Propolis from Turkey induces apoptosis through activating caspases in human breast carcinoma cell lines.
Propolis is a sticky substance that is collected from plants by honeybees that has anti-mutagenic and anti-carcinogenic properties with biological and therapeutic effects. The target of this study was to investigate the anti-apoptotic effect of propolis extracts (PE) on the caspase pathway in the human breast cell line MCF-7 in culture. Seven different propolis extracts, numbered PE 1-7, produced in their natural ecological environment, were collected from the Hacettepe University Beytepe Campus area in Ankara, Turkey. Individual extracts at 0.5, 0.25, 0.125 and 0.063mg/ml were incubated with MCF-7 cells during 2 days culture. Cell growth and cytotoxicity were measured colorimetrically by MTT assay. Apoptotic cell death was determined by the TUNEL method (terminal deoxynucleotidyltransferase-biotin nick end-labelling) and caspase activity was investigated by immunocytochemistry using antibodies directed against caspase 6, caspase 8 and caspase 9. The results showed that the PE 5 and 6 extracts at 0.125mg/ml dilution induced apoptosis in association with increased number of TUNEL positive cells. MTT results showed that cultures exposed to the same extracts and at the same dilution experienced better cell growth compared to those cultures exposed to the other extracts. Immunpositivity for all caspases was detected after treatment with all the extracts and at all dilutions, with stronger immunoreactivity for caspase 6 than caspases 8 and 9. Caspase 6 labelling was especially strong in PE 5 and PE 6. We conclude that propolis may have anti-tumour effects by increasing apoptosis through the caspase pathway. Such propolis extracts may be important economically and allow development of a relatively inexpensive cancer treatment.
Seda Vatansever
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H
Celal Bayar University, Faculty of Medicine, Department of Histology and Embryology, 35040 Bornova, Izmir, Manisa, Turkey. hsedav@yahoo.com
Sorkun
Kadriye
K
Ismet Deliloğlu Gurhan
S
S
Ozdal-Kurt
Feyzan
F
Turkoz
Elgin
E
Gencay
Omur
O
Salih
Bekir
B
D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology*; D020169:Caspases / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D004789:Enzyme Activation / Q000187:drug effects; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007150:Immunohistochemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011429:Propolis / Q000737:chemistry / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014421:Turkey
D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D011429:Propolis; D020169:Caspases