Purpose: To evaluate the antioxidant potential, flavonoids, and total phenols as well as cyanidin 3-glucoside and delphinidin 3-glucoside contents of some Boraginaceae species that grow in Iran.
Methods: The aqueous and ethanol extracts of the plants were prepared. The free radical scavenging
activity of the extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method. Total
phenolic and flavonoid contents of the extracts were assessed by Folin-Ciocalteu and aluminium
chloride colorimetric assays, respectively. Furthermore, cyanidin 3-glucoside and delphinidin 3-glucoside contents of the extracts were determined using high- performance liquid chromatography
(HPLC) method.
Results: The most powerful free radical scavenging activity with 50 % inhibitory concentration (IC
50) of
23.13 ± 1.90 μg mL
-1 was exerted by the ethanol extract of
Nonea caspica
, while the weakest IC
50 of
364.38 ± 14.18 μg mL
-1 was shown by the aqueous extract of
Onosma sericeum
. Total phenolic content
varied among the plants, ranging from 270.33 ± 2.60 to 3.40 ± 0.28 mg GAE g
-1 dry weight. The ethanol
extracts of Nonea caspica and
Anchusa arvensis
displayed the highest total flavonoid content (252.60 ±
1.80 and 29.13 ± 1.05 mg QE g
-1 dry weight, respectively). The highest contents of cyanidin and
delphinidin 3-glucosides were found in the ethanol extracts of Nonea caspica and Anchusa arvensis,
respectively.
Conclusion: The results show that some of the plants have potent antioxidant activities which may
justify the ethno-therapeutic usage of these plants by traditional healers.
