Bee Venom Phospholipase A2: Yesterday's Enemy Becomes Today's Friend

Bee Venom and Its Two Main Components-Melittin and Phospholipase A2-As Promising Antiviral Drug Candidates

Viruses are known to infect most types of organisms. In humans, they can cause several diseases that range from mild to severe. Although many antiviral therapies have been developed, viral infections continue to be a leading cause of morbidity and mortality worldwide. Therefore, the discovery of new and effective antiviral agents is desperately needed. Animal venoms are a rich source of bioactive molecules found in natural goods that have been used since ancient times in alternative medicine to treat a variety of human diseases. Recently, and with the onset of the COVID-19 pandemic, scientists have regained their interest in the possible use of natural products, such as bee venom (BV), as a potential antiviral agent to treat viral infections. BV is known to exert many therapeutic activities such as anti-proliferative, anti-bacterial, and anti-inflammatory effects. However, there is limited discussion of the antiviral activity of BV in the literature. Therefore, this review aims to highlight the antiviral properties of BV and its two primary constituents, melittin (MEL) and phospholipase A2 (PLA2), against a variety of enveloped and non-enveloped viruses. Finally, the innovative strategies used to reduce the toxicity of BV and its two compounds for the development of new antiviral treatments are also considered.

Pharmacokinetics and Tissue Distribution of Bee Venom-Derived Phospholipase A2 Using a Sandwich ELISA after Subcutaneous Injection of New Composition Bee Venom in Rats

Bee venom is a traditional drug used to treat the nervous system, musculoskeletal system, and autoimmune diseases. A previous study found that bee venom and one of its components, phospholipase A2, can protect the brain by suppressing neuroinflammation and can also be used to treat Alzheimer's disease. Thus, new composition bee venom (NCBV), which has an increased phospholipase A2 content of up to 76.2%, was developed as a treatment agent for Alzheimer's disease by INISTst (Republic of Korea). The aim of this study was to characterize the pharmacokinetic profiles of phospholipase A2 contained in NCBV in rats. Single subcutaneous administration of NCBV at doses ranging from 0.2 mg/kg to 5 mg/kg was conducted, and pharmacokinetic parameters of bee venom-derived phospholipase A2 (bvPLA2) increased in a dose-dependent manner. Additionally, no accumulation was observed following multiple dosings (0.5 mg/kg/week), and other constituents of NCBV did not affect the pharmacokinetic profile of bvPLA2. After subcutaneous injection of NCBV, the tissue-to-plasma ratios of bvPLA2 for the tested nine tissues were all <1.0, indicating a limited distribution of the bvPLA2 within the tissues. The findings of this study may help understand the pharmacokinetic characteristics of bvPLA2 and provide useful information for the clinical application of NCBV.

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.

Therapeutic Potential of Bee and Scorpion Venom Phospholipase A2 (PLA2): A Narrative Review

Venomous arthropods such as scorpions and bees form one of the important groups with an essential role in medical entomology. Their venom possesses a mixture of diverse compounds, such as peptides, some of which have toxic effects, and enzymatic peptide Phospholipase A2 (PLA2) with a pharmacological potential in the treatment of a wide range of diseases. Bee and scorpion venom PLA2 group III has been used in immunotherapy, the treatment of neurodegenerative and inflammatory diseases. They were assessed for antinociceptive, wound healing, anti-cancer, anti-viral, anti-bacterial, anti-parasitic, and anti-angiogenesis effects. PLA2 has been identified in different species of scorpions and bees. The anti-leishmania, anti-bacterial, anti-viral, and anti-malarial activities of scorpion PLA2 still need further investigation. Many pieces of research have been stopped in the laboratory stage, and several studies need vast investigation in the clinical phase to show the pharmacological potential of PLA2. In this review, the medical significance of PLA2 from the venom of two arthropods, namely bees and scorpions, is discussed.

Phospholipase A2 inhibitor varespladib prevents wasp sting-induced nephrotoxicity in rats

This study aimed to clarify whether varespladib, a phospholipase A₂ (PLA₂) inhibitor, can be used as a therapeutic agent for wasp sting-induced acute kidney injury (AKI). Rats were divided into control, AKI, and AKI + varespladib groups. The AKI model was established by subcutaneously injecting wasp venom at five different sites in rats. Varespladib treatment showed a significant inhibitory effect on wasp venom PLA₂in vitro and in vivo. Moreover, we observed that varespladib decreased the levels of rhabdomyolysis and hemolysis markers compared with that in the AKI group. Histopathological changes in the kidney decreased significantly, and rat serum creatinine levels were reduced after varespladib administration. The significantly regulated genes in the kidney of the AKI group were mostly involved in inflammatory response pathway, and the administration of varespladib remarkably attenuated the expression of these genes. Therefore, varespladib inhibited wasp sting-induced functional and pathological damage to the kidneys. We propose that the PLA₂ inhibitor varespladib protects the kidney tissue in a wasp sting-induced AKI model by inhibiting PLA₂ activity.

Apis mellifera syriaca Venom: Evaluation of Its Anticoagulant Effect, Proteolytic Activity, and Cytotoxicity along with Its Two Main Compounds-MEL and PLA2-On HeLa Cancer Cells

Bee venom (BV) is one of the most remarkable natural products that has been a subject of studies since ancient times. Recent studies have shown that Apis mellifera syriaca venom possesses antibacterial as well as cytotoxic effects on cancer cell lines. The venom contains a variety of bioactive molecules—mainly melittin (MEL) and phospholipase A2 (PLA2), as well as other compounds that are not well characterized. In this work, we continue the biological characterization of A. mellifera syriaca venom by testing its anticoagulant effect on human plasma using the prothrombin time (PT) test, as well as assessing its proteolytic activity. In addition, the cytotoxicity of the crude venom—and of its two main components, MEL and PLA2—was tested on HeLa cancer cell lines for the first time. The results obtained showed the capacity of A. mellifera syriaca venom to increase clotting time, thereby proving its anticoagulant effect. Moreover, the venom did not demonstrate a significant proteolytic activity unless administrated at concentrations ≥ 5 mg/mL. Finally, we showed that crude A. mellifera syriaca venom, along with MEL, exhibit a strong in vitro cytotoxic effect on HeLa cancer cell lines, even at low concentrations. In summary, our findings could serve as a basis for the development of new natural-based drug candidates in the therapeutic field.

New Insights into Potential Beneficial Effects of Bioactive Compounds of Bee Products in Boosting Immunity to Fight COVID-19 Pandemic: Focus on Zinc and Polyphenols

The coronavirus disease 2019 (COVID-19) is an epidemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Populations at risk as well as those who can develop serious complications are people with chronic diseases such as diabetes, hypertension, and the elderly. Severe symptoms of SARS-CoV-2 infection are associated with immune failure and dysfunction. The approach of strengthening immunity may be the right choice in order to save lives. This review aimed to provide an overview of current information revealing the importance of bee products in strengthening the immune system against COVID-19. We highlighted the immunomodulatory and the antiviral effects of zinc and polyphenols, which may actively contribute to improving symptoms and preventing complications caused by COVID-19 and can counteract viral infections. Thus, this review will pave the way for conducting advanced experimental research to evaluate zinc and polyphenols-rich bee products to prevent and reduce the severity of COVID-19 symptoms.

