The haplotype-resolved genome assembly of autotetraploid rhubarb Rheum officinale provides insights into its genome evolution and massive accumulation of anthraquinones.

Rheum officinale, a member of the Polygonaceae family, is an important medicinal plant that is widely used in traditional Chinese medicine. Here, we report a 7.68-Gb chromosome-scale assembly of R. officinale with a contig N50 of 3.47 Mb, which was clustered into 44 chromosomes across four homologous groups. Comparative genomics analysis revealed that transposable elements have made a significant contribution to its genome evolution, gene copy number variation, and gene regulation and expression, particularly of genes involved in metabolite biosynthesis, stress resistance, and root development. We placed the recent autotetraploidization of R. officinale at ∼0.58 mya and analyzed the genomic features of its homologous chromosomes. Although no dominant monoploid genomes were observed at the overall expression level, numerous allele-differentially-expressed genes were identified, mainly with different transposable element insertions in their regulatory regions, suggesting that they functionally diverged after polyploidization. Combining genomics, transcriptomics, and metabolomics, we explored the contributions of gene family amplification and tetraploidization to the abundant anthraquinone production of R. officinale, as well as gene expression patterns and differences in anthraquinone content among tissues. Our report offers unprecedented genomic resources for fundamental research on the autopolyploid herb R. officinale and guidance for polyploid breeding of herbs.

Comparative Transcriptome Analyses of Different Rheum officinale Tissues Reveal Differentially Expressed Genes Associated with Anthraquinone, Catechin, and Gallic Acid Biosynthesis.

Rheum officinale Baill. is an important traditional Chinese medicinal herb, its dried roots and rhizomes being widely utilized to cure diverse diseases. However, previous studies mainly focused on the active compounds and their pharmacological effects, and the molecular mechanism underlying the biosynthesis of these ingredients in R. officinale is still elusive. Here, we performed comparative transcriptome analyses to elucidate the differentially expressed genes (DEGs) in the root, stem, and leaf of R. officinale. A total of 236,031 unigenes with N50 of 769 bp was generated, 136,329 (57.76%) of which were annotated. A total of 5884 DEGs was identified after the comparative analyses of different tissues; 175 and 126 key enzyme genes with tissue-specific expression were found in the anthraquinone, catechin/gallic acid biosynthetic pathway, respectively, and some of these key enzyme genes were verified by qRT-PCR. The phylogeny of the PKS III family in Polygonaceae indicated that probably only PL_741 PKSIII1, PL_11549 PKSIII5, and PL_101745 PKSIII6 encoded PKSIII in the polyketide pathway. These results will shed light on the molecular basis of the tissue-specific accumulation and regulation of secondary metabolites in R. officinale, and lay a foundation for the future genetic diversity, molecular assisted breeding, and germplasm resource improvement of this essential medicinal plant.

Rheum officinale Baill. Treats zebrafish embryo thrombosis by regulating NOS3 expression in the arginine biosynthesis pathway.

BACKGROUND: Rheum officinale Baill. (ROB), as one of the traditional Chinese medicines for promoting blood circulation and removing blood stasis, has a wide range of pharmacological effects, such as cardiovascular protection, and has become a common drug in the clinical care of thrombosis. OBJECTIVE: Although there are some pharmacological studies on ROB in the treatment of thrombotic diseases, the mechanism and material basis are still unclear. Based on the arginine biosynthesis signalling pathway, this research explored the target proteins and metabolites related to the intervention of ROB in thrombosis and expounded on the antithrombotic mechanism of ROB from the comprehensive perspectives of target prediction, intermediate metabolites and potential metabolic pathways. METHODS: In this research, ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) technology was used to qualitatively detect the chemical compounds of ROB, and the antithrombotic activity of ROB was evaluated by establishing a zebrafish model. The target function was predicted by network pharmacology, and differential metabolites were screened by metabolomics and multivariate statistical analysis methods. Correlation analysis of network pharmacology and metabolomics screening results was conducted to identify the potential pathway of ROB intervention in thrombosis, and the prediction results were further verified. RESULTS: ROB significantly reduced the reactive oxygen species (ROS) staining intensity in zebrafish induced by phenylhydrazine (PHZ) and improved the inhibition rate of thrombosis. By constructing the "herb-disease-component-target" network, it was concluded that the active ingredients of ROB in treating thrombosis involved emodin, aloe-emodin and physcion, and the key targets included nitric oxide synthase 2 (NOS2) and nitric oxide synthase 3 (NOS3). A total of 341 differential metabolites in zebrafish with thrombosis were screened by partial least squares discriminant analysis (PLS-DA). The results of reverse transcription-polymerase chain reaction (RT-PCR) experiments and targeted metabolomics verification showed that ROB was mainly involved in improving thrombosis by upregulating the expression of NOS3 mRNA and regulating the levels of arginine, glutamate and glutamine in the arginine biosynthesis pathway. CONCLUSIONS: ROB improved thrombosis by regulating the expression of NOS3 mRNA and the contents of arginine, glutamate and glutamine in the arginine biosynthesis signalling pathway.

