The basidiomycetous mushroom Phellinus igniarius (L.) Quel. has been used as
traditional medicine in various Asian countries for many years. Although many reports exist on its anti-oxidative and anti-inflammatory activities and
therapeutic effects against various diseases, our current knowledge of its effect on
stroke is very limited.
Stroke is a
neurodegenerative disorder in which oxidative stress is a key hallmark. Following the 2005 discovery by Igarashi's group that
acrolein produced from
polyamines in vivo is a major cause of cell damage by oxidative stress, we now describe the effects of anti-oxidative extracts from P. igniarius on symptoms of experimentally induced
stroke in mice. The toxicity of
acrolein was compared with that of
hydrogen peroxide in a mouse mammary
carcinoma cell line (FM3A). We found that the complete inhibition of FM3A cell growth by 5 μM
acrolein could be prevented by crude
ethanol extract of P. igniarius at 0.5 μg/ml. Seven
polyphenol compounds named
3,4-dihydroxybenzaldehyde, 4-(3,4-dihydroxyphenyl-3-buten-2one, inonoblin C,
phelligridin D, inoscavin C, phelligridin C and interfungin B were identified from this ethanolic extract by LCMS and 1H NMR.
Polyphenol-containing extracts of P. igniarius were then used to prevent
acrolein toxicity in a mouse
neuroblastoma (Neuro-2a) cell line. The results suggested that Neuro-2a cells were protected from
acrolein toxicity at 2 and 5 μM by this
polyphenol extract at 0.5 and 2 μg/ml, respectively. Furthermore, in mice with experimentally induced
stroke, intraperitoneal treatment with P. igniarius
polyphenol extract at 20 μg/kg caused a reduction of the
infarction volume by 62.2% compared to untreated mice. These observations suggest that the
polyphenol extract of P. igniarius could serve to prevent
ischemic stroke.