The Roles of the Anthraquinone Parietin in the Tolerance to Desiccation of the Lichen Xanthoria parietina: Physiology and Anatomy of the Pale and Bright-Orange Thalli.

Lichens are symbiotic organisms that effectively survive in harsh environments, including arid regions. Maintaining viability with an almost complete loss of water and the rapid restoration of metabolism during rehydration distinguishes lichens from most eukaryotic organisms. The lichen Xanthoria parietina is known to have high stress tolerance, possessing diverse defense mechanisms, including the presence of the bright-orange pigment parietin. While several studies have demonstrated the photoprotective and antioxidant properties of this anthraquinone, the role of parietin in the tolerance of lichens to desiccation is not clear yet. Thalli, which are exposed to solar radiation and become bright orange, may require enhanced desiccation tolerance. Here, we showed differences in the anatomy of naturally pale and bright-orange thalli of X. parietina and visualized parietin crystals on the surface of the upper cortex. Parietin was extracted from bright-orange thalli by acetone rinsing and quantified using HPLC. Although acetone rinsing did not affect PSII activity, thalli without parietin had higher levels of lipid peroxidation and a lower membrane stability index in response to desiccation. Furthermore, highly pigmented thalli possess thicker cell walls and, according to thermogravimetric analysis, higher water-holding capacities than pale thalli. Thus, parietin may play a role in desiccation tolerance by stabilizing mycobiont membranes, providing an antioxidative defense, and changing the morphology of the upper cortex of X. parietina.

Elucidation of inhibitory effects of bioactive anthraquinones towards formation of DNA advanced glycation end products (DNA-AGEs).

DNA is essential in biological processes as it directs transcription and translation assisting in RNA and protein synthesis. Extended periods of elevated blood glucose levels cause non-enzymatic DNA glycation, which results in the formation of DNA-AGEs and the production of free radicals, causing structural perturbation of DNA. In this work, we have investigated the glycation of calf thymus (ct-DNA) DNA and examined its inhibition by two anthraquinone derivatives, purpurin and aloin. Ribose sugar served as the glycating agent inducing non-enzymatic glycation of DNA and subsequent DNA-AGEs formation. UV-vis and fluorescence spectroscopic methods were utilized to characterize DNA-AGE formation in vitro. Circular dichroism (CD) spectroscopy was used to observe the structural disruption of DNA caused by glycation. The changes in AGEs fluorescence intensity and melting temperature (Tm) were measured to assess the inhibition of glycation process by aloin and purpurin. These derivatives demonstrated inhibitory effects via binding to glycating sites of ct-DNA or by scavenging free radicals generated during glycation. The current study elucidates the inhibitory actions of aloin and purpurin on DNA glycation, suggesting their possible applications in mitigating the adverse consequences linked to increased ribose concentrations.

Effects of Fermented Polygonum cuspidatum on the Skeletal Muscle Functions.

Plant extract fermentation is widely employed to enhance the nutritional and pharmaceutical value of functional foods. Polygonum cuspidatum (Pc) contains flavonoids, anthraquinones, and stilbenes, imparting protective effects against inflammatory diseases, cancer, diabetes, and cardiovascular diseases. However, the effects of fermented Pc on skeletal muscle strength remain unexplored. In this study, we generated fermented Pc using a complex of microorganisms containing Lactobacillus spp. (McPc) and assessed its effects on muscle strength and motor function in mice. Compared to unfermented Pc water extract, elevated levels of emodin and resveratrol were noted in McPc. This was identified and quantified using UPLC-QTOF/MS and HPLC techniques. Gene expression profiling through RNA-seq and quantitative RT-PCR revealed that McPc administration upregulated the expression of genes associated with antioxidants, glycolysis, oxidative phosphorylation, fatty acid oxidation, and mitochondrial biogenesis in cultured C2C12 myotubes and the gastrocnemius muscle in mice. McPc significantly improved skeletal muscle strength, motor coordination, and traction force in mice subjected to sciatic neurectomy and high-fat diet (HFD). McPc administration exhibited more pronounced improvement of obesity, hyperglycemia, fatty liver, and hyperlipidemia in HFD mice compared to control group. These findings support the notion that emodin and resveratrol-enriched McPc may offer health benefits for addressing skeletal muscle weakness.

Trichoderma-derived emodin competes with ExpR and ExpI of Pectobacterium carotovorum subsp. carotovorum to biocontrol bacterial soft rot.

