Antioxidant activity and protective effect of suramin against oxidative stress in collagen induced arthritis

Anti-angiogenic and anti-oxidant effects of 2-NTI indole derivative vs. suramin in ex vivo, in vivo, and in vitro studies

Angiogenesis is an intricate pathway that involves the formation of new blood capillaries from old, functioning ones. Improper angiogenesis is a feature of numerous maladies, including malignancy and autoimmune disorders. Indole-related derivatives are believed to interfere with the mitotic spindle, inhibiting the multiplication, and invasion of cancerous human cells. 5-bromo-2-(5-(4-nitrophenyl)-4H-1,2,4-triazol-3-yl)-1H-indole (2-NTI) is one of such compounds with outstanding anti-angiogenic, and anti-proliferative properties. To evaluate 2-NTI's antiangiogenic and anti-oxidant activities and potential mechanisms of action in comparison with the standard agent, suramin. The rat aortic ring (RAR) and Chick chorioallantois membrane (CAM) assays were employed to determine antiangiogenic efficacy and dose response, while the DPPH assay estimated free radical scavenging activity. Besides, an MTT test was performed to evaluate antiproliferative activity in HUVECs; however, RT-PCR assessed the gene expression level of VEGF in HCT116 cells. 2-NTI displayed a significant and dose-dependent suppression of angiogenesis (83.04%) at 100 μg/mL concentration versus the negative controls in the RAR assay. 2-NTI also showed no toxicity in the HUVEC cell line, with an IC50 of 876.6 μg/mL, but it significantly reduced the formation of free radicals (IC50 of 135.2 µg/mL) and VEGF gene expression (at doses of 200 and 400 µg/mL) versus the negative controls and suramin. In CAM model, 2-NTI generated considerable blood vessel regression as compared to the negative control. 2-NTI possesses potent anti-angiogenic actions, which might be explained by its profound anti-proliferative and free radical detoxifying activities.

Protective effect of Tecoma stans (L.) Juss.ex Kunth in CFA-induced arthritic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tecoma stans (L.) Juss.ex Kunth (Bignoniaceae) is mainly found in tropical and subtropical regions of Africa and Asia. The leaves, flowers, roots, and bark are used to treat various aliments includes, skin infections, kidney problems, intestinal disorders, jaundice, toothaches, joint pain and repair cracked bones, antidotes for snake, scorpion, and rat bites.

AIM OF THE STUDY

The objective of the study is to assess the anti-arthritic properties of T. stans leaf using Complete Freund's adjuvant (CFA)-induced rat.

MATERIALS AND METHOD

The ethanol extract of T. stans leaf (ETSL) was subjected toGas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) analysis for the identification of potential bioactive. The anti-arthritic activity was carried out by administering CFA (0.1 ml) into the sub-plantar surface of the right hind paw. The experimental animals were treated with indomethacin (10 mg/kg) and ETSL (250, 500 mg/kg) once a day orally for fourteen days. The arthritic parameters and hematological and biochemical parameters were evaluated using standard kit reagents. The levels of pro-inflammatory cytokines and inflammatory mediators were measured in blood serum. Antioxidant parameters were assessed in homogenized liver and joint tissues. Radiological and histopathological analysis of joint was performed. A computational molecular docking investigation of the phytoconstituents was conducted against COX-2, IL-1β, IL-6, and TNF-α receptors.

RESULTS

The ETSL at 500 mg/kg demonstrated significant (p < 0.01) restoration of arthritic parameters, hematological and biochemical indices and oxidative stress in CFA-induced rats which was further supported by radiological histological examination. In addition, there was significant (p < 0.05) reduction observed in pro-inflammatory cytokines, inflammatory mediators and up-regulation of anti-inflammatory cytokines in the treated group. Verbascoside was found to exhibit better biding affinities -10.4, -7.4, -7 and -6.2 kcal/mol against COX-2, IL-1β, TNF-α, and IL-6 respectively, confirmed through in silico study.

CONCLUSIONS

The observed outcome suggests that ETSL at a dosage of 500 mg/kg demonstrated notable anti-arthritic effects by suppressing pro-inflammatory cytokines and oxidative stress biomarkers. This effect could potentially be attributed to the presence of bioactive verbascoside identified in the LC-MS analysis.

