Pure total flavonoids from citrus improve non-alcoholic fatty liver disease by regulating TLR/CCL signaling pathway: A preliminary high-throughput 'omics' study

Mechanistic study of fructus aurantii (Quzhou origin) in regulating ileal reg3g in the treatment for NASH

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a critical stage in the progression of non-alcoholic fatty liver disease (NAFLD), characterized by obvious inflammation and fibrosis. Because of its high incidence rate and serious consequences, NASH is becoming a global health problem. The influence of endotoxin translocation on NASH is receiving attention. As a traditional Chinese herb that effectively improves hepatic inflammation, Fructus Aurantii (Quzhou origin, FAQ) is widely used in the clinical treatment of NASH. However, the intervention mechanism of FAQ on reg3g and related endotoxin translocation remains unclear.

AIM

To study the mechanism of the impact by which ileal regenerating family member 3 gamma (reg3g) deficiency and subsequent endotoxin translocation impact the progression of NASH; To elucidate the efficacy and mechanism of FAQ in the treatment of NASH.

METHODS

Clinical serum, ileal tissue, and dynamic NASH model-related analyses collectively confirmed that reg3g is a pivotal gene associated with NASH. Reg3g-/- mice were used to assess the impact of reg3g on liver injury, inflammation, and fibrosis, as well as the underlying mechanism involved. In vitro studies elucidated the regulatory effects of FAQ on reg3g, intestinal barrier function, and intestinal permeability. Subsequently, the efficacy of FAQ was investigated in NASH mouse models. Pathological examinations combined with Western blotting (WB), immunohistochemistry (IHC), and multiplex immunohistochemical (mIHC) analyses were used to evaluate the effects of FAQ on mucosal repair and barrier function. Transepithelial electrical resistance (TEER), fluorescein isothiocyanate-dextran 4 (FD-4) experiments, coupled with enzyme linked immunosorbent assay (ELISA) and chromogenic LAL endotoxin assay were used to confirm intestinal permeability and endotoxin translocation. The results of WB and mIHC reflected the levels of endotoxin recruitment and M1 macrophage polarization in the liver. Parameters such as body weight, transaminases, and cholesterol were utilized to assess the metabolic effects of FAQ.

RESULTS

Decreased expression of reg3g was associated with the progression of NASH. Ileal deficiency in reg3g resulted in damage to the intestinal barrier and permeability, leading to the recruitment of endotoxins via the 'gut-liver' axis to the liver, causing the polarization of M1 macrophages, release of inflammatory factors, excessive inflammation, and activation of hepatic stellate cells (HSCs), leading to fibrosis. FAQ significantly upregulated ileal reg3g expression and the expression of intestinal barrier-related proteins tight junction protein 1 (ZO-1) and occludin (OLCN) in mice (p < 0.05), thereby improving intestinal barrier function and permeability. Reduced intestinal permeability led to decreases in endotoxins entering the bloodstream and accumulating in the liver (p < 0.05). The expression of CD68 suggested reduced polarization of M1 macrophages. Expression levels of actin alpha 2, smooth muscle actin (α-SMA) and extracellular matrix (ECM)-related proteins also decreased, indicating improved liver fibrosis.

CONCLUSION

FAQ ameliorates NASH by upregulating the expression of reg3g. The upregulation of reg3g contributes to the repair of the intestinal barrier and permeability, reducing the recruitment of endotoxins and subsequent polarization of M1 macrophages, excessive inflammation, and fibrosis.

