Effect of boiling and extraction methods using water or 80 % ethanol on the physiological activities of the inner shell of chestnut (Castanea crenata)

Chestnut inner shells, generated as waste during chestnut processing, were extracted either raw (RC) or after boiling (BC) using four different extraction methods to determine the effects of those on physiological activities. The hot-water extract of RC showed the highest radical scavenging activities among all the extracts, the autoclave extract of RC showed the highest SOD-like activity and the hot-water extract of BC showed the highest lipase and α-glucosidase inhibitory activities. The lowest NO production in the macrophages treated with the stirring extract of BC and hot water extract of RC most significantly reduced the mRNA expression of inducible NO synthase and pro-inflammatory cytokines, IL-6 and TNF-α. These results implied that the application of boiling and a certain extraction method enhances specific target activities and confirmed the potential of chestnut inner shell as a useful material with health benefits and economic value.