Comparative Analysis of Native Crocus Taxa as a Great Source of Flavonoids with High Antioxidant Activity

Abstract

Native Crocus taxa are abundant in regions with moderate and dry climate; however, their potential in the food industry has thus far been neglected. The objective of this study was to compare the quantitative and qualitative flavonoid content and antioxidant and cytotoxic activity in organs of several populations of Croatian native taxa and assess their potential for application in the food industry. The dominant flavonoids in the native Crocus taxa were kaempferol and quercetin. Tepals contained similar or higher concentrations of flavonoid-glycosides than other organs. Tepals from Cvv1 and Cvv2 populations contained more flavonoid-glycosides than the commonly used spice saffron (C. sativus stigmas). The FRAP antioxidant activity of Cvv1 and Cvv5 tepals was similar to that of standard Trolox. DPPH inhibition of Cvv1 and Cvv3 tepals was within the range of that recorded for saffron. Cvv1 tepals significantly reduced reactive oxygen species in the broadest concentration range (50-1000 μg/ml), and showed considerable antioxidant activity in the ABTS assay, equal to 82% of standard Trolox antioxidant activity. A significantly higher concentration of kaempferol-rutinoside was recorded in this than in other taxa. The flavonoid showed a very strong or strong correlation with antioxidant assays results, and a negative correlation with cellular reactive oxygen species concentration. We therefore presumed that kaempferol-rutinoside is one of the main antioxidant phenolics in Crocus tepals. None of the tested extracts showed cytotoxicity toward Caco-2 cells. The results revealed that Cvv tepals have potential as a food supplement and are a promising material for further food safety tests.

Effect of Hot- and Cold-Water Treatment on Broccoli Bioactive Compounds, Oxidative Stress Parameters and Biological Effects of Their Extracts

“…Additionally, based on this result, we assume that quercetin and kaempferol in broccoli are in an antagonistic relationship with each other during heat stress. Similar relationship between these two flavonols we had previously recorded in Crocus varieties grown at different altitudes [63]. Namely, quercetin:kaempferol ratio was higher in varieties collected at mountains where the UVB radiation was more intense and has a stronger effect on plants.…”

Myricetin preserves rat pial microcirculation from injury induced by cerebral hypoperfusion and reperfusion

“…Among flavones, myricetin, a molecule diffused and abundant in berries, vegetables, teas and wines, manifests interesting antioxidant, anti-inflammatory and anticancer properties [9,10] and is well recognized for its nutraceuticals value. The strong scavenger activity of myricetin was previously documented; Rusak, et al showed that this compound was able to counteract the 1,1′-diphenyl-2-picrilhydrazyl (DPPH) radicals [11], while Husain, et al demonstrated it was able to scavenge hydroxyl (.OH) radicals generated by UV photolysis of hydrogen peroxide [12]. Moreover, myricetin inhibits liposomes peroxidation [13] and its antioxidant properties appeared higher than Vitamin E (d-α-tocopherol) [14].…”

Rumex obtusifolius is a wild food plant with great nutritional value, high content of bioactive compounds and antioxidant activity

“…developed new natural products to the world population. In this way, scientific researchers are important to plants valorization and conservation (Barreira et al, 2015;Šola et al, 2018). Studies concluded that Rumex obtusifolius present antibacterial activity against Escherichia coli (Harshaw et al, 2010), and procyanidins were isolated and classified from Rumex obtusifolius (Spencer et al, 2007).…”