Anti-inflammatory and bioavailability studies on dietary 3,5,4'-trihydroxy-6,7-methylenedioxyflavone-O-glycosides and their aglycone from indigo leaves in a murine model of inflammatory bowel disease

Exploring the efficacy of herbal medicinal products as oral therapy for inflammatory bowel disease

Inflammatory bowel disease (IBD) encompasses a collection of idiopathic diseases characterized by chronic inflammation in the gastrointestinal (GI) tract. Patients diagnosed with IBD often experience necessitate long-term pharmacological interventions. Among the multitude of administration routes available for treating IBD, oral administration has gained significant popularity owing to its convenience and widespread utilization. In recent years, there has been extensive evaluation of the efficacy of orally administered herbal medicinal products and their extracts as a means of treating IBD. Consequently, substantial evidence has emerged, supporting their effectiveness in IBD treatment. This review aimed to provide a comprehensive summary of recent studies evaluating the effects of herbal medicinal products in the treatment of IBD. We delved into the regulatory role of these products in modulating immunity and maintaining the integrity of the intestinal epithelial barrier. Additionally, we examined their impact on antioxidant activity, anti-inflammatory properties, and the modulation of intestinal flora. By exploring these aspects, we aimed to emphasize the significant advantages associated with the use of oral herbal medicinal products in the treatment of IBD. Of particular note, this review introduced the concept of herbal plant-derived exosome-like nanoparticles (PDENs) as the active ingredient in herbal medicinal products for the treatment of IBD. The inclusion of PDENs offers distinct advantages, including enhanced tissue penetration and improved physical and chemical stability. These unique attributes not only demonstrate the potential of PDENs but also pave the way for the modernization of herbal medicinal products in IBD treatment.

Polygonum tinctorium leaf extract ameliorates high-fat diet-induced intestinal epithelial damage in mice

Dietary fat strongly influences the intestinal mucosal barrier, which protects against invading pathogenic bacteria. A high-fat diet (HFD) compromises the integrity of epithelial tight junctions (TJs) and reduces mucin production, leading to intestinal barrier disruption and metabolic endotoxemia. It has been shown that the active constituents of indigo plants can protect against intestinal inflammation; however, their protective role in HFD-induced intestinal epithelial damage remains unknown. The present study aimed to investigate the effects of Polygonum tinctorium leaf extract (indigo Ex) on HFD-induced intestinal damage in mice. Male C57BL6/J mice were fed a HFD and injected intraperitoneally with either indigo Ex or phosphate-buffered saline (PBS) for 4 weeks. The expression levels of TJ proteins, zonula occludens-1 and Claudin-1, were analyzed by immunofluorescence staining and western blotting. The colon mRNA expression levels of tumor necrosis factor-α, interleukin (IL)-12p40, IL-10 and IL-22 were measured by reverse transcription-quantitative PCR. The results revealed that indigo Ex administration attenuated the HFD-induced shortening of the colon. Colon crypt length was shown to be significantly greater in the indigo Ex-treated group mice compared with that in the PBS-treated group mice. Moreover, indigo Ex administration increased the number of goblet cells, and ameliorated the redistribution of TJ proteins. Notably, indigo Ex significantly increased the colon mRNA expression levels of IL-10. Indigo Ex displayed little effect on the gut microbial composition of HFD-fed mice. Taken together, these results suggested that indigo Ex may protect against HFD-induced epithelial damage. The leaves of indigo plants contain promising natural therapeutic compounds that could be used to treat obesity-associated intestinal damage and metabolic inflammation.

Painong-San extract alleviates dextran sulfate sodium-induced colitis in mice by modulating gut microbiota, restoring intestinal barrier function and attenuating TLR4/NF-κB signaling cascades

The intestinal barrier dysfunction and the gut microbiota dysbiosis with excessive progress of inflammation contribute to the occurrence and acceleration of ulcerative colitis (UC). Painong Powder, a traditional Chinese medicine prescription, consists of Aurantii Fructus Immaturus, Paeoniae Radix Alba and Platycodonis Radix, which has been found to defend against colitis, but it is unclear whether its role in preventing UC is related to gut microbiota. This study aims to evaluate the effects of Painong-San extract (PNS) on UC and reveals the mechanisms related to gut microbiota. Firstly, a total of 125 chemical compounds, including 42 flavonoids, 29 triterpenoids, 21 monoterpenoids, 11 polyphenols, 6 limonoids, 5 alkaloids, 4 coumarins and 7 other compounds, were identified from PNS using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Then, the results in vivo studies demonstrated that PNS treatment reduced the weight loss and the disease activity index, prevented colon shortening and alleviated colonic tissue damage in dextran sulfate sodium (DSS)-induced colitis mice. The intestinal barrier damage was repaired after PNS administration through promoting the expression of tight junction proteins (claudin-1, occludin and zonula occludens-1). More interestingly, PNS regulated gut microbiota dysbiosis, suppressed the overgrowth of conditional pathogenic gut bacteria, such as Oscillospiraceae and Helicobacter, while the probiotic gut microbiota like Romboutsia, Lactobacillus, Bifidobacterium and Akkermansia were increased. Furthermore, PNS remarkably ameliorated colonic inflammatory response through inhibiting intestinal TLR4/NF-κB signaling pathway by down-regulating the protein expressions of TLR4, MyD88, p-NF-κB p65 and p-IκBα. Taken together, PNS effectively improved DSS-induced colitis through the modulation of gut microbiota, restoration of intestinal barrier function and attenuation of TLR4/NF-κB signaling cascades, which may provide a new explanation of the mechanisms of PNS against UC.