Comparative pharmacokinetics of five rhubarb anthraquinones in normal and thrombotic focal cerebral ischemia-induced rats

Comparative Pharmacokinetic Study of Rhubarb Anthraquinones in Normal and Nonalcoholic Fatty Liver Disease Rats

BACKGROUND AND OBJECTIVES

Rhubarb anthraquinones contain five main components, that is, rhein, emodin, aloe-emodin, chrysophanol, and physcion, which demonstrate good therapeutic effects on nonalcoholic fatty liver disease (NAFLD). However, research on its pharmacokinetics in NAFLD remains lacking. This study aimed to investigate the pharmacokinetic differences of rhubarb anthraquinones in normal and NAFLD rats.

METHODS

This study developed an NAFLD rat model by high-fat diet feeding for 6 weeks. Normal and NAFLD groups were orally administered different rhubarb anthraquinones doses (37.5, 75, and 150 mg/kg). The concentration of the rhein, emodin, aloe-emodin, chrysophanol, and physcion in plasma was determined by high-performance liquid chromatography-ultraviolet.

RESULTS

The results revealed significant differences in pharmacokinetic behavior between normal and NAFLD rats. Compared with normal rats, NAFLD rats demonstrated significantly increased maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0 → ∞) of rhubarb anthraquinones (P < 0.05), as well as significantly prolonged time to reach maximum plasma concentration (Tmax), terminal elimination half-life (t1/2), and mean residence time (MRT) of rhubarb anthraquinones (P < 0.05).

CONCLUSIONS

This study indicates significant differences in the pharmacokinetics of rhubarb anthraquinones between the physiological and NAFLD states of rats. Rhubarb anthraquinone demonstrated a longer retention time and slower absorption rate in NAFLD rats and exhibited higher bioavailability and peak concentration. This finding provides important information for guiding the clinical use of rhubarb anthraquinones under pathological conditions.

Clinical effect of rhubarb on the treatment of chronic renal failure: A meta-analysis

Objective: 1) To evaluate the effificacy of rhubarb in the treatment of chronic renal failure (CRF); 2) To explore the safety for rhubarb-based therapy on chronic renal failure. Methods: The randomized and semi randomized controlled trials of Rhubarb in the treatment of chronic renal failure in medical electronic databases (up to September 2021) were searched, and meta-analysis was carried out by revman 5.3 software. Results: A total of 2,786 patients were included in 34 literatures, including 1,474 cases in the treatment group and 1,312 cases in the control group. The results of meta-analysis showed that Serum creatinine (SCR) [MD = 123.57, 95% Cl (111.59, 131.96)], Blood urea nitrogen (BUN) [MD = -3.26, 95% Cl (-4.22,-2.31)], Creatinine clearance rate (CCR) [MD = 3.95, 95% Cl (-0.03, 7.93)], Hemoglobin (Hb) [MD = 7.70, 95% Cl (-0.18, 15.58)] and Uric acid (UA) [MD = -42.79, 95% CI (-66.29, -19.29)]. The total effective rate of improving symptoms and signs in chronic renal failure patients [Peto or = 4.14, 95% Cl (3.32, 5.16)]. Conclusion: This systematic review and meta-analysis demonstrated that rhubarb has a positive therapeutic effect, which may provide confifidence and some theoretical reference for clinical application to a certain extent. Compared with the control group, rhubarb alone or traditional Chinese medicine compound containing Rhubarb can significantly reduce Serum creatinine, Blood urea nitrogen and Uric acid, increase Creatinine clearance rate, and improve the total effective rate of symptoms and signs. However, there is no evidence that rhubarb is more effective than the control group in increasing hemoglobin. In addition, due to the low quality of research methodology in the included literature, it is necessary to further study high-quality literature to evaluate its efficacy and safety. Systematic Review Registration: https://inplasy.com/inplasy-2021-10-0052/, identifier INPLASY2021100052.

Research Progress on the Positive and Negative Regulatory Effects of Rhein on the Kidney: A Review of Its Molecular Targets

Currently, both acute kidney injury (AKI) and chronic kidney disease (CKD) are considered to be the leading public health problems with gradually increasing incidence rates around the world. Rhein is a monomeric component of anthraquinone isolated from rhubarb, a traditional Chinese medicine. It has anti-inflammation, anti-oxidation, anti-apoptosis, anti-bacterial and other pharmacological activities, as well as a renal protective effects. Rhein exerts its nephroprotective effects mainly through decreasing hypoglycemic and hypolipidemic, playing anti-inflammatory, antioxidant and anti-fibrotic effects and regulating drug-transporters. However, the latest studies show that rhein also has potential kidney toxicity in case of large dosages and long use times. The present review highlights rhein's molecular targets and its different effects on the kidney based on the available literature and clarifies that rhein regulates the function of the kidney in a positive and negative way. It will be helpful to conduct further studies on how to make full use of rhein in the kidney and to avoid kidney damage so as to make it an effective kidney protection drug.