Angelica dahurica and Rheum officinale Facilitated Diabetic Wound Healing by Elevating Vascular Endothelial Growth Factor.

Traditional Chinese medicine (TCM) provides alternative treatment choices for diabetic wounds. The aim of this study was to evaluate the effects of Angelica dahurica and Rheum officinale (ARE) on diabetic wounds and its underlying action mechanism. A total of 36 healthy male Sprague-Dawley rats were randomly divided into three groups: diabetes mellitus (DM) rats treated with ARE (DM-ARE), DM rats treated with 0.9% saline (DM-NS), and non-DM rats treated with 0.9% saline (NDM-NS). DM was induced by intraperitoneal administration of 40 mg/kg of streptozotocin after a 2-week high-fat diet feeding. After excisional skin wounds and treatments, the remaining wound area (RWA) in each group was measured. The RWA in the DM-NS group (69.60% ± 2.35%) was greater than that in the DM-ARE (55.70% ± 1.85%) and NDM-NS groups (52.50% ± 2.77%) on day 6. Besides, the DM-ARE group showed higher vascular endothelial growth factor (VEGF), higher inducible nitric oxide synthase (iNOs), higher [Formula: see text]-smooth muscle actin ([Formula: see text]-SMA), and lower nuclear factor kappa-light-chain-enhancer of activated B cell (NF-[Formula: see text]B) expression in the wound skin tissue. These results showed that treatment with ARE shifted the recovery pattern of diabetic rats to the pattern of nondiabetic rats, indicating that ARE may improve wound healing in diabetic conditions.

Topical therapy with rhubarb navel plasters in patients with chronic constipation: Results from a prospective randomized multicenter study.

ETHNOPHARMACOLOGICAL RELEVANCE: Constipation is a functional gastrointestinal disorder and one of the most prevalent conditions encountered in primary care settings. Rhubarb navel dressings have been used for more than 2,000 years in Chinese medicine to treat constipation. However, the effect of topical rhubarb administration has still not been well recognized and this strategy is not yet established as an evidence-based approach. AIM OF THE STUDY: In this study, we performed a prospective multicentric randomized controlled trial to evaluate the efficacy and safety of rhubarb navel plasters for patients with chronic constipation. MATERIALS AND METHODS: A total of 374 patients from six teaching hospitals were prospectively included between 09/2016 and 10/2017 in the study based on Rome III criteria. All participants were randomly assigned (1:1) into verum/placebo group and given either Rheum officinale rhubarb powder or a placebo flour stick on the navel for 6 h/day/8 days. Primary outcome measures were the Cleveland Constipation Score (CCS) for the feces condition and Bristol Stool Scale (BSS) for stool consistency and 24 h defecation frequency. RESULTS: The groups demonstrated no statistical differences in demographic data, clinical diagnoses and concomitant medication at baseline. In patients treated with the verum CCS was 5.61 (day 8, 95% CI 5.15-6.07) compared to 8.62 (95% CI 8.07-9.18) in placebo-treated controls (P < 0.001). The mean change of CCS at the end of treatment (day 8 versus [vs] day 0) was 6.04 in verum-treated vs 2.73 in placebo-treated controls (P < 0.001). Also 24 h defecation frequency (BSS) showed superior results (day 5: 0.84 vs 0.62, 95% CI 0.67-0.80, P < 0.001; day 6: 0.82 vs 0.60, 95% CI 0.64-0.78, P < 0.01 and day 8: 0.82 vs 0.60, 95% CI 0.64-0.78, P < 0.01) and better BSS type classification during treatment than controls (P < 0.05). No significant differences in adverse events between both groups became obvious. CONCLUSION: Rhubarb navel plaster administration over an 8-day-treatment period resulted in significantly improved bowel function as demonstrated by the CCS, 24 h defecating frequency and BSS. Our results suggest that rhubarb navel plasters represent a feasible, safe and efficient application route for the treatment of patients suffering from chronic constipation.

Rheum officinale extract promotes the innate immunity of orange-spotted grouper (Epinephelus coioides) and exerts strong bactericidal activity against six aquatic pathogens.

