evaluation of the antidepressant-like effects of acute and sub-acute administration of crocin and crocetin in mice

objective: the present study was designed to investigate the putative antidepressant effects of crocin and crocetin, two major active ingredients of crocus sativus l. (saffron) using mice in two different regimens of acute and sub-acute administration. material and methods: in acute treatment, antidepressant-like activities of crocin and crocetin (10, 20 and 40 mg/kg, i.p.) were evaluated using forced swim test (fst). in sub-acute study (21 times with 24-h intervals), antidepressant-like effects of oral administration of drugs were examined using fst and tail suspension test (tst). locomotor activity and motor coordination were studied using open field and rotarod tests, respectively. results: acute treatment with crocin (40 mg/kg) and crocetin (20 and 40 mg/kg) produced antidepressant-like effect in fst without affecting the baseline locomotion in mice. sub-acute oral administration of crocin significantly decreased immobility time only at the highest dose (100 mg/kg). crocetin (12.5, 25 and 50 mg/kg) was able to decrease immobility time in fst and tst. locomotor activity and coordination of mice were not affected by crocin or crocetin. conclusion: since higher doses of crocin was required to show antidepressant effects, more efficacy of crocetin may be concluded. this observation provides further support for metabolism of crocin to crocetin following oral administration.