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.

[Serum concentration of phospholipase A2 and platelet aggregation during hyperbaric oxygen therapy in patients with ischemic heart disease]. / Syvorotochnaya kontsentratsiya fosfolipazy A2 i agregatsiya trombotsitov pri giperbaricheskoi oksigenoterapii u patsientov s ishemicheskoi bolezn'yu serdtsa.

Hyperbaric oxygenation (HBO) for correction of platelet haemostasis disorders in coronary heart disease (CHD) is reasonable due to the associated hypocoagulation. However, in practice, the baseline state of platelet activity is not considered when prescribing HBO therapy. Available publications lack information on structural changes in the platelet membrane associated with the of phospholipase A2 (PLA2) activity, and on the HBO effect on the various steps of hemostasis. OBJECTIVE: To study changes in serum PLA2 concentration and its relation to platelet aggregation activity during HBO in patients with stable CHD. MATERIAL AND METHODS: We examined 42 patients with stable angina FC II-III, 27 received antiplatelet therapy (Cardiomagnyl 75 mg: acetylsalicylic acid + magnesium hydroxide), and 15 patients did not. All patients received a 10-day course of HBO at 1.2 atmosphere mode for 40 min. Platelet hemostasis and serum PLA2 concentration were evaluated. Platelet aggregation was tested using Biola LA-230-2 aggregation analyzer (Biola Scientific, Russia). The platelets count and mean platelet volume (MPV) were determined on a Mindray BS-3200 hematology analyzer (Mindray, China). PLA2 levels were determined by enzyme immunoassay using Model 680 microplate reader (Bio-Rad, USA). Residual platelet reactivity was evaluated by 5.0 ADP-induced aggregation. RESULTS: Assessment of the HBO effect on the functional state of platelets depending on their aggregation activity and the therapy taken showed a significant increase in spontaneous aggregation and ADP-induced aggregation at inducer concentration of 1.0 µM (p=0.049) in patients with baseline hyperaggregation taking Cardiomagnyl after HBO. No significant changes in PLA2 concentration were observed. At the same time, patients with baseline hyperaggregation who did not take antiplatelet agents had no changes in platelet aggregation activity and a decreased serum PLA2. In patients with baseline normal aggregation receiving an antiplatelet drug, a course of HBO had no effect on platelet aggregation activity and PLA2 level. In patients with baseline normal aggregation who did not take antiplatelet agents, a course of HBO resulted in significant decrease in PLA2 levels and no changes in platelet aggregation activity. In patients with low aggregation activity (hypoaggregation) who took antiplatelet agents, a significant increase in spontaneous aggregation and no change of serum PLA2 after an HBO course was observed. CONCLUSION: The study showed a divergent response to the hyperbaric oxygen, depending on the antiplatelet therapy and the background aggregation.

Bee Venom Components as Therapeutic Tools against Prostate Cancer.

