Korean Traditional Medicine (Jakyakgamcho-tang) Ameliorates Colitis by Regulating Gut Microbiota

Orally Administered Ginkgolide C Attenuates DSS-Induced Colitis by Maintaining Gut Barrier Integrity, Inhibiting Inflammatory Responses, and Regulating 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.

Disrupted gut microbiota aggravates working memory dysfunction induced by high-altitude exposure in mice

BACKGROUND

The widely accepted microbiome-gut-brain axis (MGBA) hypothesis may be essential for explaining the impact of high-altitude exposure on the human body, especially brain function. However, studies on this topic are limited, and the underlying mechanism remains unclear. Therefore, this study aimed to determine whether high-altitude-induced working memory dysfunction could be exacerbated with gut microbiota disruption.

METHODS AND RESULTS

C57BL/6 mice were randomly divided into three groups: control, high-altitude exposed (HAE), and high-altitude exposed with antibiotic treatment (HAE-A). The HAE and HAE-A groups were exposed to a low-pressure oxygen chamber (60-65 kPa) simulating the altitude of 3,500-4,000 m for 14 days, The air pressure level for the control group was maintained at 94.5 kPa. Antibiotic water (mixed with 0.2 g/L of ciprofloxacin and 1 g/L of metronidazole) was provided to the HAE-A group. Based on the results of the novel object test and P300 in the oddball behavioral paradigm training test, working memory dysfunction was aggravated by antibiotic treatment. We determined the antioxidant capacity in the prefrontal cortex and found a significant negative influence (p < 0.05) of disturbed gut microbiota on the total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content, as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). The same trend was also observed in the apoptosis-related functional protein content and mRNA expression levels in the prefrontal cortex, especially the levels of bcl-2, Bax, and caspase-3. The high-altitude environment and antibiotic treatment substantially affected the richness and diversity of the colonic microbiota and reorganized the composition and structure of the microbial community. S24-7, Lachnospiraceae, and Lactobacillaceae were the three microbial taxa with the most pronounced differences under the stimulation by external factors in this study. In addition, correlation analysis between colonic microbiota and cognitive function in mice demonstrated that Helicobacteraceae may be closely related to behavioral results.

CONCLUSION

Disrupted gut microbiota could aggravate working memory dysfunction induced by high-altitude exposure in mice, indicating the existence of a link between high-altitude exposure and MGBA.

Holism of Chinese herbal medicine prescriptions for inflammatory bowel disease: A review based on clinical evidence and experimental research

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease that causes a heavy burden and lacks effective treatments. Chinese herbal medicine prescriptions (CHMPs), which are characterized by a synergistic usage of herbs, are widely used in the management of IBD. The molecular mechanisms of action of CHMP are still ambiguous as the canonical "one-compound-one-target" approach has difficulty describing the dynamic bioreactions among CHMP objects. It seems more flexible to define the holism of CHMP for IBD by employing high-throughput analysis. However, studies that discuss the development of CHMP in treating IBD in a holistic view are still lacking.

PURPOSE

This review appraised preclinical and clinical research to fully describe the anti-IBD capacity of CHMPs and discussed CHMPs' holistic characteristics that can contribute to better management of IBD.

METHODS & RESULTS

We screened clinical and preclinical references of CHMP being used as treatments for IBD. We discussed the complexity of IBD and the development of CHMP to present the sophistication of CHMP treatments. To describe the clinical effectiveness of CHMPs against IBD, we performed an umbrella review of CHMP-associated META analyses, in which 1174 records were filtered down to 12 references. Then, we discussed 14 kinds of CHMPs that had a long history of use and analyzed their mechanisms of action. Representative herbs were employed to provide a subordinate explanation for the whole prescription. As holism is the dominant characteristic of CHMPs, we explored applications of CHMPs for IBD with the help of omics, gut microbiome, and network pharmacology, which are potential approaches to a dynamic figure of bioactions of CHMPs.

CONCLUSION

This review is the first to discuss the potential of CHMPs to manage IBD in a holistic context and will provide inspiring explanations for CHMP applications for further product transformation and application to other diseases.

