Instituto de la Grasa (CSIC), Carretera de Utrera Km 1. Campus Universitario Pablo de Olavide. Building 46, 41013, Seville, Spain.
Technological Applications for Improvement of the Quality and Safety in Foods. R&D Division, Avda. Diego Martín Barrio 10. Second Floor, 41013, Seville, Spain.
Food Funct. 2024 Feb 19;15(4):1938-1947. doi: 10.1039/d3fo04223e.
This study evaluates the functional characteristics of the exopolysaccharide (EPS) extracts produced by various strains of (LPG1, 119, 13B4, and Lp13) and (Lp15) isolated from table olives. None of the EPS crude extracts showed cytotoxicity when administered to THP-1 human macrophage cells at dosages ranging from 6.25 to 50 μg mL. Many exhibited anti-inflammatory properties (reduction of pro-inflammatory cytokines TNF-α and IL-6 production) and antioxidant activity (reduction of ROS%) when macrophages were stimulated with lipopolysaccharide. Notably, the EPS extract produced by the LPG1 strain had the best results corroborated by western blot immune analysis for differential expression of COX-2, Nrf-2, and HO-1 proteins, with the most significant antioxidant and anti-inflammatory response observed at a dosage of 50 μg mL. Chemical analysis revealed that the EPS extract produced by this strain contains a heteropolymer composed of mannose (35.45%), glucose (32.99%), arabinose (17.93%), xylose (7.48%), galactose (4.03%), rhamnose (1.34%), and fucose (0.77%). Finally, we conducted response surface methodology to model the EPS extract production by LPG1 considering pH (3.48-8.52), temperature (16.59-33.41 °C) and salt concentration (0.03-8.77% NaCl) as independent variables. The model identified linear effects of salt and pH and quadratic effects of salt as significant terms. The maximum EPS extract production (566 mg L) in a synthetic culture medium (MRS) was achieved at pH 7.5, salt 7.0%, and a temperature of 20 °C. These findings suggest the potential for novel applications for the EPS produced by LPG1 as nutraceutical candidates for use in human diets.
本研究评估了从橄榄中分离出的 （LPG1、119、13B4 和 Lp13）和 （Lp15）不同菌株所产生的胞外多糖（EPS）提取物的功能特性。在剂量为 6.25 至 50 μg mL 时，没有一种 EPS 粗提取物对 THP-1 人巨噬细胞表现出细胞毒性。当巨噬细胞受到脂多糖刺激时，许多提取物表现出抗炎特性（减少促炎细胞因子 TNF-α 和 IL-6 的产生）和抗氧化活性（减少 ROS%）。值得注意的是，LPG1 菌株产生的 EPS 提取物效果最好，这一点通过 COX-2、Nrf-2 和 HO-1 蛋白差异表达的 Western blot 免疫分析得到证实，在 50 μg mL 的剂量下观察到最显著的抗氧化和抗炎反应。化学分析表明，该菌株产生的 EPS 提取物含有一种由甘露糖（35.45%）、葡萄糖（32.99%）、阿拉伯糖（17.93%）、木糖（7.48%）、半乳糖（4.03%）、鼠李糖（1.34%）和岩藻糖（0.77%）组成的杂多糖。最后，我们进行了响应面法，以 LPG1 生产 EPS 提取物为模型，考虑 pH（3.48-8.52）、温度（16.59-33.41°C）和盐浓度（0.03-8.77% NaCl）作为自变量。该模型确定了盐和 pH 的线性效应以及盐的二次效应是显著项。在合成培养基（MRS）中，EPS 提取物的最大产量（566 mg L）是在 pH 7.5、盐 7.0%和 20°C 的条件下实现的。这些发现表明，LPG1 产生的 EPS 作为人类饮食中使用的营养候选物具有新的应用潜力。
