fungi. The synergistic therapeutic interactions of BV with antibiotics has been reported. The synergistic effect contributes to a decrease in the loading and maintenance dosage, a decrease in the side effects of chemotherapy, and a decrease in drug resistance. To our knowledge, there have been no reviews on the impact of BV and its antimicrobial constituents thus far. The purpose of this review is to address the antimicrobial properties of BV and its compounds.

Quantitative Measurement of Melittin in Asian Honeybee Venom Using a New Method Including UPLC-QqTOF-MS

Asian honeybee venom is widely used in traditional oriental medicine. Melittin is the main component of Asian honeybee venom. In the present study, an ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QqTOF-MS) method was used for accurate qualitative and quantitative analyses of melittin in Asian honeybee venom. The results showed that the dynamic linear range of melittin was from 0.094 to 20 μg/mL, and the limit of quantification was 0.3125 μg/mL. The spiking recovery of melittin in honeybee venom ranged from 84.88% to 93.05%. Eighteen Asian honeybee venom samples in eighteen batches were collected from two different zones of China, and their melittin contents were measured. The contents of melittin in Asian honeybee venom samples was 33.9–46.23% of dry weight. This method proved a useful tool for the rapid evaluation of the authenticity and quality of Asian honeybee venom in terms of the melittin contents, and will contribute to a broader understanding of Asian honeybee venom.

The Venom Compound N-(3-methylbutyl)acetamide Attracts Several Polistes (Fuscopolistes) Species (Hymenoptera: Vespidae)

Polistes paper wasps in the Fuscopolistes subgenus (Hymenoptera: Vespidae) can be serious pests when they swarm at tall man-made structures. Chemical attractants may be useful to trap such paper wasps when they achieve pest status. Polistes venom has been shown to elicit a variety of behavioral responses in congeneric wasps, making it a source for potential chemical attractants. The compound N-(3-methylbutyl)acetamide is a principal volatile component in the venom of many female vespid wasps, including numerous Polistes species. We report the presence of N-(3-methylbutyl)acetamide in autumn gynes of Polistes metricus Say, Polistes bellicosus Cresson, and Polistes dorsalis (F.), as well as workers of Polistes aurifer (Saussure), P. bellicosus, P. metricus, and P. dorsalis. In field tests conducted in Florida, Georgia, South Carolina, and Washington, N-(3-methylbutyl)acetamide attracted male and female P. aurifer and P. metricus, as well as male P. dorsalis and P. bellicosus. Thus, N-(3-methylbutyl)acetamide may be a useful lure for trapping these paper wasps in pest situations.

The Effect of Diet on the Composition and Stability of Proteins Secreted by Honey Bees in Honey

Honey proteins are essential bee nutrients and antimicrobials that protect honey from microbial spoilage. The majority of the honey proteome includes bee-secreted peptides and proteins, produced in specialised glands; however, bees need to forage actively for nitrogen sources and other basic elements of protein synthesis. Nectar and pollen of different origins can vary significantly in their nutritional composition and other compounds such as plant secondary metabolites. Worker bees producing and ripening honey from nectar might therefore need to adjust protein secretions depending on the quality and specific contents of the starting material. Here, we assessed the impact of different food sources (sugar solutions with different additives) on honey proteome composition and stability, using controlled cage experiments. Honey-like products generated from sugar solution with or without additional protein, or plant secondary metabolites, differed neither in protein quality nor in protein quantity among samples. Storage for 4 weeks prevented protein degradation in most cases, without differences between food sources. The honey-like product proteome included several major royal jelly proteins, alpha-glucosidase and glucose oxidase. As none of the feeding regimes resulted in different protein profiles, we can conclude that worker bees may secrete a constant amount of each bee-specific protein into honey to preserve this highly valuable hive product.

Social-medication in bees: the line between individual and social regulation

We use the term social-medication to describe the deliberate consumption or use of plant compounds by social insects that are detrimental to a pathogen or parasite at the colony level, result in increased inclusive fitness to the colony, and have potential costs either at the individual or colony level in the absence of parasite infection. These criteria for social-medication differ from those for self-medication in that inclusive fitness costs and benefits are distinguished from individual costs and benefits. The consumption of pollen and nectar may be considered a form of social immunity if they help fight infection, resulting in a demonstrated increase in colony health and survival. However, the dietary use of pollen and nectar per se is likely not a form of social-medication unless there is a detriment or cost to their consumption in the absence of parasite infection, such as when they contain phytochemicals that are toxic at certain doses. We provide examples among social bees (bumblebees, stingless bees and honey bees) in which the consumption or use of plant compounds have a demonstrated role in parasite defense and health of the colony. We indicate where more work is needed to distinguish between prophylactic and therapeutic effects of these compounds, and whether the effects are observed at the individual or colony level.

