Background and Purpose
The gut microbial metabolite butyrate is linked to the modulation of metabolic disease. The mechanism by which butyrate effects in atherosclerosis is unknown. Hence, the present investigation into effects of butyrate on high‐fat diet‐fed ApoE−/− mice after 16 weeks' administration.
Experimental Approach
Gut microbiota composition was analysed via 16S rRNA gene sequencing of caecal contents. The effects of butyrate on atherosclerosis were evaluated in vivo using the ApoE−/− mice model. Serum lipids and glucose were analysed for physiological changes and differentially expressed genes in liver samples were identified by hepatic transcriptome profiling. The proteins involved in reverse cholesterol transport were quantified by Western blot and immunohistochemical staining. Finally, the up‐regulatory effects of butyrate on ATP‐binding cassette sub‐family A member 1 (ABCA1) were further evaluated in RAW 264.7 cells along with role of specificity protein 1 by inhibition and silencing.
Key Results
Oral gavage of butyrate altered microbiota composition and enhanced gut microbial diversity that was decreased by high fat diet (HFD). Butyrate treatment significantly inhibited the HFD‐induced atherosclerosis as well as hepatic steatosis without changing body weight gain in ApoE−/− mice. Butyrate had metabolic effects on the liver by regulation of gene expression involved in lipid/glucose metabolism. Furthermore, ABCA1 was significantly induced by butyrate in vivo, ex vivo and in vitro and Sp1 pathway was identified as a potential mechanism.
Conclusion and Implications
Butyrate ameliorates HFD‐induced atherosclerosis in ApoE−/− mice via ABCA1‐mediated cholesterol efflux in macrophages, which suggesting a promising therapeutic strategy for protecting against atherosclerosis.
Trimethylamine-N-oxide (TMAO), a derivative from the gut microbiota metabolite trimethylamine (TMA), has been identified to be an independent risk factor for promoting atherosclerosis. Evidences suggest that berberine (BBR) could be used to treat obesity, diabetes and atherosclerosis, however, its mechanism is not clear mainly because of its poor oral bioavailability. Here, we show that BBR attenuated TMA/TMAO production in the C57BL/6J and ApoE KO mice fed with choline-supplemented chow diet, and mitigated atherosclerotic lesion areas in ApoE KO mice. Inhibition of TMA/TMAO production by BBR-modulated gut microbiota was proved by a single-dose administration of d9-choline in vivo. Metagenomic analysis of cecal contents demonstrated that BBR altered gut microbiota composition, microbiome functionality, and cutC/cntA gene abundance. Furthermore, BBR was shown to inhibit choline-to-TMA conversion in TMA-producing bacteria in vitro and in gut microbial consortium from fecal samples of choline-fed mice and human volunteers, and the result was confirmed by transplantation of TMA-producing bacteria in mice. These results offer new insights into the mechanisms responsible for the anti-atherosclerosis effects of BBR, which inhibits commensal microbial TMA production via gut microbiota remodeling.
Three new glucosylated caffeoylquinic acid isomers (1–3), along with six known compounds, have been isolated from an aqueous extract of the flower buds of Lonicera japonica. Structures of the new compounds were determined by spectroscopic and chemical methods as (−)-4-O-(4-O-β-d-glucopyranosylcaffeoyl)quinic acid (1), (−)-3-O-(4-O-β-d-glucopyranosylcaffeoyl)quinic acid (2), and (−)-5-O-(4-O-β-d-glucopyranosylcaffeoyl)quinic acid (3), respectively. In the preliminary in vitro assays, two known compounds methyl caffeate and 2ʹ-O-methyladenosine showed inhibitory activity against Coxsackie virus B3 with IC50 values of 3.70 μmol/L and 6.41 μmol/L and SI values of 7.8 and 12.1, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.