Baicalin attenuates lipopolysaccharide-induced intestinal inflammatory injury via suppressing PARP1-mediated NF-κB and NLRP3 signalling pathway

The Mechanism of Baicalin in the Treatment of Mycoplasma Pneumoniae Pneumonia by Regulating NLRP3/Caspase-1 Signaling Pathway

OBJECTIVE

This study investigated the mechanism of baicalin (BIA) attenuating the inflammatory response and lung injury in mycoplasma pneumoniae pneumonia (MPP) mice.

METHODS

MPP mouse models were established and then treated with BIA, azithromycin, or NLRP3 inflammasome activator. Lung wet-to-dry weight (W/D) ratio were weighed. Serum levels of MP-IgM, C-reactive protein (CRP) and bronchoalveolar lavage fluid (BALF) protein were detected by kits, NLRP3/Caspase-1 pathway-related protein levels by Western blot, and IL-1β, IL-18, IL-6 and TNF-α levels by ELISA. HE staining was performed to detect lung injury.

RESULTS

MPP mice showed elevated mouse lung W/D ratio, upregulated serum MP-IgM and CRP levels and BALF protein, and enhanced IL-6 and TNF-α levels, which were reversed by BIA or azithromycin treatment, suggesting that BIA attenuated pulmonary inflammatory response in MPP mice. The lung tissue of MPP mice showed upregulated NLRP3, cleaved Caspase-1,Caspase-1, GSDMD-N and GSDMD levels and raised IL-1β and IL-18 levels, and changes were annulled by BIA or azithromycin treatment, suggesting that BIA inhibited the NLRP3/Caspase-1 pathway activation. NLRP3/Caspase-1 pathway activation partially abrogated the alleviative effect of BIA on the pulmonary inflammatory response of MPP mice.

CONCLUSION

BIA mitigates inflammatory response and lung injury in MPP mice by inhibiting NLRP3/Caspase-1 pathway activation.

Baicalin Relieves Glaesserella parasuis-Triggered Immunosuppression Through Polarization via MIF/CD74 Signaling Pathway in Piglets

Glaesserella parasuis (G. parasuis) infection is responsible for Glässer's disease in pigs. G. parasuis could trigger piglet immunosuppression, but the mechanism of inducing immunosuppression by G. parasuis remains unknown. Macrophage migration inhibitory factor (MIF)/CD74 axis has been shown to participate in inflammation response and immunosuppression, but the function of MIF/CD74 during immunosuppression elicited by G. parasuis has not been fully explored. This experiment explored the efficacy of baicalin on immunosuppression elicited by G. parasuis alleviation through regulating polarization via the MIF/CD74 signaling pathway. Our data indicated that baicalin reduced IL-1β, IL-6, IL-8, IL-18, TNF-α, and COX-2 expression, and regulated MIF/CD74 axis expression in the spleen. Immunohistochemistry analysis showed that baicalin enhanced CD74 protein levels in the spleen of piglets induced by G. parasuis. Baicalin regulated the PI3K/Akt/mTOR signaling pathway and RAF/MEK/ERK signaling activation, modified the expression of the autophagy-related proteins Beclin-1, P62, and LC3B, promoted M2 polarization to M1 polarization, and enhanced CD3, CD4, CD8, and TIM3 levels in the spleen of piglets elicited by G. parasuis. Our study reveals the important functions of the MIF/CD74 axis in G. parasuis-induced immunosuppression and may offer a new therapeutic method to control G. parasuis infection.

Flavonoids from Scutellaria baicalensis: Promising Alternatives for Enhancing Swine Production and Health

Concerns over vaccine safety, bacterial resistance, and drug residues have led to increased interest in plant extracts for improving swine nutrition and health. Scutellaria baicalensis Georgi, rich in four primary flavonoids-baicalin, baicalein, wogonoside, and wogonin-demonstrates significant pharmacological properties, including anti-inflammatory, antioxidant, antibacterial, and antiviral activities in swine. These flavonoids have been shown to enhance growth performance, improve immunity, modulate gut microbiota, and aid in the prevention and treatment of various diseases. This review highlights the pharmacological effects of these flavonoids in swine, with a focus on network pharmacology to reveal the underlying molecular mechanisms. By constructing drug-target networks and identifying key signaling pathways, the review reveals how these flavonoids interact with biological systems to promote health. Furthermore, it discusses the practical applications of Scutellaria baicalensis flavonoids in swine production and outlines potential future research directions. This work provides a theoretical framework for understanding the therapeutic targets of these flavonoids, offering valuable insights for advancing sustainable and healthy pig farming practices.

