Anticancer and antimicrobial activities of some antioxidant-rich cameroonian medicinal plants

PLoS One. 2013;8(2):e55880. doi: 10.1371/journal.pone.0055880. Epub 2013 Feb 11.

Abstract

Traditional remedies have a long-standing history in Cameroon and continue to provide useful and applicable tools for treating ailments. Here, the anticancer, antimicrobial and antioxidant activities of ten antioxidant-rich Cameroonian medicinal plants and of some of their isolated compounds are evaluated.The plant extracts were prepared by maceration in organic solvents. Fractionation of plant extract was performed by column chromatography and the structures of isolated compounds (emodin, 3-geranyloxyemodin, 2-geranylemodin) were confirmed spectroscopically. The antioxidant activity (AOA) was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching method, the trolox equivalent antioxidant capacity (TEAC), and the hemoglobin ascorbate peroxidase activity inhibition (HAPX) assays. The anticancer activity was evaluated against A431 squamous epidermal carcinoma, WM35 melanoma, A2780 ovary carcinoma and cisplatin-resistant A2780cis cells, using a direct colorimetric assay. The total phenolic content in the extracts was determined spectrophotometrically by the Folin-Ciocalteu method. Rumex abyssinicus showed the best AOA among the three assays employed. The AOA of emodin was significantly higher than that of 3-geranyloxyemodin and 2-geranylemodin for both TEAC and HAPX methods. The lowest IC(50) values (i.e., highest cytotoxicity) were found for the extracts of Vismia laurentii, Psorospermum febrifugum, Pentadesma butyracea and Ficus asperifolia. The Ficus asperifolia and Psorospermum febrifugum extracts are selective against A2780cis ovary cells, a cell line which is resistant to the standard anticancer drug cisplatin. Emodin is more toxic compared to the whole extract, 3-geranyloxyemodin and 2-geranylemodin. Its selectivity against the platinum-resistant A2780cis cell line is highest. All of the extracts display antimicrobial activity, in some cases comparable to that of gentamycin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Anti-Infective Agents / toxicity
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Antineoplastic Agents / toxicity
  • Antioxidants / chemistry
  • Antioxidants / pharmacology*
  • Antioxidants / toxicity
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cluster Analysis
  • Dose-Response Relationship, Drug
  • Humans
  • Inhibitory Concentration 50
  • Microbial Sensitivity Tests
  • Phenol / chemistry
  • Phenol / pharmacology
  • Plant Components, Aerial / chemistry
  • Plant Extracts / chemistry*
  • Plants, Medicinal / chemistry*
  • Spectrum Analysis

Substances

  • Anti-Infective Agents
  • Antineoplastic Agents
  • Antioxidants
  • Plant Extracts
  • Phenol

Grants and funding

JDT acknowledges funding from the Agence Universitaire de la Francophonie (AUF) and the Romanian Ministry of Education and Research through their Eugen-Ionescu fellowship grant. Also acknowledged is funding from the Romanian Ministry for Education and Research grant PCCE 140/2008 (to RSD and EFF) and a PhD scholarship from Contract POSDRU/88/1.5/S/60185– “Innovative doctoral studies in a knowledge based society” (to ACM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.