Functional Foods for Health Maintenance: Understanding their Role in Cancer Prevention

Worldwide, cancer has become the most life-threatening disease. The current remedial treatment of cancer includes chemotherapy, surgery, immunotherapy, stem cell transplant and hormone therapy. Plants produce secondary metabolites in abundance having medicinal properties used for treating various diseases, such as AIDS, diabetes, cancer, inflammation, fever, diarrhoea and bacterial and fungal infections. Naturally derived components are largely considered by scientists and researchers due to their low toxicity and lesser side effects. Functional foods are the food or food components that provide health benefits beyond basic nutrition. Functional foods simply provide nutrients that help to maintain health, thereby reducing the risk of disease. Various vegetables like Asparagus racemosus, Cocos nucifera, Brassica oleracea var. Botrytis, Zingiber officinale, Atrocarpus heterophyllus, etc., pulses, i.e., Cicer arietinum, Phaseolus vulgaris, Vigna radiate, Vigna mungo, etc., and Spices viz., Ferula asafoetida, Piper nigrum, Elettaria cardamomum, Coriandrum sativum, Nigella sativa and Curcuma longa, are explored for their potential role to fight many diseases and anticancer activity. This review aims to highlight the protective and synergistic role of functional foods in cancer prevention.

Cancer - the name evokes fear and anxiety. Researchers are working tirelessly to bring hope to countless patients by developing prevention and treatment strategies. One approach is dietary modulation - which is documented to reduce the risk of cancer and increase the benefit of anti-cancer therapy. Allium species are a part of the daily diet in most parts of the world. Important members of this genus - chives, garlic, onions, and shallots add flavour and nutrition to food. These are prized for their organosulphur compounds and flavonoid content which are responsible for their diverse pharmacological activities. Traditional and scientific literature shows that dietary intake of Allium species prevents and aids the treatment of different cancers. In this review, based on an extensive search of available databases, the role of Allium species as nutraceuticals for cancer management was examined to ascertain the truth in the popular claims. Preclinical and clinical investigations show that consumption of the Allium members as a part of the diet and also the functional components (e.g., allicin, diallyl disulphide, diallyl trisulphide, ajoene, S-allyl cysteine, S-allyl mercaptocysteine, tuberoside M, onionin A, fisetin, quercetin, etc.) reduce risk of cancer and have significant antitumor activities. These act by varied mechanisms, including inhibition of gene expression, promotion of apoptosis of cancer cells, antiproliferative activity, and anti-oxidant and anti-inflammatory effects. It is emphasised that standardization of Allium products, their efficacy, dosage, safety profiles and interactions should be ascertained to corroborate their use. This article highlights the importance of Allium species for their prophylactic, therapeutic and immune-boosting ability in cancer management.

Globally, cancer is the main cause of mortality and morbidity. Unfortunately, existing medical procedures are not adequate due to a lack of appropriate therapy, adverse health effects, chemoresistance and disease recurrence. In recent years, epidemiological findings have illustrated the connection between the consumption of several phytochemical-enriched foods and nutrients, and the lower risk of different types of cancer. Natural compounds named ‘phytochemicals’, commonly found in fruits, vegetables, and whole grains, have shown convincing beneficial biological effects on human well-beings, including curing different types of cancers. Phytochemicals, which are non-nutritive chemicals present in plants, have come up as modulators of essential cellular signaling pathways exerting proven anti-cancer benefits. Dietary phytochemicals have received major interest in chemoprevention as they are thought to be safe for human use. Chemo-preventive agents restrain the growth of cancer either by impeding DNA damage, which contributes to malignancy or by preventing or restricting the division of premalignant cells through DNA damage. Phytochemicals may prevent carcinogenesis by contributing to cell cycle arrest, autophagy and apoptosis. The bioactive compounds have been reported to reverse adverse epigenetic control, including modifying DNA methylation and histone alteration, modulating the expression of miRNA, inhibiting phase I enzymes, and activation of phase II enzymes, scavenging DNA reactive agents, preventing the excessive proliferation of early, preneoplastic lesions, and suppress other properties of the cancer cells. These have all been a part of indirect yet successful and innovative approaches to cancer treatment utilizing phytochemicals.

