Artesunate Ameliorates Functional Limitations in Freund’s Complete Adjuvant-Induced Monoarthritis in Rat by Maintaining Oxidative Homeostasis and Inhibiting COX-2 Expression

The potential efficacy of sesquiterpenes and their derivatives in treating rheumatoid arthritis: A systematic review

Rheumatoid arthritis (RA) is an autoimmune disorder primarily targeting peripheral joints. The global prevalence of RA is increasing, posing a significant challenge in patient care management. Despite therapeutic advancements, their inherent limitations highlight the need for further research on safer treatment interventions. Among potential candidates, sesquiterpenes, a subclass of plant secondary metabolites composed of three isoprene units, have exhibited remarkable efficacy in treating various inflammatory disorders, including RA. In this systematic review, we summarized the treatment evidence of sesquiterpenes and their derivatives on RA. Specific major sesquiterpenoids have been discussed in detail, as well as the possible mechanisms by which cells and chemical messengers are involved in treating RA. Our review indicated that sesquiterpenes are potential novel, bioactive compounds for RA prevention and treatment strategies.

Artesunate alleviates intestinal ischemia/reperfusion induced acute lung injury via up-regulating AKT and HO-1 signal pathway in mice

Acute Lung injury (ALI) is a common complication following intestinal ischemia/reperfusion (II/R) injury that can lead to acute respiratory distress syndrome (ARDS) a fatal illness for there is no specific therapy. The semisynthetic artemisinin Artesunate (Art) extracted from Artemisia annua has been found lots of pharmaceutical effects such as anti-malaria, anti-inflammatory, and anti-apoptosis. This study aimed to investigate the effect of Artesunate on intestinal ischemia/reperfusion and the mechanism of how Artesunate works in mice. To establish the II/R model, the C57BL/c mice were subjected to occlude superior mesenteric artery (SMA) for 45 min and 120 min reperfusion, and the lung tissue was collected for examination. Severe lung injury occurred during the II/R, meanwhile Art pretreatment decreased the lung injury score, wet/dry ratio, the level of MDA, MPO, IL-1β, TNFα, CXCL1, MCP-1, the TUNEL-positive cells, Bax and Cleaved-Caspase3 protein expression obviously, and increased the activity of SOD and the expression of Bcl-2. In addition, the protein of P-AKT and HO-1 were upregulated during the Art pretreatment. Then the AKT inhibitor Triciribin and HO-1 inhibitor Tin-protoporphyrin IX were administered which reversed the protein expression of apoptosis, AKT and HO-1. Our study suggests that Art mitigated the II/R induced acute lung injury by targeting the oxidative stress, inflammatory response and apoptosis which is associated with the activating of AKT and HO-1, providing novel insights into the therapeutic candidate for the treatment of II/R induced acute lung injury.

Chronic Pain after Bone Fracture: Current Insights into Molecular Mechanisms and Therapeutic Strategies

Bone fracture following traumatic injury or due to osteoporosis is characterized by severe pain and motor impairment and is a major cause of global mortality and disability. Fracture pain often originates from mechanical distortion of somatosensory nerve terminals innervating bones and muscles and is maintained by central sensitization. Chronic fracture pain (CFP) after orthopedic repairs is considered one of the most critical contributors to interference with the physical rehabilitation and musculoskeletal functional recovery. Analgesics available for CFP in clinics not only have poor curative potency but also have considerable side effects; therefore, it is important to further explore the pathogenesis of CFP and identify safe and effective therapies. The typical physiopathological characteristics of CFP are a neuroinflammatory response and excitatory synaptic plasticity, but the specific molecular mechanisms involved remain poorly elucidated. Recent progress has deepened our understanding of the emerging properties of chemokine production, proinflammatory mediator secretion, caspase activation, neurotransmitter release, and neuron-glia interaction in initiating and sustaining synaptogenesis, synaptic strength, and signal transduction in central pain sensitization, indicating the possibility of targeting neuroinflammation to prevent and treat CFP. This review summarizes current literature on the excitatory synaptic plasticity, microgliosis, and microglial activation-associated signaling molecules and discusses the unconventional modulation of caspases and stimulator of interferon genes (STING) in the pathophysiology of CFP. We also review the mechanisms of action of analgesics in the clinic and their side effects as well as promising therapeutic candidates (e.g., specialized pro-resolving mediators, a caspase-6 inhibitor, and a STING agonist) for pain relief by the attenuation of neuroinflammation with the aim of better managing patients undergoing CFP in the clinical setting.

