Effects of majonoside-R2 on pentobarbital sleep and gastric lesion in psychologically stressed mice

• Published in: Pharmacology, biochemistry and behavior Vol. 53; no. 4; pp. 957 - 963
• Main Authors: Huong, Nguyen Thi Thu, Matsumoto, Kinzo, Yamasaki, Kazuo, Duc, Nguyen Minh, Nham, Nguyen Thoi, Watanabe, Hiroshi
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-04-1996; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Diazepam - pharmacology; Gastric lesion; Ginsenosides; Hypnotics and Sedatives - pharmacology; Majonoside-R2; Male; Medical sciences; Mice; Mice, Inbred Strains; Naloxone - pharmacology; Narcotic Antagonists - pharmacology; Neuropharmacology; Panax - chemistry; Pentobarbital - pharmacology; Pentobarbital-induced sleep; Pharmacology. Drug treatments; Plant Extracts - pharmacology; Plants, Medicinal; Psycholeptics: tranquillizer, neuroleptic; Psychological stress; Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Saponins - pharmacology; Sleep - drug effects; Stomach Ulcer - etiology; Stress, Psychological - complications; Stress, Psychological - psychology; Time Factors; Vietnamese ginseng extract; Vietnamese ginseng total saponin; Psychological stress; Majonoside-R2; Vietnamese ginseng total saponin; Pentobarbital-induced sleep; Gastric lesion; Vietnamese ginseng extract; Intraperitoneal administration; Psychotropic; Anxiety disorder; Extract; Benzodiazepine receptor; Panax ginseng; Medicinal plant; Saponin; Prevention; Dicotyledones; Angiospermae; Mechanism of action; Araliaceae; Gastric disease; Rodentia; Oral administration; Stress; Vertebrata; Chemotherapy; Mammalia; Treatment; Tranquillizer; Mouse; Animal; Plant origin; Digestive diseases; Spermatophyta
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/0091-3057(95)02147-7

The effects of Vietnamese ginseng (VG) and its major constituent majonoside-R2 on pentobarbital-induced sleep and gastric lesion in psychologically stressed mice were examined. Psychological stress exposure for 30 min significantly decreased the duration of pentobarbital (50 mg/kg, IP)-induced sleep in mice. VG extract (50 mg/kg, PO), VG saponin (25 mg/kg, PO), and majonoside-R2 (3.1–12.5 mg/kg, PO and IP) had no effect on pentobarbital sleep in unstressed control mice, but these drugs significantly recovered pentobarbital sleep decreased by psychological stress to the level of unstressed control animals. On the other hand,
Panax ginseng (PG) extract (50–100 mg/kg, PO) failed to affect pentobarbital sleep in psychologically stressed mice. The effect of majonoside-R2 on psychological stress-induced decrease in the hypnotic activity of pentobarbital was significantly blocked by flumazenil (1 mg/kg, IV), a selective benzodiazepine antagonist. Diazepam (0.1 mg/kg, IP) significantly prolonged pentobarbital sleep in unstressed and psychologically stressed groups, and the effect of diazepam was significantly attenuated by the same dose of flumazenil. Naloxone (0.5–5 mg/kg, IP), an opioid antagonist, had no effect on pentobarbital sleep in unstressed or psychologically stressed animals. Psychological stress exposure for 16 h caused gastric lesion in mice. VG extract (25–50 mg/kg, PO) and majonoside-R2 (6.2–12.5 mg/kg, PO), as well as diazepam and naloxone, produced the protective action on gastric lesion in psychologically stressed mice. These results suggest that VG and its major constituent majonoside-R2 have the protective effects on the psychological stress-induced pathophysiological changes and that benzodiazepine receptors are partly implicated in the effects of majonoside-R2.