A cyclooxygenase (COX) inhibitory biflavonoid from the seeds of Semecarpus anacardium.

Semecarpus anacardium Linn., Anacardiaceae, is being most commonly used in India for the treatment of rheumatoid arthritis and other inflammatory disorders. Bioactivity guided fractionation of ethyl acetate extract led to the isolation of major active principle, tetrahydroamentoflavone (THA), a biflavonoid. The in vitro cyclooxygenase (COX-1) catalyzed prostaglandin biosynthesis assay of THA gave an IC(50) value of 29.5 microM (COX-1) and 40.5% inhibition at 100 microg/mL (COX-2). The in vivo carrageenan induced paw edema assay resulted in dose dependent anti-inflammatory effect of THA and the activity was comparable to that of ibuprofen, one of the well known NSAIDs.

Anti-inflammatory, cyclooxygenase inhibitory and antioxidant activities of standardized extracts of Tridax procumbens L.

The standardized EtOAc, MeOH and 70% EtOH extracts of Tridax procumbens aerial parts showed significant inhibition of rat paw edema at a medium dose of 200mg/kg and the EtOAC extract was the most active. These extracts were standardized by HPLC with the help of chemical markers. Further, the extracts were evaluated for COX-1 and COX-2 inhibitory activity and EtOAc extract exhibited the highest inhibition of COX-1 and COX-2 at 50 µg/mL. Cent aurein, centaureidin and bergenin were isolated as COX-1 and COX-2 inhibitory principles from the EtOAc extract. The extracts also exhibited antioxidant activity against DPPH and ABTS free radicals. The anti-inflammatory activity of T. procumbens aerial parts could be at least in part due to COX-1, COX-2 enzyme inhibition and free radical-scavenging activities which may be attributed to the presence of flavonoids and other polyphenols in the extracts.

Design, synthesis, biological evaluation and molecular docking of curcumin analogues as antioxidant, cyclooxygenase inhibitory and anti-inflammatory agents.

Curcuminoids were isolated from Curcuma longa and their pyrazole and isoxazole analogues were synthesized and evaluated for antioxidant, COX-1/COX-2 inhibitory and anti-inflammatory activities. The designed analogues significantly enhance COX-2/COX-1 selectivity and possess significant anti-inflammatory activity in carrageenan induced rat paw edema assay. Pyrazole, isoxazole analogues of curcumin (4 and 7) exhibited higher antioxidant activity than trolox. Molecular docking study revealed the binding orientations of curcumin analogues in the active sites of COX and thereby helps to design novel potent inhibitors.

Cyclooxygenase inhibitory flavonoids from the stem bark of Semecarpus anacardium Linn.

The ethyl acetate extract of stem bark of Semecarpus anacardium showing in vivo anti-in fl ammatory activity in carrageenan induced rat paw edema assay was investigated in order to identify its active compounds. Chemical investigation of the ethyl acetate extract of S.anacardium afforded 3,4,2',4'-tetrahydroxychalcone (butein) and 7,3',4'-trihydroxy fl avone. Evaluation of COX-1 inhibitory activity of 3,4,2',4'-tetrahydroxychalcone and 7,3',4'-trihydroxy fl avone provided the IC(50) values of 28.4 and 36.7 micro M respectively. Further investigation of these compounds for COX-2 inhibitory activity revealed moderate potency towards this enzyme.

Synthesis and evaluation of S-4-(3-thienyl)phenyl-alpha-methylacetic acid.

Herein we report an efficient procedure to synthesize S-4-(3-thienyl)phenyl-alpha-methylacetic acid, an enantiomerically pure intermediate of a recently approved nonsteroidal antiinflammatory cyclooxygenase inhibitor, atliprofen [methyl RS-4-(3-thienyl)phenyl-alpha-methylacetate]. The interactions of the active S-isomer of the acid were theoretically compared with those of S-ibuprofen through molecular docking studies using COX-1 and COX-2 protein structures. The results were corroborated by in vitro and in vivo studies.