Abstract
Numerous compounds derived from natural sources such as microbes, plants, and insects have proven to be safe, efficacious, and cost-effective therapeutics for human diseases. This study examined the bioactivities of propolis, a structural sealant and antibacterial/antifungal agent produced by honey bees. Chinese propolis was extracted in methanol or hexane. Propolis significantly reduced the numbers of viable cancer cells when applied as a methanol extract (IC
values in μg/mL for the indicated cell line: MDA-MB-231, 74.12; LoVo, 74.12; HepG2, 77.74; MCF7, 95.10; A549, 114.84) or a hexane extract (MDA-MB-231, 52.11; LoVo, 45.9; HepG2, 52.11; MCF7, 78.01; A549, 67.90). Hexane extract also induced apoptosis of HepG2 cells according to activated caspase-3/7 expression assays (17.6 ± 2.9% at 150 μg/mL and 89.2 ± 1.9% at 300 μg/mL vs 3.4 ± 0.4% in vehicle control), suppressed the growth of
and multiple multidrug-resistant and nonresistant Gram-positive bacteria, and inhibited croton oil-induced skin inflammation when applied as topical treatment. GC-MS identified hexadecanoic acid methyl ester as a major constituent (33.6%). Propolis hexane extract has potential anticancer, antimicrobial, and anti-inflammatory activities.