Artesunate Therapy Alleviates Fracture-Associated Chronic Pain After Orthopedic Surgery by Suppressing CCL21-Dependent TREM2/DAP12 Inflammatory Signaling in Mice

Chronic pain after bone fracture and orthopedic surgery is often refractory to most analgesics currently in use, thus emphasizing the urgent need for improved therapeutic medications. Chemokine-dependent neuroinflammation is critical for excitatory synaptic plasticity and central nociception sensitization. Recent studies have focused on the inhibition of inflammatory responses by artesunate, the first anti-malaria drug extracted from artemisinin. The present study investigated the analgesic effects and potential targets of artesunate in a mouse model of chronic pain induced by tibial fracture and orthopedic surgery. Three injections of artesunate were intrathecally administered on a daily basis from days 4 to 6 after fracture. We reported that repetitive exposure to artesunate (10 and 100 μg but not 1 μg) dose-dependently prevented fracture-induced mechanical and cold allodynia. Moreover, single intrathecal injection of artesunate (100 μg) alleviated the established chronic pain on day 14 after fracture surgery. Intraperitoneal artesunate (10 and 50 mg kg^-1) therapy was effective against chronic fracture pain. Intriguingly, artesunate inhibited the upregulation of spinal chemokine CCL21, triggering receptor expressed on myeloid cells 2 (TREM2) and DNAX-activating protein of 12 kDa (DAP12) expressions and microglia activation in fracture mice. Furthermore, spinal CCL21 neutralization attenuated the severity of fracture-associated post-surgical pain. Exogenous CCL21-induced acute inflammatory pain was impaired by artesunate therapy. Additionally, the pharmacological blockage of TREM2 reduced recombinant CCL21-elicited behavioral hypernociception. The present findings demonstrate that artesunate therapy reduces the initiation and maintenance of fracture-associated chronic postoperative pain by inhibiting CCL21-dependent TREM2/DAP12 inflammatory signaling and microglia activation, thus suggesting that artesunate could emerge as a therapeutic strategy for fracture pain management.

Artesunate Alleviates Paclitaxel-Induced Neuropathic Pain in Mice by Decreasing Metabotropic Glutamate Receptor 5 Activity and Neuroinflammation in Primary Sensory Neurons

Experimental studies on the pathogenetic process of paclitaxel-induced neuropathic pain (PINP) have been initially carried out, but PINP still has no effective therapy. Recently reported studies have highlighted the involvement of glutamate receptors and neuroinflammation in peripheral and central nociceptive transmission in PINP. Artesunate is a first-line antimalarial drug with established efficacy in alleviating pain in a variety of pathologies. The current work assessed whether artesunate inhibits PINP by modulating metabotropic glutamate receptor 5 (mGluR5) and neuroinflammation in mice. The anti-hyperalgesic effect of artesunate was verified by assessing mechanical frequency and thermal latency in the paw withdrawal test as well as spontaneous pain. The expression levels of mGluR5, pain-related receptors and neuroinflammatory markers in dorsal root ganglion (DRG) were examined. In addition, treatment with CHPG and 2-methyl-6-(phenyl ethynyl) pyridine (MPEP) (mGluR5 agonist and antagonist, respectively) was performed to determine mGluR5’s role in the anti-hyperalgesic properties of artesunate. We demonstrated artesunate prevented PINP in a dose-dependent manner, while exerting a clear anti-hyperalgesic effect on already existing PINP. Artesunate normalized paclitaxel-related expression changes in DRG mGluR5, NR1, and GluA2, as well as six paclitaxel related neuroinflammation markers. Intrathecal application of MPEP treated PINP by reversing NR1 and GluA2 expression changes but had no effects on chemokines and inflammatory factors. Furthermore, artesunate treatment reversed acute pain following CHPG application. In conclusion, this study revealed that artesunate alleviates paclitaxel-induced hyperalgesia and spontaneous pain by decreasing DRG mGluR5 expression and neuroinflammation in the mouse model of PINP.

New Insights into Artesunate as a Pleiotropic Regulator of Innate and Adaptive Immune Cells

Artesunate, one of the derivatives of artemisinin (“qinghaosu” in Chinese), is known as an antimalarial drug with high efficiency and low toxicity. Of interest, emerging evidences suggest that artesunate also possesses an immunomodulatory effect during innate and adaptive immune responses in cell types and context-dependent manner. Although it shows promising application in many diseases, such as inflammatory diseases, hypersensitivity, autoimmune diseases, and cancers, little is known about underlying molecular. In this review, we summarize recent advances of how artesunate regulates innate and adaptive immune cells. In addition, its potential application in immune-related diseases is also highlighted.