Prostate cancer is one of the most common cancers in men. Despite the development of a variety of therapeutic agents to treat either metastatic hormone-sensitive prostate cancer, advanced prostate cancer, or nonmetastatic/metastatic castration-resistant prostate cancer, the progression or spread of the disease often cannot be avoided. Additionally, the development of resistance of prostate cancer cells to available therapeutic agents is a well-known problem. Despite extensive and cost-intensive research over decades, curative therapy for metastatic prostate cancer is still not available. Therefore, additional therapeutic agents are still needed. The animal kingdom offers a valuable source of natural substances used for the treatment of a variety of diseases. Bee venom of the honeybee is a mixture of many components. It contains proteins acting as enzymes such as phospholipase A2, smaller proteins and peptides such as melittin and apamin, phospholipids, and physiologically active amines such as histamine, dopamine, and noradrenaline. Melittin has been shown to induce apoptosis in different cancer cell lines, including prostate cancer cell lines. It also influences cell proliferation, angiogenesis, and necrosis as well as motility, migration, metastasis, and invasion of tumour cells. Hence, it represents an interesting anticancer agent. In this review article, studies about the effect of bee venom components on prostate cancer cells are discussed. An electronic literature research was performed utilising PubMed in February 2021. All scientific publications, which examine this interesting subject, are discussed. Furthermore, the different types of application of these promising substances are outlined. The studies clearly indicate that bee venom or melittin exhibited anticancer effects in various prostate cancer cell lines and in xenografts. In most of the studies, a combination of bee venom or the modified melittin with another molecule was utilised in order to avoid side effects and, additionally, to target selectively the prostate cancer cells or the surrounding tissue. The studies showed that systemic side effects and unwanted damage to healthy tissue and organs could be minimised when the anticancer drug was not activated until binding to the cancer cells or the surrounding tissue. Different targets were used, such as the matrix metalloproteinase 2, hormone receptors expressed by prostate cancer cells, the extracellular domain of PSMA, and the fibroblast activation protein occurring in the stroma of prostate cancer cells. Another approach used loaded phosphate micelles, which were cleaved by the enzyme secretory phospholipase A2 produced by prostate cancer cells. In a totally different approach, targeted nanoparticles containing the melittin gene were used for prostate cancer gene therapy. By the targeted nonviral gene delivery, the gene encoding melittin was delivered to the prostate cancer cells without systemic side effects. This review of the scientific literature reveals totally different approaches using bee venom, melittin, modified melittin, or protoxin as anticancer agents. The toxic agents acted through several different mechanisms to produce their anti-prostate cancer effects. These mechanisms are not fully understood yet and more experimental studies are necessary to reveal the complete mode of action. Nevertheless, the researchers have conducted pioneering work. Based on these results, further experimental and clinical studies about melittin and modifications of this interesting agent deriving from nature are necessary and could possibly lead to a complementary treatment option for prostate cancer.

Bee Venom and Its Sub-Components: Characterization, Pharmacology, and Therapeutics.

Bee venom, which is a complex substance produced by Apis mellifera, is widely used to treat various diseases, such as pain [...].

Prophylactic Effects of Bee Venom Phospholipase A2 in Lipopolysaccharide-Induced Pregnancy Loss.

Spontaneous abortion represents a common form of embryonic loss caused by early pregnancy failure. In the present study, we investigated the prophylactic effects of bee venom phospholipase A2 (bvPLA2), a regulatory T cell (Treg) inducer, on a lipopolysaccharide (LPS)-induced abortion mouse model. Fetal loss, including viable implants, the fetal resorption rate, and the fetal weight, were measured after LPS and bvPLA2 treatment. The levels of serum and tissue inflammatory cytokines were determined. To investigate the involvement of the Treg population in bvPLA2-mediated protection against fetal loss, the effect of Treg depletion was evaluated following bvPLA2 and LPS treatment. The results clearly revealed that bvPLA2 can prevent fetal loss accompanied by growth restriction in the remaining viable fetus. When the LPS-induced abortion mice were treated with bvPLA2, Treg cells were significantly increased compared with those in the non-pregnant, PBS, and LPS groups. After LPS injection, the levels of proinflammatory cytokines were markedly increased compared with those in the PBS mouse group, while bvPLA2 treatment showed significantly decreased TNF-α and IFN-γ expression compared with that in the LPS group. The protective effects of bvPLA2 treatment were not detected in Treg-depleted abortion-prone mice. These findings suggest that bvPLA2 has protective effects in the LPS-induced abortion mouse model by regulating Treg populations.

Bee venom phospholipase A2 ameliorates Alzheimer's disease pathology in Aß vaccination treatment without inducing neuro-inflammation in a 3xTg-AD mouse model.