Chinese medicine in the treatment of non-alcoholic fatty liver disease based on network pharmacology: a review

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by abnormalities in hepatic fat deposition, the incidence of which has been increasing year by year in recent years. It has become the largest chronic liver disease globally and one of the important causes of cirrhosis and even primary liver cancer formation. The pathogenesis of NAFLD has not yet been fully clarified. Modern medicine lacks targeted clinical treatment protocols for NAFLD, and most drugs lack efficacy and have high side effects. In contrast, Traditional Chinese Medicine (TCM) has significant advantages in the treatment and prevention of NAFLD, which have been widely recognized by scholars around the world. In recent years, through the establishment of a "medicine-disease-target-pathway" network relationship, network pharmacology can explore the molecular basis of the role of medicines in disease prevention and treatment from various perspectives, predicting the pharmacological mechanism of the corresponding medicines. This approach is compatible with the holistic view and treatment based on pattern differentiation of TCM and has been widely used in TCM research. In this paper, by searching relevant databases such as PubMed, Web of Science, and Embase, we reviewed and analyzed the relevant signaling pathways and specific mechanisms of action of single Chinese medicine, Chinese medicine combinations, and Chinese patent medicine for the treatment of NAFLD in recent years. These related studies fully demonstrated the therapeutic characteristics of TCM with multi-components, multi-targets, and multi-pathways, which provided strong support for the exact efficacy of TCM exerted in the clinic. In conclusion, we believe that network pharmacology is more in line with the TCM mindset of treating diseases, but with some limitations. In the future, we should eliminate the potential risks of false positives and false negatives, clarify the interconnectivity between components, targets, and diseases, and conduct deeper clinical or experimental studies.

Pure total flavonoids from citrus improve nonalcoholic steatohepatitis liver inflammatory responses by regulating the CCL2/CCR2-PI3K-Akt signal transduction pathway

BACKGROUND AND AIM

Nonalcoholic steatohepatitis (NASH) is a critical stage in the prognosis of nonalcoholic fatty liver disease (NAFLD). Pure total flavonoids from circus (PTFC) play essential roles in the improvement of NASH symptoms, but the underlying regulatory mechanism remains elusive. Our previous high-throughput omics screening results indicate that the CCL2/CCR2-PI3K-Akt signaling pathway is a key pathway that regulates the liver inflammatory response. PTFC may regulate the CCL2/CCR2-PI3K-Akt signaling pathway to improve the liver inflammatory response.

METHODS

A mice model of NASH was established by a high-fat diet, and PTFC was used as treatment. Hematoxylin-eosin and oil red O staining were used to observe the pathological changes in the liver tissue. Western blotting and real-time PCR were used to measure the mRNA and protein levels in the liver. The expression of proinflammatory cytokines in the peripheral blood and liver tissues was measured by liquid suspension array. An automatic biochemical method was used to examine serum transaminases and lipids levels, as well as liver lipids.

RESULTS

Compared with the mice in the high-fat diet group, mice in the HFD + PTFC group showed significantly improved liver histopathology, and levels of serum transaminase and lipids, liver lipids and serum proinflammatory cytokines. Moreover, the mRNA and protein expression and phosphorylation levels of key signaling molecules in the CCL2/CCR2-PI3K-Akt signal transduction pathway were obviously reduced by PTFC treatment.

CONCLUSIVE REMARKS

PTFC can ameliorate NASH symptoms, and the mechanism may be related to regulating the CCL2/CCR2-PI3K-Akt signal transduction pathway to reduce the liver inflammatory response.

Pure total flavonoids from citrus alleviate oxidative stress and inflammation in nonalcoholic fatty liver disease by regulating the miR-137-3p/NOXA2/NOX2 pathway

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become a global health issue owing to its large disease population and high morbidity. We previously reported that the improvement in oxidative stress (OS) using pure total flavonoids from citrus (PTFC), flavonoids isolated from the peel of Citrus changshan-huyou Y.B. Chan, is a crucial strategy for NAFLD treatment. However, OS-associated intervention pathways in NAFLD remain unclear.

METHODS

In this study, we used microRNA (miR)- and mRNA-sequencing to identify the pathway by which PTFC improve OS in NAFLD. Clinical data, mimic/inhibitor assays, and a dual-luciferase reporter assay were selected to verify the regulatory relationships of this pathway. Moreover, in vivo and in vitro experiments were used to confime the regulatory effect of PTFC on this pathway.

