Anthocyanins and Phenolic Acids of Hybrid and Native Blue Maize (Zea mays L.) Extracts and Their Antiproliferative Activity in Mammary (MCF7), Liver (HepG2), Colon (Caco2 and HT29) and Prostate (PC3) Cancer Cells

Abstract

Blue maize is an excellent source of bioactive components such as phenolic acids and anthocyanins but when it is processed for human consumption, these compounds decrease considerably. Therefore, blue maize could be directed to produce nutraceutical extracts. The aim of this study was to evaluate the relation between anthocyanins composition of acidified and non-acidified extracts from native and hybrid blue maize genotypes and their antiproliferative effect in mammary (MCF7), liver (HepG2), colon (Caco2 and HT29) and prostate (PC3) cancer cells. The most abundant phenolic acid was ferulic acid. Nine anthocyanins were quantified in the extracts, being Cy3-Glu the most abundant. Acylated forms were also obtained in high abundance depending of the extraction method. An extract concentration range of 4.31 to 7.23 mg/mL inhibited by 50% the growth of untransformed cells NIH3T3. Antiproliferative effect on PC3, Caco2, HepG2 and MCF7 cancer cells of acidified extracts from hybrid blue maize was larger than the observed using non-acidified extracts. Among the nine compounds that were quantified in the extracts tested, CyMalGlu I showed the strongest correlation with the reduction of cell viability in Caco2 (-0.876), HepG2 (-0.813), MCF7 (-0.765) and PC3 (-0.894). No significant correlation or differences in antiproliferative effect on HT29 was found among the extracts. The method of extraction of maize anthocyanins must be selected to obtain a high yield of CyMalGlu I more than only Cy3-Glu since acylation affects the inhibition of cancer cell growth.

Effect of In Vitro Digestion on the Total Antioxidant Capacity and Phenolic Content of 3 Species of Oregano (Hedeoma patens, Lippia graveolens, Lippia palmeri)

“…Phenolic compounds are a heterogeneous group of compounds that are present in the vast majority of plant foods. There is epidemiological and in vitro experimental evidence associating the consumption of foods rich in phenolic compounds with a low incidence of chronic diseases, which are the leading cause of death worldwide (Bennett and others ; Mohamed ; Urias‐Lugo and others ). The main characteristics through which phenolic compounds have been reported to be bioactive are related to their antioxidant, immunomodulatory, chemopreventive, anti‐platelet aggregation and anti‐inflammatory properties (de la Lastra and Villegas ; Fraga and others ).…”

Bioactive Compounds in Pigmented Maize

“…There are reports that in white and yellow corn it can be found in the forms of dimers, trimers and tetramers [51]. Other authors have reported 1.94 mg/100 g [52] of free diferulic acid in blue Mexican corn which is the most abundant in that variety ( Table 5).…”

The Maize Contribution in the Human Health

“…The group of non-anthocyanin flavonoids includes flavonols (rutin, isoquercetin, flavonol, morin, kaempferol, and quercetin) and flavonones (naringenin and hesperetin) [26], while the phenolic acids found in corn are protocatechuic acid, vanillic acid, syringic acid, trihydroxybenzoic acid, caffeic acid, chlorogenic acid, and p-hydroxyphenylacetic acid. Ferulic acid and p-coumaric acid are the compounds with more concentrates in corn, particularly in pigmented varieties [27,28]. Total ferulic acid content detected in kernels of white varieties with Mexican genotype has been reported as 124,053 mg of ferulic acid equivalent/100 g of sample, while pigmented varieties such as blue or red corn have reported 129,985 and 130,297 mg of ferulic acid/100 g sample, respectively [15].…”

“…In 2015, Mexican researchers conducted a study with extracts of phenolic acids and blue corn anthocyanins, measuring their anticancer properties in breast, liver, colon, and prostate cancer cell lines; results indicated an antiproliferative effect in all cell lines, in which malonyl glucoside cyanidin was the anthocyanin with the greatest reduction in cell viability [28]. It has also been shown that the bioactive peptides of corn exert antitumor activity through key mechanisms such as (a) the induction of apoptosis mediated through specific proteases or caspases; strategies to overcome tumor resistance to apoptotic pathways include the activation of pro-apoptotic receptors, the restoration of p53 activity, the modulation of caspases, and the inhibition of the proteasome; (b) blocking the intermediate generation of tumors by regulating cellular mechanisms associated with cell proliferation and survival, or biosynthetic pathways that control cell growth; and (c) regulation of immune system functions, increasing the expression of antigens associated with the tumor (antigenicity) in cancer cells, activating the tumor cells for them to release warning signals that stimulate the immune response (immunogenicity), or increasing the predisposition of the tumor cells to be recognized and neutralized by the immune system (susceptibility) by means of autophagy and apoptosis [63].…”