Artemisia campestris phenolic compounds have antioxidant and antimicrobial activity

Wided Megdiche-Ksouri, Najla Trabelsi, Khaoula Mkadmini, Soumaya Bourgou, Amira Noumi, Mejdi Snoussi, Rahma Barbria, Olfa Tebourbi, Riadh Ksouri

Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-Lif, Tunisia.

Abstract

Artemisia campestris subsp. maritima, locally named as “T’gouft” is used as decoction for its anti-inflammatory, antirheumatic, antivenom and antibacterial activities. An efficient and fast technique has been achieved for the screening of the major phenolics in methanolic crude extract (MCE) and two soluble fractions; ethyl acetate (EAF) and water (WF) fractions, from the shoot of A. campestris by LC–MS methods using time-of-flight. A total of 39 molecules were detected and tentatively identified, including coumarins, flavones, flavonols, phenolic acids and sesquiterpenes. Twenty-four of them were identified for the first time in this species. The major phenolic compounds are principally luteolin-7-O-rutinoside in MCE, rhamnetin and isorhamnetin in EAF, hydroxycoumarin and kaempferol rutinoside in WF and three di-O-caffeoylquinic acid isomers in all extracts. Moreover, total phenolic, flavonoid and tanin contents were established and three in vitro tests were assessed to assess the antioxidant activity. Agar disk diffusion technique was used to evaluate the antimicrobial activity against 14 pathogen strains. Concerning the results of antioxidant assays, MCE, and EAF at lesser extends, displayed the highest antioxidant capacity (IC50 values are equal to 6 and 10 μg/ml for DPPH test, respectively). Besides, EAF was more potent and showed an appreciable antimicrobial activity mainly against Bacillus thuringiensis (inhibition zone (IZ) = 18 mm) and Vibro vulnificus (IZ = 16 mm), while, MCE more active against Listeria monocytogenes (IZ = 13.5 mm). The relevant antioxidant and antibacterial activities of MCE and EAF corroborated with their chemical compositions dominated by flavonoids. This finding suggests that A. campestris is a promising plant for industry and can be used as additive and conservative to preserve food spoilage.

Graphical abstract

Keywords: Artemisia campestris; Antioxidant activity; Antimicrobial capacity; Flavonoids; LC–ESI-TOF-MS; Phenolic compounds.