Identification of chemopreventive components from halophytes belonging to Aizoaceae and Cactaceae through LC/MS - Bioassay guided approach

Six halophytes, namely, Aptenia cordifolia var. variegata, Glottiphyllum linguiforme, Carpobrotus edulis, Ferocactus glaucescens, F. pottsii and F. herrerae were investigated for chemopreventive effect. Prioritization of most promising plant for further investigation was carried out through an integrated liquid chromatography-high resolution electrospray ionization mass spectrometry profiling - bioassay guided approach. NAD(P)H: quinone oxidoreductase-1 (NQO-1) induction in cultured murine hepatoma cells (Hepa-1c1c7) and inhibition of nitric oxide (NO) production in lipopolysaccharide-activated macrophages (RAW 264.7) were carried out to investigate chemopreventive effect. Bioassay data revealed that F. herrerae, A. cordifolia, C. edulis and F. glaucescens were the most active with 2-, 1.7-, 1.6- and 1.5-folds induction of NQO-1 activity. Only F. glaucescens exhibited >50% inhibition of NO release. LCMS profiling of the F. glaucescens revealed its high content of flavonoids, a known micheal acceptor with possible NQO-1 induction, as proved by quantitative high-performance liquid chromatography analysis. Thus, the extract of F. glaucescens was subjected to chromatographic fractionation leading to the isolation of four compounds including (i) 2S-naringenin, (ii) trans-dihydrokaempferol (aromadendrin), (iii) 2S-naringenin-7-O-β-d-glucopyranoside and (iv) kaempferol-7-O-β-d-glucopyranoside (populnin). The current study through an LCMS dereplication along with bio guided approach reported the activity of populnin as NO inhibitor and NQO-1 inducer with promising chemopreventive potential.