Antioxidant activity of symbiotic organisms known as lichens is an intriguing field
of research because of its strong contribution to their ability to withstand extremes
of physical and biological stress (e.g., desiccation, temperature, UV radiation, and
microbial infection). We present a comparative study on the antioxidant activities
of 76 Icelandic and 41 Hawaiian lichen samples assessed employing the DPPH and FRAP
based antioxidant assays. Utilizing this unprecedented sample size, we show that while
highest individual sample activity is present in the Icelandic dataset, the overall
antioxidant activity is higher for lichens found in Hawaii. Furthermore, we report
that lichens from the genus Peltigera that have been described as strong antioxidant producers in studies on Chinese, Russian
and Turkish lichens, also show high antioxidant activities in both Icelandic and Hawaiian
lichen samples. Furthermore, we show that opportunistic sampling of lichens in both
Iceland and Hawaii will yield high numbers of lichen species that exclusively include
green algae as photobiont.
