| Congresso Brasileiro de Microbiologia 2023 | Resumo: 341-1 | ||||
Resumo:The latest report from the World Health Organization on tuberculosis (TB) indicates that it is one of the infectious diseases that causes the most deaths after SARS-CoV-2. Diagnosis and treatment of TB have been exacerbated by access restrictions and lockdowns in various parts of the world. In addition, the rate of recurrence has been growing at an accelerated pace, and it is possible that in the near future, TB will once again become the leading cause of death in the world caused by a single infectious agent. B1CTcu5 antimicrobial peptide (AMP) is a peptide amide isolated from the skin secretion of the Indian toad Clinotarsus curtipes, and it was first reported in 2020, showing initial MIC values of 12.5 μg/mL against Mycobacterium tuberculosis (MTB). The aim of this work was to generate a library of B1CTcu5 analogs and evaluate their activity against MTB, as well as their cyto- and genotoxicity. To this end, 34 analogs synthesized by Fmoc Solid-phase peptide synthesis were initially designed by replacing Cys15 and Cys21 with either Ala, Ser, and/or Lys, as well as detection of serine at the N-terminus and the original linear/cyclic peptide. The products were analyzed by LC/MS and purified (>95%) by reverse-phase HPLC. The activity against MTB was performed using the H37Rv, CF169 and CF110 strain in 7H9 broth supplemented at a 1 McFarland scale and read with resazurin after 7 days. Likewise, AMPs were tested in J774A.1 murine macrophage strains using concentrations of 106 cells x well adhered 24 h before incubation and read with resazurin after 24 h. AMES tests were performed to determine mutagenic potential with TA98, TA100, TA102, and TA97a of S. Typhimurium mutant strains. The results showed varied anti-MTB activity (1.07 - 31.87 μg/mL), neither cytotoxic nor mutagenic, with the most promising one being CRDK-s16 and -18G, which was even better than isoniazid (3 μg/mL). In conclusion, B1CTcu5 analogs show promise as a peptide-based therapy against susceptible and drug-resistant MTB. Palavras-chave: Antimicrobial peptides, Antimycobacterial resistance, Drug desing, Drug discovery, Mycobacterium tuberculosis Agência de fomento:The São Paulo Research Foundation - FAPESP Proc. number 2020/16573-3; 2021/14603-5; 2023/01664-1 | |||||