An overview on the role of dietary phenolics for the treatment of cancers

Abstract

Plant derived phenolic compounds have been shown to inhibit the initiation and progression of cancers by modulating genes regulating key processes such as: (a) oncogenic transformation of normal cells; (b) growth and development of tumors; and (c) angiogenesis and metastasis. Recent studies focusing on identifying the molecular basis of plant phenolics-induced cancer cell death have demonstrated down-regulation of: (a) oncogenic survival kinases such as PI3K and Akt; (b) cell proliferation regulators that include Erk1/2, D-type Cyclins, and Cyclin Dependent Kinases (CDKs); (c) transcription factors such as NF-kβ, NRF2 and STATs; (d) histone deacetylases HDAC1 and HDAC2; and (e) angiogenic factors VEGF, FGFR1 and MIC-1. Furthermore, while inhibiting oncogenic proteins, the phenolic compounds elevate the expression of tumor suppressor proteins p53, PTEN, p21, and p27. In addition, plant phenolic compounds and the herbal extracts rich in phenolic compounds modulate the levels of reactive oxygen species (ROS) in cells thereby regulate cell proliferation, survival and apoptosis. Furthermore, recent studies have demonstrated that phenolic compounds undergo transformation in gut microbiota thereby acquire additional properties that promote their biological activities. In vitro observations, preclinical and epidemiological studies have shown the involvement of plant phenolic acids in retarding the cancer growth. However, to date, there is no clinical trial as such testing the role of plant phenolic compounds for inhibiting tumor growth in humans. More over, several variations in response to phenolic acid rich diets-mediated treatment among individuals have also been reported, raising concerns about whether phenolic acids could be used for treating cancers. Therefore, we have made an attempt to (a) address the key structural features of phenolic acids required for exhibiting potent anti-cancer activity; (b) review the reported findings about the mechanisms of action of phenolic compounds and their transformation by gut microbiota; and (c) update the toxicological aspects and anti-tumor properties of phenolic compounds and extracts containing phenolic compounds in animals.

Comparative assessment of phytochemical composition, antioxidant and anticholinesterase activities of two Basidiomycota Truffle Fungi from Turkey

“…Phenolic compounds are secondary metabolites capable of exhibiting antioxidant, antimicrobial, anti-inflammatory and anti-cancer activities [20]. Because of this biological …”

Edible flowers as sources of phenolic compounds with bioactive potential

“…The consumption of various types of edible flowers provides health benefits to the consumer, since they are a good source of phytochemicals, including phenolic compounds (Fernandes et al, 2017). These compounds have been related to the prevention of chronic degenerative diseases, such as diabetes, cognitive decline, and cardiovascular disease, as well as different types of cancer through the inhibition of their initiation and progression by modulating genes involved in key regulation processes (Anantharaju, Gowda, Vimalambike, & Madhunapantula, 2016;Gutiérrez-Grijalva et al, 2016). The flowers may contain a variety of these natural antioxidants such as phenolic acids and flavonoids, being their presence strongly related to their colour either directly (e.g., anthocyanins and other flavonoid pigments) or indirectly through the copigmentation processes (Brouillard, 1988;Kaisoon, Siriamornpun, Weerapreeyakul, & Meeso, 2011).…”

Validated HPTLC technique for simultaneous evaluation of biomarkers gallic acid and quercetin in Trichosanthes dioica Roxb.: A systematic approach for quality control of herbals

“…Many studies have reported QE as a major flavanol in apple, berries, carpers, onions and tea [6], and its protective role towards cardiovascular, cancer and inflammatory conditions [7]. The previous reports reveal that the GA and its derivatives possess wide spectrum of biological activities like antimicrobial [8], anticancer [9], antiviral, anti-inflammatory [10], analgesic [11] and anti-HIV activities [12].…”