Propolis is a resinous substance derived from tree saps and plant resins gathered by honeybees from leaf buds and other botanical sources. Bees will employ a variety of plant and tree species for obtaining propolis, depending on what species are growing within the vicinity of the hives, so chemical composition of propolis varies widely between different locations and ecosystems.
It is a heterogeneous, multifunctional material used in the hive as a sanitising sealant and waterproofing agent, and has been shown to be highly effective against the pathogen of chalkbrood disease, Ascosphera apis. It has a long history of use as a folk remedy and unlike other so called ‘natural’ remedies it has an expansive database on its biological activity to indicate its medicinal and therapeutic potential. Propolis contains a vast range of compounds such as flavonoids, terpenoids, organic acids and phytosterols, with over 300 different compoinds identified so far, with large variation in chemistry depending on geographic location from where the propolis is derived. Propolis samples analyzed from many different parts of the world, and with differing chemistries, demonstrate potent antioxidant and antimicrobial activity which indicates wherever honeybees are they will obtain the highest quality plant resins available to them in their local respective ecosystems. These chemical constituents come from the gathered plant resins and substances secreted by the bees. A number of different compounds in propolis exert biological activity, and of key importance and are the phenolic flavonoid compounds and it appears that the mixture of chemical compounds in propolis and the synergy between them is what makes it a substance of general pharmacological value existing as a natural mixture.
Propolis itself has negligible toxicity, no side effects, is non irritating and has no risk of overdose, with an LD50 of 7.34g/Kg weight in mice. This would be an estimated LD50 of 50g of propolis for a 160 pound person. Furthermore, there may be a synergy when propolis is ingested alongside other rejuvenating beehive products such as raw honey, bee pollen or royal jelly.
A tiny proportion of people may be allergic to propolis, and these people may experience dermatitis if used topically. While this is rare, care must be taken with people new to using it, with a small amount tested for individual tolerance.
Propolis is reported to have antibacterial, antiviral and antifungal effects. While the chemical composition of propolis can vary significantly between locations, these effects seem to apply to propolis from diverse geographic regions. Propolis also has antioxidant, anti-inflammatory, antitumor, antiulcer, hepatoprotective and immunostimulating effects. Over many millions of years of evolution, trees and plants have been selected to produce these defensive resins, and in turn bees have been driven to invest energy in gathering these resins which indicates how important and useful this material is to them, and this potential may also be applicable to Man. Moreover, bees in different parts of the world will employ different botanical sources for propolis, with analysis of Brazilian propolis revealing that the chemistry is markedly different to European propolis, but that the antibiotic activity of both types is very similar. The antibiotic properties of propolis indicate it has potential as a natural and safe food preservative agent and disinfectant. This range of beneficial effects indicates propolis has great potential as an agent aiding in healing and tissue regeneration.
The antibacterial activity of propolis is one of the reasons it is employed in the hive, for sanitising the hive and preventing infection with so many thousands of bees all living within close proximity of each other. It is so effective in this way that it can be used as an embalming agent for creatures that enter the hive die or are killed in defence by the bees and are too large to be removed. It has been shown to be effective in the control of the bacterium Staphyloccus aureus, (commonly linked with cases of atopic dermatitis and food poisoning), including the antibiotic resistant MRSA strains, Mycobacterium tuberculosis, Escherichia coli, Salmonella and Helicobacter pylori, which is commonly associated with gastric ulcers. An important consideration is that propolis has been shown to be effective in treating a number of antibiotic resistant strains of these latter and other bacterial species. Propolis shows promise in the treatment of upper respiratory tract infections, significantly reducing both the incidence of such infections, while also reducing recovery time. It has a number of antibacterial effects, interfering with bacterial cell division and metabolism. Thus propolis acts as much more complex and multifaceted antibacterial agent than any prescription antibiotic or drug and has great potential to enhance antibacterial therapy.
Studies have found propolis to be effective in the treatment of the Influenza and the Herpes simplex viruses. This indicates that propolis may be a useful agent in the prevention and treatment of the common cold and flu, and propolis has long been used as a traditional remedy for sore throats by beekeepers. Furthermore, it may prove to be synergistic with other treatments for colds and flu that have shown clinical promise such as Echinacea. Research indicates that compounds in propolis may suppress HIV-1 replication. This, coupled with its demonstrated immune system boosting effects, suggest that propolis may provide invaluable support therapy for those suffering from AIDS.
Propolis shows potential in the treatment of pathogenic Candida fungi and may prove effective against fungicide-resistant fungal strains while enhancing the activity of antifungal agents. There is potential for some of the antifungal compounds in propolis to be employed in agroecosystems, with reduced ecological and economic costs when compared to existing fungicides.
Propolis may also exert beneficial anti-protozoan effects, and ethanolic extract of propolis has been found to strongly inhibit infection levels of macrophages and heart muscle cells by bloodstream trypomastigotes, of the species Trypanosoma cruzi and be lethal to Trichomonas vaginalis. The former species is responsible for trypanosomiasis in both humans and animals in America, and in humans is known as Chagas disease. This indicates that propolis may have application as an antitrypanosomal agent. This is of particular interest, as there is no current effective therapy for the treatment of chronic cases of Chagas disease.
