Intestinal bacteria are involved in Radix Glycyrrhizae and Radix Euphorbiae Pekinensis incompatibility

Quercetin protects against hyperglycemia-induced retinopathy in Sprague Dawley rats by regulating the gut-retina axis and nuclear factor erythroid-2-related factor 2 pathway

Hyperglycemia-related retinopathy is a disease with a high blindness rate. Recent reports indicate that many flavonol compounds have the potential to prevent the occurrence of disease in the retina by regulating the gut-retina axis. Here, we hypothesized that quercetin could alleviate the symptoms of retinopathy. To clarify the mechanism, Sprague Dawley rats were fed a high-fat diet containing quercetin for 12 weeks and injected with streptozotocin in the ninth week. Additionally, neomycin and ampicillin were used to establish a pseudo-sterile rat model. Afterward, changes in the retina were investigated by using electroretinogram and optical coherence tomography. Blood and tissue samples were collected and biochemical components were analyzed. The extent of intestinal injury was determined via hematoxylin-eosin staining. Microbial community structure was analyzed by using 16S ribosomal RNA sequencing. Finally, the expression of genes was analyzed using real-time polymerase chain reaction. The results showed that quercetin reduced the decline in electroretinography amplitude and outer nuclear layer thickness, increased the activities of antioxidant enzymes, decreased the contents of proinflammatory factors and blood glucose, enhanced the concentration of insulin, and inhibited intestinal dysbiosis and improved gut morphology. Importantly, the underexpression of nuclear factor erythroid-2 related factor 2 in the retina was reversed by quercetin. However, trend changes were no longer significant in most of the indicators after antibiotic treatment. In summary, quercetin has therapeutic effects on retinopathy by regulating the gut-retina axis and nuclear factor erythroid-2 related factor 2 pathway, and the presence of gut microbiota helps quercetin exert its effects on the retina.

Prevention and treatment of rheumatoid arthritis through traditional Chinese medicine: role of the gut microbiota

Recently, despite the increasing availability of treatments for Rheumatoid arthritis (RA), the incidence of RA and associated disability-adjusted life years have been on the rise globally in the late decades. At present, accumulating evidence has been advanced that RA is related to the gut microbiota, therefore, the therapeutic approaches for RA by regulating the gut microbiota are anticipated to become a new means of treatment. Traditional Chinese medicine (TCM) can regulate immunity, reduce inflammation and improve quality of life in various ways. Moreover, it can treat diseases by affecting the gut microbiota, which is a good way to treat RA. In this review, we mainly explore the relationship between TCM and gut microbiota regarding the perspective of treating RA. Moreover, we comprehensively summarize the roles of gut microbiota in the onset, development, progression, and prognosis of RA. Additionally, we elucidate the mechanism of TCM prevention and treatment of RA by the role of microbiota. Finally, we provide an evidence-based rationale for further investigation of microbiota-targeted intervention by TCM.

Scientific connotation of the compatibility of traditional Chinese medicine from the perspective of the intestinal flora

Revealing the connotation of the compatibility of Chinese medicines (CM) is a requirement for the modernization of traditional Chinese medicine (TCM). However, no consensus exists on the specific mechanism of traditional Chinese medicine compatibility (TCMC). Many studies have shown that the occurrence and development of diseases and the efficacy of CM are closely related to intestinal flora (IF), which may provide a new perspective to understand the theory of TCM. This study aimed to summarize the relationship between the changes in IF before and after the compatibility of different drugs and the synergistic, toxicity reduction, and incompatibility effects of drug pairs from the perspective of the effects of CM on the IF and the regulation of microbial metabolites. These studies showed that the effect of drug pairs on the composition of the IF is not a simple superposition of two single drugs, and that the drug pairs also play a specific role in regulating the production of intestinal bacterial metabolites; therefore, it has a different pharmacodynamic effect, which may provide a perspective to clarify the compatibility mechanism. However, research on the interpretation of the scientific connotations of TCMC from the perspective of the IF is still in its infancy and has limitations. Therefore, this study aimed to summarize previous research experience and proposed to conduct a deep and systematic study from the perspective of drug pair dismantling, IF, intestinal bacteria metabolite, organism, and disease to provide a reference for scientific research on the compatibility mechanism of CM.

UGTs-mediated metabolic interactions contribute to enhanced anti-inflammation activity of Jinhongtang

ETHNOPHARMACOLOGICAL RELEVANCE

Jinhongtang, a traditional Chinese medicine (TCM) formula consisting of dry stems of Rheum palmatum L. (Polygonaceae) and Sargentodoxa cuneata (Oliv.) Rehder & E.H.Wilson (Lardizabalaceae) and whole plant of Taraxacum mongolicum Hand.-Mazz. (Asteraceae), is widely used for the treatment of infection diseases including severe sepsis and COVID-19.

AIM OF THE STUDY

The present study aimed to explore the compatibility mechanism in the prescription of Jinhongtang based on the pharmacokinetic interaction.

MATERIALS AND METHODS

CLP-induced sepsis mice and LPS-induced RAW264.7 cells were used to explore the anti-inflammatory effect of Jinhongtang and herbs in this clinical prescription. Pharmacokinetics of active components in Jinhongtang (Rhein, Emodin and Aloe emodin) was studied in rats. In vitro analysis of metabolic pathways and interactions mediated by metabolic enzymes were conducted using human liver microsomes (HLMs) and recombinant UGT isoforms.

RESULTS

Jinhongtang exhibited much more potent anti-inflammatory effect than its single herbs on CLP-induced sepsis mice and LPS-induced RAW264.7 cells. Next, the bioavailability of active ingredients (Rhein, Emodin and Aloe emodin) in R. palmatum was significantly improved through reduced metabolic clearance when co-administered with S. cuneata and T. mongolicum as Jinhongtang during the in vivo pharmacokinetic study, which presented the rational herbal compatibility mechanism. In detailed, the components in S. cuneata and T. mongolicum including Sargentodoxoside A, Chanitracin Ia, Quercetin and Luteolin inhibited the UGT1A9-mediated glucuronidation of active ingredients in R. palmatum, with K_i values of 2.72 μM, 1.25 μM, 2.84 μM and 0.83 μM, respectively.

CONCLUSION

T. mongolicum and S. cuneata, the adjuvant herbs of Jinhongtang, could reduce the metabolic clearance of key active components of R. palmatum, prolong their action time and further enhance their anti-inflammatory activity via inhibition of UGTs. Our findings provided deep insight for the rational compatibility of TCMs and useful guidance for the development of TCM formula.