We investigated the antimicrobial properties and the effects of Rheum officinale extract (ROE) on nonspecific immune parameters of orange-spotted grouper (Epinephelus coioides) in vitro and in vivo. The in vitro analysis was conducted by treating grouper primary head kidney leukocytes with various concentrations of ROE. The phagocytic rate of the leukocytes was elevated in a dose-dependent manner from 0.01 to 0.1 mg/ml, but decreased with higher concentrations of ROE (0.5 and 1.0 mg/ml). The production of reactive oxygen species (ROS) was strongly enhanced in a dose-dependent manner by treatment with ROE doses of 0.1-10.0 mg/ml. However, morphological changes (e.g., rounding and shrinkage of cells, chromatin condensation, fragmentation, and appearance of apoptotic bodies) were observed in the leukocytes after incubation with higher concentrations of ROE (1.0 and 10.0 mg/ml). A 28-day feeding trial was performed to assess the impact of dietary administration of ROE on grouper innate immunity parameters. Fish were fed with feed supplemented with 0, 0.1, 1.0, or 5.0 g ROE per kg of feed. The phagocytic activity of the animals' leukocytes was significantly elevated in all ROE-fed groups on day 1 and in groups fed with ROE at 0.1 or 1.0 g/kg on day 14. Production of ROS was substantially increased on day 1 in fish fed with ROE at 1.0 and 5.0 g/kg, but decreased steadily later on. The ability to generate ROS increased steadily until day 7 in fish fed the lowest concentration of ROE (0.1 mg/ml), but decreased thereafter. ROE showed excellent antibacterial activity against six pathogens of aquatic animals: Vibrio parahaemolyticus, V. vulnificus, V. alginolyticus, V. carchariae, Aeromonas hydrophila, and Edwardsiella tarda. The minimum inhibitory and bactericidal concentrations of measured ROE-derived anthraquinones were 10.57-84.53 µg/ml and 10.57-169.05 µg/ml, respectively.

Organic anion transporter 1 and 3 contribute to traditional Chinese medicine-induced nephrotoxicity.

With the internationally growing popularity of traditional Chinese medicine (TCM), TCM-induced nephropathy has attracted public attention. Minimizing this toxicity is an important issue for future research. Typical nephrotoxic TCM drugs such as Aristolochic acid, Tripterygium wilfordii Hook. f, Rheum officinale Baill, and cinnabar mainly damage renal proximal tubules or cause interstitial nephritis. Transporters in renal proximal tubule are believed to be critical in the disposition of xenobiotics. In this review, we provide information on the alteration of renal transporters by nephrotoxic TCMs, which may be helpful for understanding the nephrotoxic mechanism of TCMs and reducing adverse effects. Studies have proven that when administering nephrotoxic TCMs, the expression or function of renal transporters is altered, especially organic anion transporter 1 and 3. The alteration of these transporters may enhance the accumulation of toxic drugs or the dysfunction of endogenous toxins and subsequently sensitize the kidney to injury. Transporters-related drug combination and clinical biomarkers supervision to avoid the risk of future toxicity are proposed.

Characterization of the complete chloroplast genome of medicinal plant Rheum officinale (Polygonaceae).

The complete chloroplast (cp) genome of Rheum officinale Baill. was determined based on the Illumina Sequencing data. The cp genome is 161,563 bp in length. The overall G + C content of the cp genome was 37.31%. The R. officinale cp genome contains 129 genes, including 84 protein-coding genes, eight rRNA genes (four rRNA species), and 37 tRNA genes (20 tRNA species). A neighbour-joining phylogenetic tree clarified that the cp genome of R. officinale was closely related to that of R. palmatum in Polygonaceae.

Affinity chromatographic methodologies based on immobilized voltage dependent anion channel isoform 1 and application in protein-ligand interaction analysis and bioactive compounds screening from traditional medicine.

Voltage dependent anion channel isoform 1 (VDAC-1) serves as an attractive target of anti-cancer drugs by mediating the entry and exit of metabolites between cytoplasm and mitochondria. This work reports on the preparation of a VDAC-1-based bioaffinity chromatographic stationary phase by linking the protein on lecithin modified microspheres. An assay of chromatographic methods including frontal analysis, zonal elution, injection dependent analysis and nonlinear chromatography were utilized to investigate the bindings of ATP, NADH and NADPH to VDAC-1. Electrostatic interactions were found to be main forces during these bindings. The calculated association constants of the three ligands to VDAC-1 showed good agreements between diverse chromatographic methods. Validated application of the stationary phase was performed by screening anti-cancer compounds of Rheum officinale Baill. using high performance affinity chromatography coupled with electrospray ionization-quadrupole time of flight mass spectrometry. Chrysophanol, emodin, rhein, aloe-emodin and catechin were identified as the bioactive components of the herb. These compounds targeted VDAC-1 through Thr207 and the N-terminal region of the protein. Taken together, the current stationary phase was possible to become a promising tool for protein-ligand interaction analysis and anti-cancer drug screening from complex matrices.

