Antiprotozoal potential of Vismia species (Hypericaceae), medicinal plants used to fight cutaneous leishmaniasis.

ETHNOPHARMACOLOGICAL RELEVANCE: Species of Vismia (Hypericaceae), known in Brazil as "lacre", are commonly used in traditional Amazonian medicine for the treatment of skin lesions, including those caused by Leishmania infection. AIM OF THE STUDY: Hexane extracts from the leaves of Vismia cayennensis, V. gracilis, V. sandwithii and V. guianensis, as well as from the fruits of the latter, in addition to the anthraquinones vismiaquinone, physcion and chrysophanol isolated from these species were explored for their anti-promastigote and anti-amastigote activity on Leishmania amazonensis. MATERIALS AND METHODS: Extracts were prepared by static maceration with n-hexane. The compounds, isolated by chromatographic techniques, were identified by spectroscopic methods (1H and 13C NMR). Promastigotes of L.amazonensis were incubated with hexane extracts (1-50 µg/mL) or anthraquinones (1-50 µM) and the parasite survival analyzed. The action of compounds on reactive oxygen species (ROS) production, mitochondrial membrane potential, and membrane integrity of promastigotes were evaluated by flow cytometer, and the cytotoxicity on mammalian cells using MTT assay. Furthermore, the activity of compounds against amastigotes and nitric oxide production were also investigated. RESULTS: Vismiaquinone and physcion were obtained from the leaves of V. guianensis. Physcion, as well as chrysophanol, were isolated from V. sandwithii. Vismia cayennensis and V. gracilis also showed vismiaquinone, compound detected in lower quantity in the fruits of V. guianensis. All extracts were active against the parasite, corroborating the popular use. The greatest activity against promastigotes was achieved with V. guianensis extract (IC50 4.3 µg/mL), precisely the most used Vismia species for treating cutaneous leishmaniasis. Vismiaquinone and physcion exhibited relevant activity with IC50 12.6 and 2.6 µM, respectively. Moreover, all extracts and anthraquinones tested induced ROS production, mitochondrial dysfunction, membrane disruption and were able to kill intracellular amastigote forms, being worthy of further in vivo studies as potential antileishmanial drugs. CONCLUSIONS: The overall data achieved in the current investigation scientifically validate the traditional use of Vismia species, mainly V. guianensis, as an anti-Leishmania agent. Furthermore, the promising results presented here indicate species of Vismia as potentially useful resources of Brazilian flora for the discovery of therapeutic solutions for neglected diseases.

In silico and in vivo study of anti-inflammatory activity of Morinda longissima (Rubiaceae) extract and phytochemicals for treatment of inflammation-mediated diseases.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditionally, the plant Morinda longissima Y.Z.Ruan (Rubiaceae) is used by ethnic people in Vietnam for the treatment of liver diseases and hepatitis. AIM OF THE STUDY: The study was designed to assess the efficacy of the 95% ethanolic extract of Morinda longissima roots (MLE) in experimental immune inflammation. The phytochemical variation of root extract and the chemical structures of natural compounds were also investigated using HPLC-DAD-HR-MS analysis. MATERIALS AND METHODS: Three different doses (100, 200, and 300 mg/kg b.w.) of MLE were chosen to determine anti-inflammatory activity. The mice were given orally extracts and monitored their behavior and mortality for 14 days to evaluate acute toxicity. The volume of the paw and the histopathological evaluation were carried out. The polyphenolic phytoconstituents of MLE extract were identified using LC/MS analysis. The anti-inflammatory efficacy in silico and molecular docking simulations of these natural products were evaluated based on their cyclooxygenase (COX)-1 and 2 inhibitory effects. RESULTS: This investigation showed the 95% ethanolic extract of Morinda longissima roots was found non-toxic up to 2000 mg/kg dose level in an acute study, neither showed mortality nor treatment-related signs of toxicity in mice. Eight anthraquinones and anthraquinone glycosides of Morinda longissima roots were identified by HPLC-DAD-HR-MS analysis. In the in vivo experiments, MLE was found to possess powerful anti-inflammatory activities in comparison with diclofenac sodium. The highest anti-inflammatory activity of MLE in mice was observed at a dose of 300 mg/kg body weight. The in silico analysis showed that seven out the eight anthraquinones and anthraquinone glycosides possess a selectivity index RCOX-2/COX-1 lower than 1, indicating that these compounds are selective against the COX-2 enzyme in the following the order: rubiadin-3-methyl ether < morindone morindone-6-methyl ether < morindone-5-methyl ether < damnacanthol < rubiadin < damnacanthol-3-O-ß-primeveroside. The natural compounds with the best selectivity against the COX-2 enzyme are quercetin (9), rubiadin-3-methyl ether (7), and morindone (4), with RCOX2/COX1 ratios of 0.02, 0.03, and 0.19, respectively. When combined with the COX-2 protein in the MD research, quercetin and rubiadin-3-methyl ether greatly stabilized the backbone proteins and ligands. CONCLUSION: In conclusion, the anthraquinones and ethanolic extract of Morinda longissima roots may help fight COX-2 inflammation. To develop novel treatments for inflammatory disorders linked to this one, these chemicals should be investigated more in the future.

