New Study: Cranberries Pack a Punch to Bacteria Linked to Cystic Fibrosis

By Michele McDonald

Monique Van Hoek

Monique Van Hoek

Best known for its tart juice and cheery red holiday sauce, the cranberry shows promise in preventing debilitating bacteria from taking hold in the lungs of people with cystic fibrosis, George Mason University researchers have discovered.

George Mason researchers are seeking out naturally based remedies to beat back antibiotic-resistant bacteria—and finding success.

“Sometimes problems have already been solved in the natural world,” says researcher and study co-author Monique Van Hoek.

Cranberry juice is widely used as a home remedy for inhibiting bacteria that cause urinary tract infections.

“We saw that and thought ‘Will it have any effect on other bacteria?’” Van Hoek says.

Stephanie Barksdale

Stephanie Barksdale

It does, specifically against a bacterial pathogen called Pseudomonas aeruginosa, an opportunistic bacterium that lodges in the lungs of patients with the lung disease cystic fibrosis, says study co-author Stephanie Barksdale, a Mason graduate student.

Bacteria produce sticky biofilms to grab hold of cell tissue and set up shop in the body. Once there, they’re difficult to send packing and they can be more resistant to antibiotics. A compound in cranberries called A-type proanthocyanidins disrupts the bacteria’s ability to make biofilm. It also appears to give antibiotics a better shot at killing the bacteria.

“We found there was synergy between the antibiotic and the cranberry compound in killing the Pseudomonas bacteria,” says Barksdale, who grew up in Sterling and graduated from Mason in 2012 with a biology degree.

While the finding is compelling, the researchers caution against relying on cranberries as a medicinal remedy.

“We’re not saying that cranberries are going to be a cure for Pseudomonas infections in cystic fibrosis patients,” says Van Hoek, who is also professor in Mason’s School of Systems Biology and the National Center for Biodefense and Infectious Diseases.

With urinary tract infections, cranberry juice is drunk and takes a direct route to the bladder. Researchers still need to determine if it is possible to deliver the cranberry compound into the lungs.

“We’re mainly just trying to get this new idea out there, that a natural product like cranberry extract could be useful against these other bacteria,” Van Hoek says.

Mason researchers used another Mason specialty—proteomics––to find out if the bacteria’s proteins showed any change after being treated with cranberry extract. Working with researcher Weidong Zhou from Mason’s Center for Applied Proteomics and Molecular Medicine, they discovered that cranberry extract decreased the number of proteins containing iron, many of which are important for the production of energy—a key component to bacteria survival.

The research also gave Barksdale the opportunity to mentor undergrads as part of her master’s degree.

“Mentoring is my favorite thing to do,” she says.

She mentored co-author and then-undergrad Robert Ulrey, who is now working on his master’s degree at the University of Southern California after graduating from Mason with his bachelor’s degree in biology.

Barksdale understands how important mentors can be in guiding a career path. She met Van Hoek as a biology undergrad.

“You should come and work in my lab,” Van Hoek says she told her protégé.

While working with Van Hoek, Barksdale has found she enjoys the challenge of learning new techniques and working in a lab. Now she wants to finish her degree and work in the biodefense industry.

The team’s cranberry paper was recently published in the journal BMC Complementary and Alternative Medicine.