Propolis is a resinous mixture that honey bees collect from tree buds, sap flows, or other botanical sources. It is used as a sealant for unwanted open spaces in the hive. Propolis is used for small gaps (approximately 6 millimeters (0.24 in) or less), while larger spaces are usually filled with beeswax. Its color varies depending on its botanical source, the most common being dark brown. Propolis is sticky at and above room temperature (20 Â°C). At lower temperatures, it becomes hard and very brittle.
Propolis is also believed to promote heart health and strengthen the immune system. One study has shown that it reduced the chances of cataracts in rat pups. Old beekeepers recommend a piece of propolis kept in the mouth as a remedy for a sore throat. Propolis lozenges and tinctures can be bought in many countries. Though claims have been made for its use in treating allergies, propolis may cause severe allergic reactions if the user is sensitive to bees or bee products.
Some of these claims are being clinically investigated and several studies are published in the biomedical literature. Since the chemical composition of propolis varies depending on season, bee species and geographic location, caution must be applied in extrapolating results (as above).
As an antimicrobial
As an emollient
As an immunomodulator
As a dental antiplaque agent
Propolis is a subject of recent dentistry research, since there is some evidence that propolis may actively protect against dental caries and other forms of oral disease, due to its antimicrobial properties. Propolis can also be used to treat canker sores. Its use in canal debridement for endodontic procedures has been explored in Brazil.
As an antitumor growth agent
Propolis' use in inhibiting tumorigenesis has been studied in mice in Japan.In pre-clinical models of human breast cancer, propolis induces cell cycle arrest, apoptosis and reduces expression of growth and transcription factors, including NF-κB. Notably, caffeic acid phenethyl ester down-regulates mdr-1 gene, considered responsible for the resistance of cancer cells to chemotherapeutic agents.