Rhein, which is one of the main active components of Rheum palmatum, has a range of pharmacological activities such as the regulation of the metabolism of glucose and lipids, anti-inflammatory, anti-tumor, anti-fibrosis, etc. Epigenetics refers to the heritable variation of gene expression without altering the DNA sequence. It is involved in the emergence and development of inflammation, renal fibrosis, diabetes, cancer, atherosclerosis, and other diseases, thus becoming a new strategy for the treatment of many di-seases. A series of studies have shown that epigenetic modification may be a common molecular mechanism of various pharmacological effects of rhein. This paper summarized the effects of rhein on the regulation of epigenetic modification and its underlying mechanisms, which involve the regulation of DNA methylation, protein acetylation, and RNA methylation, so as to provide a basis for the development and application of rhein.
Humans ; Anthraquinones/pharmacology* ; DNA Methylation ; Epigenesis, Genetic ; Neoplasms/drug therapy* ; Fibrosis

OBJECTIVE: To investigate the spectrum-effect relationship between the total anthraquinone extract of Cassia seeds and fluorouracil (5-Fu)-induced liver injury in mice and identify the effective components in the extract. METHODS: A mouse model of liver injury was established by intraperitoneal injection of 5-Fu, with bifendate as the positive control. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and myeloperoxidase (MPO), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in the liver tissue were detected to investigate the effect of the total anthraquinone extract of Cassia seeds (0.4, 0.8 and 1.6 g/kg) on liver injury induced by 5-Fu. HPLC fingerprints of 10 batches of the total anthraquinone extracts were established to analyze the spectrum- effectiveness of the extract against 5- Fu- induced liver injury in mice and screen the effective components using the grey correlation method. RESULTS: The 5- Fu- treated mice showed significant differences in liver function parameters from the normal control mice (P < 0.05), suggesting successful modelling. Compared with those in the model group, serum ALT and AST activities were decreased, SOD and T- AOC activities significantly increased, and MPO level was significantly lowered in the mice treated with the total anthraquinone extract (all P < 0.05). HPLC fingerprints of the 31 components in the total anthraquinone extract of Cassia seeds showed good correlations with the potency index of 5-Fu-induced liver injury but with varying correlation strengths. The top 15 components with known correlations included aurantio-obtusina (peak 6), rhein (peak 11), emodin (peak 22), chrysophanol (peak 29) and physcion (peak 30). CONCLUSION The effective components in the total anthraquinone extract of Cassia seeds, including aurantio-obtusina, rhein, emodin, chrysophanol, and physcion, are coordinated to produce protective effects against 5-Fu-induced liver injury in mice.
Animals ; Mice ; Emodin ; Cassia ; Chemical and Drug Induced Liver Injury, Chronic ; Anthraquinones ; Antioxidants ; Fluorouracil/adverse effects* ; Plant Extracts/pharmacology*

Diabetic kidney disease (DKD) is the primary cause of mortality among diabetic patients. With the increasing prevalence of diabetes, it has become a major concern around the world. The therapeutic effect of clinical use of drugs is far from expected, and therapy choices to slow the progression of DKD remain restricted. Therefore, research on new drugs and treatments for DKD has been a hot topic in the medical field. It has been found that rhein has the potential to target the pathogenesis of DKD and has a wide range of pharmacological effects on DKD, such as anti-nephritis, decreasing blood glucose, controlling blood lipids and renal protection. In recent years, the medical value of rhein in the treatment of diabetes, DKD and renal disease has gradually attracted worldwide attention, especially its potential in the treatment of DKD. Currently, DKD can only be treated with medications from a single symptom and are accompanied by adverse effects, while rhein improves DKD with a multi-pathway and multi-target approach. Therefore, this paper reviews the therapeutic effects of rhein on DKD, and proposes solutions to the limitations of rhein itself, in order to provide valuable references for the clinical application of rhein in DKD and the development of new drugs.
Humans ; Diabetic Nephropathies/drug therapy* ; Kidney/pathology* ; Anthraquinones/therapeutic use* ; Diabetes Mellitus

