# Brazilian Propolis: Nature's Liquid Gold with Anti-Inflammatory and Anticancer Potential
## 3 Brazilian Propolis: Unique Properties and Economic Significance  
In the past few decades, propolis has gained significant popularity among the community of researchers. It attracted the attention of scientists as early as in the 1950s; however, it was the revelation of its healing properties that brought it widespread recognition and aroused a lot of interest [20]. After decades of thorough examination of the chemical composition of propolis, more than 300 phytochemicals have been identified in samples collected globally [20]. The chemical composition of propolis from different global regions and locations varies [21] depending on the season, the geographical factors, climate and regional botanical composition [22], which highlights the variety of vegetation in a specific area [21]. Propolis has been used as a multifaceted remedy since the ancient times and, in some countries, still remains one of the most often used medications [23]. Its versatility has been a subject of pharmacological and chemical studies for the last 30 years [23]. Regional classification of propolis samples allowed researchers to identify multiple types of propolis, each of them different in terms of medical or chemical properties and origin [23]. Poplar type propolis has buds of poplar trees (mainly the black poplar) as the main floral source and it is representative of propolis sourced from temperate zones all over the world, especially Europe [23], but also North America, non-tropical regions of Asia, New Zealand and even Africa [24]. Romanian propolis, apart from _Populus_ species, has been reported to also be derived from _Quercus_, _Aesculus_, _Ulmus_, _Pican_, _Salix_ and _Frazinus_ spp. Another commonly known variety of propolis, the Chinese type, also mainly originates from poplars; however, its unique nature is partly influenced by the surrounding environment as it is collected in mild climate conditions occurring in Central and East China [25]. Another type, Pacific propolis, also referred to as Macaranga, stems from _Macaranga_ spp. and is mostly collected in Taiwan and Okinawa [24]. Mediterranean propolis, derived from _Cupressus_ plants, is found in Malta, Creta and Sicily [24]. Apart from the aforementioned examples, other varieties of propolis, such as Turkish, Uruguayan, Polish, Nepalese, and Eucalyptus [24], have been classified. Propolis has been found to have antibacterial, antioxidative, antifungal, anti-inflammatory and anticarcinogenic properties [26; 27]. Due to the differences in chemical composition of particular types of propolis, it is rather surprising that most variants show similar biological activity. The only exception identified so far is European propolis which has been confirmed to have allergenic properties [23]. Among the identified types of propolis, the Brazilian variant is especially known for its exclusive botanical origin, content of exceptional bioactive compounds and versatile therapeutic potential. Based on the classification criteria, which include geographical origin, chemical composition, physicochemical characteristics and floral source of Brazilian propolis [28; 29], 14 types of this bee product have been distinguished [30]. Due to its diverse properties, unique chemical content and heterogenous floral and geographical origin, Brazilian propolis has drawn the attention of researchers and experts in the pharmaceutical field. Its rising popularity over the years is clearly presented in Figure 2, which shows the increasing trend based on the number of articles and reviews on Brazilian propolis and its derivatives available in the PubMed database. Duplicates and articles incorrectly assigned by the search engine were excluded. The most popular variety is green Brazilian propolis, mainly originating from _Bachatris dracunculifolia_ DC., with artepillin C being its characteristic constituent [29]. Recently, a new type of green Brazilian propolis has been discovered.