AUTHOR=Fattori Victor , Zarpelon Ana C. , Staurengo-Ferrari Larissa , Borghi Sergio M. , Zaninelli Tiago H. , Da Costa Fernando B. , Alves-Filho Jose C. , Cunha Thiago M. , Cunha Fernando Q. , Casagrande Rubia , Arakawa Nilton S. , Verri Waldiceu A. TITLE=Budlein A, a Sesquiterpene Lactone From Viguiera robusta, Alleviates Pain and Inflammation in a Model of Acute Gout Arthritis in Mice JOURNAL=Frontiers in Pharmacology VOLUME=9 YEAR=2018 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2018.01076 DOI=10.3389/fphar.2018.01076 ISSN=1663-9812 ABSTRACT=

Background: Gout is the most common inflammatory arthritis worldwide. It is a painful inflammatory disease induced by the deposition of monosodium urate (MSU) crystals in the joints and peri-articular tissues. Sesquiterpene lactones (SLs) are secondary metabolite biosynthesized mainly by species from the family Asteraceae. It has been demonstrated that SLs present anti-inflammatory, analgesic, antitumoral, antiparasitic, and antimicrobial activities. In this study, we aimed at evaluating the efficacy of the SL budlein A in a model of acute gout arthritis in mice.

Methods: Experiments were conducted in male Swiss or male LysM-eGFP mice. Animals were treated with budlein A (1 or 10 mg/kg) or vehicle 30 min before stimulus with MSU (100 μg/10 μL, intra-articular). Knee joint withdrawal threshold and edema were evaluated using electronic von Frey and caliper, respectively, 1–15 h after MSU injection. Leukocyte recruitment was determined by counting cells (Neubauer chamber), H&E staining, and using LysM-eGFP mice by confocal microscopy. Inflammasome components, Il-1β, and Tnf-α mRNA expression were determined by RT-qPCR. IL-1β and TNF-α production (in vitro) and NF-κB activation (in vitro and in vivo) were evaluated by ELISA. In vitro analysis using LPS-primed bone marrow-derived macrophages (BMDMs) was performed 5 h after stimulation with MSU crystals. For these experiments, BMDMs were either treated or pre-treated with budlein A at concentrations of 1, 3, or 10 μg/mL.

Results: We demonstrated that budlein A reduced mechanical hypersensitivity and knee joint edema. Moreover, it reduced neutrophil recruitment, phagocytosis of MSU crystals by neutrophils, and Il-1β and Tnf-α mRNA expression in the knee joint. In vitro, budlein A decreased TNF-α production, which might be related to the inhibition of NF-κB activation. Furthermore, budlein A also reduced the IL-1β maturation, possibly by targeting inflammasome assembly in macrophages.

Conclusion: Budlein A reduced pain and inflammation in a model of acute gout arthritis in mice. Therefore, it is likely that molecules with the ability of targeting NF-κB activation and inflammasome assembly, such as budlein A, are interesting approaches to treat gout flares.