Guiqiu Hu

Mastitis causes oxidative stress, inflammation, mitochondrial dysfunction, and impaired lactation in dairy cows. This study investigated whether FUNDC1 (FUN14 domain-containing protein 1)-associated mitochondrial quality control protects mammary tissue from oxidative stress-driven senescence and whether cinnamon polysaccharide (CP) can restore this pathway during mastitis recovery. Mastitis-associated oxidative stress reduced FUNDC1 expression, disrupted mitochondrial dynamics by suppressing fusion and promoting fission, decreased mitochondrial membrane potential, and increased senescence markers in bovine mammary epithelial cells. FUNDC1 overexpression alleviated mitochondrial dysfunction and senescence-associated changes. Mechanistically, the E3 ubiquitin ligase FANCL contributed to the proteasome-dependent reduction of FUNDC1 under oxidative stress. CP treatment restored FUNDC1 expression, reduced inflammation and oxidative stress, improved mitochondrial homeostasis, and enhanced postmastitis milk-yield recovery when combined with antibiotic treatment. These findings identify the FANCL–FUNDC1 axis as a link between oxidative stress and mammary gland senescence and support CP as a functional adjunct for mastitis management.

The impairment of the blood-milk barrier (BMB) during mastitis severely compromises breastfeeding efficacy, highlighting an urgent need for effective nonantibiotic interventions. Natural anti-inflammatory and traditional Chinese medicine (TCM) compounds have thus garnered increasing attention as promising alternatives. Neohesperidin (Neo), a major bioactive flavonoid derived from the TCM herbs such as Citrus aurantium and its related species, has been historically associated with heat-clearing and detoxifying properties in TCM theory. However, its role in mastitis remains unclear. Herein, we investigated the protective effects of Neo on BMB integrity using an LPS-induced mastitis model. Our results demonstrate that Neo significantly alleviates mammary tissue damage and preserves BMB function. Further mechanistic studies indicate that Neo attenuates LPS-induced inflammatory responses and oxidative stress in mammary epithelial cells by inhibiting the TLR4/NF-κB pathway and concurrently activating the AMPK/Nrf2/HO-1 axis. Additionally, 16S rRNA sequencing and fecal microbiota transplantation (FMT) experiments demonstrated that Neo alleviates mastitis by modulating the gut microbiota (increasing beneficial bacteria and reducing harmful bacteria). In summary, this study confirms that Neo can mitigate mastitis and protect BMB function through its anti-inflammatory, antioxidant, and microbiota-regulating effects. The research not only elucidates the molecular mechanisms by which Neo exerts its mammary protective effects through inflammation-oxidative stress-gut microbiota but also provides new insights for the prevention and treatment of mastitis.

Bovine mastitis is a major challenge in the dairy industry, leading to persistent oxidative stress and mammary epithelial cell senescence, which impairs mammary gland function and hinders milk yield recovery. The mitochondria-associated membrane (MAM), a critical interface between mitochondria and the endoplasmic reticulum, plays an important role in redox balance and mitochondrial homeostasis. This study aimed to investigate the role of MAM in oxidative stress-induced cellular senescence in lactating Holstein dairy cows. We first examined oxidative stress markers and key proteins related to the MAM pathway in mammary tissues using Western blotting and commercial assay kits, and found that MAM pathway alterations were negatively correlated with oxidative stress. Transcriptome analysis further confirmed this association, with differentially expressed genes enriched in the mitochondria-endoplasmic reticulum network. Subsequently, an H₂O₂-induced oxidative stress model was established in bovine mammary epithelial cells. The results showed that oxidative stress inhibited MAM formation, promoted mitochondrial fission, and induced cellular senescence. In our previous experiments, we identified mitofusin 2 (MFN2) as a critical regulator in this process. Adenoviral overexpression of MFN2 enhanced MAM formation, alleviated oxidative stress, and delayed senescence. Further investigations revealed that MFN2 undergoes proteasomal degradation under oxidative stress. When the MAM structure was disrupted, MFN2 lost its antioxidative and antisenescence functions, indicating that MAM is essential for its activity. Based on this mechanism, we identified Gracilaria lemaneiformis polysaccharide (GLP) as a potential MFN2 activator. The GLP was found to upregulate MFN2 transcription, inhibit its ubiquitination, and enhance its protein stability. When combined with antibiotic therapy, GLP effectively reduced oxidative stress in mastitic cows, restored mammary gland function, and downregulated the expression of senescence-related markers. These findings suggest that oxidative stress-induced degradation of MFN2 impairs MAM formation, resulting in excessive mitochondrial fission and cellular senescence. Mitofusin 2 overexpression restores MAM integrity and mitigates oxidative stress. Activation of MFN2 by GLP offers a promising therapeutic strategy for mastitis, with potential to reduce recurrence and improve mammary gland health in dairy cows.

