DOI: 10.5061/dryad.dz08kprzs
title: Astaxanthin from Haematococcus pluvialis prevents high-fat diet-induced hepatic steatosis and oxidative stress in mice by gut-liver axis modulating properties

description: Scope: Evidence is mounting that astaxanthin (ATX), a xanthophyll
 carotenoid, used as a nutritional supplement to prevent chronic metabolic
 diseases. The present study aims to identify the potential function of ATX
 supplementation in preventing steatohepatitis and hepatic oxidative stress
 in diet-induced obese mice. Methods and Results: In this study, ATX as
 dose of 0.25%, 0.5% and 0.75% have orally administered to mice along with
 a high-fat diet (HFD) to investigate the role of ATX in regulating liver
 lipid metabolism and gut microbiota. The study showed that ATX
 dose-dependently reduces body weight, lipid droplet formation, hepatic
 triglycerides and ameliorated hepatic steatosis and oxidative stress.
 0.75% ATX altered the levels of 34 lipid metabolites related to hepatic
 cholesterol and fatty acid metabolism which might be associated with
 downregulation of lipogenesis-related genes and upregulation of bile acid
 biosynthesis-related genes. The result also revealed that ATX alleviates
 HFD-induced gut microbiota dysbiosis by significantly inhibiting the
 growth of obesity-related Parabacteroides and Desulfovibrio while
 promoting the growth of Allobaculum and Akkermansia. Conclusion: The study
 results suggested that dietary ATX may prevent the development of hepatic
 steatosis and oxidative stress with the risk of metabolic disease by
 gut-liver axis modulating properties.
description: The body weight and food intake were
 recorded daily for 63 days. To avoid error values, the measurement of
 weight was repeated three times for each mouse. Total RNA was extracted from liver tissue
 using TRIzol reagent (Shenggong BBI Life, Shanghai, China) according to
 the manufacturer’s instructions. Then, cDNA was synthesized from total RNA
 using the PrimeScript Reverse Transcription reagent kit (Takara, Dalian,
 China). Quantitative PCR was conducted in triplicate for each group to
 detect gene expression. The quantitative analysis of
 <em>AMPK</em>, <em>SREBP1c</em>,
 <em>ACC</em>, <em>CPT-1</em>,
 <em>PPARα</em>, <em>PPARγ</em>,
 <em>LXRα</em>,<em> SCD-1</em>,
 <em>PGC-1</em>, <em>FAS</em>,<em>
 CYP27A1</em>, and <em>CYP7A1</em> mRNA expression in the
 liver was measured in triplicate for each group by quantitative PCR.
 According to the SYBR Premix Ex Taq II (Takara, Dalian, China), the
 thermal cycle of qPCR was reacted on the CFX 96 Real-Time PCR Detection
 system (BIO-RAD, Hercules, CA, USA) under the following conditions: 95 °C
 for 10 min, then 40 cycles of 95 °C for 15 s, 60 °C for 30 s, and 72 °C
 for 30 s. Table S2 (supplement files) shows the PCR primer sequences of
 each gene, and the target genes were normalized to the reference gene
 GAPDH. The 2<sup>−ΔΔCt </sup>method was used to calculate
 relative gene expression. The caecal contents were sent to Shanghai
 Personal Biotechnology Co., Ltd. to investigate microbial diversity
 through 16S rRNA analysis on the Illumina MiSeq platform. When the
 microbial DNA was isolated, polymerase chain reaction (PCR) of the V3-V4
 region of the bacterial 16S rRNA gene was performed using the forwards
 primer 5′-ACTCCTACGGGAGGCAGCA-3′ and the reverse primer
 5′-GGACTACHVGGGTWTCTAAT-3′ according to the manufacturer’s protocol
 (24-25). A previous study illustrated the
 analytical conditions and detailed parameters (18). All experiments were biologically repeated
 three times, and the data were analysed with Social Sciences (SPSS 16.0)
 statistical software and are presented as the mean ± SD. Multiple
 comparisons among treatments were statistically analysed using Duncan’s
 multiple range test in one-way analysis of variance (ANOVA) (<em>P
 &lt; 0.05</em>). Origin 9.1 was used to draw
 charts.
description: Please refer to ReadMe file.