Neuroprotective effect of chrysophanol in Alzheimer disease via modulating the Ca2+/EGFR-PLCγ pathway.

Chrysophanol (CHR) is an anthraquinone compound found in rhubarb, and it possesses neuroprotective properties. The purpose of this study was to gain a better understanding of its role in Alzheimer's disease (AD). In vivo study, D-galactose combined with intracerebral injection of ß-protein 25-35(Aß25-35) were used to establish AD model rats. In vitro study, Aß25-35 was used to induce AD model cells. Our results indicated that CHR improves learning and memory in AD model rats and provides protection against neuronal damage in both AD model rats and cells. Additionally, we observed that CHR suppressed the protein expression of p-tau, EGFR, PLCγ, IP3R, and CAM, as well as the mRNA levels of tau, EGFR, PLCγ, IP3R, and CAM. Furthermore, we have confirmed that CHR inhibited the fluorescence expression of calcium ions (Ca2+). In conclusion, the CHR may exert neuroprotective effects in AD by reducing tau phosphorylation through the Ca2+/EGFR-PLCγ pathway.

Photocleavable Visible Light-Triggered Anthraquinone-Derived Water-Soluble Block Copolymer for Peroxynitrite Generation in Cancer Therapy.

We report a facile stimuli-responsive strategy to generate reactive oxygen and nitrogen species (ROS and RNS) in the biological milieu from a photocleavable water-soluble block copolymer under visible light irradiation (427 nm, 2.25 mW/cm2). An anthraquinone-based water-soluble polymeric nitric oxide (NO) donor (BCPx-NO) is synthesized, which exhibits NO release in the range of 40-65 µM within 10 h of photoirradiation with a half-life of 30-103 min. Additionally, BCPx-NO produces peroxynitrite (ONOO-) and singlet oxygen (1O2) under photoirradiation. To understand the mechanism of NO release and photolysis of the functional group under blue light, we prepared a small-molecule anthraquinone-based N-nitrosamine (NOD). The cellular investigation of the effect of spatiotemporally controlled ONOO- and 1O2 generation from the NO donor polymeric nanoparticles in a triple negative breast adenocarcinoma (MDA-MB-231) under visible light irradiation (white light, 5.83 mW/cm2; total dose 31.5 J/cm2) showed an IC50 of 0.6 mg/mL. The stimuli-responsive strategy using a photolabile water-soluble block copolymer employed to generate ROS and RNS in a biological setting widens the horizon for their potential in cancer therapy.

Identification of Erzhu Jiedu Recipe and its molecular mechanism underlying inhibited human hepatoma cells by UHPLC-Q-Exactive Orbitrap HRMS and network pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Erzhu Jiedu Recipe (EZJDR) is a formula of traditional Chinese medicine (TCM) for treating hepatitis B virus-related hepatocellular carcinoma (HBV-HCC). However, its effective components and the mechanism of action remain unclear. AIM OF THE STUDY: To explain how the active compounds of EZJDR suppress the growth of hepatoma cells. METHODS: UHPLC-Q-Exactive Orbitrap HRMS was used to identify the chemical constituents of EZJDR and their distribution in the serum and liver of mice. Together with experimental investigations, network pharmacology unraveled the molecular mechanism of components of EZJDR underlying the inhibited Hep3B cells. RESULTS: A total of 138 compounds which can be divided into 18 kinds of components (such as sesquiterpenoids, diterpenoids, anthraquinones, flavonoids and so on) were found in the aqueous extract of EZJDR. Of these components, the tricyclic-diterpenoids exhibited a highest exposure in the serum (74.5%) and liver (94.7%) of mice. The network pharmacology revealed that multiple components of EZJDR interacted with key node genes involved in apoptosis, proliferation, migration and metabolism through various signaling pathways, including ligand binding and protein phosphorylation. In vitro experiments demonstrated that 6 tricyclic-diterpenoids, 2 anthraquinones and 1 flavonoid inhibited the viability of Hep3B cells, with IC50 values ranging from 3.81 µM to 37.72 µM. Dihydrotanshinone I had the most potent bioactivity, arresting the S phase of cell cycle and inducing apoptosis. This compound changed the expression of proteins, including Bad, Bax, Bcl-2, Bal-x, caspase3 and catalase, which were associated with mitochondria-mediated apoptotic pathways. Moreover, dihydrotanshinone I increased the levels of p21 proteins, but decreased the phosphorylated p53, suggesting accumulation of p53 protein prevented cell cycle progression of Hep3B cells with damaged DNA. CONCLUSIONS: These results suggested that multiple components of EZJDR-diterpenoid, anthraquinone and flavonoid-could be the effective material for the treatment of HBV-HCC. This research provided valuable insights into the molecular mechanism of action underlying the therapeutic effects of EZJDR.

