**6. Biotechnological and pharmacological applications of bee and wasp toxins**

Stinging accidents caused by wasps and bees generally produce severe pain, local damage and even death in various vertebrates including man, caused by action of their venoms. Bee venom contains a variety of compounds peptides including melittin, apamin, adolapin, and mast cell degranulating (MCD) peptide, in addition of hyaluronidase and phospholipase A enzymes, that plays a variety of biological activities. The chemical constituents of venoms from wasps species include acetylcholine, serotonin, norepinephrine, hyaluronidase, histi‐ dine decarboxylase, phospholipase A2 and several polycationic peptides and proteins [12].

### **6.1. Toxins acting on cardiovascular system**

**5.4. Toxins acting on inflammatory and nociceptive responses**

D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) and related heptapeptide [Hyp6

have been found to exhibit high selectivity for δ-opiate receptors [176].

**5.5. Toxins with anticancer and cytotoxic activities**

pronounced cytotoxicity towards malignant cells [181].

**5.6. Toxins with insulin releasing activity**

**toxins**

Applications

36

Epibatidine, an azabicycloheptane alkaloid isolated from the skin of frog *Epipedobates tricol‐ or*, was found to be a potent antinociceptive compound. Although its toxicity, this toxin could be a lead compound in the development of therapeutic agents for pain relief as well for treatment of disorders whose pathogenesis involves nicotinic receptors [175]. A variety of toxins acting on opioid receptors have been isolated from amphibians. Dermorphin (Tyr-

An Integrated View of the Molecular Recognition and Toxinology - From Analytical Procedures to Biomedical

from the frog skin of *Phyllomedusa* sp., show higher affinity for μ-opioid receptors. Several peptides belonging to the dermorphin family have been isolated from frog skin [61]. Deltor‐ phins (also referred as dermenkephalin) and related peptides isolated from the frog skin

*Venenum Bufonis* is a traditional Chinese medicine obtained from the dried white secretion of auricular and skin glands of Chinese toads (*Bufo melanostictus* Schneider or *Bufo bufo gargar‐ zinas* Cantor). Cinobufagin (CBG), isolated from *Venenum Bufonis*, had potential immune system regulatory effects and is suggested that this compound could be developed as a nov‐ el immunotherapeutic agent to treat immune-mediated diseases such as cancer [177]. Bufa‐ dienolides from toxic glands of toads are used as anticancer agents, mainly on leukemia cells. Bufalin and cinobufagin from *Bufo bufo gargarizans* Cantor were tested and studies shown that these toxins suppress cell proliferation and cause apoptosis in prostate cancer cells via a sequence of apoptotic modulators [178]. Bufotalin, one of the bufadienolides iso‐ lated from Formosan Ch'an Su, which is made of the skin and parotid glands of toads, in‐ duce apoptosis in human hepatocellular carcinoma, probably involving caspases and apopotosis-inducing factor [179]. Cutaneous venom of *Bombina variegata pachypus* toad pre‐ sented a cytolitic effect on the growth of the human HL 60 cell line [180]. Brevinin-2R, a nonhemolytic defensin has been isolated from the skin of the frog *Rana ridibunda*, showing

Diabetes mellitus is a disease in which the body is unable to sufficiently produce or properly use insulin. Newer therapeutic modalities for this disease are extremely needed. Peptides with insulin-releasing activity have been isolated from the skin secretions of the frog *Aga‐ lychnis litodryas* and may serve as templates for a novel class of insulin secretagogues [182].

**6. Biotechnological and pharmacological applications of bee and wasp**

Stinging accidents caused by wasps and bees generally produce severe pain, local damage and even death in various vertebrates including man, caused by action of their venoms. Bee

