Possible Biological and Clinical Applications of Phenothiazines

Phenothiazines have been used in many areas of medicine, mainly in psychopharmacology. These compounds are able to effectively inhibit dopamine, histamine, serotonin, acetylcholine, and α-adrenergic receptors; thus, their effect and side-effect profiles are extremely diverse. Besides their antipsychotic activity, phenothiazines have a significant antimicrobial effect as well, since they can enhance the bactericidal function of macrophages and inhibit efflux pumps. They are also able to eliminate bacterial resistance plasmids and destroy bacteria by their membrane-destabilizing effect. Their antiviral, antiprotozoal, antifungal, and antiprion activities have also been described. Phenothiazines have also been proven to destroy cancer cells and sensitize them to chemotherapy. Anti-angiogenesis and anticancer stem cell activities have also been reported, and they might be applied as adjuvants in the treatment of infections and tumors in the future. Finally, phenothiazines can also be effective in the treatment of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease.