scholarly journals Arginine-Based Inhibitors of Nitric Oxide Synthase: Therapeutic Potential and Challenges

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Jan Víteček ◽  
Antonín Lojek ◽  
Giuseppe Valacchi ◽  
Lukáš Kubala

In the past three decades, nitric oxide has been well established as an important bioactive molecule implicated in regulation of cardiovascular, nervous, and immune systems. Therefore, it is not surprising that much effort has been made to find specific inhibitors of nitric oxide synthases (NOS), the enzymes responsible for production of nitric oxide. Among the many NOS inhibitors developed to date, inhibitors based on derivatives and analogues of arginine are of special interest, as this category includes a relatively high number of compounds with good potential for experimental as well as clinical application. Though this group of inhibitors covers early nonspecific compounds, modern drug design strategies such as biochemical screening and computer-aided drug design have provided NOS-isoform-specific inhibitors. With an emphasis on major advances in this field, a comprehensive list of inhibitors based on their structural characteristics is discussed in this paper. We provide a summary of their biochemical properties as well as their observed effects bothin vitroandin vivo. Furthermore, we focus in particular on their pharmacology and use in recent clinical studies. The potential of newly designed specific NOS inhibitors developed by means of modern drug development strategies is highlighted.

2007 ◽  
Vol 293 (4) ◽  
pp. R1608-R1618 ◽  
Author(s):  
Bin Geng ◽  
Yuying Cui ◽  
Jing Zhao ◽  
Fang Yu ◽  
Yi Zhu ◽  
...  

The aim of the present study was to investigate the effect of hydrogen sulfide (H2S) signaling by nitric oxide (NO) in isolated rat aortas and cultured human umbilical vein endothelial cells (HUVECs). Both administration of H2S and NaHS, as well as endogenous H2S, reduced NO formation, endothelial nitric oxide synthase (eNOS) activity, eNOS transcript abundance, and l-arginine (l-Arg) transport (all P < 0.01). The kinetics analysis of eNOS activity and l-Arg transport showed that H2S reduced Vmax values (all P < 0.01) without modifying Km parameters. Use of selective NOS inhibitors verified that eNOS [vs. inducible NOS (iNOS) and neuronal NOS (nNOS)] was the specific target of H2S regulation. H2S treatment (100 μmol/l) reduced Akt phosphorylation and decreased eNOS phosphorylation at Ser1177. H2S reduced l-Arg uptake by inhibition of a system y+ transporter and decreased the CAT-1 transcript. H2S treatment reduced protein expression of eNOS but not of nNOS and iNOS. Pinacidil (KATP channel opener) exhibited the similar inhibitory effects on the l-Arg/NOS/NO pathway. Glibenclamide (KATP channel inhibitor) partly blocked the inhibitory effect of H2S and pinacidil. An in vivo experiment revealed that H2S downregulated the vascular l-Arg/eNOS/NO pathway after intraperitoneal injection of NaHS (14 μmol/kg) in rats. Taken together, our findings suggest that H2S downregulates the vascular l-Arg/NOS/NO pathway in vitro and in vivo, and the KATP channel could be involved in the regulatory mechanism of H2S.


2019 ◽  
Vol 5 ◽  
pp. 8-17 ◽  
Author(s):  
Lujuan Xing ◽  
MacKenzie E. Chee ◽  
Hua Zhang ◽  
Wangang Zhang ◽  
Yoshinori Mine

Carnosine is a natural dipeptide synthesized by both vertebrate and invertebrate organisms and has functional properties that are specific to muscle and excitable tissues. Recent in vivo and in vitro studies have shown that carnosine presents metal chelating and antioxidant activities and has the ability to inhibit protein carbonylation and glycoxidation. This review describes the health benefits of carnosine in relation to its bioaccessibility, bioavailability and biochemical properties as well as providing the current state-of-the-art knowledge on the potential use of carnosine as a nutraceutical. The therapeutic potential of carnosine has also been investigated by a number of preclinical and clinical studies for diseases such as diabetes and its associated complications, as well as fatigue, ageing, and some neurological disorders. Altogether the current literature provides supportive evidence on the use of carnosine as a natural dietary supplement with significant health boosting efficiency and without any side effects.


2005 ◽  
Vol 288 (5) ◽  
pp. L868-L873 ◽  
Author(s):  
Bill T. Ameredes ◽  
Jigme M. Sethi ◽  
He-Liang Liu ◽  
Augustine M. K. Choi ◽  
William J. Calhoun