Free total rhubarb anthraquinones protect intestinal mucosal barrier of SAP rats via inhibiting the NLRP3/caspase-1/GSDMD pyroptotic pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhubarb is the peeled and dried roots of Rheum palmatum L. and Rheum tanguticum Maxim. ex Balf. or Rheum officinale Baill. Free total rhubarb anthraquinones (FTRAs) were isolated and extracted from rhubarb. Previous studies have revealed that the early administration of FTRAs protects the intestinal mucosal barrier in rats with severe acute pancreatitis (SAP), the mechanism of which is not yet clear. However, we observed an enhanced expression of intestinal pyroptotic factors in rats treated with SAP, which may be related to the mechanism of intestinal barrier protection by FTRAs. AIM OF THE STUDY: The main objective of this study was to investigate the mechanism by which FTRAs protect the intestinal mucosal barrier in SAP rats, focusing on the classical pyroptosis pathway. MATERIALS AND METHODS: SAP was induced in rats through retrograde injection of sodium taurocholate via the pancreaticobiliary duct. Subsequently, FTRAs (22.5, 45, and 90 mg/kg), rhubarb (900 mg/kg, positive control), and saline (control) were administered at 0 h (immediately), 12 h, and 24 h post-surgery. Pancreatic and intestinal tissue injury, positive PI staining rate, and expression levels of various factors in intestinal tissues were compared across different groups. These factors include diamine oxidase (DAO), lactate dehydrogenase (LDH), high mobility group box chromosomal protein 1(HMGB1) and pro-inflammatory factors in intestinal and serum, pyroptosis-associated factors, toll-like receptor 4 (TLR-4), nuclear factor kappa-B (NF-kB), apoptosis-associated speck-like protein (ASC), NOD-like receptor protein 3 (NLRP3), cysteine protease-1 (caspase-1) and Gasdermin (GSDMD). RESULTS: The findings indicated that FTRAs protected the damaged intestine and pancreas and restored the expression of intestinal epithelial junction proteins in SAP rats. Additionally, it reduced intestinal and serum levels of DAO, interleukin 1, interleukin 18, HMGB1, and LDH, attenuated intestinal Positive PI staining rate, and significantly decreased the expressions of TLR-4, NF-kB, ASC, NLRP3, caspase-1 and GSDMD in SAP rats. CONCLUSIONS: The results suggest that FTRAs inhibited pyroptosis through down-regulation of the NLRP3-Caspase-1-GSDMD and TLR-4- NF-kB signaling pathways of intestinal tissues., thereby protecting the intestinal barrier of SAP rats.

Cholesterol-lowering effects of rhubarb free anthraquinones and their mechanism of action.

Rhubarb free anthraquinones (RhA) have significant lipid-regulating activity. However, whether RhA monomers have a role in lipid-regulating and their mechanism of action remains unclear. Based on the cholesterol accumulated HepG2 cell model, the cholesterol-regulating effect of RhA monomers and their combinations was investigated. The expression of sterol-regulatory element binding protein 2 (SREBP2), 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR) and squalene monooxygenase (SQLE) of the model cells was analyzed to preliminarily explore the mechanism of action. After that, the liposomes of each active RhA monomer were separately prepared with the same lipid materials and the same preparation method so that each monomer has similar or equal bioavailability after oral administration to rats. Finally, the hypercholesterolemic rat model was established, and the effect of active RhA monomers loaded liposomes as well as their combinations on cholesterol-regulating was investigated and their mechanism of action was analyzed. The results showed that aloe-emodin, rhein and emodin were the main cholesterol-regulating components of RhA, and the combination of rhein and emodin showed significant cholesterol-lowering effect, which may be related to the expression of SREBP2, HMGCR and SQLE in the rat liver.