The influence of essential oils from ZhaLi NuSi Prescription on the pharmacokinetics of its non-volatile components in normal rats

Hui Medicine ZhaLi NuSi Prescription (ZLNS) is described in "Hui Hui Prescription," and it has been used to treat cerebral infarction in Hui Region, China. In this study, a rapid and reliable ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS/MS) method was established and applied to simultaneously determine geniposidic acid, oxypaeoniflorin, hydroxysafflor yellow A, caffeic acid, magnoflorine, paeoniflorin, ferulic acid, β-ecdysterone, icariin, rhein, and baohuoside I in rat plasma. The pharmacokinetic parameters of these components and the influence of essential oils (EOs) on them were investigated in normal rats. The results showed that the pharmacokinetic parameters (AUC_0 - t , AUC_0 - ∞ , t_1/2 , t_max , c_max ) of the aforementioned compounds were significantly changed after co-administering with ZLNS EO. The AUC values of oxypaeoniflorin, paeoniflorin, ferulic acid, and baohuoside I with EOs were decreased significantly. This is the first report for the comparative pharmacokinetic study of ZLNS bioactive components in normal rats, which may provide the basis for drug interaction study in vivo and insight into their clinical applications.

Pharmacokinetics of Anthraquinones from Medicinal Plants

Anthraquinones are bioactive natural products, some of which are active components in medicinal medicines, especially Chinese medicines. These compounds exert actions including purgation, anti-inflammation, immunoregulation, antihyperlipidemia, and anticancer effects. This study aimed to review the pharmacokinetics (PKs) of anthraquinones, which are importantly associated with their pharmacological and toxicological effects. Anthraquinones are absorbed mainly in intestines. The absorption rates of free anthraquinones are faster than those of their conjugated glycosides because of the higher liposolubility. A fluctuation in blood concentration and two absorption peaks of anthraquinones may result from the hepato-intestinal circulation, reabsorption, and transformation. Anthraquinones are widely distributed throughout the body, mainly in blood-flow rich organs and tissues, such as blood, intestines, stomach, liver, lung, kidney, and fat. The metabolic pathways of anthraquinones are hydrolysis, glycuronidation, sulfation, methylation/demethylation, hydroxylation/dehydroxylation, oxidation/reduction (hydrogenation), acetylation and esterification by intestinal flora and liver metabolic enzymes, among which hydrolysis, glycuronidation and sulfation are dominant. Of note, anthraquinones can be transformed into each other. The main excretion routes for anthraquinones are the kidney, recta, and gallbladder. Conclusion: Some anthraquinones and their glycosides, such as aloe-emodin, chrysophanol, emodin, physcion, rhein and sennosides, have attracted the most PK research interest due to their more biological activities and/or detectability. Anthraquinones are mainly absorbed in the intestines and are mostly distributed in blood flow-rich tissues and organs. Transformation into another anthraquinone may increase the blood concentration of the latter, leading to an increased pharmacological and/or toxicological effect. Drug-drug interactions influencing PK may provide insights into drug compatibility theory to enhance or reduce pharmacological/toxicological effects in Chinese medicine formulae and deserve deep investigation.

Physcion Protects Rats Against Cerebral Ischemia-Reperfusion Injury via Inhibition of TLR4/NF-kB Signaling Pathway

Background

Ischemic stroke (IS) is characterized by the rapid loss of brain function due to ischemia. Physcion has been found to have a neuroprotective effect against cerebral ischemia-reperfusion (I/R) injury. However, the mechanism by which physcion regulates cerebral I/R injury remains largely unknown.

Methods

An oxygen-glucose deprivation/reperfusion (OGD/R) model in SH-SY5Y cells and a rat cerebral ischemia-reperfusion (I/R) model were established, respectively. CCK-8 and flow cytometry assays were used to detect the viability and apoptosis of SH-SY5Y cells. Moreover, enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of SOD, MDA, GSH-Px, TNF-α, IL-1β, IL-6 and IL-10 in the supernatant of SH-SY5Y cells. Meanwhile, Western blot assay was used to detect the expressions of TLR4, p-p65 and p-IκB in SH-SY5Y cells and I/R rats.