Novel peptide inhibitor of human tumor necrosis factor-α has antiarthritic activity

The inhibition of tumor necrosis factor (TNF)-α trimer formation renders it inactive for binding to its receptors, thus mitigating the vicious cycle of inflammation. We designed a peptide (PIYLGGVFQ) that simulates a sequence strand of human TNFα monomer using a series of in silico methods, such as active site finding (Acsite), protein-protein interaction (PPI), docking studies (GOLD and Flex-X) followed by molecular dynamics (MD) simulation studies. The MD studies confirmed the intermolecular interaction of the peptide with the TNFα. Fluorescence-activated cell sorting and fluorescence microscopy revealed that the peptide effectively inhibited the binding of TNF to the cell surface receptors. The cell culture assays showed that the peptide significantly inhibited the TNFα-mediated cell death. In addition, the nuclear translocation of the nuclear factor kappa B (NFκB) was significantly suppressed in the peptide-treated A549 cells, as observed in immunofluorescence and gel mobility-shift assays. Furthermore, the peptide protected against joint damage in the collagen-induced arthritis (CIA) mouse model, as revealed in the micro focal-CT scans. In conclusion, this TNFα antagonist would be helpful for the prevention and repair of inflammatory bone destruction and subsequent loss in the mouse model of CIA as well as human rheumatoid arthritis (RA) patients. This calls upon further clinical investigation to utilize its potential effect as an antiarthritic drug.

The bumpy road of purinergic inhibitors to clinical application in immune-mediated diseases

ABSTRACT

Purinergic signaling plays important roles throughout the body in the regulation of organ functions during and following the disruption of homeostasis. This is also reflected by the widespread expression of two families of purinergic receptors (P1 and P2) with numerous subtypes. In the last few decades, there has been increasing evidence that purinergic signaling plays an important role in the regulation of immune functions. Mainly, signals mediated by P2 receptors have been shown to contribute to immune system-mediated pathologies. Thus, interference with P2 receptors may be a promising strategy for the modulation of immune responses. Although only a few clinical studies have been conducted in isolated entities with limited success, preclinical work suggests that the use of P2 receptor inhibitors may bear some promise in various autoimmune diseases. Despite the association of P2 receptors with several disorders from this field, the use of P2 receptor antagonists in clinical therapy is still very scarce. In this narrative review, we briefly review the involvement of the purinergic system in immunological responses and clinical studies on the effect of purinergic inhibition on autoimmune processes. We then open the aperture a bit and show some preclinical studies demonstrating a potential effect of purinergic blockade on autoimmune events. Using suramin, a non-specific purinergic inhibitor, as an example, we further show that off-target effects could be responsible for observed effects in immunological settings, which may have interesting implications. Overall, we believe that it is worthwhile to further investigate this hitherto underexplored area.

RNA-seq revealed the anti-pyroptotic effect of suramin by suppressing NLRP3/caspase-1/GSDMD pathway in LPS-induced MH-S alveolar macrophages

BACKGROUND

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), acting as one common sepsis-associated organ injury, induces uncontrolled and self-amplifies pulmonary inflammation. Given the lack of clinically effective approaches, the mortality rate of it still remains high. Suramin(SUR), as an antiparasitic drug initially, was found to ameliorate sepsis associated ALI in our previous work. However, the underlying mechanism of its protective effects has not been clarified. Pyroptosis, categorized as an inflammatory form of programmed cell death, could aggravate lung inflammatory responses via inducing alveolar macrophages (AM) pyroptosis.

METHODS

MH-S AM cell line was stimulated with or without lipopolysaccharide (LPS) or suramin, and the differential expression genes (DEGs) were excavated using RNA sequencing (RNA-seq). To identify the regulatory roles of these genes, pyroptosis-related genes (PRGs), GO/KEGG and GSEA analysis were conducted. We also performed WB, qRTPCR and ELISA to validate the RNA-seq results and further expound the protective effect of suramin.

RESULTS

624 DEGs were identified between control (CON) and lipopolysaccharide (LPS) groups, and enrichment analysis of these genes revealed significantly enriched pathways that related to immune system and signal transduction. Meanwhile, 500 DEGs were identified in LPS/SUR+LPS group. In addition to the pathways mentioned above, IL-17 pathway and C-type lectin receptor signaling pathway were also enriched. All 6 pathways were connected with pyroptosis. Concurrently, the "DESeq2" R package was used to identify differentially expressed PRGs. Nod1, Nod2, interleukin (IL)-1b, IL-6, tumor necrosis factor (TNF), NLRP3 were upregulated under LPS stimulation. Then, in SUR+LPS group, Nod2, IL-6, IL-1b, NLRP3 were downregulated. The validation results of WB, qRT-PCR, and ELISA showed: the protein and mRNA expression levels of NLRP3, caspase-1, GSDMD and the concentrations of IL-1b, IL-18 were decreased when treated with suramin and LPS.

CONCLUSION

Suramin could inhibit NLRP3/caspase-1/GSDMD canonical pyroptosis pathway in LPS-induced MH-S alveolar macrophages.

