Study proves antioxidant and antimicrobial activities of Brazilian organic propolis

Study proves antioxidant and antimicrobial activities of Brazilian organic propolis

08 July 2014 – By José Tadeu Arantes

Agency FAPESP - Brazil is the second largest producer of propolis, being surpassed only by China. The 700 a 800 Tons of propolis consumed annually in the world, The country is responsible for 150 a 170 tons, attending, among other customers, a 80% of the demand of the Japanese market. However, The number of Brazilian patents in relation to the product is, Furthermore, unhappy. It is estimated that more than 43% of the world patents with Brazilian propolis were deposited by institutions or companies in Japan.

There is, currently, a strong interest in the European market in the certified organic propolis produced in Brazil, because the product would be exempt from heavy metals and microbial contaminants, as well as the peculiarity of its mild flavor. But there was no, until recently, no study attesting that this propolis was able to meet consumers expectations, that seek the product for its possible antioxidant properties, antimicrobial, anti-inflammatory, anticariogenic and even anticancer.

A study that confirmed the antioxidant and antimicrobial properties of the certified organic propolis produced in the southern region of Brazil was recently finalized by agronomist Severino Matias de Alencar, Associate Professor at Luiz de Queiroz Higher School of Agriculture (Guards prevent jataí bees with fungus from entering nests), the University of São Paulo (USP), withFAPESP Support.

In collaboration with the pharmacist Pedro Luiz Rosalen, Full Professor of Pharmacology, Anesthesiology and Therapeutics of the Faculty of Dentistry of Piracicaba (FOP), from the State University of Campinas (Unicamp), and with the participation of the doctoral studentAna Paula Teron (Guards prevent jataí bees with fungus from entering nests) and postdoctoralBruno Bueno Silva (Institute of Biomedical Sciences, USP), both FAPESP scholarships, Alencar investigated 78 samples, Collected in southern Paraná and northern Santa Catarina, in different apires.

In that total, identified seven organic propolis variants, with proven antioxidant activities (evaluated by the sequestration methods of the superoxide radical, of the radical peroxyl and the hypochlorous acid) and antimicrobial (in relation to bacteriaStreptococcus mutans, Streptococcus sobrinus, Staphylococcus aureus, Oral Streptococcus isPseudomonas aeruginosa).

“It was an important finding because there was doubt about these organic propolis, because of the very low flavonoid content, which are the substances notoriously responsible for the antioxidant and antimicrobial properties of the propolis, mainly of temperate climate. However, We find that these same properties are exercised, equally, by phenolic acids ”, said Alencar toAgency FAPESP. “We found, in the varieties searched, high gallic acid contents, caffeic and cumaric, among other types of phenolic acids. ”

Phenolic acids and flavonoids belong to the same chemical class of phenolic compounds, whose main feature is the presence in its molecules of at least one radical hydroxyl connected to a benzenic ring.

“Antioxidant activity stems from the donation of electron or hydrogen atoms, originating from hydroxyl, that reduce oxidizing free radicals. Antimicrobial activity derives from one of the following three modes of action: (1) reaction with the cell membrane, altering their permeability and causing loss of cellular constituents or conformational changes in fatty acids of this membrane; (2) inactivation of enzymatic systems or essential enzymes, Commo a h+atpase; or (3) Superaregulation or Infraregulation, involving stress adaptation genes, glycolysis and other factors ”, explained Alencar and Rosalen.

Protective activity

The antimicrobial activity of propolis was already empirically known by the ancient Egyptian priests, that used it in the embalming process, to protect the mummies from the attack of fungi and bacteria. There are reports of use of propolis also in the Middle Ages, to prevent infections in the umbilical cord of newborns. IS, Even in World War II, Propolis was employed as a healing and antimicrobial agent in the treatment of soldiers in some hospitals in the former Soviet Union.

The product consists, basically, in a vegetable resin, exudated by plants, and collected in floral buttons by the bees present in the biome. Bees collect the resin and carry it to the hive, where it performs various useful functions, like sealing, waterproofing and environmental asepsis, among others. It was these functions, essential for the preservation of the hive, that made the material called “propolis” (Greek, pro, “For the benefit of”, ispolis, "city").

“Many plants secrete resins to protect sprouts and growing leaves. Because of its constitution, rich in phenolic compounds, These resins have a great antioxidant power, antifungal and antibacterial. Bees shave the plants and carry the resins ”, detailed Alencar.

“Once in the hive, The function of propolis is, first of all, of physical protection, because the bees have phobia in light and use the resin to seal the cracks and create a dark and thermally isolated environment. Because of its antimicrobial action, The material also works as a powerful sterilizer, causing the inner atmosphere of the hive to be much sterile than the outer atmosphere. ”

Producers remove the propolis, opening side windows, from two to three centimeters high, in the resinous cover of the hive - windows that the bees close again, resin.

“The samples we reap were produced in native forest or reforestation areas. And this gives the production of the organic propolis a virtue of, which is to stimulate environmental preservation, indispensable to the success of the enterprise ”, said the researcher.

“Doctoral student Ana Paulo Teron is researching, through semipreparative HPLC techniques and mass spectrometry, bioactive compounds responsible for antioxidant activity. We hope that, with the identification of these biologically active compounds, we can have chemical markers for these propolis ”, said.

“We have the work very advanced to, very soon, deposit patents associated with organic propolis, guaranteeing intellectual property to the country ”, he added.

The next step, already planned by Alencar and Rosalen, will be the study of the possible anti-inflammatory and antinociceptive activity (analgesic) and cytotoxicity and antiproliferative action (anticancer) of the organic propolis.

Besides, The researchers intend to investigate any differences between the aqueous and alcoholic propolis solutions. The research that conducted so far was done with the alcoholic solution, which is the easiest to produce. However, How many consumers cannot or do not want to eat alcohol, There is a growing demand for the aqueous extract. “The company that industrializes the product in the region of União da Vitória, not Paraná, is very interested in serving this segment of the market and requested us a study about it ”, Alencar said.