Characterization and Biological Activity of Ethanol Extract of Chrysobalanus icacao seed

Abstract

Bioactive compounds, antioxidant and antimicrobial activities of the ethanol seed extract of Chrysobalanus icacao were investigated using Gas Chromatography-Mass Spectrometry (GC-MS) 1,1-diphenyl-2-pircrylhydrazyl assay (DPPH) free radical scavenging and ferric reducing ability of plasma model and  well in agar diffusion method respectively.  The results obtained from GC-MS analysis indicated that 37 compounds are present in the seed extract. The most abundant compounds identified with respect to their % peak areas were n-Hexadecanoic acid (2.07 %), Octadecanoic acid (1.24%),Isoborneol (0.90%), 2,4-Dimethyl-1-heptene (3.64%), Methane (4.13%), Phenol(1.88%),Methyl-2-[(2-chloroethyl)Thio] (1.60%), Diisooctyl phthalate(1.04%),Methyl ester(2.07%),and 2,3,5,7-tetrathioocatane 3, 3-dioxide (1.63%). The extract showed significant activities in all antioxidant assays compared to the reference antioxidant, ascorbic acid in a dose dependent manner, indicating that C. icacao possessed significant antioxidant ability which may be attributed to high natural abundance of oxygenated and polyphenolic compounds. In DPPH scavenging assay the IC₅₀ value of the extract was found to be 4.45μg/ml while the IC₅₀ for FRAP was   3334 μg/ml. The susceptibility of these isolates towards the seed extract was compared with gentamycin and nystatin, which were used as a positive control for bacteria and fungi respectively. Results obtained showed that the extract was able to inhibit the growth of the isolates at various concentrations. On comparing the zones of inhibition of the extracts with that of the standard (Gentamycin and nystatin) for bacteria and fungi respectively, the results showed that the zone of inhibition of the standard for all the tested isolates was greater than that of the extracts. The results obtained in this study showed that C. icacao is a reservoir of bioactive compounds which may be responsible for its  significant broad spectrum antimicrobial and antioxidant activities.