Clinical study on influence of Rheum officinale on serum high mobility group protein B1 in patients with severe acute pancreatitis / 重庆医学

Objective To observe the effect of rhubarb enema on serum level of high mobility group protein B1 (HMGB1) in patients with severe acute pancreatitis (SAP).Methods A total of 60 cases of patients with SAP in our hospital were collected from October 2014 to October 2016,and were randomly divided into the observation group and control group (30 cases in each group).Serum levels of HMGB1 were dynamically detected on the 1st,3rd and 5th day after admission.The acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) was conducted.The recovery time of gastrointestinal function and time for continuous renal replacement therapy (CRRT) were observed.Results On the 1st day after admission,no statistically significant difference was found in serum level of HMGB1 between the two groups (P＞0.05).The serum level of HMGB1 in the observation group was obviously decreased on the 5th day after admission,which was lower than that in the control group,there was statistically significant difference(P＜0.05).In the observation group,the value of difference between serum level of HMGB1 on the 1st day after admission and that on the 3rd day after admission was significantly negatively related with the APACHE Ⅱ score on the 3rd day after admission(r=-0.604,P＜0.05).In the observation group,the remission time of abdominal pain and abdominal distension,first time of exhaust and defecation and time for CRRT were significantly shorter than those in the control group,there were statistically significant differences (P＜0.05).Conclusion Rhubarb could improvesymptoms and prognosis of patients with SAP through effectively inhibit the expression of HMGB1.

Clinical Study onDa Huang (Rheum Officinale) Powder Application at Shenque (CV 8) for Incomplete Intestinal Obstruction / 上海针灸杂志

Objective To observe the clinical efficacy ofDa Huang (Rheum Officinale) powder application at Shenque (CV 8) in treating incomplete intestinal obstruction.Method Fifty-eight patients with incomplete intestinal obstruction were randomized into a treatment group and a control group, 29 cases in each group. The control group was by enema with laxative medicine, while the treatment group was byDa Huang (Rheum Officinale) application at Shenque (CV 8) in addition to enema. The time of gassing and defecation, and abdominal bloating intensity were observed.Result The time of gassing and defecation and abdominal bloating intensity in the treatment group were significantly different from that in the control group (P<0.05).ConclusionDa Huang (Rheum Officinale) application at Shenque (CV 8) is an effective approach in treating incomplete intestinal obstruction.

Clinical effect of Rhubarb retention enema combined with routine western medicine on acute pancreatitis / 国际中医中药杂志

Objective To detect the effect of Rhubarb retention enema on patients with acute pancreatitis(AP).MethodsA total of 84 AP patients were enrolled in this study. Patients were divided into the control group(n=42) and Rhubarb enema observation group(n=42). Control group was treated with fasting, continuous gastrointestinal decompression, correcting water electrolyte and acid-base imbalance, with the oral administration of octreotide and gabexatemesilate to inhibit pancreatic secretion and enzyme activity. On the basis of the control group, the observation group was treated with rhubarb retention enema. IL-17, IL-10, and IL-6 expression was detected by ELISA analysis. The clinical effect was compared.Results The clinical effect rate (85.7%vs.71.4%,χ2=2.366,P=0.043) in observation group was significantly higher than that in control group. After treatment of 7 days, IL-17 (13.53 ± 3.16 ng/mlvs. 20.63 ± 4.83 ng/ml,t=2.416) and IL-6 (22.82 ± 4.56 ng/mlvs. 31.59 ± 6.63 ng/ml,t=2.421) expression was significantly lower and IL-10 (16.32 ± 4.15 ng/mlvs. 12.17 ± 3.22 ng/ml,t=2.326) expression was significantly higher in observation group than those in control group(P<0.05). The reduction of blood amylase (125.69 ± 32.47 U/Lvs. 259.26 ± 51.44 U/L,t=7.451) and urine amylase (204.73 ± 43.83 U/Lvs. 334.25 ± 60.18 U/L,t=7.323) in the observation group was significantly higher than those in the control group(P<0.01). Abdominal pain and abdominal distension recovery time (4.24 ±1.06 dvs. 3.02 ± 0.62 d,t=2.521), exhaust gas and defecation recovery time (5.42 ± 1.25 dvs. 3.26 ± 0.73 d,t=5.124), temperature recovery time (5.63 ± 1.46 dvs. 4.58 ± 0.92 d,t=2.418), and hospitalization time (18.65 ± 4.16 dvs. 13.78 ± 3.15 d,t=2.386) were higher in control group than those in observation group (P<0.05 orP<0.01). Conclusion Rhubarb enema can regulate the IL-17/ IL-10, and inhibit the inflammatory reaction.