Marine Health-Promoting Compounds: Recent Trends for Their Characterization and Human Applications

Seaweeds represent a rich source of biologically active compounds with several applications, especially in the food, cosmetics, and medical fields. The beneficial effects of marine compounds on health have been increasingly explored, making them an excellent choice for the design of functional foods. When studying marine compounds, several aspects must be considered: extraction, identification and quantification methods, purification steps, and processes to increase their stability. Advanced green techniques have been used to extract these valuable compounds, and chromatographic methods have been developed to identify and quantify them. However, apart from the beneficial effects of seaweeds for human health, these natural sources of bioactive compounds can also accumulate undesirable toxic elements with potential health risks. Applying purification techniques of extracts from seaweeds may mitigate the amount of excessive toxic components, ensuring healthy and safer products for commercialization. Furthermore, limitations such as stability and bioavailability problems, chemical degradation reactions during storage, and sensitivity to oxidation and photo-oxidation, need to be overcome using, for example, nanoencapsulation techniques. Here we summarize recent advances in all steps of marine products identification and purification and highlight selected human applications, including food and feed applications, cosmetic, human health, and fertilizers, among others.

Snake Venom Identification via Fluorescent Discrimination

The identification and discrimination of snake venom are highly desired for timely clinical treatment. However, the complex components in snake venom make it a great challenge to achieve rapid and accurate identification. Inspired by the organism's taste sensing system, a fluorescent sensor array that could differentiate snake venoms was fabricated. The interaction of snake venoms with different fluorescent dyes in the sensor array gave rich information, based on which efficient detection of complex snake venom was achieved. The main six proteins of snake venom in the same concentration, different concentrations, and their mixtures were identified with 100% accuracy. Furthermore, seven snake venoms belonging to different snake families were discriminated in PBS buffer and human plasma. Interferents of bovine serum albumin (BSA), thrombin, and transferrin (TRF) demonstrated the practicability of the fluorescent sensor array. This strategy of a multiresponse sensor array provides an effective method for accurate and rapid venom toxicology analysis, benefiting early and timely clinical diagnosis and treatment.

What do secreted phospholipases A2 have to offer in combat against different viruses up to SARS-CoV-2?

Secreted phospholipases A2 (sPLA2s) form a widespread group of structurally-related enzymes that catalyse the hydrolysis of the sn-2 ester bond of glycerophospholipids to produce free fatty acids and lysophospholipids. In humans, nine catalytically active and two inactive sPLA2 proteins have been identified. These enzymes play diverse biological roles, including host defence against bacteria, parasites and viruses. Several of these endogenous sPLA2s may play a defensive role in viral infections, as they display in vitro antiviral activity by both direct and indirect mechanisms. However, endogenous sPLA2s may also exert an offensive and negative role, dampening the antiviral response or promoting inflammation in animal models of viral infection. Similarly, several exogenous sPLA2s, most of them from snake venoms and other animal venoms, possess in vitro antiviral activities. Thus, both endogenous and exogenous sPLA2s may be exploited for the development of new antiviral substances or as therapeutic targets for antagonistic drugs that may promote a more robust antiviral response. In this review, the antiviral versus proviral role of both endogenous and exogenous sPLA2s against various viruses including coronaviruses is presented. Based on the highlighted developments in this area of research, possible directions of future investigation are envisaged. One of them is also a possibility of exploiting sPLA2s as biological markers of the severity of the Covid-19 pandemic caused by SARS-CoV-2 infection.

Protective Effects of Bee Venom-Derived Phospholipase A2 against Cholestatic Liver Disease in Mice

Hepatocyte apoptosis and inflammation play important roles in cholestatic liver diseases. Bee venom-derived secretory phospholipase A2 (bvPLA2) has been shown to ameliorate various inflammatory diseases. However, whether bvPLA2 has a therapeutic effect against cholestatic liver disease has not been evaluated. Therefore, we investigated the effects of bvPLA2 on cholestatic liver injury and fibrosis in a murine model of 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet feeding. The administration of bvPLA2 ameliorated liver damage, cholestasis, and fibrosis in DDC diet-fed mice, as assessed by serum biochemical tests and histological examinations. In addition, bvPLA2 reduced myofibroblast accumulation, concomitant with suppression of transforming growth factor-β signaling cascade. The administration of bvPLA2 inhibited hepatocyte apoptosis in DDC diet-fed mice as represented by a reduction in the number of cells stained with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and suppression of caspase-3 activation. Moreover, bvPLA2 reduced cytokine production along with the inhibition of the nuclear factor kappa-B pathway. The number of regulatory T-cells was increased by bvPLA2, while the number of other immune cells, including neutrophils, macrophages, and CD8⁺ T-cells, was decreased. Our data indicate that the administration of bvPLA2 ameliorates cholestatic liver injury and fibrosis by inhibiting hepatocyte apoptosis and inflammation.

Molecular characterization of the anticancer properties associated with bee venom and its components in glioblastoma multiforme

Glioblastoma multiforme (GBM) is a frequent form of malignant glioma. Strategic therapeutic approaches to treat this type of brain tumor currently involves a combination of surgery, radiotherapy and chemotherapy. Nevertheless, survival of GBM patients remains in the 12-15 months range following diagnosis. Development of novel therapeutic approaches for this malignancy is therefore of utmost importance. Interestingly, bee venom and its components have shown promising anti-cancer activities in various types of cancer even though information pertaining to GBMs have been limited. The current work was thus undertaken to better characterize the anti-cancer properties of bee venom and its components in Hs683, T98G and U373 human glioma cells. MTT-based cell viability assays revealed IC₅₀ values of 7.12, 15.35 and 7.60 μg/mL for cell lines Hs683, T98G and U373 treated with bee venom, respectively. Furthermore, melittin treatment of these cell lines resulted in IC₅₀ values of 7.77, 31.53 and 12.34 μg/mL, respectively. Cell viability assessment by flow cytometry analysis confirmed signs of late apoptosis and necrosis after only 1 h of treatment with either bee venom or melittin in all three cell lines. Immunoblotting-based quantification of apoptotic markers demonstrated increased expression of Bak and Bax, while Caspsase-3 levels were significantly lower when compared to control cells. Quantification by qRT-PCR showed increased expression levels of long non-coding RNAs RP11-838N2.4 and XIST in glioma cells treated with either bee venom or melittin. Overall, this study provides preliminary insight on molecular mechanisms via which bee venom and its main components can impact viability of glioma cells and warrants further investigation of its anticancer potential in gliomas.

Bee venom reduces burn-induced pain via the suppression of peripheral and central substance P expression in mice

Background

Scalding burn injuries can occur in everyday life but occur more frequently in young children. Therefore, it is important to develop more effective burn treatments.

Objectives

This study examined the effects of bee venom (BV) stimulation on scalding burn injury-induced nociception in mice as a new treatment for burn pain.

