title: Yokukansan inhibits social isolation-induced aggression and methamphetamine-induced hyperlocomotion in rodents.
abstract: Behavioral and psychological symptoms of dementia (BPSD) are commonly seen in patients with Alzheimer's disease (AD) and other forms of senile dementia. BPSD have a serious impact on the quality of life of dementia patients, as well as on that of their caregivers. However, effective drug therapy for BPSD has not been established. Recently, the traditional Japanese medicine Yokukansan (YKS, Yi-gan san in Chinese) has been reported to improve BPSD, such as aggression, agitation, irritability, and hallucinations, in a randomized, single-blind, placebo-controlled study. However, the psychopharmacologic effects of YKS remain unexplored. In the present study, we investigated the effects of YKS on social isolation-induced aggressive behavior and methamphetamine- or MK-801-induced hyperlocomotion in rodents. Social isolation markedly induced aggressive behavior in male Wistar rats. Quetiapine at a dose of 10 mg/kg (per os (p.o.)) significantly inhibited this social isolation-induced aggressive behavior. YKS (100, 300 mg/kg, p.o.) also significantly inhibited the aggressive behavior. Moreover, risperidone (0.1 mg/kg, p.o.) significantly inhibited methamphetamine- or MK-801-induced hyperlocomotion in mice. YKS (300 mg/kg, p.o.) inhibited methamphetamine-induced hyperlocomotion, while YKS at the same dose had no effect on MK-801-induced hyperlocomotion. These findings suggest that YKS may be useful for the treatment of aggression and agitation, and that the psychopharmacologic effects of YKS might be mediated, in part, by inhibiting the activity of the dopaminergic system.
authors.affiliation: Department of Psychiatry, Fukuoka University School of Medicine, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Uchida
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Egashira
authors.forename: Katsunori
authors.initials: K
authors.lastname: Iwasaki
authors.forename: Ayumi
authors.initials: A
authors.lastname: Ishibashi
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tashiro
authors.forename: Ai
authors.initials: A
authors.lastname: Nogami
authors.forename: Naomi
authors.initials: N
authors.lastname: Manome
authors.forename: Moe
authors.initials: M
authors.lastname: Abe
authors.forename: Kotaro
authors.initials: K
authors.lastname: Takasaki
authors.forename: Kenichi
authors.initials: K
authors.lastname: Mishima
authors.forename: Jiro
authors.initials: J
authors.lastname: Takata
authors.forename: Ryozo
authors.initials: R
authors.lastname: Oishi
authors.forename: Ryoji
authors.initials: R
authors.lastname: Nishimura
authors.forename: Michihiro
authors.initials: M
authors.lastname: Fujiwara
mesh_terms: D000374:Aggression / Q000187:drug effects*; D000818:Animals; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000627:therapeutic use; D006948:Hyperkinesis / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D008694:Methamphetamine; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D012934:Social Isolation; D013315:Stress, Psychological / Q000188:drug therapy* / Q000523:psychology
chemical_list: D004365:Drugs, Chinese Herbal; C524644:Yi-Gan San; D008694:Methamphetamine