Recent Advances in the Synthesis and Development of Curcumin, its Combinations and Formulations and Curcumin-like Compounds as Anti-infective Agents.

Infectious diseases are caused by pathogenic microorganisms, such as bacteria, fungi, parasites and viruses. Such diseases mostly develop in tropical and sub-tropical climates and represent major health challenges. The pathogens of these diseases are able to multiply in human hosts, warranting their continual survival. Prevention of these diseases is becoming extremely difficult due to the absence of effective vaccines and their treatment, less effective due to the emergence of resistance by their causative pathogens to existing drugs. Several currently available drugs employ oxidative stress, resulting from the generation of reactive oxygen nitrogen species (RONS), as the mechanism for exerting their pharmacological actions. RONS inhibit endogenous antioxidant enzymes, which ultimately eradicate the microbiota. Curcumin, a redox-active natural product, for centuries, has been used in Asian traditional medicine for the treatment of various diseases. It is known for possessing multiple biological and pharmacological activities. Curcumin has been investigated extensively over the years for its anti-inflammatory, anticancer, antiparasitic, antiviral and antibacterial activities, and no toxicity is associated with the compound. Despite its potency and good safety profile, curcumin is still in clinical trials for the treatment of diseases, such as tuberculosis, acquired immunodeficiency syndrome (AIDS), Crohn's disease, colorectal cancer, and multiple myeloma, among many others, as it is yet to be qualified as a therapeutic agent. This review summarizes events over the last decade, especially regarding the discovery of curcumin, an update of its synthesis, its pathogen specific mechanisms of action, and the pharmacological effects of its derivatives, combinations and formulations as potential antibacterial, antifungal, antiparasitic and antiviral agents for the treatment of various infectious diseases.