Macrophage Activity under Hyperglycemia: A Study of the Effect of Resveratrol and 3H-1,2-Dithiole-3-thione on Potential Polarization.

Currently, research is focused on bioactive compounds with the potential to promote macrophage polarization with the aim of reducing the development of inflammatory-related diseases. However, the effect of bioactive compounds under oxidative-stress-induced hyperglycemia on macrophage polarization has been scarcely investigated. RAW 264.7 macrophages were incubated under standard (SG) or high glucose (HG) conditions and stimulated with lipopolysaccharide (LPS) (10, 60 and 100 ng/mL) to monitor macrophage polarization after resveratrol (RSV) or 3H-1,2-dithiole-3-thione (D3T) supplementation (2.5, 5, 10 and 20 µM). Under SG and HG conditions without LPS stimulation, RSV significantly decreased macrophage viability at the highest concentration (20 µM), whereas D3T had no or low effect. LPS stimulation at 60 and 100 ng/mL, under SG and HG conditions, increased significantly macrophage viability. Both RSV and D3T significantly decreased NO production in LPS-stimulated macrophages under HG condition, whereas only D3T increased GSH levels at 100 ng/mL and normalized MDA values at 60 ng/mL of LPS under HG condition. Under 60 ng/mL LPS stimulation and HG, mRNA IL-1 and IL-6 were higher. Interestingly, RSV decreased pro-inflammatory interleukins; meanwhile, D3T increased Arg1 and IL-10 relative expression. Overall, our results indicate that hyperglycemia plays a fundamental role in the modulation of macrophage-induced inflammation in response to bioactive compounds.