Effectiveness of essential oil from the Artemisia herba-alba aerial parts against multidrug-resistant bacteria isolated from food and hospitalized patients

Abstract. Ed-Dra A, Filali FR, Presti VL, Zekkori B, Nalbone L, Elsharkawy ER, Bentayeb A, Giarrtana F. 2021. Effectiveness of essential oil from the Artemisia herba-alba aerial parts against multidrug-resistant bacteria isolated from food and hospitalized patients. Biodiversitas 22: 2995-3005. The World Health Organization has sounded the warning on the diffusion of multidrug resistance (MDR) bacteria, requiring solutions and alternatives to solve the therapeutic failure that may occur. This study aims to evaluate the antioxidant activity and bactericidal effectiveness against MDR bacteria of Artemisia herba-alba essential oil (A-EO) collected from semi-arid region of Morocco. Chemical composition of the A-EO was determined by Gas Chromatography-Flame Ionisation Detector and Gas Chromatography-Mass Spectrometry, while the antioxidant activity was performed by DPPH scavenging activity and ?-carotene bleaching assay. Antibacterial activity of A-EO, performed by disc diffusion assay and broth dilution method, was tested against: four MDR strains (Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium and Enterococcus faecalis) isolated from food matrices, two (Klebsiella pneumonia and Pseudomonas aeruginosa) from hospitalized patients, and Escherichia coli ATCC 25922 as reference strain. Davanone was the main compound among the 17 identified. An antioxidant activity with IC50 of 1.13±0.02 mg/mL, EC50 of 2.12±0.05 mg/mL and RC50 of 0.87±0.02 mg/mL was observed. A weak activity against P. aeruginosa was observed, while it was intermediate or high against the other bacteria. This study confirms that A-EO could be a suitable alternative to antibiotics in the infection treatment related to MDR bacteria.

A New Phytochemical and Anti-oxidant and Anti-inflammatory Activities of Different Lactuca sativa L. var. crispa Extracts

The phytochemical composition of Lactuca sativa L. var. crispa, commonly known as crisphead lettuce, from Morocco has been re-investigated for the presence of oxyprenylated cinnamic acid and coumarin derivatives. In the mean time also the anti-oxidant and anti-inflammatory effects of extracts from leaves obtained by the use of a Soxhlet apparatus have been assessed. The extracts had a high content of polyphenols with remarkable differences ranging from 0.19 to 0.38 mg gallic acid eq/mg, while the content of flavonoids ranged from 3.75 to 9.64 mg catechin eq/g. The hydroalcoholic extract with a polarity index of 5.8 displayed the best anti-oxidant, radical scavenging, and anti-inflammatory activities. The same extracts were screened by reverse-phase HPLC-UV/V analysis for the presence of biologically active oxyprenylated phenylpropanoids. Only 4'-geranyloxyferulic acid was recorded in detectable amounts. Results described herein enforce the nutraceutical value and depict a potential chemopreventive dietary feeding role for crisphead lettuce.