39th CSN Annual International Conference

Antibacterial and antioxidant activity of Justicia spicigera extracts: Activity enhancement by addition of metal salts

Ohenhen O. N.
  • Ohenhen O. N.
  • Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Nigeria.
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Njoku P. C.
  • Njoku P. C.
  • Department of Chemistry, Alvan Ikoku Federal College of Education, Owerri, Nigeria.
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Igara C. E.
  • Igara C. E.
  • Department of Science Laboratory Tech., Akanu Ibiam Federal Polytechnic, Unwana, Afikpo, Nigeria.
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  • Article Number - B06A952


Justicia spicigera was screened for its phytochemicals. The results showed the presence of alkaloids, flavonoids, tannins, phenols, saponins and steroids. Extracts of J. spicigera prepared with solvents of different polarities (n-Hexane, Chloroform, Methanol, and Ethyl acetate) was used to analyze the antibacterial properties in the absence and in the presence of metal salts. The antioxidant activity was analyzed using 2, 2-diphenyl-1- picrylhydrazyl reagent (DPPH). Quantitative determination of total phenolics was carried out using spectrophotometric method. The results indicate that the tested bacterial strains were most sensitive to the n- Hexane extract but moderately sensitive to the chloroform and methanol extracts. The chloroform, methanol, and ethyl acetate extracts showed potent radical scavenging activities. The ethyl acetate and methanol extracts showed higher total phenolic content than the other extracts. Antioxidant activity was found in the extract-Fe3+ ion combination. The extract-Zn2+ ion combination showed enhanced antibacterial activity against tested bacterial strains compared to the extract alone. The results scientifically establish the efficacy of using the plant extracts and its metal salt combination as antibacterial and antioxidant agents.


Key words: Justicia spicigera, total phenolic content, antibacterial activity, antioxidant.