Antimicrobial activity of Diospyros villosa root

Diospyros villosa L. (de Winter) root is used as toothbrush and to treat oral infections in Mozambique. This medicinal plant is known as „mulala“ a vernacular name also common to Euclea natalensis A.DC. root, another Ebenaceae species with the same traditional uses. The antimicrobial activity of E. natalensis root against diverse microorganisms is already determined, and naftoquinones were identified in this plant. ^1,2,3,4 Hereby we present the results of the antimicrobial activity of a D. villosa root hydroethanol extract (70% ethanol, Dvr) and corresponding liquid-liquid fractions: n-hexane (Dvrh), ethyl acetate (Dvre), n-buthanol (Dvrb) and water (Dvrw). A preliminary chemical characterization of this extract and fractions was also done. The MIC of each extract and fraction was determined against Candida albicans ATCC 10231, Enterococcus faecalis ATCC 435628, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Micrococcus luteus ATCC 10240 and Staphylococcus aureus ATCC 25923. Dvr extract shows antimicrobial activity against all tested strains (MIC between 62.5 and 312.5µg/ml) except P. aeruginosa, as well as the fractions Dvrh (MIC between 31.2 and 62.5µg/ml) and Dvre (MIC between 15.6 and 62.5µg/ml). Triterpenes and hydrolysable tannins were identified as main compounds of this extract and fractions. Naftoquinones were vestigial compounds of the active extract and fractions. As far as we know, this is the first study concerning the chemical and biological characterization of D. villosa root.

References: 1. Lall, N. et al. (2000)J. Ethnopharmacol. 72:313–316.

2. Lall, N. et al. (2006). S. Afr. J. Bot. 72:579–583.

3. van der Kooy F. et al. (2006) S. Afr J. Bot. 72:349–352.

4. Lall N. et al. (2001)J. Ethnopharmacol. 78:213–216.