Shauroseni Palchoudhuri
Herbicure Healthcare Bio-Herbal Research Foundation, India
Title: In-vitro and In-vivo analyses of an antidepressant compound as a highly potent antimicrobial agent
Biography
Biography: Shauroseni Palchoudhuri
Abstract
Statement of the problem: According to the World Health Organization infectious diseases cause almost 50% of all deaths in both developed and developing countries due to the emergence of multi-drug resistant pathogens. Although new antibiotics are being reported, the speedy appearance of mutations and acquisition of drug resistance plasmids restrict their usage. However, based on the property of multiplicity of actions in drugs, several researchers have evaluated the significant antimicrobial property in drugs belonging to different pharmacological classes. These have been designated as “nonantibiotics”. Intensive studies reveal that the phenothiazine group of chemotherapeutics, possessing three benzene rings along with a halogen moiety in their chemical structure, is the most active class of non-antibiotics. The present study describes a detailed investigation of antimicrobial action of the antidepressant drug doxepin which bears a close structural relationship with a phenothiazine.
Methodology: Minimum Inhibitory Concentration (MIC) of doxepin was determined against 250 strains of grampositive and gram-negative bacteria following international standard guidelines. Tests for synergism were performed between this antidepressant and known antibiotics by disc diffusion method. For in-vivo tests, doxepin was injected intraperitoneally into albino mice at different concentrations and challenged with virulent pathogen Salmonella enterica Serovar Typhimurium.
Findings: Staphylococci and Vibrios were highly sensitive to the drug, following moderate sensitivity in salmonellae and shigellae. Doxepin exhibited effective synergism with chloramphenicol and tetracycline and it is confirmed with the fractional inhibitory concentration index of 0.5 and 0.375 of the respective duo. Doxepin also manifested significant protection to the challenged mice (P<0.001) and potentially reduced the infection in internal organs.
Conclusion & Significance: Thus, the present study suggests that doxepin has the potential for being developed into a powerful antibacterial agent, the efficacy of which may be enhanced further with a suitable synergistic combination.