Alternative and complementary therapies have been widely used for the treatment of cancer throughout the world. The term ‘Complementary and Alternative’ (CAM) was used by the American Cancer Society and the Union International Centre le Cancer (UICC). Complementary and alternative medicines mean anything which is not conventional; the reasons to adopt these therapies are that it makes use of the procedures used in adjunct to mainstream therapy in order to improve the quality of life. Several evidences were put on trial that support the value of hypnosis for cancer pain and nausea, mind-body therapies, relaxation therapy, massage for anxiety, acupuncture, homeopathy, Ayurveda, chiropractic medicine and osteopathy. The use of unconventional agents, pharmacological and biological agents, diet and nutrition and herbal therapies are amongst some of the most recent advances in alternative cancer therapies. This article reviews the various popular cancer therapies commonly practiced in India and abroad and reveals the scenario of various complementary and alternative cancer therapies.

Cancer is a leading source of illness and mortality around the world. Despite the fact that primary cancer treatment has considerably reduced cancer mortality, the survival rate remains low due to tumour metastasis, a variety of adverse medication responses, and drug resistance. Alternative medicines, particularly herbal medications, have piqued the interest of scientists due to their high efficacy and low toxicity. However, their limited water solubility, low stability, poor absorption, and quick metabolism limit their therapeutic usefulness. Due to these constraints, the focus of phytocancer therapy has switched to tailored drug delivery systems. Nanomedicine, which involves using nanoparticles as drug delivery vehicles to boost the therapeutic benefits of phytochemicals, has a wide range of uses in cancer treatment. Many challenges in drug delivery to cancer cells can be overcome by using nanoparticulate drug carriers, including improved solubility and bioavailability, drug targeting, reducing adverse effects in non-target organs, high efficacy, low drug resistance, and high drug concentration at the tumour site. The present review entails the most recent advancements in anticancer phytodrug delivery employing nanocarrier-based technologies.

Cancer has become a major public health problem and is one of the leading causes of death among humans worldwide. It is characterized by the abnormal proliferation of cells due to failed normal regulatory mechanisms. Oxidative stress plays a crucial role in the pathology of many cancers and is characterized by an imbalance between the production and removal of reactive oxygen species (ROS). Under normal physiological conditions, the intracellular levels of ROS are steadily maintained to prevent cell damage, and detoxification of ROS is facilitated by various non-enzymatic and enzymatic antioxidants. These antioxidants have a widespread application in the prevention of cancer, as many endogenous and exogenous antioxidants can prevent and repair damage caused by disrupted redox status of cells during carcinogenesis. Our body can produce some of the antioxidants, but to obtain the rest of the antioxidants, it relies on external sources, primarily the diet of an individual. Also, there are certain health issues reported with the long-term usage of synthetic antioxidants. Therefore, nowadays, many nutritionists and dieticians suggest consuming food and natural products that are either rich sources of antioxidants or are supplemented with various nature-based antioxidants. This chapter seeks to explain the role of ROS in oncogenesis, understand the dynamics between oxidative damage and the antioxidants, types of antioxidants, natural sources of antioxidants, mode of action of antioxidants and the role of antioxidants in cancer prevention and treatment along with their disputable effects in cancer therapy.