Evolutionary Ecology of Fish Venom: Adaptations and Consequences of Evolving a Venom System

Research on venomous animals has mainly focused on the molecular, biochemical, and pharmacological aspects of venom toxins. However, it is the relatively neglected broader study of evolutionary ecology that is crucial for understanding the biological relevance of venom systems. As fish have convergently evolved venom systems multiple times, it makes them ideal organisms to investigate the evolutionary ecology of venom on a broader scale. This review outlines what is known about how fish venom systems evolved as a result of natural enemy interactions and about the ecological consequences of evolving a venom system. This review will show how research on the evolutionary ecology of venom in fish can aid in understanding the evolutionary ecology of animal venoms more generally. Further, understanding these broad ecological questions can shed more light on the other areas of toxinology, with applications across multiple disciplinary fields.

Arthropod venoms: Biochemistry, ecology and evolution

Comprising of over a million described species of highly diverse invertebrates, Arthropoda is amongst the most successful animal lineages to have colonized aerial, terrestrial, and aquatic domains. Venom, one of the many fascinating traits to have evolved in various members of this phylum, has underpinned their adaptation to diverse habitats. Over millions of years of evolution, arthropods have evolved ingenious ways of delivering venom in their targets for self-defence and predation. The morphological diversity of venom delivery apparatus in arthropods is astounding, and includes extensively modified pedipalps, tail (telson), mouth parts (hypostome), fangs, appendages (maxillulae), proboscis, ovipositor (stinger), and hair (urticating bristles). Recent investigations have also unravelled an astonishing venom biocomplexity with molecular scaffolds being recruited from a multitude of protein families. Venoms are a remarkable bioresource for discovering lead compounds in targeted therapeutics. Several components with prospective applications in the development of advanced lifesaving drugs and environment friendly bio-insecticides have been discovered from arthropod venoms. Despite these fascinating features, the composition, bioactivity, and molecular evolution of venom in several arthropod lineages remains largely understudied. This review highlights the prevalence of venom, its mode of toxic action, and the evolutionary dynamics of venom in Arthropoda, the most speciose phylum in the animal kingdom.

Does the Pollen Diet Influence the Production and Expression of Antimicrobial Peptides in Individual Honey Bees?

We investigated the importance of protein nutrition for honey bee immunity. Different protein diets (monofloral pollen of Helianthus spp., Sinapis spp., Asparagus spp., Castanea spp., a mixture of the four different pollen and the pollen substitute Feedbee^TM) were fed to honey bees in cages ad libitum. After 18 days of feeding, apidaecin 1 isoforms concentration in the thorax were measured using nanoflow liquid chromatography coupled with mass spectrometry. Expression levels of genes, coding for apidaecins and abaecin in the abdomen were determined using quantitative PCR. The results indicate that protein-containing nutrition in adult worker honey bees can trigger certain metabolic responses. Bees without dietary protein showed lower apidaecin 1 isoforms concentrations. The significantly lowest concentration of apidaecin 1 isoforms was found in the group that was fed no pollen diet when compared to Asparagus, Castanea, Helianthus, and Sinapis pollen or the pollen supplement FeedBee^TM. Expression levels of the respective genes were also affected by the protein diets and different expression levels of these two antimicrobial peptides were found. Positive correlation between concentration and gene expression of apidaecins was found. The significance of feeding bees with different protein diets, as well as the importance of pollen nutrition for honey bee immunity is demonstrated.

