Production of a novel probiotic date juice with anti-proliferative activity against Hep-2 cancer cells

Abstract Date fruit is the ancient discovered and consumed fruit. Worldwide, Egypt is the largest producer of date. Besides its health benefits, many recent studies have proved its antioxidant, anticancer and anti-inflammatory effect. Currently, probiotic fermented fruit juices have a great attention especially for lactose intolerance patients. This study assessed the survival of two probiotics (Lactobacillus acidophilus and L. sakei) in the date juice. Phenolics characterization was performed by HPLC. Anti-proliferative activity of fermented juice against Caco-2 and Hep-2 cell lines was also evaluated. Under cold storage, L. sakei was still live for 2 weeks at 1.8 x 107 CFU/mL. In contrast, L. acidophilus reduced from 5.2 x 106 CFU/mL to below the minimum value of probiotic products just after 1 week. L. sakie significantly multiplied the total phenols and antioxidant activity in the juice compared to the unfermented juice. Interestingly, probiotic date juice exhibited an antitumor activity against larynx cell lines (Hep-2) with no activity against Caco-2. Date juice was proved to be suitable for probiotic and as potential larynx anticancer juice. Therefore, the developed juice is recommended to contribute to the available probiotic foodstuffs.

摘要 椰枣（Date fruit）是人类最早发现并食用的古老果品。全球范围内，埃及是最大的椰枣生产国。除具备多种健康益处外，多项近期研究已证实其具有抗氧化、抗肿瘤及抗炎功效。当前，益生菌（probiotic）发酵果汁备受关注，尤其适用于乳糖不耐受人群。本研究评估了两种益生菌——嗜酸乳杆菌（Lactobacillus acidophilus）与清酒乳杆菌（L. sakei）在椰枣汁中的存活情况。采用高效液相色谱法（High Performance Liquid Chromatography, HPLC）对酚类物质进行表征分析，并评估了发酵果汁对Caco-2细胞系与Hep-2细胞系的抗增殖活性。在冷藏条件下，清酒乳杆菌可存活2周，活菌数仍达1.8×10^7 菌落形成单位每毫升（Colony-Forming Units per mL, CFU/mL）。与之相反，嗜酸乳杆菌仅在1周后便从5.2×10^6 CFU/mL降至益生菌产品要求的最低活菌数阈值以下。与未发酵的椰枣汁相比，清酒乳杆菌可显著提升果汁中的总酚类物质含量与抗氧化活性。值得注意的是，益生菌椰枣汁对喉癌细胞系（Hep-2）展现出抗肿瘤活性，但对Caco-2细胞系无此效果。研究证实椰枣汁适宜作为益生菌载体，且具备开发为潜在喉部抗肿瘤饮品的潜力。因此，本研究开发的这款发酵椰枣汁可被纳入现有益生菌食品品类，具有推广应用价值。