Chemical and Biological Properties of Propolis from the Western Countries of the Mediterranean Basin and Portugal

The chemical composition of propolis from the western countries of the Mediterranean basin and Portugal as well as their biological attributes were reviewed. In the vast majority of these countries, extracts of propolis were predominantly constituted by phenols, with the exception of those from Malta and Sicily in which diterpenes in relative high amounts were identified. In one sample from Algeria a diterpene was also found in high concentration, nevertheless it was not determined. The identification of the components constituting essential oils were also performed but only in two countries, Portugal and Algeria, albeit with substantially different results. The biological properties reported for propolis for the western Mediterranean basin and Portugal included antimicrobial, antioxidant, antiproliferative, anti-inflammatory, neuroprotective, and protection against the side effects of some medicines (vimblastine, cyclophosphamide, paracetamol) or γ-radiation. These properties were almost always attributed to phenol acids and flavonoids. Only in very few cases diterpenes were considered responsible for such beneficial properties, particularly antibacterial activity in samples from Malta.