Effects of propolis and CAPE on proliferation and apoptosis of McCoy-Plovdiv cell line.
The mechanisms of action of propolis can be studied in detail by comparing the effects of propolis and the effects of its constituent components.


OBJECTIVE
To clarify and compare the effects of Bulgarian propolis and caffeic acid phenethyl ester (CAPE, a chemically synthesized component of propolis)--by using a set of cellular, molecular-biological and immunological techniques.


METHODS
The McCoy-Plovdiv cell line was treated with propolis and CAPE in increasing concentrations (0.01, 0.1, 1.0, 10 mg/L, and 2.5, 4, 8, 16 mg/L, respectively). The expression of the proliferating cell nuclear antigen (PCNA) and the tumour-suppressor protein p53 was studied immunocytochemically. Apoptosis was measured using a highly sensitive microgel electrophoresis technique (comet assay).


RESULTS
The results of the study showed corresponding changes in the expression of the examined proliferative antigens. PCNA was detected in all examined concentrations of the tested substances the expression being dose-dependent. Molecule localization changed from the nucleus to the cytoplasm. Treatment with CAPE brought about gradual attenuation of PCNA expression. High propolis concentrations induced increased synthesis of p53. No p53 expression was found when cells were treated with CAPE. The studied substances in their highest concentrations (10 mg/L propolis and 16 mg/L CAPE) had a cytotoxic effect. The comet assay showed DNA degradation kinetics characteristic for apoptosis.


CONCLUSIONS
The present study demonstrates that high concentrations of propolis and CAPE cause apoptosis-induced cell death in McCoy-Plovdiv cells.
Department of Biology, Medical University, Plovdiv, Bulgaria.
Milena N
MN
Draganova-Filipova
Milena G
MG
Georgieva
Ekaterina N
EN
Peycheva
George A
GA
Miloshev
Victoria S
VS
Sarafian
Lyudmil P
LP
Peychev
D017209:Apoptosis / Q000187:drug effects*; D002109:Caffeic Acids / Q000494:pharmacology*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000494:pharmacology; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D011429:Propolis / Q000494:pharmacology*; D013583:Synovial Membrane / Q000166:cytology; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D002109:Caffeic Acids; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53; D011429:Propolis; C055494:caffeic acid phenethyl ester; D010626:Phenylethyl Alcohol