Artesunate Reduces Remifentanil-induced Hyperalgesia and Peroxiredoxin-3 Hyperacetylation via Modulating Spinal Metabotropic Glutamate Receptor 5 in Rats

The experimental investigations on the pathogenesis of remifentanil-induced hyperalgesia (RIH) have been primarily conducted, but the effective treatment of RIH remains unclear. Recent reports highlight the necessity of ionotropic glutamate receptors in oxidative damage in spinal nociceptive transduction. Artesunate, the 1st-line anti-malaria drug, has been identified to be valid in removing superoxide in several pathological conditions. This study evaluated whether artesunate inhibits RIH via regulating metabotropic glutamate receptor 5 (mGluR5) and mitochondrial antioxidant enzyme peroxiredoxin-3 in rats. Artesunate was injected intrathecally 10 min before intravenous infusion of remifentanil (1 μg·kg^-1·min^-1 for 60 min) in rats. The antinociception of artesunate was verified by assessment of paw withdrawal mechanical threshold and paw withdrawal thermal latency. Spinal mGluR5 expression and peroxiredoxin-3 hyperacetylation were examined. Also, both the mGluR5 agonist DHPG and antagonist MPEP were utilized to explore the involvement of mGluR5 in the anti-hyperalgesic property of artesunate. Here, we found that artesunate (10 μg and 100 μg but not 1 μg) prevented RIH in a dose-dependent manner. Artesunate reduced remifentanil-related spinal over-expression of mGluR5 gene and protein, and hyperacetylation of peroxiredoxin-3. Intrathecal application of MPEP (10 nmol and 100 nmol but not 1 nmol) inhibited behavioral RIH and peroxiredoxin-3 acetylation. Moreover, hyperalgesia and peroxiredoxin-3 hyperacetylation were attenuated after the combination of artesunate (1 μg) and MPEP (1 nmol). Additionally, artesunate treatment reversed acute pain and peroxiredoxin-3 hyperacetylation following spinal exposure to DHPG. In conclusion, intrathecal injection of artesunate impairs RIH by down-regulating spinal mGluR5 expression and peroxiredoxin-3 hyperacetylation-mediated oxidative stress in rats.

The immunosuppressive activity of artemisinin-type drugs towards inflammatory and autoimmune diseases

The sesquiterpene lactone artemisinin from Artemisia annua L. is well established for malaria therapy, but its bioactivity spectrum is much broader. In this review, we give a comprehensive and timely overview of the literature regarding the immunosuppressive activity of artemisinin-type compounds toward inflammatory and autoimmune diseases. Numerous receptor-coupled signaling pathways are inhibited by artemisinins, including the receptors for interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), β3-integrin, or RANKL, toll-like receptors and growth factor receptors. Among the receptor-coupled signal transducers are extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), AKT serine/threonine kinase (AKT), mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase (ERK) kinase (MEK), phospholipase C γ1 (PLCγ), and others. All these receptors and signal transduction molecules are known to contribute to the inhibition of the transcription factor nuclear factor κ B (NF-κB). Artemisinins may inhibit NF-κB by silencing these upstream pathways and/or by direct binding to NF-κB. Numerous NF-κB-regulated downstream genes are downregulated by artemisinin and its derivatives, for example, cytokines, chemokines, and immune receptors, which regulate immune cell differentiation, apoptosis genes, proliferation-regulating genes, signal transducers, and genes involved in antioxidant stress response. In addition to the prominent role of NF-κB, other transcription factors are also inhibited by artemisinins (mammalian target of rapamycin [mTOR], activating protein 1 [AP1]/FBJ murine osteosarcoma viral oncogene homologue [FOS]/JUN oncogenic transcription factor [JUN]), hypoxia-induced factor 1α (HIF-1α), nuclear factor of activated T cells c1 (NF-ATC1), Signal transducers and activators of transcription (STAT), NF E2-related factor-2 (NRF-2), retinoic-acid-receptor-related orphan nuclear receptor γ (ROR-γt), and forkhead box P-3 (FOXP-3). Many in vivo experiments in disease-relevant animal models demonstrate therapeutic efficacy of artemisinin-type drugs against rheumatic diseases (rheumatoid arthritis, osteoarthritis, lupus erythematosus, arthrosis, and gout), lung diseases (asthma, acute lung injury, and pulmonary fibrosis), neurological diseases (autoimmune encephalitis, Alzheimer's disease, and myasthenia gravis), skin diseases (dermatitis, rosacea, and psoriasis), inflammatory bowel disease, and other inflammatory and autoimmune diseases. Randomized clinical trials should be conducted in the future to translate the plethora of preclinical results into clinical practice.

