Sargassum pallidum (S. pallidum), a traditional Chinese herb, is a homology of medicine and food that is widely used daily. This study focused on the antioxidant activity and modulation of the gut microbiota by S. pallidum ethanol extract (SPEE). The results of component determination showed that SPEE contained flavonoids (0.398 g/100 g) and polyphenols (0.193 g/100 g). SPEE effectively eliminated 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl and superoxide radicals in vitro; reduced the reactive oxygen species (ROS) and malondialdehyde (MDA) contents; and increased the glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) enzymatic activities in UVB-irradiated HaCaT cells, which indicated its in vitro antioxidant activity. In addition, the healthy mice that received SPEE treatment presented a reduced spleen index and MDA content and increased GSH-Px enzymatic activity, which indicated its in vivo antioxidant activity. Furthermore, 16S rRNA gene sequencing of fecal samples revealed that SPEE modulated the gut microbiota in mice, decreasing the abundance of harmful bacteria such as Helicobacter while increasing the abundance of beneficial bacteria such as Bifidobacterium and Akkermansia. This study systematically confirmed the antioxidant activity of SPEE, clarified its ability to modulate the gut microbiota, and elucidated the relationship between its antioxidant activity and the gut microbiota, laying a foundation for in-depth research and wider application of S. pallidum in antioxidants.

The antioxidant activity of selenium-containing soybean peptides (SePPs) has been previously demonstrated, despite their limited absorption in the small intestine. This study investigates the antioxidant mechanism of a selenium-containing tetrapeptide, Ser-Phe-Gln-SeM (SFQSeM), identified from SePPs, with particular emphasis on its interaction with the intestinal microbiota and its role in modulating host antioxidant defenses. The effects of SFQSeM were evaluated in a D-galactose-induced oxidative stress model and an antibiotic-treated mouse model. SFQSeM supplementation significantly reduced the oxidative stress in D-galactose-treated mice. It also promoted the growth of beneficial bacteria and increased the levels of acetate, butyrate and lactate in the intestine (P < 0.05). In the antibiotic-treated mouse model, depletion of the intestinal microbiota significantly reduced hepatic glutathione peroxidase (GSH-Px) activity (26.6%) and glutathione peroxidase 1 (GPx-1) expression (48.77%) compared to normal mice supplemented with SFQSeM (P < 0.05). In contrast to Na₂SeO₃ and selenomethionine, SFQSeM effectively restored the diversity of the intestinal microbiota disrupted by antibiotics. Lactobacillus, Lachnospiraceae_NK4A136_group, and Muribaculaceae were identified as predominant bacteria in the SFQSeM group, and were strongly associated with increased hepatic GSH-Px activity and GPx-1 mRNA expression (P < 0.05). In conclusion, intestinal microbiota enhances the antioxidant efficacy of SFQSeM by modulating microbial composition, producing active metabolites, and converting SFQSeM into a bioactive form of selenium.

Artemisia argyi (A. argyi) is a Chinese herbal medicine with reported anti-inflammatory effects. In this study, the A. argyi was extracted with water and ethanol, and the concentrations of 35 flavonoids in A. argyi water extract (WE) and ethanol extract (EE) were measured via targeted metabolomics. The antioxidant and anti-inflammatory activities of both WE and EE were firstly explored in vitro via chemical assays and cellular experiment, respectively. Both WE and EE showed significant 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ·OH, and O2· radical scavenging ability in a dose-dependent manner, and reduced the levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-22 (IL-22) in lipopolysaccharide (LPS) induced RAW264.7 cell model. In addition, the in vivo anti-colitis activity of both extracts was investigated in dextran sulfate sodium (DSS)-induced colitis mice, and the underlying mechanisms were elucidated by 16S rDNA sequencing and targeted metabolomics. We found that both WE and EE relieved colitis in mice, characterized by decreased disease activity index, increased colon length, improved pathological changes in colon tissue, while EE showed better anti-colitis activity. In addition, both 16S rDNA sequencing and targeted bile acids metabolomics indicated EE modulated gut microbiota and specifically increased the abundance of lithocholic acid (LCA), which might contribute to intestinal barrier function improvement via up-regulating the expression of colonic farnesoid X receptor (FXR). In summary, this study identified the anti-colitis mechanism of A. argyi EE by modulating gut microbiota, facilitating the production of LCA, activating FXR and improving intestinal barrier function.

