Magic of Cranberry Juice

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Compounds In Cranberry Juice Show Promise As Alternatives To Antibiotics For

Treating A Host Of Human IllnessesMain Category: Nutrition/Agriculture News

http://www.medicalnewstoday.com/medicalnews.php?newsid=51584 & nfid=29520

 

Compounds in cranberry juice have the ability to change E. coli bacteria, a

class of microorganisms responsible for a host of human illnesses (everything

from kidney infections to gastroenteritis to tooth decay), in ways that render

them unable to initiate an infection. The results of this new research by

scientists at Worcester Polytechnic Institute (WPI) suggest that the cranberry

may provide an alternative to antibiotics, particularly for combating E. coli

bacteria that have become resistant to conventional treatment.

 

The new findings, which will be presented on Sunday, Sept. 10, at the annual

meeting of the American Chemical Society in San Francisco, for the first time

begin to paint a detailed picture of the biochemical mechanisms that may

underlie a number of beneficial health effects of cranberry juice that have been

reported in other studies over the years.

 

Many of those studies have focused on the ability of cranberry juice to prevent

urinary tract infections (UTIs), which each year affect eight million people --

mostly women, the elderly, and infants -- resulting in $1.6 billion in health

care costs. Until now, scientists have not understood exactly how cranberry

juice prevents UTIs and other bacterial infections, though they have suspected

that compounds in the juice somehow prevent bacteria from adhering to the lining

of the urinary tract. The new findings reveal how the compounds interfere with

adhesion at the molecular level.

 

The new results will be incorporated in two presentations during a session that

runs from 8:30 to 11:40 a.m. PDT in the Windsor Room of the Sir Francis Drake

Hotel.

 

The research, by Terri Camesano, associate professor of chemical engineering at

WPI, and graduate students Yatao Liu and Paola Pinzon-Arango, and funded, in

part, by the National Science Foundation, shows that a group of tannins (called

proanthocyanidins) found primarily in cranberries affect E. coli in three

devastating ways, all of which prevent the bacteria from adhering to cells in

the body, a necessary first step in all infections:

 

-- They change the shape of the bacteria from rods to spheres.

 

-- They alter their cell membranes.

 

-- They make it difficult for bacteria to make contact with cells, or from

latching on to them should they get close enough.

 

For most of these effects, the impact on bacteria was stronger the higher the

concentration of either cranberry juice or the tannins, suggesting that whole

cranberry products and juice that has not been highly diluted may have the

greatest health effects.

 

The new results build on previously published work, in which Camesano and her

team showed that cranberry juice causes tiny tendrils (known as fimbriae) on the

surface of the type of E. coli bacteria responsible for the most serious types

of UTIs to become compressed. Since the fimbriae make it possible for the

bacteria to bind tightly to the lining of the urinary tract, the change in shape

greatly reduces the ability of the bacteria to stay put long enough to initiate

an infection.

 

More recently, Camesano and Liu have shown that chemical changes caused by

cranberry juice also create an energy barrier that keeps the bacteria from

getting close to the urinary tract lining in the first place.

 

New work by Camesano and Pinzon-Arango shows that cranberry juice can transform

E. coli bacteria in even more radical ways. The researchers grew E. coli over

extended periods in solutions containing various concentrations of either

cranberry juice or tannins. Over time, the normally rod-shaped bacteria became

spherical -- a transformation that has never before been observed in E. coli.

 

Remarkably, the E. coli bacteria, all of which fall into a class called

gram-negative bacteria, began behaving like gram-positive bacteria -- another

never-before-seen phenomenon. Since gram-negative and gram-positive bacteria

differ primarily in the structure of their cell membranes, the results suggest

that the tannins in cranberry juice can alter the membranes of E. coli.

 

A final, more preliminary result that will be presented at the ACS meeting

suggests that E. coli bacteria exposed to cranberry juice appear to lose the

ability to secrete indole, a molecule involved in a form of bacterial

communication called quorum sensing. E. coli use quorum sensing to determine

when there are enough bacteria present at a certain location to initiate a

successful infection.

 

" We are beginning to get a picture of cranberry juice and, in particular, the

tannins found in cranberries as, potentially potent antibacterial agents, "

Camesano says. " These results are surprising and intriguing, particularly given

the increasing concern about the growing resistance of certain disease-causing

bacteria to antibiotics. "

 

About Worcester Polytechnic Institute

 

Founded in 1865 in Worcester, Mass., WPI was one of the nation's first

engineering and technology universities. WPI's 18 academic departments offer

more than 50 undergraduate and graduate degree programs in science, engineering,

technology, management, the social sciences, and the humanities and arts,

leading to the BA, BS, MS, ME, MBA and PhD. WPI's world-class faculty work with

students in a number of cutting-edge research areas, leading to breakthroughs

and innovations in such fields as biotechnology, fuel cells, nanotechnology, and

information security. Students also have the opportunity to make a difference to

communities and organizations around the world through the university's

innovative Global Perspective Program. There are more than 20 WPI project

centers throughout North America and Central America, Africa, Australia, Asia,

and Europe.

 

Worcester Polytechnic Institute

http://www.wpi.edu

 

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