Artesunate inhibits osteoclastogenesis through the miR-503/RANK axis

Osteoporosis is a metabolic bone disease that is characterized by decreased bone density and strength due to excessive loss of bone protein and mineral content, which can be induced by increased osteoclast activity. Developing agents targeting osteoclast activation is considered to be the most effective method to reverse bone destruction and alleviate the pain caused by osteoporosis. MTT assay was conducted to detect the cell viability after artesunate treatment of RAW264.7 cells. TRACP staining and pit formation assays were performed to examine the TRACP-positive cells and pit-forming activity of osteoclasts. qRT-PCR and Western blot analysis were performed to assess the mRNA and protein expression levels of the osteoclastogenesis-related genes NFATc1, TRAP, and cathepsin k. The protein levels of RANK, p-Akt, p-p38, and p-ERK were examined by Western blotting. Luciferase reporter assay was conducted to determine whether miR-503 targeted RANK directly. Artesunate inhibited TRACP-positive cells and the pit-forming activity of osteoclasts. However, artesunate increased the expression of miR-503. Artesunate suppressed osteoclastogenesis-related gene expression and RANKL-induced activation of MAPKs and the AKT pathway. In addition, miR-503 inhibited RANK expression by directly targeting RANK during osteoclast differentiation. Artesunate inhibited osteoclastogenesis and osteoclast functions in vitro by regulating the miR-503/RANK axis and suppressing the MAPK and AKT pathways, which resulted in decreased expression of osteoclastogenesis-related markers.

Artesunate suppresses inflammation and oxidative stress in a rat model of colorectal cancer

Anti-inflammatory drugs are well known to reduce the risk of colon cancer and prophylactic use of such agents is gaining acceptance as a cancer prevention therapy. As artesunate, an antimalarial drug, has been shown to exhibit chemopreventive properties, the present study was carried out to evaluate its inhibitory effect on oxidative stress and inflammation in a rat model of colon carcinogenesis. A chemical carcinogen, 1,2-dimethylhydrazine was injected twice at an interval of 1 week to induce preneoplastic lesions in the colon and the parameters indicating oxidative stress and inflammation were evaluated after 8 weeks. Artesunate (50 and 150 mg/kg) and aspirin (60 mg/kg) were administered orally throughout the study. Analysis of colon tissue revealed that both the drugs preserved histoarchitecture, inhibited cellular influx, decreased the levels of oxidative stress and inflammatory markers, downregulated cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor κB, and interleukin 1β in comparison to the experimental control. Suppression of oxidative stress and pro-inflammatory signaling by both the drugs were found to contribute to inhibition of colon carcinogenesis. The protection afforded by these drugs was found to be comparable. Our study shows that like aspirin, use of artesunate could also reduce the risk of colon cancer and it has a potential for further evaluation for the treatment purpose.

Artesunate alleviates interleukin‑1β‑induced inflammatory response and apoptosis by inhibiting the NF‑κB signaling pathway in chondrocyte‑like ATDC5 cells, and delays the progression of osteoarthritis in a mouse model

Osteoarthritis (OA) is a progressive and degenerative joint disorder that is highly prevalent worldwide and for which there is currently no effective medical therapy. Artesunate (ART), a natural compound used to treat malaria, possesses diverse biological properties, including the regulation of inflammation and apoptosis in various cells; however, its role in OA remains unclear. The aim of the present study was to investigate the effects of ART on interleukin (IL)‑1β‑induced chondrocyte‑like ATDC5 cells and in an OA mouse model. The results revealed that ART dose‑dependently relieved the inhibitory effect of IL‑1β on cell viability. Moreover, ART significantly reduced the overexpression of matrix metalloproteinase (MMP)‑3, MMP‑13, a disintegrin and metalloproteinase with thrombospondin motifs‑5 and cyclooxygenase‑2 at both the gene and protein levels in chondrocyte‑like ATDC5 cells stimulated by IL‑1β. Furthermore, ART decreased the expression of pro‑apoptotic Bax, cleaved caspase‑3 and cleaved caspase‑7 in a dose‑dependent manner, and increased the expression of the anti‑apoptotic factor Bcl‑2. These changes were mediated by the inhibitory effect of ART on the nuclear factor‑κB signaling pathway, defined as repression of the phosphorylation of IκBα and p65, and improved redistribution of p65. Additionally, ART blocked the advancement of the calcified cartilage zone and the loss of proteoglycan, and lowered histological scoring of OA in a mouse model. Taken together, these results indicate that ART may be of value as a therapeutic agent for OA.

