General medicinal uses of propolis include treatment of the cardiovascular and blood systems (anemia), respiratory apparatus (for various infections), dental care, dermatology (tissue regeneration, ulcers, eczema, wound healing— particularly burn wounds, mycosis, mucous membrane infections and lesions), cancer treatment, immune system support and improvement, digestive tracts (ulcers and infections), liver protection and support and many others [4].

In a study by Grange and Davey, they used a Propolis dilution of 1:20 in nutrient agar which completely inhibited the growth of S. aureaus, S. epidermidis, Enterococcus spp. Corynebacterium spp. B. catarrahlis and B. cereus. This dilution partially inhibited the growth of P. aeruginosa and E. coli but had no effect on K. pneumonia. Thus it appeared to have an inhibitory effect on cocci and gram positive rods. Tube dilution studies showed that it was bactericidal for B. cereus and the gram-negative cocci at dilutions of 1:160 to 1:320, and that growth of the H37RV reference strain of Mycobacterium tuberculosis was totally inhibited at 1:320 and partially inhibited at 1:640 dilution [5].

Koo et al. in Brazil found antibacterial effect of Propolis on S. mutans, S. sanguis and A. naeslundaii in addition to the inhibition of glycosultransferase [6].

Serkedjieva conducted an in vitro study on the antiviral activity of six synthetic substances which were esters of substituted cinnamic acids, identical with or analogous to some of the constituent fractions of Propolis. One of them, isopentyl ferculate, inhibited significantly the infectious activity of influenza virus A in vitro and the production of hemalutinins in vivo. In diverse experimental studies, it was found that the maximal inhibition of viral reproduction was observed when test substances were present in the medium during the whole infectious process [7].

Propolis and nine anti-fungal drugs were tested on four fungi that cause infections in humans. It was as effective as (or more effective than) some of the other preparations against three of the fungi, and in some tests, its activity was enhanced in the presence of propylene glycol. Propolis and propylene glycol gave better results against Scopulariopsis breveicaulis than any of the drugs tested [8].

Krol et al. described the remarkable medical property of the ethanolic extract of Propolis (EEP), that is the protection against gamma radiation. They performed their experiment on mice and found that the anti-oxidative effect could be attributed to its radical scavenging ability. They also demonstrated the ability of increasing amounts of EEP to inhibit luminol H202 chemiluminescence in vitro, and suggested that its anti-oxidative capacity was partly due to its high content of flavenoids [9].

An Italian Study investigated the antioxidant activity of a propolis extract deprived of caffeic acid phenethyl ester (CAPE). Propolis extract (with and without CAPE) and its active components showed a dose-dependent free radical scavenging effect, a significant inhibition of xanthine oxidase activity, and an antilipoperoxidative capacity. Propolis extract with CAPE was more active than propolis extract without CAPE. The experimental evidence, therefore, suggests that CAPE plays an important role in the antioxidant activity of propolis [10].

An Italian study states that this natural compound and its active principle, caffeic acid phenethyl ester (CAPE), were able to contrast the harmful effects of IL-1beta.Our data clearly demonstrated the protective action of propolis in cartilage alteration, that appears greater than that elicited by indomethacin, commonly employed in joint diseases [11].

To be effective, most vaccines typically depend on the inclusion of substances known as adjuvants that stimulate an immune response. Researchers seeking to develop a vaccine against Suid herpesvirus type1 (SuHV-1), which causes an infectious disease among swine, combined green propolis with an ethanol extract and tested it on mice. The mice showed an increased cellular immune response and increased protection against SuHV-1. This response did not occur with propolis alone, but only when the antigen was absorbed in a particulate adjuvant, like aluminum hydroxide. Thus, when associated with auxiliary substances like aluminum hydroxide, green propolis extract may increase the potency of vaccines, especially those that depend on the cellular immune response for protection [12].

Scheller demonstrated the anti-tumoral effect in mature mice bearing Ehrlich carcinoma. Survival rate after EEP treatment was compared to that of bleomycin, given alone or in combination every 2 days for thirty-six days and followed up for fourteen additional days. The survival rate at fifty days was 55% after EEP and 40% after bleomycin, while all the mice treated with EEP plus bleomycine combination demonstrated shorter survival than the controls. It was concluded that while the in vivo activity of bleomycin was reduced in the presence of cytochrome-c-reductase inhibitors (as some of the EEP components) are the anti-tumoral property of EEP in the experimental animal model studied was significant and lasting [13].

A literature review finds that propolis’s pharmacological properties make it safe and effective as an adjunct for patients receiving cancer treatment:

• Biological therapy. Biological therapy works hand in hand with the immune system. Propolis’s biological activities such as antitumoral activity, DNA protection, free-radicals scavenging, and immune stimulation act in synergy with each other and with conventional chemotherapy medication.

• Synergy with chemotherapy. Antioxidants may boost the effects of anti-carcinogenic drugs, thus enabling a decrease in the administered dose and in turn leading to a reduction in side effects. They may also influence the response to chemotherapy.

• Anti-inflammatory activity. This results from propolis’s inhibitory effect on prostaglandins, leukotrienes, and histamine release.

• Healing activity. Propolis promotes epithelial formation as well as vascular and fibroblastic neoformation of the connective tissue.

• Antimicrobial activity. Propolis’ flavonoids and phenolic acids are pharmacologically active compounds that have effects on bacteria, fungi, and viruses [14].

German study investigated the bactericidal effect against several strains isolated from patients with infections in their upper respiratory tracts [15].

Dermatological and cosmetic applications are at this time probably the most common uses for propolis and its extracts. Its effects on tissue regeneration and renovation have been well studied. Together with its bactericidal and fungicidal characteristics it provides many benefits in various applications in cosmetics [4].

In general, propolis is safe. It is a non toxic substance and for most people, will not caused irritation when used as supplements or applied to skin. However, like other honey bee products, there are people who are allergic to propolis. Allergic reaction due to this substance was first reported in beekeepers as an occupational effect but is now seen mainly in individuals who use propolis in cosmetics and supplement to treat various health conditions. It is believed that a substance called caffeic acids to be one of the causes of allergies to propolis.

•    Those allergic to pollen;

•    Asthma patients;

•    Allergic to bee stings;

•    Pregnant women.

There have not been many published clinical trials on the effect of propolis on pregnant women. Because the information in this area is limited, it has been advised to avoid using propolis during pregnancy and breastfeeding.

If allergic to propolis, it may cause redness of skin, develop rashes, swelling, itching, fluid collection, fever and may even lead skin to crack (including a severe allergic reaction called anaphylaxis). Apart from that, it may also irritate the skin area where it is applied on, cause eczema, lesions, psoriasis or mouth sores [16].

Many tinctures contain high levels of alcohol and may cause nausea or vomiting when taken with metronidazole or disulfiram. Propolis may produce additive effects when taken with antimicrobial drugs.

Propolis may interact with the following: anticoagulants, H. pylori agents, antibiotics, anti-cancer agents (antineoplastics), antifungals, anti-inflammatories, infertility agents, anti-HIV agents (antiretrovirals), immunosuppressants, and osteoporosis agents.

Balsam of Peru and propolis are both known to cause allergic sensitization in some people and have multiple compounds in common, such as benzyl benzoate, benzyl cinnamate, benzyl alcohol, benzoic acid, cinnamic acid, caffeic acid, cinnamic alcohol, and vinallin. An increased risk of allergic sensitization may occur if both products are used together [17].