Transcriptomic divergence of the Rheum palmatum complex derived from top-geoherb and non-geoherb areas provides the insights into geoherbalism properties of rhubarb.

Geoherb usually represents high-quality medicinal herbs with better clinical therapeutic effects, and elucidating the geoherbalism is essential for the quality improvement of traditional Chinese Medicine. However, few researches were conducted to clarify the geoherbalism based on a large scale of transcriptomics. In the present study, we compared the transcriptomes of Rheum palmatum complex derived from top-geoherb and non-geoherb areas to show the geoherbalism properties of rhubarb. A total of 412.32 Gb clean reads were obtained with unigene numbers of 100,615 after assembly. Based on the obtained transcriptome datasets, key enzyme-encoding genes involved in the anthraquinones biosynthesis were also obtained. We also found that 21 anthraquinone-related unigenes were differentially expressed between two different groups, and some of these DEGs were correlated to the content accumulation of five free anthraquinones, indicating that the gene expression profiles may promote the geoherbalism formation of rhubarb. In addition, the selective pressure analyses indicated that most paired orthologous genes between these two groups were subject to negative selection, and only a low proportion of orthologs under positive selection were detected. Functional annotation analyses indicated that these positive-selected genes related to the functions such as gene expression, substance transport, stress response and metabolism, indicating that discrepant environment also enhanced the formation of geoherbalism. Our study not only provided insights for the genetic mechanism of geoherbalism of rhubarb, but also laid more genetic cues for the future rhubarb germplasms improvement and utilization.

A chromosome-level genome reveals genome evolution and molecular basis of anthraquinone biosynthesis in Rheum palmatum.

BACKGROUND: Rhubarb is one of common traditional Chinese medicine with a diverse array of therapeutic efficacies. Despite its widespread use, molecular research into rhubarb remains limited, constraining our comprehension of the geoherbalism. RESULTS: We assembled the genome of Rheum palmatum L., one of the source plants of rhubarb, to elucidate its genome evolution and unpack the biosynthetic pathways of its bioactive compounds using a combination of PacBio HiFi, Oxford Nanopore, Illumina, and Hi-C scaffolding approaches. Around 2.8 Gb genome was obtained after assembly with more than 99.9% sequences anchored to 11 pseudochromosomes (scaffold N50 = 259.19 Mb). Transposable elements (TE) with a continuous expansion of long terminal repeat retrotransposons (LTRs) is predominant in genome size, contributing to the genome expansion of R. palmatum. Totally 30,480 genes were predicted to be protein-coding genes with 473 significantly expanded gene families enriched in diverse pathways associated with high-altitude adaptation for this species. Two successive rounds of whole genome duplication event (WGD) shared by Fagopyrum tataricum and R. palmatum were confirmed. We also identified 54 genes involved in anthraquinone biosynthesis and other 97 genes entangled in flavonoid biosynthesis. Notably, RpALS emerged as a compelling candidate gene for the octaketide biosynthesis after the key residual screening. CONCLUSION: Overall, our findings offer not only an enhanced understanding of this remarkable medicinal plant but also pave the way for future innovations in its genetic breeding, molecular design, and functional genomic studies.

Metabolomics analysis reveals the metabolite profiles of Rheum tanguticum grown under different altitudinal gradients.

BACKGROUND: Plant growth and quality are often affected by environmental factors, including geographical location, climate, and soil. In this study, we describe the effect of altitudinal differences on the growth and active ingredients in Rheum tanguticum Maxim. ex Balf. (R. tanguticum), a traditional Chinese medicinal herb known for its laxative properties. RESULTS: The results showed that plants grown at lower altitudes had better growth performances than those in higher altitude areas. The yield varied by 2.45-23.68 times with altitude, reaching a maximum of 102.01 t/ha. In addition, total anthraquinone and total sennoside contents decreased with increasing altitude, whereas total tannins increased with increasing altitude. The total anthraquinone content of the indicator compound reached 5.15% at five experimental sites, which exceeded the Chinese Pharmacopoeia standard by 70.87%. The content of the other two categories of active ingredients reached a maximum value of 0.94% (total sennosides) and 2.65% (total tannins). Redundancy analysis revealed that annual rainfall, annual average temperature, annual sunshine hours, and pH significantly affected growth and active ingredients. Moreover, key metabolites, such as flavonoids, amino acids and their derivatives, phenolic acids, lipids, and terpenes, were differentially expressed between samples from low- and high-altitude cultivation areas. These metabolites were enriched in the flavonoid and flavonol biosynthetic pathway and the monoterpene biosynthetic pathway. CONCLUSIONS: These results suggest that high anthraquinone content was observed in the lowest-latitude cultivation area due to low rainfall and alkaline soil pH. Key metabolites were significantly upregulated in high-latitude cultivation areas. These results provide a scientific basis for quality control and the systematic cultivation of R. tanguticum.

