**Anthocyanin Profile of Red Maize Native from Mixteco Race and Their Antiproliferative Activity on Cell Line DU145**

Mónica Herrera-Sotero, Francisco González-Cortés, Hugo García-Galindo, Enrique Juarez-Aguilar, Mauricio Rodríguez Dorantes, José Chávez-Servia, Rosa Oliart-Ros and Rosa Guzmán-Gerónimo

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/67809

#### **Abstract**

Mexico is regarded as the point of origin and biodiversity of maize, which takes the colors white, yellow, blue, or red. Red maize in particular owes its coloring to a type of polyphenolic compounds known as anthocyanins. The aim of this study was to determine the profile anthocyanin of red maize, as well as their antiproliferative activity on prostate cancer cell line DU145. Three samples of red maize were analyzed. Total polyphenols, monomeric anthocyanins, antioxidant activity by DDPH and FRAP were evaluated. The sample of red maize with the highest levels of total polyphenols and monomeric anthocyanins was selected, and its anthocyanin fraction was analyzed by HPLC-ESI-MS. Twenty compounds were detected in the anthocyanin profile, and from these, 12 anthocyanins derived of cyanidin were identified. MTT assay was used to determine the antiproliferative activity of the anthocyanin fraction from red maize at different concentrations (7–1000 μg/mL), and a significant antiproliferative activity was observed at 1000 μg/mL. Microscopy analysis showed that the anthocyanin fraction of red maize induced apoptosis in cell lines DU145. This is the first report showing that anthocyanin fraction of red maize possess antiproliferative activity in the DU145 cell line.

**Keywords:** red maize, phenolic compounds, anthocyanin profile, antiproliferative activity, DU145 cell line

© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

## **1. Introduction**

Cereals are still the most important food source worldwide. Maize, sorghum, millet, wheat, rice, barley, oats, teff, and quinoa account for a large amount of the human diet. Maize (*Zea mays* L.) is the third crop by volume cultivated in the world and has a great economic importance, since it is used for animal and human foods as well as a raw material in the production of several industrial products [1]. There are over 59 maize races in Mexico [2] with different shapes and colors, such as white, yellow, blue, and red. In recent years, there has been a growing interest in pigmented varieties form the scientific point of view, since they are sources of phenolic compounds. Approximately 60% of polyphenols are flavonoids, which are regarded as the most important group of phenolic compounds. Among these are anthocyanins, the chemical compounds responsible for the color of red maize, which are located in the pericarp or aleurone layer of the grain [3].

Anthocyanins are generally regarded as the most important pigments in nature. These water-soluble compounds belong to the flavonoid family and can be found in the colors blue, red, purple, and dark violet [4]. From the chemical standpoint, anthocyanins in nature take the form of glycosides, whose aglycone is known as anthocyanidin. Anthocyanidins are made up of a benzopyril system (A–C) and a phenolic ring (B). Particular differences between anthocyanins depend upon the number of hydroxyl groups, the nature and number of glycosides attached to the molecule, the position of the point of attachment, and to the nature and number of aromatic acids joined to the glycoside in the molecule [5]. Since each anthocyanidin may be glycosylated and acylated by different acids at different points, there is a large number of chemical combinations [6]. Furthermore, the simplest or monomeric anthocyanins may react between themselves, producing more complex structures of higher molecular weights known as polymeric anthocyanins. They may also react with other compounds, and therefore, in nature more than 600 different anthocyanins are found.

On the other hand, there is a growing scientific interest on pigmented maize races such as red, due to their content of anthocyanins. Experts recommend the consumption of these because of their strong free-radical scavenging activity and chelation of divalent cations, which is given by their phenolic structure, double bonds of their rings, and hydroxyl groups. Anthocyanins may also modulate enzymes related to oxidative stress, and their preventive action in the development of disease has been reported [7].

Several epidemiological studies also reveal that the consumption of flavonoid-rich foods is associated with a lower risk of neurodegenerative diseases such as cancer [8–10]. Cancer is one of the main causes of death worldwide, causing 7.6 million deaths only in 2008. For 2030, this number of cancer victims is expected to increase to 11 million. Lung, breast, colorectal, stomach, and prostate cancers cause the majority of cancer deaths [11]. The treatment of this disease depends on the type of cancer as well as on the subtype or stage of the patient and is currently based on hormones, chemotherapy, radiotherapy, pharmaceuticals, and nanotherapy. However, these treatments are aggressive, highly expensive, and unattainable for many people [12]. Unfortunately, some cancer tumors are extremely resistant to current therapeutic agents; therefore, the development of new strategies in prevention, treatment, and control of cancer is urgently needed [13].

The scientific community is looking for alternatives, such as the use of natural compounds as chemopreventives or adjuvants. In this regard, red maize form Mixteco race may be an important source of flavonoids; however, the number of studies investigating the antiproliferative activity of this grain is scarce. Given the above, the aim of the present work was to evaluate the antiproliferative activity of purified anthocyanins from red maize in the prostate cancer cell line DU145.
