Gut microbiota: The key to the treatment of metabolic syndrome in traditional Chinese medicine - a case study of diabetes and nonalcoholic fatty liver disease

Natural bioactive compounds reprogram bile acid metabolism in MAFLD: Multi-target mechanisms and therapeutic implications

Metabolic-associated fatty liver disease (MAFLD) has become an increasingly prevalent liver disorder worldwide, being closely associated with obesity, metabolic syndrome, and insulin resistance. Bile acids (BAs), beyond their traditional role in lipid digestion, play a pivotal part in regulating lipid and glucose metabolism as well as inflammatory responses. Recent investigations have recognized BAs as key factors in the onset and progression of MAFLD, mainly via their interactions with nuclear receptors such as the farnesoid X receptor (FXR) and the G protein-coupled bile acid receptor (TGR5). Additionally, active compounds derived from traditional Chinese medicine (TCM) have shown promising potential in the treatment of MAFLD. This study systematically reviews and analyzes the molecular mechanisms and recent progress in the application of TCM active ingredients for MAFLD treatment, with a focus on their regulation of BAs. These active ingredients, including saponins, flavonoids, polysaccharides, and sterols, exert therapeutic effects through diverse mechanisms, such as modulating BA synthesis and mediating receptor-signaling pathways, and are expected to restore metabolic homeostasis.

Gegen-Qinlian decoction alleviates metabolic dysfunction-associated steatohepatitis by modulating the microbiota-bile acid axis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Metabolic dysfunction-associated steatohepatitis (MASH) is the progressive form of metabolic dysfunction-associated steatotic liver disease (MASLD), and is currently the most prevalent chronic liver disease worldwide. Gegen-Qinlian decoction (GQD), a classical Traditional Chinese Medicine (TCM) formula from Treatise on Febrile Diseases, has been historically used to treat heat-dampness syndromes. Recent studies revealed that GQD is effective in treating MASH, but the underlying mechanisms remain unknown.

AIM OF THE STUDY

This study aims to evaluate the therapeutic effect of GQD on MASH and explore the potential mechanisms targeting the gut microbiota-bile acid (BA) axis.

MATERIALS AND METHODS

Phytochemical profiling of GQD was performed using UPLC-Q-TOF-MS. MASH was induced in mice via a fructose-, palmitate-, and cholesterol-enriched (FPC) diet, followed by treatment with low-, medium-, or high-dose GQD. H&E and oil red O staining were utilized to examine the histological change, and serum lipids and enzymes were biochemically analyzed. 16SrDNA sequencing was applied to analyze the alteration of the gut microbiota, and the gas chromatography-mass spectrometry technique was introduced to investigate the fecal bile acid (BA) profile. Serum lipopolysaccharide (LPS) concentrations were analyzed by enzyme-linked immunosorbent assay. Intestinal tight junction proteins (ZO1, Occludin) and BA receptors (FXR, TGR5, and VDR) were detected by Western blot and immunofluorescence staining.

RESULTS

The quality of GQD was confirmed, and GQD treatment improved hepatic steatosis, reduced the content of liver triglyceride (20-40 % reduction, p < 0.01) and cholesterol (20-25 % reduction, p < 0.01) in FPC-induced MASH mice. High-dose GQD further decreased serum TC (3.97 ± 1.00 vs 5.51 ± 1.11, p < 0.05), LDL-c (0.53 ± 0.18 vs 1.07 ± 0.28, p < 0.01), ALT (31.90 ± 6.20 vs 47.90 ± 12.78, p < 0.05) and ALP (90.83 ± 13.46 vs 132.90 ± 23.67, p < 0.05) levels, suggesting the effects of GQD in counteracting metabolic inflammation. GQD treatment restored gut microbiota diversity and reversed gut dysbiosis by decreasing the abundance of pathogenic bacteria, resulting in reduced serum LPS while enhancing intestinal tight junction proteins (ZO1, Occludin). Concurrently, GQD treatment reshaped fecal BA profiles, increased intestinal TGR5/VDR expression, with BA shifts strongly correlating to microbiota changes.

CONCLUSION

GQD alleviated hepatic and metabolic disorders in MASH mice, possibly through reversing gut dysbiosis and modulating BA profile. Targeting the microbiota-BA axis represents a promising pattern for TCM prescriptions in treating MASH.