Topical rhubarb charcoal-crosslinked chitosan/silk fibroin sponge scaffold for the repair of diabetic ulcers improves hepatic lipid deposition in db/db mice via the AMPK signalling pathway.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is closely linked to metabolic syndrome, characterised by insulin resistance, hyperglycaemia, abnormal lipid metabolism, and chronic inflammation. Diabetic ulcers (DUs) comprise consequential complications that arise as a result of T2DM. To investigate, db/db mice were used for the disease model. The findings demonstrated that a scaffold made from a combination of rhubarb charcoal-crosslinked chitosan and silk fibroin, designated as RCS/SF, was able to improve the healing process of diabetic wounds in db/db mice. However, previous studies have primarily concentrated on investigating the impacts of the RSC/SF scaffold on wound healing only, while its influence on the entire body has not been fully elucidated. MATERIAL AND METHODS: The silk fibroin/chitosan sponge scaffold containing rhubarb charcoal was fabricated in the present study using a freeze-drying approach. Subsequently, an incision with a diameter of 8 mm was made on the dorsal skin of the mice, and the RCS/SF scaffold was applied directly to the wound for 14 days. Subsequently, the impact of RCS/SF scaffold therapy on hepatic lipid metabolism was assessed through analysis of serum and liver biochemistry, histopathology, quantitative real-time PCR (qRT-PCR), immunohistochemistry, and Western blotting. RESULTS: The use of the RCS/SF scaffold led to an enhancement in the conditions associated with serum glucolipid metabolism in db/db mice. An assessment of hepatic histopathology further confirmed this enhancement. Additionally, the qRT-PCR analysis revealed that treatment with RCS/SF scaffold resulted in the downregulation of genes associated with fatty acid synthesis, fatty acid uptake, triglyceride (TG) synthesis, gluconeogenesis, and inflammatory factors. Moreover, the beneficial effect of the RCS/SF scaffold on oxidative stress was shown by assessing antioxidant enzymes and lipid peroxidation. Additionally, the network pharmacology analysis verified that the adenosine monophosphate-activated protein kinase (AMPK) signalling pathway had a vital function in mitigating non-alcoholic fatty liver disease (NAFLD) by utilizing R. officinale. The measurement of AMPK, sterol regulatory element binding protein 1 (SREBP1), fatty acid synthase (FASN), and acetyl CoA carboxylase (ACC) gene and protein expression provided support for this discovery. Furthermore, the molecular docking investigations revealed a robust affinity between the active components of rhubarb and the downstream targets of AMPK (SREBP1 and FASN). CONCLUSION: By regulating the AMPK signalling pathway, the RCS/SF scaffold applied topically effectively mitigated hepatic lipid accumulation, decreased inflammation, and attenuated oxidative stress. The present study, therefore, emphasises the crucial role of the topical RCS/SF scaffold in regulating hepatic lipid metabolism, thereby confirming the concept of "external and internal reshaping".

Fe(III)/peroxymonosulfate oxidation system for the degradation of rhein, a toxic component abundance in rhubarb residue.

Rhubarb is widely used in health care, but causing a great amount of rhein-containing herbal residue. Rhein with several toxicities might pollute environment, damage ecology and even hazard human health if left untreated. In this study, the degradation effects of bisulfite- (BS) and peroxymonosulfate- (PMS) based oxidation systems on rhein in rhubarb residue were compared and investigated. The effects of BS and PMS with two valence states of ferric ion (Fe) on the degradation of rhein in rhubarb residue were optimized for the selection of optimal oxidation system. The influences of reaction temperature, reaction time and initial pH on the removal of rhein under the optimal oxidation system were evaluated. The chemical profiles of rhubarb residue with and without oxidation process were compared by UPLC-QTOF-MS/MS, and the degradation effects were investigated by PLS-DA and S plot/OPLS-DA analysis. The results manifested that PMS showed relative higher efficiency than BS on the degradation of rhein. Moreover, Fe(III) promoted the degradation effect of PMS, demonstrated that Fe(III)/PMS is the optimal oxidation system to degrade rhein in rhubarb residue. Further studies indicated that the degradation of rhein by the Fe(III)/PMS oxidation system was accelerated with the prolong of reaction time and the elevation of reaction temperature, and also affected by the initial pH. More importantly, Fe(III)/PMS oxidation system could degrade rhein in rhubarb residue completely under the optimal conditions. In conclusion, Fe(III)/PMS oxidation system is a feasible method to treat rhein in rhubarb residue.