Construction of chrysophanol loaded nanoparticles with N-octyl-O-sulfate chitosan for enhanced nephroprotective effect.

Natural occurring anthraquinone like chrysophanol has been studied because of its anti-diabetic, anti-tumor, anti-inflammatory, hepatoprotective and neuroprotective properties. Nonetheless, its poor water solubility and unstable nature are big concerns in achieving efficient delivery and associated pharmacokinetic and pharmacodynamic effects. Herein, this study sought to solve the above-mentioned problem through development of chrysophanol-loaded nanoparticles to enhance the bioavailability of chrysophanol and to evaluate its anti-renal fibrosis effect in rats. After synthesis of a safe N-octyl-O-sulfate chitosan, we used it to prepare chrysophanol-loaded nanoparticles through dialysis technique before we performed and physical characterization. Also, we tested the stability of the nanoparticles for 21 days at 4 °C and room temperature (25 °C) and evaluated their pharmacokinetics and anti-renal fibrosis effect in rat model of chronic kidney disease (CKD). In terms of results, the nano-preparation demonstrated an acceptable narrow size distribution, wherein the encapsulation rate, size, polydispersed index (PDI) and electrokinetic potential at room temperature were respectively 83.41±0.89 %, 364.88±13.62 nm, 0.192±0.015 and 23.78±1.39 mV. During 21 days of storage, we observed that size of particles and electrokinetic potential altered slightly but the difference was statistically insignificant (p > 0.05). Also, in vitro release studies showed that the formulation reached 84.74 % at 24 h. Chrysophanol nanoparticles showed a 2.57-fold increase in bioavailability compared to unformulated chrysophanol. More importantly, chrysophanol nanoparticles demonstrated certain renal internalization properties and anti-renal fibrosis effects, which could ultimately result in reduced blood-urea nitrogen (BUN), kidney-injury molecule-1 (KIM-1) and serum creatinine (SCr) levels in model rats. In conclusion, the prepared chrysophanol-loaded nanoparticles potentially increased bioavailability and enhanced nephroprotective effects of chrysophanol.

9,10-Dioxoanthracenyldithiocarbamates effectively inhibit the proliferation of non-small cell lung cancer by targeting multiple protein tyrosine kinases.

Anthraquinones have attracted considerable interest in the realm of cancer treatment owing to their potent anticancer properties. This study evaluates the potential of a series of new anthraquinone derivatives as anticancer agents for non-small-cell lung cancer (NSCLC). The compounds were subjected to a range of tests to assess their cytotoxic and apoptotic properties, ability to inhibit colony formation, pro-DNA damage functions, and capacity to inhibit the activity of tyrosine kinase proteins (PTKs). Based on the research findings, it has been discovered that most active derivatives (i84, i87, and i90) possess a substantial capability to impede the viability of NSCLC while having mostly a negligible effect on the human kidney cell line. Moreover, the anthraquinones displayed pro-apoptotic and genotoxic attributes while blocking the phosphorylation of multiple PTKs. Collectively, our findings indicate that these derivatives may demonstrate promising potential as effective anticancer agents for lung cancer treatment.