Suramin ameliorates osteoarthritis by acting on the Nrf2/HO-1 and NF-κB signaling pathways in chondrocytes and promoting M2 polarization in macrophages

Osteoarthritis (OA)-the most prevalent of arthritis diseases-is a complicated pathogenesis caused by cartilage degeneration and synovial inflammation. Suramin has been reported to enhance chondrogenic differentiation. However, the therapeutic effect of suramin on OA-induced cartilage destruction has remained unclear. Suramin is an anti-parasitic drug that has potent anti-purinergic properties. This study investigated the protective effects and underlying mechanisms of suramin on articular cartilage degradation using an in vitro study and mice model with post-traumatic OA. We found that suramin markedly suppressed the IL-1β increased expression of matrix destruction proteases-such as ADAMT4, ADAMTS5, MMP3, MMP13, and inflammatory mediators-including the iNOS, COX2, TNFα, and IL-1β; while greatly enhancing the synthesis of cartilage anabolic factors-such as COL2A1, Aggrecan and SOX9 in IL-1β-induced porcine chondrocytes. In vivo experiments showed that intra-articular injection of suramin ameliorated cartilage degeneration and inhibited synovial inflammation in an anterior cruciate ligament transection (ACLT)-induced OA mouse model. In mechanistic studies, we found that exogenous supplementation of suramin can activate Nrf2, and accordingly inhibit the nuclear factor kappa-light-chain-enhancer of activated B cells (NF- κB) and mitogen-activated protein kinase (MAPK) pathways, thereby alleviating the inflammation and ECM degeneration of chondrocytes stimulated by IL-1β. In addition, suramin also repolarized M1 macrophages to the M2 phenotype, further reducing the apoptosis of chondrocytes. Collectively, the results of the study suggests that suramin is a potential drugs which could serve as a facilitating drug for the application of OA therapy toward clinical treatment.

Immunostimulants for shrimp aquaculture: paving pathway towards shrimp sustainability

At present, food security is a matter of debate of global magnitude and fulfilling the feeding requirement of > 8 billion human populations by 2030 is one of the major concerns of the globe. Aquaculture plays a significant role to meet the global food requirement. Shrimp species such as Litopenaeus vannamei, Penaeus monodon, and Macrobrachium rosenbergii are among the most popular food commodities worldwide. As per Global Outlook for Aquaculture Leadership survey, disease outbreaks have been a matter of concern from the past many decades regarding the shrimp aquaculture production. Among the past disease outbreaks, white spot disease caused by the white spot syndrome virus is considered to be one of the most devastating ones that caused colossal losses to the shrimp industry. Since the virus is highly contagious, it spreads gregariously among the shrimp population; hence, practicing proper sanitization practices is crucial in order to have disease-free shrimps. Additionally, in order to control the disease, antibiotics were used that further leads to bioaccumulation and biomagnification of antibiotics in several food webs. The bioaccumulation of the toxic residues in the food webs further adversely affected human too. Recently, immunostimulants/antivirals were used as an alternative to antibiotics. They were found to enhance the immune system of shrimps in eco-friendly manner. In context to this, the present paper presents a critical review on the immunostimulants available from plants, animals, and chemicals against WSSV in shrimps. Looking into this scenario, maintaining proper sanitation procedures in conjunction with the employment of immunostimulants may be a viable approach for preserving shrimp aquaculture across the globe.

Effects of Stromal Cell Conditioned Medium and Antipurinergic Treatment on Macrophage Phenotype

The immunomodulatory capacity of the human mesenchymal stromal cell (MSC) secretome has been a critical driver for the development of cell-free MSC products, such as conditioned medium (CM), for regenerative medicine applications. This is particularly true as cell-free MSC products present several advantages over direct autologous or allogeneic MSC delivery with respect to safety, manufacturability, and defined potency. Recently, significant effort has been placed into creating novel MSC CM formulations with an immunomodulatory capacity tailored for specific regenerative contexts. For instance, the immunoregulatory nature of MSC CM has previously been tuned through a number of cytokine-priming strategies. Herein, we propose an alternate method to tailor the immunomodulatory "phenotype" of cytokine-primed MSC CM through coupling with the pharmacological agent, suramin. Suramin interferes with the signaling of purines including extracellular adenosine triphosphate (ATP), which plays a critical role in the activation of the innate immune system after injury. Toward this end, human THP-1-derived macrophages were activated to a proinflammatory phenotype and treated with (1) unprimed/native MSC CM, (2) interferon-γ/tumor necrosis factor α-primed MSC CM (primed CM), (3) suramin alone, or (4) primed MSC CM and suramin (primed CM/suramin). Markers of key macrophage functions-cytokine secretion, autophagy, oxidative stress modulation, and activation/migration-were assessed. Consistent with previous literature, primed CM elevated macrophage secretion of several proinflammatory and pleiotropic cytokines relative to native CM; whereas addition of suramin imparted consistent shifts in terms of TNFα (↓), interleukin-10 (↓), and hepatocyte growth factor (↑) irrespective of CM. In addition, both primed CM and suramin, individually and combined, increased reactive oxygen species production relative to native CM, and addition of suramin to primed CM shifted levels of CX3CL1, a factor involved in ATP-associated macrophage regulation. Varimax rotation assessment of the secreted cytokine profiles confirmed that primed CM/suramin resulted in a THP-1 phenotypic shift away from the lipopolysaccharide-activated proinflammatory state that was distinct from that of primed CM or native CM alone. This altered primed CM/suramin-associated phenotype may prove beneficial for healing in certain regenerative contexts. These results may inform future work coupling antipurinergic treatments with MSC-derived therapies in regenerative medicine applications.

