Pleurotus eryngii, commonly known as King Oyster mushroom, has been investigated for its antioxidant properties, which are relevant to combating free radical damage. Several in vitro and animal studies have demonstrated that extracts of Pleurotus eryngii possess significant free radical scavenging abilities. The mushroom contains various bioactive compounds, including polysaccharides, phenolic compounds, ergothioneine, and flavonoids, all of which are known to exhibit antioxidant activities. For example, research published in Food Chemistry and other peer-reviewed journals has shown that extracts from Pleurotus eryngii can reduce oxidative stress markers in cell cultures and animal models, indicating a potential to mitigate free radical damage.

Despite these promising findings, most of the evidence comes from laboratory and preclinical animal studies, with a lack of robust human clinical trials specifically examining the mushroom’s efficacy in preventing or treating free radical-related conditions. As such, while there is scientific validation at the preclinical level, clinical evidence remains limited. Therefore, Pleurotus eryngii is considered to have a scientific basis for use as an antioxidant, but the current level of evidence supporting its effectiveness in humans is moderate.