Διερεύνηση της δράσης των παραγώγων του Crocus sativus L. επί του κεντρικού νευρικού συστήματος στον επίμυ

Abstract

Crocus sativus L. is a rare plant, known since antiquity, which is cultivated in countries ofthe Mediterranean sea and of central Asia. The dried red stigmas of its flowers consist the drugand contain significant amounts of water-soluble carotenoids, known as crocins. Crocins arecrocetin glycosides and are considered responsible for the plant’s extensive therapeuticproperties.Various studies have demonstrated crocins’ chemopreventive, antitumoral, antioxidant,anti-inflammatory and cardioprotective properties. Regarding the central nervous system there isevidence that crocins act beneficially in learning and memory processes, exhibit analgesic effectsand alleviate symptoms in experimental models of epilepsy. Furthermore clinical studies haverevealed their antidepressant effect. Since it remains unknown if this drug affects otherpathophysiological routes of the central nervous system, the aim of the present study was toinvestigate the possible beneficial action of crocins on experimental models of anxiety,obsessive-compulsive disorder and schizophrenia.In order to examine the effect of crocins on anxiety we selected the light/dark test, anexperimental model which evaluates the anxiolytic action of compounds in rodents and is basedon their innate aversion to brightly illuminated areas. Results showed that crocins exhibit aremarkable anxiolytic effect, similar to that of diazepam.For the evaluation of crocins’ effects on obsessive-compulsive disorder we selectedm–chlorophenylpiperazine (m-CPP), a serotoninergic 5–ΗΣ2c agonist, which is known to induceexcessive self-grooming in rats. Excessive self- grooming is considered as a model ofobsessive-compulsive behavior in rodents. The analysis of the results demonstrated that crocinsantagonized the action of mCPP and reduced the time spent by rats in self-grooming.Finally in order to examine crocins’ efficacy in experimental models of schizophrenia weused ketamine, a non-competitive NMDA antagonist, which in subanesthetic dosage produces apsychotomimetic syndrome, characterized by hyperlocomomotion, ataxia, stereotypies, socialwithdrawal and working memory deficits. To determine crocins’ action against the whole spectrumof symptoms we performed three behavioral techniques: an open field test for the motordisorders, which are considered analogs of positive symptoms of schizophrenia, the socialinteraction test for the evaluation of social withdrawal, which serves as a model for the negativesymptoms and the novel object recognition task for the memory deficits, which mimic thecognitive deficits of patients with schizophrenia. Administration of crocins alleviated the motordisorders and antagonized the social withdrawal and memory deficits, caused by ketamine