Potencial da Lectina CFL (Cratylia argentea) como adjuvante terapêutico em camundongos infectados com Listeria monocytogenes

Abstract

Infectious diseases caused by antibiotic-resistant microorganisms are among the main causes of mortality in the world, constantly generating the need for new treatments. CFL lectin (Cratylia argentea) is capable of modulating the immune system response and presents itself as a potential herbal product. In this study, this potential was evaluated in a model of bacterial infection caused by Listeria monocytogenes, which causes listeriosis, a disease that represents a high risk to public health and to the economy. For this, 32 mice were used. The animals in the experimental group were infected intraperitoneally with a bacterial suspension at 1 x 107 CFU / mL and, after 30 minutes, treated with CFL intravenously at dosages of 0.1 or 10 mg / kg. As control, untreated and uninfected animals were used. After 24 hours, the animals were euthanized. Then, the number of Colony Forming Units (CFU) in the spleen, liver, lung, peritoneal fluid, blood and intraperitoneal macrophages of the animals was quantified; total and differential counts of leukocytes circulating in blood and peritoneal fluid were performed; damage to organ tissues was analyzed using histopathology; RNA from spleen was extracted to analyze the gene expression of the cytokines IL-1β, IL-6, IL-10 and TNF-α and the enzyme iNOS; and the direct antimicrobial effect of lectin CFL against L. monocytogenes in vitro was evaluated. As a result, an increase in the average weight of the spleen and lung of the infected animals was observed, but this was prevented by treatment with CFL (10 mg / kg), while CFL (0.1 mg / kg) was able to prevent the increase in liver. CFL at 10 mg / kg reduced the bacterial load in the spleen, liver, blood and intraperitoneal macrophages of infected animals. There were no differences in the total leukocyte count in blood and peritoneal fluid between animal groups. The number of neutrophils, lymphocytes, monocytes and eosinophils did not change in the peritoneal fluid of animals treated with the lectin. No significant difference was found in cytokine gene expression, but animals infected and treated with CFL at 10 mg / kg had an increase in iNOS expression. The results suggest that CFL lectin has potential as a therapeutic adjuvant against intracellular bacterial infections caused by L. monocytogenes.