title: Suppressive effects of vietnamese ginseng saponin and its major component majonoside-R2 on psychological stress-induced enhancement of lipid peroxidation in the mouse brain.
abstract: We investigated the in vivo effects of Vietnamese ginseng saponin (VG saponin) and its major component majonoside-R2 (MR2) on psychological stress-induced enhancement of lipid peroxidation in the mouse brain. Psychological stress exposure using a communication box system for 4 h significantly increased the content of thiobarbituric acid reactive substance (TBARS), an index of lipid peroxidation activity, in the brain. Pretreatment with VG saponin (15-25 mg/kg, PO) and MR2 (1-10 mg/kg, IP) significantly attenuated the psychological stress-induced increase in TBARS content in the brain. The aglycone of MR2 (MR2-aglycone: 1.2 mg/kg, IP), at the equivalent dose of MR2 (i.e., 3 mg/kg, IP), also produced the suppressive effect on the increase in the TBARS content. The in vivo suppressive effect of MR2 was dose dependently attenuated by flumazenil (3 and 10 mg/kg, IP), a benzodiazepine receptor antagonist, and pregnenolone sulfate (10 mg/kg, IP), a neurosteroidal negative allosteric modulator of GABA(A) receptors. These findings suggest that VG saponin and its major component MR2 have preventive effects on the psychological stress-induced brain cell membrane damage, and that the effect of MR2 is partly due to enhancement of GABA(A)-ergic systems in the brain.
authors.affiliation: Department of Pharmacology, Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, 930-0194, Toyama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yobimoto
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: N T
authors.initials: NT
authors.lastname: Huong
authors.forename: R
authors.initials: R
authors.lastname: Kasai
authors.forename: K
authors.initials: K
authors.lastname: Yamasaki
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D036145:Ginsenosides; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D005894:Panax / Q000737:chemistry*; D010946:Plants, Medicinal; D012503:Saponins / Q000494:pharmacology* / Q000627:therapeutic use; D013315:Stress, Psychological / Q000188:drug therapy / Q000378:metabolism*; D013858:Thiobarbiturates / Q000378:metabolism; D014744:Vietnam
chemical_list: D016588:Anticarcinogenic Agents; D036145:Ginsenosides; D012503:Saponins; D013858:Thiobarbiturates; C098043:majonoside R2