Aims: Agonists to the glucagon-like peptide 1 receptor (GLP1R) agonists and dual agonists targeting GLP1R and the glucagon receptor (GCGR) or the Glucose-dependent insulinotropic peptide receptor (GIPR) are currently being developed for the treatment of non-alcoholic steatohepatitis (NASH). We have tested specific mono-agonists to these three receptors individually and in combination in a mouse model of diet-induced NASH and fibrosis, to decipher the contribution of their activities and potential additive effects on improving systemic and hepatic metabolism.Materials and methods: Advanced NASH was induced by pre-feeding C57BL/6J mice a diet rich in fat, sucrose and cholesterol for 36 weeks. This was followed by eight weeks of treatment with the receptor-specific agonists 1-GCG (20 µg/kg bid sc), 2-GLP1 (3 µg/kg bid sc) or 3-GIP (30 µg/kg bid sc), or the dual (1+2) or triple (1+2+3) combinations thereof. A dual GLP1R/GCGR agonistic peptide, 4dual-GLP1/GCGR (30 µg/kg bid sc), and liraglutide (100 µg/kg bid sc) were included as references.Results: Whereas 1-GCG and 3-GIP alone, at the selected low dose, did not influence body weight, liver lipids and histology, their combination with 2-GLP1 provided additional weight loss, reduction in liver triglycerides and improvement in histological NAFLD activity score (NAS). In addition, there was a trend to further reduction in markers of hepatic inflammation and fibrosis. Notably, compared to high-dose liraglutide, 4-dual-GLP1R/GCG as well as the dual and triple combinations of selective mono-agonists demonstrated stronger improvement in NAS at the same extent of body weight loss.Conclusions: GCGR and GIPR agonism provide additional, body weight-independent improvement in a murine model of advanced NASH with fibrosis on top of GLP1R agonism.

ScopeAs a result of the obesity epidemic, the prevalence of non‐alcoholic steatohepatitis (NASH) is increasing. No drug is approved for the treatment of NASH. In this study, the effect of a nutritional supplement, Mastiha or Chios mastic gum, on metabolic and histological parameters and on the gut microbiome in mice with NASH and fibrosis was investigated.Methods and resultsAdvanced NASH was induced by feeding C57BL/6J mice a diet rich in fat, sucrose, and cholesterol for 41 weeks. After randomization, animals received the NASH‐inducing diet with or without 0.2% (w/w) Mastiha for a further 8 weeks. Disease activity was assessed by liver histology and determination of plasma transaminase activities. Fecal microbiota DNA extraction and 16S rRNA amplicon sequencing were used to determine the composition of the gut microbiome.Mastiha supplementation led to a significant reduction in circulating alanine aminotransferase (ALT) activity, improvement in hepatic steatosis and collagen content, and a reduction in NAFLD activity score. Furthermore, it resulted in a partial but significant recovery of gut microbiota diversity and changes in identity and abundance of specific taxa.ConclusionThis is the first study demonstrating an improvement in disease activity in mice with advanced NASH with fibrosis by a diet containing Mastiha.

Background and Purpose BK channels play important roles in various physiological and pathophysiological processes and thus have been the target of several drug development programmes focused on creating new efficacious BK channel openers, such as the GoSlo‐SR compounds. However, the effect of GoSlo‐SR compounds on vascular smooth muscle has not been studied. Therefore, we tested the hypothesis that GoSlo‐SR compounds dilate arteries exclusively by activating BK channels. Experimental Approach Experiments were performed on rat Gracilis muscle, saphenous, mesenteric and tail arteries using isobaric and isometric myography, sharp microelectrodes, digital droplet PCR and the patch‐clamp technique. Key Results GoSlo‐SR compounds dilated isobaric and relaxed and hyperpolarised isometric vessel preparations and their effects were abolished after (a) functionally eliminating K+ channels by pre‐constriction with 50 mM KCl or (b) blocking all K+ channels known to be expressed in vascular smooth muscle. However, these effects were not blocked when BK channels were inhibited. Surprisingly, the Kv7 channel inhibitor XE991 reduced their effects considerably, but neither Kv1 nor Kv2 channel blockers altered the inhibitory effects of GoSlo‐SR. However, the combined blockade of BK and Kv7 channels abolished the GoSlo‐SR‐induced relaxation. GoSlo‐SR compounds also activated Kv7.4 and Kv7.5 channels expressed in HEK 293 cells. Conclusion and Implications This study shows that GoSlo‐SR compounds are effective relaxants in vascular smooth muscle and mediate their effects by a combined activation of BK and Kv7.4/Kv7.5 channels. Activation of Kv1, Kv2 or Kv7.1 channels or other vasodilator pathways seems not to be involved.

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