Alzheimer's disease (AD) is the most common form of dementia and is characterized by an imbalance between the production and clearance of amyloid-beta (Aß) and tau proteins. Although vaccination against Aß peptide results in a dramatic reduction in Aß pathology in experimental mouse models, the initial clinical trial for an active Aß vaccine was halted early due to the development of acute meningoencephalitis in 6% of the immunized patients, which likely involved a T-cell mediated pro-inflammatory response. In this study, we aimed to determine whether bee venom phospholipase A2 (bvPLA2) treatment would induce Tregs and ameliorate AD pathology without unwanted T cell-mediated inflammation. First, we investigated the effects of bvPLA2 on the inflammatory infiltration caused by Aß vaccination. Inflammatory aggregates of CD3+ T lymphocytes and macrophages were found in the brains and spinal cords of mice treated with Aß. However, administration of bvPLA2 dramatically eliminated central nervous system inflammation following Aß immunization. In AD model mice (3xTg-AD mice), bvPLA2 administration significantly ameliorated cognitive deficits and reduced Aß burdens in the brains of Aß-vaccinated 3xTg-AD mice. Additionally, we examined brain glucose metabolism using positron emission tomography with 18F-2 fluoro-2-deoxy-D-glucose. Cerebral glucose uptake was considerably higher in the brains of Aß-vaccinated 3xTg-AD mice that received bvPLA2 than those that did not. The present study suggests that the modulation of Treg populations via bvPLA2 treatment may be a new therapeutic approach to attenuate the progression of AD in conjunction with Aß vaccination therapy without an adverse inflammatory response.

Native and recombinant phospholipases A2 of Scorpio maurus venom glands impair angiogenesis by targeting integrins α5ß1 and αvß3.

We recently purified an heterodimeric phospholipase A2 named Sm-PLGV from the venom glands of scorpion Scorpio maurus containing a Long chain, a penta-peptide insertion, which is cut out during the maturation, followed by a short chain. Three recombinant forms of Sm-PLGV were produced in Escherichia coli: rPLA2(+5) containing the full-length sequence including the penta-peptide insert, rPLA2(-5) a fused continuous chain of the Long and the short chains without the penta-peptide and the Long chain alone without the short one. In this study, we showed that Sm-PLGV, rPLA2(+5) and rPLA2(-5) displayed more potent anti-angiogenic properties than the recombinant Long chain and the short chain obtained by chemical synthesis. These phospholipases A2 inhibited in a dose-dependent manner adhesion, migration and invasion of human microvascular endothelial cells through the alteration of α5ß1 and αvß3 integrins function. Using Matrigel™ and chick chorioallantoic membrane assays, we demonstrated that Sm-PLGV, rPLA2(+5) and rPLA2(-5) significantly inhibited both in vitro and in vivo angiogenesis. We also showed a clear dissociation of the anti-angiogenic effect of Sm-PLGV and its catalytic activity. This is the first study describing an anti-angiogenic effect for recombinant scorpion venom enzymes.

Bee Venom Phospholipase A2 Alleviate House Dust Mite-Induced Atopic Dermatitis-Like Skin Lesions by the CD206 Mannose Receptor.

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by highly pruritic, erythematous, and eczematous skin plaques. We previously reported that phospholipase A2 (PLA2) derived from bee venom alleviates AD-like skin lesions induced by 2,4-dinitrochlorobenzene (DNCB) and house dust mite extract (Dermatophagoides farinae extract, DFE) in a murine model. However, the underlying mechanisms of PLA2 action in actopic dermatitis remain unclear. In this study, we showed that PLA2 treatment inhibited epidermal thickness, serum immunoglobulin E (IgE) and cytokine levels, macrophage and mast cell infiltration in the ear of an AD model induced by DFE and DNCB. In contrast, these effects were abrogated in CD206 mannose receptor-deficient mice exposed to DFE and DNCB in the ear. These data suggest that bvPLA2 alleviates atopic skin inflammation via interaction with CD206.

Photobiomodulation of local alterations induced by BthTX-I, a phospholipase A2 myotoxin from Bothrops jararacussu snake venom: In vivo and in vitro evaluation.