BACKGROUND: Quorum sensing inhibitors (QSIs) are an emerging control tool that inhibits the quorum sensing (QS) system of pathogenic bacteria. We aimed to screen for potential QSIs in the metabolites of Trichoderma and to explore their inhibitory mechanisms. RESULTS: We screened a strain of Trichoderma asperellum LN004, which demonstrated the ability to inhibit the color development of Chromobacterium subtsugae CV026, primarily attributed to the presence of emodin as its key QSI component. The quantitative polymerase chain reaction with reverse transcription results showed that after emodin treatment of Pectobacterium carotovorum subsp. carotovorum (Pcc), plant cell wall degrading enzyme-related synthetic genes were significantly downregulated, and the exogenous enzyme synthesis gene negative regulator (rsmA) was upregulated 3.5-fold. Docking simulations indicated that emodin could be a potential ligand for ExpI and ExpR proteins because it exhibited stronger competition than the natural ligands in Pcc. In addition, western blotting showed that emodin attenuated the degradation of n-acylhomoserine lactone on the ExpR protein and protected it. Different concentrations of emodin reduced the activity of pectinase, cellulase, and protease in Pcc by 20.81%-72.21%, 8.38%-52.73%, and 3.57%-47.50%. Lesion size in Chinese cabbages, carrots and cherry tomatoes following Pcc infestation was reduced by 10.02%-68.57%, 40.17%-88.56% and 11.36%-86.17%. CONCLUSION: Emodin from T. asperellum LN004 as a QSI can compete to bind both ExpI and ExpR proteins, interfering with the QS of Pcc and reducing the production of virulence factors. The first molecular mechanism reveals the ability of emodin as a QSI to competitively inhibit two QS proteins simultaneously. © 2023 Society of Chemical Industry.

Emodin exhibits anti-acne potential by inhibiting cell growth, lipogenesis, and inflammation in human SZ95 sebocytes.

Emodin, a natural anthraquinone derivative, possesses anti-proliferative and anti-inflammatory properties in skin diseases. However, little information is available on the efficacy of emodin in treating acne vulgaris (acne). This study aims to investigate the protective effects and potential mechanisms of emodin as an anti-acne agent. In vitro, SZ95 sebocytes was chose to establish an acneigenic cellular model. We found that emodin effectively inhibited proliferation, induced cell cycle arrest and apoptosis of SZ95 sebocytes in a dose-dependent manner. To evaluate the lipid-lowering potential of emodin, we examined the levels of lipid contents and lipogenic transcription factors, and found that both lipid production and protein expression of PPARγ, LXR α/ß, and SREBP-1 were decreased after treatment with emodin. Furthermore, our results revealed that emodin inhibited sebaceous lipogenesis induced by insulin-like growth factor 1 (IGF-1), which was accompanied by a potent inhibition of the phosphoinositide-3-kinase (PI3K)/Akt/forkhead box protein O1 (FoxO1) pathway. In detail, emodin augmented the inhibitory effect of isotretinoin and PI3K inhibitor LY294002, while attenuating the activation of IGF-1 on PI3K/Akt/FoxO1 pathway. In addition, emodin could decrease the secretion of pro-inflammatory cytokines IL-6 and IL-8, and suppress the expression of NLRP3, capase-1, IL-1ß, and IL-18 in SZ95 sebocytes exposed to Cutibacterium acnes. Overall, our study provides preliminary evidence supporting the anti-growth, anti-lipogenic and anti-inflammatory properties of emodin, indicating the potential therapeutic application of emodin for acne treatment.

Emodin reduces surgical wounding-accelerated tumor growth and metastasis via macrophage suppression in a murine triple-negative breast cancer model.

It has been suspected that tumor resection surgery itself may accelerate breast cancer (BC) lung metastasis in some patients. Emodin, a natural anthraquinone found in the roots and rhizomes of various plants, exhibits anticancer activity. We examined the perioperative use of emodin in our established surgery wounding murine BC model. Emodin reduced primary BC tumor growth and metastasis in the lungs in both sham and surgical wounded mice, consistent with a reduction in proliferation and enhanced apoptosis (primary tumor and lungs). Further, emodin reduced systemic inflammation, most notably the number of monocytes in the peripheral blood and reduced pro-tumoral M2 macrophages in the primary tumor and the lungs. Consistently, we show that emodin reduces gene expression of select macrophage markers and associated cytokines in the primary tumor and lungs of wounded mice. Overall, we demonstrate that emodin is beneficial in mitigating surgical wounding accelerated lung metastasis in a model of triple-negative BC, which appears to be mediated, at least in part, by its actions on macrophages. These data support the development of emodin as a safe, low-cost, and effective agent to be used perioperatively to alleviate the surgery triggered inflammatory response and consequential metastasis of BC to the lungs.

