Two new polyoxygenated flavonoids from Blumea eriantha DC, methanol extract and their anti-proliferative activity.

Two new flavonoids, 3, 3', 4' -Trihydroxy- 6, 7, 8 -trimethoxy flavone (1) and 3-Hydroxy-6, 7, 8, 3', 4'-pentamethoxy flavone (2) have been isolated from the methanol extract of Blumea eriantha DC. The structures of these compounds were determined on the basis of spectroscopic techniques such as IR, MS, 1 D, and 2 D NMR spectroscopy. The compounds (1) and (2) were tested for their anti-proliferative activity on NCI-H23 cell line. A standard drug Paclitaxel showed potent anti-proliferative effect (56%) at 100 nM concentration after 24 h treatment whereas compound (2) did not show any anti-proliferative effect. Only compound (1) showed significant reduction in cell viability at concentration 25773 nM (89%) and 257731 nM (68%) after 24 h when compared with 0.1% DMSO. The compound (1) showed significant but much lower reduction in cell viability as compared to the standard drug Paclitaxel.

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

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 (H2O2) 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<0.001) antioxidant activity with IC50 values of 76µg/mL. Administration of HGN (10 and 20mg/kg) significantly (p<0.001) reduced the increased paw volume after subplantar administration of carrageenan. It also exhibits good binding affinity towards with COX-2 with a docking score of -8.98 and Glide binding energy of -36.488kcal/mol shedding light on the potential mechanism of anti-inflammatory action. 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.