Antiepileptic and Neuroprotective Effects of Rheum tanguticum Root Extract on Trimethyltin-Induced Epilepsy and Neurodegeneration: In Vivo and in Silico Analyses.

BACKGROUND: Rheum tanguticum root, cataloged as "Daehwang" in the Korean Pharmacopeia, is rich in various anthraquinones known for their anti-inflammatory and antioxidant properties. Formulations containing Daehwang are traditionally employed for treating neurological conditions. This study aimed to substantiate the antiepileptic and neuroprotective efficacy of R. tanguticum root extract (RTE) against trimethyltin (TMT)-induced epileptic seizures and hippocampal neurodegeneration. METHODS: The constituents of RTE were identified by ultra-performance liquid chromatography (UPLC). Experimental animals were grouped into the following five categories: control, TMT, and three TMT+RTE groups with dosages of 10, 30, and 100 mg/kg. Seizure severity was assessed daily for comparison between the groups. Brain tissue samples were examined to determine the extent of neurodegeneration and neuroinflammation using histological and molecular biology techniques. Network pharmacology analysis involved extracting herbal targets for Daehwang and disease targets for epilepsy from multiple databases. A protein-protein interaction network was built using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and pivotal targets were determined by topological analysis. Enrichment analysis was performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool to elucidate the underlying mechanisms. RESULTS: The RTE formulation was found to contain sennoside A, sennoside B, chrysophanol, emodin, physcion, (+)-catechin, and quercetin-3-O-glucuronoid. RTE effectively inhibited TMT-induced seizures at 10, 30, and 100 mg/kg dosages and attenuated hippocampal neuronal decay and neuroinflammation at 30 and 100 mg/kg dosages. Furthermore, RTE significantly reduced mRNA levels of tumor necrosis factor (TNF-α), glial fibrillary acidic protein (GFAP), and c-fos in hippocampal tissues. Network analysis revealed TNF, Interleukin-1 beta (IL-1ß), Interleukin-6 (IL-6), Protein c-fos (FOS), RAC-alpha serine/threonine-protein kinase (AKT1), and Mammalian target of rapamycin (mTOR) as the core targets. Enrichment analysis demonstrated significant involvement of R. tanguticum components in neurodegeneration (p = 4.35 × 10-5) and TNF signaling pathway (p = 9.94 × 10-5). CONCLUSIONS: The in vivo and in silico analyses performed in this study suggests that RTE can potentially modulate TMT-induced epileptic seizures and neurodegeneration. Therefore, R. tanguticum root is a promising herbal treatment option for antiepileptic and neuroprotective applications.

Exploration of plant metabolomics variation and absorption characteristics of water-extracted Rheum tanguticum and ethanol-extracted Rheum tanguticum by UHPLC-Q-TOF-MS/MS.

BACKGROUND AND OBJECTIVE: The herb Rheum tanguticum (RT), a member of the Polygonaceae family, is listed in the Chinese Pharmacopoeia and has been widely used to treat cardiovascular and gastrointestinal disease. The research aimed to identify the different substances from two kinds of RT extraction methods and the in vivo biotransformation of RT components. METHODS: In this study, by using ultrahigh-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS), we have investigated the metabolomic variation and the in vivo metabolism of RT. A post-acquisition data processing software, PeakView, was applied to an accurate qualitative analysis of the chemical components in RT. RESULTS: Through plant metabolomics analysis, 24 related, differentially expressed metabolites of RT water extract and alcohol extract were obtained. Combined with novel identification strategies and systematic in vivo metabolism analysis, a total of 101 compounds were discovered or tentatively identified in rat serum (including 15 prototype compounds and 86 metabolites). CONCLUSION: In this study, a combination of extraction methods, liquid chromatography-mass spectrometry (LC-MS) technology, and in vivo animal metabolism studies have been established for the screening, identification, and research of chemical active components of natural medicines. LC-MS analysis combined with plant metabolomics was used to study the differential metabolites between different extraction methods of RT. Based on UHPLC-Q-TOF-MS/MS technology, the composition and metabolism of rat plasma before and after RT administration were analysed in vivo, and 15 prototype components and 86 metabolites were detected.