Currently, Breast cancer is the leading cause of cancer mortality in women in U.S. and accounts for a high proportion of new cancer cases in this population. Cancer chemoprevention is a new approach in cancer prevention, in which chemical agents derived from the natural and synthetic source are used in nontoxic concentrations to prevent cancer in normal and/or high-risk populations. To date, numerous cancer preventive agents derived from natural products have been evaluated for their cancer chemopreventive potential. The cancer chemopreventive agents have been isolated from natural sources and/or synthesized and evaluated for their efficacy in a variety of biological assays. As a part of our cancer chemopreventive program spanning more than three decades, we established and utilized a mouse mammary gland organ culture model (MMOC) as a preliminary screening bioassay. This assay was used to evaluate natural-based compounds or their synthetic analogs. Mammary glands respond to growth-promoting hormones, and the physiological differentiation can be reproduced in MMOC. The estrogen and progesterone-dependent mammary ductal lesions (MDL) can be induced in response to a 24-hour exposure to DMBA in MMOC. In order to evaluate the efficacy, we analyze the suppression in the incidence and multiplicity of the lesions. Suppression of the incidence and multiplicity of these lesions by a possible chemopreventive agent can serve as a tool to evaluate the efficacy of potential experimental agents. Using this approach, we have evaluated more than seventy natural product-derived and synthetic chemopreventive agents as a part of the National Cancer Institute-supported projects. It may be worth mentioning that a substantial number of these chemopreventive agents having significant activity in this assay also showed encouraging results in vivo experimental studies. This bioassay not only provided a valuable tool for screening cancer chemopreventive agents for breast cancer prevention but also helped in understanding molecular mechanism(s) of action. In this comprehensive review, we provide a complete list of chemopreventive agents evaluated for efficacy against the development of mammary ductal lesions (MDL) in MMOC, along with the recent developments in in vivo mammary carcinogenesis.

Flavonoids derived from daily dietary source and plant products play a crucial role in the prevention and treatment of various degenerative diseases and cancer. Flavonoids are further subdivided into subclasses such as flavones, flavan-3- ols, flavonols, flavanones, isoflavones and anthocyanidins. There has been a resurgence in the research on flavonoids due to enhancement in the evidence that proves the health benefits of flavonoids. Several preclinical and epidemiological studies revealed that dietary intake of flavonoids may be found helpful in the reduction of risk of tumors like colon, breast, lung, pancreas and prostate. It also acts on the reactive oxygen species, and cellular signal transduction pathways associated with cellular proliferation, angiogenesis and apoptosis. Flavonoids are non-toxic in nature, so intensively studied the broad, vast aspect of their efficacy in biological activities that in turn promotes health benefits and also added to its availability in abundance in our daily diets, for instance, fruits, green leaves, tea, red wine and vegetables. Overall, the exciting data obtained so far elicit that dietary flavonoids have been considered a beneficial cancer preventive approach. This chapter unravels the molecular mechanisms involved in potential cancer preventive efficacy accomplished by the novel biological approach of flavonoids.

Saponins are a large family of biologically active amphipathic glycosides of triterpenoids and steroids. These high molecular weight glycosides consist of an oligosaccharide moiety linked with an aglycone, also known as sapogenin (triterpenoid or steroid). Therefore, structurally saponins are classified into two categories, i.e., triterpenoid saponins and steroidal saponins. They have foaming capacity. They are produced mainly by plants belonging to classes Magnoliopsida and Liliopsida and marine organisms such as starfish, sponges and sea cucumbers. They are non-essential for basic plant metabolism, however, they are produced as secondary metabolites in plants in the presence of biotic and abiotic stresses. Saponins are found in all parts of the plant, including flower, fruits, stem, leaves, etc. Many plants that have medicinal properties or are part of the human diet contain saponins. Their concentration in a plant depends on the type of tissue, physiology, genetic makeup and environment of the concerned plant. They impart a pungent and bitter taste to plants. Various studies across the globe have shown that saponins are chemopreventive, anti-tumor, antiinflammatory, anti-diabetic and anti-obesity in nature. In this chapter, an account of the role of saponins in the prevention and therapy of different health problems, especially cancer in human beings, is presented. This chapter consists of details about the structure, synthesis, sources and biological activities of saponins found in various plant sources used as food. An attempt is also made to compile results from different studies conducted globally to explain the protective and therapeutic effects of saponins.