RESULTS

miR-seq, mRNA-seq, and bioinformatics analyses revealed that the miR-137-3p/neutrophil cytosolic factor 2 (NCF2, also known as NOXA2)/cytochrome b-245 beta chain (CYBB, also known as NOX2) pathway may be a target pathway for PTFC to improve OS and NAFLD. Additionally, bivariate logistic regression analysis combining the serum and clinical data of patients revealed NOX2 and NOXA2 as risk factors and total antioxidant capacity (indicator of OS level) as a protective factor for NAFLD. miR-137-3p mimic/inhibitor assays revealed that the upregulation of miR-137-3p is vital for improving cellular steatosis, OS, and inflammation. Dual-luciferase reporter assay confirmed that NOXA2 acts as an miR-137-3p sponge. These results co-determined that miR-137-3p/NOXA2/NOX2 is an essential pathway involved in NAFLD pathogenesis, including lipid accumulation, OS, and inflammation. In vivo and in vitro experiments further confirmed that the miR-137-3p/NOXA2/NOX2 pathway is regulated by PTFC.

CONCLUSION

PTFC alleviates OS and inflammation in NAFLD by regulating the miR-137-3p/NOXA2/NOX2 pathway.

Can Antioxidants Reduce the Toxicity of Bisphenol?

BPA is still the subject of extensive research due to its widespread use, despite its significant toxicity resulting not only from its negative impact on the endocrine system but also from disrupting the organism’s oxidative homeostasis. At the molecular level, bisphenol A (BPA) causes an increased production of ROS and hence a change in the redox balance, mitochondrial dysfunction, and modulation of cell signaling pathways. Importantly, these changes accumulate in animals and humans, and BPA toxicity may be aggravated by poor diet, metabolic disorders, and coexisting diseases. Accordingly, approaches using antioxidants to counteract the negative effects of BPA are being considered. The preliminary results that are described in this paper are promising, however, it should be emphasized that further studies are required to determine the optimal dosage and treatment regimen to counteract BPA toxicity. It also seems necessary to have a more holistic approach showing, on the one hand, the influence of BPA on the overall human metabolism and, on the other hand, the influence of antioxidants in doses that are acceptable with the diet on BPA toxicity. This is due in part to the fact that in many cases, the positive effect of antioxidants in in vitro studies is not confirmed by clinical studies. For this reason, further research into the molecular mechanisms of BPA activity is also recommended.

Pure Total Flavonoids From Citrus Protect Against Nonsteroidal Anti-inflammatory Drug-Induced Small Intestine Injury by Promoting Autophagy in vivo and in vitro

Small intestine injury is an adverse effect of non-steroidal anti-inflammatory drugs (NSAIDs) that urgently needs to be addressed for their safe application. Although pure total flavonoids from citrus (PTFC) have been marketed for the treatment of digestive diseases, their effects on small intestine injury and the underlying mechanism of action remain unknown. This study aimed to investigate the potential role of autophagy in the mechanism of NSAID (diclofenac)-induced intestinal injury in vivo and in vitro and to demonstrate the protective effects of PTFC against NSAID-induced small intestine disease. The results of qRT-PCR, western blotting, and immunohistochemistry showed that the expression levels of autophagy-related 5 (Atg5), light chain 3 (LC3)-II, and tight junction (TJ) proteins ZO-1, claudin-1, and occludin were decreased in rats with NSAID-induced small intestine injury and diclofenac-treated IEC-6 cells compared with the control groups. In the PTFC group, Atg5 and LC3-II expression, TJ protein expression, and the LC3-II/LC3-I ratio increased. Furthermore, the mechanism by which PTFC promotes autophagy in vivo and in vitro was evaluated by western blotting. Expression levels of p-PI3K and p-Akt increased in the intestine disease-induced rat model group compared with the control, but decreased in the PTFC group. Autophagy of IEC-6 cells was upregulated after treatment with a PI3K inhibitor, and the upregulation was significantly more after PTFC treatment, suggesting PTFC promoted autophagy through the PI3K/Akt signaling pathway. In conclusion, PTFC protected intestinal barrier integrity by promoting autophagy, which demonstrates its potential as a therapeutic candidate for NSAID-induced small intestine injury.

