ABSTRACT
Next to cardiovascular disease, cancer remains the second leading cause of mortality and morbidity in the world. Breast cancer is the leading cancer type in women. The high rates of cervical and breast cancer burden among women have had a huge impact on health-related quality of life and increased the economic burden of several countries. Mastectomy, chemotherapy, axillary lymph node dissection, hormonal therapy, radiotherapy and targeted therapy are the common breast cancer treatment modalities. Several natural and synthetic drug molecules have been discovered, and the efficacy of these molecules has been assessed in vitro, in animal models as well as in human clinical trials. However, cancer incidence is on the rise, and there is a pressing need to identify novel and more efficient therapeutic approaches to combat the disease. Drug resistance is the most significant limiting problem, which diminishes the efficacy of cancer chemotherapy. Since ancient times, mankind has relied on plants for food and medicine. Plants or bioactive phytocompounds are known to both prevent and treat cancer. In this chapter, the mechanisms of key phytochemicals which bind to several classical targets and exhibit anticancer attributes through induction of beneficial pathways such as autophagy, mitohormesis, cell cycle arrest and apoptosis are summarized. There is a new vigor and interest in phytomedicine for breast cancer, because much like synthetic drugs, phytochemical formulations and isolated compounds possess anticancer properties. However, the advantage of phytochemical-based therapeutics is that these formulations may engender anticancer effects through synergistic mechanisms and thereby prevent the overt toxicity that is seen in routine cancer chemotherapy. Moreover, phytocompounds inhibit cancer-related inflammation, angiogenesis, oxidative stress, metastasis and cell cycle dysregulation. Due to the unique combinations of these effects, plant-based bioactive compounds have either been used directly or have served as effective scaffolds for QSAR-based modifications for the synthesis of novel drug candidates. Apart from summarizing the state of the art in phytomedicine-based cancer therapy, we recapitulate the potential uses of phytochemicals that we have identified from literature and in our own research (through in silico and in vitro studies), which may prevent as well as treat breast cancer. Established mechanisms of phytochemical action must be interpreted in the light of the murburn concept to further improve phytochemical therapy and drug biology/pharmacology. This knowledge can potentially open up new avenues for exploration of nutraceutical formulations which could both prevent and treat breast cancer.
