November 30, 2012. The November, 2012 issue of the journal Investigative Ophthalmology & Visual Science reported that carnosic acid, a compound occurring in the herb rosemary, helped protect the eyes' retina from degeneration and hydrogen peroxide-induced toxicity.
Acting on previous findings of a protective effect for carnosic acid against free-radical damage in the brain, Stuart A. Lipton, MD, PhD, who is the director of Sanford-Burnham Medical Research Institute's Del E. Webb Neuroscience, Aging, and Stem Cell Research Center, and his colleagues tested the effect of carnosic acid on retina-derived cell lines treated with hydrogen peroxide, which promotes oxidative stress, a factor believed to be involved in the progression of age-related macular degeneration and retinitis pigmentosa. The team found that carnosic acid induced the production of antioxidant enzymes and lowered free radicals and peroxides.
In a study involving dark-adapted rats, those that received carnosic acid prior to white light exposure experienced less retinal damage. Increases in outer retinal nuclear layer thickness measured in carnosic acid-treated animals indicated improved retinal photoreceptor protection. Treated rats also exhibited improved electroretinogram activity, a measure of photoreceptor function. "These findings suggest that carnosic acid may potentially have clinical application to diseases affecting the outer retina, including age-related macular degeneration and retinitis pigmentosa, in which oxidative stress is thought to contribute to disease progression," the authors conclude.
Dr Lipton revealed that "We're now developing improved derivatives of carnosic acid and related compounds to protect the retina and other brain areas from a number of degenerative conditions, including age-related macular degeneration and various forms of dementia."
