In vitroantibacterial effect of wasp (Vespa orientalis) venom

Background The emergence of antibacterial resistance against several classes of antibiotics is an inevitable consequence of drug overuse. As antimicrobial resistance spreads throughout the globe, new substances will always be necessary to fight against multidrug-resistant microorganisms. Venoms of many animals have recently gained attention in the search for new antimicrobials to treat infectious diseases. Thefore, the present study aimed to study the antibacterial effects of wasp (Vespa orientalis) crude venom. Two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram-negative ones (Escherichia coli and Klesiella pneumonia) were compared for their sensitivity to the venom by determining the inhibition zone (Kirby-Bauer method) and minimum inhibitory concentration (MIC). A microbroth kinetic system based on continuous monitoring of changes in the optical density of bacterial growth was also used for determination of antimicrobial activity.Results The venom exhibited a well-recognized antimicrobial property against the tested bacterial strains. The inhibition zones were determined to be 12.6, 22.7, 22.4 and 10.2 mm for S. aureus, B. subtilis,E. coliand K. pneumonia, respectively. The corresponding MIC values were determined to be 64, 8, 64 and 128 μg/mL, respectively. The MIC50 and MIC90 values of the venom were respectively determined to be 63.6 and 107 μg/mL for S. aureus, 4.3 and 7.0 μg/mL for B. subtilis, 45.3 and 65.7 μg/mL for E. coli and 74.4 and 119.2 μg/mL for K. pneumonia. Gram-positive bacteria were generally more sensitive to the venom than gram-negative ones.Conclusions Results revealed that the venom markedly inhibits the growth of both gram-positive and gram-negative bacteria and could be considered a potential source for developing new antibacterial drugs

In vitro antihistamine-releasing activity of a peptide derived from wasp venom of Vespa orientalis

Objective: To investigate the antihistamine-releasing effect of a peptide isolated from wasp venom of Vespa orientalis. Methods: This peptide was separated from crude venom by chromatography methods and mass spectrometry. Then various concentrations (2, 4, 8, 16, 32, 64, 128 and 256 μmol/L) of the peptide were incubated with mast cells and lactate dehydrogenase assay was performed. Results: No significant effect was observed in lactate dehydrogenase absorbance under 128 μmol/L concentration. This implied that the peptide did not cause cell death in mast cells and consequently, histamine release did not happen. Moreover, the results showed the IC50 of mast cells degranulation at 126 μmol/L, which was approximately high implying that this peptide had high selectivity for normal cells and did not cause histamine release from these cells. Conclusions: This would be a great aim in new drug development, in which an agent acts potentially on its target tissue without activating the immune system