]-dermorphin isolated

Honey bee venom and its main constituents have a marked effect on the cardiovascular system, most notably a fall in arterial blood pressure [183]. From the hemodynamic point of view, the venom, in higher doses, is extremely toxic to the circulatory system and in smaller doses, however, produce a stimulatory effect upon the heart [184]. Melittin, a strongly basic 26 aminoacid polypeptide which constitutes 40–60% of the whole dry honeybee venom, induces con‐ tractures and depolarization in skeletal muscle [12]. Melittin is cardiotoxic *in vitro*, causing arrest of the rat heart, but only induces a slight hypertension *in vivo* [183]. Apamin, without direct effect on contraction or relaxation, could attenuate the relaxation evoked by melittin at lower concentrations, and thus contribute to the conversion of melittin's relaxing activity into the contractile activity of the venom. Another peptide found in bee venom that outlines effects on the cardiovascular system is the Cardiopep. Cardiopep is a relatively nonlethal compo‐ nent, compared to phospholipase A, melittin, or whole bee venom itself. It is a potent nontox‐ ic beta-adrenergio-like stimulant that possesses definite anti-arrhythmic properties [185]. Studies on the cardiovascular effects of mastoparan B, isolated from the venom of the hor‐ net *Vespa basalis,* has shown that the peptide caused a dose-dependent inhibition of blood pressure and cardiac function in the rat. Research has shown that the cardiovascular effects of mastoparan B are mainly due to the actions of serotonin, and by a lesser extent to other autacoids, released from mast cells as well from other biocompartments [186].

### **6.2. Toxins acting on hemostasis**

The mechanism by which bee venom affects the hemostatic system remains poorly under‐ stood [187]. Among the serine proteases isolated from bees, which acts as a fibrin(ogen)olyt‐ ic enzyme, activator prothrombin and directly degrades fibrinogen into fibrin degradation products, are the Bi-VSP (*Bombus ignitus*) [188], Bt-VSP (*Bombus terrestris*) [189] and Bs-VSP (*Bombus hypocrita sapporoensis*) [190]. According reference [188], the activation of prothrom‐ bin and fibrin(ogen)olytic activity may cooperate to effectively remove fibrinogen, and thus reduce the viscosity of blood. The injection fibrin(ogen)olytic enzyme can be used to facili‐ tate the propagation of components of bee venom throughout the bloodstream of mammals. Bumblebee venom also affects the hemostatic system through by Bi-KTI (*B. ignitus*), a Ku‐ nitz-type inhibitor, that strongly inhibited plasmin during fibrinolysis, indicating that Bi-KTI specifically targets plasmin [187]. A toxin protein named magnvesin was purified of *Vespa magnifica*. This protein contains serine protease-like activity inhibits blood coagulation, and was found to act on factors TF, VII, VIII, IX and X [191]. Other anticoagulant protein (protease I) with proteolytic activity was purified from *Vespa orientalis* venom, involving mainly coagulation factors VIII and IX [192]. Magnifin, a phospholipase A1 (PLA1) purified

from wasp venoms of *V. magnifica*, is very similar to other (PLA1), especially to other wasp allergen PLA1. Magnifin can activate platelet aggregation and induce thrombosis *in vivo*. It was the first report of PLA1 from wasp venoms that can induce platelet aggregation [193].

system [203]. MCDP, isolated of *Apis mellifera* venom, is a strong mediator of mast cell de‐

Toxins from Venomous Animals: Gene Cloning, Protein Expression and Biotechnological Applications

http://dx.doi.org/10.5772/52380

39

Characterization of the primary structure of allergens is a prerequisite for the design of new diagnostic and therapeutic tools for allergic diseases. Major allergens in bee venom (recog‐ nized by IgE in more than 50% of patients) include phospholipase A2 (PLA2), acid phospha‐ tase, hyaluronidase and allergen C, as well as several proteins of high molecular weights (MWs) [205]. Besides these, Api m 6, was frequently (42%) recognized by IgE from bee ven‐ om hypersensitive patients [206]; from wasp venom were purified Vesp c 1 (phospholipase A1) and Vesp c 5 (antigen-5) from *Polistes gallicus*, and Vesp ma 2 and Vesp ma 5 from *Vespa magnifica*, [207-208]. Formulations of poly(lactic-co-glycolic acid) (PLGA) microspheres rep‐ resent a strategy for replacing immunotherapy in multiple injections of venom. The results obtained with bee venom proteins encapsulated showed that the allergens may still be effec‐ tive in the induction of an immune response and so may be a new formulation for VIT [209]. Recombinant proteins with immunosuppressive properties have been reported in the litera‐ ture, such as rVPr1 and rVRr3, identified, cloned and expressed from isolated VPR1 and VPr2 from *Pimpla hypochondriaca* [210]. Chemotactic peptide protonectin 1-6 (ILGTIL-NH2) was detected in the venom of the social wasp *Agelaia pallipes pallipes* [211]. Polybia-MPI and Polybia-CP were isolated from the venom of the social wasp *Polybia paulista* and character‐ ized as chemotactic peptides for PMNL cells [212]. Under the diagnosis, the microarray was reported. Protein chips can be spotted with thousands of proteins or peptides, permitting to analyses the IgE responses against a tremendous variety of allergens. First attempts to mi‐ croarray with Hymenoptera venom allergens included Api m 1, Api m 2, Ves v 5, Ves g 5 and Pol a 5 in a set-up with 96 recombinant or natural allergen molecules representative of most important allergen sources. The venom allergens from different bee, wasp and ant spe‐ cies can be offered on a single chip, allowing to differentiate the species that has stung based on species-specific markers. The allergen microarray allows the determination and monitor‐ ing of allergic patients' IgE reactivity profiles to large numbers of disease-causing allergens