The Effects of Erchen Decoction on Gut Microbiota and Lipid Metabolism Disorders in Zucker Diabetic Fatty Rats

Obesity is a chronic metabolic disease caused by genetic and environmental factors that has become a serious global health problem. There is evidence that gut microbiota is closely related to the occurrence and development of obesity. Erchen Decoction (ECD), a traditional Chinese medicine, has been widely used for clinical treatment and basic research of obesity and related metabolic diseases in recent years. It can significantly improve insulin resistance (IR) and lipid metabolism disorders. However, there is no microbiological study on its metabolic regulation. In this study, we investigated the effects of ECD on obesity, especially lipid metabolism and the composition and function of gut microbiota in Zucker diabetic fatty (ZDF) rats, and explored the correlation between the biomarkers of gut microbiota and metabolite and host phenotype. The results showed that ECD could reduce body weight, improve IR and lipid metabolism, and reduce the concentration of free fatty acids (FFA) released from white adipose tissue (WAT) due to excessive lipolysis by interfering with the insulin receptor substrate 1 (IRS1)/protein kinase B (AKT)/protein kinase A (PKA)/hormone-sensitive triglyceride lipase (HSL) signaling pathway in ZDF rats. Additionally, ECD gradually adjusted the overall structure of changed gut microbiota, reversed the relative abundance of six genera, and changed the function of gut microbiota by reducing the content of propionic acid, a metabolite of gut microbiota, in ZDF rats. A potentially close relationship between biomarkers, especially Prevotella, Blautia, and Holdemania, propionic acid and host phenotypes were demonstrated through correlation analysis. The results suggested that the beneficial effects of ECD on obesity, especially lipid metabolism disorders, are related to the regulation of gut microbiota in ZDF rats. This provides a basis for further research on the mechanism and clinical application of ECD to improve obesity via gut microbiota.

Dietary Tangeretin Alleviated Dextran Sulfate Sodium-Induced Colitis in Mice via Inhibiting Inflammatory Response, Restoring Intestinal Barrier Function, and Modulating Gut Microbiota

In this study, the preventive effect of tangeretin (TAN), a natural flavonoid derivative from citrus fruits, on the dextran sulfate sodium (DSS)-induced colitis in mice was evaluated. Our results showed that dietary TAN (0.04% and 0.08% w/w in the diet) significantly reduced the severity of colitis caused by DSS treatment in mice, evidenced by the increased colon length, the reduced disease activity index, and the attenuated colonic tissue damages. Moreover, dietary TAN inhibited the inflammatory response via down-regulating the overexpression of colonic inflammatory cytokines. Immunohistochemical analysis revealed that the intestinal barrier function was restored by TAN through enhancing claudin-1 and ZO-1 expressions. Additionally, dietary TAN modulated gut microbiota in colitic mice via enhancing gut microbiota diversity, ascending the level of beneficial bacteria, e.g., Lachnospiraceae and Lactobacillaceae, and descending the level of harmful bacteria, e.g., Enterobacteriaceae and Alistipes. Besides, dietary TAN promoted short-chain fatty acids production in DSS-treated mice. Altogether, these findings provided scientific evidence for the rational utilization of TAN as a preventive agent against colonic inflammation and related diseases.

The Regulatory Effects of Licochalcone A on the Intestinal Epithelium and Gut Microbiota in Murine Colitis

The gut epithelium is a mechanical barrier that protects the host from the luminal microenvironment and interacts with the gut microflora, which influences the development and progression of ulcerative colitis (UC). Licochalcone A (LA) exerts anti-inflammatory effects against UC; however, whether it also regulates both the gut barrier and microbiota during colitis is unknown. The current study was conducted to reveal the regulatory effects of LA on the intestinal epithelium and gut microflora in C57BL/6 mice subjected to dextran sodium sulfate (DSS). Sulfasalazine (SASP) was used as the positive control. Results of clinical symptoms evaluation, hematoxylin, and eosin (H&E) staining, and enzyme-linked immunosorbent (ELISA) assays showed that LA significantly inhibited DSS-induced weight loss, disease activity index (DAI) increase, histological damage, and gut inflammation. Additionally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunohistochemical (IHC) analysis showed that LA maintained the integrity of the intestinal barrier by suppressing cell apoptosis and preserving the expression of tight junction (TJ) proteins. Notably, the optimal dose of LA for gut barrier preservation was low, while that for anti-inflammatory effects was high, indicating that LA might preserve gut barrier integrity via direct effects on the epithelial cells (ECs) and TJ proteins. Furthermore, 16S rRNA analysis suggested that the regulatory effect of LA on the gut microbiota differed distinctly according to dose. Correlation analysis indicated that a low dose of LA significantly modulated the intestinal barrier-associated bacteria as compared with a moderate or high dose of LA. Western blot (WB) analysis indicated that LA exhibited anti-UC activity partly by blocking the mitogen-activated protein kinase (MAPK) pathway. Our results further elucidate the pharmacological activity of LA against UC and will provide valuable information for future studies regarding on the regulatory effects of LA on enteric diseases.

