Dietary Astaxanthin Protects Against UVA-Induced Skin Damage

Written by Angeline A. De Leon, Staff Writer. Astaxanthin supplementation significantly improved wrinkle formation and skin moisturization in the participating six-week old hairless mice.

As the outermost barrier of the body, the skin, through continuous direct exposure in the natural environment, can accrue significant physical damage over time. Photoaging refers to skin damage caused by chronic exposure to ultraviolet (UV) radiation from the sun. Characteristics include deep wrinkling, dryness, and loss of elasticity ¹. UVA rays, most commonly associated with sunburn and responsible for over 90% of total UV exposure ², have longer wavelengths (320-400 nm) which penetrate deep into the dermis, causing damage to collagen and elastin ³. Chronic exposure to this type of radiation not only diminishes the youthful appearance of skin, but can also cause blemishes, such as age spots on the skin. Research in cosmetology suggests that effects of photoaging may be prevented by accumulating molecules with antioxidant activity in the dermis to buffer against UVA-induced damage. Of particular interest is astaxanthin, a naturally occurring carotenoid pigment found in marine plants and animals which possesses numerous pharmacological effects, including anti-tumor, anti-atherosclerotic, and anti-inflammatory properties ^4,5. Clinical trials indicate that the inflammatory activity of astaxanthin is effective in improving skin conditions such as eczema ⁶ and that astaxanthin can even prevent UVA-induced DNA damage in human skin cells ⁷. In 2017, researchers at Kyoto University in Japan conducted the first in vitro study ⁸ to evaluate the effects of dietary astaxanthin on skin photoaging, examining whether astaxanthin derived from green microalga could protect against UVA-induced skin damage in mice.

Mice were 6-week old female hairless mice who were divided into four groups (n = 5): normal and control groups were fed a standard purified diet for rodents; experimental groups were fed the same diet but with the addition of either 0.01% or 0.1% astaxanthin (extracted from H. pluvialis). Except for the normal group, all mice were exposed to a UV source (strength measured at 365 nm) five times weekly for 70 days. At the end of 70 days, mice were sacrificed and blood and dorsal skin specimens were collected to evaluate wrinkle formation and astaxanthin concentration in the skin and plasma.

Results indicated that following the UVA-irradiation period, transepidermal water loss (TEWL, measure of epidermal permeability barrier function) in both the 0.01% and 0.1% astaxanthin-supplemented groups was significantly lower than that of the control group (p < 0.05 for both). At the end of 70 days, astaxanthin-treated mice, relative to controls, also exhibited significant suppression of parameters associated with wrinkle formation (total groove volume ratio, wrinkle area ratio, wrinkle volume ratio, number of wrinkles) (p < 0.05 for all). Analyses detected the presence of astaxanthin in plasma, observing that plasma concentration of astaxanthin was significantly higher in the 0.1% vs. the 0.01% group (> 5000 mpol/mL vs. < 1000 mpol/mL, p < 0.05). In addition, dietary astaxanthin was found to reach the skin, with detectable concentrations at the dermis (over 500 pmol/cm²) well as epidermis level (about 20 pmol/cm²) for the 0.1% astaxanthin group.

Based on findings, researchers confirm hypotheses regarding dietary astaxanthin’s ability to accumulate not only in the inner layer of skin, but also its surface layer. Evidence shows that by improving features such as wrinkle formation and skin moisturization, astaxanthin provides a protective benefit against skin photoaging caused by UVA radiation. Follow-up studies in human subjects are needed to solidify findings. 

Source: Komatsu T, Sasaki S, Manabe Y, et al. Preventative effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice. PloS ONE. 2017; 12(2): e0171178. DOI: 10.1371/journal.pone.0171178.

© 2017 Komatsu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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Posted May 8, 2018.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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