Abstract
Introduction: The antimicrobial properties of Miswak (Salvadora persica) are well
documented, and the use of its extracts in the formulation of toothpastes and mouth
rinses are well established. Most of the literature agrees that the organic extracts
are more effective than aqueous extracts. Aims: The aim of the study was to prepare
aqueous Miswak extracts using three different methods. The difference between the
methods is the amount of heating used for their preparation. Furthermore, to evaluate
stability during storage of such extracts, their pH, and their antimicrobial activity.
Materials and Methods: Miswak extracts were prepared by maceration, infusion, and decoction methods, followed
by evaluation of their extraction efficiency, stability, pH, viscosity, and antimicrobial
activity. Results: A correlation was found between pH of extracts and their viscosity. The pH of extract
increases to 6.5 when extensive heat was used during preparation, which is close to
the normal pH of saliva and oral cavity. The accompanied increase in viscosity was
an indication of increased extraction efficiency. Suppression of freezing point confirmed
such observation for extracts prepared by decoction. The only positive antibacterial
activity was observed for decoction extract, but it was less than that of chlorhexiden.
For minimum inhibitory concentration estimation, it was found that almost 50% w/v
of the extract must be used to provide the minimum microbial inhibitory effect. Conclusions:
Miswak components appear to be thermostable ingredients, and the method of decoction
can produce stable and effective Miswak extract.
Key-words:
Antimicrobial activity - aqueous-heat extraction - miswak
