Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Nasr City, Cairo, 11884, Egypt.
BMC Microbiol. 2024 Oct 29;24(1):443. doi: 10.1186/s12866-024-03576-y.
Many lactic acid bacteria (LAB), known for their human health benefits, are derived from milk and utilized in biotherapeutic applications or for producing valuable nutraceuticals. However, the specific role of milk-associated LAB in biotherapeutics remains underexplored. To address this, eight milk product samples were randomly selected from the Egyptian market, diluted, and then cultured anaerobically on MRS agar. Subsequently, 16 suspected LAB isolates were recovered and underwent rapid preliminary identification. Among these isolates, the Lactobacillus plantarum strain with accession number (OQ547261.1) was identified due to its strong antioxidant activity depending on the DPPH assay, L. plantarum displayed notable antioxidant activities of 71.8% and 93.8% at concentrations of 125-1000 µg/mL, respectively. While ascorbic acid showed lower concentrations of 7.81, 3.9, and 1.95 µg/mL which showed activities of 45.1%, 34.2%, and 27.2%, respectively. The anti-inflammatory efficacy of L. plantarum was evaluated based on its capability to prevent hemolysis induced by hypotonic conditions. At a concentration of 1000 µg/mL, L. plantarum could reduce hemolysis by 97.7%, nearly matching the 99.5% inhibition rate achieved by the standard drug, indomethacin, at an identical concentration. Moreover, L. plantarum exhibited high hemolytic activity at 100 µg/mL (14.3%), which decreased to 1.4% at 1000 µg/mL. The abundance of phenolic acids and flavonoids was determined by high-performance liquid chromatography (HPLC) in L. plantarum. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) demonstrated that L. plantarum increased gene expression of the inflammatory marker TLR2 by 133%, and cellular oxidation markers SOD1 and SOD2 by 65% and 74.2%, respectively, while suppressing CRP expression by 33.3%. These results underscore L. plantarum's exceptional anti-inflammatory and antioxidant activities. Furthermore, L. plantarum induces cancer cell death through necrotic nuclear DNA fragmentation. These findings suggest that L. plantarum is not only suitable for nutraceutical production but also holds potential as a probiotic strain. Future research should focus on enhancing the capacity of this strain across various industries and fostering innovation in multiple fields.
许多乳酸杆菌（LAB）因其对人类健康的益处而被广泛应用，它们来源于牛奶，并被用于生物治疗应用或生产有价值的营养保健品。然而，牛奶相关 LAB 在生物治疗中的具体作用仍未得到充分探索。为了解决这个问题，我们从埃及市场随机选择了 8 个牛奶产品样本，进行稀释，然后在 MRS 琼脂上进行厌氧培养。随后，我们回收了 16 个疑似 LAB 分离株，并进行了快速初步鉴定。在这些分离株中，由于其 DPPH 测定的强抗氧化活性，我们鉴定出一株植物乳杆菌菌株，其 accession number（OQ547261.1）。植物乳杆菌在 125-1000µg/mL 浓度下的抗氧化活性分别为 71.8%和 93.8%，表现出显著的抗氧化活性。而抗坏血酸的浓度分别为 7.81、3.9 和 1.95µg/mL，其活性分别为 45.1%、34.2%和 27.2%。我们通过评估植物乳杆菌防止由低渗条件引起的溶血的能力来评估其抗炎功效。在 1000µg/mL 浓度下，植物乳杆菌可将溶血抑制率降低 97.7%，几乎与相同浓度的标准药物吲哚美辛的 99.5%抑制率相匹配。此外，植物乳杆菌在 100µg/mL 时表现出高溶血活性（14.3%），而在 1000µg/mL 时降低至 1.4%。我们通过高效液相色谱法（HPLC）测定了植物乳杆菌中酚酸和类黄酮的含量。实时定量逆转录聚合酶链反应（qRT-PCR）表明，植物乳杆菌使炎症标志物 TLR2 的基因表达增加了 133%，细胞氧化标记物 SOD1 和 SOD2 的基因表达分别增加了 65%和 74.2%，而 CRP 的基因表达则降低了 33.3%。这些结果突出了植物乳杆菌卓越的抗炎和抗氧化活性。此外，植物乳杆菌通过坏死核 DNA 片段化诱导癌细胞死亡。这些发现表明，植物乳杆菌不仅适合生产营养保健品，而且作为益生菌菌株也具有潜力。未来的研究应侧重于增强该菌株在各个行业的能力，并在多个领域推动创新。
