The safety and efficacy of stem cell therapy for diabetic peripheral neuropathy in animal studies: A systematic review and meta-analysis

Diabetic peripheral neuropathy (DPN) is the most common form of diabetic neuropathy, representing 75% of cases and posing a substantial public health challenge. Emerging evidence from animal studies indicates that stem cell therapy holds significant promise as a potential treatment for diabetic neuropathy. Nevertheless, a comprehensive evaluation of the safety and efficacy of stem cell therapy for DPN in animal studies remains outstanding. A systematic search of MEDLINE, Embase, Scopus, the Web of Science, and the CENTRAL was performed. The time period was up to January 31, 2024. All animal studies investigating the stem cell therapy for treating DPN were included. A random-effects model to combine effect sizes in our meta-analysis was applied. 29 out of the 5431 records met the eligibility criteria. In these studies, stem cell therapy improved motor and sensory nerve conduction velocity, compound muscle action potential (CMAP), and sciatic nerve blood flow. Post-treatment, mechanical and thermal nociceptive thresholds decreased. Rats had significant improvement in axonal circularity, nerve growth factor, and transforming growth factor beta 1; mice had significant increase in weight, CMAP, and angiopoietin 1. The stem cell subgroup analysis showed that dental pulp stem cells had the greatest effects across all parameters, while bone marrow mononuclear cells had strong biochemical responses. Stem cell therapy demonstrates promising efficacy in ameliorating neuropathic symptoms in DPN animal models. Human patient studies and targeted treatment procedures for specific neuropathic disorders are advocated to improve therapeutic outcomes.