ABSTRACT

Miswak (meswak), a stick used for teeth cleaning, is prepared from the root or the stem of the shrub Salvadora persica. This stick is widely used in the Middle East and various African countries. Its regular use is claimed to prevent caries and periodontal diseases. The oral health promoting activity of miswak could be due to its mechanical tooth cleaning and /or the effects of anti-microbial substances in miswak.

The aim of our study was to quantify thiocyanate levels in miswak aqueous extracts by diffuse reflectance infrared spectrometry. Samples of S. persica stems  and roots, collected from four distant geographical areas in Sudan, were examined. Aqueous extraction of the powdered stem and root samples was performed by soaking the powdered material in sterile de-ionised distilled water. Soaking time used was 4 hrs at 4°C. After filtration, the filtrates were freeze-dried. Yields %s obtained mean (SD) g/g of the stems range between 4.2(0.2) to 4.5(0.6), and of the roots range between 3.1(0.5) to 3.4(0.4). The thiocyanate levels were found to be 8.6 and 5.2 % in root and stem extracts, respectively.

The second derivative infrared spectrum of the extracts indicated that the absorption in the region 2200-1840 cm^-1 arises from the contribution of four different bands. The band at 2039 cm^-1 indicated free thiocyanate and the others above 2039 cm^-1 indicated bonded thiocyanates.