Troxerutin-Mediated Complement Pathway Inhibition is a Disease-Modifying Treatment for Inflammatory Arthritis

Troxerutin (TXR) is a phytochemical reported to possess anti-inflammatory and hepatoprotective effects. In this study, we aimed to exploit the antiarthritic properties of TXR using an adjuvant-induced arthritic (AIA) rat model. AIA-induced rats showed the highest arthritis score at the disease onset and by oral administration of TXR (50, 100, and 200 mg/kg body weight), reduced to basal level in a dose-dependent manner. Isobaric tags for relative and absolute quantitative (iTRAQ) proteomics tool were employed to identify deregulated joint homogenate proteins in AIA and TXR-treated rats to decipher the probable mechanism of TXR action in arthritis. iTRAQ analysis identified a set of 434 proteins with 65 deregulated proteins (log₂ case/control≥1.5) in AIA. Expressions of a set of important proteins (AAT, T-kininogen, vimentin, desmin, and nucleophosmin) that could classify AIA from the healthy ones were validated using Western blot analysis. The Western blot data corroborated proteomics findings. In silico protein–protein interaction study of tissue-proteome revealed that complement component 9 (C9), the major building blocks of the membrane attack complex (MAC) responsible for sterile inflammation, get perturbed in AIA. Our dosimetry study suggests that a TXR dose of 200 mg/kg body weight for 15 days is sufficient to bring the arthritis score to basal levels in AIA rats. We have shown the importance of TXR as an antiarthritic agent in the AIA model and after additional investigation, its arthritic ameliorating properties could be exploited for clinical usability.

Purinergic signaling is essential for full Psickle activation by hypoxia and by normoxic acid pH in mature human sickle red cells and in vitro-differentiated cultured human sickle reticulocytes

Paracrine ATP release by erythrocytes has been shown to regulate endothelial cell function via purinergic signaling, and this erythoid-endothelial signaling network is pathologically dysregulated in sickle cell disease. We tested the role of extracellular ATP-mediated purinergic signaling in the activation of Psickle, the mechanosensitive Ca²⁺-permeable cation channel of human sickle erythrocytes (SS RBC). Psickle activation increases intracellular [Ca²⁺] to stimulate activity of the RBC Gardos channel, KCNN4/KCa3.1, leading to cell shrinkage and accelerated deoxygenation-activated sickling.We found that hypoxic activation of Psickle recorded by cell-attached patch clamp in SS RBC is inhibited by extracellular apyrase, which hydrolyzes extracellular ATP. Hypoxic activation of Psickle was also inhibited by the pannexin-1 inhibitor, probenecid, and by the P2 antagonist, suramin. A Psickle-like activity was also activated in normoxic SS RBC (but not in control red cells) by bath pH 6.0. Acid-activated Psickle-like activity was similarly blocked by apyrase, probenecid, and suramin, as well as by the Psickle inhibitor, Grammastola spatulata mechanotoxin-4 (GsMTx-4).In vitro-differentiated cultured human sickle reticulocytes (SS cRBC), but not control cultured reticulocytes, also exhibited hypoxia-activated Psickle activity that was abrogated by GsMTx-4. Psickle-like activity in SS cRBC was similarly elicited by normoxic exposure to acid pH, and this acid-stimulated activity was nearly completely blocked by apyrase, probenecid, and suramin, as well as by GsMTx-4.Thus, hypoxia-activated and normoxic acid-activated cation channel activities are expressed in both SS RBC and SS cRBC, and both types of activation appear to be mediated or greatly amplified by autocrine or paracrine purinergic signaling.

Phytomedicine in Disease Management: In-Silico Analysis of the Binding Affinity of Artesunate and Azadirachtin for Malaria Treatment

In the rural communities of sub-Saharan African (sSA) countries, malaria is being managed using phytocompounds. Artesunate is reported to inhibit Gephyrin E, a central, multi-domain scaffolding protein of inhibitory post-synapses. Neem plant and its metabolites like azadirachtin are being indicated for management of malaria by traditional healers. The present study was aimed to cheminformatically analyse the binding potential of artesunate and azadirachtin with various reactive moieties of Gephyrin E, to reduce malaria scourge. With molecular dynamics (MD), binding free energy estimation and binding affinity of artesunate and azadirachtin to Gephyrin E was done. GRIP docking was done to study the interactions of these test ligands with Gephyrin E (6FGC). MD simulation gave insights to structural changes upon binding of artesunate and azadirachtin in the ligand-binding pocket of Gephyrin E. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) were calculated. From the estimation, azadirachtin had a total binding energy of -36.97 kcal/mol; artesunate had a binding energy of -35.73 kcal/mol. The GRIP docking results provided a clearer evidence that artesunate has comparatively better binding affinity to Gephyrin E than azadirachtin, and the critical binding sites (in activity order) were cavity 3, 2, 8, and 6 for artesunate while for azadirachtin, it was cavity 6, 3, 8, and 2. The GRIP docking provided detailed interactions at the atomic levels, providing evidence; both compounds have chances to overcome the drug resistance problem, albeit higher for artesunate. Our findings added another piece of evidence that azadirachtin may be effective as an anti-malarial agent. The results herein may provide impetus for more studies into bioactive components of plant origin towards the effective management of malaria disease phenotype.

