title: Antitubercular activity of the semi-polar extractives of Uvaria rufa.
abstract: OBJECTIVE
  To investigate the inhibitory activity of the chloroform extract, petroleum ether and chloroform sub-extracts, lead-acetate treated chloroform extract, fractions and secondary metabolites of Uvaria rufa (U. rufa) against Mycobacterium tuberculosis (M. tuberculosis) H(37)Rv.
  
  
  METHODS
  The antituberculosis susceptibility assay was carried out using the colorimetric Microplate Alamar blue assay (MABA). In addition, the cytotoxicity of the most active fraction was evaluated using the VERO cell toxicity assay.
  
  
  RESULTS
  The in vitro inhibitory activity against M. tuberculosis H(37)Rv increased as purification progressed to fractionation (MIC up to 23 μg/mL). The chloroform extract and its sub-extracts showed moderate toxicity while the most active fraction from chloroform sub-extract exhibited no cytotoxicity against VERO cells. Meanwhile, the lead acetate-treated crude chloroform extract and its fractions showed complete inhibitions (100%) with MIC values up to 8 μg/mL. Phytochemical screening of the most active fraction showed, in general, the presence of terpenoids, steroids and phenolic compounds. Evaluation of the antimycobacterial activity of known secondary metabolites isolated showed no promising inhibitory activity against the test organism.
  
  
  CONCLUSIONS
  The present results demonstrate the potential of U. rufa as a phytomedicinal source of compounds that may exhibit promising antituberculosis activity. In addition, elimination of polar pigments revealed enhanced inhibition against M. tuberculosis H(37)Rv. While several compounds known for this plant did not show antimycobacterial activity, the obtained results are considered sufficient reason for further study to isolate the metabolites from U. rufa responsible for the antitubercular activity.
authors.affiliation: Organic Synthesis and Phytochemistry Laboratory, Research Center for the Natural Sciences, University of Santo Tomas, Espana Blvd., Manila 1015, Philippines. allanpatrick_m@yahoo.com
authors.forename: Allan Patrick G
authors.initials: AP
authors.lastname: Macabeo
authors.forename: Florie A
authors.initials: FA
authors.lastname: Tudla
authors.forename: Karsten
authors.initials: K
authors.lastname: Krohn
authors.forename: Scott G
authors.initials: SG
authors.lastname: Franzblau
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D002725:Chloroform; D006801:Humans; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D010679:Philippines / Q000453:epidemiology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D012997:Solvents; D014376:Tuberculosis / Q000188:drug therapy* / Q000453:epidemiology; D031046:Uvaria / Q000737:chemistry
chemical_list: D000995:Antitubercular Agents; D010936:Plant Extracts; D012997:Solvents; D002725:Chloroform