Characterization of the honeybee venom proteins C1q-like protein and PVF1 and their allergenic potential

Honeybee (Apis mellifera) venom (HBV) represents an ideal model to study the role of particular venom components in allergic reactions in sensitized individuals as well as in the eusociality of Hymenoptera species. The aim of this study was to further characterize the HBV components C1q-like protein (C1q) and PDGF/VEGF-like factor 1 (PVF1). C1q and PVF1 were produced as recombinant proteins in insect cells. Their allergenic properties were examined by determining the level of specific IgE antibodies in the sera of HBV-allergic patients (n = 26) as well as by their capacity to activate patients' basophils (n = 11). Moreover, the transcript heterogeneity of PVF1 was analyzed. It could be demonstrated that at least three PVF1 variants are present in the venom gland, which all result from alternative splicing of one transcript. Additionally, recombinant C1q and PVF1 from Spodoptera frugiperda insect cells exhibited specific IgE reactivity with approximately 38.5% of sera of HBV-allergic patients. Interestingly, both proteins were unable to activate basophils of the patients, questioning their role in the context of clinically relevant sensitization. Recombinant C1q and PVF1 can build the basis for a deeper understanding of the molecular mechanisms of Hymenoptera venoms. Moreover, the conflicting results between IgE sensitization and lack of basophil activation, might in the future contribute to the identification of factors that determine the allergenic potential of proteins.

Elucidating the mechanisms underlying the beneficial health effects of dietary pollen on honey bees (Apis mellifera) infested by Varroa mite ectoparasites

Parasites and pathogens of the honey bee (Apis mellifera) are key factors underlying colony losses, which are threatening the beekeeping industry and agriculture as a whole. To control the spread and development of pathogen infections within the colony, honey bees use plant resins with antibiotic activity, but little is known about the properties of other substances, that are mainly used as a foodstuff, for controlling possible diseases both at the individual and colony level. In this study, we tested the hypothesis that pollen is beneficial for honey bees challenged with the parasitic mite Varroa destructor associated to the Deformed Wing Virus. First, we studied the effects of pollen on the survival of infested bees, under laboratory and field conditions, and observed that a pollen rich diet can compensate the deleterious effects of mite parasitization. Subsequently, we characterized the pollen compounds responsible for the observed positive effects. Finally, based on the results of a transcriptomic analysis of parasitized bees fed with pollen or not, we developed a comprehensive framework for interpreting the observed effects of pollen on honey bee health, which incorporates the possible effects on cuticle integrity, energetic metabolism and immune response.

Inducible versus constitutive social immunity: examining effects of colony infection on glucose oxidase and defensin-1 production in honeybees

Honeybees use a variety of defence mechanisms to reduce disease infection and spread throughout the colony. Many of these defences rely on the collective action of multiple individuals to prevent, reduce or eradicate pathogens-often referred to as 'social immunity'. Glucose oxidase (GOX) and some antimicrobial peptides (e.g. defensin-1 or Def1) are secreted by the hypopharyngeal gland of adult bees on larval food for their antiseptic properties. Because workers secrete these compounds to protect larvae, they have been used as 'biomarkers' for social immunity. The aim of this study was to investigate if GOX and Def1 are induced after pathogen exposure to determine whether its production by workers is the result of a collective effort to protect the brood and colony in response to a pathogen challenge. Specifically, we quantified GOX and Def1 in honeybee adults before and after colony-level bacterial infection by American foulbrood ((AFB), Paenibacillus larvae). Overall, our results indicate that levels of GOX and Def1 are not induced in response to pathogenic infections. We therefore conclude that GOX and Def1 are highly constitutive and co-opted as mechanisms of social immunity, and these factors should be considered when investigating immunity at the individual and colony level in social insects.

Effect of Bee Venom and Its Fractions on the Release of Pro-Inflammatory Cytokines in PMA-Differentiated U937 Cells Co-Stimulated with LPS

The venom of Apis mellifera (honey bee) has been reported to play a role in immunotherapy, but existing evidence to support its immuno-modulatory claims is insufficient. Four fractions from whole bee venom (BV) were separated using medium pressure liquid chromatography. Their ability to induce the production of cytokines TNFα, IL-1β and IL-6 in phorbol-12-myristate-13-acetate (PMA)-treated U937 cells was assessed. The levels of the three cytokines produced by stimulation with the four fractions and crude BV without LPS were not significantly different from negative control values. However, co-stimulation of the cells with LPS and Fraction 4 (F-4) induced a 1.6-fold increase in TNF-α level (p < 0.05) compared to LPS alone. Likewise, LPS-induced IL-1β production was significantly synergised in the presence of F-1 (nine-fold), F-2 (six-fold), F-3 (four-fold) and F-4 (two-fold) fractions, but was only slightly enhanced with crude BV (1.5-fold) relative to LPS. Furthermore, the LPS-stimulated production of IL-6 was not significantly increased in cells co-treated with F-2 and F-3, but the organic fraction (F-4) showed an inhibitory effect (p < 0.05) on IL-6 production. The latter was elucidated by NMR spectroscopy and found to contain(Z)-9-eicosen-1-ol. The effects observed with the purified BV fractions were more marked than those obtained with the crude sample.