Flavonoid natural products are emerging as a promising approach for treating Ulcerative Colitis (UC) due to their natural origin and minimal toxicity. This study investigates the effects of Neohesperidin (NEO), a natural flavonoid, on Dextran Sodium Sulfate (DSS)-induced UC in mice, focusing on the underlying molecular mechanisms. Early intervention with NEO (25 and 50 mg/kg) mitigated colon shortening, restored damaged barrier proteins, and significantly reduced the inflammatory cytokine levels. Moreover, NEO inhibited the MAPK/NF-κB signaling pathway and enhanced the levels of intestinal barrier proteins (Claudin-3 and ZO-1). Additionally, NEO increased beneficial intestinal probiotics (S24-7 and Lactobacillaceae) while reducing harmful bacteria (Erysipelotrichi, Enterobacteriaceae). Fecal microbial transplantation (FMT) results demonstrated that NEO (50 mg/kg) markedly improved UC symptoms. In conclusion, early NEO intervention may alleviate DSS-induced UC by inhibiting inflammatory responses, preserving intestinal barrier integrity and modulating gut microbiota.

Inflammatory bowel disease (IBD) refers to a cluster of intractable gastrointestinal disorders with an undetermined etiology and a lack of effective therapeutic agents. Amygdalin (Amy) is a glycoside extracted from the seeds of apricot and other Rosaceae plants and it exhibits a wide range of pharmacological properties. Here, the effects and mechanisms of Amy on colitis were examined via 16S rRNA sequencing, ELISA, transmission electron microscopy, Western blot, and immunofluorescence. The results showed that Amy administration remarkably attenuated the signs of colitis (reduced body weight, increased disease activity index, and shortened colon length) and histopathological damage in dextran sodium sulfate (DSS)-challenged mice. Further studies revealed that Amy administration significantly diminished DSS-triggered gut barrier dysfunction by lowering pro-inflammatory mediator levels, inhibiting oxidative stress, and reducing intestinal epithelial apoptosis and ferroptosis. Notably, Amy administration remarkably lowered DSS-triggered TLR4 expression and the phosphorylation of proteins related to the NF-κB and MAPK pathways. Furthermore, Amy administration modulated the balance of intestinal flora, including a selective rise in the abundance of S24-7 and a decline in the abundance of Allobaculum, Oscillospira, Bacteroides, Sutterella, and Shigella. In conclusion, Amy can alleviate colitis, which provides data to support the utility of Amy in combating IBD.

Phlorizin (PHZ) is the main active component of apple peel and presents a potential application value. In the past few years, some reports have suggested that PHZ may have antioxidant and anti-inflammatory effects. Herein, we have attempted to assess the protective effects of PHZ on dextran sodium sulfate (DSS)-induced colitis in mice and to determine the underlying molecular mechanisms. Our results suggested that early intervention with PHZ (20, 40, and 80 mg/kg) significantly reduced the severity of DSS-induced colitis in mice, as presented by a longer colon, improved tight junction protein, decreased disease activity index, and attenuated inflammatory factors. Additionally, early intervention with + (20, 40, and 80 mg/kg) significantly inhibited ferroptosis by decreasing the surrogate ferroptosis marker levels (MDA and Iron Content). Additionally, PHZ (80 mg/kg) increased the diversity of intestinal flora in colitic mice by elevating the levels of beneficial bacteria (Lactobacillaceae and Muribaculaceae) and reducing the levels of harmful bacteria (Lachnospiraceae). This indirectly led to an increase in the amount of short-chain fatty acids. A fecal microbial transplantation (FMT) test was conducted to show that PHZ (80 mg/kg) ameliorated ulcerative colitis (UC) by regulating gut dysbiosis. In conclusion, early intervention with PHZ decreased DSS-induced colitis in mice by preserving their intestinal barrier and regulating their intestinal flora.

Ulcerative colitis (UC), one of the foremost common forms of inflammatory bowel disease, poses a serious threat to human health. Currently, safe and effective treatments are not available. This study investigated the protective effect of ginkgolide C (GC), a terpene lactone extracted from Ginkgo biloba leaves, on UC and its underlying mechanism. The results showed that GC remarkably mitigated the severity of DSS-induced colitis in mice, as demonstrated by decreased body weight loss, reduced disease activity index, mitigated tissue damage, and increased colon length. Furthermore, GC inhibited DSS-induced hyperactivation of inflammation-related signaling pathways (NF-κB and MAPK) to reduce the production of inflammatory mediators, thereby mitigating the inflammatory response in mice. GC administration also restored gut barrier function by elevating the number of goblet cells and boosting the levels of tight junction-related proteins (claudin-3, occludin, and ZO-1). In addition, GC rebalanced the intestinal flora of DSS-treated mice by increasing the diversity of the flora, elevating the abundance of beneficial bacteria, such as Lactobacillus and Allobaculum, and decreasing the abundance of harmful bacteria, such as Bacteroides, Oscillospira, Ruminococcus, and Turicibacter. Taken together, these results suggest that GC administration effectively alleviates DSS-induced colitis by inhibiting the inflammatory response, maintaining mucosal barrier integrity, and regulating intestinal flora. This study may provide a scientific basis for the rational use of GC in preventing colitis and other related diseases.