oa Editorial [Hot Topic (2): Current Advances in Cancer Prevention and Treatment by Natural Products (Guest Editor: Anupam Bishayee, M.Pharm., Ph.D.)]

Natural products, obtained from plant, animal, marine as well as mineral sources, have been used by mankind since antiquity for the prevention and amelioration of a multitude of illnesses. Cancer remains one of the most serious challenges in health care in the modern world and the use of natural products has gained widespread recognition as an important therapeutic strategy. It was a few decades earlier that the National Cancer Institute, recognizing the importance of natural products as anticancer tools, led a worldwide search to discover novel anticancer agents obtained from natural sources. This initiative led to the discovery of several natural products with potent antineoplastic properties. The prominent chemotherapeutic agents currently used in chemotherapeutic practice include taxol, obtained from the Pacific yew (Taxus brevifolia) as well as vincristine and vinblastine, both alkaloids, found present in the Madagascar periwinkle (Vinca rosea). Chemoprevention by consumption of phytoconstituents of dietary origin present in several fruits, vegetables, nuts and spices, has been proposed as an important approach in the fight against cancer. It has indeed given me great pleasure, at the invitation of Dr. Zeno Foldes-Papp, Editor-in-Chief, Current Pharmaceutical Biotechnology, to invite eminent scientists and researchers all over the world to contribute to this special issue entitled “Current Advances in Cancer Prevention and Treatment by Natural Products”. In this journal issue investigators active in the field of studying the potential chemopreventive and therapeutic properties of natural product constituents and their applications highlight recent developments in the field as well as provide insight in what the future holds for the use of these natural compounds in man's battle against cancer. The first article by my esteemed colleague Dr. Geldenhuys highlights the role of natural products, such as dietary phytochemicals curcumin, caffeine and resveratrol, as inspiration for the design and development of novel compounds with better therapeutic and bioavailability profiles and also provide scaffolds to aid drug discovery. The next article by Drs. Priyadarshini and Nagini provide an overarching perspective in the use of phytochemicals of dietary origin as chemopreventive agents against cancer. In this article, the authors highlights several aspects of dietary chemoprevention including the signaling pathways involved in the mechanisms of action of these compounds as well as their important antioxidant, anti-inflammatory and pro-apoptotic properties. Dr. Ulrich and colleagues then comment on an important area in cancer treatment where natural products are finding use. In their contribution, they highlight the use of two important dietary phytoconstituents, namely resveratrol, a stilbene molecule present in grapes, peanuts as well as red wine, as well as sulforaphane, a naturally occurring isothiocyanate, obtained from cruciferous vegatables, such as cabbage and cauliflower, as adjuncts in obtaining higher efficacy and reducing the toxicity of chemo- and radiotherapy. Dr. Rao, in the next article, reviews the current status and future prospects that entail the use of triterpinoid compounds, such as cucurbitacin, lupeol and oleanolic acid, as potential chemopreventive and therapeutic agents against human cancers. In the next section, we present several articles dedicated to the use of dietary phytochemicals both as chemopreventive as well as therapeutic agents. In view of the SELECT studies, the two articles focus on the significant potential of both selenium and vitamin E in the fight against cancer. Dr. Wada presents a detailed review on the significant role of vitamin E and related tocopherol compounds as anticancer agents. This review is followed by another interesting article authored by Dr. Hu and colleagues which highlights the potential significance of selenium rich-compounds, obtained from natural organic and inorganic sources as well those of synthetic origin, in the chemoprevention of colorectal cancers. Dr. Dhar then reviews the chemopreventive and therapeutic properties of crocetin, a diterpene, found in the spice saffron (Crocus sativus). The importance of β- carotene and related orange-yellow carotenoid compounds is reviewed by my esteemed mentor, Dr. Chatterjee. In this review, along with his colleagues, Dr. Chatterjee reviews a wide spectrum of aspects, such as biological mechanisms, epidemiological studies, clinical data, and future implications in the use of carotenoids as dietary agents to lower cancer risk. Dietary polyphenols, obtained from various sources, represent robust chemopreventive agents and form a cornerstone in the development of the strategy for cancer chemoprevention. The next article by Dr. Gupta and colleagues highlights the chemopreventive and chemotherapeutic significance of polyphenols, such as catechins obtained from the leaves of the plant Camellia sinensis, used in the preparation of tea, a popular beverage consumed worldwide. Dr. Brown and her colleagues reflect upon the molecular mechanisms which bestow anti-proliferative properties to several phytochemicals, such as flavonoids and anthocyanins to name a few, obtained from popular berries, such as blackberries, blueberries, cranberries and raspberries as well as black currants.....