This study aimed to explore the efficacy and mechanism of combined rhein and emodin in the treatment of ulcerative colitis(UC) from the aspects of network pharmacology, animal inflammation improvement and molecular mechanism. Network pharmacology predicted that combined rhein and emodin acted on 52 potential targets, mainly participating in signaling pathways such as cancer, PI3 K/AKT, microRNAs in cancer and apoptosis. PI3 K/AKT signaling pathway has been reported to be closely related to UC, and the optimal candidate pathway for combined therapy. The UC mice model was established by dextran sodium sulfate, and then the modeled mice were randomly divided into control group, model group, rhein group, emodin group, rhein+emodin group and sulfasalazine group. After administration, compared with the conditions in model group, body weight, disease activity index(DAI) score, colon length, TNF-α, IL-6, IL-1β and myeloperoxidase(MPO) of mice in rhein+emodin group were improved(P<0.01); colonic mucosal injury was significantly reduced; the expression of p-PI3 K/PI3 K and p-AKT/AKT proteins were down-regulated(P<0.01). All the above indices were better than those in the rhein/emodin group alone. The Jin's Q-values of the effect of combined rhein and emodin on colon length, TNF-α, IL-6, IL-1β, MPO, p-PI3 K/PI3 K and p-AKT/AKT were all greater than 1.15, which indicated that there was obvious synergistic effect between rhein and emodin. In all, rhein and emodin have synergistic effect in the treatment of UC, and the mechanism may be related to the inhibition of PI3 K/AKT signaling pathway and the down-regulation of proinflammatory factors. They are the new components in the treatment of UC, which is worthy of attention.
Animals ; Anthraquinones ; Colitis, Ulcerative/metabolism* ; Colon ; Disease Models, Animal ; Emodin/pharmacology* ; Interleukin-6/metabolism* ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Rheum ; Tumor Necrosis Factor-alpha/metabolism*

This study aims to establish an ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) method for the determination of emodin-8-O-β-D-glucoside(EG) and its metabolites in plasma, and to investigate the toxicokinetics(TK) behavior of them in rats. To be specific, the TK of EG and its metabolites from the first to the last administration in the repeated dose toxicity study was determined, and the kinetic parameters were calculated. The exposure of EG prototype and metabolites in rat plasma after oral administration of different doses of EG was evaluated. The result showed that the prototype of EG and its metabolites aloe-emodin-8-O-β-D-glucoside, emodin, aloe-emodin, and hydroxyemodin could be detected in rats after oral administration of high-, medium-, and low-dose EG. The area under the curve(AUC) of the prototype and metabolites after the first and last administration was in positive correlation with the dose. The time to the maximum concentration(T_(max)) of EG and metabolites in the three administration groups was <6 h, and the longest in vivo residence time was 12 h. The T_(max) and in vivo residence time of EG were prolonged with the increase in the dose. The metabolites emodin, aloe-emodin, and hydroxyemodin all had two peaks. Both hydroxyemodin and aloe-emodin exhibited increased plasma exposure, slow metabolism, and accumulation in vivo. In addition, aloe-emodin-8-O-β-D-glucoside and emodin disappeared with the increase in dose, suggesting the change of the metabolic pathway of EG in vivo in the case of high-dose administration. The mechanism of high-dose EG in vivo needs to be further explored. This study preliminarily elucidates the TK behavior of EG in rats, which is expected to support clinical drug use.
Animals ; Anthraquinones ; Chromatography, High Pressure Liquid/methods* ; Emodin/toxicity* ; Glucosides/toxicity* ; Mass Spectrometry ; Rats ; Toxicokinetics

The present study aimed to explore the material basis of Rhei Radix et Rhizoma-Coptidis Rhizoma combination in alleviating "bitter-cold" properties based on the supramolecular chemistry of Chinese medicine.Dynamic light scattering and scanning/transmission electron microscopy were used to characterize the morphological characteristics of supramolecules in the decoction of Rhei Radix et Rhizoma and Coptidis Rhizoma.The chemical composition of supramolecules, as well as the dissolution and release processes of supramolecules and the medicinal components of Coptidis Rhizoma decoction, was determined by the high-performance liquid chromatography-mass spectrometry.The differences in "bitter-cold" medicinal properties between Rhei Radix et Rhizoma decoction, Coptidis Rhizoma decoction, and co-decoction were analyzed by sensory evaluation, electronic tongue, mouse diarrhea model, and pathological indicators.The anthraquinones/tannins and alkaloids interacted to form supramolecules with a scale of about 400 nm when Rhei Radix et Rhizoma and Coptidis Rhizoma were decocted together, which delayed the dissolution and release of the active components represented by berberine. Compared with the consequence of single drug administration at 4 g·kg~(-1), the combination of the two drugs at 8 g·kg~(-1) significantly alleviated the "bitter-cold" properties.The effective components interacted to form supramolecules in the co-decoction of Rhei Radix et Rhizoma and Coptidis Rhizoma, which affected the dissolution and release of the effective components of Chinese medicinal decoction, thereby alleviating the "bitter-cold" properties.The findings of this study provide a new idea for revealing the scientific compatibility of Rhei Radix et Rhizoma and Coptidis Rhizoma.
Mice ; Animals ; Drugs, Chinese Herbal/chemistry* ; Medicine, Chinese Traditional ; Rhizome/chemistry* ; Anthraquinones/analysis* ; Chromatography, High Pressure Liquid/methods* ; Antineoplastic Agents

