Chemical analysis, antioxidant, cytotoxic and antimicrobial properties of propolis from different geographic regions

Abstract

Propolis is a resinous beehive product containing functional compounds and differs based on geographical region. Physicochemical properties of each propolis effectuate their uses within modern applications. Therefore, this study was aimed to evaluate the chemical composition, antioxidant, antimicrobial, and cytotoxic activity of propolis ethanol extracts (PEE) sourced from six geographical regions. Antioxidant potency was determined using four assays: DPPH, ABTS, reducing power, and malondialdehyde inhibition (MDA). The phenolic (TPC) and flavonoid content (TFC) was calculated as gallic acid and catechol equivalents, respectively. Antimicrobial properties of propolis against pathogens and toxigenic fungi were determined using agar well diffusion assay. The cytotoxicity effect was estimated against the human dermal fibroblast (HDF) cell line using MTT assay. The results manifested propolis variations of samples, specifically for the chemical composition (p < 0.05). Omanis' propolis recorded by the highest moisture content, while the Egyptian propolis featured by high protein content. Brazilians' propolis was distinguished among samples by the highest ash content (p < 0.05). Propolis from Saudi, Omani, China, and Bulgaria represented by higher fiber content. Egyptians' propolis showed a promising antioxidant and antimicrobial potency, reflecting a high activity against food pathogen and toxigenic fungi. The IC₅₀ values of propolis samples following 24 h exposure to the normal human dermal fibroblast (HDF) cells did not show any cytotoxic effect. This study demonstrated the distinguishes between propolis sourced from different regions regarding their bioactive contents. The Egyptian's propolis can be recommended as a preservative additive that can be applied to solve numerous food safety issues.