Data from a cell study indicated that a combination of the extracts was associated with additive benefits for retinal photoreceptor cells exposed UVA, report researchers from Gifu Pharmaceutical University and Wakasa Seikatsu Co. Ltd in Japan.
“We have showed that bilberry and lingonberry protect against UVA-induced retinal photoreceptor cell damage by inhibiting [reactive oxygen species] production and regulating [specific pathways linked to reacting to stress, including UV radiation], which are mediated by anthocyanidin, proanthocyanidin, and trans-resveratrol,” they wrote in the Journal of Agricultural and Food Chemistry.
“Because UVA is one of the known causes of various eye diseases, consumption of bilberry and lingonberry extracts, or their coapplication, may prove useful as a prophylactic measure.”
Eye health supplements represent a $114 million per year business, according to Packaged Facts, with much of the consumer interest and confidence based on data from the National Eye Institute’s Age-Related Eye Disease Study (AREDS).
The original AREDS formula contained vitamin C, vitamin E, beta-carotene, zinc, and a tiny amount of copper. Results of the recently published and highly anticipated AREDS II indicated that lutein and zeaxanthin could enhance the formula, and that beta-carotene could be removed.
While the majority of the eye health science has focused on age-related macular degeneration (AMD), the new study from Japan looked at the potential eye health benefits of lingonberry and bilberry extracts against UVA. While UVB has been linked to issues affecting the cornea and lens of the eye, it does not affect the retina because it is absorbed. UVA, on the other hand, can reach the retina, and have been linked to retinal damage.
The detrimental effects have been linked to the generation of reactive oxygen species (ROS), and since berry extracts have many constituents capable of mopping up ROS, the researchers tested to see if there were beneficial effects.
The researchers treated retinal cells extracts of bilberry and/or lingonberry, and their main constituents, including trans-resveratrol, procyanidin, cyanidin, delphinidin, and malvidin, or placebo. The cells were then exposed to UVA radiation.
Results showed that the bilberry and lingonberry extracts and their main constituents improved cell viability. They also inhibited the generation of ROS, said the researchers.
The extracts were also found to inhibit select biochemical pathways that play crucial roles in the regulation of survival or UVA-induced cell death.
“Finally, we found that simultaneous treatment with both bilberry and lingonberry extracts is more potent than an individual treatment of either against UVA-induced retinal photoreceptor cell damage,” they added.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, doi: 10.1021/jf402772h
“The Protective Effects of Bilberry and Lingonberry Extracts against UV Light-Induced Retinal Photoreceptor Cell Damage in Vitro”
Authors: K. Ogawa, K. Tsuruma, J. Tanaka, M. Kakino, S. Kobayashi, M. Shimazawa, H. Hara