Boswellia carteri extract and 3-O-acetyl-alpha-boswellic acid suppress T cell function

Fitoterapia. 2020 Oct;146:104694. doi: 10.1016/j.fitote.2020.104694. Epub 2020 Jul 24.

Abstract

Resins from various Boswellia species have a long track record in different cultures as a treatment for inflammatory diseases. This study was designed to provide evidence for the anti-inflammatory capacity and medicinal use of Boswellia carteri (Burseraceae). A dichloromethane (DCM) extract of B. carteri gum resin and isolated compounds thereof were immunologically characterized. Flow cytometric-based analysis was performed to investigate the impact of B. carteri extract on proliferation, viability, and function of anti-CD3 and anti-CD28 activated human primary T cells. The secretion level of IL-2 and IFN-γ was determined by a bead array-based flow cytometric technique. HPLC-based activity profiling of the B. carteri extract identified active compounds. The impact of B. carteri extract and isolated compounds on the IL-2 transcription factor activity was addressed using specially designed Jurkat reporter cells. The extract of B. carteri suppressed the proliferation of human primary T lymphocytes in vitro in a concentration-dependent manner, without inducing cytotoxicity. Thereby, the B. carteri extract further reduced the degranulation capacity and cytokine secretion of stimulated human T cells. Transcription factor analysis showed that the immunosuppressive effects of the extract are based on specific NFAT-conditioned suppression within T cell signaling. Through HPLC-based activity profiling of the extract, 3-O-acetyl-alpha-boswellic acid was identified as the compound responsible for the NFAT-based mechanism. The recent study presents a scientific base for the immunosuppressive effects of B. carteri gum resin extract including a mode-of-action via the NFAT-conditioned suppression of T lymphocyte proliferation. The immunosuppressive effects of 3-O-acetyl-alpha-boswellic acid are depicted for the first time.

Keywords: 3-O-acetyl-α-boswellic acid; Boswellia; Immunosuppression; Interleukin-2; NFAT; T cell signaling.

MeSH terms

  • Anti-Inflammatory Agents / isolation & purification
  • Anti-Inflammatory Agents / pharmacology*
  • Apoptosis
  • Boswellia / chemistry*
  • Cell Degranulation / drug effects
  • Cell Proliferation / drug effects
  • Cytokines / analysis
  • Humans
  • Immunosuppressive Agents / isolation & purification
  • Immunosuppressive Agents / pharmacology*
  • Jurkat Cells
  • Molecular Structure
  • Phytochemicals / isolation & purification
  • Phytochemicals / pharmacology
  • Plant Extracts / pharmacology*
  • Resins, Plant / pharmacology
  • T-Lymphocytes / drug effects*
  • Triterpenes / isolation & purification
  • Triterpenes / pharmacology*

Substances

  • Anti-Inflammatory Agents
  • Cytokines
  • Immunosuppressive Agents
  • Phytochemicals
  • Plant Extracts
  • Resins, Plant
  • Triterpenes
  • boswellic acid