Bee Venom Toxic Effect on MDA-MB-231 Breast Cancer Cells and Caenorhabditis Elegans

INTRODUCTION

Bee venom has therapeutics and pharmacological properties. Further toxicological studies on animal models are necessary due to the severe allergic reactions caused by this product.

METHOD

Here, Caenorhabditis elegans was used as an in vivo toxicity model, while breast cancer cells were used to evaluate the pharmacological benefits. The bee venom utilized in this research was collected from Apis mellifera species found in Northeast Brazil. The cytotoxicity caused by bee venom was measured by MTT assay on MDA-MB-231 and J774 A.1 cells during 24 - 72 hours of exposure. C. elegans at the L4 larval stage were exposed for three hours to M9 buffer or bee venom. Survival, behavioral parameters, reproduction, DAF-16 transcription factor translocation, the expression of superoxide dismutase (SOD), and metabolomics were analyzed. Bee venom suppressed the growth of MDA-MB-231 cancer cells and exhibited cytotoxic effects on macrophages. Also, decreased C. elegans survival impacted its behaviors by decreasing C. elegans feeding behavior, movement, and reproduction.

RESULTS

Bee venom did not increase the expression of SOD-3, but it enhanced DAF-16 translocation from the cytoplasm to the nucleus. C. elegans metabolites differed after bee venom exposure, primarily related to aminoacyl- tRNA biosynthesis, glycine, serine and threonine metabolism, and sphingolipid and purine metabolic pathways. Our findings indicate that exposure to bee venom resulted in harmful effects on the cells and animal models examined.

CONCLUSION

Thus, due to its potential toxic effect and induction of allergic reactions, using bee venom as a therapeutic approach has been limited. The development of controlled-release drug strategies to improve this natural product's efficacy and safety should be intensified.

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.

Mechanism of antimicrobial activity of honeybee (Apis mellifera) venom on Gram-negative bacteria: Escherichia coli and Pseudomonas spp

Honeybee venom (Apitoxin, BV), a secretion substance expelled from the venom gland of bees, has being reported as antimicrobial against various bacterial species; however, the mechanism of action remains uncharacterized. In this study, the antibacterial activity of BV was investigated on hygiene indicator Escherichia coli and the environmental pathogen and spoilage bacterial species, Pseudomonas putida and Pseudomonas fluorescens. An array of methods was combined to elucidate the mode of action of BV. Viability by culture on media was combined with assessing cell injury with flow cytometry analysis. ATP depletion was monitored as an indicator to metabolic activity of cells, by varying BV concentration (75, 225and 500 µg/mL), temperature (25 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^\circ \complement $$\end{document}∘∁ and 37 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^\circ \complement $$\end{document}∘∁), and time of exposure (0 to 24 h). Venom presented moderate inhibitory effect on E. coli by viability assay, caused high membrane permeability and significant ATP loss where the effect was increased by increased concentration. The viability of P. putida was reduced to a greater extent than other tested bacteria at comparable venom concentrations and was dictated by exposure time. On the contrary, P. fluorescens appeared less affected by venom based on viability; however, flow cytometry and ATP analysis highlighted concentration- and time-dependent effect of venom. According to Transmission Electron Microscopy results, the deformation of the cell wall was evident for all species. This implies a common mechanism of action of the BV which is as follows: the cell wall destruction, change of membrane permeability, leakage of cell contents, inactivation of metabolic activity and finally cell death.

Emerging therapeutic modality enhancing the efficiency of chemotherapeutic agents against head and neck squamous cell carcinoma cell lines

The current work aimed to evaluate bee venom (BV) cytotoxic effect and its synergistic action when combined with cisplatin (CIS) against four types of head and neck squamous cell carcinoma (HNSCC) cell lines. 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cell viability, reverse transcription-polymerase chain reaction (RT-PCR) for expression of BCL2 associated X (BAX), B-cell lymphoma 2 (BCL2) and epidermal growth factor receptor (EGFR) genes and, flow cytometry for cell cycle analysis were performed. MTT assay revealed that BV caused an approximately 50% cell death for UMSCC12, UMSCC29, UMSCC38 and, UMSCC47 cell lines after 72 hr with 54.809 µg/ml, 61.287 µg/ml, 71.328 µg/ml and, 61.045 µg/ml, respectively. RT-PCR demonstrated a significant up-regulation of BAX gene and a significant down-regulation of BCL2 and EGFR genes among single or combined treatments with CIS and BV as compared to vehicle-treated. The cell lines treated with both BV and CIS showed marked elevation of BAX and a notable drop of BCL2 and EGFR expressions than single-treated groups. Cell cycle analysis via flow cytometry revealed significantly increased cells in the G2/M phase in single or combined-treated cell lines with CIS and BV when compared with vehicle-treated. Moreover, a significant decrease in cells in S phases among all single and combined treatments when matched with vehicle-treated. Briefly, the findings of the present study suggest that BV can exert an anti-cancer effect on HNSCC and may have the potentiality for potentiation of CIS cytotoxic effects and reduction of its adverse effects.

Antimicrobial activity of apitoxin from Apis mellifera in Salmonella enterica strains isolated from poultry and its effects on motility, biofilm formation and gene expression

Salmonella is a major global food-borne pathogen. One of the main concerns related to Salmonella and other food-borne pathogens is their capacity to acquire antimicrobial resistance and produce biofilms. Due to the increased resistance to common antimicrobials used to treat livestock animals and human infections, the discovery of new antimicrobial substances is one of the main challenges in microbiological research. An additional challenge is the development of new methods and substances to inhibit and destruct biofilms. We determined the antimicrobial and antibiofilm activities of apitoxin in 16 Salmonella strains isolated from poultry. In addition, the effect of apitoxin on Salmonella motility and the expression of biofilm- and virulence-related genes was evaluated. The minimum inhibitory concentrations (MIC) of apitoxin ranged from 1,024-256 μg/mL, with 512 μg/mL being the most common. Sub-inhibitory concentrations of apitoxin significantly reduced biofilm formation in 14 of the 16 Salmonella strains tested, with significant increases in motility. MIC concentrations of apitoxin destroyed the pre-formed biofilm by 27.66-68.22% (47.00% ± 10.91). The expression of biofilm- and virulence-related genes and small RNAs was differentially regulated according to the strain and the presence of apitoxin. The transcription of the small RNAs dsrA and csrB, related to antimicrobial resistance, was upregulated in the presence of apitoxin. We suggest that apitoxin is a potential antimicrobial substance that could be used in combination with other substances to develop new drugs and sanitizers against food-borne pathogens.