Researchers Discover How Resveratrol Reduces Airway Inflammation

Compound could be used in new anti-inflammatory agents

A component of red wine and grapes can help control inflammation induced by a bacterial pathogen that is linked to upper respiratory tract inflammatory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and otitis media, according to researchers at Georgia State University.

The study, published online in Scientific Reports, identifies a mechanism that resveratrol––a compound found naturally in some plant foods, such as grapes––uses to alleviate inflammation in airway disease. The results suggest that the compound could be used to develop new anti-inflammatory therapeutic agents, according to the investigators.

“We showed that an important component in red wine and also grapes called resveratrol can suppress inflammation,” said senior author Dr. Jian-Dong Li. “It has been shown that resveratrol can suppress inflammation, but how it regulates inflammation still remains largely unknown. We found that resveratrol suppresses a major bacterial pathogen causing otitis media and COPD by upregulating or increasing the production of a negative regulator called MyD88 short.”

Resveratrol belongs to a group of compounds known as polyphenols, which are thought to act like antioxidants and to protect the body against damage. The compound has long been considered a therapeutic agent for various diseases, including inflammatory diseases. In the new study, resveratrol was effective against inflammation caused by nontypeable Haemophilus influenza (NTHi), a major respiratory pathogen.

An appropriate amount of inflammation in the body is beneficial for defense against bacterial infection, but uncontrolled inflammation leads to inflammatory diseases. Upper respiratory tract inflammatory diseases, such as asthma and COPD, affect more than 500 million people worldwide and are characterized by chronic inflammation that is aggravated by respiratory pathogens, such as NTHi. Asthma results in 250,000 deaths annually and is the leading cause of hospitalizations in children younger than 15 years of age in the United States. COPD is the third leading cause of death in the U.S., and the World Health Organization predicts that it will be the fifth most significant contributor to worldwide disease by 2020. Otitis media is the most common bacterial infection and is also the leading cause of conductive hearing loss in children.

Antibiotics are routinely used to treat NTHi infections, but the increasing numbers of antibiotic-resistant bacterial strains and the limited success of currently available medications used to manage the symptoms of these diseases present an urgent need for the development of nonantibiotic therapeutics.

The new study found that resveratrol reduces the NTHi-induced expression of pro-inflammatory mediators in airway epithelial cells and in the lungs of mice by enhancing MyD88 short, a negative regulator of inflammatory signaling pathways. MyD88 short is considered a “brake pedal protein” because it can tightly control inflammation induced by this respiratory pathogen. According to the authors, it could be a critical target with significant therapeutic potential for suppressing inflammation associated with chronic airway diseases.

The researchers also found that resveratrol has anti-inflammatory effects after NTHi infection, which demonstrated its therapeutic potential.

“The findings help us to shed light on developing new therapeutic strategies by targeting or pharmacologically upregulating MyD88 short production,” Li said. “We could use resveratrol to suppress inflammation or develop resveratrol derivatives that could be pharmacological agents to suppress inflammation using the same strategy.”

Sources: Georgia State University; September 28, 2016; and Scientific Reports; September 28, 2016.