Molecular responses of cancers by natural products: Modifications of autophagy revealed by literature analysis

Although numerous bibliometric studies have examined various aspects of cancer research, the landscape of scientific studies focusing on natural products in cancer research has not been characterized. Using the Web of Science Core Collection online database, we identify and analyze scientific articles on natural products in cancer-related research. English is the language of publication for 99% of articles. In general, annual citation count of an article increases quickly after publication, reaches a plateau in the second year, stays in this plateau for 10 yr, and then begins to fall. The five most contributing journal categories are medicinal chemistry, contributing the most at 1890 articles (24% of 8012 articles); oncology (20%, with 1572 articles); pharmacology and pharmacy (19%, with 1557); biochemistry and molecular biology (15%, with 1225); and plant sciences (11%, with 883 articles). The United States and Spain yield a larger number of articles with high average citations, and China has been increasing since 2009. Apoptosis and cytotoxicity are the two most-frequently used keywords. Effects of natural products on autophagy with a relevance to cancer are mentioned in 69 publications. Our literature analysis reveals a dynamically evolving landscape and an increasing volume of research investigations that are focused on the study of natural products in the context of cancer. Curcumin, flavonoids, and resveratrol are the most-frequently mentioned natural products. Cancer of the breast, prostate, and colon are the most-frequently mentioned cancers.