Efficacy of mirabilite and rheum officinale combined with pulse high-volume hemofiltration for treatment of patients with severe acute pancreatitis / 中国中西医结合急救杂志

Objective To observe the clinical efficacy of mirabilite and rheum officinale combined with pulse high-volume hemofiltration(PHVHF)in treatment of patients with severe acute pancreatitis(SAP). Methods A total of 11 patients with SAP in Department of Critical Care Medicine of Qiannan Traditional Chinese Medicine Hospital of Guizhou Province received the combined treatment of external application of mirabilite,gavage of rheum officinale decoction and PHVHF. The changes in abdominal symptoms,vital signs,blood gas analysis,blood biochemical indicators,and the acute physiology and chronic health evaluation(APACHEⅡ)score,Ranson score and prognosis were observed and compared before and after treatment. Results After treatment,the patients' fever〔body temperature(℃):37.31±0.13 vs. 39.12±0.12〕,tachycardia〔heart rate(beats/min):106±17 vs. 123±22〕, respiratory distress〔respiratory frequency(times/min):23±6 vs. 31±5〕and other symptoms were ameliorated in different degrees,and the APACHE Ⅱ score(9.1±2.2 vs. 21.2±8.2),Ranson score(3.2±1.1 vs. 5.8±1.3)were decreased significantly ,all the above indexes compared before and after treatment being of statistical significant differences(all P<0.05). The indexes of hemodynamics of 10 survival patients were stable,heart rate(beats/min:106±17 vs. 123±22)was decreased,and mean arterial pressure〔MAP,mmHg(1 mmHg=0.133 kPa):73±6 vs. 41±5〕was increased gradually(both P<0.05). After treatment,serum amylase〔AMY(U/L):367.3±102.3 vs. 923.5±351.7〕,alanine aminotransferase〔ALT(U/L):63.3±23.2 vs. 201.5±123.2〕,total bilirubin〔TBil (μmol/L):22.1±20.1 vs. 56.1±63.2〕,serum creatinine〔SCr(μmol/L):132.1±23.5 vs. 392.4±12.2〕,urea nitrogen〔BUN(mmol/L):9.5±4.9 vs. 19.2±5.9〕, K+(mmol/L:4.2±0.2 vs. 5.6±2.1) were significantly decreased,arterial partial pressure of carbon dioxide〔(PaCO2,mmHg):35.1±7.1 vs. 27.2±5.5〕,arterial partial pressure of oxygen〔PaO2(mmHg):93.2±13.2 vs. 49.1±7.2〕and oxygenation index(mmHg:187.1±28.5 vs. 148.2±32.7),Na+(mmol/L:132.1±19.1 vs. 127.1±42.1)were significantly increased compared with those before treatment, there were statistically significant differences(P<0.05 or P<0.01). Conclusion The combined treatment of mirabilite,rheum officinale and PHVHF has significant effects on the treatment of patients with SAP,and it can be one of the assistant therapies of SAP.

Genetic diversity of the endemic and medicinally important plant Rheum officinale as revealed by Inter-Simpe Sequence Repeat (ISSR) Markers.

Rheum officinale Baill., an important but endangered medicinal herb, is endemic to China. Inter-simple sequence repeat (ISSR) markers were employed to investigate the genetic diversity and differentiation of 12 populations of R. officinale. Thirteen selected primers yielded 189 bright and discernible bands, with an average of 14.54 per primer. The genetic diversity was low at the population level, but pretty high at the species level (H = 0.1008, I = 0.1505, PPB = 28.95% vs. H = 0.3341, I = 0.5000, PPB = 95.24%, respectively) by POPGENE analysis. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly among populations (74.38%), in line with the limited gene flow (N(m) = 0.2766) among populations. Mantel test revealed a significant correlation between genetic and geographic distances (r = 0.5381, P = 0.002), indicating the role of geographic isolation in shaping the present population genetic structure. Both Bayesian analysis and UPGMA cluster analysis demonstrated the similar results. Our results imply that the conservation efforts should aim to preserve all the extant populations of this endangered species, and cultivation is proposed in this study.