Pure total flavonoids from citrus attenuate non-alcoholic steatohepatitis via regulating the gut microbiota and bile acid metabolism in mice

BACKGROUND

Our previous studies found that Pure total flavnoids from citrus (PTFC) can effectively improve non-alcoholic steatohepatitis (NASH) in mice. Here, we discuss on the mechanism of PTFC in treating NASH with focus on the regulation of the gut microbiota and bile acid metabolism.

METHODS

C57BL/6 J mice were randomly divided into three groups: normal diet group (Normal), high-fat diet group (HFD) and high-fat + PTFC treatment group (PTFC). Mice in the Normal group were fed chow diet, while the other groups were fed high fat diet (HFD) for 16 weeks. In the 5th week, the mice in the PTFC group were treated with 50 mg/kg/day PTFC for an additional twelve weeks. After sacrifice, histopathology of the liver was assessed, and the gut microbial composition was analyzed by 16S rDNA gene sequencing. Bile Acid profiles in serum were determined by ultraperformance liquid chromatography (UPLC-MS/MS).

RESULTS

PTFC intervention significantly attenuated HFD-induced NASH symptoms compared with the HFD group in mice. 16S rDNA sequencing showed that PTFC treatment increased the phylogenetic diversity of the HFD-induced microbiota dysbiosis. PTFC intervention significantly increased the relative abundances of Bacteroidaceae and Christensenellaceae. Furthermore, PTFC reduced the content of toxic bile acids, such as TDCA, DCA, TCA, CA and increased the ratio of secondary to primary bile acids. FXR and TGR5 deficiency were significantly alleviated.

CONCLUSION

PTFC can improve NASH via the the gut microbiota and bile acid metabolism.

The Target MicroRNAs and Potential Underlying Mechanisms of Yiqi-Bushen-Tiaozhi Recipe against-Non-Alcoholic Steatohepatitis

MicroRNAs (miRNAs) have emerged as potential therapeutic targets for non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH). Traditional Chineses Medicine (TCM) plays an important role in the prevention or treatment of NAFLD/NASH. However, miRNA targets of TCM against NASH still remain largely unknown. Here, we showed that Yiqi-Bushen-Tiaozhi (YBT) recipe effectively attenuated diet-induced NASH in C57BL/6 mice. To identify the miRNA targets of YBT and understand the potential underlying mechanisms, we performed network pharmacology using miRNA and mRNA deep sequencing data combined with Ingenuity Pathway Analysis (IPA). Mmu-let-7a-5p, mmu-let-7b-5p, mmu-let-7g-3p and mmu-miR-106b-3p were screened as the main targets of YBT. Our results suggested that YBT might alleviate NASH by regulating the expression of these miRNAs that potentially modulate inflammation/immunity and oxidative stress. This study provides useful information for guiding future studies on the mechanism of YBT against NASH by regulating miRNAs.

Mixtures of Tea and Citrus maxima (pomelo) Alleviate Lipid Deposition in HepG2 Cells Through the AMPK/ACC Signaling Pathway

