title: Antioxidant, antitumor and antimicrobial activities of the crude extract and compounds of the root bark of Allanblackia floribunda.
abstract: BACKGROUND
  Allanblackia floribunda Oliver (Guttiferae) is an African medicinal plant used traditionally to treat a variety of ailments.
  
  
  OBJECTIVE
  We investigated the antitumor, radical scavenging, antimycobacterial, antibacterial and antifungal activities of the root bark extract of A. floribunda and three isolated phenolics, namely 1,7-dihydroxyxanthone (1), morelloflavone (2) and 7'-O-glucoside of morelloflavone (3).
  
  
  METHODS
  The 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay was used for antioxidant tests, while crown gall tumor assay was used for assay of antitumor activity. The p-iodonitrotetrazolium chloride (INT) colorimetry and Microplate Alamar Blue Assay (MABA) were used for antimicrobial investigations.
  
  
  RESULTS
  Moderate tumor reducing activity was observed with the extract, while better activities were recorded with compounds 2 and 3. The antimycobacterial and antitumor activities of the extract are being reported for the first time. The DPPH radical scavenging test showed that all the studied samples were able to scavenge more than 50% of the free radical, with compound 3 showing the best inhibitory activity (IC(50) of 49.08 µg/mL). Compounds 1 to 3 prevented the growth of Mycobacterium smegmatis and both extract and compound 2 were active on M. tuberculosis. The lowest MIC value for the extract (9.76 μg/mL) was recorded against Enterobacter aerogenes while the corresponding value for the compounds (4.88 µg/mL) was obtained with compound 2 on Trichophyton rubrum.
  
  
  CONCLUSIONS
  The overall results of the present work provide baseline information for the potential use of the root bark extract of A. floribunda as an antimicrobial, antitumor and antioxidant phytomedicine.
authors.affiliation: Department of Biochemistry, University of Dschang, Cameroon. kuetevictor@yahoo.fr
authors.forename: Victor
authors.initials: V
authors.lastname: Kuete
authors.forename: Anatole G B
authors.initials: AG
authors.lastname: Azebaze
authors.forename: Armellet
authors.initials: A
authors.lastname: Mbaveng
authors.forename: Edwige L
authors.initials: EL
authors.lastname: Nguemfo
authors.forename: Emmanuel T
authors.initials: ET
authors.lastname: Tshikalange
authors.forename: Pierre
authors.initials: P
authors.lastname: Chalard
authors.forename: Augustin E
authors.initials: AE
authors.lastname: Nkengfack
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D028084:Clusiaceae / Q000737:chemistry*; D020128:Inhibitory Concentration 50; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests; D024301:Plant Bark; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology; D018517:Plant Roots
chemical_list: D000890:Anti-Infective Agents; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D010936:Plant Extracts