Evaluation of the Antibacterial Properties of the Hydro-Ethanolic Leaf and Stembark of Psidium guajava (Myrtaceae) on Cariogenic and Periodontopathic Bacteria

Abstract

Background: Caries and periodontal diseases are major public health problems. Due to increase in bacterial resistance to antibiotics, there is a need to promote the known potential of plants and search for new anti-infectious substances as therapeutic alternatives to antibiotics.
 Aims: This study was aimed at evaluating the antibacterial property of the hydro-ethanolic leaf and stem bark extracts of Psidium guajava on cariogenic and periodontopathic bacteria.
 Methodology: This was an experimental study that took place in the Laboratory of Chemistry and Microbiology (Clinique Universitaires des Montagne (CUM)) of Bangangté between January to June 2020. They were dried in shade for 3 weeks and ground to obtain a coarse powder. The dried powders were macerated for 72 hours in a water-ethanol mixture (30:70). Then, the phytochemical screening and quantification of the total polyphenol content followed. Microdilutions were used to determine the minimum inhibitory concentrations (MIC) of guava. Müller Hinton agar was used for obtaining the minimum bactericidal concentrations (MBC) and the determination of inhibition diameters of the bacteria.
 Results: Extraction yields of 17.36g and 42.55g were obtained for leaf and stem bark, respectively. The phytochemical screening revealed the presence of various secondary metabolites among which the total phenol content was quantified at 236.1878 and 255.7682 mg equivalent of gallic acid per gram for leaf and stem bark, respectively. The carious bacteria isolated were: Streptococcus mutans, Actinomycetes viscosus and Lactobacillus acidophilus.While, the periodontal bacteria were: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum ,Tannerella forsythensis. The results obtained showed that the combined extracts of leaf and stem bark had an activity higher than that of the stem bark which in turn had a higher activity than the leaves. 
 Conclusion: Non-invasive independent predictors for screening esophageal varices may decrease medical as well as financial burden, hence improving the management of cirrhotic patients. These predictors, however, need further work to validate reliability.