Stool-softening effect and action mechanism of free anthraquinones extracted from Rheum palmatum L. on water deficit-induced constipation in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese herbal medicine, rhubarb is said to remove accumulation with purgation, clearing heat, and discharging fire. Modern pharmacology has shown that rhubarb extract has a purgative effect when given to experimental animals in an appropriate dose. However, the active components and their mechanism of action are still not clearly defined. AIM OF THE STUDY: The current research aimed to evaluate the synergistic stool-softening effects and explore the action mechanism of rhubarb free anthraquinones (RhA) and their monomers on constipation in rats. MATERIALS AND METHODS: A rat model of water deficit-induced constipation was established to induce constipation, and these rats were treated with RhA and its monomers. ELISA, histopathology, immunohistochemistry, qPCR and Western blotting based on network pharmacology and molecular docking were conducted to explore the possible mechanism of action of RhA and its monomers. RESULTS: RhA, aloe-emodin, rhein, and chrysophanol showed stool-softening activity, and the combination of aloe-emodin and rhein had the strongest softening effect on faecal pellets. Aloe-emodin, rhein, and chrysophanol significantly increased the serum levels of vasoactive intestinal peptide (VIP), motilin (MTL), and substance P (SP), upregulated the expression of VIP, cyclase-associated protein 1 (CAP1), protein kinase A (PKA), cystic fibrosis transmembrane conductance regulator (CFTR), aquaporin 3 (AQP3), aquaporin 4 (AQP4), and aquaporin 8 (AQP8), decreased the expression of epithelial sodium channel (ENaC) and Na+/H+ exchanger 3 (NHE3), and reduced the colonic tissue concentration of Na+-K+-ATPase in the constipated rats. Osmolality of colonic fluid in model rats treated by RhA, aloe-emodin, rhein, and chrysophanol was increased. CONCLUSION: Aloe-emodin, rhein, and chrysophanol were the stool-softening components of the RhA extract, and there were certain drug-interactions between the components. RhA upregulated VIP expression, activated the cyclic adenosine monophosphate protein kinase A (cAMP/PKA) pathway, and further stimulated CFTR expression while inhibiting NHE3 and ENaC expression, resulting in a hypertonic state in the colonic lumen. Water transport could then be driven by an osmotic gradient, which in turn led to the upregulation of AQP3, AQP4, and AQP8 expression. In addition, RhA likely improved gastrointestinal motility by increasing serum VIP, SP, and MTL concentrations, thus promoting faecal excretion.

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.

Antagonism of androgen receptor signaling by aloe-emodin.

Over the past decades, androgen receptor (AR) signaling has been a key driver of both primary and recurrent prostate cancer. In this work, aloe-emodin was identified as a novel AR antagonist, effectively inhibiting AR signaling. Firstly, aloe-emodin can inhibit LNCaP cell growth by promoting apoptosis. Then, the results of Western blot and quantitative real-time PCR further confirmed that aloe-emodin modulated AR protein levels by promoting AR proteasomal degradation, and also inhibited the transcription of the AR downstream target genes, including PSA, KLK2, and TMPRSS2. Furthermore, the result of immunofluorescence showed that aloe-emodin prevented the nuclear translocation of AR. Molecular docking and molecular dynamics simulation suggested that aloe-emodin combined with AR to form stable complexes, which might explain that aloe-emodin prevented the translocation of AR from the cytoplasm to the nucleus by affecting the ligand binding of AR. Therefore, aloe-emodin as a novel AR antagonist may play a crucial role in promoting cancer prevention or complementing pharmacological therapies in the treatment of prostate cancer.

Rhein attenuates cerebral ischemia-reperfusion injury via inhibition of ferroptosis through NRF2/SLC7A11/GPX4 pathway.

BACKGROUND: Ischemic stroke, a major cause of death and disability worldwide, results from reduced blood flow to the brain, leading to irreversible neuronal damage. Recent evidence suggests that ferroptosis, a form of regulated cell death, plays a critical role in the pathogenesis of ischemic stroke. Rhein, a natural anthraquinone compound, has demonstrated neuroprotective effects; However, its role in ferroptosis and the underlying mechanisms remain unclear. Here, we investigated the protective effects of Rhein against ischemia/reperfusion (I/R) injury in a rat model of middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cells. Rhein treatment dose-dependently ameliorated neurological deficits, reduced infarct volume, and attenuated blood-brain barrier (BBB) disruption in the MCAO model. Furthermore, Rhein suppressed oxidative stress, intracellular ROS generation, and ferroptosis-related protein expression in both in vivo and in vitro models. Mechanistically, Rhein protected against OGD/R-induced HT22 cell injury by regulating the NRF2/SLC7A11/GPX4 signaling pathway. This effect was abolished upon NRF2 inhibition, suggesting that Rhein's neuroprotective action is NRF2-dependent. Molecular docking and microscale thermophoresis analyses further supported the direct interaction between Rhein and the ferroptosis-related protein NRF2. Collectively, our findings reveal that Rhein confers neuroprotection against cerebral I/R injury by inhibiting ferroptosis via the NRF2/SLC7A11/GPX4 axis, providing a potential therapeutic avenue for ischemic stroke. AIMS: To investigate the neuroprotective effects of Rhein, a natural anthraquinone compound, against ischemia/reperfusion (I/R) injury and elucidate the underlying mechanisms involving ferroptosis and the NRF2/SLC7A11/GPX4 pathway. METHODS: A rat model of middle cerebral artery occlusion (MCAO) was employed for in vivo assessments, while oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cells were used as an in vitro model. Comprehensive analyses, including neurological score assessment, triphenyl tetrazolium chloride staining, Evans Blue leakage assay, intracellular ROS detection, MTT assay, dual-luciferase reporter assay, oxidative stress and Fe2+ content assessment, immunofluorescence, Western blot, flow cytometry, molecular docking, and microscale thermophoresis, were performed to evaluate the effects of Rhein on I/R injury and ferroptosis. RESULTS: Rhein conferred dose-dependent neuroprotection against cerebral I/R injury, reducing infarct volume and blood-brain barrier (BBB) disruption in the MCAO model. In both in vivo and in vitro models, Rhein suppressed oxidative stress, intracellular ROS generation, and ferroptosis-related protein expression. Furthermore, Rhein protected HT22 cells from OGD/R-induced injury by regulating the NRF2/SLC7A11/GPX4 signaling pathway, with NRF2 inhibition abolishing these therapeutic effects. Molecular docking and microscale thermophoresis analyses supported a direct interaction between Rhein and NRF2, a ferroptosis-related protein. CONCLUSION: Rhein attenuates cerebral I/R injury by inhibiting ferroptosis via the NRF2/SLC7A11/GPX4 axis, highlighting its potential as a therapeutic agent for ischemic stroke.

