Book of Abstracts - New Frontiers 2022

Abstracts of oral presentations

GREEN TEA POLYPHENOL IMPROVES INFLAMMATORY PHENOTYPE OF PERIVASCULAR ADIPOSE TISSUE BY OXIDIZING HYDROGEN SULFIDE (H 2 S) TO POLYSULFIDES (H 2 Sn)

J. Beltowski

Department of Pathophysiology, Medical University, Lublin, Poland

Background: Perivascular adipose tissue (PVAT) produces vasodilating and anti-inflammatory factors. However, in obesity/metabolic syndrome PVAT phenotype changes to pro-inflammatory one. Recently, it has been demonstrated that green tea polyphenols such as (−) -epigallocatechin (EGC) oxidize the gasotransmitter hydrogen sulfide (H 2 S) to polysulfides (H 2 Sn); the important signaling molecules (Redox Biol 2020; 37:101731). We examined the effect of EGC on periaortic adipose tissue (PAT) phenotype in rats fed high fat diet (HFD). Methods. Rats were fed regular diet or HFD for 1 month as well as were treated or not with EGC (10 mg/kg/day). The expression of pro- and antinflammatory factors was measured in PAT by qRT-PCR. H 2 S and H 2 Sn levels in PAT were measured by electrochemical sensor. Results. Expression/secretion of leptin, resisting, TNF-alpha, IL-6 and MCP-1 was higher and adiponectin was lower in PAT of obese rats which was accompanied by increased H 2 S production. The H 2 S and H 2 Sn donors, Na 2 S and Na 2 S 4 , had pro- and anti-inflammatory effects on PAT, respectively. Administration of EGC in HFD rats reduced the expression of leptin, resistin, TNF-alpha, IL-6 and MCP-1 and increased the expression of adiponectin. In addition, EGC reduced M1 macrophage marker, inducible NO synthase (iNOS), and increased the expression of M2 markers, IL-10 and arginase-1. The effects of EGC were mimicked by Na2S4. EGC decreased H 2 S and increased H 2 Sn in PAT of obese rats. The similar results were observed ex vivo in EGC-treated PAT explants Conclusions. EGC has the anti-inflammatory effect on perivascular adipose tissue mediated by oxidation of H 2 S to H 2 Sn. This effect may contribute to anti-atherosclerotic properties of green tea polyphenols.

Keywords: perivascular adipose tissue, hydrogen sulfide, polysulfides, adipokines, green tea plyphenols

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