Antiviral Activity and Mode of Action of Propolis Extracts and Selected Compounds

Abstract

Aqueous and ethanol extracts of propolis were analysed phytochemically and examined for their antiviral activity in vitro. Different polyphenols, flavonoids and phenylcarboxylic acids were identified as major constituents. The antiviral effect of propolis extracts and selected constituents, e.g. caffeic acid (1), p-coumaric acid (2), benzoic acid (3), galangin (4), pinocembrin (5) and chrysin (6) against herpes simplex virus type 1 (HSV-1) was analysed in cell culture. The 50% inhibitory concentration (IC(50)) of aqueous and ethanol propolis extracts for HSV-1 plaque formation was determined at 0.0004% and 0.000035%, respectively. Both propolis extracts exhibited high levels of antiviral activity against HSV-1 in viral suspension tests, plaque formation was significantly reduced by >98%. In order to determine the mode of antiviral action of propolis, the extracts were added at different times during the viral infection cycle. Both propolis extracts exhibited high anti-HSV-1 activity when the viruses were pretreated with these drugs prior to infection. Among the analysed compounds, only galangin and chrysin displayed some antiviral activity. However, the extracts containing many different components exhibited significantly higher antiherpetic effects as well as higher selectivity indices than single isolated constituents. Propolis extracts might be suitable for topical application against herpes infection.

Hepatoprotective effects and HSV-1 activity of the hydroethanolic extract ofCecropia glaziovii(embaúba-vermelha) against acyclovir-resistant strain

“…Chlorogenic acid and its related compounds are abundant plant polyphenols that have anti HSV-1 activity (Chiang et al, 2002;Wang et al, 2009;Nolkemper et al, 2010). In the same way, the anti-HSV activity of naturally occurring flavonoids has also been described (Lyu et al, 2005;Schnitzler et al, 2010). Therefore, our findings suggest that at least part of the anti HSV-1 effects of the RCE40 extract might be attributable to its phenolic composition.…”

Seasonal benefits of a natural propolis envelope to honey bee immunity and colony health

“…The propolis treatment did not appear to have antiviral activity (except for the marginal activity against BQCV only, in May 2014), although it has been reported that some viruses are more susceptible to propolis than others in vitro (Amoros et al, 1992;Kujumgiev et al, 1999). The antiviral activity of propolis against human viruses is well documented in human cell culture (Amoros et al, 1992;Gekker et al, 2005;Kujumgiev et al, 1999;Schnitzler et al, 2010). Viruses are obligate intracellular parasites and they must enter host cells in order to live and reproduce.…”

Induction of apoptosis by 7-piperazinethylchrysin in HCT-116 human colon cancer cells

“…Chrysin (5,7-dihydroxyflavone) is a natural flavonoid presented in many plant extracts, including blue passion flower (Passiflora caerulea), honey and propolis (10). A number of studies have shown that chrysin has multiple biological activities, such as antiinflammation, antioxidation and anticancer effects (11)(12)(13). Chrysin has been reported to induce apoptosis in a panel of cancer cell lines, including HeLa cervical cancer cells, U937, HL-60 and L1210 leukemia cells (14).…”