ABSTRACT
The large-scale production and rampant use of antibiotics have led to higher concentrations of antibiotics in the environment, a condition known as “antibiotic pollution”. With a negligible number of antibiotics in clinical trials, the future of mankind is at stake and urgent efforts are needed to develop novel anti-infective therapies. Antimicrobial peptides (AMPs) are evolutionally conserved, gene-encoded entities that are a part of the nonspecific part of the innate immune system inherent in most lifeforms and have a major role to play in the host defense against pathogens. Among the AMPs, thionins have occupied a place of prominence and have carved a special niche for themselves as antimicrobial agents. Thionins, the first AMPs reported from plants, are small (45–47 amino acids long), basic, cysteine-rich AMPs having three to four disulfide bonds. Thionins display significant activity against several organisms, including yeasts, fungi, protozoans and insect larvae. These amphipathic polypeptides, on account of their broad antimicrobial efficacy, also seem to be promising drug candidates for development of anti-infective drugs that are essential in combating emerging infections and diseases.
