The Antibacterial Effect of Carica papaya L. Extracts and Their Synergistic Effect with Antibiotic and Non-antibiotic Drugs

Aims: Antibacterial activity of Carica papaya leaf and seed extracts, their synergism with antibiotic and non-antibiotic drugs and GC-MS analysis of extracts.

Study Design: Antibacterial activity was evaluated by Disc and Well diffusion method. Synergism with antibiotic drug, Gentamicin, and non-antibiotic drug, Vitamin C, were done by disc diffusion method. GC-MS analysis carried out in GC-MS equipment (Thermo Scientific Co.).

Place and Duration of Study: Study was conducted in Department of Botany and Department of Chemistry, St. Thomas’ College, Thrissur between December 2015 to April 2016.

Methodology: We include 3 gram negative (E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and a gram positive (Staphylococcus aureus) bacteria in this study. Antibacterial activity of Carica papayaextracts (water, petroleum benzene, chloroform and ethanol extracts) against these bacteria’s were studied. Their synergisms with antibiotic as well as non antibiotic drugs were also evaluated. GC-MS analysis of all the extracts were also done.

Results: In the antibacterial activity assessment, all the four extracts of tender leaves were effective against E. coli than other plant materials. Seed extracts were more effective against P. aeruginosa and S. aureus. In synergistic analysis, water and ethanol extracts of all the plant materials have an enhanced effect with gentamicin against E. coli and P. aeruginosa. Yellow leaves extracts along with gentamicin exhibited an inhibition zone which is greater than that of gentamicin alone. Vitamin C gave enhanced activity against all the tested bacteria when combined with papaya extracts. GC-MS analysis proved that more number of bioactive components were present in petroleum benzene extract of tender leaves than all other extracts.

Conclusion: The results shows that Carica papaya extracts have antibacterial activity and when they were combined with antibiotic and non antibiotic drugs. In GC-MS analysis, tender leaves exhibited more bioactive components.