Journal
JOURNAL OF ETHNOPHARMACOLOGY
Volume 76, Issue 1, Pages 49-57Publisher
ELSEVIER IRELAND LTD
DOI: 10.1016/S0378-8741(01)00210-0
Keywords
dementia; hypericum; adrenergic; serotonergic; mice
Ask authors/readers for more resources
Depression, among other non-cognitive symptoms, is common in patients with dementia. The effect of Hypericum perforatum (St. John's Wort) extract, with well-documented antidepressant activity, was tested on memory retrieval 24 h after training on a one-trial passive avoidance task in mice. Acute administration of Hypericum extract (4.0. 8.0, 12.0, and 25.0 mg/kg i.p.) before retrieval testing increased the step-down latency during the test session. The same doses of Hypericum extract, on the other hand, failed to reverse scopolamine-induced amnesia of a two-trial passive avoidance task. The involvement of serotonergic, adrenergic, and dopaminergic mechanisms in the facilitatory effect of Hypericum extract on retrieval memory was investigated. Pretreatment of the animals with serotonergic 5-HT1A receptor antagonist (-)-pindolol (0.3, 1.0, and 3.0 mg/kg). serotonergic 5-HT2A receptor blocker spiperone (0.01, 0.03, and 0.1 mg/kg), alpha adrenoceptor antagonist phentolamine (1, 5, and 10 mg/kg), beta receptor antagonist propranolol (5, 7.5, and 10 mg/kg), dopaminergic D1 receptor antagonist SCH 23390 (0.01, 0.05. and 0.1 mg/kg), and dopaminergic D2 receptor antagonist sulpiride (5, 7.5 and 10 mg/kg) revealed the involvement of adrenergic and serotonergic 5-HT1A receptors in the facilitatory effect of Hypericum extract on retrieval memory. It is concluded that Hypericum extract may be a better alternative for treatment of depression commonly associated with dementia than other antidepressants known to have anticholinergic side effects causing delirium. sedation and even exacerbating already existing impaired cognition. In dementias of old age, Hypericum perforatum would, therefore, serve as one medication targeting both depression and amnesia with lower potential side effects. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available