The global incidence of hyperuricemia (HUA) is gradually increasing, and HUA poses a severe threat to human health. Between 25% and 50% of HUA patients are not effectively treated with current clinical medications due to drug contraindications or severe adverse reactions. Therefore, novel safe and effective uric acid-lowering products are needed. Fucoidan is a naturally derived polysaccharide containing sulfate groups exclusively found in brown algae. Although there are reports on the anti-HUA effects of fucoidan, the simultaneous regulation of gut microbiota by anti-HUA still needs to be fully understood. In this study, potassium oxonate (PO) and hypoxanthine-induced HUA model mice were treated with 100, 200 and 400 mg/kg fucoidan (from Laminaria japonica) for 14 days. The levels associated with HUA were quantified using assay kits to assess fucoidan intervention. 16S rRNA gene sequencing was used to analyze the effects of fucoidan in mice with HUA. The results showed that fucoidan reduced serum uric acid and urea nitrogen levels in a dose-dependent manner, and serum creatinine levels in the 200 and 400 mg/kg fucoidan groups were similar to those in the control group. It decreased the expression of uric acid metabolic protein levels of xanthine oxidase (XOD), adenosine deaminase (ADA), and glucose transporter (GLUT9) and increased ATP binding cassette subfamily G member 2 (ABCG2) protein expression. 16S rRNA gene sequencing revealed that the richness (Chao and Ace indices) and diversity (Shannon and Simpson indices) of the gut microbiota in model mice decreased, whereas supplementation with fucoidan alleviated gut microbiota dysbiosis in HUA model mice, leading to a gradual approach of α-diversity and β-diversity towards the control mice. Additionally, fucoidan supplementation significantly increased the abundance of beneficial bacteria, which are negatively correlated with the HUA-associated phenotypes, reassuring the positive effects of fucoidan on gut health. This study proposed that fucoidan can be considered a potential candidate for preventing and treating HUA.

In recent years, the research of marine drugs has become a global hot spot, and marine traditional Chinese medicine (MTCM) is an important part of traditional Chinese medicine. To promote the development and application of MTCM, this review collected 10 kinds of MTCM from the Pharmacopoeia of the People's Republic of China, analyzed and expounded their pharmacological effects. The pharmacological effects of MTCM are mainly anti-inflammation, antioxidation and anticancer, and could be used for the treatment of diabetes, atherosclerosis and other diseases. Modern pharmacological studies have confirmed that the pharmacological effects of MTCM are consistent with those recorded in ancient books, Ostreae Concha and Laminaria Thallus, as MTCM, have been listed as medicinal and edible substances in China. However, MTCM is facing problems such as lack of quality standards and resource destruction. Therefore, it is necessary to summarize the pharmacological effects and use methods of MTCM, to provide reference for the application and resource development of MTCM.

Hyperuricemia, a metabolic disorder related to uric acid metabolism dysregulation, has become a common metabolic disease worldwide, due to changes in lifestyle and dietary structure. In recent years, owing to their high activity and few adverse effects, food-derived active peptides used as functional foods against hyperuricemia have attracted increasing attention. This article aims to focus on the challenge associated with peptide-specific preparation methods development, functional components identification, action mechanism(s) clarification, and bioavailability improvement. The current review proposed recent advances in producing the food-derived peptides with high anti-hyperuricemia activity by protein source screening and matched enzymatic hydrolysis condition adjusting, increased the knowledge about strategies to search antihyperuricemia peptides with definite structure, and emphasized the necessity of combining computer-aided approaches and activity evaluations. In addition, novel action mechanism mediated by gut microbiota was discussed, providing different insights from classical mechanism. Moreover, considering that little attention was paid previously on the structure-activity relationships of anti-hyperuricemia peptides, we collected the sequences from published studies and make a preliminary summary about the structure-activity relationships, which in turn provided guides for enzymatic hydrolysis optimization and bioavailability improvement. Hopefully, this article could promote the development, application and commercialization of food-derived anti-hyperuricemia peptides in the future.