Bioactivity Guided Evaluation of Antinociceptive and Anti-inflammatory Properties of Cnestis ferruginea Vahl ex DC (Connaraceae)
Cnestis ferruginea Vahl ex DC (Connaraceae) (CF) is a shrub widely used in traditional African Medicine (TAM) for the treatment of various painful and inflammatory conditions.
This study sought to isolate, identify and investigate the anti-inflammatory and antinociceptive activity of the active constituents of CF through bioassay guided fractionation. The crude methanolic root extract of CF was sequentially fractionated into four sub extracts (chloroform, ethylacetate, n-butanol and the remaining aqueous fraction). The aqueous – butanol fractions having showed significant inhibition of inflammation and pain was subjected to fractionation through successive column chromatography on silica gel 60–120 mesh, eluted with a gradient of CHCl3- MeOH.
Sixty five fractions were collected; fractions with similar TLC profile were grouped into seven major fractions (1–7). Fraction 4 being most active in bioassay was rechromatographed to yield CF-2 and CF-5.
The effect on inflammatory mediators was studied in rat astrocytoma cells (C6), nitrite release in culture supernatant, ROS in cells and TNF-α in cell lysate were estimated.
The methanolic extract, aqueous and n-butanol fraction showed significant (p<0.05, p<0.01, p<0.001) inhibition of acute inflammation, peripherally and centrally mediated forms of pain in the bioassay procedures.
The aqueous/n-butanol fraction afforded two active major compounds, identified as amentoflavone (CF-2) and an amino acid compound (CF-5) following various spectroscopic experiments. CF-2 and CF-5 significantly attenuated nociception, inflammation, nitrite release, ROS generation and down regulated TNF-α.
This study confirmed the anti-inflammatory and antinociceptive activity of Cnestis ferruginea and its active constituents based on folkloric uses.