Phytochemical characterization and evaluation of antimicrobial effect of leaf and seed extracts of Syzygium Cumini on streptococcus mutans.

Abstract

Dental caries caused by Streptococcus mutans; a facultative anaerobic bacterium is among the major health problems affecting people globally. The disease has affects around 3.1 billion people which is 44% of the world’s population. In Uganda, the prevalence of dental caries is higher in adults with a percentage of 66.7% compared to the 32.5% of children. This study characterized the phytochemicals extracted from seeds and leaves of Syzygium cumini and evaluated their antimicrobial activity against Streptococcus mutans. Phytochemical analysis was carried out and the analysis revealed the absence of alkaloids in all the extracts but tannins, saponins, flavonoids and phenols were present in varying concentrations. Terpenoids were less in seed extracts but absent in the leaf extracts. The plant extracts exhibited varying antimicrobial activity against S. mutans where the ethanolic extracts were more effective than aqueous extracts. The mean inhibition diameters (percentage inhibition) were 17.8±1.9mm (69.8%) for the ethanolic seed extract, 12.7±1.7mm (49.9%) for the ethanolic leaf extract while it was 11±2.3mm (43.1%) for the aqueous seed extract and 7.7±2.5mm (30.1%) for the aqueous leaf extract. The minimum inhibitory concentrations were 7.8mg/ml for ethanolic seed extract, 31.3mg/ml for ethanolic leaf extract and aqueous seed extract and 62.5mg/ml for the aqueous leaf extract. The results indicated the seed extracts to have a higher antimicrobial activity which was attributed to the higher concentration of bioactive phytoconstituents. The results revealed that the different parts (seeds and leaves) of S. cumini have antimicrobial activity against S.mutans though further studies regarding the effect of the extracts on the growth of other oral microbes and also effects of the extracts on the epithelia of the mouth and the gut in general should be studied before the plant can be used in oral health products.