granulation and releases histamine at low concentrations [204].

by using single measurements and minute amounts of serum [213].

Bee venom is the most studied among the arthropods covered in this chapter regarding its anti-cancer activities, due mainly to two substances that have been isolated and character‐ ized: melittin and phospholipase A2 (PLA2). Melittin and PLA2 are the two major compo‐ nents in the venom of the species *Apis mellifera* [214]. Melittin is inhibitor of calmodulin activity and is an inhibitor of cell growth and clonogenicity of human and murine leukemic cells [215]. Study indicated that key regulators in bee venom-induced apoptosis are Bcl-2 and caspase-3 in human leukemic U937 cells through down-regulation of the ERK and Akt signal pathway [216]. Furthermore recent reports indicate that BV is also able to inhibit tu‐ mor growth and exhibit anti-tumor activity *in vitro* and *in vivo* and can be used as a chemo‐ therapeutic agent against malignancy [217]. The adjuvant treatment with PLA2 and

**6.6. Toxins with anticancer and cytotoxic activities**

**6.5. Toxins acting on immunological system**

### **6.3. Toxins with antibiotic activity**

Antimicrobial peptides have attracted much attention as a novel class of antibiotics, espe‐ cially for antibiotic-resistant pathogens. They provide more opportunities for designing nov‐ el and effective antimicrobial agents [194]. Melittin has various biological, pharmacological and toxicological actions including antibacterial and antifungal activities [195]. Bombolitin (structural and biological properties similar to those of melittin), isolated from the venom of *B. ignitus* worker bees, possesses antimicrobial activity and show inhibitory effects on bacte‐ rial growth for Gram-positive, Gram-negative bacteria and fungi, suggesting that bomboli‐ tin is a potential antimicrobial agent [196]. Osmin, isolated of solitary bee *Osmia rufa*, shows some similarities with the mast cell degranulation (MCD) peptide family. Free acid and Cterminally amidated osmins were chemically synthesized and tested for antimicrobial and haemolytic activities. Antimicrobial and antifungal tests indicated that both peptides were able to inhibit bacterial and fungal growth [197]. Two families of bioactive peptides which belongs to mastoparans (12a and 12b) and chemotactic peptides (5e, 5g and 5f) were purified and characterized from the venom of *Vespa magnifica*. MP-VBs (vespa mastoparan) and VESP-VBs (vespa chemotactic peptide) were purified from the venom of the wasp *Vespa bi‐ color* Fabricius and demonstrated antimicrobial action [198]. The amphipathic α-helical structure and net positive charge (which permits electrostatic interaction with the negatively charged microbial cell membrane) of mastoparan appear to be critical for MCD activity and because of these structural properties, mastoparans are often highly active against the cell membranes of bacteria, fungi, and erythrocytes, as well as mast cells [199].

