Propolis or bee glue 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 °C (68 °F). At lower temperatures, it becomes hard and very brittle.
For centuries, beekeepers assumed that bees sealed the beehive with propolis to protect the colony from the elements, such as rain and cold winter drafts. However, 20th-century research has revealed that bees not only survive, but also thrive, with increased ventilation during the winter months throughout most temperate regions of the world.
Propolis is now believed to:
- reinforce the structural stability of the hive;
- reduce vibration;
- make the hive more defensible by sealing alternative entrances;
- prevent diseases and parasites from entering the hive, and to inhibit fungal and bacterial growth;
- prevent putrefaction within the hive. Bees usually carry waste out of and away from the hive. However, if a small lizard or mouse, for example, finds its way into the hive and dies there, bees may be unable to carry it out through the hive entrance. In that case, they would attempt instead to seal the carcass in propolis, essentially mummifying it and making it odorless and harmless.
The composition of propolis varies from hive to hive, from district to district, and from season to season. Normally, it is dark brown in color, but it can be found in green, red, black, and white hues, depending on the sources of resin found in the particular hive area. Honey bees are opportunists, gathering what they need from available sources, and detailed analyses show that the chemical composition of propolis varies considerably from region to region, along with the vegetation. In northern temperate climates, for example, bees collect resins from trees, such as poplars and conifers (the biological role of resin in trees is to seal wounds and defend against bacteria, fungi and insects). "Typical" northern temperate propolis has approximately 50 constituents, primarily resins and vegetable balsams (50%), waxes (30%), essential oils (10%), and pollen (5%). Propolis also contains persistent lipophilic acaricides, a natural pesticide that deters mite infestations.
In neotropical regions, in addition to a large variety of trees, bees may also gather resin from flowers in the genera Clusia and Dalechampia, which are the only known plant genera that produce floral resins to attract pollinators. Clusia resin contains polyprenylated benzophenones. In some areas of Chile, propolis contains viscidone, a terpene from Baccharis shrubs, and in Brazil, naphthoquinone epoxide has recently been isolated from red propolis, and prenylated acids such as 4-hydroxy-3,5-diprenyl cinnamic acid have been documented. An analysis of propolis from Henan, China found sinapinic acid, isoferulic acid, caffeic acid, and chrysin, with the first three compounds demonstrating antibacterial properties. Also, Brazilian red propolis, largely derived from Dalbergia ecastaphyllum plant resin, has high relative percentages of the isoflavonoids 3-hydroxy-8,9-dimethoxypterocarpan and medicarpin. Other flavonoids commonly present include galangin and pinocembrin. Caffeic acid phenethyl ester (CAPE) is also a component of some varieties of propolis from New Zealand.
Occasionally, worker bees will even gather various caulking compounds of human manufacture, when the usual sources are more difficult to obtain. The properties of the propolis depend on the exact sources used by each individual hive; therefore any potential medicinal properties that may be present in one hive's propolis may be absent from another's, or from another sample in the same hive.
The National Institutes of Health rates propolis as "possibly effective" for treating cold sores, genital herpes, and post-surgery mouth pain. Currently, there is "insufficient evidence" to rate the effectiveness of propolis in treating other conditions.
Propolis is the focus of a large number of research projects. Some preliminary research findings (published in the biomedical literature), together with their limitations, are described below.
Preliminary scientific studies show some types of propolis have in vitro antibacterial and antifungal activity with active constituents including flavonoids like galangin and hydroxycinnamic acids like caffeic acid. In the absence of any in vivo or clinical studies however, it is not clear if this antimicrobial activity has any therapeutic relevance.
Preliminary in vivo studies with rats suggest propolis may be effective in treating the inflammatory component of skin burns. Also, a clinical trial has shown Brazilian propolis skin cream to be superior to silver sulfadiazine for the treatment of partial thickness burn wounds. Recent studies have raised concerns about the efficacy of silver sulfadiazine, however, and suggest that it may actually delay wound healing. Further clinical research is needed.
Propolis has been reported to exhibit both immunosuppressive and immunostimulant effects. Further research is needed to establish if there is a practical application for these seemingly opposing pharmacological effects.
