Inflammatory bowel disease (IBD) is becoming an increasingly serious health problem in humans and animals. Probiotics can inhibit the development of IBD. Due to the specificity of the strains, the function and mechanism of action of different strains are still unclear. Here, a DSS-induced colitis mouse model was utilized to investigate the ability and mechanism by which Lacticaseibacillus casei IB1 alleviates colitis. Treatment with L. casei IB1 improved DSS-induced colitis in mice, as indicated by increased body weight, colon length, and goblet cell numbers and decreased disease activity index (DAI), proinflammatory factor (TNF-α, IL-1β, and IL-6) levels, and histopathological scores after intake of IB1. IB1 supplementation also improved the expression of tight junction proteins and inhibited the activation of the MAPK and NF-κB signaling pathways to alleviate intestinal inflammation. In addition, IB1 rebalanced the intestinal microbial composition of colitis mice by increasing the abundance of Faecalibaculum and Alistipes and decreasing the abundance of Bacteroides and Escherichia_Shigella. In summary, L. casei IB1 showed great potential for relieving colitis by regulating the microbiota and restoring the epithelial barrier. It can be used as a potential probiotic for the prevention and treatment of UC in the future.

Background: This study aimed to investigate the role of ROS/MAPK signaling pathways and the effects of baicalin in LPS-induced inflammatory responses in mice and porcine intestinal epithelial cells (IPEC-J2). Methods: In vivo, 18 male C57BL/6J mice were randomly divided into three groups (n = 6): control, LPS (3.5 mg/kg LPS administered intraperitoneally [ip] on day 7), and baicalin (200 mg/kg orally for 7 days, with LPS ip on day 7). On day 8, mice were sacrificed, and jejunal tissues were collected for H&E staining. ROS levels in serum and cytokine protein expressions (TNF-α and IL-6) in the jejunum were measured via ELISA, while intestinal MAPK proteins were analyzed using Western blotting. In vitro, the study involved two experimental setups: NAC (a ROS scavenger) and baicalin. For the NAC experiment, IPEC-J2 cells were divided into three groups: control, LPS, and NAC. In the LPS group, cells were treated with LPS (40 μg/mL) for 1 h. In the NAC group, cells were pretreated with NAC prior to LPS exposure. For the baicalin experiment, IPEC-J2 cells were divided into five groups: control, LPS, and baicalin at low (10 μM), medium (20 μM), and high (40 μM) doses. Cells were pretreated with baicalin for 24 h before LPS exposure. ROS/LDH levels and cytokine expressions in the supernatant were determined via ELISA, and MAPK protein expressions were assessed using Western blotting. Results: In vivo, LPS-induced oxidative stress and inflammatory responses in the intestine, reduced the villus height-to-crypt ratio, and significantly increased protein expressions of p-ERK, p-P38, JNK, and p-JNK (p < 0.05). Baicalin treatment significantly inhibited serum ROS levels (p < 0.01), reduced jejunal cytokine expressions (TNF-α and IL-6, p < 0.05), improved intestinal structural damage, and decreased p-ERK, p-P38, and p-JNK protein expressions (p < 0.05). In vitro, NAC significantly reduced ROS levels (p < 0.01), cytokine expressions (TNF-α and IL-6), and MAPK activation (ERK, JNK, P38, and their phosphorylated forms, p < 0.05). Baicalin also significantly decreased ROS (p < 0.05), TNF-α (p < 0.05), IL-6 (p < 0.05), and MAPK protein expressions (ERK, p-ERK, and p-P38, p < 0.05). Molecular docking demonstrated that baicalin effectively bound to ERK and P38 proteins. Conclusions: Baicalin mitigated LPS-induced inflammatory responses via the ROS/p-ERK/p-P38 signaling pathway in vivo and in vitro.

The choice of carrier material is critical in the study of natural drug release preparations and glycosylated magnetic molecularly imprinted materials. The stiffness and softness of the carrier material affect the efficiency of drug release and the specificity of recognition. The dual adjustable aperture-ligand in molecularly imprinted polymers (MIPs) provides the possibility of individualized design for sustained release studies. In this study, a combination of paramagnetic Fe₃O₄ and carboxymethyl chitosan (CC) was used to enhance the imprinting effect and improve drug delivery. A combination of tetrahydrofuran and ethylene glycol was used as a binary porogen to prepare MIP-doped Fe₃O₄-grafted CC (SMCMIP). Salidroside serves as the template, methacrylic acid acts as the functional monomer, and ethylene glycol dimethacrylate (EGDMA) serves as the crosslinker. Scanning and transmission electron microscopy were used to observe the micromorphology of the microspheres. The structural and morphological parameters of the SMCMIP composites were measured, including the surface area and pore diameter distribution. In an in vitro study, we found that the SMCMIP composite had a sustained release property of 50% after 6 h of release time in comparison to the control SMCNIP. The total amounts of SMCMIP released at 25 °C and 37 °C were 77% and 86%, respectively. In vitro results showed that the release of SMCMIP followed Fickian kinetics, meaning that the rate of release is dependent on the concentration gradient, with diffusion coefficients ranging from 3.07 × 10⁻² cm²/s to 5.66 × 10⁻³ cm²/s. The results of cytotoxicity experiments showed that the SMCMIP composite did not have any harmful effects on cell growth. The survival rates of intestinal epithelial cells (IPEC-J2) were found to be above 98%. By using the SMCMIP composite, drugs may be delivered in a sustained manner, potentially leading to improved therapeutic outcomes and reduced side effects.