Propolis: chemical diversity and challenges in quality control

Abstract

Propolis is a resinous natural product produced by honeybees using beeswax and plant exudates. The chemical composition of propolis is highly complex, and varies with region and season. This inherent chemical variability presents several challenges to its standardisation and quality control. The present review was aimed at highlighting marker compounds for different types of propolis, produced by the species Apis mellifera , from different geographical origins and that display different biological activities, and to discuss strategies for quality control. Over 800 compounds have been reported in the different propolises such as temperate, tropical, birch, Mediterranean, and Pacific propolis; these mainly include alcohols, acids and their esters, benzofuranes, benzopyranes, chalcones, flavonoids and their esters, glycosides (flavonoid and diterpene), glycerol and its esters, lignans, phenylpropanoids, steroids, terpenes and terpenoids. Among these, flavonoids (> 140), terpenes and terpenoids (> 160) were major components. A broad range of biological activities, such as anti-oxidant, antimicrobial, anti-inflammatory, immunomodulatory, and anticancer activities, have been ascribed to propolis constituents, as well as the potential of these compounds to be biomarkers. Several analytical techniques, including non-separation and separation methods have been described in the literature for the quality control assessment of propolis. Mass spectrometry coupled with separation methods, followed by chemometric analysis of the data, was found to be a valuable tool for the profiling and classification of propolis samples, including (bio)marker identification. Due to the rampant chemotypic variability, a multiple-marker assessment strategy considering geographical and biological activity marker(s) with chemometric analysis may be a promising approach for propolis quality assessment. Supplementary Information The online version contains supplementary material available at 10.1007/s11101-022-09816-1.

Antibiofilm and Anti-Quorum Sensing Potential of Cycloartane-Type Triterpene Acids from Cameroonian Grassland Propolis: Phenolic Profile and Antioxidant Activity of Crude Extract

“…Natural products and phytochemicals seem to be a remedy, and they are being investigated for their abilities to disrupt quorum sensing networks and bacterial biofilm formation. Propolis is a bioactive substance that is usually consumed as fractions or crude extracts due to its health benefits, and it is necessary to continuously report its chemical composition so to ensure quality control, safety, and therapeutic efficacy [ 83 ]. The antimicrobial activity of propolis on microorganisms, either gram-positive or gram-negative, has been extensively evaluated and reported with few papers on their effects on biofilms and quorum sensing.…”

Molecular and Cellular Mechanisms of Propolis and Its Polyphenolic Compounds against Cancer

“…It also includes a number of genetic and epigenetic modifications that affect the regulation of cell proliferation and survival, such as deregulated CpG dinucleotide methylation and aberrant histone acetylation that can impair the immunogenic potential of cancer cells. During the multistage processes of tumor formation, cancer cells acquire specific properties that differentiate them from healthy cells: resistance to growth inhibition, growth-factor independent proliferation, ongoing replication, escape from apoptosis, migration, invasion, formation of metastasis, and support of angiogenesis [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ].…”

“…Among other health-promoting biological activities, products rich in flavonoids exert strong immunopotentiatory effects and antitumor activities. Honey, propolis, and royal jelly, all products collected by bees, contain numerous phenolic compounds that have beneficial effects on human health [ 5 , 6 , 7 , 8 ]. The concentration of flavonoids, which represent the majority of phenolic bioactive molecules in honeybee products, depends on various factors, including plant species used, health of the plant, season, environmental factors, and geographical origin, among others [ 5 , 6 , 7 , 8 ].…”

Perspectives for Uses of Propolis in Therapy against Infectious Diseases

“…Propolis composition is highly variable, depending on several factors, such as the geographic location of the hives, season of the year, and characteristics of the local vegetation [ 13 ]. Such variability represents a challenge for standardization and quality control of propolis [ 14 ]. In addition to plant resins and beeswax, propolis contains pollen [ 15 ].…”

“…Several reviews have been published about types of propolis, respective plant sources of resin, composition, and biological activities (e.g., [ 9 ]). Propolis resin has a complex composition, comprising over 800 components, considering propolis types from all geographic regions [ 14 ]. The main components of most propolis types are phenolic compounds.…”