Antibacterial activities and phytochemical screening of crude extract of <i>Carica papaya</i> leaf against selected pathogens

Abstract

Carica papaya commonly known as paw paw belongs to the family of Curcubitaceae and commonly grown in tropical regions. It possesses  antimicrobial, antihelmintic and antioxidant properties. The study assessed the antibacterial potency of Carica papaya against Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. Acetone and aqueous extracts of the leaves of Carica papaya were obtained using standard methods. The antibacterial activity of the extracts was done using agar well diffusion methods. The Minimum inhibitory and Minimum bactericidal concentrations were done using standard procedures. The antibacterial activities of the crude extracts of Carica papaya against the test organisms revealed that acetone extract showed maximum zone of inhibition on Staphylococcus aureus with a diameter of 17.90±0.10mm at 500 mg/ml and the lowest inhibitory effect on Klebsiella pneumoniae with a zone of 6.50±0.50mm at 100 mg/ml, the aqueous extract showed maximum zone of  inhibition on Staphylococcus aureus with a diameter of 15.50±0.50mm at 500 mg/ml and the lowest zone of inhibition was on Staphylococcus aureus with a diameter of 6.50±0.50mm at 100 g/ml. The Minimum Inhibitory Concentration of acetone and aqueous extract was 40 mg/ml and 50mg/ml against Klebsiella pneumoniae respectively. The Minimum Bactericidal Concentration of the extracts ranges from 40-60mg/ml. The qualitative  phytochemical screening result revealed the presence of tannins, saponnin, alkaloids and steroid. The quantitative phytochemicals revealed 0.70%  of flavonoids, 0.48% of alkaloids, 1.02% of tannin, 0.11% of steroids and 1.08% of glycoside. The result obtained revealed that crude extracts of Carica papaya leaves has antibacterial activities against the test organisms.

Keywords: Carica papaya, Phytochemical screening, Pathogens, Antibacterial  activity