Bioactive Nutraceuticals in Diabetic Neuropathy: Mechanistic Insights and Gaps in Clinical Translation

Diabetic neuropathy (DN) serves as a widespread and incapacitating complication that affects almost fifty percent of diabetes mellitus patients while causing severe chronic pain and sensory impairment and raising the chances of limb amputation. The disease develops through multiple interconnected pathways that start with polyol pathway hyperactivity, lead to RAGE signalling by advanced glycation endproducts, and then to oxidative stress, nitrosative stress, chronic inflammation, and, finally, mitochondrial dysfunction. Existing drug treatments only address symptoms of medical conditions, yet they yield minimal benefit while causing harmful side effects, underscoring the need for treatments that target specific disease mechanisms. This review aims to provide a mechanistically oriented evaluation of bioactive nutraceuticals and their potential role in modulating key pathogenic pathways driving diabetic nephropathy, while also identifying essential research requirements for clinical application.

The researchers conducted a narrative synthesis of existing studies examining the primary categories of bioactive nutraceuticals, including polyphenols and flavonoids, phenolic acids, organosulfur compounds, isothiocyanates, and terpenoids. The research focused on how these substances affected the biological processes that generate oxidative stress and inflammation, leading to mitochondrial dysfunction and metabolic disorders.

Preclinical evidence suggests that various nutraceutical compounds, including epigallocatechin gallate, resveratrol, curcumin, chlorogenic acid, S-allyl cysteine, sulforaphane, and cinnamaldehyde, demonstrate neuroprotective effects by controlling different disease-related mechanisms. The compounds show the ability to decrease oxidative stress while also blocking inflammatory pathways and enhancing mitochondrial performance, and they help to restore metabolic equilibrium. The existing evidence mainly comes from laboratory and animal research, as few high-quality clinical studies specifically examine human outcomes in neuropathic conditions. The field faces major obstacles due to low bioavailability, unstandardized extract products, inconsistent dosing methods, and insufficient understanding of pharmacokinetic properties.

Bioactive nutraceuticals serve as a multi-target therapeutic approach with potential for treating diabetic neuropathy. Yet their translation into clinical use faces major obstacles that restrict their application. The research work should focus on developing standard product formulas together with advanced delivery methods and comprehensive clinical studies, which will demonstrate product effectiveness, safety, and medical value in human subjects.