Abstract
Antidepressants may be effective treatment for smoking cessation and new evidence on relationship between smoking and depression is emerging. Extracts of the plant Hypericum perforatum possess antidepressant activity in humans and reduce nicotine withdrawal signs in mice. Both nicotine and H. perforatum administration elicit changes in serotonin (5-HT) formation in the brain. On this basis, we investigated the possible involvement of 5-HT in the beneficial effects of H. perforatum on nicotine withdrawal signs. With the aim to induce nicotine dependence, nicotine (2 mg/kg, four intraperitoneal injections daily) was administered for 14 days to mice (NM). Saline (controls, M) or H. perforatum extract (Ph 50, 500 mg/kg) were orally administered immediately after the last nicotine injection for 30 days after nicotine withdrawal. Another group of animals treated with nicotine (14 days) and successively with H. perforatum extract was intraperitoneally co-administered with selective 5-HT receptorial antagonist WAY 100635 (WAY) (1 mg/kg). All animals were evaluated for locomotor activity and abstinence signs, 24 after nicotine withdrawal. Brain 5-HT metabolism was evaluated in the cortex of mice sacrificed 30 days after nicotine withdrawal through evaluation of 5-HT, 5-hydroxyindoleacetic acid (5-HIAA) and 5-HIAA/5-HT ratio. After nicotine withdrawal measurement of 5-HT metabolism in the cortex showed a reduction of 5-HT content while animals treated only with Hypericum extract showed a significant reduction of total abstinence score compared to controls. WAY inhibited the reduction of total abstinence score induced by H. perforatum. Moreover, 5-HT1A expression has been evaluated 30 days after nicotine withdrawal. Our results, show a significant increase of cortical 5-HT content in NM treated with H. perforatum, with a concomitant significant increase of 5-HT1A receptor. So, it is possible to suggest an involvement of 5-HT in beneficial effects of H. perforatum on suffering produced by nicotine withdrawal in dependent mice.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
