Abstract
Background & Aim: Cancer is a condition of genetically or environmentally mutated, uncontrollable cell growth that directly affects human morbidity and mortality. Many treatments have been adopted to reduce cancer cell proliferation; however, new mutated developments of some cancer cells have started to show resistance towards current therapies and treatments that cause some drugs to lose their efficacy. Additionally, deleterious side-effects of some hard application methods like radiation therapy, chemotherapy, and surgery are less favorable. Accumulative research effort has revealed that peptides and toxins identified from underutilized natural sources including venomous reptiles, amphibians, insects, arachnids, marine organisms and plants are increasingly being employed in cancer treatment. This demands more peptides / toxins to be identified from underutilized natural sources as an alternative therapeutic approach.
Method & Results: Accumulative research effort has revealed that peptides and toxins identified from underutilized natural sources including venomous reptiles, amphibians, insects, arachnids, marine organisms and plants are increasingly being employed in cancer treatment. Secondary structures / pharmacophore modifications have proven to be an important criterion for raising the efficacy level and anticancer effects. Structure specificity and structural-related cytotoxicity have successfully allowed these peptides to target and cause sufficient damage to malignant cells with minimal cytotoxicity effects towards healthy cells. On top of that, some these pure peptides had adopted multiple anticancer mechanisms and demonstrated collective anticancer effects within a single application. Conclusion: Our review exclusively selected peptides and toxins found identified from various natural sources in combating malignant cells, their selectivity towards specific anticancer mechanisms, and the prospective of conjugated peptide as a single entity for a new therapeutic strategy.Keywords: Cancer, venom, reptiles, amphibians, insects, plants, conjugated peptide, toxin, mechanisms.