Past studies have found that resveratrol, a polyphenolic compound found abundantly in red wine and grapes, helps reduce inflammation of the arteries. Now, a paper published in the July issue of the American Journal of Pathology, finds the chemical lowers blood-vessel growth in the eye, thereby reducing symptoms associated with the leading causes of blindness.
Researchers at the ophthalmology department at Washington University in St. Louis working with pharmacologists at R.W. Johnson medical school in New Jersey found that resveratrol, when administered in high doses, helps block the formation of new blood vessels, called angiogenesis, in mouse retinas. Angiogenesis in healthy patients is normally balanced, but when vessels grow out of control, the result is symptomatic of several cancers as well as age-related diseases such as diabetic blindness and macular degeneration.
"These disorders encompass the leading causes of all blindness," states the study text, hypothesizing that understanding how to prevent abnormal eye blood-vessel growth is key to developing "novel therapeutic approaches."
The red-wine compound's performance in previous vascular studies made it the perfect candidate for research, said Washington University retina specialist Rajendra Apte, the study’s senior investigator, in a statement. "There were reports on resveratrol’s effects on blood vessels in other parts of the body, but there was no evidence that it had any effects within the eye," he said.
The investigators used a laser to make four incisions on the retinas of mice, thereby stimulating angiogenesis. Some mice received no resveratrol, while two groups received different doses—22.5 milligrams of resveratrol per kilogram of weight or 45 mg/kg. The study authors stress that resveratrol in these amounts is considerably greater than what is found in several bottles of wine.
The scientists found that in the two groups of mice given resveratrol, the abnormal blood vessels began to disappear. The effect was much more marked in the group given the higher dose. After seven days of resveratrol treatment, for example, the volume of abnormal blood vessels was roughly one percent of the amount found in the control group.
The scientists also believe they’ve identified a new pathway in which resveratrol exerts this effect. "We believe the pathway may be involved both in age-related eye disease and in other diseases where angiogenesis plays a destructive role," Apte said, adding that resveratrol may one day be administered orally at high doses as both a preventative and a treatment, most likely in pill form.