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Background and Purpose: IL‐1β produced by macrophages via the NOD‐, LRR‐ and pyrin domain‐containing 3 (NLRP3) inflammasome, mediates the inflammatory crosstalk between macrophages and adipocytes. In our previous study, (16S,20S,24R)‐12β‐acetoxy‐16,23‐epoxy‐24,25‐dihydroxy‐3β‐(β‐D‐xylopyranosyloxy)‐9,19‐cyclolanost‐22(23)‐ene (AEDC), a cycloartane triterpenoid isolated from Actaea vaginata (Ranunculaceae), was found to possess anti‐inflammatory effect on LPS‐treated RAW264.7 macrophages. This study was designed to investigate whether AEDC modulates macrophage–adipocyte crosstalk to alleviate adipose tissue inflammation. Experimental Approach The anti‐inflammatory effect of AEDC was evaluated on LPS plus ATP‐induced THP‐1 macrophages and C57BL/6J mice. The expression of autophagy‐related and NLRP3 inflammasome complex proteins was analysed by western blots, immunofluorescence staining and co‐immunoprecipitation. The pro‐inflammatory cytokines levels were determined by ELISA kits. The adipose tissue inflammation was evaluated by histological analysis and immunohistochemical staining. Key Results: AEDC (5 and 10 μM) activated autophagy, which in turn suppressed the NLRP3 inflammasome activation and IL‐1β secretion in THP‐1 macrophages. AEDC increased the expression of SIRT3 deacetylase and enhanced its deacetylating activity to reverse mitochondrial dysfunction and activate AMP‐activated protein kinase, which together induced autophagy. Moreover, AEDC (10 μM) attenuated macrophage conditioned medium‐induced inflammatory responses in adipocytes and blocked THP‐1 macrophages migration towards 3T3‐L1 adipocytes. In inflammation mice, AEDC (5 and 20 mg·kg−1) treatment reduced the levels of pro‐inflammatory cytokines in serum and epididymal adipose tissue and reduced macrophage infiltration to alleviate adipose tissue inflammation. Conclusion and Implications: AEDC attenuated the inflammatory crosstalk between macrophages and adipocytes through SIRT3‐autophagy‐mediated NLRP3 inflammasome inhibition, which might used for the treatment of adipose tissue inflammation‐related metabolic disorders. [ABSTRACT FROM AUTHOR]

Background and Purpose: Skeletal muscle is the predominant site for glucose disposal and fatty acid consumption. Emerging evidence indicates that the crosstalk between adipose tissue and skeletal muscle is critical in maintaining insulin sensitivity and lipid homeostasis. The current study was designed to investigate whether myricanol improves insulin sensitivity and alleviates adiposity through modulating skeletal muscle-adipose tissue crosstalk.Experimental Approach: The therapeutic effect of myricanol was evaluated on palmitic acid (PA)-treated C2C12 myotubes and high-fat diet (HFD)-fed mice. The crosstalk between myotubes and adipocytes was evaluated using Transwell assay. The cellular lipid content was examined by Nile red staining. The mitochondrial content was assessed by MitoTracker Green staining and citrate synthase activity, and the mitochondrial function was examined by Seahorse assay. Expression of mitochondria-related and insulin signalling pathway proteins was analysed by Western blot, and the irisin level was determined by elisa kit.Key Results: Myricanol increased mitochondrial quantity and function through activating AMP-activated protein kinase, resulting in reduced lipid accumulation and enhanced insulin-stimulated glucose uptake, in PA-treated C2C12 myotubes. Furthermore, myricanol stimulated irisin production and secretion from myotubes to reduce lipid content in 3T3-L1 adipocytes. In HFD-fed mice, myricanol treatment alleviated adiposity and insulin resistance through enhancing lipid utilization and irisin production in skeletal muscle and inducing browning of inguinal fat.Conclusions and Implications: Myricanol modulates skeletal muscle-adipose tissue crosstalk, to stimulate browning of adipose tissue and improve insulin sensitivity in skeletal muscle. Myricanol might be a potential candidate for treating insulin resistance and obesity. [ABSTRACT FROM AUTHOR]