Tea and citrus maxima are natural, medicinal homologous plants, typically used for making beverages, which have anticancer, antiobesity, and antioxidation properties. Green tea, yellow tea, and black tea were combined with citrus maxima to obtain green tea and Citrus maxima (GTCM), yellow tea and Citrus maxima (YTCM), and black tea and Citrus maxima (BTCM). The biochemical components of these mixtures were analyzed, and their possible effects and mechanisms on relieving liver lipid deposition were explored. The tea polyphenols, free amino acids, phenolamine ratio, and caffeine were comparable in YTCM and GTCM, being significantly higher than those in BTCM. In addition, the content of esterified catechins, nonesterified catechins, and total catechins in YTCM was significantly higher than those in GTCM and BTCM. All three mixtures of Citrus maxima tea significantly reduced lipid deposition in HepG2 cells, with GTCM and YTCM being slightly more effective than BTCM. Regarding the possible mechanism, Western blot analysis revealed that the three Citrus maxima tea mixtures could activate the AMPK/ACC signaling pathway, upregulate the expression of p-AMPK, p-ACC, and CPT-1 proteins, and downregulate the expression of SREBP1c and fatty acid synthase proteins to inhibit fat synthesis, thereby relieving lipid deposition in liver cells. In conclusion, as a novel and healthy beverage, Citrus maxima tea has the potential to alleviate liver lipid deposition, and further could be responsible for obesity treatment.

Citrus reticulata Blanco peel extract ameliorates hepatic steatosis, oxidative stress and inflammation in HF and MCD diet-induced NASH C57BL/6 J mice

Excessive lipid deposition, oxidative stress and inflammation in liver tissues are regarded as crucial inducers of nonalcoholic steatohepatitis (NASH), which is the most frequent chronic liver disease and closely related to obesity and insulin resistance. In this work, the preventive and therapeutic effects of Citrus reticulata Blanco (Jizigan) peel extract (JZE) on NASH induced by high fat (HF) diet and methionine choline-deficient (MCD) diet in C57BL/6 mice were investigated. We found that daily supplementation of JZE with an HF diet effectively ameliorated glucose tolerance and insulin resistance. In addition, the key indexes of lipid profiles, oxidative stress, hepatic steatosis and inflammatory factors were also ameliorated in both NASH mouse models. Furthermore, JZE treatment activated nuclear factor erythroid-2-related factor 2 (Nrf2) in the livers of diet- induced NASH mice. Our study suggests that JZE might alleviate NASH via the activation of Nrf2 signaling and that citrus Jizigan could be used as a dietary therapy for NASH and related metabolic syndrome.

Hypolipidemic effect of pure total flavonoids from peel of Citrus (PTFC) on hamsters of hyperlipidemia and its potential mechanism

Citrus is a group of popular fruit that includes oranges, lemons, limes and grapefruit but research of its peel on hyperlipidemia and its mechanism is rare reported. We examined the effect of pure total flavonoids from peel of Citrus (PTFC), an extract from the peel of Citrus Changshan-huyou which is a popular fruit in China, on hamsters with hyperlipoidemia induced by high-fat diet (HFD). We found that PTFC significantly reduced levels of serum cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-c) and improved levels of alanine transaminase (ALT), aspartate transaminase (AST) and Alkaline phosphatase (ALP) which associated with liver function in golden hamsters. Liver pathological results confirmed that the liver pathological section of golden hamster treated with PTFC was significantly improved compared with that of HFD group. The content of main cholesterol metabolic enzymes Cholesterol 7a-hydroxylase (CYP7A1) in liver was obviously recovered with PTFC treatment. Further studies shown that PTFC attenuated oxidative stress and free radical damage through superoxide dismutase (SOD) and malonyldialdehyde (MDA) tests and inflammatory injury by levels of Tumor Necrosis Factor-alpha (TNF-α) and interleukin-6 (IL-6) both in serum and hepatocyte of golden hamsters. Moreover, PTFC increased levels of RNA and protein expression of Peroxisome proliferator-activated receptor-α (PPAR-α) and PPAR-γ in liver, fat and skeletal muscle of hyperlipidemia golden hamster, significantly. Our results suggested that PTFC could play a hypolipidemic role through improvement of liver function by antioxidant and anti-inflammatory effects in hyperlipoidemia hamsters, its mechanism of action may through activating of PPARα and PPARγ.