A novel function of artesunate on inhibiting migration and invasion of fibroblast-like synoviocytes from rheumatoid arthritis patients

Introduction

Anti-malarial drug artesunate can suppress inflammation and prevent cartilage and bone destruction in collagen-induced arthritis model in rats—suggesting it may be a potent drug for rheumatoid arthritis (RA) therapy. We aimed to investigate its effect on the invasive property of fibroblast-like synoviocytes (FLS) from patients with RA.

Methods

Synovial tissues were obtained by closed needle biopsy from active RA patients, and FLS were isolated and cultured in vitro. RA-FLS were treated with artesunate at various concentrations, while methotrexate or hydroxychloroquine was employed as comparator drugs. Cell viability, proliferation, cell cycle, apoptosis, migration, invasion, and pseudopodium formation of RA-FLS were assessed by CCK-8 assays, EdU staining, Annexin V-FITC/PI staining, transwell assays, or F-actin staining, respectively. Further, relative changes of expressed proteases were analyzed by Proteome profiler human protease array and verified by quantitative real-time PCR (qPCR), Western blot, and ELISA. The expression of signaling molecules of MAPK, NF-κB, AP-1, and PI3K/Akt pathways were measured by qPCR and Western blot. PDK-1 knockdown by specific inhibitor AR-12 or siRNA transfection was used to verify the pharmacological mechanism of artesunate on RA-FLS.

Results

Artesunate significantly inhibited the migration and invasion of RA-FLS in a dose-dependent manner with or without TNF-α stimulation. The effect was mediated through artesunate inhibition of MMP-2 and MMP-9 production, and pre-treatment with exogenous MMP-9 reversed the inhibitory effect of artesunate on RA-FLS invasion. Artesunate had a stronger inhibitory effect on migration and invasion of RA-FLS as well as greater anti-inflammatory effect than those of hydroxychloroquine. Similar inhibitory effect was detected between artesunate and methotrexate, and synergy was observed when combined. Mechanistically, artesunate significantly inhibited PDK-1 expression as well as Akt and RSK2 phosphorylation—in a similar manner to PDK-1-specific inhibitor AR-12 or PDK-1 knockdown by siRNA transfection. This inhibition results in suppression of RA-FLS migration and invasion as well as decreased MMP-2 and MMP-9 expression.

Conclusions

Our study demonstrates artesunate is capable of inhibiting migration and invasion of RA-FLS through suppression of PDK1-induced activation of Akt and RSK2 phosphorylation—suggesting that artesunate may be a potential disease-modifying anti-rheumatic drug for RA.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1935-6) contains supplementary material, which is available to authorized users.

Modulation of Autophagy for Controlling Immunity

Autophagy is an essential process that maintains physiological homeostasis by promoting the transfer of cytoplasmic constituents to autophagolysosomes for degradation. In immune cells, the autophagy pathway plays an additional role in facilitating proper immunological functions. Specifically, the autophagy pathway can participate in controlling key steps in innate and adaptive immunity. Accordingly, alterations in autophagy have been linked to inflammatory diseases and defective immune responses against pathogens. In this review, we discuss the various roles of autophagy signaling in coordinating immune responses and how these activities are connected to pathological conditions. We highlight the therapeutic potential of autophagy modulators that can impact immune responses and the mechanisms of action responsible.

Gastroprotective effects of oleuropein and thymol on indomethacin-induced gastric ulcer in Sprague-Dawley rats

Ethnopharmacological studies demonstrated that thymol (Thym) and oleuropein (Ole) have therapeutic potential for gastric ulcers. The molecular mechanism underlying the gastroprotective effects of these compounds have not been elucidated yet especially for their individual and combination use at high dose. Therefore, this study was conducted to explore their gastroprotective mechanisms on indomethacin (Indo)-induced gastric ulcer model. Ole (50,100, 250, and 500 mg/kg) and Thym (50,100, 200, and 500 mg/kg) were orally administered to the rats 10 min before the induction of ulcer with Indo. The combination of 500 mg/kg doses of Ole and Thym were applied. The gastric mucosa was evaluated histopathologically. Moreover, TAC/TOS, tumor necrosis factor-alpha (TNF-α), prostaglandin E₂ (PGE₂), endothelial nitric oxide synthase (eNOS), and caspase-3 levels were assessed by ELISA and the caspase-3 and TNF-α expressions were quantified by qRT-PCR. Indo-induced histopathological changes while Ole and Thym pretreatment prevented these effects. Unlike the 500 mg/kg dose of Ole treatment, the 500 mg/kg dose of Thym administration enhanced these damages. The decreased TAC, PGE₂ levels and increased TOS, eNOS, TNF-α, caspase-3 levels were obtained in Indo group. However, these changes were reversed by Ole and Thym groups except the 500 mg/kg dose of Thym and the combination treatment groups. Similar trends were observed in the caspase-3 and TNF-α expression levels. These results demonstrated that enhanced inflammation, oxidant/antioxidant imbalance, and apoptotic activities were occurred in Indo, 500 mg/kg dose of Thym and the combination treatment groups while not in the other groups. The findings demonstrated the gastroprotective ability of Ole and low doses of Thym in gastric ulcer models.

