Antimicrobial and Antioxidant Properties of Total Polyphenols of Anchusa italica Retz.

Mostafa El Khomsi,Mashail N Alzain,Amine Assouguem,Brahim Bourkhiss,Hamada Imtara,Nurah M Alzamel,Mohammed Kara,Omar Noman,Driss Hmouni,Mahmoud Tarayrah,Anouar Hmamou

doi:10.3390/molecules27020416

Abstract

Anchusa italica Retz has been used for a long time in phytotherapy. The aim of the present study was to determine the antioxidant and antibacterial activities of extracts from the leaves and roots of Anchusa italica Retz. We first determined the content of phenolic compounds and flavonoids using Folin–Ciocalteu reagents and aluminum chloride (AlCl3). The antioxidant activity was determined using three methods: reducing power (FRAP), 2.2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant capacity (TAC). The antimicrobial activity was investigated against four strains of Escherichia coli, two strains of Klebsiella pneumoniae and coagulase-negative Staphylococcus, and one fungal strain of Candida albicans. The results showed that the root extract was rich in polyphenols (43.29 mg GAE/g extract), while the leave extract was rich in flavonoids (28.88 mg QE/g extract). The FRAP assay showed a strong iron reduction capacity for the root extract (IC50 of 0.11 µg/mL) in comparison to ascorbic acid (IC50 of 0.121 µg/mL). The DPPH test determined an IC50 of 0.11 µg/mL for the root extract and an IC50 of 0.14 µg/mL for the leaf extract. These values are low compared to those for ascorbic acid (IC50 of 0.16 µg/mL) and BHT (IC50 0.20 µg/mL). The TAC values of the leaf and root extracts were 0.51 and 0.98 mg AAE/g extract, respectively. In vitro, the extract showed inhibitory activity against all strains studied, with diameters of zones of inhibition in the range of 11.00–16.00 mm for the root extract and 11.67–14.33 mm for the leaf extract. The minimum inhibitory concentration was recorded for the leaf extract against E. coli (ATB:57), corresponding to 5 mg/mL. Overall, this research indicates that the extracts of Anchusa italica Retz roots and leaves exert significant antioxidant and antibacterial activities, probably because of the high content of flavonoids and polyphenols.

Highlights

Aromatic and medicinal plants have been traditionally used in phytotherapy [1,2].Plants are a rich reservoir of active molecules that are used in the production of medicines around the world [3,4]
Other research found that the total polyphenol content of Anchusa italica was 16.2 in a methanolic extract and 12.3 in an aqueous extract [22]
IC50 value for vitamin C was approximately 0.16 ± 0.01 μg/mL, and those for BHT and quercetin were 0.2 ± 0.00 μg/mL and 0.05 ± 0.00 μg/mL, respectively. These results indicate that the radical scavenging capacity of the root extract of Anchusa italica is superior to those of vitamin C, BHT, and the leaf extract, but inferior to that of the natural antioxidant quercetin

Summary

Introduction

Plants are a rich reservoir of active molecules that are used in the production of medicines around the world [3,4] They contain a diversity of phytochemical compounds (polyphenols, flavonoids, tannins, terpenes, etc.) [5]. These phytochemicals are responsible for the biological activities of plants, including their antifungal, antioxidant, and antibacterial properties [6] Anchusa italica Retz is a perennial plant bearing flowers [7]. Kurds used this plant in food preparation; it was used as an antitussive, depurative, diuretic, and anti-inflammatory. The plant is rich in the alkaloid cynoglossine, which is known for its carcinogenic and paralyzing effects [8]

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