The potential effects of Caper (Capparis spinosa L.) in the treatment of diabetic neuropathy

Diabetic neuropathy (DN) is the most common form of neuropathy worldwide, with its prevalence rising alongside diabetes, and being characterized by sensory, motor or autonomic symptoms. DN is considered to be an incurable complication of diabetes, the management of which mainly consists of improving glycemic control, managing pain relief and ensuring continuous foot care. Although gabapentin, duloxetine and tricyclic antidepressants are commonly used to reduce patient symptoms, they do not affect the pathophysiology and progression of neuropathy. Furthermore, these drugs can have various side effects including insomnia, decreased appetite, arrhythmia, heart failure, and suicidal behavior. According to traditional Persian medicine, DN is recognized as a type of "Khadar" or "Esterkha" (a sensory or motor disorder, respectively) that occurs due to the accumulation of sugars in the peripheral nerves. Capparis spinosa L., commonly known as the caper plant, has been recommended in authentic sources of traditional Persian medicine to treat such disorders. In this study, we reviewed the pharmacological properties of C. spinosa using the Web of Science, PubMed, Scopus and Google Scholar databases, and found that Capparis spinosa L. could affect several pathways involved in DN pathogenesis, including aldose reductase activity, the secretion of inflammatory mediators (IL-17, TNF-alpha, IL-1 beta, IL-6), oxidative stress, hyperlipidemia, hyperglycemia and advanced glycation end product formation. Based on these findings, we hypothesize that Capparis spinosa L., may prevent the progression and reduce the symptoms of diabetic neuropathy, and so can be considered as a complementary treatment in this disorder. This hypothesis should be evaluated in well-designed in vitro and in vivo studies, and through clinical trials.