Bioactive Compounds from Medicinal Plants for Cancer Therapy and Chemoprevention

Malignant diseases have been highlighted as one of the most prominent causes of human mortality worldwide. The prevalence of cancer is constantly increasing and is expected to reach three-fourths of the population in the next two decades. Conventional cancer treatment involves surgery, controlling and reducing the growth of cancer tissues using radiation, and chemotherapy. Many incidences prove that chemical treatment for cancer is immensely associated with the recurrence of cancer, and the development of resistance, and is prone to severe side effects. Since natural products have now been used in the treatment of various diseases, the anticancer properties of natural drugs and druggable products are interceded by various mechanisms, including the initiation of programmed cell death, modulations in the immune system, and inhibition of angiogenesis. Edible, medicinal plants and spices used in traditional medicine to regulate vital molecular targets are important chemopreventive agents in the treatment of chemo and radiation therapy-induced toxicities in drug development. Natural agents could trigger cell death signalling pathways in tumour cells by stimulating anti-apoptotic proteins and/or overcoming pro-apoptotic proteins and caspases. It inhibit protein kinase B (Akt), phosphatidylinositide 3-kinases (PI3K), epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK), as well as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Bax/Bcl-2 ratio changes, inhibiting cellular proliferation, and differentiation, and also activating apoptosis lead to less prominence. To summarize, this chapter highlights the current status, and forthcoming prospects of cancer treatment and prevention as well as the potential of bioactive compounds that have been used in cancer treatment and chemoprevention.

Cancer is identified as the second-most deadly disease all over the world. Various advancements have been made in the treatment of cancer to protect the life of human beings. However, the side effects may destroy the lives of the patients. Economically poor patients cannot afford the treatment, and they live short lives with cancer. So nowadays, research is going on to search for drugs without any side effects and that are cheap with good efficacy. Some medicinal plants have a lot of potential to act as anticancer agents but are not medically proven as discussed in this chapter. This review will focus on the various plant-derived chemical compounds that have shown anticancer activity.

The relatively unexplored marine environment is a rich resource of novel bioactive candidates that may be beneficial for human beings. Since the marine environment is complex in nature, living organisms produce secondary metabolites with unique biological properties that could find applications in health care systems. This chapter gives an overview of marine-based anticancer drugs that are FDAapproved and bioactive components that are under preclinical and clinical trials. It also provides insight into marine-based nutraceuticals, their sources, and their usefulness for various human health concerns. Therefore, exploring the marine environment through collaborative research work both by academia and industries could lead to significant contributions to humanity. 

The continuous increase in the number of cancer cases and rates of cancer-related mortality globally is a highly concerning issue. Drug-induced toxicity, drastic side effects and chemoresistance associated with conventional chemotherapeutics warrant the need for novel, efficient, and safer alternative therapeutic approaches to help combat cancer. Plants are a rich source of bioactive compounds with potential anti-cancer activity. Extensive research on the chemotherapeutic efficacy of various plant-derived bioactive compounds is being carried out across the world. While cancer chemoprevention approaches prevent, delay, or suppress tumor incidence, chemosensitization approaches employ synthetic or natural bioactive agents to enhance the efficacy of conventional chemotherapeutic drugs at lower doses. Numerous studies have documented the efficiency of both of these approaches in managing different types of cancer. The scope of this chapter encompasses a comprehensive analysis of the current status and limitations of conventional chemotherapeutics and the clinical relevance of chemoprevention and chemosensitization strategies for the effective management of cancer, with a special emphasis on the potency of some of the major phytochemicals that are extensively being studied as novel chemopreventives and/or chemosensitizers, globally. Besides, an overview of the underlying mechanisms of action of these phytochemicals in regulating the signal transduction events associated with cancer progression, has also been discussed in this chapter.

