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.