Antimicrobial peptides: A small molecule for sustainable healthcare applications

Antimicrobial peptides (AMPs) are compounds that inhibit the growth of bacterial pathogens by preventing microbial colonization in the host. AMPs are usually found in animals, humans, and plants. In particular, AMPs of human origin are released by cells of the immune system in response to microbial infections. Studies have shown that AMPs target virulence proteins of bacterial strains and inhibit the colonization of host tissues. However, over the past few decades, the emergence of drug-resistant pathogenic strains has led to sources for AMPs from green sources such as tropical plants. Such plant-based AMPs (pAMPs) were proven to exhibit antimicrobial activity against several gram-positive, gram-negative, and fungal pathogens. Several studies have demonstrated the presence of pAMPs such as thionins, defensins, snakins, lipid transfer peptides, and knottin-like peptides from a wide range of plant sources. For instance, pAMP such as defensins (CtDef1) from the plant species Clitoria ternatea were proven to inhibit Bacillus subtilis. In addition, such pAMPs are sustainable as they are extracted from green sources such as plants. Therefore, pAMP can potentially combat the threat of drug resistance in pathogenic strains. This review highlights the mechanism of the plant AMPs and their role in killing bacterial cells. In addition, this article also critically evaluates the studies conducted using pAMP conjugated with fluorescent markers to identify the subcellular targets. Overall, this article emphasizes the potential of plant AMPs in mitigating drug resistance.