Crocus sativus L (C. sativus), commonly known as saffron, is a small perennial plant belonging to the family of Iridaceas. This plant is cultivated in many countries including Iran, Afghanistan, Turkey and Spain. The stigmas of Crocus sativus are known to contain carotenoids, α-crocetin and glycoside crocin (responsible for saffron yellow color) and picrocrocin, the aglyconesafranal (responsible for saffron aroma), the antioxidant carotenoids lycopene and zeaxanthin and vitamin B2.
It has been shown that Crocus sativus stigma aqueous extract and its constituents, crocin but not safranal enhanced the sexual activity in male rats. Saffron and its constituentscrocin and safranal are also shown to be potent oxygen radical scavengers.
In traditional medicine, Crocus sativus has been frequently used as an herbal sedative, antispasmodic, aphrodisiac, diaphoretic, expectorant, stimulant, stomachic, anticatarrhal, eupeptic, gingival sedative and emmenagogue. Crocus sativus was experimentally shown to be effective in relieving symptoms of premenstrual syndrome (PMS).
Aqueous (500 mg/kg) and ethanolic extracts of Crocus sativus petals reduced blood pressure in a dose-dependent manner in rats. Administration of the aqueous extract of saffron petals (500 mg/kg) reduced blood pressure from 133.5 ± 3.9 to 117±2.1 mmHg in rats. This reduction was postulated to be due to the effect of the extracts on the heart itself, total peripheral resistance or both. In rats isolated vas deferens, contractile responses to electrical field stimulation (EFS) were decreased by the petals extracts. EFS-induced contractions of vas deferens were shown to be mediated by noradrenaline and adenosine triphosphate (ATP) released as co-transmitters from sympathetic nerves . The ethanolic extract made more pronounced changes in EFS in rats isolated vas deferens whereas in guinea pig ileum, the aqueous extract of the plant was more effective. Crocin analogs isolated from saffron remarkably increased the blood flow in the retina and choroid and facilitated retinal function recovery; therefore, it could be used to treat ischemic retinopathy and/or age-related macular degeneration.
One study suggested that saffron exerted a significant cardioprotective effect by preserving hemodynamics and left ventricular functions. Administration of Crocus sativus extractinpatients who had normal white blood cells (WBC) count, significantly increased WBC compared to crocin or placebo. Moreover, other hematologic factors were not changed significantly during 3 months of the study.
A potent stimulatory effect of Crocus sativus extract and safranal on adrenoreceptors has also been reported. In addition, blocking effect of safranal on muscarinic receptors and the inhibitory effect of Crocus sativus on histamine receptors was reported, which proposed a competitive antagonistic effect for C. sativus on histamine receptors.
An in vitro study showed the inhibitory activity of saffron and crocin on amyloid beta-peptide brillogenesis and its protective action against H2O2–induced toxicity in human neuroblastoma cells. Additionally, administration of saffron (60 mg/kg body weight, i.p.) to normal and aged mice for one week, significantly improved learning and memory. Also, in vitro studies have confirmed the neuroprotective effects of saffron and its constituents in amnesic and ischemic rat models.