Efficient screening of pancreatic lipase inhibitors from Rheum palmatum by affinity ultrafiltration-high-performance liquid chromatography combined with high-resolution inhibition profiling.

INTRODUCTION: Pancreatic lipase is one of the most important key targets in the treatment of obesity. Inhibition of pancreatic lipase can effectively reduce lipid absorption and treat obesity and other related metabolic disorders. OBJECTIVES: The goal of this study is the efficient screening of pancreatic lipase inhibitors in the root and rhizome of Rheum palmatum using affinity ultrafiltration-high-performance liquid chromatography (AUF-HPLC) combined with high-resolution inhibition profiling (HRIP). METHODS: Potential pancreatic lipase ligands and pancreatic lipase inhibitors in ethyl acetate fraction of R. palmatum were screened using AUF-HPLC and HRIP, respectively. All screened compounds were identified by HPLC- quadrupole time-of-flight (Q-TOF)/MS. Eight compounds were screened out by both AUF-HPLC and HRIP, and six compounds were screened out by either AUF-HPLC or HRIP alone. The pancreatic lipase inhibitory activities of all screened compounds were verified by enzyme inhibition assay and molecular docking. RESULTS: Five new potent pancreatic lipase inhibitors were discovered, namely procyanidin B5 3,3'-di-O-gallate (IC50 = 0.06 ± 0.01 µM), 1,6-di-O-galloyl-2-O-cinnamoyl-ß-D-glucoside (IC50 = 12.83 ± 0.67 µM), 1-O-(1,3,5-trihydroxy)phenyl-2-O-galloyl-6-O-cinnamoyl-ß-D-glucoside (IC50 = 17.84 ± 1.33 µM), 1,2-di-O-galloyl-6-O-cinnamoyl-ß-D-glucoside (IC50 = 18.39 ± 1.52 µM), and 4-(4'-hydroxyphenyl)-2-butanone-4'-O-ß-D-(2"-O-galloyl-6"-O-cinnamoyl)-glucoside (IC50 = 2.91 ± 0.40 µM). It was found that procyanidin B5 3,3'-di-O-gallate showed higher pancreatic lipase inhibitory activity than the positive control orlistat (IC50 = 0.12 ± 0.02 µM). CONCLUSION: The combination of affinity ultrafiltration-high-performance liquid chromatography (AUF-HPLC) and high-resolution inhibition profiling (HRIP) could reduce the risk of false-negative screening and missed screening and could achieve more efficient screening of bioactive compounds in complex natural products.

Rheum khorasanicum. Hydroalcoholic root extract induces cell death in human colorectal adenocarcinoma: An in vitro and in silico study.

Colorectal cancer (CRC) is the second greatest cause of cancer-related death in the world and chemotherapy, as an important part of CRC treatment, has some drawbacks, including systemic toxicity. Therefore, it is crucial to discover new and more effective CRC treatment plans. Rheum khorasanicum (R. khorasanicum) is a medicinal plant with high flavonoids, stilbenes, and anthraquinone contents, so it can be a potential source of antioxidants and can be used for therapeutic purposes and trigger apoptosis in cancer cells. In this study, we investigated the effects of hydroalcoholic root extract of R. khorasanicum treatment on inducing mitochondrial apoptosis of HT-29 and Caco-2 human colorectal adenocarcinoma cells. Firstly, the total phenolic and flavonoid content was determined. Then, the cytotoxic effects of R. khorasanicum on cells of three different types, including HT-29 and Caco-2 colon cancer cells as well as normal 3T3 cells were assessed using the MTT assay. To investigate the characteristics of cellular death, flow cytometry, and western blotting were performed. The results of this study indicated considerable phenolic (356.4±9.4 GAE/gDW) and flavonoid (934.55±17.1 QE/gDW) contents in R. khorasanicum. MTT assay's finding indicated that 100, 60, and 30µg/mL concentrations of R. khorasanicum reduce cell viability in HT-29 and Caco-2 cell lines significantly (P<0.05). It has been also revealed that R. khorasanicum extract induces apoptosis rather than necrosis in these cell lines. Moreover, Bcl-2 expression was significantly reduced in both HT-29 and Caco-2 cell lines, while Bax and cleaved caspase-3 expression soared considerably in the groups under R. khorasanicum treatment (P<0.05). In conclusion, our findings have suggested that high phenol and flavonoid contents of R. khorasanicum root extract possibly play an important role in cell cytotoxicity and apoptosis induction in HT-29 and Caco-2 colon cancer cells.

