Ibudilast (IBD) is a new drug that has been released as treatment for multiple sclerosis (MS). Retinoic acid (RA), a metabolite of vitamin A, is known for its pro-regenerative and anti-inflammatory properties, therefore, it has been suggested as a supplementary treatment for MS. The objective of this study is to investigate the therapeutic effects of RA and IBD against cuprizone (CPZ) induced mouse models. Seventy-two Swiss Albino male Mice (SWR/J) were divided into two main groups control (n = 18); normal chow and CPZ (n = 54); 0.25% of CPZ mixed into chow at demyelination stage (first 5 weeks). The following 4 weeks included two stages of remyelination: early remyelination (2 weeks after CPZ discontinuation) and late remyelination (week 9). In the early stage of remyelination, the CPZ group was divided into four subgroups beside daily treatment intraperitoneal injections CPZ (+ve control- no treatment), RA (20 mg/kg), IBD (10 mg/kg), and RA + IBD, with (n = 12/group), while the control group had 12 mice. At the end of each stage 6 mice/ group were sacrificed. Mice response to different treatments was assessed using several locomotor and cognitive behavior tests including open field test, rotarod test, grip strength test, novel object recognition test (NORT) and Y-maze test. The expression levels of several genes MS associated genes Tumer Necrosis Factor- Alpha (TNF- α), Cyclooxygenase-2 (COX-2), Nerve Growth Factor (NGF), Signal transducer and activator of transcription 3 (STAT-3) and Nuclear factor kappa-light-chain-enhancer of activated b-cell (NFKB-P105) in the brain of mice were measured using quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) analysis. The results demonstrated that RA supplementation helped in alleviating the symptoms of MS induced mice with or without using IBD treatment. This was indicated as an improvement in locomotor activity, motor coordination and muscular strength as well as improving the cognition and memory functions. The mRNA expression pattern of various MS associated genes indicated that the treatments effectively mitigated the detrimental effects of CPZ in mouse brain. The findings of this study indicate that RA supplements could be effectively unitized as adjuvant therapy alongside with IBD for MS treatment.

Background/Objectives: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by inflammation, demyelination, and axonal loss. Despite available therapies, there is currently no effective cure for MS. Ibudilast (IBD), a phosphodiesterase inhibitor, and 6-shogaol (SH), a bioactive compound from ginger, have independently shown therapeutic potential in MS models. This study aimed to evaluate the therapeutic efficacy of combining SH and IBD in modulating neuroinflammation and improving functional recovery in a cuprizone (CPZ) mouse model of MS. Methods: Male SWR/J mice were exposed to 0.3% CPZ for 5 weeks to induce demyelination, followed by 4 weeks of spontaneous remyelination after CPZ withdrawal. During remyelination, the CPZ group was subdivided into four groups: no therapy, SH (25 mg/kg), IBD (10 mg/kg), and SH + IBD. Behavioral tests were used to assess locomotion, muscle strength, coordination, and memory. Gene expression of proinflammatory and anti-inflammatory cytokines was analyzed in brain tissue. Results: The combined treatment significantly improved locomotor activity, muscle strength, and memory during remyelination phases while suppressing proinflammatory gene expression and enhancing anti-inflammatory pathways in the brain. Conclusions: SH and IBD combination therapy provides enhanced anti-inflammatory and functional benefits compared with monotherapies, supporting its potential as a promising multi-target therapeutic strategy for improving functional recovery and modulating neuroinflammation during the spontaneous remyelination phase following CPZ withdrawal.