Natural molecules as promising players against diabetic peripheral neuropathy: an emerging nutraceutical approach

ABSTRACTDiabetic peripheral neuropathy is one of the most prevalent complications of diabetes mellitus. It is the most common type of neuropathy characterized by decreased sensory functions in the lower extremities and substantial neuropathic pain. Based on clinical characterization, it is classified into symmetric and asymmetric neuropathy. The pathological changes and neuronal function impairment during diabetes are associated with various pathways, including polyol pathway activation, advanced glycation end-products formation, oxidative stress, protein kinase C activation, poly ADP-ribose polymerase, and hexosamine pathways. Demyelination, axonal atrophy, nerve fibre loss, reduced regeneration, and loss of neurovascular interactions are hallmarks. Although some symptomatic and supportive therapies, such as tricyclic agents, antiarrhythmics, opioid analgesics, incretin, aldose reductase, and protein kinase C inhibitors, are in practice, the outcome is not promising. To fill this gap, natural product-based therapy can prove prodigious as an effective alternative. This review aims to comprehend the available literature on the role of various biological molecules in ameliorating diabetic peripheral neuropathy. These molecules play a key role in reducing oxidative-nitrosative stress, aldose reductase activity, and neuronal apoptosis. They control glucose and HbA1c% levels and improve nerve conduction velocity, axonal regeneration, and antioxidant species (catalase, superoxide dismutase, malondialdehyde). They are known for their attenuating thermal and mechanical hyperalgesia and tactile allodynia. Therefore, there is a need to evaluate these molecules at the pre-clinical and clinical levels for efficacy. Hence, natural molecules may act as promising players against diabetic peripheral neuropathy and are a ray of hope for suffering individuals.