### **6.4. Toxins acting on inflammatory and nociceptive responses**

Bee venom has been used in Oriental medicine and evidence from the literature indicates that bee venom plays an anti-inflammatory or anti-nociceptive role against inflammatory re‐ actions associated with arthritis and other inflammatory diseases [200]. Bee venom demon‐ strated neuroprotective effect against motor neuron cell death and suppresses neuroinflammation-induced disease progression in symptomatic amyotrophic lateral sclero‐ sis (ALS) mice model [200]. Melittin has effects on the secretion of phospholipase A2 and in‐ hibits its enzymatic activity, which is important because phospholipases may release arachidonic acid which is converted into prostaglandins [201]. Have also been reported that melittin decreased the high rate of lethality, attenuated hepatic inflammatory responses, al‐ leviated hepatic pathological injury and inhibited hepatocyte apoptosis. Protective effects were probably carried out through the suppression of NF-jB activation, which inhibited TNF-α liberation. Therefore, melittin may be useful as a potential therapeutic agent for at‐ tenuating acute liver injury [202]. In addition of melittin, others agents has shown anti-in‐ flammatory activity. Among them are adolapin and MCDP. Adolapin showed marked antiinflammatory and anti-nociceptive properties due to inhibition of prostaglandin synthase system [203]. MCDP, isolated of *Apis mellifera* venom, is a strong mediator of mast cell de‐ granulation and releases histamine at low concentrations [204].

#### **6.5. Toxins acting on immunological system**

from wasp venoms of *V. magnifica*, is very similar to other (PLA1), especially to other wasp allergen PLA1. Magnifin can activate platelet aggregation and induce thrombosis *in vivo*. It was the first report of PLA1 from wasp venoms that can induce platelet aggregation [193].

An Integrated View of the Molecular Recognition and Toxinology - From Analytical Procedures to Biomedical

Antimicrobial peptides have attracted much attention as a novel class of antibiotics, espe‐ cially for antibiotic-resistant pathogens. They provide more opportunities for designing nov‐ el and effective antimicrobial agents [194]. Melittin has various biological, pharmacological and toxicological actions including antibacterial and antifungal activities [195]. Bombolitin (structural and biological properties similar to those of melittin), isolated from the venom of *B. ignitus* worker bees, possesses antimicrobial activity and show inhibitory effects on bacte‐ rial growth for Gram-positive, Gram-negative bacteria and fungi, suggesting that bomboli‐ tin is a potential antimicrobial agent [196]. Osmin, isolated of solitary bee *Osmia rufa*, shows some similarities with the mast cell degranulation (MCD) peptide family. Free acid and Cterminally amidated osmins were chemically synthesized and tested for antimicrobial and haemolytic activities. Antimicrobial and antifungal tests indicated that both peptides were able to inhibit bacterial and fungal growth [197]. Two families of bioactive peptides which belongs to mastoparans (12a and 12b) and chemotactic peptides (5e, 5g and 5f) were purified and characterized from the venom of *Vespa magnifica*. MP-VBs (vespa mastoparan) and VESP-VBs (vespa chemotactic peptide) were purified from the venom of the wasp *Vespa bi‐ color* Fabricius and demonstrated antimicrobial action [198]. The amphipathic α-helical structure and net positive charge (which permits electrostatic interaction with the negatively charged microbial cell membrane) of mastoparan appear to be critical for MCD activity and because of these structural properties, mastoparans are often highly active against the cell

membranes of bacteria, fungi, and erythrocytes, as well as mast cells [199].

Bee venom has been used in Oriental medicine and evidence from the literature indicates that bee venom plays an anti-inflammatory or anti-nociceptive role against inflammatory re‐ actions associated with arthritis and other inflammatory diseases [200]. Bee venom demon‐ strated neuroprotective effect against motor neuron cell death and suppresses neuroinflammation-induced disease progression in symptomatic amyotrophic lateral sclero‐ sis (ALS) mice model [200]. Melittin has effects on the secretion of phospholipase A2 and in‐ hibits its enzymatic activity, which is important because phospholipases may release arachidonic acid which is converted into prostaglandins [201]. Have also been reported that melittin decreased the high rate of lethality, attenuated hepatic inflammatory responses, al‐ leviated hepatic pathological injury and inhibited hepatocyte apoptosis. Protective effects were probably carried out through the suppression of NF-jB activation, which inhibited TNF-α liberation. Therefore, melittin may be useful as a potential therapeutic agent for at‐ tenuating acute liver injury [202]. In addition of melittin, others agents has shown anti-in‐ flammatory activity. Among them are adolapin and MCDP. Adolapin showed marked antiinflammatory and anti-nociceptive properties due to inhibition of prostaglandin synthase

