Activity-guided investigation of Carissa carandas (L.) roots for anti-inflammatory constituents

The present study was structured to investigate the anti-inflammatory potential of the extracts, fractions and compounds isolated from Carissa carandas (L.) roots. Bioassay guided fractionation of methanol extract based on inhibitory potential towards proinflammatory mediators (TNF-, IL-1 and nitric oxide (NO)) led to the identification of stigmasterol (1), lupeol (2), oleanolic acid (3), carissone (4) and scopoletin (5) as potential anti-inflammatory agents. Carissone (4) (IC50=20.1 +/- 2.69g/mL) and scopoletin (5) (IC50=24.6 +/- 1.36g/mL) exhibited significant inhibition of NO production comparable to specific NO inhibitor (L-NAME; IC50=19.82 +/- 1.64g/mL) without affecting the cell viability. Also, 4 and 5 at a concentration of 30M were found to inhibit 41.88-53.44% of TNF- and IL-1. To the best of our knowledge, this is the first report displaying the anti-inflammatory effects of C. carandas (L.) roots, partially mediated by inhibition of TNF-, IL-1 and NO.