Anti-inflammatory and antioxidant properties of a new arylidene-thiazolidinedione in macrophages.

Thiazolidinediones (TZDs) are a class of drugs used for treatment of type 2 diabetes. However, the therapy with currently available TDZs (e.g. rosiglitazone) is associated with important side effects, such as edema and weight gain, suggesting that the investigation of alternative TZDs with better pharmacological properties is warranted. In this study, we investigated both anti-inflammatory and antioxidant properties of a new chemically modified TZD, the arylidene-thiazolidinedione 5-(4-methanesulfonyl-benzylidene)-3-(4-nitrobenzyl)-thiazolidine-2,4-dione (SF23), and compared the results to those obtained with rosiglitazone. We found that our SF23 displays a weaker affinity for PPARγ, up-regulating in a lower magnitude the expression of both PPARγ and CD36 compared to rosiglitazone. In lipopolysaccharide (LPS)-stimulated macrophages, SF23 decreased nitrite production and attenuated the mRNA expression of both iNOS and COX-2. These anti-inflammatory effects were comparable to those obtained with rosiglitazone. Interestingly, SF23, but not rosiglitazone, prevented LPS-induced mitochondrial membrane hyperpolarization, apoptosis, reactive oxygen species (ROS) generation, and the expression of NADPH oxidase subunits, Nox1 and Nox2. In addition, in macrophages from Nrf2⁻/⁻ mice, SF23 protected against LPSinduced cellular death and ROS production, whereas rosiglitazone was only able to protect normal Nrf2⁺/⁺ cells against oxidative injury, suggesting that, unlike rosiglitazone, the antioxidant activity of SF23 might be Nrf2-independent. Finally, in macrophages exposed to high concentrations of glucose, SF23 induced significant increases in the mRNA expression of glucose transporters, insulin receptor substrate and mitoNEET. Altogether, our data indicate that our new chemically modified TDZ displays similar anti-inflammatory properties, but superior antioxidant effects on the LPS-stimulated macrophages compared to rosiglitazone.

Anti-Inflammatory properties of a lipid fraction obtained from Sideritis javalambrensis.

A lipid fraction obtained by activity-guided fractionation from the hexane extract of Sideritis javalambrensis was evaluated for anti-inflammatory activity. This fraction significantly inhibited paw oedema induced by carrageenan as well as ear oedema induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in mice after oral or topical administration, respectively. Quantitation of the specific marker myeloperoxidase (MPO) demonstrated that its topical anti-inflammatory activity was associated with reduction in cell infiltration into inflamed tissues. The lipid fraction significantly decreased leukocyte granular enzyme release (beta-glucuronidase), but failed to inhibit superoxide generation. Histamine release from mast cells was also suppressed in a concentration-dependent manner. In addition, non-toxic concentrations of this fraction reduced nitric oxide (NO) generation in lipopolysaccharide (LPS)-treated J774 macrophages. Taken together, these results suggest that the lipid fraction exerts in vivo anti-inflammatory activity with the partial contribution of inhibitory actions on some inflammatory responses.