Every year, millions of individuals are diagnosed with cancer, making it one of the primary causes of mortality worldwide. It is estimated that around 10 million cancer-related deaths will occur, emphasizing the enormity of the impact of this disease on individuals and society as a whole. There are a multitude of side effects associated with anticancer drugs, and each drug, regardless of its class, has its unique set of adverse reactions. The overproduction of reactive oxygen species (ROS) and consequent accumulation of oxidative stress are significant contributors to adverse reactions, particularly for medications directed towards DNA. This issue has prompted the exploration of various dietary supplements to mitigate these unwanted side effects. Among these supplements, antioxidants have become increasingly prevalent as a chemotherapy adjuvant. Nevertheless, many cancer specialists discourage the consumption of antioxidant-rich supplements, as they have the potential to interfere with cancer-killing modalities that generate free radicals. There is ongoing debate regarding whether the use of antioxidant supplements impacts the effectiveness of cancer chemotherapy. Specific antioxidant supplements may lessen toxicities and bad effects, according to limited evidence that is both high quality and sample size. In this chapter, details of the role of antioxidants in cancer therapy and chemoprevention are discussed.

Psychotria nilgiriensis was used in traditional medicine as to cure chronic inflammatory diseases. Therefore, the evaluation of different combination of solventbased fractions from stem and leaves of P. nilgiriensis for free radical scavenging activity, inhibitory potential against nitric oxide radicals, and tentative identification of active metabolites were carried out. The antioxidant activity of solvent extracts was determined by DPPH· scavenging, TAC, and ORAC assays using spectrophotometer analysis. Further, nitric oxide production inhibition was studied in lipopolysaccharide (LPS)-activated macrophages RAW 264.7 cells. Fraction-based bioactive chemical compound identification was performed using an LC-MS metabolomics approach. With each of the assays, activity was observed with various extracts derived from both the stem and the leaf. The two active extracts, one obtained with Psychotria nilgiriensis leaf ethyl acetate: methanol (PLEM, 40/60 v/v), and another one obtained with P. nilgiriensis stem chloroform: ethyl acetate (PSCE, 70/30 v/v), about 10-15% of the chemical components were identified. With PLEM, N,N-bis(2-ethylhexyl)hydroxylamine was higher in concentration, whereas PSCE, N,N-dioctylhydroxylamine was higher in concentration compared to other metabolites. Thus, the present findings suggest that the P. nilgiriensis leaf and stem could have medicinal value as an antioxidant for the treatment of inflammatory diseases. Some of the chemical constituents such as hydroxylamine derivatives could also be of value.

 Cancer is still a disease that many people fear. Cancer patients frequently have side effects from chemo- and radiotherapy that lower their quality of life and may force them to stop receiving their treatment. For centuries, people have employed natural products, particularly plants, to heal a wide range of illnesses. Powerful bioactive compounds that are produced from plants can be employed as medications. The uniqueness and potency of anticancer therapeutic medicines originating from plants are now being explored in research studies. Using sophisticated analytical techniques, the healthcare industry is attempting to comprehend the physio-chemical characteristics of these plant derived compounds and their contributions to the treatment of cancer. Some of these compounds are thought to be candidates for use as chemopreventive medicines and may even be combined with traditional chemotherapy in certain circumstances. The purpose of this book chapter is to highlight important plant derived compounds, their properties, mechanism of action and ongoing clinical trials for cancer prevention and treatment. The suitability and lethality of medicinal and herbal plants are a subject of considerable debate despite their many powerful benefits. Here, we discuss advantages, limitations and current status of recruiting plant derived compounds as chemopreventive and chemotherapeutic drugs. 

Cancer is still the second-leading cause of death in industrialized countries. The development of resistance to anticancer drugs and the severe side effects of current drugs prevent treatment with drug doses high enough for long-lasting remissions or sustainable cures. There have been unprecedented efforts to uncover new treatments and the knowledge of cancer has been tremendously increasing for the past few decades. Medicinal plants are a fertile ground to be used as phytotherapy and to isolate phytochemicals with interesting pharmacological features. Medicinal plants are being increasingly documented as useful consistent treatments for cancer. A large volume of clinical studies have reported the beneficial effects of herbal medicines on the survival, immune modulation, and quality of life (QOL) of cancer patients when these herbal medicines are used in combination with conventional therapeutics. This book chapter should provide useful technological support for the evidence-based application of herbal medicines in cancer therapy. Natural products have always been a major source of drug development in cancer therapy.