Antioxidant, antiradical, and anticholinergic properties of cynarin purified from the Illyrian thistle (Onopordum illyricum L.)

Abstract

Cynarin is a derivative of hydroxycinnamic acid and it has biologically active functional groups constituent of some plants and food. We elucidated the antioxidant activity of cynarin by using different in vitro condition bioanalytical antioxidant assays like DMPD(•+), ABTS(•+), O2(•-), DPPH(•) and H2O2 scavenging effects, the total antioxidant influence, reducing capabilities, Fe(2+) chelating and anticholinergic activities. Cynarin demonstrated 87.72% inhibition of linoleic acid lipid peroxidation at 30 µg/mL concentration. Conversely, some standard antioxidants like trolox, α-tocopherol, butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA) exhibited inhibitions of 90.32, 75.26, 97.61, 87.30%, and opponent peroxidation of linoleic acid emulsion at the identical concentration, seriatim. Also, cynarin exhibited effective DMPD(•+), ABTS(•+), O2(•-), DPPH(•), and H2O2 scavenging effects, reducing capabilities and Fe(2+) chelating effects. On the contrary, IC50 and K(i) parameters of cynarin for acetylcholinesterase enzyme inhibition were determined as 243.67 nM (r(2): 0.9444) and 39.34 ± 13.88 nM, respectively. This study clearly showed that cynarin had marked antioxidant, anticholinergic, reducing ability, radical-scavenging, and metal-binding activities.

Keywords: Antiacetylcholinesterase; Onopordum illyricum; anticholinergic; antioxidant activity; cynarin; radical scavenging.