Serotonin transporter and receptor ligands with antidepressant activity as neuroprotective and proapoptotic agents.

Serotonin exhibits multiple non-neural functions involved in essential hypertension, early embryogenesis, follicle maturation and behaviour. The growth stimulatory effects of the neurotransmitter have been described for a variety of cell types. 5-HT was found to induce migration of the human prostate cancer cell lines - PC-3 and Du145 - and several 5-HT1A antagonists and serotonin reuptake inhibitors were reported to inhibit the growth of different tumour cell lines in vitro. Recent studies suggest that neurogenesis is involved in the action of antidepressants and an involvement of antidepressants in adult hippocampal neurogenesis has been demonstrated. Antidepressants also exhibit neuroprotective activity, which could be connected to their antidepressant activity. However, it has been reported that certain antidepressants may induce apoptosis in some cancer cell lines. In the present paper the neuroprotective and proapoptotic activities of serotonergic antidepressants (SSRIs and TCAs), as well as 5-HT1A receptor ligands are summarized and discussed based on biochemical transduction pathways associated with these activities.