Anti-bacterial and anti-oxidant activities of leaf extracts of Combretum vendae (Combretecacea) and the isolation of an anti-bacterial compound.
BACKGROUND
Combretum vendae A.E. van Wyk (Combretaceae) is used for the treatment of bacterial related infections and oxidative related diseases by indigenous people of South Africa. Dried leaves extracts of C. vendae were investigated for bioactivity against a variety of bacterial strains and their antioxidant potential evaluated.


METHODS
Constituents of leaf material were serially extracted using solvents of varying polarities, TLC chromatograms of the fractions were sprayed with 2,2 diphenyl-1-picrylhydrazyl (DPPH) to determine the presence of antioxidant compounds. Bio-autography was used to determine the number of antibacterial compounds active against Staphylococcus aureus, Enterococcus faecalis, Eschericha coli and Pseudomonas aeruginosa. Minimum inhibitory concentration (MIC) values were determined using serial microplate dilution method. The chloroform fraction was subjected to bio-assay guided column chromatography to isolate the active compound.


RESULTS
The mass extracted by different solvents was below 10% dry weight. MIC values for different extracts against different pathogens ranges from 0.08 to 0.64 mg/ml. The compound isolated was identified as acacetin having an Rf value of 0.28 following elution in the Ethanol: Methanol: Water [E: M: W (10: 1.35: 1 v/v). Acacetin had MIC values ranging from 0.16 to 0.35 mg/ml.


CONCLUSIONS
We report for the first time the isolation of acacetin as the main antibacterial compound from the leaves of Combretum vendae.
Phytomedicine Programme, Department of Para-clinical Sciences, University of Pretoria , Private Bag X04, Onderstepoort, 0110.
Nancy Patience Motlalepula
NP
Komape
Phytomedicine Programme, Department of Para-clinical Sciences, University of Pretoria , Private Bag X04, Onderstepoort, 0110.
Mutalib
M
Aderogba
University of Limpopo, Department of Biochemistry, Microbiology and Biotechnology, Private Bag X1106, Sovenga, 0727.
Victor Patrick
VP
Bagla
University of Limpopo, Department of Biochemistry, Microbiology and Biotechnology, Private Bag X1106, Sovenga, 0727.
Peter
P
Masoko
Phytomedicine Programme, Department of Para-clinical Sciences, University of Pretoria , Private Bag X04, Onderstepoort, 0110.
Jacobus Nicolaas
JN
Eloff
D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001713:Biphenyl Compounds / Q000378:metabolism; D029765:Combretum / Q000737:chemistry*; D013293:Enterococcus faecalis / Q000187:drug effects; D047309:Flavones / Q000302:isolation & purification / Q000494:pharmacology*; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests; D010851:Picrates / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013019:South Africa; D013211:Staphylococcus aureus / Q000187:drug effects
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D047309:Flavones; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl; C023717:acacetin
Anti-oxidant; Bio-autography; Combretum vendae; Minimum Inhibitory Concentration; Phytochemical analysis; acacetin