Polypeptide-k” as phytoinsulin: How much and how far

Abstract

Diabetes mellitus (DM) is a metabolic disorder characterized by high blood glucose levels, occurs due to insulin resistance or insulin deficiency. In 2015, 415 million people worldwide suffered from DM. There have been number of antidiabetic drugs and recombinant DNA insulin used for diabetes; however, these have certain limitations in terms of side effects and cost. Need of society and efforts of scientists led to discovery of phytoinsulins. A plethora of literature is available with reports of the presence of insulin-like hormones in plants. These include bacteria (Escherichia coli), protozoa (Tetrahymena pyriformis), fungi (Neurospora crassa and Aspergillus fumigatus), and plant (Momordica charantia, Canavalia ensiformis, Vigna unguiculata, Bauhinia variegate, and Spirulina maxima) that are used to treat DM. This theory of presence of phytoinsulins has been further strengthened by presence proteins associated with insulin signaling pathways in plants. Polypeptide-k (PPK), an isolated peptide from M. charantia has shown its therapeutic potential as antidiabetic drug. It has structural similarity with insulin moreover, safety and efficacy of PPK as antidiabetic drug has been proven through various preclinical and clinical studies. Phytoinsulins like PPK have potential to replace costly recombinant DNA insulin. However, more clinical studies are required to establish PPK and other phytoinsulins to establish as first-line therapy in the management of diabetes.