Abstract:
This study is aimed to evaluate the phytochemical constituents, antibacterial and
antioxidant activities of the crude extracts of stem bark of C. anisata. The air-dried stem bark
was powdered and extracted successively with petroleum ether, ethyl acetate and methanol. The
semi-solid matter was separated by filtration and then the filtrates were concentrated using a
rotary evaporator. The extract was subjected to a preliminary phytochemical screening test
using standard procedures and the result showed the presence of alkaloid, tannins, terpenoids,
flavonoids, phenolics, glycosides, steroids and anthraquinones and absence of saponin.
Antibacterial activity of the crude extract was determined by using the Agar disc diffusion
method against four bacterial strains (two gram positive): Staphylococcus aureus, Streptococcus
pyogenes and two gram negative: Escherichia coli, Klebsiella Pneumonie. The methanol extract
of the stem bark of C. anisata showed a significant inhibition zone on all of the selected bacteria.
While ethyl acetate extract had medium inhibition on all of the selected bacteria. Each crude
extract was screened for antioxidant activity by the DPPH assay method and FRAP assay
method. Aluminum chloride colorimetric method was used to determine the flavonoid contents in
these extracts. The results showed that the methanol extract of the stem bark exhibited the
highest antioxidant activity of 77.77 % in DPPH with an IC 50% value of 41.3 ppm. In FRAP
assay 69.11% with an IC 50% value of 51.498 ppm, which appeared to contain more
flavonoid contents 127.5 mg QE /g of sample. The results of this study showed that the stem bark
of C. anisata constitute phytochemicals that possess antibacterial and antioxidant activities and
can serve as a potential source in search of plant-based antibiotics and natural antioxidants.