Rhein alleviates advanced glycation end products (AGEs)-induced inflammatory injury of diabetic cardiomyopathy in vitro and in vivo models.

In diabetic patients, diabetic cardiomyopathy (DCM) is one of the most common causes of death. The inflammatory response is essential in the pathogenesis of DCM. Rhein, an anthraquinone compound, is extracted from the herb rhubarb, demonstrating various biological activities. However, it is unclear whether rhein has an anti-inflammatory effect in treating DCM. In our research, we investigated the anti-inflammatory properties as well as its possible mechanism. According to the findings in vitro, rhein could to exert an anti-inflammatory effect by reducing the production of NO, TNF-α, PGE2, iNOS, and COX-2 in RAW264.7 cells that had been stimulated with advanced glycosylation end products (AGEs). In addition, rhein alleviated H9C2 cells inflammation injury stimulated by AGEs/macrophage conditioned medium (CM). In vivo have depicted that continuous gavage of rhein could improve cardiac function and pathological changes. Moreover, it could inhibit the accumulation of AGEs and infiltration of inflammatory factors inside the heart of rats having DCM. Mechanism study showed rhein could suppress IKKß and IκB phosphorylation via down-regulating TRAF6 expression to inhibit NF-κB pathway in AGEs/CM-induced H9C2 cells. Moreover, the anti-inflammation effect of rhein was realized through down-regulation phosphorylation of JNK MAPK. Furthermore, we found JNK MAPK could crosstalk with NF-κB pathway by regulating IκB phosphorylation without affecting IKKß activity. And hence, the protective mechanism of rhein may involve the inhibiting of the TRAF6-NF/κB pathway, the JNK MAPK pathway, and the crosstalk between the two pathways. These results suggested that rhein may be a promising drug candidate in anti-inflammation and inflammation-related DCM therapy.

Diacerein versus non-steroidal anti-inflammatory drugs in the treatment of knee osteoarthritis: a meta-analysis.

BACKGROUND: Knee osteoarthritis (KOA) is a common musculoskeletal condition affecting millions of people worldwide and posing a significant challenge to clinicians and researchers. Emerging evidence suggests that the multifaceted symptomatology of KOA may be alleviated by diacerein. With this in mind, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of diacerein in patients with KOA. METHODS: We systematically searched Embase, PubMed, Cochrane Library, Web of Science, Chinese Biomedical Literature Database (CBM), Wanfang Database (WanFang), China National Knowledge Infrastructure (CNKI), and China Science and Technology Journal Database (VIP) from their inception to August 2022 for randomized controlled trials (RCTs) of diacerein intervention on patients with KOA. Two reviewers independently performed the selection of eligible studies and the extraction of relevant data. The meta-analysis was performed using RevMan 5.4 and R 4.1.3 software tools. Depending on the type of outcome indicator selected, summary measures were expressed as mean differences (MD), standardized mean differences (SMD), or odds ratio (OR) with 95% confidence intervals (CI). RESULTS: Twelve RCTs with 1732 patients were included. The results revealed that diacerein had comparable efficacy to non-steroidal anti-inflammatory drugs (NSAIDs) in reducing pain indicators such as Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (SMD = 0.09, 95% CI [-0.10, 0.28], P = 0.34) and visual analogue scale (VAS) (SMD = -0.19, 95% CI [-0.65, 0.27], P = 0.42). However, diacerein outperformed NSAIDs in terms of global efficacy assessment by both patients and investigators (patients: 1.97, 95% CI [1.18, 3.29], P = 0.01; investigator: 2.18, 95% CI [0.99, 4.81], P = 0.05) at the end of treatment and sustained effectiveness in reducing WOMAC score and VAS score at four weeks after treatment. Moreover, there was no significant difference in adverse events incidence between the diacerein and NSAID groups. However, the GRADE evaluation indicated that the majority of the evidence quality was low. CONCLUSIONS: The results of this study suggest that diacerein could potentially be considered as a pharmacological agent with significant efficacy for the treatment of patients suffering from KOA, offering a potential alternative treatment strategy for those patients contraindicated to NSAIDs. However, further high-quality studies with longer follow-up are needed to make more informed decisions about its efficacy in the treatment of KOA.

