Bioactivity Based Proteomics of Selected Medicinal Plants for Drug Discovery

Abstract

Emergence of multidrug resistance, side effects and heavy cost of synthetic medicine make it a challenge to explore new drugs having no such problems. To overcome these problems, there is a need to explore natural resources like plants. Medicinal plants are most abundant resources and their bioactive properties and possibly undiscovered novel modes of actions can be a solution to control the multidrug resistance. This study is also a part of this big project in which plants are explored to find novel peptides/protein based drugs by mass spectrometric approaches. Eight medicinal plants were screened on the basis of their antibacterial activities. Eruca sativa and Linum usitatissimum showed highest antibacterial potential and selected for proteomic studies. Before moving to proteomics, these two selected plant species were evaluated further for other biological activities viz antifungal, antioxidant, thrombolytic and hemolytic. Significant results proved that the biological potential was due to the presence of bioactive peptides/proteins, as the activities were almost abolished after proteinase K treatment. By bottom-up proteomics, 22 differentially expressed proteins from E. sativa were identified in this study having a good range of biological functions including antimicrobial, antiaphid, antigenic and cardio-protective. Eighteen constitutively expressed bioactive peptides (belong to 7 different classes of AMPs) were identified from L. usitatissimum by top-down proteomics. Literature reveals that these peptides have a good potential against life threatening diseases including antimicrobial, anti-HIV, anti-angiogenic, anticancer, uterotonic and insecticidal potentials. These peptides/proteins may have potential to be used in drug development after further structural and functional characterization.