There are a number of antibiotic compounds in propolis, that will also vary in their proportions and types between different locales, times and hives. Thus propolis may be a potent agent against pathogens, as it will likely be harder for these organisms to gain resistance to a complex and ever varying chemical cocktail, when compared to a single isolated drug. In addition, propolis extracts have been found to have a powerful synergistic effect when combined with antibiotics and antimicrobial drugs, particularly those that interfere with bacterial protein synthesis. Thus propolis is capable of acting as a standalone antibacterial agent, but combined with antibiotics, dosages of these chemicals can be lowered and so reduce the risk of side effects associated with antibiotics, while also decreasing the chances of drug resistance.
Propolis can be employed as a general health tonic for otherwise healthy individuals, as and when desired, and it is suitable for sustained or daily use. It is suitable as a broad spectrum nutritional supplement, being a rich source of a number of vitamins, minerals and trace elements. It has been demonstrated to have immune system boosting effects, being a significant activator of white blood cells. In addition it has anti-inflammatory and antioxidant effects. Research also indicates that the phenolic compounds in propolis such as flavonoids may have liver protective properties, including against alcohol toxicity. This is of interest, as liver disease, particularly relating to alcohol damage, is one of the UK’s biggest killers and fastest rising diseases. Propolis may also provide antimutagenic effects against a number of different environmental mutagens.
Flavonoid compounds within propolis may be of benefit to those who live active life styles and athletes. Research indicates that caffeic acid phenethyl ester (CAPE), a common and widespread botanical compound and component of propolis, significantly reduces hyperthermal stress on immune cells. This suggests that a propolis supplement would be valuable to endurance athletes as it would protect immune cells while acting as an antioxidant agent against exercise generated free radicals.
These anti-inflammatory effects of propolis extract and isolated CAPE appear to offer powerful protection to cartilage during inflammatory joint diseases and may be a potent aid for sufferers of arthritis and aid in a faster healing of damaged bone tissue. CAPE has been found to a potent suppresser of cells which break down bone tissue. Bone destructive diseases such as osteoporosis are caused in part by imbalances in bone resorption and bone formation. Research on CAPE indicates it could be potential treatment for osteolytic bone wasting diseases and it may reduce bone wasting associated with aging.
These powerful antioxidant effects may exert a neuroprotective influence and be of benefit to sufferers of diabetes, with research on animal models indicating propolis scavenges free radicals and has a stabilising effect on blood sugars and lipids. In turn this may exert a protective effect on the heart, with animal models indicating propolis reduces oxidative stress on cardiac tissue, while having an antihypertensive effect while also lowering blood cholesterol levels.
Propolis has been shown to inhibit tumour production, due to a range of biological effects it has on tumour cells. CAPE has been shown to act as a powerful antioxidant and anti-inflammatory agent and to down-regulate a gene in animal models which is thought responsible for the resistance of cancer cells to chemotherapeutic agents. Both CAPE and full spectrum propolis extract has also shown to have strong inhibitory effects against several types of cancers and can inhibit cancer cell growth via increasing the process of natural cell death and inducing direct cytotoxic effects on tumour cells. It exhibits a potent effect against the spread of cancer in the body and has been shown to markedly inhibit the invasive capacity of malignant cells.
Propolis extract also seems to markedly sensitize cancer cells to naturally occurring anticancer agents within the body, and may have a role in chemoprevention of malignant tumours and as an adjunct to chemotherapeutic treatment. Other compounds within propolis have also shown potential in cancer treatment such as Artepillin C, which has been demonstrated to exert a cytotoxic effect against malignant tumour cells while activating the immune system. Furthermore, propolis extract has been shown to significantly decrease the toxicity of chemotherapeutic agents, such as doxorubicin, to both the heart and brain, and the liver toxicity of vinblastine and cyclophosphamide due to its potent antioxidant effect, while also offering resistance to the immunosuppression induced by the latter agent. Thus propolis may act as a supplemental buffer against the significant toxicity of these chemotherapeutic agents, particularly against cyclophosphamide which is itself a known carcinogen. It could be a highly valuable treatment and supplemental agent against cancer and for those undergoing chemotherapy and radiotherapy treatment.
Propolis has potential as a dental antiplaque agent due to its antimicrobial and anti-inflammatory action. In animal research propolis has been shown to have a range of antimicrobial effects against a number of the Streptococcus bacteria species commonly associated with plaque and dental caries. Propolis tincture mixed with water and swilled in the mouth has potential as a completely natural and beneficial mouth wash, and a propolis preparation may prove effective as a toothpaste.
Propolis has been found to be effective in treating in skin burns, warts and leukoplakia and has tissue regenerative properties. It may be an invaluable treatment for sufferers of recurrent aphthous stomatitis, a common and painful ulcerative disorder of the oral cavity. It has no known cure, but preliminary clinical research involving propolis show promising results. It is non-irritating and suitable for topical use for the vast majority of people.
There is evidence from animal models to suggest that the powerful anti-inflammatory effects of propolis may benefit sufferers of radiation poisoning, by protecting against radiation responses induced by radiation exposure. Thus propolis may be a valuable supplement for those suffering from radiation poisoning or those undergoing radiotherapy for cancer treatment.
Despite such potential, there remains a considerable lack of clinical research on the effects of propolis, and there may be great potential for the development of new drugs from propolis derivatives. Further clinical research is required on the flavonoid components of propolis to fully ascertain their effectiveness when combined with chemotherapeutic agents in the treatment of human cancers. More work needs to be done to achieve standardisation of the various types of propolis, dependent on their respective botanical origins. While this inherent chemical variability is one of the main obstacles to its official acceptance into mainstream health care, it has at the same time made propolis a valuable source of novel biologically active molecules. Once some of specifics of each type of propolis relating to chemical constituents and biological activity can be evaluated, recommendations for mainstream practitioners can be made.