Compiled by Initiative Team Member John Collier, PhD
Ultraviolet (UV) radiation is part of the spectrum emitted by the sun. Whereas UVC rays (wavelengths of 100-280 nm) are absorbed by the atmospheric ozone, most radiation in the UVA range (315-400 nm) and about 10 % of the UVB rays (280-315 nm) reach the Earth’s surface. Both UVA and UVB are of major importance to human health. Small amounts of UV are essential for the production of vitamin D in people, yet overexposure may result in acute and chronic health effects on the skin, eye and immune system. The biggest of these is skin cancer which is the most common cancer in all countries along the equator including America, Africa and Australia (WHO Global Cancer Report 2008 http://www.who.int/uv/en/index.htm l). Less extreme though, UV exposure can increase the aging of skin by breaking down the collagen that keeps our skin young looking.
Mushrooms can produce compounds called exopolysaccharides (EPS) that can help to protect against UV damage by inhibiting the production of enzymes that break down collagen in our skins. This has been shown in human cell lines. UV light also can cause mutations and shiitake and Agaricus blazei have shown an anti-mutagenic effect on eukaryotic cells.
In Vitro Studies (human cell lines)
The photo-protective potential of exoploysaccharides (EPS) from Grifola frondosa HB0071 has been tested in human dermal fibroblasts (HDF) exposed to ultraviolet-A (UVA) light. It was reported that EPS had an inhibitory effect on human interstitial collagenase (matrix metalloproteinase, MMP-1) expression in UVA-irradiated HDF without any significant cytotoxicity. The treatment of UVA-irradiated HDF with EPS resulted in a dose-dependent decrease in the expression level of MMP-1 mRNA. The data suggested that EPS obtained from a mycelial culture of G. frondosa HB0071 may contribute to an inhibitory action in photo-ageing skin by reducing the MMP 1related matrix degradation system (Bae et al., 2005).
The anti-mutagenic effect of the mushrooms Lentinula edodes and Agaricus blazei have been studied on conidia of Aspergillus nidulans when exposed to short wave ultraviolet (UV) light. The data demonstrated a radio-protective and anti-mutagenic effect of L. edodes and A. blazei mushrooms on eukaryotic cells when exposed to UV radiation (Souza-Paccola et al., 2004).