Propolis
The word pro-polis, in the face of the polis, unequivocally expresses how superior it was already regarded as a defensive outpost from the time of ancient Greece. Propolis is a substance that bees produce mainly between August and October, to protect the hive, making hives among the most sterile environments in nature! The raw material of propolis is nothing but the resin produced by trees, which is collected and processed by bees with their salivary secretions to make it further effective in disinfection. Such resin, the raw material of propolis, is a substance produced by plants to protect themselves from diseases and pests: when a tree is attacked or damaged, it produces this resin with which it goes to heal and seal the part in question, to avoid contracting infections and being attacked by fungi. Similarly, when pests attack the tree, the plant contracts them by producing resin that goes to kill the insects and their larvae.
Bees collect resins from some specific types of trees based on the geobotanical area in which the hive is located. In Italy, the most common plants are: conifers (firs, pines), poplars, beeches, ash trees, horse chestnuts, alders, birches, willows and oaks. The resin collected by bees is transformed into propolis by their digestive secretions, the addition of wax and pollen. Once it is ready, it is used to seal the hive, to cover the access to the hive as well as the points of most passage, so as to disinfect bees entering and leaving and neutralize infectious and harmful agents. It is also used as a protective coating on eggs and larvae, in cells and to disinfect animal corpses, which have penetrated the hive. What has been enunciated so far highlights how formidable nature is, always evolving, not only with propolis, which, however, provides an unparalleled example. Propolis is composed of resins and balms 50-55 %, wax 25-30 %, essential oil 10 %, organic and mineral substances 5 %. The most studied active ingredients are flavonoids (galangin, apigenin, quercetin, chrysin, pinocembrin); aromatic acids (caffeic, ferulic, benzoic, cinnamic); mineral salts, trace elements, (aluminum, barium, chromium, cobalt, manganese, copper, zinc, iron, nickel, silicon).
Manifests antibacterial property toward numerous microbial strains: the essential oil showed antibacterial activity, even at very low doses, toward gram-positive and gram-negative bacteria. Among the flavonoids, galangin and pinocembrin showed high antimicrobial activity (especially toward gram positives). The mechanism of action of propolis on bacterial cells is complex; the cytoplasm, plasma membrane, and cell wall are disorganized, by lysis and protein inhibition, due to action on the dna-dependent rna-polymerase of bacteria is also prevented from separating daughter cells. Experimental studies, in mice, have shown that propolis stimulates the phagocytic activity of macrophages, the phagocytic stimulus was double in treated mice compared with the control group. In addition, propolis has been shown to inhibit the growth of several species of fungi and yeasts, such as candida albicans, microsporum canis, and trichophyton. It appears that the antifungal activity is similar to that of amphotericin b, which forms complexes with sterols (ergosterol) of fungal membranes.
Several studies have shown the antiviral activity of propolis against influenza a and b viruses, parainfluenza, herpes simplex, adenovirus, and respiratory syncytial virus. Anti-inflammatory and antioxidant properties are attributed to flavonoids. It may also be useful on gastric ulcer and gastritis (probably due to action against helicobacter) and other gastrointestinal tract disorders (colitis, diarrhea, diverticulosis). Propolis also has healing, re-epithelializing properties that combined with the others, described above make it an excellent remedy for numerous external and oral mucosal disorders (in addition to typical throat sprays, also touches on canker sores, gingivitis). It finds use in therapy in acute and chronic bronchitis, influenza, genito-urinary infections, angina, pharyngitis, nasopharyngitis, laryngitis, gingival inflammation.
NOTES
Propolis may cause allergic phenomena in particularly sensitive individuals (e.g., those who already have allergies to cosmetics and particularly to allergens contained in essential oils that may also be contained in propolis). Since it is impossible to determine a priori the composition of propolis, which varies depending on what is collected by the bees, for these individuals it may be a good idea to test whether there may be allergic sensitivity to propolis by placing a drop on the inside of the elbow or behind the ear, where the skin is most sensitive; if after a few hours the skin becomes reddened, it is very likely that an allergic reaction may develop.
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