Oxy-imino saccharidic derivatives as a new structural class of aldose reductase inhibitors endowed with anti-oxidant activity

The challenging inhibition of Aldose Reductase for the treatment of diabetic complications: a 2019-2023 update of the patent literature

INTRODUCTION

Aldose reductase (AKR1B1, EC: 1.1.1.21) is a recognized target for the treatment of long-term diabetic complications since its activation in hyperglycemia and role in the polyol pathway. In particular, the tissue-specificity of AKR1B1 expression makes the design of the traditional Aldose Reductase Inhibitors (ARIs) and the more recent Aldose Reductase Differential Inhibitors (ARDIs) exploitable strategies to treat pathologies resulting from diabetic conditions.

AREAS COVERED

A brief overview of the roles and functions of AKR1B1 along with known ARIs and ARDIs was provided. Then, the design of the latest inhibitors in the scientific scenario was discussed, aiming at introducing the research achievement in the field of intellectual properties. Patents dealing with AKR1B1 and diabetes filed in the 2019-2023 period were collected and analyzed. Reaxys, Espacenet, SciFindern, and Google Patents were surveyed, using 'aldose reductase' and 'inhibitor' as the reference keywords. The search results were then filtered by PRISMA protocol, thus obtaining 16 records to review.

EXPERT OPINION

Although fewer in number than in the early 2000s, patent applications are still being filed in the field of ARIs, with a large number of Chinese inventors reporting new synthetic ARIs in favor of the repositioning approach.

The Anti-Hypoxic Mechanism of Sesamoside Determined Using Network Pharmacology

This study aims to elucidate the anti-hypoxia mechanism of sesamoside, an active component of Phlomis younghusbandii Mukerjee, through a network pharmacology approach. Sesamoside has demonstrated potential anti-oxidant and antiglycation activities. The hypoxia-related disease targets were collected from databases like GeneCards and OMIM. Protein-protein interaction (PPI) networks were constructed using the STRING database. GO/KEGG enrichment analysis was performed using the Metascape database to identify biological processes and signaling pathways. Our results indicate that sesamoside interacts with multiple targets related to glucose and lipid metabolism, nucleotide metabolism, and inflammatory, and we find that AKR1B1 (AR) plays a crucial role in sesamoside responses to hypoxia. Molecular docking studies were performed using Autodock software, revealing good binding activity between sesamoside and AR. We then use CCK-8 assay, qPCR, WB, and ELISA analysis to validate the role of sesamoside in regulating AR and participating in anti-hypoxia through cell experiments. The results show that compared with the hypoxia group, sesamoside treatment significantly improves the expression of AR and inflammation cytokines. In summary, this study sheds light on the anti-hypoxia mechanism of sesamoside using a network pharmacology approach, providing a theoretical basis and experimental foundation for its application in the prevention and treatment of hypoxic diseases.

Recent progress and research trend of anti-cataract pharmacology therapy: A bibliometric analysis and literature review

Cataract is the leading cause of blindness worldwide. Cataract phacoemulsification combined with intraocular lens implantation causes great burden to global healthcare, especially for low- and middle-income countries. Such burden would be significantly relieved if cataracts can effectively be treated or delayed by non-surgical means. Excitingly, novel drugs have been developed to treat cataracts in recent decades. For example, oxysterols are found to be able to innovatively reverse lens clouding, novel nanotechnology-loaded drugs improve anti-cataract pharmacological effect, and traditional Chinese medicine demonstrates promising therapeutic effects against cataracts. In the present review, we performed bibliometric analysis to provide an overview perspective regarding the research status, hot topics, and academic trends in the field of anti-cataract pharmacology therapy. We further reviewed the curative effects and molecular mechanisms of anti-cataract drugs such as lanosterol, metformin, resveratrol and curcumin, and prospected the possibility of their clinical application in future.

Implications of Diabetes-Induced Altered Metabolites on Retinal Neurodegeneration

Diabetic retinopathy (DR) is one of the major complications of diabetic eye diseases, causing vision loss and blindness worldwide. The concept of diabetic retinopathy has evolved from microvascular disease into more complex neurovascular disorders. Early in the disease progression of diabetes, the neuronal and glial cells are compromised before any microvascular abnormalities clinically detected by the ophthalmoscopic examination. This implies understanding the pathophysiological mechanisms at the early stage of disease progression especially due to diabetes-induced metabolic alterations to damage the neural retina so that early intervention and treatments options can be identified to prevent and inhibit the progression of DR. Hyperglycemia has been widely considered the major contributor to the progression of the retinal damage, even though tight control of glucose does not seem to have a bigger effect on the incidence or progression of retinal damage that leads to DR. Emerging evidence suggests that besides diabetes-induced hyperglycemia, dyslipidemia and amino acid defects might be a major contributor to the progression of early neurovascular retinal damage. In this review, we have discussed recent advances in the alterations of key metabolites of carbohydrate, lipid, and amino acids and their implications for neurovascular damage in DR.