Methods

To develop a burn injury model, the right hind paw was immersed temporarily in hot water (65°C, 3 seconds). Immediately after the burn, BV (0.01, 0.02, or 0.1 mg/kg) was injected subcutaneously into the ipsilateral knee area once daily for 14 days. A von Frey test was performed to assess the nociceptive response, and the altered walking parameters were evaluated using an automated gait analysis system. In addition, the peripheral and central expression changes in substance P (Sub P) were measured in the dorsal root ganglion and spinal cord by immunofluorescence.

Results

Repeated BV treatment at the 2 higher doses used in this study (0.02 and 0.1 mg/kg) alleviated the pain responses remarkably and recovered the gait performances to the level of acetaminophen (200 mg/kg, intraperitoneal, once daily), which used as the positive control group. Moreover, BV stimulation had an inhibitory effect on the increased expression of Sub P in the peripheral and central nervous systems by a burn injury.

Conclusions

These results suggest that a peripheral BV treatment may have positive potency in treating burn-induced pain.

Parvovirus Infection in a Child Presenting with Erythema Multiforme and Vasculitis after a Yellow Jacket Bee Sting

Parvovirus B19 has a wide spectrum of clinical manifestations. Erythema multiforme and vasculitis are rarely reported with parvovirus B19 infections. Reactions to insect stings can range from local swelling to life-threatening systemic reactions. There have been rare reports of unusual reactions, such as vasculitis, occurring in a temporal relationship with insect stings. We report an 8-year-old patient having Parvovirus B-19-related erythema multiforme and vasculitis after a yellow jacket bee sting.

Low semen quality and adverse histological changes in testes of adult male mice treated with bee venom (Apis mellifera)

Background

Male infertility has been on the rise since the past seven decades. Recently, in Libya, bee venom therapy (BVT) has become a popular method among alternative healthcare practitioners for treating male infertility. However, a literature search did not find any published studies that investigated the use of BVT for infertility treatment.

Aim

To investigate the effect of bee venom on the male reproductive status through measurements of semen quality parameters and testicular histological changes in adult male mice.

Methods

A total of 48 male mice were randomly divided into three experimental groups (which were subdivided into two subgroups with eight mice each) as follows: control, bee venom sting (BVS), and bee venom injection (BVI). The normal control subgroup mice were not subjected to any treatment, while the vehicle control subgroup mice were injected (i.p.) with 200 μl of 0.9% saline solution. In the BVS-treated subgroups, each mouse was stung by one live bee for five times (BVS-5) or seven times (BVS-7) every third day for 2 or 3 weeks. While each mouse in the BVI-treated subgroups received 23 μg/kg in a dose volume of 200 μl BVIs (i.p.) for five times (BVI-5) or seven times (BVI-7) every third day for 15 or 21 days.

Results

The findings of this study showed that repeated bee venom treatment by sting or injection to adult male mice resulted in a significant decline in testosterone levels, sperm count, sperm motility, and a very significant increase in the percentage of abnormal sperm morphology; also, there were harmful testicular histological changes in the structural organization of seminiferous tubules and degenerative changes in the germinal epithelium compared to control group.

Conclusion

The results of this study provide evidence for the low semen quality and adverse testicular histological changes in male mice treated with bee venom. Hence, there is a desperate need for educating alternative healthcare practitioners and infertile couples about the harmful effects of BVT on reproductive status.

Cell-Penetrating Peptides Derived from Animal Venoms and Toxins

Cell-penetrating peptides (CPPs) comprise a class of short polypeptides that possess the ability to selectively interact with the cytoplasmic membrane of certain cell types, translocate across plasma membranes and accumulate in the cell cytoplasm, organelles (e.g., the nucleus and mitochondria) and other subcellular compartments. CPPs are either of natural origin or de novo designed and synthesized from segments and patches of larger proteins or designed by algorithms. With such intrinsic properties, along with membrane permeation, translocation and cellular uptake properties, CPPs can intracellularly convey diverse substances and nanomaterials, such as hydrophilic organic compounds and drugs, macromolecules (nucleic acids and proteins), nanoparticles (nanocrystals and polyplexes), metals and radionuclides, which can be covalently attached via CPP N- and C-terminals or through preparation of CPP complexes. A cumulative number of studies on animal toxins, primarily isolated from the venom of arthropods and snakes, have revealed the cell-penetrating activities of venom peptides and toxins, which can be harnessed for application in biomedicine and pharmaceutical biotechnology. In this review, I aimed to collate examples of peptides from animal venoms and toxic secretions that possess the ability to penetrate diverse types of cells. These venom CPPs have been chemically or structurally modified to enhance cell selectivity, bioavailability and a range of target applications. Herein, examples are listed and discussed, including cysteine-stabilized and linear, α-helical peptides, with cationic and amphipathic character, from the venom of insects (e.g., melittin, anoplin, mastoparans), arachnids (latarcin, lycosin, chlorotoxin, maurocalcine/imperatoxin homologs and wasabi receptor toxin), fish (pardaxins), amphibian (bombesin) and snakes (crotamine and cathelicidins).

Bee venom phospholipase A2 alleviates collagen-induced polyarthritis by inducing Foxp3+ regulatory T cell polarization in mice

The mechanism underlying bee venom (BV) therapy is still controversial, with opinions ranging from constituent-based pharmacological action to homeopathic-like activity. The purpose of this study was to examine whether BV phospholipase A2 (bvPLA2), an enzymatic component of BV, is a novel anti-inflammatory and anti-arthritic mediator capable of stimulating CD25+ Foxp3+ regulatory T cell (Treg) polarization in a mouse model of human rheumatoid arthritis (RA). An experimental model of RA was established in male DBA/1 mouse by 2-week-interval injections of 100 μg type II collagen emulsified in complete (first injection) or incomplete Freund's adjuvant (second injection) at the base of the tail. During arthritis development, bvPLA2 (0.1, 0.5, 1.0 mg/kg) and/or Treg inhibitors such as anti-CD25 antibodies and peptide 60 (P60) were injected intraperitoneally for 5 weeks. Arthritic symptoms and the expansion of Tregs were then assessed by behavioral assessments, histological and micro-CT imaging, and flow cytometry. bvPLA2 injections significantly alleviated arthritic behaviors such as squeaking and joint swelling, consistent with changes seen on both histological and micro-CT images. The anti-arthritic effects of bvPLA2 were blocked by intraperitoneal injections of 0.25 mg/kg anti-CD25 antibody and 10 μg/kg P60, as determined by behavioral assessments. Flow cytometric analysis of dendritic cells, B cells, and major T cell subsets from spleens revealed a significant depletion of Tregs following anti-CD25 antibody, but not P60, treatment. bvPLA2 treatment exerted significant anti-inflammatory and anti-arthritic activities in a mouse model of RA via the induction of Tregs.