The mortality rate from various types of cancer is unacceptably high till date. Although, there is a huge advancement in understanding the diverse mechanisms of carcinogenesis and the development of potential drug leads, still there are massive mortality rates. The consumption of various green/yellow vegetables and fruits can help in reducing the risk of cancer. There is a plethora of potential anticancer compounds present in green leafy vegetables, which have been extensively evaluated in cancer. Various anticancer leads include dietary agents in which carotenoids are very significant in combating cancer. Lutein is a yellow carotenoid present in vegetables and fruits. It is the second most prevalent carotenoid in human serum, and its consumption is beneficial for promoting good health. The nutritional value of lutein is very high, and besides this, it is reported to exert antiproliferative potential against various cancers such as cervical, skin, lung, breast and colon cancer. Lutein stimulates various genes involved in T-cell transformations that are activated by mitigens, cytokines and antigens, thereby acting as anti-cancer. Lutein can oxidize and degrade easily due to the presence of conjugated bonds in its isoprenoid polymeric structure. Various food processing techniques can also affect the integrity of lutein. Therefore, there has been development of novel drug delivery systems to enhance the absorption andbioavailability of lutein and also to prevent its chemical degradation. Therefore, it can be concluded that lutein can serve as an effective agent in chemoprevention to fight against various forms of cancer because of its nutritional value.

Cancer is one of the most serious and common human diseases, causing millions of deaths per year worldwide. Currently, the discovery of noble therapeutic agents with a natural origin for cancer treatment is a major challenge. In this context, marine algae with wide species and phytochemical diversity will offer great scope for the discovery of new drugs. Algae with marine origin, including microalgae and macroalgae (seaweeds), constitute more than 90% of oceanic biomass. Marine algae are rich sources of pigments, lipids, carotenoids, omega-3 fatty acids, polysaccharides, vitamins and other fine chemicals. The biomaterials obtained from marine algae are important ingredients in many products, including cosmetics and drugs for treating cancer and other diseases. The in vitro and in vivo evaluations of biomolecules derived from marine algae have shown a vast range of pharmacological properties such as antioxidant, immunostimulatory and antitumor activities to control cancer. In spite of the rich source of various bioactive molecules, the marine algal flora largely remains unexplored for the discovery of active molecules against cancer to date. Hence, this review consolidates the available information on marine algae-derived anticancer molecules to provide baseline information for promoting anticancer research based on biomaterials derived from marine algae.

Every year, millions of people around the world lose their lives to different types of cancer, mostly in developing countries. The foremost challenge for the human race in to fight against cancer is its early detection, followed by the appropriate treatment. Currently, one of the most promising and dynamic strategies for early cancer diagnostics as well as for therapeutics, is the use of cancer biomarkers. Generally, biomarkers represent changes in the constituents or composition of cells, tissues, or body fluids, offering a means for comparable classification of diseases as well as the risk factor involved, and thereby providing information about the underlying pathogenesis of the disease. Similarly, a cancer biomarker (CB) is defined as a ‘molecular signature’ that can potentially provide valid information regarding staging as well as the mechanisms underlying the origin of cancer. Cancer biomarkers (CB) are biomolecules synthesized either by the cancer cells or by other cells of the body in response to cancer. Every cell type has its distinctive molecular signature and recognizable features, such as levels or activities of the myriad of genes, proteins, or other molecular characteristics; therefore, cancer biomarkers can facilitate the molecular definition of cancer. Endoscopy, X-rays, magnetic resonance imaging, computed tomography, invasive tissue biopsies, etc., are the traditional cancer diagnostic methods. However, the use of biomarkers as cancer screening tools have several advantages over these traditional approaches. The emergence of “omics” technologies, like metabolomics, genomics, epigenomics, proteomics, etc., has led to an increase in the number of potentially investigated biomarkers, such as DNA, RNA, miRNA, or other protein biomolecules. In this chapter, we have summarized the importance of biomarkers as powerful and dynamic tools for the early diagnosis of various types of cancers, the phases in the biomarker discovery, the criteria for the selection of biomarkers, the advantages of their preference over traditional methods, various categories of cancer biomarkers, examples of cancer biomarkers currently in use and the future prospectives.

