Phytochemical and Antimicrobial Studies of the Crude Extracts of the Leaves of Carica papaya Linn (Pawpaw) and Psidium guajava Linn (Guava)

Abstract

Psidium Guajava (Guava) and Carica Papaya leaves which have some ethnomedicinal applications were investigated. Phytochemical screening of their leaves revealed the presence of flavonoids, saponins, terpenoids, steroids, tannins and glycosides. Antimicrobial screening of the crude ethanolic extracts showed activity against Staphylococcus aureus, Streptococcus faecalis, and Escherichia coli. The minimum inhibitory concentration (MIC) for P. gujava on the organism was found to be 5.00 mg/ml against S. aureus, E. coli and S. faecalis, while that of C. papaya leaves is 10.00 mg/ml against S. aureus, E. coli and 8.00 mg/ml against S. faecalis respectively. C. papaya ethanolic extract showed more active inhibition against S. aureus with mean zone inhibition of 9.54 ± 0.03.  P.   gujava ethanolic extract has more active inhibition against E. coli with antibacterial activity with mean zone of inhibition of 10.44±0.02 and S. faecalis with mean zone of inhibition of 6.72 ± 0.01 respectively.  This study showed that the leaves extract of these plants are good sources of bioactive compounds. Demonstration of antibacterial activity against the test isolates is an indication that there is possibility of sourcing alternative antibiotic substances in these plants for the production of newer antibacterial agents. These plants therefore, could be an important source of medicine for the treatment of various diseases.