Phytochemical Screening and Antimicrobial Analysis of Vernonia amygdalina and Psidium guajava Stems on Bacteria Associated with Dental Caries

Background: Chewing stick has long been used in many parts of Africa and the Middle East as a means of oral hygiene. Dry stems or Roots of different plants have been used in the process. Stems of Vernonia amygdalina and Psidium guajava are among the commonly used plants in Nigeria in cleansing teeth. Few attempts have been made to screen the antimicrobial activity of the stems of the trees on microorganisms isolated from teeth. Aim of the Study: The aim was to determine the Phytoconstituents and the antimicrobial activity of Vernonia amygdalina and Psidium guajava on Bacteria isolated from human teeth. Materials and Methods: Phytoconstituents of the aqueous and ethanolic extract of the stems of Bitter leaf and Guava tree were determined using standard methods. The antimicrobial activity of the extract against some microorganisms isolated from teeth was determined using agar well diffusion method. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined using standard methods. Results: Phytochemical screening of stems of the two plants revealed the presence of alkaloids, flavonoids, steroids and carbohydrates. Highest zone of inhibition of 9 mm and 10 mm was recorded on the ethanolic extracts of bitter leaf and Guava tree stems on Staphylococcus aureus respectively. MIC and MBC of 50 mg/ml and 100 mg/ml for the ethanolic extracts of Bitter leaf stem on Klebsiella pneumonia, S. aureus and Proteus mirabilis were recorded. For the Guava, MIC and MBC of 50 mg/ml and 100 mg/ml were recorded for the ethanolic extracts were recorded on S. aureus and Proteus mirabilis. Conclusion: Aqueous and ethanolic extracts of both plants show potential antibacterial activity against the microorganisms isolated from human teeth.