Propolis has been the subject of recent dentistry research, and there is some in vivo and clinical evidence that propolis might protect against dental caries and other forms of oral disease, due to its antimicrobial properties. Propolis is also being investigated for its efficacy in the treatment of canker sores and in reducing the inflammation associated with canal debridement and endodontic procedures.
One in vivo study has shown that propolis reduced the chances of cataracts in rat pups. Again however, in the absence of any clinical studies, it is not clear if this activity has any therapeutic relevance.
In in vitro tests, propolis induces cell cycle arrest, apoptosis and reduces expression of growth and transcription factors, including NF-κB. Notably, caffeic acid phenethyl ester down-regulates the mdr-1 gene, considered responsible for the resistance of cancer cells to chemotherapeutic agents. In in vivo studies with mice, propolis inhibits 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced tumorigenesis. Once again, in the absence of any clinical studies, it is not clear if this activity has any therapeutic relevance.
In musical instruments
Propolis is used by most stringed instrument makers (violin, viola, cello and bass) to enhance the appearance of the wood grain. It is a component of some varnishes and its distinctive smell is easily recognizable in a luthier's shop. Propolis was purportedly used by Antonio Stradivari in the varnish of his instruments.
Propolis is used by some chewing gum manufacturers to make propolis gum.
- Discussion of bee space in the beehive article.
- R Krell 1996. value-added products from beekeeping FAO AGRICULTURAL SERVICES BULLETIN No. 124 Food and Agriculture Organization of the United Nations Rome
- Simone-Finstrom, Michael; Spivak, Marla (May–June 2010). "Propolis and bee health: The natural history and significance of resin use by honey bees". Apidologie 41 (3): 295–311. doi:10.1051/apido/2010016.
- Walker, Matt (23 July 2009). "Honeybees sterilise their hives". BBC News. Retrieved 2009-07-24.
- Toreti VC; Sato HH; Pastore GM; Park YK (2013). "Recent progress of propolis for its biological and chemical compositions and its botanical origin". Evidence-Based Complementary and Alternative Medicine 2013: 697390. doi:10.1155/2013/697390. PMID 23737843.
- Joint FAO/WHO Expert Committee on Food Additives. Meeting (2008: Geneva, Switzerland). Evaluation of certain veterinary drug residues in food: 70th report of the Joint FAO/WHO Expert Committee on Food Additives. (WHO technical report series; no. 954)
- Mesquita, R. C. G.; Franciscon C. H. (June 1995). "Flower visitors of Clusia nemorosa G. F. W. Meyer (Clusiaceae) in an Amazonian white-sand Campina". Biotropica 27 (2): 254–8. doi:10.2307/2389002. JSTOR 2389002.
- Tomás-Barberán, F. A.; García-Viguera C.; Vit-Oliviera P.; Ferreres F. et al. (1993-08-03). "Phytochemical evidence for the botanical origin of tropical propolis from Venezuela". Phytochemistry 34 (1): 191–6. doi:10.1016/S0031-9422(00)90804-5.
- Scott Armbruster, W. (September 1984). "The Role of Resin in Angiosperm Pollination: Ecological and Chemical Considerations". American Journal of Botany 71 (8): 1149–60. doi:10.2307/2443391. JSTOR 2443391.
- Bankova, V. (February 2005). "Recent trends and important developments in propolis research". Evidence-based Compl. and Alt. Medicine 2 (1): 29–32. doi:10.1093/ecam/neh059. PMC 1062152. PMID 15841275. Retrieved 2008-05-17.
- Montenegro G; Mujica AM; Peña RC; Gómez M et al. (2004). "Similitude pattern and botanical origin of the Chilean propolis". Phyton 73: 145–154. ISSN 1851-5657.
- Trusheva, B.; Popova, M.; Bankova, V.; Simova, S. et al. (2006). "Bioactive Constituents of Brazilian Red Propolis" (PDF). Evidence-Based Complementary and Alternative Medicine 3 (2): 249–254. doi:10.1093/ecam/nel006. PMC 1475931. PMID 16786055.