Seasonal benefits of a natural propolis envelope to honey bee immunity and colony health

Honey bees, as social insects, rely on collective behavioral defenses that produce a colony-level immune phenotype, or social immunity, which in turn impacts the immune response of individuals. One behavioral defense is the collection and deposition of antimicrobial plant resins, or propolis, in the nest. We tested the effect of a naturally constructed propolis envelope within standard beekeeping equipment on the pathogen and parasite load of large field colonies, and on immune system activity, virus and storage protein levels of individual bees over the course of a year. The main effect of the propolis envelope was a decreased and more uniform baseline expression of immune genes in bees during summer and autumn months each year, compared with the immune activity in bees with no propolis envelope in the colony. The most important function of the propolis envelope may be to modulate costly immune system activity. As no differences were found in levels of bacteria, pathogens and parasites between the treatment groups, the propolis envelope may act directly on the immune system, reducing the bees' need to activate the physiologically costly production of humoral immune responses. Colonies with a natural propolis envelope had increased colony strength and vitellogenin levels after surviving the winter in one of the two years of the study, despite the fact that the biological activity of the propolis diminished over the winter. A natural propolis envelope acts as an important antimicrobial layer enshrouding the colony, benefiting individual immunity and ultimately colony health.

High-performance liquid chromatography combined with intrinsic fluorescence detection to analyse melittin in individual honeybee (Apis mellifera) venom sac

Melittin is the major toxin peptide in bee venom, which has diverse biological effects. In the present study, melittin was separated by reverse-phase high-performance liquid chromatography, and was then detected using intrinsic fluorescence signal of tryptophan residue. The accuracy, linearity, limit of quantitation (LOQ), intra-day and inter-day precision of the method were carefully validated in this study. Results indicate that the intrinsic fluorescence signal of melittin has linear range from 0.04μg/mL to 20μg/mL with LOQ of 0.04μg/mL. The recovery range of spiked samples is between 81.93% and 105.25%. The precision results are expressed as relative standard deviation (RSD), which is in the range of 2.1-7.4% for intra-day precision and 6.2-10.8% for inter-day precision. Because of the large linear dynamic range and the high sensitivity, intrinsic fluorescence detection (IFD) can be used for analyzing melittin contents in individual venom sac of honeybee (Apis mellifera). The detected contents of melittin in individual bee venom sac are 0.18±0.25μg for one-day old honeybees (n=30), and 114.98±43.51μg for 25-day old (n=30) honeybees, respectively. Results indicate that there is large bee-to-bee difference in melittin contents. The developed method can be useful for discovering the melittin related honeybee biology information, which might be covered in the complex samples.

Unraveling the venom proteome of the bumblebee (Bombus terrestris) by integrating a combinatorial peptide ligand library approach with FT-ICR MS

Within the Apidae, the largest family of bees with over 5600 described species, the honeybee is the sole species with a well studied venom proteome. So far, only little research has focused on bumblebee venom. Recently, the genome sequence of the European large earth bumblebee (Bombus terrestris) became available and this allowed the first in-depth proteomic analysis of its venom composition. We identified 57 compounds, with 52 of them never described in bumblebee venom. Remarkably, 72% of the detected compounds were found to have a honeybee venom homolog, which reflects the similar defensive function of both venoms and the high degree of homology between both genomes. However, both venoms contain a selection of species-specific toxins, revealing distinct damaging effects that may have evolved in response to species-specific attackers. Further, this study extends the list of potential venom allergens. The availability of both the honeybee and bumblebee venom proteome may help to develop a strategy that solves the current issue of false double sensitivity in allergy diagnosis, which is caused by cross-reactivity between both venoms. A correct diagnosis is important as it is recommended to perform an immunotherapy with venom of the culprit species.

