Antineoplastic with DNA fragmentation assay and anti-oxidant, anti- inflammatory with gene expression activity of Lactobacillus plantarum isolated From local Egyptian milk products

Abstract

Probiotic bacteria are emerging as promising biotherapeutic agents and environmentally friendly alternatives to antibiotics. They play crucial roles as antioxidants and anti-inflammatory agents, all while minimizing adverse side effects. A significant portion of lactic acid bacteria (LAB), known for their human health benefits, are derived from milk and have been utilized in biotherapeutic applications or for producing valuable metabolites (nutraceuticals). However, the specific role of milk-associated LAB in biotherapeutics remains underexplored. To address this, eight milk product samples were randomly selected from a market in Egypt, diluted, and then cultured anaerobically on MRS agar. From these samples, 16 suspected LAB isolates were obtained and underwent rapid preliminary identification. Among these isolates, the Lactobacillus plantarum strain (OQ547261.1) was identified and shown to exhibit strong antioxidant activity. This activity was evaluated using the DPPH assay at various concentrations, ranging from 1000 to 1.95 µg/mL. The results revealed that L. plantarum displayed notable antioxidant activities of 71.8% and 93.8% at concentrations of 125–1000 µg/mL, respectively. In contrast, lower concentrations of 7.81, 3.9, and 1.95 µg/mL showed activities of 45.1%, 34.2%, and 27.2%, respectively, compared to ascorbic acid (the standard reference drug). The anti-inflammatory efficacy of L. plantarum was evaluated based on its capability to prevent hemolysis induced by hypotonic conditions in a laboratory setting. At a concentration of 1000 µg/mL, L. plantarum managed to 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. Analysis using high-performance liquid chromatography (HPLC) determined the presence of polyphenolic compounds in L. plantarum, showing an abundance of phenolic acids and flavonoids. 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.