- Park, Y. K.; Alencar, S. M.; Aguiar, C. L. (2002). "Botanical Origin and Chemical Composition of Brazilian Propolis". Journal of Agricultural and Food Chemistry 50 (9): 2502–2506. doi:10.1021/jf011432b. PMID 11958612.
- Qiao Z; Chen R (August 1991). "[Isolation and identification of antibiotic constituents of propolis from Henan]". Zhongguo Zhong Yao Za Zhi (in Chinese) 16 (8): 481–2, 512. PMID 1804186.
- Silva, B. B.; Rosalen, P. L.; Cury, J. A.; Ikegaki, M. et al. (2008). "Chemical Composition and Botanical Origin of Red Propolis, a New Type of Brazilian Propolis". Evidence-Based Complementary and Alternative Medicine 5 (3): 313–316. doi:10.1093/ecam/nem059. PMC 2529384. PMID 18830449.
- Cushnie TPT; Lamb AJ (2005). "Antimicrobial activity of flavonoids" (PDF). International Journal of Antimicrobial Agents 26 (5): 343–356. doi:10.1016/j.ijantimicag.2005.09.002. PMID 16323269.
- Demestre M, Messerli SM, Celli N et al. (August 2008). "CAPE (caffeic acid phenethyl ester)-based propolis extract (Bio 30) suppresses the growth of human neurofibromatosis (NF) tumor xenografts in mice". Phytother Res 23 (2): 226–30. doi:10.1002/ptr.2594. PMID 18726924.
- Fearnely J. (2001) Bee propolis. Souvenir Press Ltd. London
- "Propolis:MedlinePlus Supplements". U.S. National Library of Medicine. January 19, 2012.
- Sforcin, J.M.; Bankova V. (2011-01-27). "Propolis: is there a potential for the development of new drugs?". T Ethnopharmacol 133 (2): 253–60. doi:10.1016/j.jep.2010.10.032. PMID 20970490.
- Orsi, R. O.; Sforcin J. M.; Rall V. L. M.; Funari S. R. C. et al. (2005). "Susceptibility profile of Salmonella against the antibacterial activity of propolis produced in two regions of Brazil". Journal of Venomous Animals and Toxins including Tropical Diseases 11 (2): 109–16. doi:10.1590/S1678-91992005000200003. Retrieved 2008-01-14.
- Cafarchia C; De Laurentis N; Milillo MA; Losacco V et al. (1999). "Antifungal activity of Apulia region propolis". Parassitologia 41 (4): 587–590. PMID 10870567.
- Cushnie TPT; Lamb AJ (2005). "Detection of galangin-induced cytoplasmic membrane damage in Staphylococcus aureus by measuring potassium loss". Journal of Ethnopharmacology 101 (1-3): 243–248. doi:10.1016/j.jep.2005.04.014. PMID 15985350.
- Hoşnuter, M.; Gürel A.; Babucçu O.; Armutcu F. et al. (March 2004). "The effect of CAPE on lipid peroxidation and nitric oxide levels in the plasma of rats following thermal injury". Burns 30 (2): 121–5. doi:10.1016/j.burns.2003.09.022. PMID 15019118.
- Ocakci, A.; Kanter M.; Cabuk M.; Buyukbas S. (October 2006). "Role of caffeic acid phenethyl ester, an active component of propolis, against NAOH-induced esophageal burns in rats". Int J Pediatr Otorhinolaryngol. 70 (10): 1731–9. doi:10.1016/j.ijporl.2006.05.018. PMID 16828884.
- Gregory, S. R.; Piccolo N.; Piccolo M. T.; Piccolo M. S. et al. (February 2002). "Comparison of propolis skin cream to silver sulfadiazine: a naturopathic alternative to antibiotics in treatment of minor burns". J Altern Complement Med. 8 (1): 77–83. doi:10.1089/107555302753507203. PMID 11890438.
- Brätter, C.; Tregel M.; Liebenthal C.; Volk H. D. (October 1999). "Prophylactic effectiveness of propolis for immunostimulation: a clinical pilot study". Forsch Komplementarmed. 6 (5): 256–60. PMID 10575279.