Oxygen-supplying nanotherapeutics for bacterial septic arthritis via hypoxia-relief-enhanced antimicrobial and anti-inflammatory phototherapy

Bacterial septic arthritis, an inflammatory disease caused by bacterial infections, is often accompanied by the emergence of multidrug-resistant bacteria, making therapeutic treatment a formidable challenge. With the emergence of antibiotic resistance, research on antimicrobial photodynamic therapy (aPDT) has regained attention. However, insufficient singlet oxygen production due to the hypoxia in the infection microenvironment is recognized as a key limiting the efficacy of aPDT. Hence, in this study, we designed a bacteria-targeted liposomal nanoplatform (MCPL) to alleviate hypoxia in the infectious microenvironment and enhance aPDT for bacterial septic arthritis. The nanoplatform was developed by integrating the phototherapeutic agent CyI and small-sized Pt NPs into thermosensitive liposomes, with modification of maltohexose on the liposome surface. In vitro and in vivo studies showed that MCPL could specifically target bacterial cell membranes and be thermally activated to catalytically convert endogenous hydrogen peroxide (H2O2) in the septic joint, supplementing local O2 reservoirs. This, in turn, supplies additional substrate pools for photodynamic conversion into reactive oxygen species (ROS) with bacterial toxicity. Furthermore, the antibacterial mechanism revealed that MCPL can regulate the HIF-1α and NF-κB signaling pathways in immune cells, acting as an effective modulator of antioxidant and anti-inflammatory pathways in both macrophages and neutrophils. This study demonstrates that MCPL could not induce bacterial multidrug resistance and provide as an innovative approach for treating bacterial septic arthritis.

The Role of Necroptosis, Pyroptosis, and Ferroptosis in Porcine Intestinal Injury and Their Regulation by Nutrients and Bioactive Substances

In the early stages of development, piglets exhibit immature intestinal morphology and function, rendering them susceptible to a range of internal and external stressors, such as viral and bacterial infection, and mycotoxin exposure, which causes intestinal damage. The intestinal damage is characterized by various types of cell death within intestinal epithelium. The traditional cell death types have been categorized as necrosis, apoptosis, and autophagy. However, recent research has identified several forms of novel regulated cell death (RCD) such as necroptosis, pyroptosis, and ferroptosis. A growing body of evidence has underscored the pivotal role of necroptosis, pyroptosis, and ferroptosis in intestinal damage in pigs. Moreover, intervention strategies have been shown to mitigate these 3 RCDs when pigs are exposed to excessive adverse factors. This review aims to elucidate the role of these emerging RCDs in intestinal damage and summarize current understanding of their regulation by nutrients and bioactive substances in pigs. Our goal was to provide future intervention strategies designed to alleviate intestinal damage in pigs.

Baicalin and probenecid protect against Glaesserella parasuis challenge in a piglet model

Glaesserella parasuis (G. parasuis) induces vascular damage and systemic inflammation. However, the mechanism by which it causes vascular damage is currently unclear. Baicalin has important anti-inflammatory, antibacterial and immunomodulatory functions. In this study, we explored the ability of baicalin and probenecid to protect against G. parasuis challenge in a piglet model. Sixty piglets were randomly divided into a control group; an infection group; a probenecid group; and 25 mg/kg, 50 mg/kg and 100 mg/kg baicalin groups. The probenecid group and the 25 mg/kg, 50 mg/kg and 100 mg/kg baicalin groups were injected intramuscularly with 20 mg/kg body weight (BW) probenecid and 25 mg/kg BW, 50 mg/kg BW and 100 mg/kg BW baicalin, respectively. All piglets except those from the control group were injected intraperitoneally with 1 × 108 CFU of G. parasuis. The control group was injected intraperitoneally with TSB. The results showed baicalin and probenecid protected piglets against G. parasuis challenge, improved body weight and decreased temperature changes in piglets. Baicalin and probenecid attenuated IL-1β, IL-10, IL-18, TNF-α and IFN-γ mRNA levels in the blood for 48 h, inhibited the production of the nucleosides ATP, ADP, AMP and UMP from 24 to 72 h, reduced Panx-1/P2Y6/P2X7 expression, weakened NF-kB, AP-1, NLRP3/Caspase-1 and ROCK/MLCK/MLC signalling activation, and upregulated VE-cadherin expression in the blood vessels of piglets challenged with G. parasuis. Baicalin and probenecid alleviated pathological tissue damage in piglets induced by G. parasuis. Our results might provide a promising strategy to control and treat G. parasuis infection in the clinical setting.