[Pseudo-targeted metabolomics for differential components of Rhei Radix et Rhizoma from three plant species].

Rhei Radix et Rhizoma is common traditional Chinese medicine with multiple original plants. The content and proportion of the active components in Rhei Radix et Rhizoma from different plant species were compared to accurately evaluate the medicine qua-lity and provide a theoretical basis for precise use of this medicine in clinical practice. In this study, fresh Rhei Radix et Rhizoma samples were collected from the four-year-old plants of Rheum palmatum, R. tanguticum, and R. officinale. The relative content of 220 anthraquinones, anthrones, and tannins in the samples were determined by pseudo-targeted metabolomics, and the differential components were screened by multivariate statistical methods. The principal component analysis classified the samples into three clusters according to the original plants. The orthogonal partial least squares-discriminant analysis(OPLS-DA) screened out 117 differential components, including 8 free anthraquinones, 18 anthraquinone glycosides, 80 anthrones, and 11 tannins. Twenty-eight components had the highest content in R. tanguticum, mainly including sennosides, anthraquinone glycosides, and procyanidins. Thirty-five components showed the highest content in R. officinale, mainly including free anthraquinones and catechines. Fifty-four components showed the highest content in R. palmatum, mainly including dianthrones, while the structures of most of them cannot be determined temporarily. The content distribution of differential components in the three original plants indicates that R. tanguticum has the strongest effect of purging, while R. officinale has the strongest effect of clearing heat and purging fire, and both have stronger effects of resolvong stasis and dredging meridians than R. palmatum.

[UPLC-QE-Orbitrap-MS combined with network pharmacology to explore differential components and mechanisms of raw and scorched rhubarb for treatment of ulcerative colitis].

This study compared the therapeutic difference effects of the raw and scorched rhubarb for the treatment of ulcerative colitis(UC) and explored their difference in chemical components and mechanisms by using ultra-high performance liquid chromatography-quadrupole-electrostatic field orbitrap high-resolution mass spectrometry(UPLC-QE-Orbitrap-MS) and network pharmacology. The UC therapeutic effects of Shaoyao Decoction with the raw rhubarb or the scorched rhubarb were evaluated by dextran sulfate sodium(DSS)-induced mouse model. The results showed that Shaoyao Decoction with either the raw rhubarb or the scorched rhubarb could relieve the UC symptoms of mice to different extents, while the scorched rhubarb-based formula showed advantages in reducing hemorrhagic diarrhea and inflammation levels. UPLC-QE-Orbitrap-MS was used to identify a total of 78 small molecules in the water decoction of the raw and scorched rhubarb. Multivariate statistical methods were used to screen components increasing significantly after the scorching process. The seven compounds included five free anthraquinones, gallic acid, and 5-hydroxymethylfurfural(HMF). Meanwhile, the nine compounds decreasing scorching were mainly combined anthraquinones and catechins-related compounds. Network pharmacology and molecular docking suggested that free anthraquinones, gallic acid, and 5-HMF may act on core targets such as B-cell lymphoma-2(BCL2), epidermal growth factor receptor(EGFR), tumor necrosis factor(TNF), and caspase-3(CASP3) and influence the signaling pathways such as phosphoinositide-3-kinase/protein kinase B(PI3K/Akt), hypoxia inducible factor-1(HIF-1), TNF, and mitogen-activated protein kinase(MAPK), so as to regulate the inflammation response, oxidative stress, and cell apoptosis to relieve UC symptoms. This study compared the therapeutic effects and chemical components of the raw and scorched rhubarb, providing the clinical reference for using rhubarb to treat UC.

[Effect and mechanism of free total rhubarb anthraquinones on pyroptosis of J774A.1 macrophages].

