Chemical characterization and anti-inflammatory activity of phytoconstituents from swertia alata

Abstract

Swertia alata C.B Clarke (Gentianaceae) is a well-reported plant in the traditional system of medicine. The present study was intended to isolate the phytoconstituents from the ethanolic extract of the aerial parts of S. alata; and evaluate for in vitro COX-1/COX-2 inhibition activity, in vivo anti-inflammatory and ulcerogenic activity. Phytoisolation involved partitioning of S. alata ethanolic extract into petroleum ether and chloroform soluble fractions using silica gel-based column chromatography. The isolation afforded two phytoisolates, namely oleanolic acid (SA-1) and 3-hydroxylup-12-(13)-ene-17-carboxylic acid (SA-4). Phytoisolates structures were established by melting point, ultraviolet (UV), attenuated total reflection-Fourier-transform infrared (ATR-FTIR), nuclear magnetic resonance (1H-NMR, 13C-NMR and HMBC) and mass spectrometry. Phytoisolates were further evaluated for in vitro cyclooxygenase (COX-1/COX-2) inhibitory activity, in vivo anti-inflammatory and ulcerogenic activity. The study revealed SA-4 (COX-1/COX-2 inhibition activity of 104/61.68 µM with % inhibition of 61.36) to be more effective than SA-1 (COX-1/COX-2 inhibition activity of 128.4/87.25 µM, with % inhibition of 47.72). SA-1 and SA-4, when subjected to ulcerogenic study, exhibited significant gastric tolerance. The current study reports chromatographic isolation and spectrometric characterization of SA-1 and SA-4. The present study concludes that compound SA-4 possess significant anti-inflammatory activity and less irritant property over gastric mucosa with no significant ulcerogenicity in comparison to indomethacin.