Exp Eye Res . 2020 Nov;200:108232. doi: 10.1016/j.exer.2020.108232. Epub 2020 Sep 9. Effect of NADPH oxidase inhibitors in an experimental retinal model of excitotoxicity Stavroula Dionysopoulou 1, Per Wikström 2, Erik Walum 3, Kyriaki Thermos 4


NADPH oxidases (NOX) are activated in ischemic conditions leading to increases in reactive oxygen species (ROS) and neurotoxicity. The aim of the present study was to investigate the role of NOX in the development of retinal pathologies, associated with excitotoxicity and the evaluation of NOX inhibitors as putative therapeutic agents. Sprague-Dawley rats were used for the induction of the in vivo retinal model of (RS)-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid hydrobromide (AMPA) excitotoxicity. Rats were intravitreally administered with PBS, AMPA (42 nmoles) or AMPA + NOX inhibitors, VAS2870 (pan-NOX inhibitor, 10-6-10-4 M), ML171 (NOX1 inhibitor, 10-5, 10-4 M), and GLX7013114 (NOX4 inhibitor, 10-4 M). Immunohistochemical studies were performed using antibodies raised against nitrotyrosine, a ROS/oxidative stress marker, bNOS, a neuronal marker for nitric oxide synthase and the macro and microglia markers, glial fibrillary acidic protein and ionized calcium-binding adaptor molecule-1, respectively. VAS2870 and ML171 showed neuroprotective and anti-inflammatory actions reversing the AMPA induced reduction of bNOS expressing amacrine cells and attenuating macro/microglial activation. GLX7013114 (10-4 M) did not protect bNOS expressing amacrine cells, but it did attenuate the AMPA induced increase in nitrotyrosine positive cells and activation of glial cells. These results suggest that NOX1, NOX4 and possibly NOX2 (due to the actions of VAS2870) play an important role in the pathophysiology of the retina and that NOX inhibitors are putative neuroprotective and anti-inflammatory agents against retinal abnormalities caused by excitotoxicity.

Bringing Glucox Biotech AB closer to the clinic


Glucox Biotech (GB) has entered into a new exciting phase by adding strong scientific and business competence into the management. Recently Alan Harris, with extensive management experience from the pharmaceutical industry, will be part of the GB board. Alan is presently holding a leading position at Ferring Pharmaceuticals and he will be a significant asset to bring GB substances into the clinic

Björn Sundeby with a long history of being a successful business man and entrepreneur is presently the main owner of GB. Björn Sundeby has a strong focus to bring businesses into success stories.

Per Wikström, being one of the founders of GB, has taken the role as the new CEO. Erik Walum the previous CEO has decided to stay as a passive owner in the company.

A new European patent application 18171556.6 regarding the latest development of highly selective Nox4 inhibitors was applied May 9, 2018.


Eurostars project reaches unique Nox-4 inhibitors

The Eurostar supported project ”Neuroprotective therapy for ischemic stroke” a collaboration between Glucox Biotech AB (GB) and prof. Harald Schmidt at Maastricht University (UM) is approaching its finalization.

Early restoration of cerebral blood is essential to minimize brain damage that will occur in an ischemic stroke event.  The paradox that more damage occurs at the return of the blood flow is well known. Prof. Harald Schmidt has previously demonstrated the importance of enhanced NADPHoxidase 4 (Nox4) activity, in this pathological event, generating reactive oxygen which aggravates tissue damage and brain damage.

Thus a pharmaceutical that efficiently and selective inhibits Nox4 over activity is a hot candidate to minimize the brain damage that will occur in an ischemic stroke.

From GBs portfolio of Nox4 inhibitors four structurally different hits GLX481304, GLX351322, GLX351320, GLX701313 has been developed in a SAR medicinal program (GB) and tested in in vitro/in vivo-stroke models (UM).

The two SAR developed Nox4 inhibitors GLX7013114 and GLX7013107 originating from the hit GLX701313 demonstrate the highest selectivity to Nox4 inhibition in relation to other Nox-isoforms and are presently the most important Nox4 inhibitors in this project. These inhibitors demonstrate neuroprotective effect in two different in vitro stroke models at UM:”Hippocampal Brain Slices” (HBS) and ”Human Brain Micro vascular Endothelial Cells” (HBMEC) that were subjected to oxygen and glucose deprivation.  FTIA without adverse effects and PK results provided the foundation of on-going in vivo study in mice stroke models.

The table show efficiency of the inhibitory action and selectivity in whole cell-assays expressing Nox-isoforms, and also the lack of ability to inhibit Xanthine Oxidase (XO). No endogenous redox activity of the two compounds was detected.

Nox4 IC50 micro molar Nox1IC50 micro molar Nox2IC50 micro molar Nox5IC50 micro molar XOIC50 micro molar Endogenous redox activity
GLX7013114 0.3 >200 >200 >200 >200 0
GLX7013107 2.4 >200 >200 >200 >200 0

Glucox receives financing from Vinnova

Glucox Biotech has success in Eurostars grant application and receives financing for compound development and stroke investigation in joint project with Maastricht University.