Cancer remains one of the leading causes of death worldwide. Cancer management has been a daunting task for both health professionals and patients throughout the journey. Screening of cancer at the right time/stage remains the most critical part of the riddle. Certain molecules that characterize cancer, known as ‘biomarkers,’ come out to be the most useful in this journey. The National Institute of Health defines a biomarker as “a characteristic used to measure and evaluate objectively normal biological processes, pathogenic processes, or pharmacological responses to a therapeutic intervention”. These have proven to be often easily available agents employing minimally invasive methods. Biomarkers have played crucial roles in screening, asymptomatic and early-stage detection, monitoring of the treatment therapy and eventual follow-up to check upon a probable re-lapse or metastasis. A cancer biomarker can be any of the biomolecules such as protein, DNA, RNA, proteoglycans, immunological compounds, salivary biomarkers and endogenous peptides. With the refinement in high-throughput techniques, the list of the types of biomolecules and the number of potential biomarkers is only increasing, with volatile organic compounds from the breath (breath biopsy) adding to the list. In this chapter, we shall put effort into reviewing this otherwise very vast topic. The chapter will outline various types of biomarkers, the journey so far with clinically approved cancer biomarkers, the challenges being faced, and conclude with future perspectives.

In spite of the existence of many chronic diseases, cancer is still one of the major distresses for public health and is also the second largest major concern of death. The data collected from the last 50 years of research showed that very few cancers are curable, and the fear factor related to this disease is still unaltered. Victorious bench-tobedside transformation of basic methodical findings about cancer into therapeutic involvements for patients relies on the appropriate selection of animal experimental models. Animal models play an important role in studying the genetics and biology of human cancers as well as the preclinical examination of various cancer therapeutics and cancer prevention. In this chapter, we will review the imperative animal models such as spontaneous tumour models, chemically induced tumour models, radiationinduced tumour models, etc., along with other animal models, such as porcine, canines, etc., used for immuno-oncological research. In addition, the role of transgenic animals in cancer research will also be discussed.

Breast and colon cancer represent the leading causes of mortality in developed countries. The treatment options for these organ site cancers differ depending on the status of hormone/growth factor receptors in molecular subtypes that exhibit altered expression of oncogenes/tumor suppressor genes and growth factormediated molecular pathways. Conventional cytotoxic chemo-endocrine therapy traditionally includes the use of anthracyclin, taxol, cisplatin, anti-estrogens, antifolates and DNA anti-metabolites. Additionally, the use of molecular pathway-specific small molecule inhibitors represents evidence-based targeted therapy. Long-term conventional or targeted therapy using pharmacological agents is frequently associated with systemic toxicity, acquired tumor resistance and the emergence of drug-resistant cancer stem cells. These limitations are associated with the progression of the therapyresistant disease.

Natural products such as dietary phytochemicals, their respective bioactive agents, botanicals, nutraceuticals and nutritional herbs are widely used in complementary and alternative medicine in women for estrogen-related issues, osteoporosis and breast diseases. Unlike conventional or targeted chemo-endocrine therapeutics, natural products, mainly due to their low systemic toxicity, may not lead to acquired tumor resistance and therefore, represent testable alternatives against therapy-resistant cancer.

These aspects emphasize a need to develop reliable experimental approaches, and specific and sensitive biomarkers that facilitate the identification of effective testable alternatives against therapy-resistant cancer.