Weak and contradictory effects of self-medication with nectar nicotine by parasitized bumblebees

The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solenaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication , using a series of toxicological, microbiological and behavioural experiments. Caged bees infected with Crithidia bombi [TI1] had a slight preference for sucrose solution laced with the alkaloid and behavioural tests showed that the parasite infection induced an increased consumption of nicotine during foraging activity. When ingested, nicotine delayed the progression of a gut infection in bumblebees by a few days, but dietary nicotine did not clear the infection, and after 10 days the parasite load approached that of control bees. Moreover, when pathogens were exposed to the alkaloid prior to host ingestion the protozoan's viability was not directly affected, suggesting that anti-parasite effects were relatively weak. Nicotine consumption in a single dose did not impose any cost even in food-stressed bees (starved) but the alkaloid had detrimental effects on healthy bees if consistently consumed for weeks. These toxic effects disappeared in infected bees suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the infection. Nonetheless we did not find a benefit of nicotine consumption in terms of life expectancy of infected bees, making these findings difficult to interpret. Our results indicate that caution is warranted in interpreting impacts of plant metabolites on insect parasites and suggest that the conditions under which nicotine consumption provides benefits to either bees or plants remain to be identified. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed.

Exploring the hidden honeybee (Apis mellifera) venom proteome by integrating a combinatorial peptide ligand library approach with FTMS

At present, 30 compounds have been described in the venom of the honeybee, and 16 of them were confirmed by mass spectrometry. Previous studies typically combined 2-D PAGE with MALDI-TOF/TOF MS, a technology which now appears to lack sensitivity to detect additional venom compounds. Here, we report an in-depth study of the honeybee venom proteome using a combinatorial peptide ligand library sample pretreatment to enrich for minor components followed by shotgun LC-FT-ICR MS analysis. This strategy revealed an unexpectedly rich venom composition: in total 102 proteins and peptides were found, with 83 of them never described in bee venom samples before. Based on their predicted function and subcellular location, the proteins could be divided into two groups. A group of 33 putative toxins is proposed to contribute to venom activity by exerting toxic functions or by playing a role in social immunity. The other group, considered as venom trace molecules, appears to be secreted for their functions in the extracellular space, or is unintentionally secreted by the venom gland cells due to insufficient protein recycling or co-secretion with other compounds. In conclusion, our approach allowed to explore the hidden honeybee venom proteome and extended the list of potential venom allergens.

BIOLOGICAL SIGNIFICANCE

This study dug deeper into the complex honeybee venom proteome than ever before by applying a highly performing sample pretreatment and mass spectrometric technology. We present putative biological functions for all identified compounds, largely extending our knowledge of the venom toxicity. In addition, this study offers a long list of potential new venom allergens.

Production of antibacterial peptide from bee venom via a new strategy for heterologous expression

Honey bee is important economic insect that not only pollinates fruits and crops but also provides products with various physiological activities. Bee venom is a functional agent that is widely applied in clinical treatment and pharmacy. Secapin is one of these agents that have a significant role in therapy. The functions of secapin from the bee venom have been documented, but little information is known about its heterologous expression under natural condition. Moreover, few scholars verified experimentally the functions of secapin from bee venom in vitro. In this study, we successfully constructed a heterologous expression vector, which is different from conventional expression system. A transgenic approach was established for transformation of secapin gene from the venom of Apis mellifera carnica (Ac-sec) into the edible fungi, Coprinus cinereus. Ac-sec was encoded by a 234 bp nucleotide that contained a signal peptide domain and two potential phosphorylation sites. The sequence exhibited highly homology with various secapins characterized from honey bee and related species. Southern blot data indicated that Ac-sec was present as single or multiple copy loci in the C. cinereus genome. By co-transformation and double-layer active assay, Ac-sec was expressed successfully in C. cinereus and the antibacterial activity of the recombinants was identified, showing notable antibacterial activities on different bacteria. Although Ac-sec is from the venom of Apidae, phylogenetic analysis demonstrated that Ac-sec was more closely related to that of Vespid than to bee species from Apidae. The molecular characteristics of Ac-sec and the potential roles of small peptides in biology were discussed.

