Chemical composition of essential oil from invasive Moroccan Cyperus rotundus L., in vitro antimicrobial and antiradical activities, and in silico molecular docking of major compounds on drug efflux pumps

For centuries, invasive Cyperus rotundus L. (C. rotundus) rich in secondary metabolites has received greater attention in many civilizations as source of nutrients and pharmaceutical drugs. In Morocco, the plant is of traditional reputation especially in medicine and cosmetic applications. The present work aimed to evaluate the antibacterial and antifungal activities of the essential oil from Moroccan C. rotundus rhizomes against bacterial strains of Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), and fungal strains of Aspergillus brasiliensis (A. brasiliensis) and Candida albicans (C. albicans), as well as its antiradical activity. The C. rotundus essential oil comprised 49 identified compounds, including longiverbenone, cyperotundone, (-)-eudesma-1,4(15),11-triene (eudesmatriene), β-copaen-4α-ol, humulene epoxide 2 and α-copaene as the most abundant. The essential oil weakly scavenged 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radicals, and was active against all tested microorganisms with an inhibition concentration ranging from 1.53 to 49 mg/mL. In silico molecular docking revealed that the major compounds involved hydrophobic interactions to bind efficiently with NorA, AcrB and Cdr1p drugs efflux transporters as candidate targets to combat drugs resistance, in addition to have a remarkable competitivity with standard inhibitors chlorpromazine and fluconazole. The C. rotundus essential oil marked an interesting antimicrobial activity, even more on gram-negative E. coli. This could be attributed to its major identified compounds, including eudesmatriene, β-copaen-4α-ol and longiverbenone that also illustrated a modulator agent profile encouraging for further studies on their potential use in combination treatment.