Raging the War Against Inflammation With Natural Products

Over the last few decade Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are the drugs of choice for treating numerous inflammatory diseases including rheumatoid arthritis. The NSAIDs produces anti-inflammatory activity via inhibiting cyclooxygenase enzyme, responsible for the conversation of arachidonic acid to prostaglandins. Likewise, cyclooxegenase-2 inhibitors (COX-2) selectively inhibit the COX-2 enzyme and produces significant anti-inflammatory, analgesic, and anti-pyretic activity without producing COX-1 associated gastrointestinal and renal side effects. In last two decades numerous selective COX-2 inhibitors (COXIBs) have been developed and approved for various inflammatory conditions. However, data from clinical trials have suggested that the prolong use of COX-2 inhibitors are also associated with life threatening cardiovascular side effects including ischemic heart failure and myocardial infection. In these scenario secondary metabolites from natural product offers a great hope for the development of novel anti-inflammatory compounds. Although majority of the natural product based compounds exhibit more selectively toward COX-1. However, the data suggest that slight structural modification can be helpful in developing COX-2 selective secondary metabolites with comparative efficacy and limited side effects. This review is an effort to highlight the secondary metabolites from terrestrial and marine source with significant COX-2 and COX-2 mediated PGE2 inhibitory activity, since it is anticipated that isolates with ability to inhibit COX-2 mediated PGE2 production would be useful in suppressing the inflammation and its classical sign and symptoms. Moreover, this review has highlighted the potential lead compounds including berberine, kaurenoic acid, α-cyperone, curcumin, and zedoarondiol for further development with the help of structure-activity relationship (SAR) studies and their current status.

Comparative study of anti-VEGF Ranibizumab and Interleukin-6 receptor antagonist Tocilizumab in Adjuvant-induced Arthritis

Although the precise etiology of Rheumatoid arthritis (RA) remains obscure, heightened immune response is thought to play a vital role in provoking joint inflammation and bone erosion. This study aims at comparatively evaluating the effects of two monoclonal antibodies Ranibizumab (RANI) as anti-VEGF antibody and Tocilizumab (TCZ) as interleukin-6 receptor (IL-6R) antagonist, against adjuvant induced arthritis in rats. CFA-induced arthritic rats were treated for three consecutive weeks with Methotrexate (MTX), TCZ and RANI monotherapy. Clinical assessment of RA, bone erosion, inflammatory, angiogenic and apoptotic markers were determined to assess the anti-arthritic effect. Liver enzymes and histopathological examination of liver and spleen were assessed to evaluate the toxicity profile of the tested therapeutic agents. MTX, TCZ and RANI monotherapy significantly enhanced the anti-arthritic parameters in comparison with the Complete Freund's Adjuvant (CFA)-induced arthritic rats through significant reduction of ankle and paw swelling. Also, they significantly reduced inflammatory, angiogenic and apoptotic markers. Importantly, Ranibizumab showed better effect than the standard anti-rheumatic drugs Methotrexate (MTX) or Tocilizumab (TCZ) in bone protection and cartilage health; hence proves to be a promising new therapeutic agent for RA.

RETRACTED: Effects of Artesunate on chondrocyte proliferation, apoptosis and autophagy through the PI3K/AKT/mTOR signaling pathway in rat models with rheumatoid arthritis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figure 5D and 5F, which appear to have a similar phenotype as contained within another publication, as detailed here: https://pubpeer.com/publications/CD4DF7B6DCA28182EC6809846F3653; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. Concerns were also raised about the provenance of the flow cytometry data in Figure 7A. In addition, suspected duplications were detected in Western blots contained within Figure 5E and 5F. The journal requested the corresponding author comment on these concerns and provide raw data. The corresponding author communicated that the raw data was not available and some of the results were not repeatable and therefore not solid enough to support the conclusions. The authors requested retraction of this article. The Editor-in-Chief assessed this case and decided to retract the article.