Prediction of VEGF-C as a Key Target of Pure Total Flavonoids From Citrus Against NAFLD in Mice via Network Pharmacology

Pure total flavonoids from Citrus (PTFC) effectively reduce the symptoms of non-alcoholic fatty liver disease (NAFLD). Our previous microarray analysis uncovered the alterations of important signaling pathways in the treatment of NAFLD with PTFC. However, the underlying core genes that might be targeted by PTFC, which play important roles in the progression of NALFD are yet to be identified. In this study, we predicted the vascular endothelial growth factor-C (VEGF-C) as potential key molecular target of PTFC against NAFLD via network pharmacology analysis. The network pharmacology approach presented here provided important clues for understanding the mechanisms of PTFC treatment in the development of NAFLD.

Postgenomic Properties of Natural Micronutrients

Modern medical approaches to the therapy of various diseases, including cancer, are based on the use of toxic drugs. The unfavorable side effects of traditional medicine could be counterbalanced by addition of natural bioactive substances to conventional therapy due to their mild action on cells combined with the multitargeted effects. To elucidate the real mechanisms of their biological activity, versatile approaches including a number of "omics" such as genomics, transcriptomics, proteomics, and metabolomics are used. This review highlights inclusion of bioactive natural compounds into the therapy of chronic diseases from the viewpoint of modern omics-based nutritional biochemistry. The recently accumulated data argue for necessity to employ nutrigenetic and nutrimetabolomic analyses to prevent or diminish the risk of chronic diseases.

Citri Reticulatae Pericarpium (Chenpi): Botany, ethnopharmacology, phytochemistry, and pharmacology of a frequently used traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Citri Reticulatae Pericarpium (Rutaceae, CRP), commonly called as Chenpi () in Chinese, is most frequently used as a qi-regulating drug in thousands of Chinese medicine prescriptions. CRP is found mainly in major citrus-producing areas such as the Guangdong, Guangxi, Sichuan, Fujian, and Zhejiang Provinces of China. Since thousands of years in China, CRP has been used widely in clinical practice to treat nausea, vomiting, indigestion, anepithymia, diarrhea, cough, expectoration, and so on. Currently, CRP is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviews the botany, ethnopharmacology, phytochemistry, pharmacology, quality control, and toxicology of CRP.

MATERIALS AND METHODS

Information on CRP was gathered from various sources including the books on traditional Chinese herbal medicine; scientific databases including Elsevier, PubMed, and ScienceDirect; Baidu Scholar; CNKI; and others and from different professional websites.

RESULTS

Approximately 140 chemical compounds have been isolated and identified from CRP. Among them, volatile oils and flavonoids are generally considered as the main bioactive and characteristic ingredients. CRP possesses wide pharmacological effects such as having a beneficial effect on the cardiovascular, digestive, and respiratory systems, antitumor, antioxidant, and anti-inflammatory properties; and a protective effect on the liver and nerve. Moreover, hesperidin is chosen as an indicator in the quantitative determination of CRP, and the quantity of aflatoxin in CRP must not exceed the standard limit mentioned in the pharmacopoeia.

CONCLUSIONS

In brief, CRP has a warming nature, and hence, it can be used in harmony with a lot of medicines. CRP not only exhibits its effects individually but also aids other medicines exhibit a better effect. CRP can be consumed with tea, food, alcohol, and medicine. Irrespective of the form it is being consumed, CRP not only shows a synergistic effect but also has strengths on its own. Modern pharmacological studies have demonstrated that CRP has marked bioactivities, especially on the diseases of the digestive and respiratory systems. The bioactivities of CRP are useful for its clinical application and provide prospects for the development of drugs as well as food and health products for people. Although CRP is a commonly used drug in the traditional Chinese herbal prescription, there is an urgent need for further research on its synergistic effect with other herbs based on the compatibility theory of TCM, which would further increase our understanding on the compatibility theory of TCM.