Antioxidant, antimicrobial, antiviral, and antiproliferative properties of Turkish propolis sample

Abstract

Propolis, a resinous substance collected by honeybees from various botanical sources, is known for its diverse biological activities. This study aimed to investigate the health-promoting properties of Turkish propolis by assessing its antioxidant capacity and antimicrobial activity against various pathogens. Additionally, its antiviral effects were evaluated against human herpes simplex virus type 1 (HSV-1) using MTT and quantitative real-time polymerase chain reaction (qRT-PCR) assays. The antiproliferative potential of propolis was also tested against cancer cell lines (MDA-MB-231, AR42J, A549) and a normal epithelial cell line (Vero) through the MTT method. The ethanolic extract exhibited notable bioactive properties, as indicated by its high total phenolic content (TPC) of 235.86 ± 1.35 mg GAE/g, total flavonoid content (TFC) of 43.93 ± 1.14 mg QE/g, ferric reducing antioxidant power (FRAP) of 332.04 ± 16.78 µmol FeSO_4.7H₂O/g, and a 2,2-diphenyl-1-picrylhydrazyl (DPPH)^• radical scavenging activity (SC₅₀) of 0.01 ± 0.00 mg/mL. High-performance liquid chromatography (HPLC–PDA) revealed that pinocembrin, chrysin, and caffeic acid phenethyl ester (CAPE) were the predominant compounds. The propolis extract showed antimicrobial activity against 7 of 14 tested microorganisms using the agar well diffusion method. While the extract inhibited quorum sensing activity, it did not exhibit anti-swarming or anti-biofilm effects. Cytotoxicity was observed in Vero and A549 cells at a concentration of 200 µg/mL, and in MDA-MB-231 and AR42J cells at 50 µg/mL. Moreover, the propolis extract displayed antiviral activity against HSV-1 at a concentration of 100 µg/mL. These findings underscore the broad-spectrum biological activity of Turkish propolis, reinforcing its potential as a nutraceutical agent with antioxidant, antimicrobial, antiviral, and anticancer properties.

Graphical Abstract