Medical plants for lung cancer: an overview of current knowledge

Lung cancer is an uncontrolled cell growth in lung tissue, with changes in the cellular, epigenetic and genetic alterations, oncogenes activation and clonal evolution of malignant cells. The most critical risk factor for lung cancer is cigarette smoking (80-85%). Other reasons for lung cancer (15-20%) include genetic factors, exposure to secondhand smoke, air pollution, radiation, hazardous gases and foreign chemical agents. The most widely used strategies in lung cancer treatment are chemotherapy, radiotherapy and surgery. However, there are various adverse effects, such as significant toxicity, limited efficiency and multidrug resistance. Plants and plant-derived products have proven to have a role in lung cancer therapy and prevention through sensitizing conventional factors, extending patient survival time, avoiding adverse effects of chemotherapy, promoting physiological improvement and ameliorating quality of life in pulmonary malignancy cases. For this review article, we searched Web of Science, EBSCO, Scopus, PubMed/Medline, DOAJ (Directory of Open Access Journals), Embase, and Google Scholar, using various keywords. There are several natural product molecules with anticancer properties through many molecular mechanisms, including, inducing apoptosis, inhibition of angiogenesis and metastasis, reversion of multidrug resistance and also targeting reactive oxygen species signaling. Some phytochemical compounds are discussed as anticancer agents for lung cancer.