Towards effective natural anthraquinones to mediate antimicrobial photodynamic therapy of cutaneous leishmaniasis.

BACKGROUND: Cutaneous leishmaniasis (CL) is an important tropical neglected disease with broad geographical dispersion. The lack of effective drugs has raised an urgent need to improve CL treatment, and antimicrobial photodynamic therapy (APDT) has been investigated as a new strategy to face it with positive outcomes. Natural compounds have emerged as promising photosensitizers (PSs), but their use in vivo remains unexplored. PURPOSE: In this work, we investigated the potential of three natural anthraquinones (AQs) on CL induced by Leishmania amazonensis in BALB/c mice. STUDY DESIGN/METHODS: ANIMALS WERE INFECTED AND RANDOMLY DIVIDED INTO FOUR GROUPS: CG (control, non-treated group), G5ClSor-gL (treated with 5-chlorosoranjidiol and green LED, 520±10 nm), GSor-bL and GBisor-bL (treated with soranjidiol and bisoranjidiol, respectively, exposed to violet-blue LED, 410±10 nm). All AQs were assayed at 10 µM and LEDs delivered a radiant exposure of 45 J/cm2 with an irradiance of 50 mW/cm2. We assessed the parasite burden in real time for three consecutive days. Lesion evolution and pain score were assessed over 3 weeks after a single APDT session. RESULTS: G5ClSor-gL was able to sustain low levels of parasite burden over time. Besides, GSor-bL showed a smaller lesion area than the control group, inhibiting the disease progression. CONCLUSION: Taken together, our data demonstrate that monoAQs are promising compounds for pursuing the best protocol for treating CL and helping to face this serious health problem. Studies involving host-pathogen interaction as well as monoAQ-mediated PDT immune response are also encouraged.

Chrysophanol alleviates acute lung injury caused by Klebsiella pneumoniae infection by inhibiting pro-inflammatory cytokine production.

Acute lung injury (ALI) caused by acute bacterial infection remains a common life-threatening lung disease. An increased inflammatory response is the basis for the occurrence and development of ALI. Most antibiotics can only reduce the bacterial load but do not protect from lung damage because of an excessive immune response. Chrysophanol (chrysophanic acid, Chr), as a natural anthraquinone extracted from Rheum palmatum L., has various biological functions, including anti-inflammatory, anti-cancer activities, and ameliorative effects on cardiovascular diseases. Considering these properties, we investigated the effect of Chr in Klebsiella pneumoniae (KP)-induced ALI mice and its potential mechanism. Our results showed that Chr had protective effects against KP-infected mice, including increased survival rate, decreased bacterial burden, reduced recruitment of immune cells, and reduced reactive oxygen species level of lung macrophages. Chr reduced the expression of inflammatory cytokines by inhibiting the toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) signaling pathway and inflammasome activation and strengthening autophagy. Overactivation of the TLR4/NF-κB signaling pathway by the activator Neoseptin 3 led to Chr losing control of inflammatory cytokines in cells, resulting in increased cell death. Similarly, overactivation of the c-Jun N-terminal kinase signaling pathway using the activator anisomycin resulted in Chr losing its inhibitory effect on NOD-like receptor thermal protein domain associated protein 3 (NFRP3) inflammasome activation, and cell viability was reduced. In addition, autophagy was blocked by siBeclin1, so Chr could not reduce inflammatory factors, and cell viability was markedly inhibited. Collectively, this work unravels the molecular mechanism underpinning Chr-alleviated ALI via inhibiting pro-inflammatory cytokines. Thus, Chr is a potential therapeutic agent for KP-induced ALI.

