title: Antimycobacterial potency and cytotoxicity study of three medicinal plants.
abstract: OBJECTIVE
  Mycobacterial infections including tuberculosis, leprosy, and buruli ulcer are among the most prevalent, debilitating, and deadly tropical diseases, especially in Sub-Saharan Africa. The development of drug resistance to the currently available drugs and the poor compliance emphasize the need for new chemotherapeutic agents. This study was designed to evaluate the in vitro activity of Cleistopholis patens, Annona reticulata, and Greenwayodendron suaveolens against Mycobacterium smegmatis. The safety on normal liver cells was also assessed.
  
  
  METHODS
  The crude extracts, fractions, and subfractions were tested against M. smegmatis and for cell cytotoxicity on WRL-68, normal human hepatocyte using microdilution resazurin-based assays. The phytochemical screening was performed using standard methods.
  
  
  RESULTS
  Most of the extracts, fractions, and subfractions inhibited the growth of M. smegmatis with minimum inhibitory concentration (MIC) values ranging from 6.25μg/mL to 125μg/mL. The subfractions P12 and P29 from G. suaveolens twig were more potent with MIC values of 6.25μg/mL and 25μg/mL, respectively. Fruit crude extract and root CH2Cl2fraction from A. reticulata also showed activity with MIC values of 50μg/mL and 25μg/mL, respectively. Crude extracts from the twig and stem bark of C. patens displayed inhibition at MIC values of 125μg/mL and 100μg/mL, respectively. Majority of active extracts showed no cell cytotoxicity, except the extract from C. patens with IC50ranging from 41.40μg/mL to 93.78μg/mL. The chemical investigation of the promising extracts revealed the presence of phenols, alkaloids, glycosides, triterpenes, and acetogenins.
  
  
  CONCLUSIONS
  The results achieved from this preliminary antimycobacterial drug discovery study supported the traditional claims of C. patens, A. reticulata, and G. suaveolens in the treatment of mycobacterial infections. Meanwhile, further fractionation is required to characterize the active ingredients.
authors.affiliation: Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, Accra, Ghana. Electronic address: ptsouh@gmail.com.
authors.forename: Patrick Valere
authors.initials: PV
authors.lastname: Tsouh Fokou
authors.affiliation: Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: Regina
authors.initials: R
authors.lastname: Appiah-Opong
authors.affiliation: Department of Bacteriology, Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: Dorothy
authors.initials: D
authors.lastname: Yeboah-Manu
authors.affiliation: Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: Abena Adomah
authors.initials: AA
authors.lastname: Kissi-Twum
authors.affiliation: Institute of Medical Research and Medicinal Plant Studies (IMPM), Yaoundé, Cameroon.
authors.forename: Lauve Rachel Tchokouaha
authors.initials: LR
authors.lastname: Yamthe
authors.affiliation: Institute of Medical Research and Medicinal Plant Studies (IMPM), Yaoundé, Cameroon.
authors.forename: Aristide Laurel
authors.initials: AL
authors.lastname: Mokale Kognou
authors.affiliation: Department of Animal Experimentation, Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: Phyllis
authors.initials: P
authors.lastname: Addo
authors.affiliation: Department of Biochemistry, University of Yaoundé 1, Yaoundé, Cameroon.
authors.forename: Fabrice Fekam
authors.initials: FF
authors.lastname: Boyom
authors.affiliation: Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: Alexander Kwadwo
authors.initials: AK
authors.lastname: Nyarko
keywords: Bioassay; Fractionation; Medicinal plants; Mycobacteria