Anti-inflammatory and antioxidant potential of Guaianolide isolated from Cyathocline purpurea : Role of COX-2 inhibition

摘要

Abstract Background Inflammation activated by oxidative stress can cause various diseases, such as asthma, rheumatoid arthritis, cancer, diabetes, etc. Plant constituents with sesquiterpene lactones possess antioxidant and anti-inflammatory properties. Aim To determine the antioxidant and anti-inflammatory potential of isolated phytoconstituent from Cyathocline purpurea Buch-Ham ex D (CP). Don in laboratory animals. Furthermore, to understand the interactions involved in the binding of this compound to cyclooxygenase-2 (COX-2) via computational docking. Methods Phytoconstituent was isolated, purified and well characterized (using IR, NMR, and MS) from ethyl acetate fraction of CP methanolic extract. It was then evaluated for its in-vitro antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H 2 O 2 ) and hydroxyl (OH) radical assays as well as in-vivo anti-inflammatory potential against carrageenan-induced paw edema model in rats. The molecular docking study was performed against the crystal structure of COX-2 to evaluate the binding potential of phytoconstituent towards this enzyme. Results The isolated compound 6α-hydroxy-4 [14], 10 [15]-guainadien-8α, 12-olide (HGN) showed significant ( p 50 values of 76μg/mL. Administration of HGN (10 and 20mg/kg) significantly ( p Conclusions The presence of hydroxyl group in HGN provides a credential to its in-vivo anti-inflammatory and in-vitro antioxidant activities. Furthermore, the good binding affinity of HGN for the active site of COX-2 may open novel vistas in therapeutic option with natural antioxidants like Cyathocline purpurea to treat various inflammatory disorders. Highlights ? 6α-hydroxy-4 [14],10 [15]-guainadien-8α,12-olide isolated from Cyathocline purpurea . ? Guaianolide has molecular formula C15H18O3 with molecular weight of 246. ? Guaianolide showed significant antioxidant activity with IC 50 values of 76μg/mL. ? Guaianolide showed anti-inflammatory potential against carrageenan-induced paw edema. ? Molecular docking with COX-2, it demonstrated good binding (docking score ?8.98).