Results

In this study, physcion treatment significantly rescued OGD/R-induced neuronal injury. In addition, physcion decreased inflammatory response in SH-SY5Y cells after OGD/R insult, as shown by the decreased levels of the pro-inflammatory factors TNF-α, IL-1β, IL-6 and IL-10. Moreover, physcion attenuated the oxidative stress in OGD/R-treated SY-SY5Y cells, as evidenced by the increased SOD and GSH levels and the decreased ROS and MDA levels. Meanwhile, physcion significantly reduced cerebral infarction, attenuated neuronal injury and apoptosis in I/R rats. Furthermore, physcion markedly decreased the expressions of TLR4, p-NF-κB p65 and p-IκB in the brain tissues of rats subjected to I/R and in SH-SY5Y cells exposed to OGD/R.

Conclusion

In conclusion, our study indicated that physcion protected neuron cells against I/R injury in vitro and in vivo by inhibition of the TLR4/NF-kB pathway; thus, physcion might serve as a promising therapeutic candidate for IS.

Mechanism of Radix Rhei Et Rhizome Intervention in Cerebral Infarction: A Research Based on Chemoinformatics and Systematic Pharmacology

OBJECTIVE

To explore the therapeutic targets, network modules, and coexpressed genes of Radix Rhei Et Rhizome intervention in cerebral infarction (CI), and to predict significant biological processes and pathways through network pharmacology. To explore the differential proteins of Radix Rhei Et Rhizome intervention in CI, conduct bioinformatics verification, and initially explain the possible therapeutic mechanism of Radix Rhei Et Rhizome intervention in CI through proteomics.

METHODS

The TCM database was used to predict the potential compounds of Radix Rhei Et Rhizome, and the PharmMapper was used to predict its potential targets. GeneCards and OMIM were used to search for CI-related genes. Cytoscape was used to construct a protein-protein interaction (PPI) network and to screen out core genes and detection network modules. Then, DAVID and Metascape were used for enrichment analysis. After that, in-depth analysis of the proteomics data was carried out to further explore the mechanism of Radix Rhei Et Rhizome intervention in CI.

RESULTS

(1) A total of 14 Radix Rhei Et Rhizome potential components and 425 potential targets were obtained. The core components include sennoside A, palmidin A, emodin, toralactone, and so on. The potential targets were combined with 297 CI genes to construct a PPI network. The targets shared by Radix Rhei Et Rhizome and CI include ALB, AKT1, MMP9, IGF1, CASP3, etc. The biological processes that Radix Rhei Et Rhizome may treat CI include platelet degranulation, cell migration, fibrinolysis, platelet activation, hypoxia, angiogenesis, endothelial cell apoptosis, coagulation, and neuronal apoptosis. The signaling pathways include Ras, PI3K-Akt, TNF, FoxO, HIF-1, and Rap1 signaling pathways. (2) Proteomics shows that the top 20 proteins in the differential protein PPI network were Syp, Syn1, Mbp, Gap43, Aif1, Camk2a, Syt1, Calm1, Calb1, Nsf, Nefl, Hspa5, Nefh, Ncam1, Dcx, Unc13a, Mapk1, Syt2, Dnm1, and Cltc. Differential protein enrichment results show that these proteins may be related to synaptic vesicle cycle, vesicle-mediated transport in synapse, presynaptic endocytosis, synaptic vesicle endocytosis, axon guidance, calcium signaling pathway, and so on.

CONCLUSION

This study combined network pharmacology and proteomics to explore the main material basis of Radix Rhei Et Rhizome for the treatment of CI such as sennoside A, palmidin A, emodin, and toralactone. The mechanism may be related to the regulation of biological processes (such as synaptic vesicle cycle, vesicle-mediated transport in synapse, presynaptic endocytosis, and synaptic vesicle endocytosis) and signaling pathways (such as Ras, PI3K-Akt, TNF, FoxO, HIF-1, Rap1, and axon guidance).