Animal Venom for Medical Usage in Pharmacopuncture in Korean Medicine: Current Status and Clinical Implication

Animal venoms, widespread throughout the world, are complex mixtures, the composition of which depends on the venom-producing species. The objective of this study was to contribute to the development of animal venom-based medicines by investigating the use of animal venom pharmacopuncture in Korean medicine (KM) institutions. We surveyed 256 public health centers from 1 through 31 October 2019 as guided by the Ministry of Health and Welfare (MoHW). A questionnaire developed by an expert group was distributed and collected for statistical analysis. The survey identified three types of animal venom-based pharmacopuncture: bee, snake, and toad venoms. The medications are based on a single animal venom ingredient and produced in 11 external herbal dispensaries (EHDs). Each animal venom is processed, refined, and freeze-dried in a cleanroom to produce a powder formulation that is later measured, diluted, filtered, filled, sealed, sterilized, and packaged as pharmacopuncture injections used in KM institutions. Bee venom therapy is effective in treating musculoskeletal pain, snake venom therapy is effective in controlling bleeding during surgery, and toad venom therapy is effective in cancer treatment. The study suggests that bee, snake, and toad venoms could be used in medical institutions and have the potential for drug development.

Phospholipase A2 enzyme from the venom of Egyptian honey bee Apis mellifera lamarckii with anti-platelet aggregation and anti-coagulation activities

Background

Honey bee venom contains various enzymes with wide medical and pharmaceutical applications.

Results

The phospholipase A2 (PLA2) has been apparently purified from the venom of Egyptian honey bee (Apis mellifera lamarckii) 8.9-fold to a very high specific activity of 6033 U/mg protein using DEAE–cellulose and Sephacryl S-300 columns. The purified bee venom PLA2 is monomeric 16 kDa protein and has isoelectric point (pI) of 5.9. The optimal activity of bee venom PLA2 was attained at pH 8 and 45 °C. Cu²⁺_, Ni²⁺, Fe²⁺_, Ca²⁺, and Co²⁺ exhibited a complete activating effect on it, while Zn²⁺, Mn²⁺, NaN₃, PMSF, N-Methylmaleimide, and EDTA have inhibitory effect.

Conclusions

The purified bee venom PLA2 exhibited anti-platelet aggregation and anti-coagulation activities which makes it promising agent for developing novel anti-clot formation drugs in future.

Bee Venom-A Potential Complementary Medicine Candidate for SARS-CoV-2 Infections

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by severe cytokine storm syndrome following inflammation. SARS-CoV-2 directly interacts with angiotensin-converting enzyme 2 (ACE-2) receptors in the human body. Complementary therapies that impact on expression of IgE and IgG antibodies, including administration of bee venom (BV), have efficacy in the management of arthritis, and Parkinson's disease. A recent epidemiological study in China showed that local beekeepers have a level of immunity against SARS-CoV-2 with and without previous exposure to virus. BV anti-inflammatory properties are associated with melittin and phospholipase A2 (PLA2), both of which show activity against enveloped and non-enveloped viruses, including H1N1 and HIV, with activity mediated through antagonist activity against interleukin-6 (IL-6), IL-8, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α). Melittin is associated with the underexpression of proinflammatory cytokines, including nuclear factor-kappa B (NF-κB), extracellular signal-regulated kinases (ERK1/2), and protein kinase Akt. BV therapy also involves group III secretory phospholipase A₂ in the management of respiratory and neurological diseases. BV activation of the cellular and humoral immune systems should be explored for the application of complementary medicine for the management of SARS-CoV-2 infections. BV "vaccination" is used to immunize against cytomegalovirus and can suppress metastases through the PLA2 and phosphatidylinositol-(3,4)-bisphosphate pathways. That BV shows efficacy for HIV and H1NI offers opportunity as a candidate for complementary therapy for protection against SARS-CoV-2.

Bee Venom: An Updating Review of Its Bioactive Molecules and Its Health Applications

Bee venom (BV) is usually associated with pain since, when humans are stung by bees, local inflammation and even an allergic reaction can be produced. BV has been traditionally used in ancient medicine and in acupuncture. It consists of a mixture of substances, principally of proteins and peptides, including enzymes as well as other types of molecules in a very low concentration. Melittin and phospholipase A2 (PLA2) are the most abundant and studied compounds of BV. Literature of the main biological activities exerted by BV shows that most studies focuses on the comprehension and test of anti-inflammatory effects and its mechanisms of action. Other properties such as antioxidant, antimicrobial, neuroprotective or antitumor effects have also been assessed, both in vitro and in vivo. Moreover, human trials are necessary to confirm those clinical applications. However, notwithstanding the therapeutic potential of BV, there are certain problems regarding its safety and the possible appearance of adverse effects. On this perspective, new approaches have been developed to avoid these complications. This manuscript is aimed at reviewing the actual knowledge on BV components and its associated biological activities as well as the latest advances on this subject.

Toxicological Risk Assessment of the Accidental Ingestion of a Honeybee (Apis mellifera L.) Present in Food

The aim of the present work was to evaluate the possible risk of toxic effects due to the ingestion of a honeybee (Apis mellifera L.) accidentally present in food. The methodology used in this study was a bibliographic survey of studies on the toxic effects related to honeybees, with a critical analysis of the possible risks of accidental ingestion of these insects. The amount of venom present in a bee is considered insufficient to induce detectable toxic effects in a person who ingests it by accident, and various components of the venom are destroyed by gastric secretions. However, despite the rare frequency, there is a risk of the ingestion of a bee, causing an allergic reaction to some components of the venom in sensitized individuals. In addition, pollen carried by a bee may cause an allergic reaction in a sensitive individual. Thus, the accidental ingestion of a bee present in a food does not pose the risk of toxic effects for the majority of the population but may promote allergic reactions in susceptible individuals.

Clinical Applications of Bee Venom Acupoint Injection

Bee venom is a complex natural mixture with various pharmaceutical properties. Among these properties, its peptides and enzymes have potential medical therapy for pain relief and inflammation. In clinical settings, this therapy has been used widely to treat diseases by injecting into acupoints. In this article, we have conducted various research from PubMed, Cochrane Library, and Clinical Key from inception of July 2020. The results revealed that bee venom therapy has been reported effective in anti-inflammatory, antiapoptosis, and analgesic effects. Moreover, bee venom acupuncture has been commonly used for clinical disorders such as Parkinson disease, neuropathic pain, Alzheimer disease, intervertebral disc disease, spinal cord injury, musculoskeletal pain, arthritis, multiple sclerosis, skin disease and cancer.

Bee Venom Phospholipase A2 Ameliorates Atherosclerosis by Modulating Regulatory T Cells

Atherosclerosis is a chronic inflammatory disease caused by lipids and calcareous accumulations in the vascular wall due to an inflammatory reaction. Recent reports have demonstrated that regulatory T (Treg) cells have an important role as a new treatment for atherosclerosis. This study suggests that bee venom phospholipase A2 (bvPLA2) may be a potential therapeutic agent in atherosclerosis by inducing Treg cells. We examined the effects of bvPLA2 on atherosclerosis using ApoE^-/- and ApoE^-/-/Foxp3^DTR mice. In this study, bvPLA2 increased Treg cells, followed by a decrease in lipid accumulation in the aorta and aortic valve and the formation of foam cells. Importantly, the effect of bvPLA2 was found to depend on Treg cells. This study suggests that bvPLA2 can be a potential therapeutic agent for atherosclerosis.

