Changes in Drosophila melanogaster Sleep-Wake Behavior Due to Lotus (Nelumbo nucifera) Seed and Hwang Jeong (Polygonatum sibiricum) Extracts

We evaluated the sleep enhancement activity of the medicinal herbs valerian (Valeriana officinalis), jujube (Ziziphus jujube), lotus seed (Nelumbo nucifera), Gastrodia elata, Polygonatum sibiricum, and baekbokryung (Poria cocos), which can relieve insomnia in a Drosophila model. Locomotor activity was measured in the Drosophila model to evaluate the sleep activity of Korean medicinal herbs traditionally used as sleep aids. The group treated with lotus seed extract showed less nocturnal activity. Treatment with 10 or 20 mg/mL of P. sibiricum significantly reduced nocturnal activity compared to the control group (P<0.05). The activity and sleep bouts of fruit flies were significantly decreased by a high-dose treatment (10 mg/mL) of lotus or P. sibiricum extracts at night. Caffeine-treated Drosophila showed increased nocturnal activity and decreased total sleep time (P<0.05). Flies receiving the 10 mg-doses of lotus seed or P. sibiricum extract showed significantly different nocturnal locomotor activity and total sleep time compared to caffeine-treated Drosophila. Lotus seed and P. sibiricum extracts are attractive and valuable sleep-potentiating nutraceuticals.