Volume 36, Issue 7, Page 18 (July 2005)

LESLIE S. BAUMANN, M.D.

DR. BAUMANN is director of cosmetic dermatology at the University of Miami. To respond to this column, or to suggest topics for future columns, write to Dr. Baumann at our editorial offices via e-mail at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Propolis, also known as bee glue, is an extract of beehives that has been used for hundreds of years in naturopathic medicine. Currently, some radiation therapists use propolis to treat actinic stomatitis and mucositis (Wurzbg. Medizinhist. Mitt. 2004;23:133–45), but this bee product is used more often for wound care and minor cutaneous indications as well as for a dietary supplement. In folk remedies, it has served as a potent anti-inflammatory agent (Cancer Res. 1993;53:1255–61) and its use dates back to ancient Greece and Rome (Wurzbg. Medizinhist. Mitt. 2004;23:133–45). In fact, the word propolis is derived from the Greek words “pro” (before) and “polis” (city), and reflects the ancient observation that bees built walls of the substance near the entrance of their hives. It was considered the third natural product of bees, in addition to honey and wax. Propolis is a resinous material that originates in the buds and barks of certain trees, mostly poplars (Wurzbg. Medizinhist. Mitt. 2004;23:133–45), and is gathered by honeybees and used inside the hive (Anticancer Res. 1996;16:2669–72). Propolis stabilizes beehives and honeycombs and protects bees against cold weather and potential intruders (Wurzbg. Medizinhist. Mitt. 2004;23:133–45).

In traditional medicine, propolis was most successful in treating a wide range of wounds because of its antiedematous and anti-infectious properties, presumably. Propolis was also used in the ancient world for muscle, tendon, and joint pain. More germane to this column, bee glue was used to treat cutaneous conditions such as lichens and condylomata (Wurzbg. Medizinhist. Mitt. 2004;23:133–45).

In a recent study, investigators evaluated the reputed antimicrobial, anti-inflammatory, and scar-healing capacity of a high-grade Brazilian propolis cream. Patients presenting with bilateral superficial second degree burns over less than 20% of their body surface—with wounds of similar depth and quality—were admitted into the study within 48 hours of their injuries and then treated with propolis cream on one wound and silver sulfadiazene (SSD) applied to a similar wound on the other side. Wounds were debrided and dressings changed on the following morning. Patients returned to the clinic at 3-day intervals to have their wounds checked and dressings changed, with reapplication of the ointment taking place only at these visits. In addition, investigators cultured the wounds for microbial growth and took photographs to record inflammation and scar formation. No significant differences were noted in microbial colonization, but wounds treated with the propolis cream showed less inflammation and quicker scar formation, compared with the SSD-treated burns. While noting the beneficial effects of propolis on burns, the researchers speculated that more frequent changing of wound dressings would have evinced antimicrobial results also (J. Altern. Complement. Med. 2002;8:77–83).

Propolis was recently evaluated for efficacy in the treatment of recurrent genital herpes simplex virus type 2. Ninety adults, all with local symptoms, participated in a randomized, single-blind, masked-investigator, controlled study at seven medical centers in which Canadian propolis ointment containing natural flavonoids was compared with ointments of acyclovir and placebo, with 30 people randomized to each group. Study ointments were applied four times daily. Participants were examined on the 3rd, 7th, and 10th days of treatment for clinical symptoms, including the number and size of herpetic lesions, with lesions classified into four stages: vesicular, ulcerated, crusted, and healed. On day 3, 15 members of the propolis group had crusted lesions as opposed to 8 in the acyclovir group and 0 on placebo. Local symptoms were noted in three propolis group members, eight acyclovir individuals, and nine on placebo. On day 7, healing was observed in 10 propolis patients, 4 acyclovir patients, and 3 in the placebo group. Investigators reported that 24 propolis patients and 14 acyclovir patients healed by day 10. Overall, the propolis ointment was considered more effective in healing lesions and reducing local symptoms (Phytomedicine 2000;7:1–6). In an earlier study of 65 patients, a topical ointment containing propolis (Nivcrisol-D) showed a significant therapeutic effect against recurrent herpes and zona zoster, with patients who used the study drug healing from outbreaks in an average of 4 days, while patients using placebo took an average of 8 days to heal from outbreaks (Virologie 1988;39:21–4).