- Ansorge, S.; Reinhold D.; Lendeckel U. (July–August 2003). "Propolis and some of its constituents down-regulate DNA synthesis and inflammatory cytokine production but induce TGF-beta1 production of human immune cells". Z Naturforsch [C] 58 (7–8): 580–9. PMID 12939048.
- Brovko, T. E.; Kravchuk P. A. (July–August 1970). "Two cases of allergic reaction after administration of propolis drugs". Zh Ushn Nos Gorl Bolezn 30 (4): 102–3. PMID 5503978.
- Botushanov, P. I.; Grigorov G. I.; Aleksandrov G. A. (2001). "A clinical study of a silicate toothpaste with extract from propolis". Folia Med (Plovdiv) 43 (1–2): 28–30. PMID 15354462.
- Koo, H.; Cury J. A.; Rosalen P. L.; Ambrosano G. M. et al. (November–December 2002). "Effect of a mouthrinse containing selected propolis on 3-day dental plaque accumulation and polysaccharide formation". Caries Research 36 (6): 445–8. doi:10.1159/000066535. PMID 12459618.
- Duarte, S.; Rosalen P. L.; Hayacibara M. F.; Cury J. A. et al. (January 2006). "The influence of a novel propolis on mutans streptococci biofilms and caries development in rats". Arch Oral Biol. 51 (1): 15–22. doi:10.1016/j.archoralbio.2005.06.002. PMID 16054589.
- Park, Y. K.; Koo M. H.; Abreu J. A.; Ikegaki M. et al. (January 1998). "Antimicrobial activity of propolis on oral microorganisms". Curr Microbiol. 36 (1): 24–8. doi:10.1007/s002849900274. PMID 9405742.
- Samet, N.; Laurent C.; Susarla S. M.; Samet-Rubinsteen N. (June 2007). "The effect of bee propolis on recurrent aphthous stomatitis: a pilot study". Clin Oral Investig. 11 (2): 143–7. doi:10.1007/s00784-006-0090-z. PMID 17285269.
- da Silva, F. B.; Almeida J. M.; Sousa S. M. (April–June 2004). "Natural medicaments in endodontics - a comparative study of the anti-inflammatory action" (PDF). Braz Oral Res. 18 (2): 174–9. doi:10.1590/s1806-83242004000200015. PMID 15311323. Retrieved 2008-01-14.
- Orhan, H.; Marol S.; Hepşen I. F.; Sahin G. (1999-12-06). "Effects of some probable antioxidants on selenite-induced cataract formation and oxidative stress-related parameters in rats". Toxicology 139 (3): 219–32. doi:10.1016/S0300-483X(99)00128-6. PMID 10647922.
- Wu, J.; Omene, C.; Karkoszka, J.; Bosland, M. et al. (September 2011). "Caffeic Acid Phenethyl Ester (CAPE), Derived from a Honeybee Product Propolis, Exhibits a Diversity of Anti-tumor Effects in Preclinical Models of Human Breast Cancer". Cancer Letters 308 (1): 43–53. doi:10.1016/j.canlet.2011.04.012. PMC 3144783. PMID 21570765.
- Sugimoto Y; Iba Y; Kayasuga R et al. (April 2003). "Inhibitory effects of propolis granular A P C on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis in A/J mice". Cancer Lett. 193 (2): 155–9. doi:10.1016/S0304-3835(03)00016-8. PMID 12706872.
- Gambichler T; Boms S; Freitag M (April 2004). "Contact dermatitis and other skin conditions in instrumental musicians". BMC Dermatol. 4: 3. doi:10.1186/1471-5945-4-3. PMC 416484. PMID 15090069.
- "Landau Carriage of 1743". Retrieved 2011-03-08.
- "Pete’s 53’ contains Propolis". Retrieved 2011-03-08.
- "GuruWax blend of propolis". Retrieved 2011-03-08.
- "Propolis when heated cause the wax to set-up". Retrieved 2011-03-08.
|Wikimedia Commons has media related to Propolis.|
|Look up propolis in Wiktionary, the free dictionary.|
- "Propolis". New International Encyclopedia. 1905.
- Farooqui, T; Farooqui, AA (2012). "Beneficial effects of propolis on human health and neurological diseases". Frontiers in bioscience (Elite edition) 4: 779–93. PMID 22201913.