Identification of Compounds of Crocus sativus by GC-MS and HPLC/UV-ESI-MS and Evaluation of Their Antioxidant, Antimicrobial, Anticoagulant, and Antidiabetic Properties

Abstract

In order to valorize the species Crocus sativus from Morocco and to prepare new products with high added value that can be used in the food and pharmaceutical industry, our interest was focused on the phytochemical characterization and the biological and pharmacological properties of the stigmas of this plant. For this purpose, the essential oil of this species, extracted by hydrodistillation and then analyzed by GC-MS, revealed a predominance of phorone (12.90%); (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-methanol (11.65%); isopropyl palmitate (9.68%); dihydro-β-ionone (8.62%); safranal (6.39%); trans-β-ionone (4.81%); 4-keto-isophorone (4.72%); and 1-eicosanol (4.55%) as the major compounds. The extraction of phenolic compounds was performed by decoction and Soxhlet extraction. The results of the determination of flavonoids, total polyphenols, condensed tannins, and hydrolyzable tannins determined by spectrophotometric methods on aqueous and organic extracts have proved the richness of Crocus sativus in phenolic compounds. Chromatographic analysis by HPLC/UV-ESI-MS of Crocus sativus extracts revealed the presence of crocin, picrocrocin, crocetin, and safranal molecules specific to this species. The study of antioxidant activity by three methods (DPPH, FRAP, and total antioxidant capacity) has proved that C. sativus is a potential source of natural antioxidants. Antimicrobial activity of the aqueous extract (E0) was investigated by microdilution on a microplate. The results have revealed the efficacy of the aqueous extract against Acinetobacter baumannii and Shigella sp. with MIC ≤ 600 µg/mL and against Aspergillus niger, Candida kyfer, and Candida parapsilosis with MIC = 2500 µg/mL. Measurements of pro-thrombin time (PT) and activated partial thromboplastin time (aPTT) in citrated plasma obtained from routine healthy blood donors were used to determine the anticoagulant activity of aqueous extract (E0). The anticoagulant activity of the extract (E0) studied showed that this extract can significantly prolong the partial thromboplastin time (p < 0.001) with a 359 µg/mL concentration. The antihyperglycemic effect of aqueous extract was studied in albino Wistar rats. The aqueous extract (E0) showed strong in vitro inhibitory activity of α-amylase and α-glucosidase compared with acarbose. Thus, it very significantly inhibited postprandial hyperglycemia in albino Wistar rats. According to the demonstrated results, we can affirm the richness of Crocus sativus stigmas in bioactive molecules and its use in traditional medicine.