**6.4. Toxins acting on inflammatory and nociceptive responses**

**6.3. Toxins with antibiotic activity**

Applications

38

Characterization of the primary structure of allergens is a prerequisite for the design of new diagnostic and therapeutic tools for allergic diseases. Major allergens in bee venom (recog‐ nized by IgE in more than 50% of patients) include phospholipase A2 (PLA2), acid phospha‐ tase, hyaluronidase and allergen C, as well as several proteins of high molecular weights (MWs) [205]. Besides these, Api m 6, was frequently (42%) recognized by IgE from bee ven‐ om hypersensitive patients [206]; from wasp venom were purified Vesp c 1 (phospholipase A1) and Vesp c 5 (antigen-5) from *Polistes gallicus*, and Vesp ma 2 and Vesp ma 5 from *Vespa magnifica*, [207-208]. Formulations of poly(lactic-co-glycolic acid) (PLGA) microspheres rep‐ resent a strategy for replacing immunotherapy in multiple injections of venom. The results obtained with bee venom proteins encapsulated showed that the allergens may still be effec‐ tive in the induction of an immune response and so may be a new formulation for VIT [209]. Recombinant proteins with immunosuppressive properties have been reported in the litera‐ ture, such as rVPr1 and rVRr3, identified, cloned and expressed from isolated VPR1 and VPr2 from *Pimpla hypochondriaca* [210]. Chemotactic peptide protonectin 1-6 (ILGTIL-NH2) was detected in the venom of the social wasp *Agelaia pallipes pallipes* [211]. Polybia-MPI and Polybia-CP were isolated from the venom of the social wasp *Polybia paulista* and character‐ ized as chemotactic peptides for PMNL cells [212]. Under the diagnosis, the microarray was reported. Protein chips can be spotted with thousands of proteins or peptides, permitting to analyses the IgE responses against a tremendous variety of allergens. First attempts to mi‐ croarray with Hymenoptera venom allergens included Api m 1, Api m 2, Ves v 5, Ves g 5 and Pol a 5 in a set-up with 96 recombinant or natural allergen molecules representative of most important allergen sources. The venom allergens from different bee, wasp and ant spe‐ cies can be offered on a single chip, allowing to differentiate the species that has stung based on species-specific markers. The allergen microarray allows the determination and monitor‐ ing of allergic patients' IgE reactivity profiles to large numbers of disease-causing allergens by using single measurements and minute amounts of serum [213].

#### **6.6. Toxins with anticancer and cytotoxic activities**

Bee venom is the most studied among the arthropods covered in this chapter regarding its anti-cancer activities, due mainly to two substances that have been isolated and character‐ ized: melittin and phospholipase A2 (PLA2). Melittin and PLA2 are the two major compo‐ nents in the venom of the species *Apis mellifera* [214]. Melittin is inhibitor of calmodulin activity and is an inhibitor of cell growth and clonogenicity of human and murine leukemic cells [215]. Study indicated that key regulators in bee venom-induced apoptosis are Bcl-2 and caspase-3 in human leukemic U937 cells through down-regulation of the ERK and Akt signal pathway [216]. Furthermore recent reports indicate that BV is also able to inhibit tu‐ mor growth and exhibit anti-tumor activity *in vitro* and *in vivo* and can be used as a chemo‐ therapeutic agent against malignancy [217]. The adjuvant treatment with PLA2 and

phosphatidylinositol-(3,4)-bisphosphate was more effective in the blocking of tumor cell growth [218]. New peptides have been isolated from bee venom and tested in tumor cells, exhibiting promising activities in the treatment of cancer. Lasioglossins isolated from the venom of the bee *Lasioglossum laticeps* exhibited potency to kill various cancer cells *in vitro* [219]. Briefly the bee venom acts inhibiting cell proliferation and promoting cell death by different means: increasing Ca2+ influx; inducing cytochrome C release; binding calmodulin; decreasing or increasing the expression of proteins that control cell cycle or activating PLA2, causing damage to cell membranes interfering in the apoptotic pathway [220]. Among po‐ tential anticancer compounds, one of the most studied is mastoparan, peptide isolated from wasp venom that has been reported to induce a potent facilitation of the mitochondrial per‐ meability transition. It should be noted that this recognized action of mastoparan is marked at concentrations <1 μM [221]. Two novel mastoparan peptides, Polybia-MP-II e Polybia-MP-III isolated from venom of the social wasp *Polybia paulista*, exhibited hemolytic activity on erythrocytes [222]. Polybia-MPI, also was purified from the venom of the social wasp *P. paulista*, synthesized and studied its antitumor efficacy and cell selectivity. Results revealed that polybia-MPI exerts cytotoxic and antiproliferative efficacy by pore formation and have relatively lower cytotoxicity to normal cells [223].

