Paper Information

Journal:   AVICENNA JOURNAL OF PHYTOMEDICINE (AJP)   2017 , Volume 7 , Number 1; Page(s) 80 To 92.
 
Paper:  IN VITRO AND IN VIVO ANTIOXIDANT POTENTIALS OF ALCHORNEA FLORIBUNDA LEAF EXTRACT, FRACTIONS AND ISOLATED BIOACTIVE COMPOUNDS
 
Author(s):  AJAGHAKU DANIEL LOTANNA, OBASI OKECHUKWU, UMEOKOLI BLESSING OGECHUKWU, OGBUATU PETER, NWORU CHUKWUEMEKA SYLVESTER, ILODIGWE EMMANUEL EMEKA, CHIEDU OKOYE FESTUS BASDEN*
 
* DEPARTMENT OF PHARMACEUTICAL AND MEDICINAL CHEMISTRY, FACULTY OF PHARMACEUTICAL SCIENCES, NNAMDI AZIKIWE UNIVERSITY, AWKA, ANAMBRA STATE, NIGERIA
 
Abstract: 

Objective: Alchornea floribunda leaves are widely used in ethnomedicine for the management of immuno-inflammatory disorders. We investigated the in vivo and in vitro antioxidant activity of the leaf extract, fractions and isolated compounds of A. floribunda.
Materials and Methods: The ethyl acetate fraction of the methanol leaf extract was subjected to several chromatographic separations to isolate compounds 1-4. The structures of the isolated compounds were elucidated by a combination of 1D and 2D NMR and mass spectrometry. Oxidative stress was induced with carbon tetrachloride (CCl4). Further analysis on the isolated phenolic compounds were done using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and hydrogen peroxide scavenging activity tests.
Results: The ethyl acetate fraction at 200 mg/kg produced significant (p<0.05) elevations of catalase enzyme activity and a significant (p<0.05) reduction in serum malondialdehyde. The chemical investigation of the ethyl acetate fraction led to the isolation of three flavans, (-) cathechin (1), (-) epicathechin (2), (+) epicathechin (3) and a flavanone, 2R, 3R dihydroquercitin (4). In hydrogen peroxide scavenging assay, (-) epicathechin exhibited an EC50 value of 8
mg/ml, similar to the standard ascorbic acid (EC50=8 mg/ml). (-) epicathechin showed scavenging of DPPH radical with EC50 value of 19 mg/ml while in the FRAP assay, it had EC50 value of 46 mg/ml which was lower than that of the standard, ascobic acid (EC50=66 mg/ml).
Conclusion: The medicinal uses of A. floribunda may be due to the antioxidant activities of its phenolic compounds.

 
Keyword(s): ALCHORNEA FLORIBUNDA, ANTIOXIDANT ACTIVITY, FLAVANS, FLAVANONE