Clinical Effectiveness and Adverse Events of Bee Venom Therapy: A Systematic Review of Randomized Controlled Trials

Bee venom has been used to treat many diseases because of its anti-inflammatory and analgesic effects. However, the secretions of bee venom can also cause life-threatening adverse reactions. The objective of this paper was to review the clinical effectiveness of bee venom and adverse events induced by bee venom, regardless of the disease. Four electronic databases were searched in April 2020. The reference lists of the retrieved articles and previous review articles were also hand-searched. Randomized controlled trials (RCTs) using any type of bee venom other than live bee stings for the clinical treatment of any disease other than cancer were included. The studies were selected, the data were extracted, and the quality of the studies was assessed by two authors. Risk of bias was assessed using the Cochrane risk of bias standards. Twelve RCTs were included in this review—three on Parkinson’s disease, four on arthralgia, four on musculoskeletal disorders, and one on polycystic ovary syndrome. The types of bee venom used were acupuncture injections, ultrasound gel, and an ointment. Six studies reported adverse events, and skin reactions such as pruritus and swelling were the most common. The large-scale clinical trials of bee venom therapy are needed to verify the statistical difference, and the reporting system for adverse events is also required to increase the safety of bee venom therapy.

Label-Free, Real-Time Phospholipase-A Isoform Assay

Phospholipase-A (PLA) enzymes catalyze the hydrolysis of ester bonds in select glycerophospholipids. Sensors for rapidly measuring the PLA activity in biological samples have relevance in the study of venom compositions and in medical diagnostics for the diagnosis of diseases such as acute pancreatitis. Current PLA sensor technologies are often restricted by the time it takes to prepare an assay, the necessity of using fluorescent labels, or the fact they might require strict pH control of the buffer vehicles used. Here we present a tethered bilayer lipid membrane (tBLM) impedance sensor array for the rapid and real-time detection of PLA, which includes the ability to selectively detect phospholipase-A₂ (PLA₂) from phospholipase-A₁ (PLA₁) isoforms. Comparing the activity of PLA₁ and PLA₂ in an array of tBLMs composed of ether phospholipids, ester phospholipids or ether-ester phospholipids allows for the rapid and reliable distinction between the isoforms, as measured using swept-frequency electrical impedance spectroscopy. After testing the assay using pure enzymes, we demonstrate the capacity of the sensor to identify specific PLA₂-type, calcium-dependent activity from the venom of the South American bullet ant, Paraponera clavata, at a concentration of 1 μg/mL. The specificity of the phospholipase activity was corroborated using matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. As further validation, we tested the activities of a PLA₁ isoform in the presence of different buffers commonly used in biology and biochemistry experiments. Sensitivity testing shows that PLA₁ can be detected at an activity as low as 0.06 U/mL. The rapid and reliable detection of phospholipases presented in this study has potential applications in the study of animal venoms as well as in lipase bioreactors and point-of-care devices.

Secreted Phospholipase A2 Group X Acts as an Adjuvant for Type 2 Inflammation, Leading to an Allergen-Specific Immune Response in the Lung

Secreted phospholipase A₂ (sPLA₂) enzymes release free fatty acids, including arachidonic acid, and generate lysophospholipids from phospholipids, including membrane phospholipids from cells and bacteria and surfactant phospholipids. We have shown that an endogenous enzyme sPLA₂ group X (sPLA₂-X) is elevated in the airways of asthmatics and that mice lacking the sPLA₂-X gene (Pla2g10) display attenuated airway hyperresponsiveness, innate and adaptive immune responses, and type 2 cytokine production in a model of airway sensitization and challenge using a complete allergen that induces endogenous adjuvant activity. This complete allergen also induces the expression of sPLA₂-X/Pla2g10 In the periphery, an sPLA₂ found in bee venom (bee venom PLA₂) administered with the incomplete Ag OVA leads to an Ag-specific immune response. In this study, we demonstrate that both bee venom PLA₂ and murine sPLA₂-X have adjuvant activity, leading to a type 2 immune response in the lung with features of airway hyperresponsiveness and Ag-specific type 2 airway inflammation following peripheral sensitization and subsequent airway challenge with OVA. Further, the adjuvant effects of sPLA₂-X that result in the type 2-biased OVA-specific adaptive immune response in the lung were dependent upon the catalytic activity of the enzyme, as a catalytically inactive mutant form of sPLA₂-X does not elicit the adaptive component of the immune response, although other components of the immune response were induced by the inactive enzyme, suggesting receptor-mediated effects. Our results demonstrate that exogenous and endogenous sPLA₂s play an important role in peripheral sensitization, resulting in airway responses to inhaled Ags.

Extending Metabolomic Studies of Apis mellifera Venom: LC-MS-Based Targeted Analysis of Organic Acids

Organic acids are important active small molecules present in venoms and toxins, which have not been fully explored yet. The aim of the study was the determination of organic acids in honeybee venom (HBV) samples by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two protocols for sample preparation were employed. A solid-phase extraction was used for the determination of malonic acid, fumaric acid, glutaric acid, and kynurenic acid. A dilute-and-shoot method was optimal for: citric acid, malic acid, and succinic acid. Chromatographic separation was performed using a Synergi Hydro-RP column. Detection was performed on a triple-quadrupole mass spectrometer operating in multiple reaction monitoring mode. Among the analytes, glutaric acid and kynurenic acid were present in HBV samples in the lowest concentrations, whereas citric acid was the most abundant acid in each sample, and accounted for an average of 86 mg/g (8.6%) of the venom dry weight. Organic acids were discussed in terms of function. This is the first study in the available literature that provides specific data on the content of organic acids in HBV using a validated quantitative method.

Alteration of Bumblebee Venom Composition toward Higher Elevation

Venomous animals use venom, a complex biofluid composed of unique mixtures of proteins and peptides, for either predation or defense. Bumblebees, which occur in various habitats due to their unique thermoregulatory properties, mainly use venom for defense. Herein, we conducted an exploratory analysis of the venom composition of a bumblebee species (Bombus pascuorum) along an elevation gradient in the western Swiss Alps using shot-gun proteomic approaches to assess whether their defense mechanism varies along the gradient. The gradient was characterized by high temperatures and low humidity at low elevations and low temperatures and high humidity at high elevations. Venom composition is changing along the elevation gradient, with proteomic variation in the abundances of pain-inducing and allergenic proteins. In particular, the abundance of phospholipase A₂-like, the main component of bumblebee venom, gradually decreases toward higher elevation (lower temperature), suggesting venom alteration and thus a decrease in bumblebee defense towards harsher environments. Larger datasets may complement this study to validate the observed novel trends.

