Phytochemical And Antibacterial Analysis Of Indigenous Chewing Sticks, Diospyros Lycioides And Euclea Divinorum

ABSTRACT

Diospyros lycioides and Euclea divinorum commonly known as muswiti and mutakula respectively in Zambezi region are indigenous to Namibia and belong to the family Ebenaceae. The twigs and roots from these plants are commonly used as chewing sticks in Namibia. If properly used, the chewing sticks have proven to be effective in removing dental plaque due to mechanical cleaning and enhanced salivation. Chewing sticks from other plants have been shown to display antimicrobial activities against a broad spectrum of microorganisms. However, there is limited information available in Namibia on the chemical composition, antimicrobial properties and the ability of the plants under study to prevent bacterial adhesion to tooth surface. Therefore, the purpose of this study was to ascertain the phytochemical and antibacterial properties of D. lycioides and E. divinorum and correlate the results obtained to their ethnomedicinal uses as chewing sticks. Powdered twigs and roots of the two plants were exhaustively extracted using dichloromethane/methanol mixture (1:1) at room temperature for 48 hours. Fractions were obtained from crude extracts using vacuum liquid chromatography with solvents of increasing polarity. Antimicrobial activities of the crude extracts and fractions were assessed using the agar overlay, disc diffusion and agar dilution methods against the oral pathogens, Streptococcus mutans and Streptococcus sanguinis. In addition, the effect of fractions on the attachment of oral pathogens to tooth surface were also analyzed using saliva-coated hydroxyapatite beads (S-HA) as a model.