1 Life
and Health Sciences Research Institute (ICVS), School of Health
Sciences, University of Minho, Braga, Portugal
2 ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
3 CBMA - Centre of Molecular and Environmental Biology, Biology Department, University of Minho, Braga, Portugal
4 Chemistry Centre Vila Real (CQVR), University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
2 ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
3 CBMA - Centre of Molecular and Environmental Biology, Biology Department, University of Minho, Braga, Portugal
4 Chemistry Centre Vila Real (CQVR), University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
BMC Complementary and Alternative Medicine 2013, 13:184
doi:10.1186/1472-6882-13-184
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1472-6882/13/184
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1472-6882/13/184
| Received: | 5 September 2012 |
| Accepted: | 5 July 2013 |
| Published: | 19 July 2013 |
© 2013 Valença et al.; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background
Propolis is a resin collected by bees from plant buds and exudates, which is further
processed through the activity of bee enzymes. Propolis has been shown to possess
many biological and pharmacological properties, such as antimicrobial, antioxidant,
immunostimulant and antitumor activities. Due to this bioactivity profile, this resin
can become an alternative, economic and safe source of natural bioactive compounds.
Antitumor action has been reported in vitro and in vivo for propolis extracts or its isolated compounds; however, Portuguese propolis has
been little explored. The aim of this work was to evaluate the in vitro antitumor activity of Portuguese propolis on the human colon carcinoma cell line
HCT-15, assessing the effect of different fractions (hexane, chloroform and ethanol
residual) of a propolis ethanol extract on cell viability, proliferation, metabolism
and death.
Methods
Propolis from Angra do Heroísmo (Azores) was extracted with ethanol and sequentially
fractionated in solvents with increasing polarity, n-hexane and chloroform. To assess
cell viability, cell proliferation and cell death, Sulforhodamine B, BrDU incorporation
assay and Anexin V/Propidium iodide were used, respectively. Glycolytic metabolism
was estimated using specific kits.
Results
All propolis samples exhibited a cytotoxic effect against tumor cells, in a dose-
and time-dependent way. Chloroform fraction, the most enriched in phenolic compounds,
appears to be the most active, both in terms of inhibition of viability and cell death.
Data also show that this cytotoxicity involves disturbance in tumor cell glycolytic
metabolism, seen by a decrease in glucose consumption and lactate production.
Conclusion
Our results show that Portuguese propolis from Angra do Heroísmo (Azores) can be a
potential therapeutic agent against human colorectal cancer.
