title: Antidepressant and antistress activity of GC-MS characterized lipophilic extracts of Ginkgo biloba leaves.
abstract: Lipophilic extracts of Ginkgo biloba L. leaves were tested for their possible role on rodent models of depression and stress. Lipophilic extracts of Ginkgo leaves (LEG) at (50 and 100 mg/kg, p.o.) exhibited dose dependent, significant antidepressant activity in the behavioral despair test and learned helplessness rodent model of depression. The activities were comparable to that of imipramine (15 mg/kg) and EGb 761 (50 mg/kg). In the cold immobilization stress induced gastric ulcer model of stress, only the LEG showed a significant reduction in the ulcer index. GC-MS characterization of this bioactive extract was found to be rich in a group of 6-alkyl salicylates (6-AS), along with a fatty alcohol, fatty acids and cardanols. The n-heptadecenyl salicylate represented 60% of the 6-AS. Notable was the absence of dihydroxy alkylphenols which are linked to allergic reactions similar to the urushiols present in poison ivy. In commercial products of Ginkgo, these dihydroxy phenols as well as the favorable 6-AS are removed during enrichment of flavonol glycosides and terpenic lactones. The current findings suggest that intact carboxylic acid groups containing 6-AS are the bioactive components of the lipophilic extract of Ginkgo leaves with antidepressant and antistress activities.
authors.affiliation: Kilguss Research Institute, Women and Infants Hospital, Brown University, Providence, RI 02905, USA.
authors.forename: Satyan S
authors.initials: SS
authors.lastname: Kalkunte
authors.forename: Ajay P
authors.initials: AP
authors.lastname: Singh
authors.forename: Fabio C
authors.initials: FC
authors.lastname: Chaves
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Gianfagna
authors.forename: Vishal S
authors.initials: VS
authors.lastname: Pundir
authors.forename: Arun K
authors.initials: AK
authors.lastname: Jaiswal
authors.forename: Nicholi
authors.initials: N
authors.lastname: Vorsa
authors.forename: Surendra
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D020441:Ginkgo biloba / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000627:therapeutic use*; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D013312:Stress, Physiological / Q000188:drug therapy*; D013315:Stress, Psychological / Q000188:drug therapy*
chemical_list: D000928:Antidepressive Agents; D010936:Plant Extracts