Suramin attenuates intervertebral disc degeneration by inhibiting NF-κB signalling pathway

Aims

Interleukin (IL)-1β is one of the major pathogenic regulators during the pathological development of intervertebral disc degeneration (IDD). However, effective treatment options for IDD are limited. Suramin is used to treat African sleeping sickness. This study aimed to investigate the pharmacological effects of suramin on mitigating IDD and to characterize the underlying mechanism.

Methods

Porcine nucleus pulposus (NP) cells were treated with vehicle, 10 ng/ml IL-1β, 10 μM suramin, or 10 μM suramin plus IL-1β. The expression levels of catabolic and anabolic proteins, proinflammatory cytokines, mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB-related signalling molecules were assessed by Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence analysis. Flow cytometry was applied to detect apoptotic cells. The ex vivo effects of suramin were examined using IDD organ culture and differentiation was analyzed by Safranin O-Fast green and Alcian blue staining.

Results

Suramin inhibited IL-1β-induced apoptosis, downregulated matrix metalloproteinase (MMP)-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, and ADAMTS-5, and upregulated collagen 2A (Col2a1) and aggrecan in IL-1β-treated NP cells. IL-1β-induced inflammation, assessed by IL-1β, IL-8, and tumour necrosis factor α (TNF-α) upregulation, was alleviated by suramin treatment. Suramin suppressed IL-1β-mediated proteoglycan depletion and the induction of MMP-3, ADAMTS-4, and pro-inflammatory gene expression in ex vivo experiments.

Conclusion

Suramin administration represents a novel and effectively therapeutic approach, which could potentially alleviate IDD by reducing extracellular matrix (ECM) deposition and inhibiting apoptosis and inflammatory responses in the NP cells.

Cite this article: Bone Joint Res 2021;10(8):498–513.

Effect of suramin on urinary excretion of diabetes-induced glomerular and tubular injury parameters in rats

Diabetes mellitus causes changes in metabolism of extracellular nucleotides acting through P2 receptors (P2Rs). This affects renal function and may lead to glomerular and tubular disturbances. We measured urinary excretion of nucleotides (ATP, ADP, AMP, UTP, UDP, UMP) in streptozotocin-induced diabetic rats (65 mg/kg, i.p., day 0) and the effects of P2Rs' blockade by suramin (10 mg/kg, i.p., days +7, +14) on glomerular P2×7R expression and urinary excretion of glomerular (albumin, nephrin) and tubular (KIM-1, NGAL) injury markers, electrolytes, and oxidative stress markers (TBARS, 8-OHdG). Concentrations of nucleotides, specific proteins, electrolytes, and oxidative stress markers in 24-h urine samples collected in metabolic cages at days -1, +6 and +20 were measured using ion-paired reversed-phase HPLC, immunoenzymatic and fluorometric methods, and flame photometry, respectively. Expression of KIM-1 and P2×7R was examined by immunohistochemistry or immunoblotting. Diabetes was associated with increased urinary excretion of ATP, ADP, UTP, UDP and glomerular P2×7R expression. Suramin attenuated P2×7R expression but did not affect urinary excretion of nucleotides. Urinary excretion of albumin, nephrin, NGAL, and 8-OHdG were increased in diabetic rats and were not affected by suramin. TBARS was higher in diabetic rats and suramin attenuated the excretion dynamics in this group. KIM-1 excretion was higher in diabetic rats and suramin further increased excretion of KIM-1 in both diabetic and non-diabetic rats. Furthermore, suramin attenuated the diabetes-induced natriuresis and kaliuresis. It is possible that suramin affects both glomerular and tubular functions in diabetic rats.