Effects of S24-7 on the weight of progeny rats after exposure to ceftriaxone sodium during pregnancy

Antibiotic exposure during pregnancy will adversely affect the growth of offspring; however, this remains controversial and the mechanism is poorly understood. To study this phenomenon, we added ceftriaxone sodium to the drinking water of pregnant rats and continuously monitored the body weight of their offspring. The results showed that compared with the control group, the offspring exposed to antibiotics during pregnancy had a higher body weight up to 3 weeks old but had a lower body weight at 6 weeks old. To determine the role of the gut microbiota and its metabolites in the growth of offspring, we collected feces for sequencing and further established that the experimental group has a different composition ratio of dominant bacteria at 6 week old, among which S24–7 correlated negatively with body weight and the metabolites that correlated with body weight-related unique flora were L-Valine, L-Leucine, Glutaric acid, N-Acetyl-L-glutamate, and 5-Methylcytosine. To further explore how they affect the growth of offspring, we submitted these data to Kyoto Encyclopedia of Genes and Genomes website for relevant pathway analysis. The results showed that compared with the control, the following metabolic pathways changed significantly: Valine, leucine, and isoleucine biosynthesis; Protein digestion and absorption; and Mineral absorption. Therefore, we believe that our findings support the conclusion that ceftriaxone sodium exposure in pregnancy has a long-lasting adverse effect on the growth of offspring because of an imbalance of gut microbiota, especially S24–7, via different metabolic pathways.

Herbal Medicine and Acupuncture Combined Treatment Attenuates Colitis in Rats

This study aimed to verify the efficacy of a combined treatment of Jakyakgamcho-tang (JGT) and acupuncture (CV12, ST25, CV4) on colitis induced by dextrane sulfate sodium (DSS). Changes in immuno-mediated factors and metabolites were investigated. Colitis symptoms such as body weight loss and elevated disease activity index were alleviated by the combined treatment. Moreover, treatment with JGT and acupuncture restored the disturbed architecture of colon by suppressing inflammatory cytokine levels of IFN-[Formula: see text] ([Formula: see text] < 0.05), IL-5 ([Formula: see text] < 0.05), and IL-13 ([Formula: see text] < 0.0001) compared with the DSS group. Analysis of metabolic profiles of serum revealed that treatment groups were clearly separated from the DSS group, suggesting that JGT and acupuncture treatment altered serum metabolites. Furthermore, treatments caused opposite metabolite patterns for dimethylbenzimidazole, 1,5-anhydro-D-glucitol, proline, phosphate, glycolic acid, aspartic acid, tryptophan, phthalic acid, ornithine, and glutamic acid compared with the DSS group. The combined treatment group induced more effective metabolite patterns than the JGT group, implying that acupuncture treatment can restore metabolic changes caused by DSS induction. These results indicate that the simultaneous treatment of JGT administration and acupuncture procedure provides better management of the immune function and inflammatory expression of colitis than a single treatment. It is assumed that intestinal microbial control can be achieved by acupuncture stimulation as well as by taking herbal medicine.

The Extraction Solvent Influences the Anti-Inflammatory Effects of Jakyakgamcho-Tang in Lipopolysaccharide-Stimulated Macrophages and Mice with Gouty Arthritis

Jakyakgamcho-Tang (JGT) is a traditional medicine used to treat muscular tension, spasm, and pain. Several studies have reported its clinical use as an anti-inflammatory and in gynaecological treatment. This study aimed to compare the anti-inflammatory effects of JGT according to extraction solvent, water (JGTW) and 30% EtOH (JGTE) on lipopolysaccharide (LPS)—stimulated macrophages and in mice with monosodium urate (MSU)—induced gouty arthritis. We evaluated the production of inflammatory mediators and cytokines and the expression of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX-2) in RAW 264.7 cells. We also examined oedema, pain, and inflammation in MSU-induced mice by measuring affected hind paw swelling, weight-bearing, pro-inflammatory cytokines levels, and myeloperoxidase (MPO) activity. In LPS-stimulated RAW264.7 cells, JGTW and JGTE significantly decreased prostaglandin (PG) E2(PGE2) production via suppressing COX-2 expression and cytokines interleukin-1β and interleukin-6. Only JGTE reduced the production of NO and cytokines and the mRNA levels of iNOS and cytokines. In MSU-induced mice, JGTE and JGTW efficiently decreased paw swelling and attenuated joint pain. JGTE (200 and 300 mg/kg) effectively suppressed inflammation by downregulating pro-inflammatory cytokines (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) and MPO activity, which were only slightly reduced by JGTW. Our data demonstrate the anti-inflammatory activity of JGT in macrophage and gouty arthritis animal models and show that JGTE is more effective than JGTW at lower concentrations.