Matrine protects oligodendrocytes by inhibiting their apoptosis and enhancing mitochondrial autophagy

Stressed oligodendrocytes (OLGs) activate microglia to produce an inflammatory response, and the impairment of mitochondria further aggravates OLG damage, which is the earliest pathological change in multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system. Matrine (MAT), a tetracyclic quinolizine alkaloid derived from the herb radix sophorae flavescentis, has been shown to effectively ameliorate clinical signs of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, the mechanisms underlying the effect of MAT treatment need to be further studied. In the present study, we show that MAT effectively suppressed ongoing EAE, and significantly reduced the expression of caspase-3 and alpha B-crystallin in OLGs, therefore lessen OLG apoptosis, microglial activation and inflammatory factors secretion. MAT treatment also reduced the content of cytochrome c and malondialdehyde, an oxidative stress marker, in the central nervous system. In contrast, the levels of autophagy-related proteins Beclinl, microtubule-associated protein I light chain 3 and glutathione peroxidase was upregulated, hence enhancing mitochondrial autophagy and alleviating the imbalance of the oxidation/antioxidation system caused by mitochondrial damage. Our research indicates that MAT is effective in treating EAE, at least in part, by protecting OLGs through inhibiting their apoptosis and enhancing mitochondrial autophagy.