Ethnobotanical knowledge and utilization patterns of Burseraceae resins in Brazil

Amid all the Brazilian phytodiversity, in all its shades and shapes, black and white amorphous masses glued to the barks of Burseraceae species stand out as some of the nation's most appreciated plant medicinal resources. Burseraceae resins have been used in all macroregions of Brazil, wherever they occur, for a variety of medicinal purposes. However, despite ongoing interest in them, their cultural and health relevance in the country has been underexamined.

This review aimed to illuminate the therapeutic importance and potential of Brazilian Burseraceae by assembling the ethnomedicinal, chemical, and pharmacological data available on its resins used in Brazil.

A search for journal articles documenting local ethnomedicinal uses of Burseraceae resins and reporting chemical and pharmacological data associated with their botanical sources was conducted in ScienceDirect, Google Scholar, and PubMed databases. Books and theses were also appraised for such information.

At least 21 Burseraceae taxa, belonging to Protium, Trattinnickia, and Commiphora, are recorded as sources of medicinal resins in Brazil. Protium and Trattinickia yield oleoresins typically rich in mono- and triterpenoids, especially the pentacyclic triterpenoids α- and β-amyrin. Although Commiphora oleo-gum-resins are expected to differ significantly from Protium and Trattinickia oleoresins by the presence of gum fractions, they often exhibit distinct terpenoid compositional patterns, characterized by a high proportion of sesquiterpenoids and tetracyclic triterpenoids. Burseraceae resins are more frequently cited in the Brazilian ethnomedicinal literature for relieving headaches and healing wounds. Pharmacological evidence corroborates the potential of Burseraceae resins against these and some other conditions and diseases, however, further studies are needed to confirm their efficacy and safety when used topically and through inhalation-the two primary routes of administration explored for them in Brazil.

The present review unearths a consistent, persistent, and cross-cultural pattern of using Burseraceae resins against pain conditions. But to really tap into the Burseraceae's therapeutic potential in Brazil, we first need to address the following gaps: (a) conduct more thorough pharmacological studies, including clinical trials; (b) give more attention to the triterpenoid fraction of Burseraceae oleoresins, not only to essential oils and α- and β-amyrin; and (c) deepen our understanding of the impact of resin aging on chemical composition.