Beneficial effects of oral administration of C-Phycocyanin and Phycocyanobilin in rodent models of experimental autoimmune encephalomyelitis

The only three oral treatments currently available for multiple sclerosis (MS) target the relapsing forms of the disease and concerns regarding efficacy, safety and tolerability limit their use. Identifying novel oral disease-modifying therapies for MS, targeting both its inflammatory and neurodegenerative components is still a major goal. The scope of this study was to provide evidence that the oral administration of C-Phycocyanin (C-PC), the main biliprotein of the Spirulina platensis cyanobacteria and its tetrapyrrolic prosthetic group, Phycocyanobilin (PCB), exert ameliorating actions on rodent models of experimental autoimmune encephalomyelitis (EAE). EAE was induced in Lewis rats using the spinal cord encephalitogen from Sprague Dawley rats and in C57BL6 mice with MOG35–55 peptide. Clinical signs, motor function, oxidative stress markers, cytokine levels by ELISA and transmission electron microscopy analysis were assessed. Either prophylactic or early therapeutic administration of C-PC to Lewis rats with EAE, significantly improved clinical signs and restored the motor function of the animals. Furthermore, C-PC positively modulated oxidative stress markers measured in brain homogenate and serum and protected the integrity of cerebral myelin sheaths as shown by transmission electron microscopy analysis. In C57BL/6 mice with EAE, PCB orally improved clinical status of the animals and reduced the expression levels of brain IL-6 and IFN-γ proinflammatory cytokines. These results, for the first time, support the fact that both C-PC and PCB administered orally could potentially improve neuroinflammation, protect from demyelination and axonal loss, which may be translated into an improved quality of life for MS patients.