Title:The Role of Aldose Reductase in Polyol Pathway: An Emerging
Pharmacological Target in Diabetic Complications and Associated
Morbidities
Volume: 25
Issue: 9
Author(s): Jeetendra Kumar Gupta*
Affiliation:
- Department of Pharmacology, Institute of Pharmaceutical Research, GLA University Mathura, Uttar Pradesh, India
Keywords:
Diabetes, neuropathy, nephropathy, retinopathy, sorbitol, aldose reductase, polyol pathway.
Abstract: The expression of aldose reductase leads to a variety of biological and pathological
effects. It is a multifunctional enzyme which has a tendency to reduce aldehydes to the corresponding
sugaralcohol. In diabetic conditions, the aldose reductase enzyme converts glucose into
sorbitol using nicotinamide adenine dinucleotide phosphate as a cofactor. It is a key enzyme in
polyol pathway which is a surrogate course of glucose metabolism. The polyol pathway has a significant
impact on the aetiology of complications in individuals with end-stage diabetes. The exorbitant
level of sorbitol leads to the accumulation of intracellular reactive oxygen species in diabetic
heart, neurons, kidneys, eyes and other vasculatures, leading to many complications and pathogenesis.
Recently, the pathophysiological role of aldose reductase has been explored with multifarious
perspectives. Research on aldose reductase suggest that besides implying in diabetic complications,
the enzyme also turns down the lipid-derived aldehydes as well as their glutathione conjugates.
Although aldose reductase has certain lucrative role in detoxification of toxic lipid aldehydes,
its overexpression leads to intracellular accumulation of sorbitol which is involved in secondary
diabetic complications, such as neuropathy, cataractogenesis, nephropathy, retinopathy and
cardiovascular pathogenesis. Osmotic upset and oxidative stress are produced by aldose reductase
via the polyol pathway. The inhibition of aldose reductase alters the activation of transcription
factors like NF-ƙB. Moreover, in many preclinical studies, aldose reductase inhibitors have been
observed to reduce inflammation-related impediments, such as asthma, sepsis and colon cancer, in
diabetic subjects. Targeting aldose reductase can bestow a novel cognizance for this primordial
enzyme as an ingenious strategy to prevent diabetic complications and associated morbidities. In
this review article, the significance of aldose reductase is briefly discussed along with their prospective
applications in other afflictions.