Effects of Oenothera biennis L. and Hypericum perforatum L. extracts on some central nervous system myelin proteins, brain histopathology and oxidative stress in mice with experimental autoimmune encephalomyelitis.

We investigated the effects of Oenothera biennis L. and Hypericum perforatum L. extracts on brain tissue histopathology, myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) in mice with experimental autoimmune encephalomyelitis (EAE). Forty-seven C57BL/6J mice were divided into the following groups: multiple sclerosis (MS), control (healthy mice), MS + H. perforatum treated (MS + HP), MS + O. biennis treated (MS + OB). All groups except the control group were immunized by EAE methods. Two weeks after the immunization, the mice in the MS + HP group were fed normal food containing 18 - 21 g/kg H. perforatum extract, the mice in MS + OB group were fed normal food containing 18 - 21 g/kg O. biennis extract, and the mice in control and MS groups were fed normal food for six weeks. Brain tissue samples were collected from all mice for histopathological and biochemical analysis. Clinical signs of the disease were scored using functional systems scores (FSS) daily. The H. perforatum and O. biennis extracts ameliorated the increased brain tissue MOG and MBP values for animals with MS. H. perforatum and O. biennis extract decreased the TOS and OSI values for brain tissue and increased TAS levels in brain tissue of animals with MS. In addition, H. perforatum and O. biennis extracts decreased the clinical signs at the end of the experiment compared to the beginning of extract administration. We found that myelin was lost in MS group vs. control group. H. perforatum and O. biennis extract treatments decreased the amount of myelin loss in the MS + HP and MS + OB groups. We also observed amyloid deposition on vascular walls, in the cytoplasm of the neurons and in the intercellular space in the MS group. O. biennis and H. perforatum treated groups exhibited neither abnormal amyloid deposition nor obvious cell infiltration. The beneficial effects of O. biennis and H. perforatum for attenuating myelin loss and amyloid deposition suggest their therapeutic utility for treatment of MS.

St. John's wort and its component hyperforin alleviate experimental autoimmune encephalomyelitis through expansion of regulatory T-cells.

Multiple sclerosis (MS) is a central nervous system disorder mainly characterized by inflammation, demyelination and axonal injury. Anti-inflammatory agents can be used to ameliorate the disease process. Hypericum perforatum L or St. John's wort is widely used as an anti-depressant and anti-inflammatory remedy in traditional and herbal medicine. Based on St. John's wort properties, the therapeutic potentials of an H. perforatum extract (HPE) and a single component, hyperforin were evaluated for effectiveness against MOG35-55-induced experimental autoimmune encephalomyelitis (EAE), an animal model for human multiple sclerosis. Female C57BL/6 mice were immunized with specific antigen MOG35-55 and then administered different doses of hyperforin or HPE post-immunization. Clinical symptoms/other relevant parameters were assessed daily. Histological analysis of the spinal cord was performed. T-cell proliferative activity was also evaluated using a BrdU assay. The effect of hyperforin on regulatory T-cells (Treg cells) was assessed using flow cytometry. The results indicate hyperforin and HPE reduced the incidence and severity of EAE, an outcome that closely correlated with an inhibition of pathological features (leukocyte infiltration and demyelination) and antigen-specific T-cell proliferation. The study also showed that hyperforin caused increased Treg cell levels in the spleen. These results indicated that hyperforin and HPE could attenuate EAE autoimmune responses by inhibiting immune cell infiltration and expansion of Treg cell and could eventually be considered as a potential candidate for use in the treatment of MS.