In this study, J774A.1 macrophages stimulated by lipopolysaccharide(LPS) and adenosine triphosphate(ATP) were used to establish an in vitro model of pyroptosis, and the intervention mechanism of free total rhubarb anthraquinones(FTRAs) on pyroptosis was investigated. J774A.1 macrophages were cultured in vitro, and the experiment was assigned to the control group and groups with different concentrations of LPS(0.25, 0.5, and 1 µg·mL~(-1)) and ATP(1.25, 2.5, and 5 mmol·L~(-1)). An in vitro model of macrophage pyroptosis was established by detecting cell viability through CCK-8, propidium iodide(PI) apoptotic cell staining, lactate dehydrogenase(LDH), interleukin(IL)-18, and tumor necrosis factor(TNF)-α release. Then, J774A.1 macrophages were randomly divided into six groups: blank control group, LPS+ATP group, high-dose FTRA group, and low, medium, and high-dose FTRA pre-protection group. The phenotypic characteristics and key indicators of pyroptosis were detected as the basis for evaluating the effect of FTRAs on pyroptosis induced by LPS and ATP. Western blot and RT-PCR were used to detect the expression levels of protein and mRNA related to the pyroptosis pathway in caspase-1/11 and elucidate the molecular mechanism of the anti-pyroptosis effect. The results showed that the stimulation condition of 0.50 µg·mL~(-1) LPS+5.00 mmol·L~(-1) ATP was the most effective in the in vitro model of macrophage pyroptosis. FTRAs pre-protected cells for 24 h and then can increase cell viability under pyroptosis conditions, alleviate cell damage, lower the positive rate of PI staining, and reduce the release of LDH, IL-18, and TNF-α. FTRAs were able to significantly inhibit the activation of GSDMD proteins and significantly down-regulate the protein expression of the pyroptosis pathway signature molecules, TLR4, NLRP3, cleaved-caspase-1, and cleaved-caspase-11, but they had no significant effect on ASC proteins. FTRAs were also able to significantly inhibit the mRNA expression of caspase-1, caspase-11, and GSDMD. These results indicate that FTRAs have an inhibitory effect on the pyroptosis model induced by LPS and ATP and play an anti-pyroptosis effect by regulating classical and non-classical pyroptosis signaling pathways and reducing the production of inflammatory cytokines.

The response of rhubarb to smut infection is revealed through a comparative transcriptome and metabolome study.

MAIN CONCLUSION: Integrated transcriptome and metabolome analysis have unveiled the physiological and molecular responses of rhubarb to infection by smut fungi. Rhubarb is an important medicinal plant that is easily infected by smut fungi during its growth. Thus far, no research on the influence of smut fungi on the growth of rhubarb and its secondary metabolism has been conducted. In this study, petioles of Chinese rhubarb (Rheum officinale) [healthy or infected with smut fungus (Thecaphora schwarzmaniana)] were characterized. Microscopic structure, global gene expression profiling, global metabolic profiling, and key enzyme activity and metabolite levels in infected plants were analyzed. Infection by smut fungi resulted in numerous holes inside the petiole tissue and led to visible tumors on the external surface of the petiole. Through metabolic changes, T. schwarzmaniana induced the production of specific sugars, lipids, and amino acids, and inhibited the metabolism of phenolics and flavonoids in R. officinale. The concentrations of key medicinal compounds (anthraquinones) were decreased because of smut fungus infection. In terms of gene expression, the presence of T. schwarzmaniana led to upregulation of the genes associated with nutrient (sugar, amino acid, etc.) transport and metabolism. The gene expression profiling showed a stimulated cell division activity (the basis of tumor formation). Although plant antioxidative response was enhanced, the plant defense response against pathogen was suppressed by T. schwarzmaniana, as indicated by the expression profiling of genes involved in biotic and abiotic stress-related hormone signaling and the synthesis of plant disease resistance proteins. This study demonstrated physiological and molecular changes in R. officinale under T. schwarzmaniana infection, reflecting the survival tactics employed by smut fungus for parasitizing rhubarb.

The effects of the Rheum ribes plant extract on inflammation, extracellular matrix remodeling, and obesity suggest a therapeutic potential.

BACKGROUND: The prevalence of obesity is increasing in the world, and the Type II diabetes associated with obesity led researchers to seek alternative methods to treat these two chronic diseases. In the case of obesity and diabetes, changes occur in the levels of inflammatory mediators. A study was conducted to investigate the molecular mechanism of the Rheum ribes L. plant regarding obesity and inflammation. METHODS AND RESULTS: Differentiated 3T3-L1 mouse cell lines were used as an experimental model. A dose-response relationship was established to determine at what dose and time of treatment the R. ribes L. plant extract would act effectively. To assess expression on the transcriptional level, q-PCR analyses were performed. The primers to evaluate the expression levels of genes such as Dgat1, Lpl, Fasn, ColV, Il-6, and Mcp1, which are known to be associated with obesity and insulin resistance, inflammation, and cell skeletal restructuring was designed using NCBI sequences. 18S was chosen as the housekeeping gene for normalization. CONCLUSION: It was found that applying 50 µg/mL and 100 µg/mL of R. ribes root extract to 3T3-L1 adipocyte cells for 24 and 48 h resulted in anti- obesity and anti-inflammatory effects on the genes examined at the transcriptional level. It is an effective study to understand the molecular mechanisms by which R. ribes, which is known to have anti-diabetic, anti-obesity and anti- inflammatory activities, and to establish a link between these activities.

