Phenolic composition and antioxidant, antimicrobial and cytochrome P450 inhibition activities of Cyperus rotundus tubers

Abstract

The chemical composition of a Cyperus rotundus methanol extract was investigated. The phenol content determined by the Folin–Ciocalteu method was 83.6 ± 5.42 mEGA.g^-1 and the flavonoid content assayed by the AlCl₃ method was 32.65 ± 3.5 mEQ.g^-1. The phenolic composition determined by HPLC-DAD showed the presence of phenolic acids (chlorogenic, caffeic, ferulic, syringic acids) and flavonoids (luteolin, quercetin, apigenin, myricetin). The antioxidant activity of the extract was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH^.) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS^.+) radical scavenging assays and the β-carotene bleaching test. The EC₅₀ values were 5.76 ± 0.83 µg/mL and 18.08 ± 0.6µg/mL for DPPH^. and ABTS^.+, respectively. The antioxidant activity coefficient (AAC) was 670.8 ± 4.2. The antibacterial activity determined by the disc diffusion and submerged culture methods against four Gram negative and two Gram positive bacteria showed effects against all strains. Cytochrome P450 (CYPs) inhibitory activity was evaluated against CYP1A2, CYP3A4 and CYP2D6, which was the most inhibited (IC₅₀ =11.13± 0.04µg/mL).

Keywords: Cyperus rotundus, chemical composition, antioxidant activity, antimicrobial activity, cytochrome inhibition