Gallic Acid Content and an Antioxidant Mechanism Are Responsible for the Antiproliferative Activity of ‘Ataulfo’ Mango Peel on LS180 Cells

• Main Authors: Gustavo. R. Velderrain-Rodríguez, Heriberto Torres-Moreno, Mónica A. Villegas-Ochoa, J. Fernando Ayala-Zavala, Ramón E. Robles-Zepeda, Abraham Wall-Medrano, Gustavo A. González-Aguilar
• Format: Article
• Language: English
• Published: MDPI AG 2018-03-01
• Series: Molecules
• Subjects: phenolic compounds; by-products; biological activity; LS180; colon cancer; antioxidant mechanism; single electron transfer (SET); hydrogen atom transfer (HAT)
• Online Access: http://www.mdpi.com/1420-3049/23/3/695

Mango “Ataulfo” peel is a rich source of polyphenols (PP), with antioxidant and anti-cancer properties; however, it is unknown whether such antiproliferative activity is related to PP’s antioxidant activity. The content (HPLC-DAD), antioxidant (DPPH, FRAP, ORAC), and antiproliferative activities (MTT) of free (FP) and chemically-released PP from mango ‘Ataulfo’ peel after alkaline (AKP) and acid (AP) hydrolysis, were evaluated. AKP fraction was higher (µg/g DW) in gallic acid (GA; 23,816 ± 284) than AP (5610 ± 8) of FR (not detected) fractions. AKP fraction and GA showed the highest antioxidant activity (DPPH/FRAP/ORAC) and GA’s antioxidant activity follows a single electron transfer (SET) mechanism. AKP and GA also showed the best antiproliferative activity against human colon adenocarcinoma cells (LS180; IC50 (µg/mL) 138.2 ± 2.5 and 45.7 ± 5.2) and mouse connective cells (L929; 93.5 ± 7.7 and 65.3 ± 1.2); Cheminformatics confirmed the hydrophilic nature (LogP, 0.6) and a good absorption capacity (75%) for GA. Data suggests that GA’s antiproliferative activity appears to be related to its antioxidant mechanism, although other mechanisms after its absorption could also be involved.