Antimycobacterial and anti-inflammatory activities of fractions and substances from Erythrina verna Vell focusing on dual severe TB treatment approach

An Acad Bras Cienc. 2022 Oct 7;94(3):e20211032. doi: 10.1590/0001-3765202220211032. eCollection 2022.

Abstract

Tuberculosis remains a major health problem worldwide. Drug-resistant and hypervirulent Mycobacterium tuberculosis (Mtb) strains can lead to a hyperinflammatory response and necrotic pathology in hyper-reactive individuals that require adjunctive treatment. Plant-derived substances have been investigated for TB treatment, among which flavonoids stand out. We evaluate the anti-Mtb, anti-inflammatory and cytotoxicity activities of fractions and substances 1, 2 and 3 isolated from Erythrina verna through a bioassay guided fractionation. Seven fractions (1, 3-5 and 7-9) obtained from dichloromethane E. verna extract inhibited NO production (IC50 ≤ 15 μg/mL) with none or poor cytotoxic effect, while the fractions 4 and 5 notably reduced TNF-a production. Fractions 4, 6 and 9 suppressed Mycobacterium growth with MIC50 ≤ 20 μg/mL. Fraction 4 was the most potent due to dual biological activities. Erythratidinone and alpinumisoflavone inhibited the growth of Mtb H37Rv and hypervirulent strain in bacterial cultures (MIC50 ≤ 20 μg/mL), with erythratidinone standing out in reducing intracellular growth of Mtb H37Rv (5.8 ± 1.1 μg/mL). Alpinumisoflavone and erythratidinone were capable of inhibiting NO and TNF-α production besides showing significant inhibitory effects against Mycobacterium tuberculosis strains with low toxicity in macrophages. Both substances are promising for further studies focusing on an anti-TB dual treatment approach.

MeSH terms

  • Anti-Inflammatory Agents / pharmacology
  • Antitubercular Agents / pharmacology
  • Erythrina*
  • Flavonoids / pharmacology
  • Humans
  • Methylene Chloride
  • Microbial Sensitivity Tests
  • Mycobacterium tuberculosis*
  • Plant Extracts / pharmacology
  • Tumor Necrosis Factor-alpha

Substances

  • Anti-Inflammatory Agents
  • Antitubercular Agents
  • Flavonoids
  • Plant Extracts
  • Tumor Necrosis Factor-alpha
  • Methylene Chloride