Emodin alleviates chronic constriction injury-induced neuropathic pain and inflammation via modulating PPAR-gamma pathway.

Neuropathic pain has been characterized as chronic pain resulting from pathological damage to the sensorimotor system. Because of its complex nature, it remains refractory to most of the therapeutic interventions, and surgical intervention and physiotherapy alongside steroidal treatments remain the only treatment protocols with limited success, hence solidifying the need to find efficacious therapeutic alternatives. Emodin was used as a post-treatment for its potential to be neuroprotective in the treatment of chronic constriction injury-induced NP. The first day following surgery, Emodin treatment began, and it lasted until the 21st day. On days 3, 7, 14 and 21, all behavioral investigations were conducted. The sciatic nerve and spinal cord were extracted for further molecular examination. Emodin elevated response latency, was able to delay the onset of mechanical hyperalgesia in rats on days 7, 14, and 21 and reduced the CCI-induced paw deformation. Emodin treatment significantly reduced lipid peroxidation and NO levels while restoring the GST, GSH and catalase. It significantly improved the disorientation of the sciatic nerve and spinal cord confirmed by H & E staining and reduced inflammatory markers as observed by the quantification of COX-2, TNF-α, p-NFκb and up-regulated PPAR-γ levels by ELISA and PCR. According to the findings, Emodin has antinociceptive and anti-hyperalgesic properties, which reduced pain perception and inflammation. We also suggested the involvement of PPAR-γ pathway in the therapeutic potential of emodin in chronic nerve injury.

Emodin promotes hepatic stellate cell senescence and alleviates liver fibrosis via a nuclear receptor (Nur77)-mediated epigenetic regulation of glutaminase 1.

BACKGROUND AND PURPOSE: Senescence in hepatic stellate cells (HSCs) limits liver fibrosis. Glutaminolysis promotes HSC activation. Here, we investigated how emodin affected HSC senescence involving glutaminolysis. EXPERIMENTAL APPROACH: Senescence, glutaminolysis metabolites, Nur77 nuclear translocation, glutaminase 1 (GLS1) promoter methylation and related signalling pathways were examined in human HSC-LX2 cells using multiple cellular and molecular approaches. Fibrotic mice with shRNA-mediated knockdown of Nur77 were treated with emodin-vitamin A liposome for investigating the mechanisms in vivo. Human fibrotic liver samples were examined to verify the clinical relevance. KEY RESULTS: Emodin upregulated several key markers of senescence and inhibited glutaminolysis cascade in HSCs. Emodin promoted Nur77 nuclear translocation, and knockdown of Nur77 abolished emodin blockade of glutaminolysis and induction of HSC senescence. Mechanistically, emodin facilitated Nur77/DNMT3b interaction and increased GLS1 promoter methylation, leading to inhibited GLS1 expression and blockade of glutaminolysis. Moreover, the glutaminolysis intermediate α-ketoglutarate promoted extracellular signal-regulated kinase (ERK) phosphorylation, which in turn phosphorylated Nur77 and reduced its interaction with DNMT3b. This led to decreased GLS1 promoter methylation and increased GLS1 expression, forming an ERK/Nur77/glutaminolysis positive feedback loop. However, emodin repressed ERK phosphorylation and interrupted the feedback cascade, stimulating senescence in HSCs. Studies in mice showed that emodin-vitamin A liposome inhibited glutaminolysis and induced senescence in HSCs, and consequently alleviated liver fibrosis; but knockdown of Nur77 abrogated these beneficial effects. Similar alterations were validated in human fibrotic liver tissues. CONCLUSIONS AND IMPLICATIONS: Emodin stimulated HSC senescence through interruption of glutaminolysis. HSC-targeted delivery of emodin represented a therapeutic option for liver fibrosis.

Aloe-emodin alleviates doxorubicin-induced cardiotoxicity via inhibition of ferroptosis.