Exploring the Nutraceutical Potential of a Food-Medicine Compound for Metabolic-Associated Fatty Liver Disease via Lipidomics and Network Pharmacology

Metabolic-associated fatty liver disease (MAFLD) is a prevalent global health issue closely tied to dietary habits, impacting a significant portion of the adult population. MAFLD is linked to various metabolic disorders, elevating risks of cirrhosis and hepatocellular carcinoma and severely impacting patients' quality of life. While therapeutic research has progressed, effective food-based interventions remain scarce. Natural products, rich in bioactive compounds and offering health benefits, have gained attention for their potential in managing MAFLD. This study employed network pharmacology and lipidomics to investigate the therapeutic effects of Food and Medicine Homology (FMH) on MAFLD using a high-fat-diet-induced HepG2 cell model. We identified 169 potential bioactive components from Radix Puerariae, Hericium erinaceus, Rhizoma Curcumae longae, Camellia oleifera, and Hoveniae Dulcis Semen, constructing a drug-component-target network that highlighted 34 key targets. The characteristic components of this FMH compound solution (HSD) were identified using UPLC-QTOF-MS/MS. In vitro, HSD significantly reduced intracellular lipid accumulation, decreased inflammatory markers, and mitigated hepatocyte damage. Lipidomics analysis revealed significant alterations in lipid metabolites, suggesting HSD's potential to modulate sphingolipid and glycerophospholipid metabolism, thus improving MAFLD outcomes. This research underscores the critical role of the FMH complex in modulating lipid metabolism and inflammatory pathways, offering valuable insights for developing FMH-based dietary supplements and functional foods to alleviate MAFLD. By leveraging the synergistic effects of natural compounds, our findings hold significant implications for innovative nutritional strategies in managing this prevalent metabolic disorder.

Gut microbiota's role in the enhancement of type 2 diabetes treatment by a traditional Chinese herbal formula compared to metformin

Type 2 diabetes mellitus (T2DM) is a rapidly increasing metabolic disorder that poses a significant threat to global public health. Recent evidence suggests that targeting the gut microbiota through dietary and pharmaceutical interventions can effectively manage T2DM. In this study, we developed a novel Chinese herbal formula, CCM, specifically for T2DM, composed of Coptis rhizoma, Cinnamomi cortex, and Mume fructus. To evaluate CCM's efficacy and explore its underlying mechanisms, particularly the role of the gut microbiota, diabetic C57/db/db mice were administered different doses of CCM (low, medium, high) for 4 weeks, with normal C57 mice as healthy controls and metformin as a positive control. Comprehensive clinical indicators of T2DM were measured before and after treatment. High-throughput sequencing was used to assess changes in gut microbiome composition and function. Our results showed that CCM treatment, especially at medium and high doses, resulted in more significant improvements in blood glucose, lipid profiles, and body weight compared to metformin. The CCM-treated group also exhibited more significant changes in the microbial community structure compared to the metformin group, notably enriching three beneficial microbes (>40%): Bacteroidetes spp., Akkermansia spp., and Parabacteroides spp., which correlated with improved diabetic parameters. Further analysis identified that all four microbial metabolic pathways linked to lowering blood glucose were exclusively enriched in the CCM-treated group. Of the 10 pathways related to improved blood lipid levels, five were unique to CCM. These unique pathways enriched by CCM may explain its superior therapeutic effects, indicating its distinct mechanisms in modulating gut microbiota.IMPORTANCEOur study demonstrates that CCM outperforms metformin in managing key clinical indicators in type 2 diabetes mellitus (T2DM) model mice and induces more significant alterations in gut microbiota composition and function. Notably, the uniquely enriched beneficial microbes and microbial metabolic pathways in the CCM samples may explain its enhanced therapeutic effects compared to metformin. Consequently, these findings suggest that CCM offers a promising therapeutic strategy for T2DM, and further provide valuable insights into potential probiotic candidates (such as Bacteroidetes spp., Akkermansia spp., and Parabacteroides spp.) and newly identified functional pathways (such as chondroitin sulfate degradation, geraniol degradation, biotin biosynthesis, colonic acid building blocks biosynthesis, and the biosynthesis of vancomycin group antibiotics) that could be targeted for therapeutic intervention.

Saponin content in medicinal plants in response to application of organic and inorganic fertilizers: a meta-analysis

The application of fertilizers is a key agronomic practice in the artificial cultivation of medicinal plants, aiming to boost yields and enhance the levels of their bioactive constituents. However, systematic investigations on the influence of various fertilizers on the concentration of active compounds in saponin-containing medicinal plants remain insufficient. In this study, 966 experimental outcomes from 29 papers were analyzed via meta-analysis to examine the effects of organic fertilizers, inorganic fertilizers, and their combined application on the levels of different saponin monomers in medicinal plants. The findings from the meta-analysis revealed that inorganic fertilizers contribute positively to the accumulation of saponins such as Rg1 in ginseng, Rb1, Rc, Rd, Re, and Rg1, in addition to the saponins from Paris polyphylla, Dioscorea, Panax quinquefolius, and Platycodon grandiflorus. Moreover, the application of organic fertilizers was found to markedly elevate the concentrations of Notoginsenoside R1, Ginsenoside Rb1, Ginsenoside Rb2, Re, and Rg1, along with Lancemasid saponins and Quinoa saponins. The combined use of both organic and inorganic fertilizers was shown to effectively increase the levels of Notoginsenoside R1 and Panax ginsenosides, encompassing Rb1, Rb2, Rc, Rd, Re, and Rg1. Overall, the results suggest that both individual and combined applications of organic and inorganic fertilizers have a positive impact on the enhancement of saponin monomers in medicinal plants. However, inorganic fertilizers promote the increase of saponin content, their prolonged use may lead to soil compaction and acidification, which could compromise the yield and quality of medicinal plants. On the other hand, organic fertilizers improve the soil environment and stimulate saponin accumulation, they do not supply all the nutrients required for the sustained growth of these plants. Therefore, a balanced fertilization strategy combining both organic and inorganic fertilizers is recommended as the optimal approach for cultivating saponin-rich medicinal plants.