Molecular mechanism of Rhubarb in the treatment of non-small cell lung cancer based on network pharmacology and molecular docking technology.

Non-small cell lung cancer (NSCLC) is one of the leading causes of death in the world. Rhubarb, a traditional Chinese medicine, has been widely used in the treatment of inflammatory and autoimmune diseases. This study aimed to investigate the possible mechanism of the rhubarb herb in the treatment of NSCLC by means of network pharmacology and molecular docking and to provide a theoretical basis for experiments and clinical application of traditional Chinese medicine for treating lung cancer. The main active chemical components and targets of rhubarb were screened through Swiss Target Prediction, TargetNet, and Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. The protein-protein interaction (PPI) network was built via an in-depth exploration of the relationships between the proteins. The enrichment analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were applied to predict the potential roles in the pathogenesis of NSCLC via the R package cluster Profiler. Potential targets and active ingredients associated with anti-tumor effects of rhubarb were screened by reverse molecular docking. By searching databases and literature, a total of 295 targets were found for the 21 active ingredients in rhubarb. There were 68 common target genes associated with NSCLC, of which 9 are derived from FDA-approved drugs. GO Gene Set Enrichment Analysis (GSEA) explored up to 1103 biological processes, 62 molecular functions, and 18 cellular components. KEGG GSEA explored 65 basic pathways, and 71 disease pathways. Four key targets (JUN, EGFR, BCL2, and JAK2) were screened through the protein-protein interaction network, target-pathway network, and FDA drug-target network. Molecular docking results showed that these key targets had relatively strong binding activities with rhubarb's active ingredients. The present study explored the potential pharmacological mechanisms of rhubarb on NSCLC, promoting the clinical application of rhubarb in treating NSCLC, and providing references for advanced research.

Determination of rhein and physcion in rhubarb by microchip capillary electrophoresis in mixed hydro-organic solvent combined with laser-induced fluorescence detection.

Microchip capillary electrophoresis in mixed hydro-organic solvent combined with laser-induced fluorescence detection was developed for the separation and detection of physcion and rhein in rhubarb. In contrast to the conventional capillary electrophoresis method, ammonium acetate-dimethyl sulfoxide was used as the basic buffer system in this method. The effects of background buffer, buffer apparent pH*, buffer concentration, water ratio, sample preparation method, and separation voltage on separation and detection were investigated. Optimized separation and detection conditions were obtained: the buffer consisted of 20 mmol/L of ammonium acetate in hydro-organic solvent composed dimethyl sulfoxide, formamide, and water mixed at 60/20/20 (v/v/v) ratio. The separation voltage was 1.9 kV. Under these conditions, the physcion, rhein, and other components of rhubarb can be completely separated within 150 s. Under the methodological verification, good linearity (R ≥ 0.9995) for physcion and rhein, and low limits of detection (0.085 µg·mL-1 and 0.077 µg·mL-1 , respectively), satisfactory peak area precisions, migration time precisions (1.74%-3.09%), and accuracy (recovery rate 97.8% and 101.4%) were achieved. It is shown that the proposed method is simple, efficient, fast, sensitive, simple instrument, consumes few samples, has low operating cost, and is linear.

Phylogenomics, phylogeography and germplasms authentication of the Rheum palmatum complex based on complete chloroplast genomes.

As a traditional Chinese medicine, rhubarb is used to treat several diseases such as severe acute pancreatitis, sepsis and chronic renal failure. However, few studies focused on the authentication of germplasm for the Rheum palmatum complex, and no studies have been conducted to elucidate the evolutionary history of the R. palmatum complex using plastome datasets. Hence, we aim to develop the potential molecular markers to identify the elite germplasms of rhubarb and explore the divergence and biogeographic history of the R. palmatum complex based on the newly sequenced chloroplast genome datasets. Chloroplast genomes of thirty-five the R. palmatum complex germplasms were sequenced, and the length ranged from 160,858 to 161,204 bp. The structure, gene content and gene order were highly conserved across all genomes. Eight InDels and sixty-one SNPs loci could be used to authenticate the high-quality germplasms of rhubarb in specific areas. Phylogenetic analysis revealed that all rhubarb germplasms were clustered in the same clade with high bootstrap support values and Bayesian posterior probabilities. According to the molecular dating result, the intraspecific divergence of the complex occurred in the Quaternary, which might be affected by climatic fluctuation. The biogeography reconstruction indicated that the ancestor of the R. palmatum complex might originate from the Himalaya-Hengduan Mountains or/and Bashan-Qinling Mountains, and then spread to surrounding areas. Several useful molecular markers were developed to identify rhubarb germplasms, and our study will provide further understanding on speciation, divergence and biogeography of the R. palmatum complex.

