Saffron (Crocus sativus L.): A Source of Nutrients for Health and for the Treatment of Neuropsychiatric and Age-Related Diseases

Abstract

Saffron (Crocus sativus L.) is a medicinal plant, originally cultivated in the East and Middle East, and later in some Mediterranean countries. Saffron is obtained from the stigmas of the plant. Currently, the use of saffron is undergoing a revival. The medicinal virtues of saffron, its culinary use and its high added value have led to the clarification of its phytochemical profile and its biological and therapeutic characteristics. Saffron is rich in carotenoids and terpenes. The major products of saffron are crocins and crocetin (carotenoids) deriving from zeaxanthin, pirocrocin and safranal, which give it its taste and aroma, respectively. Saffron and its major compounds have powerful antioxidant and anti-inflammatory properties in vitro and in vivo. Anti-tumor properties have also been described. The goal of this review is to present the beneficial effects of saffron and its main constituent molecules on neuropsychiatric diseases (depression, anxiety and schizophrenia) as well as on the most frequent age-related diseases (cardiovascular, ocular and neurodegenerative diseases, as well as sarcopenia). Overall, the phytochemical profile of saffron confers many beneficial virtues on human health and, in particular, on the prevention of age-related diseases, which is a major asset reinforcing the interest for this medicinal plant.

Keywords: age-related diseases; crocetin; crocins; crocus sativus; neuropsychiatric diseases; nutrients; picrocrocin; saffron; safranal.

Figure 1

Main area of the culture of saffron in the world. (Realized by Nathalie Bancod (Université de Bourgogne, Dijon, France) based on the following site illustration: https://www.safranprestige.fr/histoire-du-safran/ (accessed on 6 January 2022)).

Figure 2

Aspects of saffron. Bulbous call cormus and flowers with stigmas are shown. The engraving corresponds to a picture of a botanical board (Illustration from Pierre-Oscar Reveil. Le règne végétal, Flore médicale, L. Guérin, Paris, 1864–1871).

Scheme 1

Biosynthesis of the main compounds (crocetin, crocins, picrocrocin, safranal) of saffron from zeaxanthin; (a) oxidative cleavage; (b) enzymatic modification in saffron; (c) different steps of safranal synthesis (Dominique Vervandier-Fasseur, Université de Bourgogne).

Scheme 2

Hypothetical mechanism of radical formation and of its subsequent stabilization from the carotenoid and terpene chains; (a) radical attack on a carotenoid chain; (b) radical attack on a terpen structure (Dominique Vervandier-Fasseur, Université de Bourgogne).

Figure 3

Beneficial effects of crocin and safranal molecules on inflammation, oxidative stress and apoptosis. In different cellular and animal models, crocin molecules counteract inflammation by reducing the production of COX1 and 2 as well as PGE2, oppose oxidative stress by decreasing the production of ROS and iNOS and by stimulating antioxidant defenses (increase in GSH, GPx, SOD and CAT levels). As for safranal, it reduces the production of pro-inflammatory cytokines and reduces oxidative stress stimulated by H₂O₂. Moreover, crocins induce apoptosis, while safranal activates or inhibits cell death, depending on the models used. The signaling pathways on which these molecules act are still not well known but the PI3K/Akt and MAPK/ERK pathways could be involved. ↗ means increase, ↘ means decrease.

Figure 4

Beneficial effects of saffron constituents (crocetin, crocins and safranal) on neuropsychiatric and age-related diseases.