Natural products from Vitex polygama and their antimycobacterial and anti-inflammatory activity

Abstract

Tuberculosis (TB) remains a worldwide public health threat because of the emergence of resistant strains and subsequent inappropriate response to current therapy. We have been studying the restinga plants’ antimycobacterial and anti-inflammatory potential. Dichloromethane fraction (DCM) from Vitex polygama Cham. showed high activity against Mycobacterium tuberculosis (Mtb) H37Rv. In this context, DCM fraction and isolated compounds were investigated against Mtb H37Rv and M299 (MDR strain) and for their immunomodulatory and cytotoxicity actions. Orientin showed the best antimycobacterial effect against Mtb M299 MDR strain (MIC₅₀ 15.4 ± 1.6 µg/mL), capacity of inhibiting NO production by macrophages (IC₅₀ 6.5 ± 1.2 µg/mL) and no significant cytotoxicity. The antimycobacterial effect of orientin was also observed on Mtb H37Rv intracellular growth in RAW 264.7 macrophages (MIC₅₀ 3.5 ± 1.1 and MIC₉₀ 9.1 ± 1.0 µg/mL). This is the first report describing the antimycobacterial effect of orientin, in both extra- and intracellular growth.

Keywords:

• Vitex polygama
• orientin
• isoorientin
• 20-hydroxyecdysone
• tuberculosis
• anti-inflammatory

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This study was financed in part by the Coordination of Superior Level Staff Improvement (CAPES), National Council for Scientific and Technological Development (CNPq) and Carlos Chagas Filho Research Support Foundation of the State of Rio de Janeiro (FAPERJ).