This report describes the effect of photobiomodulation (PBM) on edema formation, leukocyte influx, prostaglandin E2 (PGE2) biosynthesis and cytotoxicity caused by bothropstoxin-I (BthTX-I), a phospholipase A2 (PLA2) homologue isolated from Bothrops jararacussu snake venom. Swiss mice or C2C12 cells were irradiated with low-level laser (LLL) at 685nm wavelength, an energy density of 4.6J/cm2 and an irradiation time of 13s. To evaluate the effect on edema formation and leukocyte influx, LLL was applied to the site of inoculation 30min and 3h post-injection. C2C12 cells were exposed to BthTX-I and immediately irradiated. PBM significantly reduced paw edema formation, peritoneal leukocyte influx and PGE2 synthesis, but increased the viability of C2C12 muscle cells after BthTX-I incubation. These findings demonstrate that PBM attenuated the inflammatory events induced by BthTX-I. The attenuation of PGE2 synthesis could be an important factor in the reduced inflammatory response caused by laser irradiation. The ability of LLL irradiation to protect muscle cells against the deleterious effects of BthTX-I may indicate preservation of the plasma membrane.

Suppressive Effects of Bee Venom Acupuncture on Paclitaxel-Induced Neuropathic Pain in Rats: Mediation by Spinal α2-Adrenergic Receptor.

Paclitaxel, a chemotherapy drug for solid tumors, induces peripheral painful neuropathy. Bee venom acupuncture (BVA) has been reported to have potent analgesic effects, which are known to be mediated by activation of spinal α-adrenergic receptor. Here, we investigated the effect of BVA on mechanical hyperalgesia and spinal neuronal hyperexcitation induced by paclitaxel. The role of spinal α-adrenergic receptor subtypes in the analgesic effect of BVA was also observed. Administration of paclitaxel (total 8 mg/kg, intraperitoneal) on four alternate days (days 0, 2, 4, and 6) induced significant mechanical hyperalgesic signs, measured using a von Frey filament. BVA (1 mg/kg, ST36) relieved this mechanical hyperalgesia for at least two hours, and suppressed the hyperexcitation in spinal wide dynamic range neurons evoked by press or pinch stimulation. Both melittin (0.5 mg/kg, ST36) and phospholipase A2 (0.12 mg/kg, ST36) were shown to play an important part in this analgesic effect of the BVA, as they significantly attenuated the pain. Intrathecal pretreatment with the α2-adrenergic receptor antagonist (idazoxan, 50 µg), but not α1-adrenergic receptor antagonist (prazosin, 30 µg), blocked the analgesic effect of BVA. These results suggest that BVA has potent suppressive effects against paclitaxel-induced neuropathic pain, which were mediated by spinal α2-adrenergic receptor.

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 ß2 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.

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.

Preventive Effects of Bee Venom Derived Phospholipase A2 on Oxaliplatin-Induced Neuropathic Pain in Mice.

Oxaliplatin, a chemotherapy drug used to treat colorectal cancer, induces specific sensory neurotoxicity signs that are aggravated by cold and mechanical stimuli. Here we examined the preventive effects of Bee Venom (BV) derived phospholipase A2 (bvPLA2) on oxaliplatin-induced neuropathic pain in mice and its immunological mechanism. The cold and mechanical allodynia signs were evaluated by acetone and von Frey hair test on the hind paw, respectively. The most significant allodynia signs were observed at three days after an injection of oxaliplatin (6 mg/kg, i.p.) and then decreased gradually to a normal level on days 7-9. The oxaliplatin injection also induced infiltration of macrophages and upregulated levels of the pro-inflammatory cytokine interleukin (IL)-1ß in the lumbar dorsal root ganglia (DRG). Daily treatment with bvPLA2 (0.2 mg/kg, i.p.) for five consecutive days prior to the oxaliplatin injection markedly inhibited the development of cold and mechanical allodynia, and suppressed infiltration of macrophages and the increase of IL-1ß level in the DRG. Such preventive effects of bvPLA2 were completely blocked by depleting regulatory T cells (Tregs) with CD25 antibody pre-treatments. These results suggest that bvPLA2 may prevent oxaliplatin-induced neuropathic pain by suppressing immune responses in the DRG by Tregs.

