Essay: Development of MS

Notwithstanding the multiannual study of MS, it still remains an urgent problem in neurology and neuroimmunology. Specific factors causing the disease have yet to be traced. Development of MS is likely to be attributable to several factors, among which are infectious diseases, as well as genetic and environmental factors. It is well known that MS pathogenesis encompasses a complex of immunogenic reactions and is induced by activation of antigenic CNS structures, the final target of which are the myeline basic protein (MBP) and myeline oligodendrocyte glycoprotein (MOG). Briefly, activation of T-lymphocytes on the periphery is thought to be the first stage in the development of the disease. In the next phase the activated T-lymphocytes pass the blood brain barrier and penetrate the CNS (4). As a reaction to inflammatory processes, permeability of the blood brain barrier decreases, the nerve tissue is distended, macromolecules deposition from the blood and enclaves develop. This comes with activated microglia and astroglia and the resulting secretion of cytokines. In consequence, monocytes and T- and B-lymphocytes flock to the focus of inflammation, secreting various active compounds that act as main factors affecting oligodendrocytes and myelin (5). The role of neurons in the progression of the disease has recently become the focus of scientific research. This is because reflecting on myelin damage within the immunogenic light has proved insufficient in determining the mechanism of the pathology. Hence, metabolic changes in neurons have attracted particular attention as they lead to neurodegeneration (2). It has been found that demyelination and inflammation in the CNS are preceded by certain changes in the neural cells, particularly by intensified nitrification and oxidative stress in mitochondria, which leads to declined mitochondrial potential and neuron apoptosis (4). Four main types of MS have been distinguished: relapsing-remitting, primary progressive, secondary progressive, progressive-relapsing, the first and the second of which are considered to be autoimmune. Meanwhile, the third and the fourth types are thought to be primarily induced by metabolic changes in CNS neurons (6). Therefore, MS may be seen as a multifactor disease covering both an activated immune system and progressing neurodegenerative processes. However, which of these two have a priority in stimulating MS remains to be discovered. Contemporary MS treatment envisages three major directions: a) complication control; b) prevention using medication, which will affect progression of the disease; and c) symptomatic treatment (6). Forms of treatment vary by the type of the disease, but corticosteroids, such as dexamethasone and methylprednisolone, and adrenocorticotrophic hormone (ACTH) still remain the most common drug for treatment. They alleviate inflammatory processes in the brain and spinal cord and reduce the number of antibodies in the blood. Preventative medication which changes the flow of the disease is particularly effective. It inhibits its progression and significantly reduces the number of fits. Such heightened interest to MS has been conditioned by two main causes. On the one hand, the number of patients is rising, mainly comprising the young and the middle-aged. On the other hand lies the difficulty in its treatment. Notwithstanding its high economic cost, therapy rarely results in a positive outcome. This is why treatment using extracts enriched by flavonoids can be of significant potential as they can both prevent and modulate neurodegenerative diseases and be used as a therapeutic. Flavonoids are phytogenous metabolites actively used to treat various diseases. They activate the antioxidant system and protect cells from free radicals (7-10). They are also applied as anti-carcinogens (11-13). As lowmolecular compounds, flavonoids find it easy to penetrate the blood brain barrier and are also used for prevention of various neurodegenerative diseases (14). Remarkably enough, flavonoids serve as key ingredients of all kinds of new-generation medication used to treat neurodegenerative maladies. Their regular administration is also linked with a reduced risk of such diseases arising. In the CNS these compounds interact with the components of signal pathways, augmenting their neuroprotective properties (3, 15-17). Apart from an immediate impact on neural cells, flavonoids are also capable of easing neuro-inflammatory processes in the CNS under MS and inhibit demyelination (5, 18-22).