Icariin Ameliorates Exercise-Induced Acute Muscle Injury and Inflammation by Regulating the Expression of NF-κB and...

Icariin (ICA) is a flavonoid, that has been shown to exert antioxidant and anti-inflammatory effects. We aimed to explore the effects of acute exhaustive exercise on skeletal muscle injury and inflammatory factor levels, and investigate the anti-injury and anti-inflammatory effects of ICA through gut microbiota modulation.

Thirty C57BL/6J mice were administered ICA by gavage for 8 consecutive weeks, which were randomly divided into 3 groups as follows: solvent gavage control group (CON), 25 mg/kg ICA gavage group (ICA-L), and 50 mg/kg ICA gavage group (ICA-H). Serum biochemical and skeletal muscle antioxidant indicators were measured. Antioxidant enzyme activities and anti-inflammatory factor levels were determined. Additionally, gut microbiota were sequenced and analyzed by 16S rDNA and the correlations between metabolic indices and microbial species were assessed using Spearman correlation analysis.

ICA alleviated oxidative stress in skeletal muscle by reducing malondialdehyde (MDA) levels and upregulating the activities and mRNA expression of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX)). In addition, ICA suppressed inflammation through downregulation of tumor necrosis factor (TNF-α), nuclear factor-κB (NF-κB), and inflammatory cytokines (interleukin-6 (IL-6) and interleukin-1β (IL-1β)). Gut microbiota analysis revealed ICA enriched short-chain fatty acid (SCFA)-producing bacteria while inhibiting pathogens, with microbial shifts significantly correlated with muscle injury and antioxidant parameters, including Lachnospiraceae_NK4A136_group, Mucispirillum, and Harryflintia.

Our study demonstrated that ICA ameliorated exercise-induced acute muscle injury and inflammation in mice by modulating gut microbiota composition and regulating NF-κB signaling pathway along with related antioxidant enzyme gene expression.