Aloe-emodin (AE), a novel ferroptosis inhibitor, alleviates the doxorubicin (DOX)-induced cardiotoxicity in H9c2 rat cardiomyocytes. The inhibition of ferroptosis and the protective effect against cardiotoxicity were evaluated via MTT assay in H9c2 cells. The molecular mechanism of action (MOA) of nuclear factor erythroid 2-related factor 2 (Nrf2) activation, including transactivation of multiple downstream cytoprotective genes, were further assessed by Western blot, luciferase reporter assay and qRT-PCR analyses. Fluorescent imaging was performed to detect the change of intracellular reactive oxygen species, mitochondrial membrane potential and lipid peroxidation. In addition, an infrared spectroscopy was employed to detect the AE-Fe (II) complex. AE, alleviates oxidative stress in DOX-induced H9c2 cells by activating Nrf2 and increasing the expression of Nrf2 downstream antioxidant genes, SLC7A11 and GPX4. Furthermore, AE complexes bivalent iron and regulates the intracellular iron-related genes. In conclusion, the discovery of AE as a novel ferroptosis inhibitor and its MOA provides a new perspective for further exploration of cardio-protective agents in cancer patients during chemotherapy.

Emodin and rhapontigenin inhibit the replication of African swine fever virus by interfering with virus entry.

Africa swine fever (ASF) is a highly pathogenic contagion caused by African swine fever virus (ASFV), which not only affects the development of domestic pig industry, but also causes huge losses to the world agricultural economy. Vaccine development targeting ASFV remains elusive, which leads to severe difficulties in disease prevention and control. Emodin (EM) and rhapontigenin (RHAG), which are extracted from the dried rhizome of Polygonum knotweed, have various biological properties such as anti-neoplastic and anti-bacterial activities, but no studies have reported that they have anti-ASFV effects. This study discovered that EM and RHAG at different concentrations had a significant dose-dependent inhibitory effect on the ASFV GZ201801 strain in porcine alveolar macrophages (PAMs), and at the specified concentration, EM and RHAG showed continuous inhibition at 24 h, 48 h and 72 h. Not only did they strongly impact virion attachment and internalization, but also inhibit the early stages of ASFV replication. Further research proved that the expression level of Rab 7 protein was reduced by EM and RHAG, and treatments with EM and RHAG induced the accumulation of free cholesterol in endosomes and inhibited endosomal acidification, which prevented the virus from escaping and shelling from late endosomes. This study summarized the application of EM and RHAG in inhibiting ASFV replication in-vitro. Similarly, EM and RHAG targeted Rab 7 in the viral endocytosis pathway, inhibited viral infection, and induced the accumulation of cholesterol in the endosomes and the acidification of the endosomes to inhibit uncoating. A reference could be made to the results of this study when developing antiviral drugs and vaccines.

A novel small molecule AdipoR2 agonist ameliorates experimental hepatic steatosis in hamsters and mice.

Adiponectin receptor 2 (AdipoR2) can be activated by its endogenous ligand adiponectin to reduce hepatic steatosis, and is regarded as a therapeutic target for metabolic associated fatty liver disease (MAFLD). This study proposes a novel anthraquinone compound, emodin succinate monoethyl ester (ESME), which activates AdipoR2, inhibits hepatic lipogenesis, promotes fatty acid oxidation, and alleviates experimental hepatic steatosis in hamsters and mice. Molecular docking shows that ESME has strong binding potential with AdipoR2 by forming a arene-arene interaction. AdipoR2 on the cytomembrane of HepG2 cells can be labeled by fluorescent ESME (Cy5-ESME). ESME activates AdipoR2, AMPK and PPARα, and reduces lipid deposition in palmitic acid or oleic acid-induced HepG2 and L02 cells. Suppression of AdipoR2 expression or AMPK activation completely eliminates the effect of ESME on reducing lipid accumulation in hepatocytes. Oral administration of ESME reduces liver lipid production and accumulation, and alleviates hepatic steatosis in hamsters and Apoe-/- mice induced by high-fat diet. Compared with statins and emodin, ESME showed prepotent efficacy and safety in reducing hepatic steatosis and protecting hepatocytes. Furthermore, ESME activates CaMKK2 and LKB1 in liver to activate AMPK and reduce lipogenesis through stimulating AdipoR2. Taken together, ESME reduces hepatic lipid accumulation and alleviates hepatic steatosis by agonizing AdipoR2. ESME is a promising new agent for clinical treatment of MAFLD.

