EVALUATION OF Bacteriocin Leishmanicide Potential
Name: DIVAN HENRIQUE FERNANDES BARCELOS
Publication date: 21/03/2018
Advisor:
Name |
Role |
|---|---|
| DANIEL CLAUDIO DE OLIVEIRA GOMES | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| DANIEL CLAUDIO DE OLIVEIRA GOMES | Advisor * |
| PATRICIA MACHADO BUENO FERNANDES (M/D) | Internal Examiner * |
Summary: Leishmaniasis is a serious public health problem in Brazil and worldwide, with 12 million people infected. Available but efficient treatments present problems such as toxicity, high cost or parasite resistance. Bacteria are antimicrobial peptides produced in the ribosome by various bacteria. Its in vitro inhibition action has already been tested against fungi, bacteria and protozoa and, therefore, is considered as a substance with great biotechnological potential. The objective of this study was to evaluate the anti-leishmania capacity of bacteriocins A53; C55 and Nisin and BLIS P16, against the species of Leishmania infantum and Leishmania amazonensis. The results of IC50 for L. amazonensis were: A53 24,78 μg/mL; C55- 75,49 μg/ml and Nisin - 3191 μg/mL. Already for the treatment against promastigotes of L. infantum IC50 of: A53 12,57 μg/mL; C55 44,31 μg/mL. Nisin- 317,2 μg/mL and P16 - 2,9 μg/mL. Treatment against amastigotes of L. infantum was more efficient than against promastigotes, with an IC50 of 2,17 μg/mL for A53 and 1,76 μg/mL for P16. The cytotoxic action of A53 and P16 on macrophages of the J774A.1 lineage was also evaluated, presenting respectively IC50 of 9.75 μg/mL and 6.6 μg/mL. To evaluate the interaction between A53 and P16 with the external membrane of L. infantum promastigotes, scanning electron microscopy was performed, which demonstrated that the tested substances have the capacity to alter the external morphology of the parasite. Experiments were performed to evaluate the ability of P16 treatment to induce oxidative stress in promastigotes of L. infantum. The ability to stimulate apoptosis in promastigote forms has been verified, as well as a stimulus for overproduction of reactive oxygen species (ROS) and interference in cell cycle progression. The data of the present study demonstrate that the bacteriocins are promising for tests aimed at the development of new drugs against leishmaniasis.