Seabuckthorn polysaccharides mitigate hepatic steatosis by modulating the Nrf-2/HO-1 pathway and gut microbiota

Non-alcoholic fatty liver disease (NAFLD) is becoming a significant global public health threat. Seabuckthorn (Hippophae rhamnoides L.) has been used in traditional Chinese medicine (TCM). The hypolipidemic effects of Seabuckthorn polysaccharides (SP) against high-fat diets (HFD)-induced NAFLD were systematically explored and compared with that of Bifidobacterium lactis V9 (B. Lactis V9). Results showed that HFD-induced alanine transaminase (ALT) and aspartate aminotransferase (AST) levels decreased by 2.8-fold and 4.5-fold, respectively, after SP supplementation. Moreover, the alleviating effect on hepatic lipid accumulation is better than that of B. Lactis V9. The ACC and FASN mRNA levels were significantly reduced by 1.8 fold (P < 0.05) and 2.3 folds (P < 0.05), respectively, while the CPT1α and PPARα mRNA levels was significantly increased by 2.3 fold (P < 0.05) and 1.6 fold (P < 0.05), respectively, after SP administration. SP activated phosphorylated-AMPK and inhibited PPARγ protein expression, improved serum oxidative stress and inflammation (P < 0.05). SP supplementation leads to increased hepatic expression of nuclear factor erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1) and Superoxide dismutase-2 (SOD-2). Furthermore, SP treatment improved HFD-induced intestinal dysbiosis. Lentisphaerae, Firmicutes, Tenericutes and Peptococcus sp., RC9_gut_group sp., and Parabacteroides sp. of the gut microbiota were significantly associated with hepatic steatosis and indicators related to oxidative stress and inflammation. Therefore, SP can mitigate hepatic lipid accumulation by regulating Nrf-2/HO-1 signaling pathways and gut microbiota. This study offers new evidence supporting the use of SP as a prebiotic treatment for NAFLD.

New aspects characterizing non-obese NAFLD by the analysis of the intestinal flora and metabolites using a mouse model

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem due to the high incidence affecting approximately one-third of the world's population. NAFLD is usually linked to obesity and excessive weight. A subset of patients with NAFLD expresses normal or low body mass index; thus, the condition is called non-obese NAFLD or lean NAFLD. However, patients and healthcare professionals have little awareness and understanding of NAFLD in non-obese individuals. Furthermore, preclinical results from non-obese animal models with NAFLD are unclear. Gut microbiota and their metabolites in non-obese/lean-NAFLD patients differ from those in obese NAFLD patients. Therefore, we analyzed the biochemical indices, intestinal flora, and intestinal metabolites in a non-obese NAFLD mouse model established using a methionine-choline-deficient (MCD) diet. The significantly lean MCD mice had a remarkable fatty liver with lower serum triglyceride and free fatty acid levels, as well as higher alanine transaminase and aspartate transaminase levels than normal mice. 16S RNA sequencing of fecal DNA showed that the overall richness and diversity of the intestinal flora decreased in MCD mice, whereas the Firmicutes:Bacteroidota ratio was increased. g_Tuzzerella, s_Bifidobacterium pseudolongum, and s_Faecalibaculum rodentium were the predominant species in non-obese NAFLD mice. Fecal metabolomics using liquid chromatography-tandem mass spectrometry revealed the potential biomarkers for the prognosis and diagnosis of non-obese NAFLD, including high levels of tyramine glucuronide, 9,12,13-TriHOME, and pantetheine 4'-phosphate, and low levels of 3-carbamoyl-2-phenylpropionaldehyde, N-succinyl-L,L-2,6-diaminopimelate, 4-methyl-5-thiazoleethanol, homogentisic acid, and estriol. Our findings could be useful to identify and develop drugs to treat non-obese NAFLD and lean NAFLD.

IMPORTANCE

Patients and healthcare professionals have little awareness and understanding of NAFLD in non-obese individuals. In fact, about 40% of people with NAFLD worldwide are non-obese, and nearly one-fifth are lean. Lean NAFLD unfortunately may be unnoticed for years and remains undetected until hepatic damage is advanced and the prognosis is compromised. This study focused on the lean NAFLD, screened therapeutic agents, and biomarkers for the prognosis and diagnosis using MCD-induced male C57BL/6J mice. The metabolites tyramine glucuronide, 9,12,13-TriHOME, and pantetheine 4'-phosphate, together with the predominant flora including g_Tuzzerella, s_Bifidobacterium pseudolongum, and s_Faecalibaculum rodentium, were specific in non-obese NAFLD mice and might be used as targets for non-obese NAFLD drug exploration. This study is particularly significant for non-obese NAFLDs that need to be more actively noticed and vigilant.