Impact of dry-off and lyophilized Aloe arborescens supplementation on plasma metabolome of dairy cows.

Positive effects have been observed as a result of Aloe arborescens supplementation in the dry-off phase in dairy cows. Metabolomic approaches can provide additional information about animal physiology. Thus, we characterized plasma metabolome around dry-off in 12 cows supplemented (AL) or not (CTR) with 10 g/d of lyophilized A. arborescens with an untargeted metabolomic approach. Overall, 1658 mass features were annotated. Regardless of treatment, multivariate statistics discriminated samples taken before and after dry-off. Overall, 490 metabolites were different between late lactation and early dry period, of which 237 were shared between AL and CTR. The most discriminant compounds (pentosidine and luteolin 7-O-glucoside) were related to the more fibrous diet. Pathway analysis indicated that pyrimidine and glycerophospholipid metabolisms were down-accumulated, suggesting reduced rumen microbial activity and liver load. Samples from AL were discriminated from CTR either the day of dry-off or 7 days after. At dry-off, aloin and emodin were the most discriminant metabolites, indicating that Aloe's bioactive compounds were absorbed. Seven days later, 534 compounds were different between groups, and emodin was among the most impacted. Pathway analysis highlighted that glycerophospholipid, pyrimidine, and folate metabolisms were affected. These results might indicate that Aloe has positive effects on liver function and a modulatory effect on rumen fermentation.

Mining an O-methyltransferase for de novo biosynthesis of physcion in Aspergillus nidulans.

Physcion is one of natural anthraquinones, registered as a novel plant-derived fungicide due to its excellent prevention of plant disease. However, the current production of physcion via plant extraction limits its yield promotion and application. Here, a pair of polyketide synthases (PKS) in emodin biosynthesis were used as probes to mining the potential O-methyltransferase (OMT) responsible for physcion biosynthesis. Further refinement using the phylogenetic analysis of the mined OMTs revealed a distinct OMT (AcOMT) with the ability of transferring a methyl group to C-6 hydroxyl of emodin to form physcion. Through introducing AcOMT, we successfully obtained the de novo production of physcion in Aspergillus nidulans. The physcion biosynthetic pathway was further rationally engineered by expressing the decarboxylase genes from different fungi. Finally, the titer of physcion reached to 64.6 mg/L in shake-flask fermentation through enhancing S-adenosylmethionine supply. Our work provides a native O-methyltransferase for physcion biosynthesis and lays the foundation for further improving the production of physcion via a sustainable route. KEY POINTS: • Genome mining of the native O-methyltransferase responsible for physcion biosynthesis • De novo biosynthesis of physcion in the engineered Aspergillus nidulans • Providing an alternative way to produce plant-derived fungicide physcion.

Emodin protects against apoptosis and inflammation by regulating reactive oxygen species-mediated NF-κB signaling in interleukin-1ß-stimulated human nucleus pulposus cells.

Intervertebral disc degeneration (IDD) is a complex degradative disorder associated with inflammation. Emodin, an anthraquinone derivative, possesses strong anti-inflammatory activity. This study focused on the in vitro therapeutic action of emodin in a cellular model of IDD. Human nucleus pulposus cells (NPCs) were stimulated with interleukin-1ß (IL-1ß) to induce inflammation. Cell Counting Kit-8 and terminal deoxynucleotidyl transferase dUTP nick end labeling staining assays were performed to evaluate the viability and apoptosis of NPCs, respectively. Caspase-3 activity was measured to indirectly assess cell apoptosis. Western blot analysis was performed to detect protein expression levels. Reverse transcription-polymerase chain reaction was performed for the detection of relative mRNA levels of tumor necrosis factor-α (TNF-α) and IL-6. Enzyme-linked immunosorbent assay was performed to analyze TNF-α and IL-6 secretion. Our results showed that emodin treatment mitigated IL-1ß-induced reduction of cell viability in NPCs. Moreover, the increase in reactive oxygen species (ROS) production, apoptotic rate, and caspase-3 activity in IL-1ß-stimulated NPCs was reduced by emodin treatment. Treatment with emodin also abolished IL-1ß-induced inflammation in NPCs, as indicated by reduced secretion of IL-6 and TNF-α. Besides, the increase in expression levels of phosphorylated p65 and nuclear p65 in IL-1ß-stimulated NPCs was suppressed by emodin treatment. Furthermore, inhibition of nuclear factor kappa B (NF-κB) activation with pyrrolidine dithiocarbamate aggravated the protective effects of emodin. These results suggested that emodin protected NPCs against IL-1ß-induced apoptosis and inflammation via inhibiting ROS-mediated activation of NF-κB.