Soluble Protein Content, Bioactive Compounds and the Antioxidant Activity in Seeds of Ten Rheum tanguticum Lines from Qinghai-Tibet Plateau.

Rheum tanguticum (Rh. tanguticum) is a Chinese medicinal plant traditionally used in the treatment of constipation. As a byproduct, the seeds of this plant are rich in nutrients and phytochemicals. This study aimed to determine and assess seed germination ability, seed physical characteristics, soluble protein content, chemical constituents and antioxidant capacity from different breeding lines, to promote the development and utilization of seed resources. Significant differences were observed for the soluble protein content and antioxidant assays among the ten lines. The contents of aloe-emodin, rhein and catechins accumulated in seeds were extremely low and significantly different from those in roots. In contrast, emodin and chrysophanol were abundant in seeds, and significant differences were observed between seeds and roots. It was found that associations between gallic acid and catechins were not significant for either soluble protein or antioxidant capacity. There was a significantly positive correlation between the contents of four anthraquinones (aloe-emodin, rhein, emodin and chrysophanol) and soluble protein. Seeds have potent antioxidative capacity and relatively high levels of soluble protein content. The rich chemical composition of seeds can be widely used in the medical industry for further development.

In Silico Neuroprotective Effects of Specific Rheum palmatum Metabolites on Parkinson's Disease Targets.

Parkinson's disease (PD) is one of the large-scale health issues detrimental to human quality of life, and current treatments are only focused on neuroprotection and easing symptoms. This study evaluated in silico binding activity and estimated the stability of major metabolites in the roots of R. palmatum (RP) with main protein targets in Parkinson's disease and their ADMET properties. The major metabolites of RP were subjected to molecular docking and QSAR with α-synuclein, monoamine oxidase isoform B, catechol o-methyltransferase, and A2A adenosine receptor. From this, emodin had the greatest binding activity with Parkinson's disease targets. The chemical stability of the selected compounds was estimated using density functional theory analyses. The docked compounds showed good stability for inhibitory action compared to dopamine and levodopa. According to their structure-activity relationship, aloe-emodin, chrysophanol, emodin, and rhein exhibited good inhibitory activity to specific targets. Finally, mediocre pharmacokinetic properties were observed due to unexceptional blood-brain barrier penetration and safety profile. It was revealed that the major metabolites of RP may have good neuroprotective activity as an additional hit for PD drug development. Also, an association between redox-mediating and activities with PD-relevant protein targets was observed, potentially opening discussion on electrochemical mechanisms with biological functions.

Therapeutic Potential of 1,8-Dihydroanthraquinone Derivatives for Breast Cancer.

Breast cancer (BC) is the most common malignancy among women worldwide. In recent years, significant progress has been made in BC therapy. However, serious side effects resulting from the use of standard chemotherapeutic drugs, as well as the phenomenon of multidrug resistance (MDR), limit the effectiveness of approved therapies. Advanced research in the BC area is necessary to create more effective and safer forms of therapy to improve the outlook for individuals diagnosed with this aggressive neoplasm. For decades, plants and natural products with anticancer properties have been successfully utilized in treating various medical conditions. Anthraquinone derivatives are tricyclic secondary metabolites of natural origin that have been identified in plants, lichens, and fungi. They represent a few botanical families, e.g., Rhamnaceae, Rubiaceae, Fabaceae, Polygonaceae, and others. The review comprehensively covers and analyzes the most recent advances in the anticancer activity of 1,8-dihydroanthraquinone derivatives (emodin, aloe-emodin, hypericin, chrysophanol, rhein, and physcion) applied both individually, or in combination with other chemotherapeutic agents, in in vitro and in vivo BC models. The application of nanoparticles for in vitro and in vivo evidence in the context of 1,8-dihydroanthraquinone derivatives was also described.