In vitro screening of Glyphae brevis (Tiliaceae) for anticholinesterases and antioxidant potentials as a ethnomedicinal component of memory enhancing agent in Niger Delta Nigeria

Abstract

BackgroundThis study investigates the anticholinesterases and antioxidant potential of Glyphae brevis used in ethnomedicine as memory enhancing therapy.MethodsGlyphae brevis crude methanolic leaf extract (GBCMLE), stembark (GBCMSE) and root (GBCMRE), and fractions: ethyl acetate (GB EAF), butanol (GB BUF), aqueous (GB AQF) were investigated for acetylcholinesterase (AChE) inhibitory activity using Ellman's assay and DPPH free radical scavenging activity. The total Phenolic and Flavonoid contents were also examined and expressed in mg Gallic acid (GAE/g) and quercetin (QUER/g) respectively.ResultsThe samples exhibited concentration dependent AChE inhibitions, the leaf: GBCMLE, 52.6%, (IC50 127 μg/mL), GBLEAF, 46.3% (IC50 245 μg/mL), GBL BUF, 24.5% (IC50 425 μg/mL) and GBL AQF, 20.3% (IC50 502 μg/mL); the stem: GBCMSE 68.3% (IC50 19 μg/mL), GBS EAF 172.2% (IC50 172 μg/mL), GBS BUF 65.4% (IC50 21 μg/mL), GBS AQF 85.% (IC50 12 μg/mL); the root: GBCMRE 42.2% (IC50 497 μg/mL), GBR EAF 70.1% (IC50 509 μg/mL), GBR BUF 81.3% (IC50 287 μg/mL) and GBR AQF 60.5% (IC50 521 μg/mL) at a concentration of 200 μg/mL. At this dose, the AChE activities ~20.3 – 52.6%, ~52.2 – 85.6% and ~42.2 – 81.3% for leaf, stem and root respectively of the value observed using eserine 0.02μg/mL. The descending AChE activity is stem > root > leaf.In the DPPH free radicals scavenging assay, highest activity were demonstrated by GBC MLE and GBL EAF, 72.5 ± 3.1 and 65.2 ± 3.2%; for the stem, GBS AQF and GBS BUF, 80.5 ± 3.4 % and 68.3 ± 3.4 %; and the root, GBR BUF and GBR EAF, 78.2 ±3.3% and 67.0 ±3.1% inhibitions of free radicals respectively at 1 mg/mL concentration. The corresponding IC50 were 327, 473, 278, 327, 211 and 473 μg/mL respectively. Similarly, the TPC and TFC are 88.85 and 31.61, 52.36 and 19.45, 75.67 and 27.22, 55.34 and 24.67, 97.0 and 34.33, 51.87 and 19.29 mg Gallic acid GAE/g and quercetin QUER/g respectively. BUF has the highest correlation (r) values, which means that the contents of BUF extracts are the most important for the antioxidant and AChE properties.ConclusionThese results indicate that G. brevis is enriched with phenolic and flavonoid contents that exhibit marked anticholinesterase and antioxidant effects..Support or Funding InformationUniversity of Nottingham Visiting FellowshipThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.