Antimicrobial and antioxidant activities of methanol extracts of Evax pygmaea (Asteraceae) growing wild in Tunisia

Abstract

Antimicrobial activity of methanolic extracts obtained from the aerial parts of Evax pygmaea was tested against five bacteria and two strains of phytopathogenic fungi using the agar diffusion and broth microdilution methods. Antioxidant properties were evaluated through the ability of the different fractions to scavenge the stable ABTS (2,2 0 -azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (1,1-dip henyl-2-picrylhydrazyl) radicals. The TEAC (Trolox Equivalent Antioxidant Capacity) and IC 50 values of the fractions were calculated and compared. The experimental data indicated that all fractions exhibit moderate to appreciable antibacterial activities against all Gram-positive cocci and Gram-negative rods except Pseudomonas aeruginosa, but no antifungal activity was observed. Ethyl acetate and methanol fractions were found to cause significant free radicalscavenging effects in both assays. These results may suggest that E. pygmaea could be used as a natural preservative ingredient in the food and/or pharmaceutical industries.

A Comparative Study on the Total Antioxidant and Antimicrobial Potentials of Ethanolic Extracts from Various Organ Tissues of <i>Allium</i> spp.

“…The antioxidant activities measured in the TEAC assay also significantly correlate with the DPPH IC 50 value (r 2 = 0.92), as shown in Figure 3(b). This finding, which indicated that both the DPPH IC 50 value and the TEAC assay could be used simultaneously to determine the antioxidant activities of Allium extracts, is supported by the findings of many other similar experiments [9,14,22,23].…”

“…The experiments were run in triplicate, and the developing inhibition zones were compared with those of the reference discs. In addition, the minimal inhibitory concentration (MIC) of the samples was determined by the broth dilution method using the serially diluted Allium extracts as described [6,9]. Then, bacterial cultures were prepared in a nutrient broth and incubated at 37˚C for 24 h. The bacterial cultures were adjusted with sterilized saline to bring the concentration to 10 7 mL −1…”

“…Polyphenols and quercetin in plants have been reported to be the major compounds exhibiting antioxidant activity [4,9]. In addition, the antioxidant activity of quercetin and its functional effects have been fully demonstrated in a few previous studies [10,11].…”

Antifungal Activities of Commercial Rice Wine Extracts of Taiwanese <i>Allium fistulosum</i>

“…These strains were purchased from the Bioresource Collection and Research Center of the Food Industry Research Institute in Hsinchu City, Taiwan. A tube dilution test [15] and an agar disc diffusion test [16] [17] were performed to study the antifungal activity of A. fistulosum extracts against the aforementioned seven fungal strains. Fifty microliters of the A. fistulosum extract at 1 mg/ml was applied to an ethanol-sterilized paper disc (8 mm in diameter) and placed onto the PDA agar plates.…”

Antibacterial and antifungal activities of crude plant extracts from Colombian biodiversity

“…(Asteraceae) that was the most active against S. aureus; while, the chloroform extract resulted less potent against the Gram-positives S. epidermidis and Micrococcus luteus (Boussaada et al 2008).…”