Anti-inflammatory activity of the lipophilic metabolites from Scolymus hispanicus L

Abstract

The golden thistle, Scolymus hispanicus L. (Asteraceae), is a prickly perennial herb that is widely grown in Mediterranean and in Southeastern Europe. The aim of current study was to isolate and identify the constituents of S. hispanicus L. chloroform fraction, and assess their anti-inflammatory activity in-vitro. Chemical investigation led to isolation of one new guaianolide sesquiterpene; namely iso-japonicolactone (4), three tritepenes namely lupeol acetate (1), lupeol (2), and oleanolic acid (5), and the sterol stigmasterol (3). The isolated compounds demonstrated free radical scavenging activity against DPPH with compound 4 being able to scavenge more than 90% of DPPH radical at 100 µM. Treatment of the peripheral blood mononuclear cells (PBMC) stimulated with phytohaemagglutinin (PHA) with the isolated compounds resulted in a decrease in nuclear factor kappa (NFκB) p65 content in a dose-dependent manner. Compound 4 was the most efficient in decreasing NFκB p65 at the lowest concentration (1 µM), followed by compound 5. In addition, cell treatment with isolated compounds resulted in dose-related reduction of interleukins (IL-6 and IL-1β), and tumor necrosis factor (TNF-α). To the best of our knowledge this is the first report for the isolation of iso-japonicolactone and the detailed study of its anti-inflammatory activity. The potent anti-inflammatory compounds in this study could be considered as a nucleus for developing anti-inflammatory drugs through further biological studies on the molecular level.