Morphine acts via TLR4 resulting in neuroinflammation and immunosuppression

Abstract

Millions of people suffer globally from disorders caused by narcotic substances. Drug addiction leads to the destruction of an individual's life and risk to public safety. Morphine is the prime alkaloid well-known as the mother opiate and has many implications for the human body, specifically for the immune system. It down-regulates all the arms of the immune system and reduces its efficiency in combating different pathogenic molecules. It also implicates human physiology and deviates from homeostasis. The morphine-like drugs alter the immune system by binding to the mu receptor. This binding results in impaired clearance of pathogens from the body. Morphine produces organ-specific effects; in the brain, it mediates neuroinflammation that is responsible for morphine tolerance and addiction and causes anti-inflammatory effects in the peripheral organs that are responsible for immunosuppression, leading to opportunistic infections. There is huge complexity in understanding the effects of morphine in the biological system. Therefore, in this paper, we will discuss the dual roles of morphine in the brain and peripheral organs and the mechanisms.