Models for drug-resistant stem cells have been developed and characterized from the parental breast and colon carcinoma-derived cell lines, as well as from the cell lines derived from genetically predisposed colon cancer models. These stem cell models are characterized by the quantifiable expression status of select stem cell-specific cellular and molecular markers.

Mechanistically distinct natural products have documented growth-inhibitory effects on parental cell lines. Some of these agents also exhibit stem cell targeted growth inhibitory efficacy.

Recognizing clinical evidence for the role of estrogens in breast and colon cancer, future investigations include the development of tumor organoid models of therapyresistant breast and colon cancer from female patient-derived xenografts. These investigations support a scientifically robust rationale to provide clinical translatability for patient-derived preclinical data.

This chapter summarizes the evidence relevant to experimental models systems, natural products and efficacy of lead compounds as stem cell-targeted testable alternatives against breast and colon cancer. Collectively, discussed evidence and its clinical relevance support the hypothesis that natural products may benefit patients that are diagnosed for therapy resistant cancers.

Cancer is a large group of diseases that affect the human body at all ages and causes death worldwide. Important progresses have been made in early diagnosis, prevention measures and treatment. Widespread use of secondary metabolites derived from plants has been made for the production of various effective medicines. Various natural bioactive compounds derived from medicinal plants are used as anticancer mediators to remediate cancer syndrome, but they have toxicity and side effects, and hence there is a need to explore more plant-derived cytotoxic chemical agents. Consequently, an effort has been made to evaluate various in vitro and in vivo methods that are used for assessing the efficiency of the anticancer efficacy of natural bioactive compounds derived from medicinal plants. Anticancer secondary metabolites derived from plants are efficient candidates for in vivo and in vitro anticancer activity. This chapter provides detailed information on different plant explants and extracts and various methods used to evaluate anticancer activity.

The growth of functional foods has gotten a lot of attention as people become more aware of the relationship between nutrition and human health. Several problems are identified, including discovering beneficial phytochemicals, establishing acceptable consumption levels, and producing suitable food delivery matrices and product compositions. Many nanotechnology-derived processes and materials have the potential to provide innovative solutions in many of those foreparts. Nanotechnology works with materials on the atomic and molecular levels to create structures smaller than 100 nanometers in one dimension. Food nanotechnology could be a comparatively recent area that has opened up an entire world of new applications in the food industry. The applications comprise better taste, color, flavor, texture, and consistency of foodstuffs, the bioavailability of nutraceuticals, increased absorption and health supplements, food antimicrobial developments, food packaging materials with better quality, mechanical barrier, and antimicrobial properties, nano-sensors for traceability and observing the condition of food during transport and storage, encapsulation of food constituents or additives. This chapter briefly reviews the role of nanotechnology in functional foods and its applications, and food safety, regulation, and challenges are discussed.

Alzheimer's disease (AD) is a neurological illness that causes a person's memory to deteriorate over time, as well as facing difficulties speaking and performing daily tasks. Alzheimer's disease affects around 42 million people worldwide, and this number is expected to quadruple by 2030. A nutraceutical is a bioactive component of human nutrition that is ready to be employed for disease prevention or therapy. The market for nutraceuticals has risen in the recent decade as public awareness of these compounds has grown, as has their utility in the prevention and treatment of a variety of ailments. Antioxidant-rich diets have been found to protect humans from degenerative diseases, such as cancer, diabetes and cardiovascular disease. Plant foods, such as vegetables, fruits, grains, spices, and legumes, have been shown to play important roles in the prevention and treatment of a wide range of chronic diseases by altering many metabolic pathways. Bioactive agents are extra from the functional food and are nutritional elements found naturally in plants that have the potential to have a biological effect. Now, scientists and nutritionists say that the link between nutrition and disease is a relatively recent discovery. The importance of functional foods in the treatment of chronic and neurodegenerative disorders, with a focus on AD, will be highlighted in this chapter.