INTRODUCTION

One of the novel strategies in cancer treatment is the combination of conventional chemotherapeutic drugs and natural products. In a previous study, co-treatment of the anti-cancer drug cyclophosphamide (CP) with honey from giant honey bee (Apis dorsata) resulted to a dose-dependent increase in its cytotoxic effect in human lung carcinoma (A549) cells. However, the molecular mechanism of this combinatorial effect remains unknown.

OBJECTIVES

In this study, the effect of A. dorsata honey on the expression of selected CYP450 genes at the mRNA level, as well as the proapoptotic gene CASP8 and antiapoptotic gene BCL2 was investigated in CP-treated A549 cells.

METHODS

MTT Assay was performed to determine the cell viability of A549 cells after treatment with CP with or without A. dorsata honey, as well as the EC50 of CP with honey thereafter. RT-qPCR was then performed to study the effect of A. dorsata honey on the expression of selected CYP450 genes as well as CASP8 and BCL2 genes in CPtreated A549 cells. LC-MS was carried out to screen for putative compounds in A. dorsata honey which may possibly have anti-cancer activity.

RESULTS

Honey in the lowest concentration (0.6% v/v) most effectively enhanced the cytotoxic effect of CP. CYP2J2 and CYP1B1 indicated a 2.38-fold and 1.49-fold upregulation, respectively as compared to untreated cells. This cytotoxic effect is further enhanced by upregulation of CASP8 that is paralleled by a downregulation of BCL2. Phytosphingosine and sphinganine are honey constituents which may be linked to the increased cytotoxicity of CP observed in A549 cells.

CONCLUSION

This study provides further knowledge on the molecular basis by which A. dorsata honey potentiates the cytotoxic effect of cyclophosphamide in A549 cells.

Cyclophosphamide ; Lc-ms ; Liquid Chromatography-mass Spectrometry ; Apoptosis

Background: The escape of polyethylene microbeads from waste-water treatment facilities to aquatic habitats has been a major concern by scientific communities due to the adverse effects on aquatic organisms as well as the well-being of the marine and terrestrial ecosystems. Objective: This study was conducted to evaluate the embryotoxic and teratogenic effects of polyethylene microbeads on the early development of the zebrafish Danio rerio using the Fish Embryo Acute Toxicity Test (FET). Methodology: Sixty (60) zebrafish embryos were exposed to polyethylene microbead suspensions (PE-MBS) of 20 μg/L, 200 μg/L, and 2000 μg/L concentrations. Using FET, the toxicological endpoints (i.e., egg coagulation, lack of somite formation, non-detachment of tail, and lack of heartbeat) were observed every 24 hours until the 96th-hour exposure. Hatching of the embryo from the chorion was observed from 48-96 hpf (hours-post fertilization), and at least four parameters of teratogenicity (i.e., edema of the pericardium and yolk sac, bent axis, tail curvature, and collapsed swim bladder) was observed at 144 hpf. Results: Significant differences between means and variances in the embryotoxic and teratogenic effects were observed for all treatment groups in relation to the negative control (reconstituted water). The emulsifier control (0.01% Tween 80, p-value=0.9), the solvent control (1% DMSO, p-value = 0.9), and the 20 μg/L PE-MBS (p-value = 0.92) did not significantly differ with the negative control group. However, the positive control (5% ethanol, pvalue= 7.8) and 200 μg/L (p-value = 1.1), and 2000 μg/L (p-value = 1.48) of PE-MBS were significantly embryotoxic and teratogenic to the developing organism. Conclusion The high concentrations of PE-MBS (200 μg/L and 2000 μg/L) may induce early hatching, mortality, and malformations. Tukey Kramer post hoc test substantiated that PE-MBS toxicity is dose-dependent since embryotoxicity and teratogenicity increase at higher concentrations. Further studies should be conducted to know more about the adverse effects of polyethylene microbeads on the development, physiology, and genomics of freshwater fishes.
Zebrafish