Effects of human Parvovirus B19 and Bocavirus VP1 unique region on tight junction of human airway epithelial A549 cells.

As is widely recognized, human parvovirus B19 (B19) and human bocavirus (HBoV) are important human pathogens. Obviously, both VP1 unique region (VP1u) of B19 and HBoV exhibit the secreted phospholipase A2 (sPLA2)-like enzymatic activity and are recognized to participate in the pathogenesis of lower respiratory tract illnesses. However, exactly how, both VP1u from B19 and HBoV affect tight junction has seldom been addressed. Therefore, this study investigates how B19-VP1u and HBoV-VP1u may affect the tight junction of the airway epithelial A549 cells by examining phospholipase A2 activity and transepithelial electrical resistance (TEER) as well as performing immunoblotting analyses. Experimental results indicate that TEER is more significantly decreased in A549 cells by treatment with TNF-α (10 ng), two dosages of B19-VP1u and BoV-VP1u (400 ng and 4000 ng) or bee venom PLA2 (10 ng) than that of the control. Accordingly, more significantly increased claudin-1 and decreased occludin are detected in A549 cells by treatment with TNF-α or both dosages of HBoV-VP1u than that of the control. Additionally, more significantly decreased Na+/K+ ATPase is observed in A549 cells by treatment with TNF-α, high dosage of B19-VP1u or both dosages of BoV-VP1u than that of the control. Above findings suggest that HBoV-VP1u rather than B19 VP1u likely plays more important roles in the disruption of tight junction in the airway tract. Meanwhile, this discrepancy appears not to be associated with the secreted phospholipase A2 (sPLA2)-like enzymatic activity.

Changes in wetting properties of alumina surface treated with DPPC in the presence of phospholipase A2 enzyme.

Wetting properties of commercial Al(2)O(3) plates contacted with dipalmitoylphosphatidylcholine (DPPC) or DPPC+enzyme (phospholipase PLA(2)) in NaCl solution were determined by thin layer wicking and with the help of Washburn equation. Van Oss et al.'s approach to interfacial free energy interactions was applied to determining the solid surface free energy components. Wicking experiments were performed both for bare and alumina plates precontacted overnight with the probe liquid saturated vapours, as well as the untreated and DPPC (or DPPC+PLA(2)) treated alumina plates. For this purpose the penetration rates of n-octane, water and formamide were measured. From these experiments it resulted that original alumina surface is strongly polar with electron-donor interactions originating from the surface hydroxyl groups. Adsorption of DPPC on Al(2)O(3) plates slightly increased the hydrophobic character of the alumina surface (considerable decrease of the electron-donor, γ(s)(-) parameter and γ(s)(AB) component was visible) in such a way that the hydrocarbon chains were directed outwards and the polar part towards the alumina surface. However, after the enzyme action the products of DPPC hydrolysis by PLA(2) (palmitic acid and lysophosphatidylcholine) increased again the hydrophilic character of Al(2)O(3) surface (a minor increase in γ(s)(AB) component and drastic increase of the electron-donor γ(s)(-) parameter was noticeable). After treatment with DPPC or DPPC+enzyme PLA(2) solution the changes of the total surface free energy of alumina and its Lifshits-van der Waals (γ(s)(LW)) component were in the range 7-10 mJ/m(2), but the most considerable and delivering more interesting information were the changes of the electron-donor (γ(s)(-)) parameter ranging from 27 to 35 mJ/m(2). Moreover, the changes of the alumina surface wettability were dependent on the time of the enzyme contacting with DPPC in NaCl solution. On the basis of the obtained results it seems that the thin layer wicking method can be an additional useful tool in investigations of the effect of phospholipid and PLA(2) action on the hydrophilic-hydrophobic character of alumina surface.