Zingiber roseum Rosc. rhizome: A rich source of hepatoprotective polyphenols

Zingiber roseum is native to Bangladesh and widely used in folk medicine. This present study was designed to assess the ameliorative potential of Zingiber roseum rhizome extract in carbon tetrachloride (CCl₄) induced hepatotoxicity in mice model. Seven phenolic compounds were identified and quantified by HPLC analysis in the plant extract, including quercetin, myricetin, catechin hydrate, trans-ferulic acid, trans-cinnamic acid, (-) epicatechin, and rosmarinic acid. Hepatotoxicity was induced by administrating a single intraperitoneal injection of CCl₄ (10 mL/kg) on 7th day of treatment. The results revealed that plant extract at all doses (100, 200 and 400 mg/kg) significantly reduced (p < 0.05) the elevated serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) concentrations, and these effects were comparable to that of standard drug silymarin. Histopathological examination also revealed the evidence of recovery from CCL₄ induced cellular damage when pretreated with Z. roseum rhizome extract. The in-vivo hepatoprotective effects were further investigated by the in-silico study of the aforementioned compounds with liver-protective enzymes such as superoxide dismutase (SOD), peroxiredoxin, and catalase. The strong binding affinities (ranging from -7.3359 to -9.111 KCal/mol) between the phenolic compounds (except trans-cinnamic acid) and oxidative stress enzymes inhibit ROS production during metabolism. The compounds were also found non-toxic in computational prediction, and a series of biological activities like antioxidant, anticarcinogen, cardio-protectant, hepato-protectant have been detected.

A novel antiviral coumarin derivative as a potential agent against WSSV infection in shrimp seedling culture

White spot syndrome virus (WSSV), a double-stranded DNA virus that infects crustaceans, is the most serious viral pathogen affecting shrimp farming worldwide. To reduce the economic losses caused by WSSV, we screened a novel coumarin derivative from a small molecule drug library, N-(4-((4-(((2-oxo-2H-chromen-7-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl)sulfonyl)phenyl)acetamide (N2905), to evaluate its anti-WSSV effects in vivo. We determined that compound N2905, up to a concentration of 20 mg/L, significantly decreased the number of WSSV copies in Litopenaeus vannamei post-larvae, with a maximum inhibitory rate of > 90 %, and increased the survival rate of WSSV-infected post-larvae. Pre-treatment and post-treatment assays indicated that N2905 could treat, but not prevent, WSSV infections. When WSSV was preincubated with N2905 for 1-4 h, the incidence of viral infections was significantly reduced and survival time of post-larvae extended to 120 h. A stability study of N2905 provided a reference for its practical use. Considering the antiviral stability of N2905 in culture water within 2 d, continuous N2905 exchange was performed, showing a significant decrease in viral load at 120 h post-infection (hpi) and a 55 % increase in survival of WSSV-infected post-larvae. Overall, our study demonstrated the potential of N2905 as an antiviral agent.

Hydrogen Peroxide Inducible JAK3 Covalent Inhibitor: Prodrug for the Treatment of RA with Enhanced Safety Profile

Selective inhibition of Janus kinases (JAKs) is an arising strategy in drug discovery. Covalent inhibitors targeting a unique cysteine in JAK3 exhibit ultraselectivity among JAK family members. However, safety and tissue specific concerns still remain. A prodrug of a known JAK3 covalent inhibitor sensitive to H₂O₂ was designed and synthesized and its therapeutic effect was evaluated in the CIA (collagen-induced arthritis) mice model of RA (rheumatoid arthritis). The prodrug strategy relied on the introduction of a hydrogen peroxide-sensitive borate trigger group to avoid random covalent binding to thiol functionalities in biomacromolecules. The results show that the prodrug can be activated and released under pathophysiological concentration of H₂O₂. In addition, the prodrug demonstrated stability to the physiological environment. In comparison to the parent compound, the prodrug showed a similar therapeutic effect in the CIA model but notably exhibited lower toxicity and a larger therapeutic window.

Designing of Chitosan Derivatives Nanoparticles with Antiangiogenic Effect for Cancer Therapy

Angiogenesis is a physiological process involving the growth of new blood vessels, which provides oxygen and required nutrients for the development of various pathological conditions. In a tumor microenvironment, this process upregulates the growth and proliferation of tumor cells, thus any stage of angiogenesis can be a potential target for cancer therapies. In the present study, chitosan and his derivatives have been used to design novel polymer-based nanoparticles. The therapeutic potential of these newly designed nanoparticles has been evaluated. The antioxidant and MTT assays were performed to know the antioxidant properties and their biocompatibility. The in vivo antiangiogenic properties of the nanoparticles were evaluated by using a chick Chorioallantoic Membrane (CAM) model. The obtained results demonstrate that chitosan derivatives-based nanostructures strongly enhance the therapeutic effect compared to chitosan alone, which also correlates with antitumor activity, demonstrated by the in vitro MTT assay on human epithelial cervical Hep-2 tumor cells. This study opens up new direction for the use of the chitosan derivatives-based nanoparticles for designing of antiangiogenic nanostructured materials, for future cancer therapy.