Pharmacodynamics of Five Anthraquinones (Aloe-emodin, Emodin, Rhein, Chysophanol, and Physcion) and Reciprocal Pharmacokinetic Interaction in Rats with Cerebral Ischemia

(1) Background: Rhubarb anthraquinones—a class of components with neuroprotective function—can be used to alleviate cerebral ischemia reperfusion injury. (2) Methods: The three pharmacodynamic indicators are neurological function score, brain water content, and cerebral infarction area; UPLC-MS/MS was used in pharmacokinetic studies to detect plasma concentrations at different time points, and DAS software was used to calculate pharmacokinetic parameters in a noncompartmental model. (3) Results: The results showed that the pharmacodynamics and pharmacokinetics of one of the five anthraquinone aglycones could be modified by the other four anthraquinones, and the degree of interaction between different anthraquinones was different. The chrysophanol group showed the greatest reduction in pharmacodynamic indicators comparing with other four groups where the rats were administered one of the five anthraquinones, and there was no significant difference between the nimodipine group. While the Aloe-emodin + Physcion group showed the most obvious anti-ischemic effect among the groups where the subjects were administered two of the five anthraquinones simultaneously. Emodin, rhein, chrysophanol, and physcion all increase plasma exposure levels of aloe-emodin, while aloe-emodin lower their plasma exposure levels. (4) Conclusions: This experiment provides a certain preclinical basis for the study of anthraquinone aglycones against cerebral ischemia and a theoretical basis for the study of the mechanism of interaction between anthraquinones.

Neuroprotective Effects of Anthraquinones from Rhubarb in Central Nervous System Diseases

Rhubarb is a well-known traditional Chinese medicine; it has been used in China for thousands of years. Rhubarb anthraquinones are the major medicinal ingredients derived from rhubarb including emodin, aloe-emodin, chrysophanol, rhein, physcion, and danthron. These different anthraquinone derivatives alone or in combination play a therapeutic role in central nervous system diseases (CNSD), such as cerebral ischemic stroke, intracerebral hemorrhage, traumatic brain injury, brain tumor, Alzheimer's disease, depression, and others. We review the experimental studies on these six anthraquinones in the treatment of CNSD by consulting literature published in the last 20 years in PubMed and then give a future perspective on it. In the end of this paper some deficiencies related to these studies also have been pointed out.

iTRAQ-Based Proteomics Analysis Reveals the Effect of Rhubarb in Rats with Ischemic Stroke

Background. Rhubarb, a traditional Chinese medicine, promotes viscera and remove blood stasis. Rhubarb is skilled in smoothening meridians, improving blood circulation which exhibits better efficacy on cerebral ischemic stroke. In this study, we aimed to analyze the underlying mechanisms of rhubarb which treated rats of middle cerebral artery occlusion (MCAO) model according to an iTRAQ-based proteomics and bioinformatics analysis. 30 rats were randomly allocated into three groups including sham group (SG), model group (MG), and rhubarb group (RG). Rhubarb group was given a gavage of rhubarb decoction at dose of 3 g/kg and the remaining groups were prepared with normal saline by gavage. Rats from MG and RG were induced into MCAO model. The effects of rhubarb were estimated by Modified Neurological Severity Score (mNSS) and cerebral infarct volume. The brain tissues were measured via the quantitative proteomic approach of iTRAQ coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, the bioinformatics analysis of overlapping differentially expression proteins (DEPs) was conducted by DAVID, KEGG, and Cytoscape. Specific selective DEPs were validated by Western blotting. Rats treated with rhubarb after MCAO showed a significant reduction on mNSS and cerebral infarct volume compared with MG. In MG versus SG and RG versus MG, we identified a total of 4578 proteins, of which 287 were DEPs. There were 76 overlapping DEPs between MG versus SG and RG versus MG. Through bioinformatics analysis, 14 associated pathways were searched including cGMP-PKG signaling pathway, tuberculosis, synaptic vesicle cycle, amyotrophic lateral sclerosis, long-term potentiation, and so on. 76 overlapping DEPs mainly involved synaptic vesicle cycling biological processes based on GO annotation. Further, the selective overlapping DEPs were verified at the protein level by using Western blotting. Our present study reveals that rhubarb highlights promising neuroprotective effect. Rhubarb exerts novel therapeutic action via modulating multiple proteins, targets, and pathways.

SPE-UHPLC-FLD Method for the Simultaneous Determination of Five Anthraquinones in Human Urine Using Mixed-Mode Bis(tetraoxacalix[2]arene[2]triazine) Modified Silica as Sorbent

The five anthraquinones compounds (including aloe-emodin, emodin, physcion, chrysophanol, and rhein) are regarded as the main effective ingredients in rhubarb (Dahuang in Chinese, one of the commonly used Chinese herbal medicines). In this work, a simple and effective solid phase extraction (SPE) method based on bis(tetraoxacalix[2]arene[2]triazine) modified silica gel as adsorbent was developed. Coupled with UHPLC-FLD, the developed method was successfully applied for the measuring of main anthraquinones in human urine after oral administration of the extracts of rhubarb. To obtain the highest recoveries of the five anthraquinones in the SPE process, the main parameters which may affect extraction efficiency were optimized. The optimized sorbent amount, sample loading pH, sample loading rate, washing solution, and eluent condition were obtained. The developed method showed good linearity in 0.012-1.800 μg mL-1 for the five anthraquinones with correlation coefficients more than 0.9993. The investigated LOD values ranged from 3.9 to 5.7 ng mL-1, while the LOQs were between 12.0 and 18.2 ng mL-1. The recoveries of the method were also investigated, which were in the range of 94.8-106.6%. The application of the mixed-mode SPE materials in the proposed method was feasible and simple, and suitable for the enrichment of anthraquinones in urine samples.