Various components of propolis have also been isolated and found to possess anticarcinogenic properties. Flavonoid aglycones are some of the significant constituents of propolis that are believed to contribute antitumorigenic properties (Anticancer Res. 1996;16:2669–72). A study with a fractionated methanol extract of a Brazilian propolis resulted in the isolation of a tumoricidal substance characterized as a new clerodane diterpenoid, which reduced the growth and number of skin tumors induced by 7,12-dimethylbenz(a)anthracene (DMBA) application on mouse back skin by inhibition of DNA synthesis (Anticancer Res. 1996;16:2669–72).

In a study to determine whether caffeic acid phenethyl ester (CAPE), a propolis constituent, inhibits the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced processes associated with carcinogenesis, low doses of CAPE were topically applied to SENCAR mice. CAPE was found to strongly inhibit several TPA-mediated oxidative processes considered sine qua non for tumor promotion, including polymorphonuclear leukocyte infiltration into mouse skin and ears; hydrogen peroxide (H2O2) production; and formation of oxidized bases in epidermal DNA. In addition, researchers noted inhibition of edema and ornithine decarboxylase induction in CD-1 and SENCAR mice after CAPE application, as well as the inhibition of TPA-induced H2O2 production in bovine lenses. Researchers concluded that CAPE appears to have potent chemopreventive capacity, particularly in treating disorders associated with strong inflammatory and/or oxidative stress processes, such as cancer and cataracts (Cancer Res. 1993;53:1255–61).

In a different study on skin tumors, CD-1 mice were initiated with DMBA and then treated twice weekly with topically applied TPA, resulting in 18.8 skin papillomas per mouse. Subsequent topical application of CAPE to the backs of the mice together with TPA twice a week for 20 weeks inhibited the number of skin papillomas and reduced tumor size in a dose-dependent manner. The same combination also decreased the level of 5-hydroxymethyl-2' deoxyuridine (HMdU) in epidermal DNA produced through the previous initiation with DMBA. In addition, in vitro CAPE introduction to cultured HeLa cells inhibited DNA, RNA, and protein synthesis. All of these inhibitory effects conferred by CAPE were deemed by investigators to be potent (Carcinogenesis 1996;17:761–5).

In a more recent study on polyphenolic compounds and antitumorigenic properties, a water-soluble derivative of propolis, caffeic acid (CA), CAPE, and quercetin administered to mice resulted in a reduction in the number of lung tumor nodules. Researchers related the antitumor properties of the tested substances to their immunomodulatory capacity, cytotoxicity to tumor cells, and ability to induce apoptosis and necrosis, suggesting that propolis, CA, CAPE, and quercetin show promising potential for combating tumor growth (J. Ethnopharmacol. 2004;94:307–15).

There are several commercially available products—such as creams, shampoos, lipsticks, toothpastes, and mouthwashes—that contain propolis as an active ingredient. It is also used as a dietary supplement.

Conclusion

Although the body of research on propolis is comparatively meager at the present time, the reports on this resinous substance appear very promising. I am particularly encouraged by the reports on its potential uses as an anticarcinogenic agent and an antiherpetic agent. Of course, much more research, in the form of randomized, controlled trials, is needed prior to incorporating propolis into the armamentarium as a first-line therapy. Given its historical or traditional uses, propolis is probably more effective in that context as compared with its use as an ingredient in new topical cosmeceuticals. In the latter case, research and efficacy remain to be established.

PII: S0037-6337(05)70376-4

doi:10.1016/S0037-6337(05)70376-4

© 2005 Elsevier Inc. All rights reserved.