As a result of a successful application to the EU program Eurostars, Vinnova has grated Glucox Biotech financing for the project Neuroprotective Therapy for Ischemic Stroke. At the same time the Dutch authorities has granted Prof. Schmidt at Maastricht University funds for his part of the project.

Through collaboration with Maastricht University we aim to further develop our Nox4 inhibitors, including lead optimization, pharmacokinetics, ADMET, formulation development, proof of principle in animal studies and preclinical toxicology.

Recently, the group of Prof. Schmidt at Maastricht provided proof of concept that NOX4 represents a highly promising novel, mechanism-based therapeutic target for ischemic stroke. They showed that deletion of NOX4 in mice, but not of NOX1 or NOX2, not only massively reduces infarct sizes upon ischemic strokes, but also results in better neurological outcomes, protection of the blood-brain barrier, and improved survival.

As deletion of NOX4 in mice does not result in any apparent basic phenotype, its acute inhibition in humans after ischemic strokes is likely a safe therapy. Moreover, treatment of stroke patients with NOX4 inhibitors should not increase the risk of bleedings in case of a haemorrhagic stroke, as it is currently the case for the approved drug. Thus, the treatment could be started without the need for a CT scan.

Agreement with Maastricht University

Glucox Biotech has signed an agreement with Prof. Harald Schmidt of Maastricht University for further development of Glucox´ lead compound for treatment of ischemic stroke.

It has recently been shown that NOX4 is an effective therapeutic target in acute stroke. Prof. Harald Schmidt and his team have convincingly shown that significant increase in NOX4 activity is a main component in neuronal cell death that occurs in ischemic stroke. Within the collaboration Prof. Schmidt and co-workers will evaluate Glucox’ NOX4 inhibitors for further development into pharmaceuticals that will prevent neuronal cell death in ischemic stroke.

Ref: Radermacher, K., A., et al (2012) Experimental & Translational Stroke Medicine, 4:11 doi: 10.1186/2040-7378-4-11

Agreement with Accelera

Glucox Biotech has signed an agreement with Accelera Srl, Milano, Italy. Accelera will evaluate pharmacokinetics and time course of brain uptake of Glucox’ lead compounds in mice.

Two of Glucox’ NOX4 small molecule inhibitors have been shown to protect brain from nerve cell damage in a situation of induced acute ischemic stroke. To further elucidate the positive action of these compounds, time course of brain uptake will be investigated and evaluated.

SMURF grant to Glucox and Prof. Nils Welsh

Uppsala University and SLU have together with the European Regional Development Fund alloted Glucox Biotech and Professor Nils Welsh a SMURF grant for further studies of the protective action of Glucox´ lead compounds on beta cells.

In a pilot study one of Glucox´ proprietary specific Nox4 inhibitor compounds was found to protect beta cells in isolated pancreatic islets from high glucose induced cell death. The grant will be used to verify and elucidate the significance of this first observation. The project involves experiments in several different models.

Agreement with Karolinska Institutet

Glucox Biotech has signed an agreement with Prof. Anders Arner of Karolinska Institutet for further testing of Glucox smal molecule NOX4 inhibitors in diabetic models.

Prof. Arner, Department of Physiology and Pharmacology, Division of Genetic Physiology, Karolinska Institutet, Stockholm has agreed to investigate the influence of several of Glucox’ proprietary compounds on parameters relevant to metabolic diseases in diabetic models.

Ref: Samocha-Bonet, D., et al (2009) Trends in Endocrinology and Metabolism, 21 (2), 83-88

X. Wu and coworkers show importance of NOX4 in insulin resistance

Wu and coworkers undertook characterization of pathway-selective insulin resistance and responsivenes in liver and hepatocytes by examining targets of the insulin receptor including NOX4 pathways. They comcluded that functional disturbance of a single molecule, NAD(P)H oxidase 4, is sufficient to induce the key harmful features of deranged insulin signaling in type 2 diabetes mellitus, obesity, and other conditions associated with hyperinsulinemia and pathway-selective insulin resistance and responsiveness.

Ref: Wu, X., et al (2012) Arterioscler Thromb Vasc Biol. 2012 Feb 9. (Epubl ahead of print)

New publication from Glucox Biotech and academic partners

The mission of Glucox Botech is to identify compounds that improve glucose homeostasis. Together with two acadmic groups at Karolinska Institutet and Stockholm University, Glucox Biotech has shown that shikonin, a naphthoquinone derived from the Cinese plant Lithospermum erythrorhizon, increases glucose uptake i skeletal muscle cells.

Shikonin increases uptake via an insulin-independent, calcium dependent, pathway. The beneficial effects of shikonin on glucose metabolism, both in vitro and in vivo, show that the compound possesses properties that make it of considerable interest for developing novel treatments of type 2 diabetes.

Ref: Öberg, A.I., et al (2011) PLoS One, 6 (7): e22510