Novel natural product therapeutics targeting both inflammation and cancer

Inflammation is recently recognized as one of the hallmarks of human cancer. Chronic inflammatory response plays a critical role in cancer development, progression, metastasis, and resistance to chemotherapy. Conversely, the oncogenic aberrations also generate an inflammatory microenvironment, enabling the development and progression of cancer. The molecular mechanisms of action that are responsible for inflammatory cancer and cancer-associated inflammation are not fully understood due to the complex crosstalk between oncogenic and pro-inflammatory genes. However, molecular mediators that regulate both inflammation and cancer, such as NF-κB and STAT have been considered as promising targets for preventing and treating these diseases. Recent works have further demonstrated an important role of oncogenes (e.g., NFAT1, MDM2) and tumor suppressor genes (e.g., p53) in cancer-related inflammation. Natural products that target these molecular mediators have shown anticancer and anti-inflammatory activities in preclinical and clinical studies. Sesquiterpenoids (STs), a class of novel plant-derived secondary metabolites have attracted great interest in recent years because of their diversity in chemical structures and pharmacological activities. At present, we and other investigators have found that dimeric sesquiterpenoids (DSTs) may exert enhanced activity and binding affinity to molecular targets due to the increased number of alkylating centers and improved conformational flexibility and lipophilicity. Here, we focus our discussion on the activities and mechanisms of action of STs and DSTs in treating inflammation and cancer as well as their structure-activity relationships.

In vivo anti-arthritic and anti-nociceptive effects of ethanol extract of Moringa oleifera leaves on complete Freund's adjuvant (CFA)-induced arthritis in rats

Background

The medicinal uses of plants are in many cases based exclusively on traditional knowledge without enough scientific evidences. Different parts of Moringa oleifera were traditionally used for the treatment of wide variety of ailments including arthritis and joints pain. The present study had been designed to evaluate the anti-arthritic and anti-nociceptive activities of ethanol extract of Moringa leaves, this being the most abundant plant part suitable for commercial mass production of botanical medicinal products.

Methods

Complete Freund's adjuvant (CFA)-induced arthritis in rats was used as disease model. CFA-induced inflammatory paw edema, body weight, arthritic index, X-ray radiography, hematological parameters, and walk track and locomotion analysis were all evaluated for the assessment of disease progression. In addition to that, anti-nociceptive activity was examined at different dose levels in both normal and arthritic-induced rats using Eddy's hot plate and tail flick thermal analgesia.

Results

The analysis of various arthritic assessment parameters used in this study revealed that Moringa extract has a considerable effect in preventing development or ameliorate arthritis disease severity. Moreover, the ethanol extract of Moringa leaves revealed significant anti-nociceptive activity at in both normal and CFA-induced arthritis rats in a dose-dependent manner.

Conclusion

Ethanol extract of Moringa leaves appears to be a really promising as analgesic and arthritis medication, but a larger and more detailed preclinical and clinical studies especially in human is highly recommended.

Chemoprevention by artesunate in a preclinical model of colorectal cancer involves down regulation of β-catenin, suppression of angiogenesis, cellular proliferation and induction of apoptosis

Use of anti-inflammatory drugs is well known to decrease the risk of colorectal cancer, one of the most common causes of cancer related mortality. In view of anti-inflammatory property of artesunate reported in various experimental models, the present study was carried out to evaluate its efficacy in rat model where colon carcinogenesis was induced by 1, 2 dimethylhydrazine (DMH). A time course study revealed that two injections of DMH given at an interval of one week resulted in appearance of multiple plaque lesions and aberrant crypt foci in the colon with a peak effect occurring at the end of 8 weeks. An efficacy study carried out with daily oral administration of artesunate (50 and 150 mg/kg) and aspirin (60 mg/kg) showed a marked reduction in pre-neoplastic changes with a significant decrease in the number of aberrant crypt foci, crypt multiplicity and restoration of histoarchitecture. Both the drugs down regulated β-catenin signaling, reduced the levels of angiogenic markers like VEGF, MMP-9 and inhibited cellular proliferation. The anti-cancer effect of these drugs was concomitant with the pro-apoptotic effect as revealed by increased DNA fragmentation, TUNEL positivity and Bax/Bcl₂ immunoreactivity. This is the first study to evaluate the inhibitory effect of artesunate on pre-neoplastic changes in colon where its chemopreventive effect was found to be comparable to that of aspirin. Our study strengthens the previous findings and shows that it has a preventive and therapeutic potential in the treatment of colon cancer.

