Eugenol nanoparticle as a therapeutic agent against <i>Pseudomonas</i> infection in mice

We reported earlier about development of nano-formulation of an essential oil "eugenol" through its entrapment within animal protein "gelatin," using a simple ultrasonication technique, followed by purification via ultracentrifugation. The synthesized eugenol nanoparticle (ENP) exhibited promising antibacterial and antibiofilm activity on pathogenic strain Pseudomonas aeruginosa MTCC 2488 in vitro. Here, we report on in vivo therapeutic efficacy of ENP against Pseudomonas-administered lung infection, developed in BALB/c mice. Our findings revealed that ENP treatment significantly reduced bacterial burden in infected lung tissues and promoted recovery from infection-associated weight loss, hypothermia, and fluid accumulation in mice. In addition, histopathological and immunological studies showed that the elevated level of inflammatory cytokines TNF-α, IL-1β, MCP-1, GM-CSF, and IFN-γ in lung tissue, serum, and broncho-alveolar lavage (BAL) fluid of Pseudomonas-infected mice were considerably attenuated to almost normal level by ENP treatment. Notably, free eugenol had not so high antipseudomonal action as ENP.