Antioxidant Potential and Antimicrobial Activity of Ailanthus altissima (Mill.) Swingle Extracts against Pseudomonas aeruginosa

Nadhem Aissani, Mohamed-Amine

Abstract

In recent years, there has been an important development in the search for new natural compounds aimed at replacement of currently antimicrobial and antioxidant chemicals. Ailanthus altissima offers a natural promising alternative for food safety and bioconservation as well as for its antioxidant properties. Total phenolic, flavonoids and tannic compounds values of methanol and water from bark and wood were determined. We demonstrated that aqueous and methanolic extracts of wood and bark of A. altissima were riche in phenols, flavonoids and tannic compounds with higher amount in wood aqueous extract (WAE). The chemical analysis of this latter by High-Performance Liquid Chromatography (HPLC-DAAD) with Diode-Array Detection showed the richness of this extract of phenolic compounds which the most abounded were quinic acid and syringic acid. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), iron reducing power tests and on antioxidant enzymes such superoxide dismutase (SOD) and catalase (CAT) activities. WAE presented the highest antioxidant activity with an IC50 of 122 ± 0.7, 201 ± 1.3 and 140 ± 0.9 µg/mL using DPPH, ABTS and iron reducing capacity tests respectively. As expected, all extracts enhanced the SOD and CAT activity with the best result recorded for WAE. The antimicrobial activity of aqueous and methanolic extracts of wood and bark of A. altissima was assessed against a set of Gram-positive and Gram-negative bacteria using disc diffusion and broth micro dilution methods. We showed for the first time the antimicrobial activity of WAE against Pseudomonas aeruginosa with a MIC of 10.46 mg/mL. Taking into account these results, A. altissima wood aqueous extract can be used as a promising natural antimicrobial and antioxidant tool

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