1.
Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention.
Kapinova, A, Kubatka, P, Golubnitschaja, O, Kello, M, Zubor, P, Solar, P, Pec, M
Environmental health and preventive medicine. 2018;23(1):36
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Bioactive phytochemicals are continually being studied for their role in cancer prevention with increasing evidence for flavonoids, carotenoids, phenolic acids, and organosulfur compounds (found in cruciferous vegetables). This 2018 review explores the protective effects of a broad spectrum of plant-derived substances. In total, more than 5000 individual phytochemicals have been identified in plant-derived foods, such as fruits, vegetables, and grains. These bioactive compounds have been shown to have antitumor activity, reduce inflammation, induce apoptosis (cell death), inhibit the proliferation of aggressive tumour cells, and impact on metastasis (migration of cancer cells). Specifically, in breast cancer, a few studies have examined phytochemicals on cancer stem cells (the originating tumour cells) and found that curcumin, genistein, indol-3-carbinol, c-phycocyanin, resveratrol, and quercetin downregulated their activity. Systematic reviews of dietary patterns and breast cancer show vegetables, and especially fibre, to be consistently protective against reduced risk of mammary carcinogenesis. Dietary polyphenols are considered a cost-effective approach to cancer care however there is still a lack of evidence due to the complex nature of combined phytochemicals versus isolated agents. Wholefood consumption is considered to improve bioavailability compared to supplementation however phytochemicals are a low-dose component of foods. There is also concern that some phytochemicals may act as carcinogens or tumour promoters (for example, beta-carotene). More clinical trials are required to fully understand phytochemicals and breast cancer care.
Abstract
Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.
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Phytochemicals in Skin Cancer Prevention and Treatment: An Updated Review.
Ng, CY, Yen, H, Hsiao, HY, Su, SC
International journal of molecular sciences. 2018;19(4)
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This 2018 review discusses the anti-oxidative, anti-inflammatory, anti-proliferative, and anti-angiogenic effects of phytochemicals for the management of skin cancer. Melanoma and non-melanoma skin cancers are caused by cellular DNA damage, and as the skin is the body’s largest organ, it is most exposed to environmental stimulus. There are several promising phytochemicals in cancer chemoprevention including Epigallocatechin-3-gallate, resveratrol, curcumin, proanthocyanidins, silymarin, apigenin, capsaicin, genistein, indole-3-carbinol, and luteolin. Additionally, Gingerol has been applied topically to improve chemical stability in the skin. Caffeic Acid Phenethyl Ester (CAPE) is derived from bee propolis was shown to inhibit skin papilloma in animal studies. Capsaicin from red chillies induced apoptosis (cell death) in melanoma cells. Curcumin has been shown to modify numerous inflammatory markers including C-reactive protein and COX-2 whilst topically can promote remarkable symptomatic relief and reduce external cancer lesion size. Caffeic Acid exerts a protective effect towards skin cancer migration and invasion. EGCG has been shown to sensitize melanoma cells to inhibit growth, promote cell death and decrease cell proliferation. Genistein from soy has been shown to exert anti-angiogenesis properties, reduce tumour proliferation and metastasis. Resveratrol has a synergistic effect with other phytochemicals to suppress tumours. What all the studies reviewed show is the potential for phytochemicals in cancer treatment. They are widely available, cost effective and highly tolerated. They appear to have anti-carcinogenic effects through regulation of multiple different signalling pathways which help alter the typical progression of skin cancer.
Abstract
Skin is the largest human organ, our protection against various environmental assaults and noxious agents. Accumulation of these stress events may lead to the formation of skin cancers, including both melanoma and non-melanoma skin cancers. Although modern targeted therapies have ameliorated the management of cutaneous malignancies, a safer, more affordable, and more effective strategy for chemoprevention and treatment is clearly needed for the improvement of skin cancer care. Phytochemicals are biologically active compounds derived from plants and herbal products. These agents appear to be beneficial in the battle against cancer as they exert anti-carcinogenic effects and are widely available, highly tolerated, and cost-effective. Evidence has indicated that the anti-carcinogenic properties of phytochemicals are due to their anti-oxidative, anti-inflammatory, anti-proliferative, and anti-angiogenic effects. In this review, we discuss the preventive potential, therapeutic effects, bioavailability, and structure-activity relationship of these selected phytochemicals for the management of skin cancers. The knowledge compiled here will provide clues for future investigations on novel oncostatic phytochemicals and additional anti-skin cancer mechanisms.