Discovery of Radioiodinated Monomeric Anthraquinones as a Novel Class of Necrosis Avid Agents for Early Imaging of Necrotic Myocardium

Assessment of myocardial viability is deemed necessary to aid in clinical decision making whether to recommend revascularization therapy for patients with myocardial infarction (MI). Dianthraquinones such as hypericin (Hyp) selectively accumulate in necrotic myocardium, but were unsuitable for early imaging after administration to assess myocardial viability. Since dianthraquinones can be composed by coupling two molecules of monomeric anthraquinone and the active center can be found by splitting chemical structure, we propose that monomeric anthraquinones may be effective functional groups for necrosis targetability. In this study, eight radioiodinated monomeric anthraquinones were evaluated as novel necrosis avid agents (NAAs) for imaging of necrotic myocardium. All (131)I-anthraquinones showed high affinity to necrotic tissues and (131)I-rhein emerged as the most promising compound. Infarcts were visualized on SPECT/CT images at 6 h after injection of (131)I-rhein, which was earlier than that with (131)I-Hyp. Moreover, (131)I-rhein showed satisfactory heart-to-blood, heart-to-liver and heart-to-lung ratios for obtaining images of good diagnostic quality. (131)I-rhein was a more promising "hot spot imaging" tracer for earlier visualization of necrotic myocardium than (131)I-Hyp, which supported further development of radiopharmaceuticals based on rhein for SPECT/CT ((123)I and (99m)Tc) or PET/CT imaging ((18)F and (124)I) of myocardial necrosis.

The synergism mechanism of Rhubarb Anthraquinones on constipation elucidated by comparative pharmacokinetics of Rhubarb extract between normal and diseased rats

In the study, it was hypothesized that Rhubarb Anthraquinones synergistically enhanced the purgative effect on constipation rat from the direct and indirect pathway at the same time. A validated HPLC method was successfully applied to elucidate the synergism mechanism from pharmacokinetics aspect after oral administration of Rhubarb extract with a dose of 0.25 g to normal and constipation rats. Comparison of the pharmacokinetic data of normal and constipation rats showed that there were significant differences (p < 0.05) in the main pharmacokinetic parameters. The C max and AUC of emodin in constipation rats were about ten times that of normal rats, while the t 1/2 was remarkably decreased (p < 0.05). However, a significant decrease (p < 0.05) in AUC value for aloe-emodin and rhein was observed in model group compared with normal group. The results may be attributed to the direct action of aloe-emodin and rhein on intestinal cell membranes and the indirect action of emodin on bowel movement through the adjustment by nervous system.

Chrysophanol inhibits NALP3 inflammasome activation and ameliorates cerebral ischemia/reperfusion in mice

The most effective way to contain cerebral ischemic injury is reperfusion; however, reperfusion itself may result in tissue injury, for which inflammatory damage is one of the main causative factors. NALP3 inflammasome is a multiprotein complex. It consists of NALP3, ASC, and caspase-1, whose function is to switch on the inflammatory process. Chrysophanol is an extract from plants of Rheum genus and it possesses many pharmacological effects including its anti-inflammation activity. In this study, the effects of chrysophanol in cerebral ischemia/reperfusion and the potential mechanisms were investigated. Male CD1 mice were subject to transient middle cerebral artery occlusion (tMCAO). The NALP3 inflammasome activation status and its dynamic expression during the natural inflammatory response induced by tMCAO were first profiled. The neuroprotective effects of chrysophanol were then assessed and the potential mechanisms mediating the observed neuroprotection were then explored. Physical parameters including neurological deficit, infarct size, brain edema, and BBB permeability were measured at 24 h after tMCAO. Confocal microscopy, Western blotting, immunohistochemistry, and qRT-PCR techniques were utilized to analyze the expression of NALP3 inflammasome and IL-1β. Our results indicated that the brain tissue damage during cerebral ischemia/reperfusion is accompanied by NALP3 inflammasome activation. Chrysophanol could inhibit the activation of NALP3 inflammasome and protect cerebral ischemic stroke.