A paper-based colorimetric method for monitoring of lithium therapeutic levels.

Lithium remains the "gold standard" for both acute and maintenance treatment of bipolar disorder (BD), a serious life-long condition characterised by recurrent episodes of depressed and manic mood states. However, lithium has a very narrow therapeutic range (0.4-1.2 mmol L-1) and despite its effectiveness in preventing and reducing mood swings and suicidality, it is a potentially hazardous drug. While it is crucial to carefully monitor lithium plasma levels, the current techniques of lithium monitoring are cumbersome and require frequent blood tests with the consequent discomfort which results in patients evading treatment. Therefore, development of low-cost and facile lithium detection techniques that can be translated into point-of-care devices for personal monitoring will be a major advance in the management of BD. In the current study, we present colorimetric determination of lithium therapeutic levels utilizing test paper strips, based on its reaction with the chromogenic agent Quinizarin. Exposure of Quinizarin-dipped test papers to samples of interstitial fluid (ISF) or dH2O spiked with therapeutic concentrations of lithium resulted in colour changes that were monitored using optical spectroscopy. The acquired spectra from the test papers show spectral variations which are related to lithium concentrations in spiked samples of dh2O and artificial ISF with a coefficient of determination (R2) of 0.9 and 0.8, respectively. Altogether, the spectrophotometric and colorimetric analyses demonstrated strong correlations between the observed colour changes and the concentrations of lithium present in the sample. Therefore, this study has demonstrated that Quinizarin-treated cellulose-based papers are suitable for the precise detection of changes in lithium therapeutic levels. This method is simple and very convenient and serves as a foundation for the future development of a paper-based colorimetric sensor for monitoring of lithium therapeutic levels in ISF and other non-invasive biological fluids.

Optimal timing of free total rhubarb anthraquinones on immune regulation in rats with severe acute pancreatitis.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhubarb is the peeled and dried root of Rheum palmatum L., Rheum tanguticum Maxim. ex Balf. or Rheum officinale Baill. Free total rhubarb anthraquinones (FTRAs) isolated and extracted from rhubarb display the beneficial effects of anti-inflammation and immunological modulation. The timing of immune regulation is a major problem in the immunotherapy for severe acute pancreatitis (SAP). several studies reported that FTRAs could reduce systemic inflammatory responses by inhibiting early immune overactivity in the gut in rats with SAP. But, the optimal timing of rhubarb and FTRAs administration is not clear in clinical practice. Therefore, the time window for the best efficacy of rhubarb and FTRAs in the treatment of SAP patients should be further elucidated. AIM OF THE STUDY: The main purpose of the present study was to evaluate the efficacy and optimal timing of immune modulation with FTRAs in the treatment of SAP in rats. MATERIALS AND METHODS: FTRAs (22.5, 45 and 90 mg/kg), Rhubarb (RHU) (900 mg/kg, positive control) or normal saline (vehicle control) were initiated at 0 (immediately), 48 and 72 h every 12 h for three times in total. The therapeutic effects of FTRAs and RHU on pancreas and intestinal tissues injury, secondary infection with pseudomonas aeruginosa (PA), amylase, lipase, D-lactic acid (DLA), endotoxin (ET), proinflammatory and anti-inflammatory cytokines, macrophages, dendritic cells and regulatory T cells (Tregs) in the blood, small intestine and/or mesenteric lymph node (MLN) were determined in rats with SAP after treatment. RESULTS: The results showed that administration of FTRAs at 0 h was superior to 48 h and 72 h, which significantly protected the injury of pancreas and intestinal tissues, reduced the mortality induced by secondary infection with PA, decreased the levels of amylase, lipase, DLA, ET, tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), IL-6, IL-8, IL-18 and Tregs, and increased the levels of IL-4, sTNF-αR, macrophages and dendritic cells, secretary immunoglobulin A (SIgA) in the blood and/or small intestinal tissues in rats with SAP. CONCLUSIONS: In conclusion, our studies indicate that the treatment window of FTRAs for SAP is within 48 h of development, administration of FTRAs at the early stage (0 h, immune overreaction period) was the optimal time and superior to that of 48 h and 72 h for its therapeutic efficacy. The earlier the administration of FTRAs, the better the therapeutic efficacy. Therefore, our data may provide a scientific rationale for the clinical application and optimal timing of FTRAs in the treatment of SAP.

Potential Medicinal Value of Rhein for Diabetic Kidney Disease.

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