Histopathological Effects of the Intrathecal Chondroitinase ABC Administration in Spinal Cord Injured Rats: A Systematic Review.

Introduction: Chondroitinase ABC (ChABC) has been considered a potential treatment for spinal cord injury (SCI). We aim to identify and evaluate the histopathological effects of intrathecal ChABC administration in SCI rat models. Methods: We searched PubMed/MEDLINE, Scopus, Web of Science, Embase, and Cochrane Library for studies published from the inception of each database until November 22, 2022. Results: Of 3857 screened citations, 17 studies met eligibility criteria and were entered into the qualitative analysis. Sixteen studies were of high quality, and one study was of medium quality. The four main rat strains used in studies were Sprague-Dawley, Wistar, Lister hooded, and Long-Evans. ChABC treatment phases were considered acute (within 24 hours after injury), subacute (5 or 7 days after injury), or chronic (4 or 6 weeks after injury). Accordingly, ChABC administration in the acute phase of injury significantly reduced cyst formation and promoted tissue preservation and sensory neuron plasticity. Regardless of the treatment phase, ChABC administration significantly promoted serotonergic and corticospinal fiber plasticity. Nine of the 14 studies reporting on functional outcomes found that ChABC administration, alone or in combination with other treatments, including rehabilitation, improved motor function. Conclusion: The specification of anatomical changes associated with ChABC treatment can explain the functional improvements reported with its use in SCI. The limited studies on more clinically relevant contusion and compression injury models warrant further investigation of these models and alternative treatment phases. Highlights: The current study evaluates the histological effects of Chondroitinase ABC (ChABC) injection into the spinal cord in rat models of spinal cord injury (SCI).Acute-phase administration of ChABC significantly reduced cyst formation and enhanced tissue preservation.It also promoted plasticity and regeneration of sensory neurons.Across all phases, ChABC enhanced serotonergic and corticospinal fiber sprouting, suggesting broad regenerative effects.The anatomical changes induced by ChABC have important implications for SCI treatment strategies. Plain Language Summary: When the spinal cord is injured, it can cause serious problems with movement and feeling. Scientists are searching for ways to help the body repair itself after such injuries. This study looked at many earlier experiments that used a special substance called ChABC, which helps clean and fix the damaged part of the spine. The researchers reviewed the results of 17 studies on animals. They discovered that when ChABC was given soon after the injury, it stopped large scars from forming and helped protect the healthy parts of the spinal cord. It also allowed new nerves to grow and reconnect, making it easier for the body to heal and work better again. These positive effects were seen whether the treatment was given early or later after the injury. Overall, using ChABC helped the spinal cord recover better and improved nerve repair in animals. Scientists believe that it could one day help people with spinal injuries, but more research is still needed to make sure it is safe and effective for humans.