**7.1. Toxins acting on cardiovascular system**

sine) with antiplatelet activity were detected [237].

**7.3. Toxins with antibiotic activity**

**7.2. Toxins acting on hemostasis**

A study showed that the *Lonomia obliqua* caterpillar bristles extract (LOCBE) directly releas‐ es kinin from low-molecular weight kininogen, being suggested that kallikrein-kinin system plays a role in the edematogenic and hypotensive effects during *L. obliqua* envenomation [231].

Toxins from Venomous Animals: Gene Cloning, Protein Expression and Biotechnological Applications

http://dx.doi.org/10.5772/52380

41

There are numerous studies in literature reporting the effects on the hemostatic system of toxins from caterpillars. The effect of a crude extract of spicules from *Lonomia obliqua* cater‐ pillar on hemostasis was found to activate both prothrombin and factor X [232]. Lopap is a prothrombin activator isolated from the bristles of *L. obliqua* caterpillar. Lopap demonstrated ability to induce activation, expression of adhesion molecules and to exert an anti-apoptotic effect on human umbilical vein endothelial cells [233]. Lonofibrase, an α-fibrinogenase from *L. obliqua* was isolated from venomous secretion [234]. Losac, a protein with procoagulant activity, which acts as a growth stimulator and an inhibitor of cellular death for endothelial cells, was purified of the bristle extract of *L. obliqua*. Losac may have biotechnological appli‐ cations, including the reduction of cell death and consequently increased productivity of an‐ imal cell cultures [235]. Lonomin V, serine protease isolated from *Lonomia achelous* caterpillar, inhibited platelet aggregation, probably caused by the degradation of collagen. It is emphasized that Lonomin V shows to be a potentially useful tool for investigating cellmatrix and cell-cell interactions and for the development of antithrombotic agents in terms of their anti-adhesive activities [236]. The venom from the tropical ant, *Pseudomyrmex triplar‐ inus*, inhibited arachidonic acid and induced platelet aggregation, suggesting that venom prevented the action of prostaglandins. The venom was fractionated and factor F (adeno‐

Venom alkaloids from *Solenopsis invicta,* fire ant, inhibit the growth of Gram-positive and Gram-negative bacteria and presumably act as a brood antibiotic. Peptides named poneri‐ cins were identified from the venom of ant *Pachycondyla goeldii*. Fifteen peptides were classi‐ fied into three different families according to their primary structure similarities: ponericins G, W, and L. Ponericin G1, G3, G4 and G6 demonstrated antimicrobial activity. Ponericins G share about 60% sequence similarity with cecropins and these have a broad spectrum of ac‐ tivity against bacteria. Peptides family W shares about 70% sequence similarity with Gae‐ gurin 5 (*Rana rugosa*) and melittin (discussed in previous topics). Gaegurin 5 exhibits a broad spectrum of antimicrobial action against bacteria, fungi, and protozoa and has very little hemolytic action. The ponericin L2 from the third family has only an antibacterial ac‐ tion, and shares important sequence similarities with dermaseptin 5, which has strong anti‐ microbial action against bacteria, yeast, fungi, and protozoa [238]. A cytotoxic peptide from the venom of the ant *Myrmecia pilosula*, Pilosulin 1, was identified as a potential novel anti‐ microbial peptide sequence. It outlined a potent and broad spectrum antimicrobial activity including standard and multi-drug resistant gram-positive and gram-negative bacteria and

### **6.7. Toxins with insulin releasing activity**

Bee venom inhibits insulitis and development of diabetes in non-obese diabetic (NOD) mice. The cumulative incidence of diabetes at 25 weeks of age in control was 58% and NOD mice bee venom treated was 21% [224]. Mastoparan, component of wasp venom, is known to af‐ fect phosphoinositide breakdown, calcium influx, exocytosis of hormones and neurotrans‐ mitters and stimulate the GTPase activity of guanine nucleotide-binding regulatory proteins [225]. Thus, it is reported in the literature that mastoparan stimulates insulin secretion in hu‐ man, as well as in rodent. Furthermore, glucose and alpha-ketoisocaproate (alfa-KIC) in‐ crease the mastoparan-stimulated insulin secretion [226].
