ABSTRACT
Eucalyptus globulus L. is used in folk medicine throughout the world and its essential oils are widely used in modern pharmaceutical, food, and cosmetic industries. In this study, E. globulus leaves were extracted using three solvents (methanol, chloroform and hexane). The polyphenolics were quantified with HPLC and the volatiles analyzed by GC/MS with antioxidant, anti-inflammatory and antitumor activities. Results have shown a hierarchy of antioxidant and anti-inflammatory activity for three extracts as hexane > chloroform > methanol extracts with DPPH, FRAP, and oxygen radical absorbance capacity, respectively. A similar order of results was observed for antitumor activity by potato disc and colorimetric assays. The GC/MS analysis led to the identification of 1, 8-cineole (eucalyptol) as a major constituent of methanol (48.2%), chloroform (35.5%), and hexane (5.8%) extracts. Different phenolic acids (gallic acid, ellagic acid, syringic acid, and vanillic acid) and flavonoids (quercetin, rutin, and catechin) were highly abundant in methanol extract. The methanol extract of E. globulus exhibited the maximum antioxidant, anti-inflammatory, and antitumor activities. These results demonstrate E. globulus leaf extracts may be used as a potential source of bioactive compounds with remarkable antioxidant, anti-inflammatory, and antitumor activities.
ABSTRACT
Abstract The ferulic and gallic acid related compounds from natural origin were studied against xanthine oxidase and cyclooxygenase-2 along with their anti-inflammatory activity. The compounds gallic acid, ferulic acid, caffeic acid and p-coumaric acid revealed promising anti-inflammatory activity (30–40% TNF-α and 60–75% IL-6 inhibitory activity at 10 µM). Bioavailability of compounds were checked by in vitro cytotoxicity using CCK-8 cell lines and confirmed to be nontoxic, but found toxic at higher concentration (50 µM). Gallic, ferulic, caffeic acid was demonstrated potential dual inhibition toward xanthine oxidase and cyclooxygenase-2 as calculated by IC50: 68, 70.2, and 65 µg/ml (xanthine oxidase) and 68.5, 65.2, and 62.5 µg/ml (cyclooxygenase-2), respectively. The structure activity relationship and in silico drug relevant properties (HBD, HBA, PSA, c Log P, ionization potential, molecular weight, EHOMO and ELUMO) further confirmed that the compounds were potential candidates for future drug discovery study, which was expected for further rational drug design against xanthine oxidase and cyclooxygenase.