Interleukin (IL)-10 is an anti-inflammatory cytokine implicated in the regulation of airway inflammation in asthma. Among other activities, IL-10 suppresses production of nitric oxide (NO); consequently, its absence may permit increased NO production, which can affect airway smooth muscle contractility. Therefore, we investigated airway reactivity (AR) in response to methacholine (MCh) in IL-10 knockout (−/−) mice compared with wild-type C57BL/6 (C57) mice, in which airway NO production was measured as exhaled NO (ENO), and NO production was altered with administration of either NO synthase (NOS)-specific inhibitors or recombinant murine (rm)IL-10. AR, measured as enhanced pause in vivo, and tracheal ring tension in vitro were lower in IL-10−/− mice by 25–50%, which was associated with elevated ENO levels (13 vs. 7 ppb). Administration of NOS inhibitors NG-nitro-l-arginine methyl ester (8 mg/kg ip) or l- N6-(1-iminoethyl)-lysine (3 mg/kg ip) to IL-10−/− mice decreased ENO by an average of 50%, which was associated with increased AR, to levels similar to C57 mice. ENO in IL-10−/− mice decreased in a dose-dependent fashion in response to administered rmIL-10, to levels similar to C57 mice (7 ppb), which was associated with a 30% increment in AR. Thus increased NO production in the absence of IL-10, decreased AR, which was reversed with inhibition of NO, either by inhibition of NOS, or with reconstitution of IL-10. These findings suggest that airway NO production can modulate airway smooth muscle contractility, resulting in airway hyporesponsiveness when IL-10 is absent.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Enhui Cui ◽  
Xiaoyan Zhi ◽  
Ying Chen ◽  
Yuanyuan Gao ◽  
Yunpeng Fan ◽  
...  

Objectives. To investigate the anti-inflammatory effect ofCoptis chinensisplus myrobalan (CM) in vitro and in vivo.Methods. The inflammation in mouse peritoneal macrophages was induced by lipopolysaccharide (LPS). Animal models were established by using ear swelling and paw edema of mouse induced by xylene and formaldehyde, respectively. In vitro, cytotoxicity, the phagocytosis of macrophages, the levels of nitric oxide (NO), induced nitric oxide synthase (iNOS), tumor necrosis factor-α(TNF-α), and interleukin-6 (IL-6) in cell supernatant were detected. In vivo, swelling rate and edema inhibitory rate of ear and paw were observed using CM-treated mice.Results. At 150–18.75 μg·mL−1, CM had no cytotoxicity and could significantly promote the growth and the phagocytosis of macrophages and inhibit the overproduction of NO, iNOS, TNF-α, and IL-6 in macrophages induced by LPS. In vivo, pretreatment with CM, the ear swelling, and paw edema of mice could be significantly inhibited in a dose-dependent manner, and the antiedema effect of CM at high dose was better than dexamethasone.Conclusion. Our results demonstrated thatCoptis chinensisand myrobalan possessed synergistically anti-inflammatory activities in vitro and in vivo, which indicated that CM had therapeutic potential for the prevention and treatment of inflammation-mediated diseases.


2021 ◽  
Author(s):  
Poonam Parashar ◽  
Shalini Gautam ◽  
Neelu Singh ◽  
Jovita Kanoujia ◽  
Abhishek Yadav ◽  
...  

Abstract The present investigation deals with solubility enhancement of Etodolac (ETD) through co-crystals technique utilizing various co-formers and to evaluate their therapeutic efficacy against carrageenan-induced inflammation. Co-formers citric acid anhydrous and tartaric acid were selected to formulate ETD co-crystals to improve solubility and dissolution employing neat grinding technique. The prepared co-crystals were characterized for solubility enhancement, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), in vitro dissolution and stability studies. The co-crystals were further investigated for in vivo studies to assess their potential to cure paw edema in mice. The outcome of the study illustrated significantly improved solubility and dissolution of ETD up to 6.15 folds using citric acid. Approximately a two-fold reduction in nitric oxide and cytokines levels was observed with optimized formulation. Also, substantial inhibition of inflammation was observed in paw edema induced animals. In sight of the above results the co-crystal approach could be an alternative for enhanced therapeutic potential.


Author(s):  
Christopher Viney

Light microscopy is a convenient technique for characterizing molecular order in fluid liquid crystalline materials. Microstructures can usually be observed under the actual conditions that promote the formation of liquid crystalline phases, whether or not a solvent is required, and at temperatures that can range from the boiling point of nitrogen to 600°C. It is relatively easy to produce specimens that are sufficiently thin and flat, simply by confining a droplet between glass cover slides. Specimens do not need to be conducting, and they do not have to be maintained in a vacuum. Drybox or other controlled environmental conditions can be maintained in a sealed chamber equipped with transparent windows; some heating/ freezing stages can be used for this purpose. It is relatively easy to construct a modified stage so that the generation and relaxation of global molecular order can be observed while specimens are being sheared, simulating flow conditions that exist during processing. Also, light only rarely affects the chemical composition or molecular weight distribution of the sample. Because little or no processing is required after collecting the sample, one can be confident that biologically derived materials will reveal many of their in vivo structural characteristics, even though microscopy is performed in vitro.


2019 ◽  
Vol 24 (39) ◽  
pp. 4626-4638 ◽  
Author(s):  
Reyhaneh Moradi-Marjaneh ◽  
Seyed M. Hassanian ◽  
Farzad Rahmani ◽  
Seyed H. Aghaee-Bakhtiari ◽  
Amir Avan ◽  
...  

