Sydney, Australia—A study at the University of Sydney finds that the elderberry fruit can help fight influenza.

The study, lead by professor Fariba Deghani, Dr. Golnoosh Torabian and Dr. Peter Valtchev and published in the Journal of Functional Foods, shows compounds from elderberries can inhibit the virus’ entry and replication in human cells plus strengthen the immune response, according to a press release.

“What our study has shown is that the common elderberry has a potent direct antiviral effect against the flu virus," Dr. Golnoosh Torabian stated in the release. "It inhibits the early stages of an infection by blocking key viral proteins responsible for both the viral attachment and entry into the host cells.”

According to the release, the study was preformed by taking commercially farmed elderberries that were turned into a juice serum, and applying it to cells before, during and after cells had been infected with the virus.

What surprised the researchers: The elderberries were extremely effective at inhibiting viral propagation at later stages of the influenza cycle when the cells were already infected with the virus, according to the release. Dr. Peter Valtchev said, "This observation was quite surprising and rather significant because blocking the viral cycle at several stages has a higher chance of inhibiting the viral infection."

The researchers also found that the antiviral activity of the elderberry is due to its anthocyanidin compounds, which are the phytonutrients that give the berries their purple coloring.