Effects of 1H-1,2,3-Triazole Derivatives of 3-O-Acetyl-11-Keto-Beta-Boswellic Acid from Boswellia sacra Resin on T-Cell Proliferation and Activation.

Background: 3-O-acetyl-11-keto-β-boswellic acid (β-AKBA), a triterpene natural product, is one of the main natural products of Boswellia sacra resin (BSR) and has reported biological and immunomodulatory effects. 1H-1,2,3-triazole derivatives of β-AKBA (named 6a-6d) were synthesized from β-AKBA. The 1H-1,2,3-triazole compounds are also known to have a wide range of biological and pharmacological properties as demonstrated by in vitro and in vivo studies. This study aimed to investigate the effects of these 1H-1,2,3-triazole derivatives of β-AKBA on human T-cell proliferation and activation. Methods: PBMCs isolated from healthy donors were activated by anti-CD3/CD28 monoclonal antibodies in the presence of β-AKBA (1) or 1H-1,2,3-triazole derivatives of β-AKBA or DMSO controls. Results: We found that similar to the parent compound β-AKBA (1), derivatives 6a, 6b, and 6d significantly inhibited T-cell expansion/proliferation and reduced the levels of CD25 activation marker on CD4(+) and CD8(+) T cells without exerting significant cytotoxic effects on T-cell viability at a concentration of 25 µM. However, compound 6c further inhibited T-cell expansion/proliferation and CD25 expression, but had a significant cytotoxic effect on cell viability at similar concentrations of 25 µM. Conclusions: These findings demonstrate the immunoinhibitory effects of β-AKBA (1) and its corresponding triazole derivatives on T-cell proliferation and activation, highlighting the promising therapeutic potential of these compounds in T-cell-mediated diseases.