Animal venoms: therapeutic tools for tackling Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative pathology of the central nervous system, mainly involving the selective and progressive loss of dopaminergic neurons from the substantia nigra, resulting in motor and non-motor symptoms. PD remains an incurable ailment; thus, treatments are limited to symptom alleviation. With long-term use, conventional treatments can become inefficient, often triggering possible side effects. Considering these drawbacks, drug discovery constantly turns to nature as a source of efficient therapeutics. Thus, this review explores animal venoms as a rich source of bioactive compounds with potent neuropharmacological profiles for the development of effective adjuvant treatments with fewer side effects, ultimately aiming for the neuroprotection of dopaminergic neurons and the symptomatic relief of PD.

Suppressive Effects of Bee Venom-Derived Phospholipase A2 on Mechanical Allodynia in a Rat Model of Neuropathic Pain

Bee venom (BV) has a long history of being used in traditional Korean medicine to relieve pain. Here, we investigated the effect of BV-derived phospholipase A2 (bvPLA2), a major component of BV, on peripheral nerve injury-induced neuropathic pain in rats. Spinal nerve ligation (SNL) was performed in Sprague Dawley rats to induce neuropathic pain, and paw withdrawal thresholds were measured using von Frey test. Mechanical allodynia, the representative symptom of neuropathic pain, was manifested following SNL and persisted for several weeks. The repetitive bvPLA2 treatment (0.2 mg/kg/day, i.p.) for two days significantly relieved the SNL-induced mechanical allodynia. The antiallodynic effect of bvPLA2 was blocked by spinal pretreatment with α1-adrenergic antagonist prazosin (30 μg, i.t.) but not with α2-adrenergic antagonist idazoxan (50 μg, i.t.). Also, the spinal application of α1-adrenergic agonist phenylephrine (50 μg, i.t.) reduced mechanical allodynia. These results indicate that bvPLA2 could relieve nerve injury-induced neuropathic mechanical allodynia through the activation of spinal α1-adrenergic receptors.

First Characterization of The Venom from Apis mellifera syriaca, A Honeybee from The Middle East Region

Bee venom is a mixture of several components with proven therapeutic benefits, among which are anti-inflammatory, analgesic, and various cardiovascular conditions. In this work, we analyzed for the first time the proteomic content and biological properties of the crude venom from Apis mellifera syriaca, a honeybee from the Middle East region. Using high-performance liquid chromatography-tandem mass spectrometry, we evidence the venom contains phospholipase A2, hyaluronidase, mast cell-degranulating peptide, adolapin, apamin, and melittin. The latter was purified by solid phase extraction method (SPE) and tested in parallel with crude venom for biological activities. Precisely, crude venom-but not melittin-exhibited antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains. Alongside, hemolytic activity was observed in human blood subjected to the venom at high doses. A. mellifera syriaca venom displayed antioxidant activities, and not surprisingly, PLA2 catalytic activity. Eventually, the venom proved to exert antiproliferative effects against MCF-7 and 3T3 cancer cells lines. This first report of a new bee venom opens new avenues for therapeutic uses of bee venoms.

Insect venom phospholipases A1 and A2: Roles in the envenoming process and allergy

Insect venom phospholipases have been identified in nearly all clinically relevant social Hymenoptera, including bees, wasps and ants. Among other biological roles, during the envenoming process these enzymes cause the disruption of cellular membranes and induce hypersensitive reactions, including life threatening anaphylaxis. While phospholipase A2 (PLA2) is a predominant component of bee venoms, phospholipase A1 (PLA1) is highly abundant in wasps and ants. The pronounced prevalence of IgE-mediated reactivity to these allergens in sensitized patients emphasizes their important role as major elicitors of Hymenoptera venom allergy (HVA). PLA1 and -A2 represent valuable marker allergens for differentiation of genuine sensitizations to bee and/or wasp venoms from cross-reactivity. Moreover, in massive attacks, insect venom phospholipases often cause several pathologies that can lead to fatalities. This review summarizes the available data related to structure, model of enzymatic activity and pathophysiological roles during envenoming process of insect venom phospholipases A1 and -A2.

Therapeutic effects of bee venom and its major component, melittin, on atopic dermatitis in vivo and in vitro

BACKGROUND AND PURPOSE

Atopic dermatitis (AD) is a multifactorial skin condition with complex interactions of innate and adaptive immune responses. There are several existing therapies for AD, including topical glucocorticosteroids, emollients, phototherapies, calcineurin inhibitors and immunosuppressants, such as cyclosporine A. Although these therapies reduce inflammation, they also cause serious side effects. Therefore, it is necessary to develop new therapeutic approaches for AD treatment without side effects. There are several studies on natural materials or toxins, such as herbs, ginseng extract and snake venom, for AD treatment. However, treatment of AD with bee venom and its major component, melittin has rarely been studied.

EXPERIMENTAL APPROACH

Effects of bee venom and melittin were studied in a model of AD in vivo induced by 1-chloro-2,4-dinitrobenzene (DNCB) in female Balb/c mice and in cultures of human keratinocytes, stimulated by TNF-α/IFN-γ. The potential pharmacological effects of bee venom and melittin on these in vivo and in vitro AD-like skin disease models were studied.

KEY RESULTS

Bee venom and melittin exhibited potent anti-atopic activities, shown by decreased AD-like skin lesions, induced by DNCB in mice. In vitro studies using TNF-α/IFN-γ-stimulated human keratinocytes showed that bee venom and melittin inhibited the increased expression of chemokines, such as CCL17 and CCL22, and pro-inflammatory cytokines, including IL-1β, IL-6 and IFN-γ, through the blockade of the NF-κB and STAT signalling pathways.

CONCLUSIONS AND IMPLICATIONS

Our results suggest that bee venom and melittin would be suitable for epicutaneous application, as topical administration is often appropriate for the treatment of AD.

Neuronal Cell Death and Mouse (Mus musculus) Behaviour Induced by Bee Venom

Neuronal cell death can occur in a tissue or organ, including the brain, which affects memory. The objectives of this study were to determine the dose of bee venom that causes neuronal death and analyse the alteration of mouse behaviour, focusing in particular on spatial memory. Fifteen male mice of Deutsche Denken Yoken (DDY) strain were divided into control and treatment groups. Bee venom was injected six times for two weeks intraperitoneally with 1.88 mg/kg, 3.76 mg/kg, 5.6 mg/kg, and 7.48 mg/kg doses of venom. Brain histology was studied using haematoxylin-eosin stained paraffin embedded 5 μm coronal sections. A Y maze test was used to assay behaviour. Parameters observed were the number of dead neurons and the percentage of mice with altered behaviour. ANOVA showed that the effects of bee venom were significantly different in the case of the neuronal death parameter but were not significantly different in the case of the mice behaviour parameter. Duncan’s Multiple Range Test (DMRT) demonstrated that P4 (7.48 mg/kg) gave the highest effect of bee venom to promote neuronal death.