Effects of Emodin on Protein Expression Related to Autophagy of Interstitial Cells of Cajal in Diabetic Rats.

This work aims to investigate the effects and mechanism of emodin in treating diabetic gastroenteropathy and colonic dysmotility in STZ + HS/HF diet induced diabetic gastroenteropathy rats. Diabetic colonic dysmotility model was established by high-fat/high-glucose (HS/HF) feeding combined with streptozotocin (STZ). Emodin was divided into high, medium and low dose groups. After eight weeks of intervention, fasting blood glucose (FBG) and body weight were measured. Gastrointestinal transmission time was evaluated. Serum vasoactive intestinal peptide (VIP) and substance P (SP) were detected. Colonic protein expression of selective autophagy adaptor proteins p62 and beclin1 were detected by immunohistochemistry. Colonic protein expression of beclin1, autophagy related gene 5 (Atg5), C-kit and p62 were detected by Western blot. After treating with emodin, gastrointestinal transmission rate was improved. The expression of serum SP was increased and serum VIP was decreased. Colonic c-kit and p62 were up-regulated. The expressions of beclin1 and Atg5 were down-regulated. Emodin can improve colonic dysmotility and promote the recovery of colonic motility and intestinal defecation in diabetic rats. Its mechanism may involved with up-regulating the expression of C-kit and P62, down-regulating the expression of Beclin1 and Atg5 in colon, which are associated with colon over-autophagy of Cajal interstitial cell (ICC).

The 'emodin family' of fungal natural products-amalgamating a century of research with recent genomics-based advances.

Covering: up to 2022A very large group of biosynthetically linked fungal secondary metabolites are formed via the key intermediate emodin and its corresponding anthrone. The group includes anthraquinones such as chrysophanol and cladofulvin, the grisandienes geodin and trypacidin, the diphenyl ether pestheic acid, benzophenones such as monodictyphenone and various xanthones including the prenylated shamixanthones, the agnestins and dimeric xanthones such as the ergochromes, cryptosporioptides and neosartorin. Such compounds exhibit a wide range of bioactivities and as such have been utilised in traditional medicine for centuries, as well as garnering more recent interest from the pharmaceutical sector. Additional interest comes from industries such as textiles and cosmetics due to their use as natural colourants. A variety of biosynthetic routes and mechanisms have been proposed for this family of compounds, being altered and updated as new biosynthetic methods develop and new results emerge. After nearly 100 years of such research, this review aims to provide a comprehensive overview of what is currently known about the biosynthesis of this important family, amalgamating the early chemical and biosynthetic studies with the more recent genetics-based advances and comparative bioinformatics.

Chemical composition-based characterization of the anti-allergic effect of Guominkang Formula on IgE-mediated mast cells activation and passive cutaneous anaphylaxis.

Guominkang (GMK), a Chinese medicine formula, has been used to treat allergic diseases in clinical settings for many years. To evaluate the antiallergic effect and molecular mechanism of action of GMK extract, RBL-2H3 cell models and passive cutaneous anaphylaxis (PCA) mouse models were established. High performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) analyses were performed to characterize the chemical composition of GMK. A total of 94 compounds were identified or tentatively identified from GMK. Three of them, emodin, ursolic acid, and hamaudol, were identified for the first time as potential active compounds in GMK, since they inhibited the degranulation of mast cells. The anti-allergic effect of hamaudol was the first to be discovered. GMK could markedly mitigate the shade of Evans Blue extravasation and ear incrassation in PCA mouse models. Additionally, GMK significantly inhibited the degranulation of mast cells, suppressed mast cell degranulation by reducing Ca2+ influx and the levels of TNF-α, IL-4, and histamine, and markedly inhibited the phosphorylation of Lyn, Syk, PLCγ1, IκBα, and NF-κB p65. Molecular docking results indicated that hamaudol and emodin had strong interaction with FcɛRI and NF-κB related proteins, while ursolic acid only interacted with NF-κB associated proteins. These results suggest GMK suppresses the activation of MCs both in vivo and in vitro. The underlying mechanism of its anti-allergic activity is associated with the inhibition of FcɛRI and NF-κB activation.