Functional characterization of naturally occurring melittin peptide isoforms in two honey bee species, Apis mellifera and Apis cerana

Insect-derived antimicrobial peptides (AMPs) have diverse effects on antimicrobial properties and pharmacological activities such as anti-inflammation and anticancer properties. Naturally occurring genetic polymorphism have a direct and/or indirect influence on pharmacological effect of AMPs, therefore information on single nucleotide polymorphism (SNP) occurring in natural AMPs provides an important clue to therapeutic applications. Here we identified nucleotide polymorphisms in melittin gene of honey bee populations, which is one of the potent AMP in bee venoms. We found that the novel SNP of melittin gene exists in these two honey bee species, Apis mellifera and Apis cerana. Nine polymorphisms were identified within the coding region of the melittin gene, of which one polymorphism that resulted in serine (Ser) to asparagine (Asp) substitution that can potentially effect on biological activities of melittin peptide. Serine-substituted melittin (Mel-S) showed more cytotoxic effect than asparagine-substituted melittin (Mel-N) against E. coli. Also, Mel-N and Mel-S had different inhibitory effects on the production of inflammatory factors such as IL-6 and TNF-α in BV-2 cells. Moreover, Mel-S showed stronger cytotoxic activities than Mel-N peptide against two human ovarian cancer cell lines. Using carbon nanotube-based transistor, we here characterized that Mel-S interacted with small unilamellar liposomes more strongly than Mel-N. Taken together, our present study demonstrates that there exist different characteristics of the gene frequency and the biological activities of the melittin peptide in two honey bee species, Apis mellifera and A. cerana.

Proteome and phosphoproteome analysis of honeybee (Apis mellifera) venom collected from electrical stimulation and manual extraction of the venom gland

BACKGROUND

Honeybee venom is a complicated defensive toxin that has a wide range of pharmacologically active compounds. Some of these compounds are useful for human therapeutics. There are two major forms of honeybee venom used in pharmacological applications: manually (or reservoir disrupting) extracted glandular venom (GV), and venom extracted through the use of electrical stimulation (ESV). A proteome comparison of these two venom forms and an understanding of the phosphorylation status of ESV, are still very limited. Here, the proteomes of GV and ESV were compared using both gel-based and gel-free proteomics approaches and the phosphoproteome of ESV was determined through the use of TiO2 enrichment.

RESULTS

Of the 43 proteins identified in GV, < 40% were venom toxins, and >60% of the proteins were non-toxic proteins resulting from contamination by gland tissue damage during extraction and bee death. Of the 17 proteins identified in ESV, 14 proteins (>80%) were venom toxic proteins and most of them were found in higher abundance than in GV. Moreover, two novel proteins (dehydrogenase/reductase SDR family member 11-like and histone H2B.3-like) and three novel phosphorylation sites (icarapin (S43), phospholipase A-2 (T145), and apamin (T23)) were identified.

CONCLUSIONS

Our data demonstrate that venom extracted manually is different from venom extracted using ESV, and these differences may be important in their use as pharmacological agents. ESV may be more efficient than GV as a potential pharmacological source because of its higher venom protein content, production efficiency, and without the need to kill honeybee. The three newly identified phosphorylated venom proteins in ESV may elicit a different immune response through the specific recognition of antigenic determinants. The two novel venom proteins extend our proteome coverage of honeybee venom.

Pupal cocoons affect sanitary brood care and limit fungal infections in ant colonies

BACKGROUND

The brood of ants and other social insects is highly susceptible to pathogens, particularly those that penetrate the soft larval and pupal cuticle. We here test whether the presence of a pupal cocoon, which occurs in some ant species but not in others, affects the sanitary brood care and fungal infection patterns after exposure to the entomopathogenic fungus Metarhizium brunneum. We use a) a comparative approach analysing four species with either naked or cocooned pupae and b) a within-species analysis of a single ant species, in which both pupal types co-exist in the same colony.

RESULTS

We found that the presence of a cocoon did not compromise fungal pathogen detection by the ants and that species with cocooned pupae increased brood grooming after pathogen exposure. All tested ant species further removed brood from their nests, which was predominantly expressed towards larvae and naked pupae treated with the live fungal pathogen. In contrast, cocooned pupae exposed to live fungus were not removed at higher rates than cocooned pupae exposed to dead fungus or a sham control. Consistent with this, exposure to the live fungus caused high numbers of infections and fungal outgrowth in larvae and naked pupae, but not in cocooned pupae. Moreover, the ants consistently removed the brood prior to fungal outgrowth, ensuring a clean brood chamber.

CONCLUSION

Our study suggests that the pupal cocoon has a protective effect against fungal infection, causing an adaptive change in sanitary behaviours by the ants. It further demonstrates that brood removal-originally described for honeybees as "hygienic behaviour"-is a widespread sanitary behaviour in ants, which likely has important implications on disease dynamics in social insect colonies.