Wheat Alkylresorcinols Induce Non-Rapid Eye Movement Sleep by Reducing Core Body Temperature in Mice

Wheat alkylresorcinols (ARs) possess several biological activities that include antioxidative and neuroprotective properties. The effects of ARs on sleep regulation remain unknown. In this study, we hypothesized that ARs may contribute to the sleep-improving effects of whole grains. Male C3H/HeN mice were individually housed under a 12-h light-12-h dark cycle and intragastrically injected with vehicle or ARs at the time of lights off (activity onset). We then continuously monitored electrical activity in the brain using polygraphic electroencephalography, spontaneous locomotor activity, and subcutaneous and core body temperatures in the mice. An initial decrease in core body temperature was followed by decreased subcutaneous body temperature, locomotor activity, wakefulness, and increased non-rapid eye movement sleep for several hours in the mice injected with ARs. These findings suggested that ARs improve sleep onset by reducing core body temperature. Further studies are required to elucidate the molecular mechanism of the effects of ARs on body temperature and sleep regulation.