Phytochemistry, Bioactivities of Metabolites, and Traditional Uses of Fagopyrum tataricum.

In Tartary buckwheat (Fagopyrum tataricum), the edible parts are mainly grain and sprouts. Tartary buckwheat contains protecting substances, which make it possible for plants to survive on high altitudes and under strong natural ultraviolet radiation. The diversity and high content of phenolic substances are important for Tartary buckwheat to grow and reproduce under unfriendly environmental effects, diseases, and grazing. These substances are mainly flavonoids (rutin, quercetin, quercitrin, vitexin, catechin, epicatechin and epicatechin gallate), phenolic acids, fagopyrins, and emodin. Synthesis of protecting substances depends on genetic layout and on the environmental conditions, mainly UV radiation and temperature. Flavonoids and their glycosides are among Tartary buckwheat plants bioactive metabolites. Flavonoids are compounds of special interest due to their antioxidant properties and potential in preventing tiredness, diabetes mellitus, oxidative stress, and neurodegenerative disorders such as Parkinson's disease. During the processing and production of food items, Tartary buckwheat metabolites are subjected to molecular transformations. The main Tartary buckwheat traditional food products are bread, groats, and sprouts.

Metabolic profiling of emodin drug-induced liver injury and silybin treatment in rats using ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry: A metabolomic and mechanistic approach.

Silybin, an active component in the plant Silybum marianum (L.) Gaertn., is commonly used to protect against liver disease. We investigated silybin's protective potential in rat liver against emodin-induced liver injury 4 weeks. It was found that aspartate aminotransferase and direct bilirubin serum biomarkers for liver toxicity significantly increased, and liver histopathology revealed cholestasis and necrosis in rats administered emodin alone, whereas aspartate aminotransferase and total bile acid levels in rats administered emodin and silybin simultaneously were changed compared to rats administered emodin alone. Liver mRNA and protein levels of Cyp7a1-which plays roles in cholesterol metabolism and bile acid synthesis-and Abcb11 (Bsep)-which facilitates bile salt secretion in hepatocyte canaliculi-were significantly altered with emodin, whereas cotreatment with silybin attenuated emodin's adverse effect. Metabolomic analysis using ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry determined eight potential metabolite biomarkers in serum, urine, and liver tissue. Network analysis was conducted to conceptualize the interplay of genes, metabolites, and metabolic pathways for cholesterol metabolism and bile acid synthesis for liver injury. Overall, rats administered only emodin were shown to be a sound model to investigate fat-associated drug-induced hepatoxicity or liver injury and cotreatment of emodin with silybin prevents fatty liver injury. This metabolomic study revealed that emodin-induced fatty liver injury disrupted bile acid synthesis, vitamin B6 , and glycerophospholipid metabolism pathways and that silybin ameliorates liver injury on these compromised pathways.

Emodin suppresses hepatocellular carcinoma growth by regulating macrophage polarization via microRNA-26a/transforming growth factor beta 1/protein kinase B.

Accumulating evidence has demonstrated that M2 macrophages contribute to the progression of hepatocellular carcinoma (HCC). Emodin is an anti-tumor agent and potentially regulates macrophage polarization. This study aims to explore the effect of emodin on M2 polarization in HCC and its underlying mechanism. After co-culture systems of M2 macrophages and HCC (HepG2 and Huh7) cells were established, it was shown that co-culture with M2 macrophages could promote both the proliferation and invasion of HepG2 and Huh7 cells. Emodin induces the transformation of M2 to M1 macrophages, thereby inhibiting the proliferation and invasion of HepG2 and Huh7 cells mediated by co-culturing with M2 macrophages. Based on bioinformatics analysis and in vitro validation, it was found that the effect of emodin on M2 polarization was regulated by the microRNA-26a (miR-26)/Transforming growth factor beta 1 (TGF-ß1)/Protein kinase B (Akt) axis. In vivo analysis showed that co-culturing with M2 macrophages markedly facilitated the growth of HepG2 cells, which was significantly inhibited by emodin. Western blot analysis on xenografts confirmed that emodin could induce transformation of M2 to M1 macrophages and reverse the up-regulation of PCNA, TGF-ß1, and p-Akt induced by M2 macrophages. In summary, our findings uncover a novel mechanism behind the anti-tumor effects of emodin that regulates M2 polarization via miR-26a/TGF-ß1/Akt to suppress HCC growth.