Neuropathy or neuropathic pain is a major therapeutic challenge affecting many people worldwide. Neuropathies are diseases characterized by allodynia, hyperalgesia, and paraesthesia. Between 1966 to 2012, the incidence and prevalence of neuropathic pain increased from 3% to 17%. Studies have shown that neuropathy affects 4-6% of the general population of which 22% is chronic and 74% is moderate or severe pain. Neuropathic pain disturbs the quality of life by affecting the physiological, psychological, and social behavior of patients.
Neuropathic pain affects 16-26% of patients suffering from diabetes and 50% of patients receiving anticancer agents develop peripheral neuropathy within 2 weeks that continues for three months after treatment finishes. Crush injuries are also a cause of neuropathies due to a lack of proper treatment for prolonged bedridden patients. A recent study revealed that neuropathy leads to the development of anxiety and depression in 9% of the adult population. An increase in the incidence of diabetic neuropathy is also considered the reason for an increase in these numbers. Therefore, neuropathy or neuropathic pain being observed can be caused by anticancer-induced pain, diabetic-induced pain, or as a result of a direct effect on the nerves or spinal cord.
In clinical practice in Ayurveda, for example, curcumin and shilajit are agents commonly used for attenuating the painful symptoms associated with neuropathic pain. Recently, other compounds have been investigated including emodin, puerarin and resveratrol for preventing symptoms and improving quality of life.
The pathogenesis of neuropathy involves the up-regulation of inflammatory mediators. In addition, when injured, microglial cells release brain-derived neurotrophic factors activating purinergic receptors. Purinergic receptors are ion-gated receptors (calcium channels) present on the spinal microglial cells and thought to be involved in neurological pathologies. This overall process is regulated by the p38 mitogen-activated protein kinase. In some cases of neuropathy, the demyelination of the nerve cells affects nerve conduction. The conduction velocity (motor nerve conduction velocity) is markedly reduced in neuropathies. Nerve damage is also associated with chronic constriction injury, the permanent increase of sugar levels and toxicity caused by anticancer agents, which also reduced motor nerve conduction velocity (MNCV). As neuropathic pain is a chronic illness, several studies using animal models to predict anxiety and depressive-like behaviour have been carried out. The therapeutic approach to recover mental status is also important to improve quality of life. Exploration of the effect of these compounds and possible mechanism is required.
Currently, there is a limited range of treatments available, many with major adverse drug reactions. The aim of this Research Topic is to determine more fruitful candidates for treating and managing neuropathic pain. In particular, medicinal plants are of importance in attenuating various forms of neurodegenerative and neuro-inflammatory disorders. The agents of natural origin exert their effects to reduce neuronal loss by anti-oxidant, anti-inflammatory, anti-apoptotic and neurotrophic activities. Low toxicity treatments for these diseases are of great benefit. Furthermore, this collection aims to collate data on active compounds effective in neuropathic pain treatment which can be further investigated with the aim to develop treatments.
This Research Topic welcomes review and original research articles that look at natural products to treat diabetic-induced, anti-cancer-treatment induced or chronic constriction injury-induced neuropathic pain. Researchers are invited to contribute research, supported by both computational and molecular investigations. We welcome studies that use an experimental approach or ones which integrate experimental and detailed in silico methods (normally only for individual metabolites). Papers using solely in silico approaches are far too preliminary, of no pharmacological relevance and consequently will not be considered.
Articles with a focus on, but not limited to, the following topics and related themes are welcome:
1. Experimental studies in combination with computational analysis of compounds and their molecular dynamic simulation.
2. Treatment of pain-related behavioral disturbances and disturbances at CNS level (anxiety and depression).
3. Nerve and spinal conduction velocities to predict neuronal signals.
4. Molecular techniques.
All the manuscripts submitted to the collection will need to fully comply with the
Four Pillars of Best Practice in Ethnopharmacology (you can freely download the full version
here. Particular attention must be paid to the requirements for the characterisation of the herbal preparations used and to the use of therapeutically relevant dose levels’. Purely in silico studies will not be accepted.