Animal Toxins as Therapeutic Tools to Treat Neurodegenerative Diseases

Neurodegenerative diseases affect millions of individuals worldwide. So far, no disease-modifying drug is available to treat patients, making the search for effective drugs an urgent need. Neurodegeneration is triggered by the activation of several cellular processes, including oxidative stress, mitochondrial impairment, neuroinflammation, aging, aggregate formation, glutamatergic excitotoxicity, and apoptosis. Therefore, many research groups aim to identify drugs that may inhibit one or more of these events leading to neuronal cell death. Venoms are fruitful natural sources of new molecules, which have been relentlessly enhanced by evolution through natural selection. Several studies indicate that venom components can exhibit selectivity and affinity for a wide variety of targets in mammalian systems. For instance, an expressive number of natural peptides identified in venoms from animals, such as snakes, scorpions, bees, and spiders, were shown to lessen inflammation, regulate glutamate release, modify neurotransmitter levels, block ion channel activation, decrease the number of protein aggregates, and increase the levels of neuroprotective factors. Thus, these venom components hold potential as therapeutic tools to slow or even halt neurodegeneration. However, there are many technological issues to overcome, as venom peptides are hard to obtain and characterize and the amount obtained from natural sources is insufficient to perform all the necessary experiments and tests. Fortunately, technological improvements regarding heterologous protein expression, as well as peptide chemical synthesis will help to provide enough quantities and allow chemical and pharmacological enhancements of these natural occurring compounds. Thus, the main focus of this review is to highlight the most promising studies evaluating animal toxins as therapeutic tools to treat a wide variety of neurodegenerative conditions, including Alzheimer’s disease, Parkinson’s disease, brain ischemia, glaucoma, amyotrophic lateral sclerosis, and multiple sclerosis.

Isolation of biologically active peptides from the venom of Japanese carpenter bee, Xylocopa appendiculata

Background

Mass spectrometry-guided venom peptide profiling is a powerful tool to explore novel substances from venomous animals in a highly sensitive manner. In this study, this peptide profiling approach is successfully applied to explore the venom peptides of a Japanese solitary carpenter bee, Xylocopa appendiculata (Hymenoptera: Apoidea: Apidae: Anthophila: Xylocopinae: Xylocopini). Although interesting biological effects of the crude venom of carpenter bees have been reported, the structure and biological function of the venom peptides have not been elucidated yet.

Methods

The venom peptide profiling of the crude venom of X. appendiculata was performed by matrix-assisted laser desorption/ionization-time of flight mass spectroscopy. The venom was purified by a reverse-phase HPLC. The purified peptides were subjected to the Edman degradation, MS/MS analysis, and/or molecular cloning methods for peptide sequencing. Biological and functional characterization was performed by circular dichroism analysis, liposome leakage assay, and antimicrobial, histamine releasing and hemolytic activity tests.

Results

Three novel peptides with m/z 16508, 1939.3, and 1900.3 were isolated from the venom of X. appendiculata. The peptide with m/z 16508 was characterized as a secretory phospholipase A₂ (PLA₂) homolog in which the characteristic cysteine residues as well as the active site residues found in bee PLA₂s are highly conserved. Two novel peptides with m/z 1939.3 and m/z 1900.3 were named as Xac-1 and Xac-2, respectively. These peptides are found to be amphiphilic and displayed antimicrobial and hemolytic activities. The potency was almost the same as that of mastoparan isolated from the wasp venom.

Conclusion

We found three novel biologically active peptides in the venom of X. appendiculata and analyzed their molecular functions, and compared their sequential homology to discuss their molecular diversity. Highly sensitive mass analysis plays an important role in this study.

Electronic supplementary material

The online version of this article (doi:10.1186/s40409-017-0119-6) contains supplementary material, which is available to authorized users.

Metabolomic Profiling of the Synergistic Effects of Melittin in Combination with Cisplatin on Ovarian Cancer Cells

Melittin, the main peptide present in bee venom, has been proposed as having potential for anticancer therapy; the addition of melittin to cisplatin, a first line treatment for ovarian cancer, may increase the therapeutic response in cancer treatment via synergy, resulting in improved tolerability, reduced relapse, and decreased drug resistance. Thus, this study was designed to compare the metabolomic effects of melittin in combination with cisplatin in cisplatin-sensitive (A2780) and resistant (A2780CR) ovarian cancer cells. Liquid chromatography (LC) coupled with mass spectrometry (MS) was applied to identify metabolic changes in A2780 (combination treatment 5 μg/mL melittin + 2 μg/mL cisplatin) and A2780CR (combination treatment 2 μg/mL melittin + 10 μg/mL cisplatin) cells. Principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) multivariate data analysis models were produced using SIMCA-P software. All models displayed good separation between experimental groups and high-quality goodness of fit (R²) and goodness of prediction (Q²), respectively. The combination treatment induced significant changes in both cell lines involving reduction in the levels of metabolites in the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, purine and pyrimidine metabolism, and the arginine/proline pathway. The combination of melittin with cisplatin that targets these pathways had a synergistic effect. The melittin-cisplatin combination had a stronger effect on the A2780 cell line in comparison with the A2780CR cell line. The metabolic effects of melittin and cisplatin in combination were very different from those of each agent alone.

The Molecular Basis of Toxins' Interactions with Intracellular Signaling via Discrete Portals

An understanding of the molecular mechanisms by which microbial, plant or animal-secreted toxins exert their action provides the most important element for assessment of human health risks and opens new insights into therapies addressing a plethora of pathologies, ranging from neurological disorders to cancer, using toxinomimetic agents. Recently, molecular and cellular biology dissecting tools have provided a wealth of information on the action of these diverse toxins, yet, an integrated framework to explain their selective toxicity is still lacking. In this review, specific examples of different toxins are emphasized to illustrate the fundamental mechanisms of toxicity at different biochemical, molecular and cellular- levels with particular consideration for the nervous system. The target of primary action has been highlighted and operationally classified into 13 sub-categories. Selected examples of toxins were assigned to each target category, denominated as portal, and the modulation of the different portal’s signaling was featured. The first portal encompasses the plasma membrane lipid domains, which give rise to pores when challenged for example with pardaxin, a fish toxin, or is subject to degradation when enzymes of lipid metabolism such as phospholipases A₂ (PLA₂) or phospholipase C (PLC) act upon it. Several major portals consist of ion channels, pumps, transporters and ligand gated ionotropic receptors which many toxins act on, disturbing the intracellular ion homeostasis. Another group of portals consists of G-protein-coupled and tyrosine kinase receptors that, upon interaction with discrete toxins, alter second messengers towards pathological levels. Lastly, subcellular organelles such as mitochondria, nucleus, protein- and RNA-synthesis machineries, cytoskeletal networks and exocytic vesicles are also portals targeted and deregulated by other diverse group of toxins. A fundamental concept can be drawn from these seemingly different toxins with respect to the site of action and the secondary messengers and signaling cascades they trigger in the host. While the interaction with the initial portal is largely determined by the chemical nature of the toxin, once inside the cell, several ubiquitous second messengers and protein kinases/ phosphatases pathways are impaired, to attain toxicity. Therefore, toxins represent one of the most promising natural molecules for developing novel therapeutics that selectively target the major cellular portals involved in human physiology and diseases.