Angucyclines/angucyclinones are a large group of polycyclic aromatic polyketides and their producers are widely distributed in nature. This family of natural products attracts great attention because of their diverse biological activities and unique chemical structures. With the development of synthetic biology and the exploitation of the actinomycetes from previously unexplored environments, angucyclines/angucyclinones-like natural products with new skeletons were continuously discovered, thus enriching the structural diversity of this family. In this review we summarize the new angucyclines/angucyclinones analogues discovered in the last decade (2010-2020) by using different strategies, such as changing cultivation conditions, genetic modification, genome mining, bioactivity-guided compound isolation, and fermentation of actinomycetes from underexplored environments. We also discuss the role of synthetic biology in the discovery and development of new compounds of the angucycline/angucyclinone family.
Anthraquinones ; Biological Products ; Polyketides ; Streptomyces

Rhei Radix et Rhizoma was first recorded in Shennong Ben Cao Jing, with a wide range of pharmacological activities. Autoimmune disease is a kind of disease that damages the tissue structure and function of immune cells and their components due to the impairment of immune tolerance function, including atherosclerosis, multiple sclerosis, gout, rheumatoid arthritis, autoimmune thyroiditis, ulcerative colitis, type 1 diabetes and IgA nephropathy. In recent years, clinical and experimental studies show that Rhei Radix et Rhizoma has potential therapeutic effects on autoimmune diseases. Under the guidance of the theory of traditional Chinese medicine, this paper reviews therapeutic and intervening effects of Rhei Radix et Rhizoma and its main active ingredient anthraquinone on autoimmune diseases. It also puts forward new study directions in view of the existing problems in studies of rhubarb and its anthraquinone, with the aim to provide reference for clinical treatment and scientific studies of effect of Rhei Radix et Rhizomaon autoimmune diseases.
Animals ; Anthraquinones ; Autoimmune Diseases/drug therapy* ; Drugs, Chinese Herbal ; Rheum ; Rhizome

Rhei Radix et Rhizoma is a kind of commonly used Chinese medicinal materials. Due to the overharvesting, the wild resource is endangering. Large market demand caused severely adulterant of commercial Rhei Radix et Rhizoma medicinal materials and decoction pieces. This manuscript reviewed the advances of the original species authentication in the industrial chain of Rhei Radix et Rhizoma during the latest decade, including characteristics and microscopic features, phytochemical analysis on anthraquinones, and molecular authentication based on DNA barcoding. Accordingly, an original species authentication route for the industrial chain of Rhei Radix et Rhizoma was summarized:(1)the identification of seeds and seedlings by DNA barcoding;(2) the selection of high variable sites based on the chloroplast genome;(3)biomonitoring of the Rhei Radix et Rhizoma medicinal materials and decoction pieces by two-dimensional DNA barcode;(4)traceability of Chinese patent medicines by third-generation sequencing. In conclusion, the combination of molecular identification and traditional identification methods provides a new idea for the identification of the original species of Rhei Radix et Rhizoma in the industrial chain and a essential guidance for the research of drug safety and efficacy of Rhei Radix et Rhizoma.
Animals ; Anthraquinones ; Drugs, Chinese Herbal ; Plant Roots ; Rheum ; Rhizome

This study investigated the effect of rhein(RH) on the apoptosis and autophagy of human umbilical vein endothelial cells(HUVECs) induced by hydrogen peroxide(H_2O_2) and its underlying mechanism. The oxidative damage model in HUVECs was established and the cells were divided into different treatment groups. Cell survival rate was detected by MTT assay, apoptosis by Annexin V-FITC/PI double staining and Hoechst 33258 fluorescence staining, autophagy by Ad-mCherry-GFP-LC3 B adenovirus transfection, and protein expression by Western blot. The results showed that RH could protect cells by increasing the cell survival rate in a dose-dependent manner, decreasing the expression of apoptosis-related proteins(Bax and cleaved caspase-3) and the ratio of Bax/Bcl-2, elevating the expression of Bcl-2, up-regulating the expression of microtubule-associated protein 1 light chain 3(LC3)-Ⅱ, and down-regulating the expression of p62. Adenovirus transfection results showed that RH could increase the green and red spots, as well as the yellow spots. However, after the addition of autophagy inhibitor 3-MA, autophagy was reduced and apoptosis was increased. RH could enhance the expression of silent information regulator 2 related enzyme 1(SIRT1). The addition of SIRT1 inhibitor EX-527 reduced the protective effect of RH and cell viability. The addition of 3-MA had no effect on the expression of SIRT1 protein, but the expression of SIRT1 and LC3-Ⅱ proteins decreased and the expression of p62 increased after the addition of EX-527. After RH treatment, the phosphorylation of adenosine monophosphate-activated protein kinase(AMPK) increased, while that of the mechanistic target of rapamycin(mTOR) decreased in a dose-dependent manner. Moreover, this effect could be weakened by the AMPK inhibitor compound C. RH may enhance autophagy through SIRT1/AMPK/mTOR pathway to reduce H_2O_2-induced apoptosis of HUVECs.
Anthraquinones ; Apoptosis ; Autophagy ; Human Umbilical Vein Endothelial Cells ; Humans ; Hydrogen Peroxide ; Signal Transduction