Background: Colorectal cancer (CRC) is one of the most common causes of cancer-associated mortality in the world. Anti-tumor effect of curcumin has been shown in different cancers; however, the therapeutic potential of novel phytosomal curcumin, as well as the underlying molecular mechanism in CRC, has not yet been explored. Methods: The anti-proliferative, anti-migratory and apoptotic activity of phytosomal curcumin in CT26 cells was assessed by MTT assay, wound healing assay and Flow cytometry, respectively. Phytosomal curcumin was also tested for its in-vivo activity in a xenograft mouse model of CRC. In addition, oxidant/antioxidant activity was examined by DCFH-DA assay in vitro, measurement of malondialdehyde (MDA), Thiol and superoxidedismutase (SOD) and catalase (CAT) activity and also evaluation of expression levels of Nrf2 and GCLM by qRT-PCR in tumor tissues. In addition, the effect of phytosomal curcumin on angiogenesis was assessed by the measurement of VEGF-A and VEGFR-1 and VEGF signaling regulatory microRNAs (miRNAs) in tumor tissue. Results: Phytosomal curcumin exerts anti-proliferative, anti-migratory and apoptotic activity in-vitro. It also decreases tumor growth and augmented 5-fluorouracil (5-FU) anti-tumor effect in-vivo. In addition, our data showed that induction of oxidative stress and inhibition of angiogenesis through modulation of VEGF signaling regulatory miRNAs might be underlying mechanisms by which phytosomal curcumin exerted its antitumor effect. Conclusion: Our data confirmed this notion that phytosomal curcumin administrates anticancer effects and can be used as a complementary treatment in clinical settings.


2020 ◽  
Vol 26 ◽  
Author(s):  
Kondeti Ramudu Shanmugam ◽  
Bhasha Shanmugam ◽  
Gangigunta Venkatasubbaiah ◽  
Sahukari Ravi ◽  
Kesireddy Sathyavelu Reddy

Background : Diabetes is a major public health problem in the world. It affects each and every part of the human body and also leads to organ failure. Hence, great progress made in the field of herbal medicine and diabetic research. Objectives: Our review will focus on the effect of bioactive compounds of medicinal plants which are used to treat diabetes in India and other countries. Methods: Information regarding diabetes, oxidative stress, medicinal plants and bioactive compounds were collected from different search engines like Science direct, Springer, Wiley online library, Taylor and francis, Bentham Science, Pubmed and Google scholar. Data was analyzed and summarized in the review. Results and Conclusion: Anti-diabetic drugs that are in use have many side effects on vital organs like heart, liver, kidney and brain. There is an urgent need for alternative medicine to treat diabetes and their disorders. In India and other countries herbal medicine was used to treat diabetes. Many herbal plants have antidiabetic effects. The plants like ginger, phyllanthus, curcumin, aswagandha, aloe, hibiscus and curcuma showed significant anti-hyperglycemic activities in experimental models and humans. The bioactive compounds like Allicin, azadirachtin, cajanin, curcumin, querceitin, gingerol possesses anti-diabetic, antioxidant and other pharmacological properties. This review focuses on the role of bioactive compounds of medicinal plants in prevention and management of diabetes. Conclusion: Moreover, our review suggests that bioactive compounds have the potential therapeutic potential against diabetes. However, further in vitro and in vivo studies are needed to validate these findings.


2020 ◽  
Vol 16 (8) ◽  
pp. 1147-1156
Author(s):  
Ruchi Singh ◽  
Syed M. Hasan ◽  
Amit Verma ◽  
Sanjay K. Panda

Background: A plant is a reservoir of potentially useful active chemical entities which act as drugs as well as intermediates for the discovery of newer molecules and provide newer leads for modern drug synthesis. The demand for new compounds in the field of medicine and biotechnology is centuries old and with a rise in chronic diseases and resistance to existing drugs in the field of anti-infective agents, the chemicals obtained from plant sources have been an area of attraction. The whole plant has possessed multiple pharmacological activities. This is scientifically established by in-vivo and in-vitro studies. Methods: Various electronic databases such as PubMed, Science Direct, Scopus and Google were searched to collect the data of the present review. All the collected information is categorized into different sections as per the aim of the paper. Results: Fifty-six research and review papers have been studied and were included in this review article. After a detailed study, we provide a significant description of various phytochemicals present in Nyctanthes arbor-tristis Linn., which is responsible for various pharmacological activities. Twenty of studied articles gives a general introduction and ethnobotanical information about the plant, two papers contained microscopic detail of leaf and fruit. Twenty papers contained information about the phytoconstituents present in different parts of Nyctanthes arbor-tristis plant and fourteen articles reported pharmacological activities like antioxidant, anti-inflammatory, antiarthritic, antimicrobial and immunobiotic activity. Conclusion: This review explores the published research work comprising the ethnobotanical description of the subjected plant, distribution, phytochemical profile, and arthritis-related pharmacological activities.


Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Robin Park ◽  
Andrew L. Coveler ◽  
Ludimila Cavalcante ◽  
Anwaar Saeed

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.


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