Assessment of Endemic Cota fulvida (Asteraceae) for Phytochemical Composition and Inhibitory Activities against Oxidation, alpha-Amylase, Lipoxygenase, Xanthine Oxidase and Tyrosinase Enzymes

In the present work, chemical compositions of essential oil and methanol extract of endemic Cota fulvida (Grierson) Holub were investigated as well as their antioxidant, antidiabetic, antiinflammatory and antimelanogenesis potent. The phytochemical analyses have been performed with GC-MS/FID and LC-MS/MS techniques. The essential oil was characterized with hexadecanoic acid (25.6 %), camphor (6.1 %), caryophyllene oxide (5.3 %), 1,8-cineole (4.9 %) and humulene epoxide (3.9 %). In the extract, phenolic acids, phenylpropanoid dimer and flavonoids were detected. The major constituents of the extracts were found to be 5-feruloylquinic acid, caftaric acid, 3,5-O-dicafeoylquinic acid and quercetin rutinoside. The antioxidant activities of the oil and extract were evaluated through scavenging of free radicals, inhibition of linoleic acid peroxidation and superoxide anion radical (O2-) generated by xanthine - xanthine oxidase (XO) system. The extract showed free radical scavenging activity (IC50 0.131 mg/mL), Trolox equivalent antioxidant capacity (1.33 mM) and inhibited (Inh. 36.3 %) peroxidation of lipids. The oil and extract demonstrated significant hypoglycemic activity via inhibition of porcine pancreatic a-amylase. The antiinflammatory effects of the oil and extract via inhibition of 5-LOX enzyme were found as 53.7 % and 23.9 %, respectively. The extract demonstrated moderate inhibitory effect (23.3 %) on oxidation of L-DOPA via inhibition of tyrosinase enzyme.