4.1 Introduction
Cancer is one of the greatest consequential cause for the death of world human
population every year (Zaorsky et al. 2017). The extensive search for therapeutic
agents, predominantly the green phytochemicals derived from medicinal plants, has
recently gained high momentum especially for cancer prevention and cure (Zhang
et al. 2020). Various plants have shown beyond doubt their worth as a source of
phytochemicals with therapeutic potential and still represent as an important source
for the discovering of new therapeutic agents which leads as the blue print for
chemically synthetic compound (Newman and Cragg 2012). Phytochemicals are
plant’s (phyto) bioactive non-nutrient chemicals referring to various types of
compounds that occur naturally in plants (Liu 2004; Mousavi et al. 2018). The
utilization of plants has a long-established history in traditional treatment of various
diseases. The breakthrough in chemical field with the advances in chemical analysis
lead to the isolation and characterization of various purified bioactive compounds of
plants, which initiated the exploration of plant sources as chemotherapeutic candidates for cancer (Cragg and Newman 2005). The continuous rise in cancer cases
and the failure of synthetic conventional chemotherapies due to drug resistance and
excessive toxicity towards healthy normal non-targeted tissues have also pushed to
the utilization of naturally occurring phytochemicals of plants, which is evidently
shown to improve treatment efficiency with lesser side effects. According to
increasing scientific evidences confirming the remarkable anticancer activity
induced by phytochemicals derived from plants has prompted to explore the role of
phytochemicals in cancer cure. Green phytochemical from Mother Nature especially from medicinal plants are a rich source of novel therapeutics and prevention
agents. In reality, some of the commonly used and commercially available anticancer drugs were isolated from medicinal plants, namely vinblastine, and vincristine (Newman et al. 2011). Interestingly, their unique mechanism of action as
compared with the conventional drug mechanism against cancer cells made them a
vital target for novel drug discovery for cancer prevention and cure. The important
characteristic of plant-based phytochemical is that they can kill the cancer cells with
least toxicity. Moreover, phytochemical also exhibits a higher selectivity towards
cancer cells in comparison to normal non-cancerous cells. Most plants do yield a
vast array of phytochemicals that play essential roles in cancer prevention and cure
via various biological activities and novel mechanisms of actions. Since cancer has
a significant impact on human health and contributes to mortality, it is appropriate
to examine the role of phytochemicals in cancer prevention and cure (Vineis and
Fecht 2018). The objective of this chapter is to furnish the role of phytochemicals in
cancer prevention and cure that addressed various mechanisms of actions of various
phytochemicals against the cancer cells as reported in the literature. Hence, this
chapter provides a comprehensive overview of the role of phytochemicals in cancer
prevention and cancer cures via antioxidant activity, pro-oxidant activity, apoptosis
induction, necrosis induction, autophagy induction and regulation of miRNA in
cancer cells as shown in Fig. 4.1.
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B. Cilwyn et al.
Cancer is one of the greatest consequential cause for the death of world human
population every year (Zaorsky et al. 2017). The extensive search for therapeutic
agents, predominantly the green phytochemicals derived from medicinal plants, has
recently gained high momentum especially for cancer prevention and cure (Zhang
et al. 2020). Various plants have shown beyond doubt their worth as a source of
phytochemicals with therapeutic potential and still represent as an important source
for the discovering of new therapeutic agents which leads as the blue print for
chemically synthetic compound (Newman and Cragg 2012). Phytochemicals are
plant’s (phyto) bioactive non-nutrient chemicals referring to various types of
compounds that occur naturally in plants (Liu 2004; Mousavi et al. 2018). The
utilization of plants has a long-established history in traditional treatment of various
diseases. The breakthrough in chemical field with the advances in chemical analysis
lead to the isolation and characterization of various purified bioactive compounds of
plants, which initiated the exploration of plant sources as chemotherapeutic candidates for cancer (Cragg and Newman 2005). The continuous rise in cancer cases
and the failure of synthetic conventional chemotherapies due to drug resistance and
excessive toxicity towards healthy normal non-targeted tissues have also pushed to
the utilization of naturally occurring phytochemicals of plants, which is evidently
shown to improve treatment efficiency with lesser side effects. According to
increasing scientific evidences confirming the remarkable anticancer activity
induced by phytochemicals derived from plants has prompted to explore the role of
phytochemicals in cancer cure. Green phytochemical from Mother Nature especially from medicinal plants are a rich source of novel therapeutics and prevention
agents. In reality, some of the commonly used and commercially available anticancer drugs were isolated from medicinal plants, namely vinblastine, and vincristine (Newman et al. 2011). Interestingly, their unique mechanism of action as
compared with the conventional drug mechanism against cancer cells made them a
vital target for novel drug discovery for cancer prevention and cure. The important
characteristic of plant-based phytochemical is that they can kill the cancer cells with
least toxicity. Moreover, phytochemical also exhibits a higher selectivity towards
cancer cells in comparison to normal non-cancerous cells. Most plants do yield a
vast array of phytochemicals that play essential roles in cancer prevention and cure
via various biological activities and novel mechanisms of actions. Since cancer has
a significant impact on human health and contributes to mortality, it is appropriate
to examine the role of phytochemicals in cancer prevention and cure (Vineis and
Fecht 2018). The objective of this chapter is to furnish the role of phytochemicals in
cancer prevention and cure that addressed various mechanisms of actions of various
phytochemicals against the cancer cells as reported in the literature. Hence, this
chapter provides a comprehensive overview of the role of phytochemicals in cancer
prevention and cancer cures via antioxidant activity, pro-oxidant activity, apoptosis
induction, necrosis induction, autophagy induction and regulation of miRNA in
cancer cells as shown in Fig. 4.1.
128
B. Cilwyn et al.