A closer look into NADPH oxidase inhibitors: Validation and insight into their mechanism of action

NADPH-oxidases (NOXs) purposefully produce reactive-oxygen-species (ROS) and are found in most kingdoms of life. The seven human NOXs are each characterized by a specific expression profile and a fine regulation to spatio-temporally tune ROS concentration in cells and tissues. One of the best known roles for NOXs is in host protection against pathogens but ROS themselves are important second messengers involved in tissue regeneration and the modulation of pathways that induce and sustain cell proliferation. As such, NOXs are attractive pharmacological targets in immunomodulation, fibrosis and cancer. We have studied an extensive number of available NOX inhibitors, with the specific aim to identify bona fide ligands versus ROS-scavenging molecules. Accordingly, we have established a comprehensive platform of biochemical and biophysical assays. Most of the investigated small molecules revealed ROS-scavenging and/or assay-interfering properties to various degrees. A few compounds, however, were also demonstrated to directly engage one or more NOX enzymes. Diphenylene iodonium was found to react with the NOXs' flavin and heme prosthetic groups to form stable adducts. We also discovered that two compounds, VAS2870 and VAS3947, inhibit NOXs through the covalent alkylation of a cysteine residue. Importantly, the amino acid involved in covalent binding was found to reside in the dehydrogenase domain, where the nicotinamide ring of NADPH is bound. This work can serve as a springboard to guide further development of bona fide ligands with either agonistic or antagonistic properties toward NOXs.

Regulation of CD39 expression in ATP-P2Y2R-mediated alcoholic liver steatosis and inflammation

Inflammation plays a central role in the progression of alcoholic liver disease. ATP-P2Y2R signaling and CD39 play an important role in various diseases, but little is known about their role in alcoholic liver steatosis and inflammation. As a transmembrane hydrolase, CD39 hydrolyzes ATP, while the mutual regulation of CD39 and ATP-P2Y2R in alcoholic steatohepatitis is poorly understood. Here, we found that the expression of ATP, P2Y2R, and CD39 is increased significantly both in the liver of alcohol-fed mice and alcohol-induced RAW264.7 cell lines. In this study, C57BL/6 mice were intrapretationally injected with P2Y2R inhibitor suramin from day 4 until day 10 during the induction of a chronic/binge drinking model. Pharmacological blockade of P2Y2R largely prevents liver damage, lipid accumulation, and inflammation, with concomitant down-expression of CD39 in liver. We found that the inhibition of P2Y2R in vitro reduces inflammation via down-expression of interleukin 6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α), and the expression of CD39 was reduced, whereas the activation of P2Y2R showed an opposite effect. Silencing of CD39 promoted the expression of ATP and P2Y2R. These results indicate that CD39 attenuates alcohol-induced steatohepatitis by scavenging extracellular ATP to indirectly regulate the expression of P2Y2R. Interestingly, P2Y2R paradoxically boosts CD39 activity. Thus, blockade of the extracellular ATP-P2Y2R signalling represents a potential therapeutic approach against alcoholic liver disease, and CD39 is a potential therapeutic target.

Evaluating the impact of suramin additive on CHO cells producing Fc-fusion protein

OBJECTIVE

To examine the effects of suramin in CHO cell cultures in terms of the cell culture performance and quality of the Fc-fusion protein.

RESULTS

Suramin had positive effects on the CHO cell cultures. The addition of suramin caused an increase in the viable cell density, cell viability, and titer of the Fc-fusion protein. Moreover, suramin had no impact on protein aggregation and enhanced the sialic acid contents of Fc-fusion protein by 1.18-fold. The enhanced sialylation was not caused by the increased nucleotide sugar level but by the inhibition of sialidase activity. The results showed that suramin inhibited apoptosis and had positive impacts on the productivity and quality of Fc-fusion protein.

CONCLUSION

The addition of suramin increased the production of Fc-fusion protein and enhanced sialylation when added as a supplement to the media component in CHO cell cultures. This study suggested that suramin could be a beneficial additive during the biological production in terms of the productivity and quality of Fc-fusion protein.

The anti-parasitic drug suramin potently inhibits formation of seminal amyloid fibrils and their interaction with HIV-1

Seminal amyloid fibrils are made up of naturally occurring peptide fragments and are key targets for the development of combination microbicides or antiviral drugs. Previously, we reported that the polysulfonic compound ADS-J1 is a potential candidate microbicide that not only inhibits HIV-1 entry, but also seminal fibrils. However, the carcinogenic azo moieties in ADS-J1 preclude its clinical application. Here, we screened several ADS-J1-like analogs and found that the antiparasitic drug suramin most potently inhibited seminal amyloid fibrils. Using various biochemical methods, including Congo red staining, CD analysis, transmission EM, viral infection assays, surface plasmon resonance imaging, and molecular dynamics simulations, we investigated suramin's inhibitory effects and its putative mechanism of action. We found that by forming a multivalent interaction, suramin binds to proteolytic peptides and mature fibrils, thereby inhibiting seminal fibril formation and blocking fibril-mediated enhancement of viral infection. Of note, suramin exhibited potent anti-HIV activities, and combining suramin with several antiretroviral drugs produced synergistic effects against HIV-1 in semen. Suramin also displayed a good safety profile for vaginal application. Moreover, suramin inhibited the semen-derived enhancer of viral infection (SEVI)/semen-mediated enhancement of HIV-1 transcytosis through genital epithelial cells and the subsequent infection of target cells. Collectively, suramin has great potential for further development as a combination microbicide to reduce the spread of the AIDS pandemic by targeting both viral and host factors involved in HIV-1 sexual transmission.

