Naturally Available Extracts Inhibiting Cancer Progression: A Systematic Review

Aim. This systematic review is aimed at evaluating the literature on the efficacy of naturally available extracts that inhibit cancer. Methods. A literature search was performed to strengthening the reporting of observational studies in epidemiology analysis. Approximately 3000 research articles were initially selected. Of these articles, 200 were included, and 2800 were excluded. On further scrutiny, 150 of the 200 studies were reviews, seminars, and presentations, and 50 were original study articles. Among these articles, 20 studies were selected for the systematic review. Results. The predominant molecular pathways followed by natural extracts were nuclear factor kappa B ligand, suppression of the protein kinase B-Akt/P13K pathway (an intracellular signaling pathway important in regulating cell cycle), vascular endothelial growth factor downregulation, and tumor protein-P53 tumor suppressor upregulation. Conclusions. It is evident that natural extracts have the ability to inhibit cancer progression. Continued research in this field could facilitate the use of natural extracts with currently available anticancer agents.