Effects of Artesunate on the Expressions of Insulin-Like Growth Factor-1, Osteopontin and C-Telopeptides of Type II Collagen in a Rat Model of Osteoarthritis

Objective: The study aims to explore the effects of artesunate on insulin-like growth factor-1 (IGF-1), Osteopontin (OPN), and C-telopeptides of type II collagen (CTX-II) in serum, synovial fluid (SF), and cartilage tissues of rats with osteoarthritis (OA). Methods: OA models were established. Normal model, artesunate, and Viatril-S groups (20 rats respectively) were set. Enzyme-linked immunosorbent assay, IHC staining, and quantitative real-time polymerase chain reaction were conducted to calculate IGF-1, OPN, and CTX-II levels in serum, SF, and cartilage tissues of rats. The pathological changes in cartilage tissues were evaluated with Mankin score and Hematoxylin-Eosin staining. Results: Compared with the normal group, the model group showed increased IGF-1 level; decreased OPN, CTX-II levels in the serum and SF; and contrary results were seen in the cartilage tissues. A gradual ascending IGF-1 level and descending OPN and CTX-II levels existed in the serum and SF in the artesunate and Viatril-S groups after 2 weeks. The model group showed the most obvious pathological changes and highest Mankin score compared with the other groups. Higher IGF-1 level and lower OPN, CTX-II levels were exhibited in the cartilage tissue in the artesunate and Viatril-S groups but not in the model group. Conclusion: Artesunate and Viatril-S inhibit OA development by elevating IGF-1 level and reducing OPN and CTX-II levels.

Anti-inflammatory and anti-granuloma activity of Berberis aristata DC. in experimental models of inflammation

Objective:

Berberis aristata (Berberidaceae) is an important medicinal plant used in traditional system of medicine for the treatment of rheumatoid arthritis and other inflammatory disorders. The aim of the present study is to scientifically validate the traditional use of BA in the treatment of inflammatory disorders.

Materials and Methods:

Anti-inflammatory and anti-granuloma activity of BA hydroalcoholic extract (BAHE) were evaluated in experimental models, viz., carrageenan-induced paw edema, cotton pellet-induced granuloma formation, and complete Freund's adjuvant-induced stimulation of peritoneal macrophages in rats. Expression of inflammatory mediators, viz., tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, TNF-R1, and cyclooxygenase-2 (COX-2) was carried out in serum and peritoneal macrophages to derive the plausible mechanism of BAHE in activated peritoneal macrophages.

Results:

Pretreatment with BAHE produced a dose-dependent reduction (P < 0.01) in carrageenan-induced paw edema and cotton pellet-induced granuloma model. BAHE treatment produced significant (P < 0.01) reduction in serum inflammatory cytokine levels as compared to control. Protein expression of pro-inflammatory markers, IL-1β, IL-6, TNF-R1, and COX-2, was found to be reduced in stimulated macrophages whereas anti-inflammatory cytokine, IL-10, was upregulated in peritoneal macrophages.

Conclusion:

The result of the present study thus demonstrates the anti-inflammatory and anti-granuloma activity of BAHE which may be attributed to its inhibitory activity on macrophage-derived cytokine and mediators.

Artesunate Ameliorates Experimental Autoimmune Encephalomyelitis by Inhibiting Leukocyte Migration to the Central Nervous System

BACKGROUND AND AIMS

Experimental autoimmune encephalomyelitis (EAE) is T-cell-dependent disease of the central nervous system (CNS) of mice. This model resembles multiple sclerosis (MS) in many aspects. Therapies that focus in the modulation of the immune response and cellular infiltration in the CNS present best effects in the clinics. Artesunate (Art) is a semi-synthetic sesquiterpene derivative from artemisinin and has been shown to reduce the clinical signs of autoimmune disease models through mechanisms not yet understood. In this study, we aimed to evaluate whether administration of Art would ameliorate EAE.

METHODS AND RESULTS

C57BL6 mice were immunized with MOG35-55 peptide to induce EAE. At the same time, Art treatment started (3 mg/kg/day via i.p.) for five consecutive days. We found that Art treatment reduced the clinical signs of EAE and that correlated with a reduced infiltration of cells in the CNS. Disease amelioration did not correlate with immunomodulation as recall responses, leukocyte subpopulations, and gene expression analysis were similar among treated and untreated mice. Ultimately, further analysis provided data indicating that a possible mechanism of action for Art is dependent on the cellular migration to the CNS.

CONCLUSIONS

Artesunate reduces the severity of EAE by inhibiting migration of pathogenic T cells to the CNS.

Anti-inflammatory and immunoregulatory functions of artemisinin and its derivatives

Artemisinin and its derivatives are widely used in the world as the first-line antimalarial drug. Recently, growing evidences reveal that artemisinin and its derivatives also possess potent anti-inflammatory and immunoregulatory properties. Meanwhile, researchers around the world are still exploring the unknown bioactivities of artemisinin derivatives. In this review, we provide a comprehensive discussion on recent advances of artemisinin derivatives affecting inflammation and autoimmunity, the underlying molecular mechanisms, and also drug development of artemisinins beyond antimalarial functions.