Study of therapeutic effects of curcumin on in vitro and in vivo models of peripheral neuropathies ; Etude des effets thérapeutiques de la curcumine dans des modèles in vitro et in vivo de neuropathies périphériques

Peripheral nerves are subject to many pathologies and the etiology of peripheral neuropathies (PN) is vast (metabolic disorders, infections, toxins, physical injuries and genetic mutations, etc.). For example, PN of traumatic origin are common and are characterized by a called Wallerian degeneration of nerve fibres. Another example is Charcot-Marie-Tooth disease 1A (CMT1A), which is the most common hereditary genetic PN. It is characterized by an overexpression of the PMP22 protein involved in maintaining the myelin sheath. Currently, there is no pharmacological treatment for these two nerve disorders. Recently, interest in the role of dietary antioxidants, such as curcumin, has led to much research. This molecule has long been used in Asian medicine for its therapeutic properties. However, it has a very low bioavailability and therefore requires the use of very high doses to obtain beneficial effects. In a first study, our results showed that low doses of curcumin administered locally and continuously improve functional recovery, electrophysiological and histological parameters, and expression of major myelin proteins in a rat sciatic nerve crush model. These beneficial effects have been attributed to the antioxidant properties of curcumin. In a second study, our results showed that a low dose of curcumin nanocrystals (Nano-Cur), injected in IP, improves phenotype, electrophysiological and histological parameters in a transgenic model of CMT1A rats. In this study, the positive effects were attributed to the antioxidant properties of the Nano-cur, coupled with the activation of the endoplasmic reticulum associated degradation pathway, allowing the reduction of harmful overexpression of PMP22 in CMT1A rats. All these results show that the administration of low doses of curcumin is a promising treatment for peripheral nerve repair ; Les nerfs périphériques sont sujets à de nombreuses pathologies et l’étiologie des neuropathies périphériques (NP) est vaste (troubles métaboliques, infections, toxines, blessures ...