Whortleberry protects kidney against the cisplatin-induced nephrotoxicity: an experimental study

Purpose: This study investigated the antioxidant effects of whortleberry against cisplatin-induced nephrotoxicity in rats.

Material and methods: This study included 48 female Sprague–Dawley rats weighing 263.68 ± 8.29 g. The rats were divided into the following six groups, with eight rats in each group: control, ethanol control, whortleberry control, cisplatin control, 16 mg/kg cisplatin +100 mg/kg whortleberry, and 16 mg/kg cisplatin +200 mg/kg whortleberry groups. Biochemical analysis was performed by measuring total oxidant status and total antioxidant status, histopathological analysis was performed by calculating proximal and distal tubule areas (μm²), and immunohistochemical analysis was performed by determining anti-Caspase-3 immunostaining. Differences among the groups were examined using one-way analysis of variance, and p < .05 was considered statistically significant.

Results: Cisplatin treatment decreased the total antioxidant status and increased the total oxidant status and Caspase-3 level. Moreover, it resulted in the dilatation, vacuolization and loss of tubular epithelial cells; and glomerular degeneration and edema in the kidney tissues (p < .05). Treatment with 100 and 200 mg whortleberries increased the total antioxidant status; decreased the total oxidant status and Caspase-3 level and ameliorated distal and proximal tubule degeneration, glomerular degeneration and edema in the kidney tissues (p < .05).

Conclusions: Our results indicate that the antioxidant effects of the whortleberry decrease cisplatin-associated nephrotoxicity.

Synthesis and Evaluation of Hydrogen Peroxide Sensitive Prodrugs of Methotrexate and Aminopterin for the Treatment of Rheumatoid Arthritis

A series of novel hydrogen peroxide sensitive prodrugs of methotrexate (MTX) and aminopterin (AMT) were synthesized and evaluated for therapeutic efficacy in mice with collagen induced arthritis (CIA) as a model of chronic rheumatoid arthritis (RA). The prodrug strategy selected is based on ROS-labile 4-methylphenylboronic acid promoieties linked to the drugs via a carbamate linkage or a direct C-N bond. Activation under pathophysiological concentrations of H₂O₂ proved to be effective, and prodrug candidates were selected in agreement with relevant in vitro physicochemical and pharmacokinetic assays. Selected candidates showed moderate to good solubility, high chemical and enzymatic stability, and therapeutic efficacy comparable to the parent drugs in the CIA model. Importantly, the prodrugs displayed the expected safer toxicity profile and increased therapeutic window compared to MTX and AMT while maintaining a comparable therapeutic efficacy, which is highly encouraging for future use in RA patients.

Antioxidative and anti-proliferative potential of Curculigo orchioides Gaertn in oxidative stress induced cytotoxicity: In vitro, ex vivo and in silico studies

Plant phytoconstituents have been a valuable source of clinically important anticancer agents. Antioxidant and anticancerous activity of plant Curculigo orchioides Gaertn were explored In vitro antioxidant activity, antioxidant enzyme activity of oxidatively stressed tissue, and cell culture studies on human cancer cell lines HepG2, HeLa and MCF-7 were carried out. Active plant fractions were subjected to GC-MS analysis and compounds selected on the basis of their abundance were screened in silico with the help of Auto Dock 4.2 tools with pre-selected antioxidant enzymes. Curculigo orchioides Gaertn plant fractions exhibited significant antioxidant activities by virtue of scavenging of free radicals having IC₅₀ value of ethylacetate fraction (EA) for DPPH radical scavenging assay to be 52.93 ± 0.66 μg/ml. Further, antioxidant enzyme defense of mammalian tissue when treated with plant fractions revealed that enzyme concentrations were refurbished which were increased during oxidative stress. MTT assay on cell lines HepG2, HeLa and MCF-7 presented IC₅₀ values of ethylacetate (EA) fraction as 171.23 ± 2.1 μg/ml, 144.80 ± 1.08 μg/ml and 153.51 μg/ml and aqueous ethylacetate (AEA) fraction as 133.44 ± 1.1 μg/ml, 136.50 ± 0.8 μg/ml and 145.09 μg/ml respectively. Further EA and AEA plant fractions down regulated the levels of antiapoptotic Bcl-2 expression and upregulated the expression of apoptotic proteins caspase-3 and caspase-8 through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

KEY MESSAGE

Key findings explained that fractions of Curculigo orchioides Gaertn inhibited oxidative stress by increasing the antioxidant enzyme content and have anticancerous potential on cancer cell lines HepG2, HeLa and MCF-7.