Less polar ginsenosides have better protective effects on mice infected by Listeria monocytogenes

Natural Antimicrobials: A Reservoir to Contrast Listeria monocytogenes

Natural environments possess a reservoir of compounds exerting antimicrobial activity that are forms of defence for some organisms against others. Recently, they have become more and more attractive in the food sector due to the increasing demand for natural compounds that have the capacity to protect food from pathogenic microorganisms. Among foodborne pathogens, Listeria monocytogenes can contaminate food during production, distribution, or storage, and its presence is especially detected in fresh, raw food and ready-to-eat products. The interest in this microorganism is related to listeriosis, a severe disease with a high mortality rate that can occur after its ingestion. Starting from this premise, the present review aims to investigate plant extract and fermented plant matrices, as well as the compounds or mixtures of compounds produced during microbial fermentation processes that have anti-listeria activity.

Safety evaluation of rare ginsenosides of stems and leaves from American ginseng: 90-day exposure toxicity study combined with intestinal flora analysis and metabonomics in rats

Rare ginsenosides have already been widely applied in many fields, including health food and bio-medicine. The human being can expose to rare ginsenosides directly or indirectly increasingly. However, there are few studies on the safety assessment of rare ginsenoside mixtures. In the present study, the sub-chronic toxicity of rare ginsenosides for 90 days on SD rats was performed by combining the intestinal flora analysis and urine metabonomics aiming to illustrate the safety of long-term consumption of rare ginsenosides and the potential damage for liver and intestinal. 48 adult rats were divided into four groups: control (0 mg/kg), low-dose (60 mg/kg), medium-dose (200 mg/kg), and high-dose (600 mg/kg). Rats in the high-dose group showed inflammatory changes in their livers and intestines. The strong bactericidal effect of rare ginsenosides caused intestinal flora disorder and changed the structure of intestinal flora in rats, thus inducing intestinal damage in rats. In the high-dose group, levels of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and alkaline phosphatase (AKP) increased significantly. As a result of the high-dose treatment, certain metabolic pathways were altered, such as vitamin B6 metabolism, methionine metabolism, glutathione metabolism, and others. These results indicated that high doses of rare ginsenosides induced liver injury by affecting the above metabolic pathways. Rare ginsenosides with no observed adverse effect level (NOAEL) were below 200 mg/kg/day in vivo. Thus, this present study provides insight into the rational use of rare ginsenosides.

Fish Oil Ameliorates Vibrio parahaemolyticus Infection in Mice by Restoring Colonic Microbiota, Metabolic Profiles, and Immune Homeostasis

The effect of fish oil (FO) on colonic function, immunity, and microbiota was investigated in Vibrio parahaemolyticus (Vp)-infected C57BL/6J mice. Mice intragastrically presupplemented with FO (4.0 mg) significantly reduced Vp infection as evidenced by stabilizing body weight and reducing disease activity index score and immune organ ratios. FO minimized colonic pathological damage, strengthened the mucosal barrier, and sustained epithelial permeability by increasing epithelial crypt depth, goblet cell numbers, and tight junctions and inhibiting colonic collagen accumulation and fibrosis protein expression. Mechanistically, FO enhanced immunity by decreasing colonic CD³⁺ T cells, increasing CD⁴⁺ T cells, downregulating the TLR4 pathway, reducing interleukin-17 (IL-17) and tumor necrosis factor-α, and increasing immune cytokine IL-4 and interferon-γ levels. Additionally, FO maintained colonic microbiota eubiosis by improving microbial diversity and boosting Clostridium, Akkermansia, and Roseburia growth and their derived propionic acid and butyric acid levels. Collectively, FO alleviated Vp infection by enriching beneficial colonic microbiota and metabolites and restoring immune homeostasis.