Dehydrohispanolone Derivatives Attenuate the Inflammatory Response through the Modulation of Inflammasome Activation.

The NLRP3 inflammasome plays a critical role in inflammation-mediated human diseases and represents a promising drug target for novel anti-inflammatory therapies. Hispanolone is a labdane diterpenoid isolated from the aerial parts of species. This diterpenoid and some derivatives have demonstrated anti-inflammatory effects in classical inflammatory pathways. In the present study, a series of dehydrohispanolone derivatives (-) was synthesized, and their anti-inflammatory activities toward NLRP3 inflammasome activation were evaluated. The structures of the dehydrohispanolone analogues produced were elucidated by NMR spectroscopy and mass spectrometry. Four derivatives significantly inhibited IL-1β secretion, with and being the most active (IC = 18.7 and 13.8 μM, respectively). Analysis of IL-1β and caspase-1 expression revealed that the new diterpenoids and are selective inhibitors of the NLRP3 inflammasome, reinforcing the previously demonstrated anti-inflammatory properties of hispanolone derivatives.