Clinical Applications of Non-Antimicrobial Actions of Tetracyclines in Inflammatory Diseases

Tetracyclines are the second most common antibiotic family in the human and veterinary medicine usage, worldwide. These groups of drugs originally developed as antibiotics with antibacterial activity are able to exert biological effects different from their antimicrobial action. The actions occur by multiple mechanisms and include inflammatory cytokine regulation, antioxidation, inhibition of leucocyte chemostasis and activation. Several studies have reported antiinflammatory and anti-apoptopic effects of tetracyclines with neuroprotection. This review summarizes the available data supporting the non-antimicrobial actions of tetracyclines linked to reactive oxygen species. We extend our discussion to the potential applications of the drugs for combining with other pharmacological molecules for neurodegenerative diseases such as Parkinson's disease, Huntington's disease, Alzheimer's disease, multiple sclerosis and other linked to reactive oxygen species. Participation of tetracyclines in inhibition of matrix metalloproteinase, scavenging of reactive oxygen species and their anti-inflammatory and anti-apoptopic effects as examples of beneficial effects are presented. Particular attention is focused on the reactive oxygen species and reactive nitrogen species linked with pathogenesis of some human diseases as overproduction of these species results in oxidative stress leading to damage of cell structures.