Nature-Inspired O-Benzyl Oxime-Based Derivatives as New Dual-Acting Agents Targeting Aldose Reductase and Oxidative Stress

Aldose reductase (ALR2) is the enzyme in charge of developing cellular toxicity caused by diabetic hyperglycemia, which in turn leads to the generation of reactive oxygen species triggering oxidative stress. Therefore, inhibiting ALR2 while pursuing a concomitant anti-oxidant activity through dual-acting agents is now recognized as the gold standard treatment for preventing or at least delaying the progression of diabetic complications. Herein we describe a novel series of (E)-benzaldehyde O-benzyl oximes 6a-e, 7a-e, 8a-e, and 9-11 as ALR2 inhibitors endowed with anti-oxidant properties. Inspired by the natural products, the synthesized derivatives are characterized by a different polyhydroxy substitution pattern on their benzaldehyde fragment, which proved crucial for both the enzyme inhibitory activity and the anti-oxidant capacity. Derivatives (E)-2,3,4-trihydroxybenzaldehyde O-(3-methoxybenzyl) oxime (7b) and (E)-2,3,4-trihydroxybenzaldehyde O-(4-methoxybenzyl) oxime (8b) turned out to be the most effective dual-acting products, proving to combine the best ALR2 inhibitory properties with significant anti-oxidant efficacy.

Synthesis, Molecular Docking Analysis and Biological Evaluations of Saccharide-Modified Thiadiazole Sulfonamide Derivatives

A series of saccharide-modified thiadiazole sulfonamide derivatives has been designed and synthesized by the “tail approach” and evaluated for inhibitory activity against carbonic anhydrases II, IX, and XII. Most of the compounds showed high topological polar surface area (TPSA) values and excellent enzyme inhibitory activity. The impacts of some compounds on the viability of HT-29, MDA-MB-231, and MG-63 human cancer cell lines were examined under both normoxic and hypoxic conditions, and they showed certain inhibitory effects on cell viability. Moreover, it was found that the series of compounds had the ability to raise the pH of the tumor cell microenvironment. All the results proved that saccharide-modified thiadiazole sulfonamides have important research prospects for the development of CA IX inhibitors.

Clinical and Molecular-Genetic Insights into the Role of Oxidative Stress in Diabetic Retinopathy: Antioxidant Strategies and Future Avenues

Reactive oxygen species (ROS) overproduction and ROS-signaling pathways activation attack the eyes. We evaluated the oxidative stress (OS) and the effects of a daily, core nutritional supplement regimen containing antioxidants and omega 3 fatty acids (A/ω3) in type 2 diabetics (T2DM). A case-control study was carried out in 480 participants [287 T2DM patients with (+)/without (-) diabetic retinopathy (DR) and 193 healthy controls (CG)], randomly assigned to a daily pill of A/ω3. Periodic evaluation through 38 months allowed to outline patient characteristics, DR features, and classic/OS blood parameters. Statistics were performed by the SPSS 24.0 program. Diabetics displayed significantly higher circulating pro-oxidants (p = 0.001) and lower antioxidants (p = 0.0001) than the controls. Significantly higher plasma malondialdehyde/thiobarbituric acid reactive substances (MDA/TBARS; p = 0.006) and lower plasma total antioxidant capacity (TAC; p = 0.042) and vitamin C (0.020) was found in T2DM + DR versus T2DM-DR. The differential expression profile of solute carrier family 23 member 2 (SLC23A2) gene was seen in diabetics versus the CG (p = 0.001), and in T2DM + DR versus T2DM - DR (p < 0.05). The A/ω3 regime significantly reduced the pro-oxidants (p < 0.05) and augmented the antioxidants (p < 0.05). This follow-up study supports that a regular A/ω3 supplementation reduces the oxidative load and may serve as a dietary prophylaxis/adjunctive intervention for patients at risk of diabetic blindness.