Comparative venomics of Psyttalia lounsburyi and P. concolor, two olive fruit fly parasitoids: a hypothetical role for a GH1 β-glucosidase

Venom composition of parasitoid wasps attracts increasing interest - notably molecules ensuring parasitism success on arthropod pests - but its variation within and among taxa is not yet understood. We have identified here the main venom proteins of two braconid wasps, Psyttalia lounsburyi (two strains from South Africa and Kenya) and P. concolor, olive fruit fly parasitoids that differ in host range. Among the shared abundant proteins, we found a GH1 β-glucosidase and a family of leucine-rich repeat (LRR) proteins. Olive is extremely rich in glycoside compounds that are hydrolyzed by β-glucosidases into defensive toxic products in response to phytophagous insect attacks. Assuming that Psyttalia host larvae sequester ingested glycosides, the injected venom GH1 β-glucosidase could induce the release of toxic compounds, thus participating in parasitism success by weakening the host. Venom LRR proteins are similar to truncated Toll-like receptors and may possibly scavenge the host immunity. The abundance of one of these LRR proteins in the venom of only one of the two P. lounsburyi strains evidences intraspecific variation in venom composition. Altogether, venom intra- and inter-specific variation in Psyttalia spp. were much lower than previously reported in the Leptopilina genus (Figitidae), suggesting it might depend upon the parasitoid taxa.

Protective Effects of Intratracheally-Administered Bee Venom Phospholipase A2 on Ovalbumin-Induced Allergic Asthma in Mice

Asthma is a common chronic disease characterized by bronchial inflammation, reversible airway obstruction, and airway hyperresponsiveness (AHR). Current therapeutic options for the management of asthma include inhaled corticosteroids and β2 agonists, which elicit harmful side effects. In the present study, we examined the capacity of phospholipase A2 (PLA2), one of the major components of bee venom (BV), to reduce airway inflammation and improve lung function in an experimental model of asthma. Allergic asthma was induced in female BALB/c mice by intraperitoneal administration of ovalbumin (OVA) on days 0 and 14, followed by intratracheal challenge with 1% OVA six times between days 22 and 30. The infiltration of immune cells, such as Th2 cytokines in the lungs, and the lung histology, were assessed in the OVA-challenged mice in the presence and absence of an intratracheal administration of bvPLA2. We showed that the intratracheal administration of bvPLA2 markedly suppressed the OVA-induced allergic airway inflammation by reducing AHR, overall area of inflammation, and goblet cell hyperplasia. Furthermore, the suppression was associated with a significant decrease in the production of Th2 cytokines, such as IL-4, IL-5, and IL-13, and a reduction in the number of total cells, including eosinophils, macrophages, and neutrophils in the airway.

Bee Venom for the Treatment of Parkinson Disease - A Randomized Controlled Clinical Trial

In the present study, we examined the potential symptomatic and/or disease-modifying effects of monthly bee venom injections compared to placebo in moderatly affected Parkinson disease patients. We conducted a prospective, randomized double-blind study in 40 Parkinson disease patients at Hoehn & Yahr stages 1.5 to 3 who were either assigned to monthly bee venom injections or equivalent volumes of saline (treatment/placebo group: n = 20/20). The primary objective of this study was to assess a potential symptomatic effect of s.c. bee venom injections (100 μg) compared to placebo 11 months after initiation of therapy on United Parkinson’s Disease Rating Scale (UPDRS) III scores in the « off » condition pre-and post-injection at a 60 minute interval. Secondary objectives included the evolution of UPDRS III scores over the study period and [123I]-FP-CIT scans to evaluate disease progression. Finally, safety was assessed by monitoring specific IgE against bee venom and skin tests when necessary. After an 11 month period of monthly administration, bee venom did not significantly decrease UPDRS III scores in the « off » condition. Also, UPDRS III scores over the study course, and nuclear imaging, did not differ significantly between treatment groups. Four patients were excluded during the trial due to positive skin tests but no systemic allergic reaction was recorded. After an initial increase, specific IgE against bee venom decreased in all patients completing the trial. This study did not evidence any clear symptomatic or disease-modifying effects of monthly bee venom injections over an 11 month period compared to placebo using a standard bee venom allergy desensitization protocol in Parkinson disease patients. However, bee venom administration appeared safe in non-allergic subjects. Thus, we suggest that higher administration frequency and possibly higher individual doses of bee venom may reveal its potency in treating Parkinson disease.

Anti-Inflammatory Applications of Melittin, a Major Component of Bee Venom: Detailed Mechanism of Action and Adverse Effects

Inflammation is a pervasive phenomenon triggered by the innate and adaptive immune systems to maintain homeostasis. The phenomenon normally leads to recovery from infection and healing, but when not properly phased, inflammation may cause immune disorders. Bee venom is a toxin that bees use for their protection from enemies. However, for centuries it has been used in the Orient as an anti-inflammatory medicine for the treatment of chronic inflammatory diseases. Bee venom and its major component, melittin, are potential means of reducing excessive immune responses and provide new alternatives for the control of inflammatory diseases. Recent experimental studies show that the biological functions of melittin could be applied for therapeutic use in vitro and in vivo. Reports verifying the therapeutic effects of melittin are accumulating in the literature, but the cellular mechanism(s) of the anti-inflammatory effects of melittin are not fully elucidated. In the present study, we review the current knowledge on the therapeutic effects of melittin and its detailed mechanisms of action against several inflammatory diseases including skin inflammation, neuroinflammation, atherosclerosis, arthritis and liver inflammation, its adverse effects as well as future prospects regarding the use of melittin.

Regulatory T Cells Contribute to the Inhibition of Radiation-Induced Acute Lung Inflammation via Bee Venom Phospholipase A₂ in Mice

Bee venom has long been used to treat various inflammatory diseases, such as rheumatoid arthritis and multiple sclerosis. Previously, we reported that bee venom phospholipase A₂ (bvPLA₂) has an anti-inflammatory effect through the induction of regulatory T cells. Radiotherapy is a common anti-cancer method, but often causes adverse effects, such as inflammation. This study was conducted to evaluate the protective effects of bvPLA₂ in radiation-induced acute lung inflammation. Mice were focally irradiated with 75 Gy of X-rays in the lung and administered bvPLA₂ six times after radiation. To evaluate the level of inflammation, the number of immune cells, mRNA level of inflammatory cytokine, and histological changes in the lung were measured. BvPLA₂ treatment reduced the accumulation of immune cells, such as macrophages, neutrophils, lymphocytes, and eosinophils. In addition, bvPLA₂ treatment decreased inflammasome-, chemokine-, cytokine- and fibrosis-related genes' mRNA expression. The histological results also demonstrated the attenuating effect of bvPLA₂ on radiation-induced lung inflammation. Furthermore, regulatory T cell depletion abolished the therapeutic effects of bvPLA₂ in radiation-induced pneumonitis, implicating the anti-inflammatory effects of bvPLA₂ are dependent upon regulatory T cells. These results support the therapeutic potential of bvPLA₂ in radiation pneumonitis and fibrosis treatments.