Effects Of Ethanol on the Structure and Function of the BBB and Their Roles in Central Nervous System Diseases

The blood-brain barrier (BBB) plays a vital role in maintaining brain homeostasis, as its proper function and structural integrity are essential. Communication between endothelial cells and nearby perivascular cells, which include pericytes, astrocytes, microglia, and oligodendrocytes, is key to the overall structure and function of the BBB. When ethanol is consumed, it raises the permeability of the BBB, leading to significant damage that can adversely affect brain health. This article reviews how ethanol interacts with the body, detailing the various mechanisms through which it alters the BBB's structure and function. We particularly highlight how ethanol damages endothelial cells, activates astrocytes and microglia, disrupts the differentiation and survival of oligodendrocyte precursor cells (OPCs), triggers neuroimmune responses, inhibits glucose transport, modifies blood pressure, and increases blood flow. Moreover, we examine how different levels of ethanol consumption influence the risk of developing conditions like Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. Interestingly, moderate alcohol intake may lower the odds of these diseases, while excessive drinking can heighten the risk. The effects of ethanol exposure on BBB permeability can also vary due to factors like sex, age, and genetics. Research suggests that estrogen is important for preserving the integrity of the BBB and protecting against neural damage, whereas high levels of ethanol intake may worsen BBB impairment, especially in individuals with the ApoE4 genotype. In summary, this article focuses on the mechanisms by which ethanol impacts the BBB, with the goal of offering insights that could assist in preventing and treating central nervous system diseases, particularly AD.