Synthesis of a novel polycerasoidol analogue with pan-PPAR agonism:
anti-inflammatory effects and improvement of metabolic derangements in
ob/ob mice
Abstract
Background and Purpose: Selective peroxisome proliferator-activated
receptors (PPARs) are widely used to treat metabolic complications;
however, the limited effect of PPARα agonists on glucose metabolism and
the adverse effects associated with selective PPARγ activators have
stimulated the development of novel pan-PPAR agonists to treat metabolic
disorders. Here, we synthesised a new prenylated benzopyran (BP-2) and
evaluated its PPAR-activating properties, anti-inflammatory effects and
impact on metabolic derangements. Experimental Approach: BP-2 was used
in transactivation assays to evaluate its agonism to PPARα, PPARβ/δ and
PPARγ. A parallel-plate flow chamber was employed to investigate its
effects on TNFα-induced leucocyte-endothelium interactions, and flow
cytometry and immunofluorescence were used to determine its effects on
the expression of endothelial cell adhesion molecules (CAMs) and
chemokines and p38-MAPK/NF-κB activation. PPARs/RXRα interactions were
determined using a gene silencing approach. Analysis of its impact on
metabolic abnormalities and inflammation was performed in ob/ob mice.
Key Results: BP-2 displayed strong PPARα activity, with moderate and
weak activity against PPARβ/δ and PPARγ activity, respectfully. In
vitro, BP-2 reduced TNFα-induced endothelial ICAM-1, VCAM-1 and
fractalkine/CX3CL1 expression, suppressed mononuclear cell arrest via
PPARβ/δ-RXRα interactions and decreased p38-MAPK/NF-κB activation. In
vivo, BP-2 improved the circulating levels of glucose and triglycerides
in ob/ob mice, suppressed T-lymphocyte/macrophage infiltration and
proinflammatory markers in the liver and white adipose tissue, but
increased the expression of the M2-like macrophage marker CD206.
Conclusion and Implications: BP-2 emerges as a novel pan-PPAR lead
candidate to normalise glycaemia/triglyceridaemia and minimise
inflammation in metabolic disorders, likely preventing the development
of further cardiovascular complications.