Quagliariello Vincenzo, Iaffaioli Rosario Vincenzo, Falcone Mariangela, Ferrari Giovanna, Pataro Gianpiero, Donsì Francesco
Department of Abdominal Oncology, National Cancer Institute "G. Pascale", Via M. Semmola, 80131 Naples, Italy; ASMO (Association for Multidisciplinary Studies in Oncology) and Mediterranean Diet, Piazza Nicola Amore 6, 80138 Naples, Italy.
ProdAl Scarl, via Ponte don Melillo, 84084 Fisciano, SA, Italy.
Food Res Int. 2016 Sep;87:115-124. doi: 10.1016/j.foodres.2016.07.005. Epub 2016 Jul 7.
The bioactive compounds of brown rice exhibit many beneficial health effects, ranging from antioxidant to cytotoxic activities. Pulsed Electric Field (PEF) pretreatment can significantly enhance their extraction, through the induction of the electro-permeabilization of the cell membranes. This paper aims to demonstrate that PEF-assisted extraction of brown rice enables not only enhanced yields of antioxidant compounds, such as γ-oryzanol, polyphenols and phenolic acids, and of saturated and unsaturated fatty acids, but also increased cytotoxic effects on cancer cells. Initially, the PEF-assisted extraction conditions have been defined by the assessment of the cell permeabilization index via impedance measurements and the DPPH antioxidant activity. Subsequently, the biological effects of PEF have been evaluated on the cytotoxicity and anti-inflammatory properties against human colon cancer cell line HT29. The results show that PEF-assisted extraction, enhancing the yield of bioactive compounds, with respect to untreated extracts, significantly promotes their antioxidant activity, which is correlated with an increased HT29 cells cytotoxicity. In addition, PEF extracts of brown rice substantially inhibit also gene expression and interleukin production in colon cancer cells, suggesting their exploitation as natural anti-inflammatory agents. The integration of PEF pretreatment in the solvent extraction process of bioactives from brown rice appears, therefore, as a promising practice to significantly enhance their biological activity.
糙米的生物活性化合物具有许多有益的健康功效，从抗氧化到细胞毒性活性不等。脉冲电场（PEF）预处理可通过诱导细胞膜的电通透化作用，显著提高其提取物的含量。本文旨在证明，PEF辅助提取糙米不仅能提高抗氧化化合物（如γ-谷维素、多酚和酚酸）以及饱和与不饱和脂肪酸的产量，还能增强对癌细胞的细胞毒性作用。首先，通过阻抗测量评估细胞通透化指数和DPPH抗氧化活性来确定PEF辅助提取条件。随后，评估了PEF对人结肠癌细胞系HT29的细胞毒性和抗炎特性的生物学效应。结果表明，与未处理的提取物相比，PEF辅助提取提高了生物活性化合物的产量，显著促进了其抗氧化活性，这与HT29细胞毒性增加相关。此外，糙米的PEF提取物还能显著抑制结肠癌细胞中的基因表达和白细胞介素产生，表明它们可作为天然抗炎剂加以利用。因此，将PEF预处理整合到糙米生物活性物质的溶剂提取过程中，似乎是一种显著提高其生物活性的有前景的做法。
