Elicitation-Based Method for Increasing the Production of Antioxidant and Bactericidal Phenolic Compounds in <i>Dionaea muscipula</i> J. Ellis Tissue

• Main Authors: Wojciech Makowski, Krzysztof Michał Tokarz, Barbara Tokarz, Rafał Banasiuk, Karolina Witek, Aleksandra Królicka
• Format: Article
• Language: English
• Published: MDPI AG 2020-04-01
• Series: Molecules
• Subjects: antibiotic-resistant bacteria; biotic elicitation; <i>Cronobacter sakazakii</i>; DPPH; <i>Escherichia coli</i>; plant secondary metabolites
• Online Access: https://www.mdpi.com/1420-3049/25/8/1794

The carnivorous plant <i>Dionaea muscipula</i> J. Ellis (Venus flytrap) is a widely known medical herb, capable of producing various phenolic compounds known for their strong antioxidant and antibacterial properties. In the pharmaceutical industry, Venus flytrap is grown in tissue cultures, as the natural population of <i>D. muscipula</i> is very limited. Here, we describe an improved method to increase the quantity and quality of phenolic compounds produced in <i>D. muscipula.</i> This is achieved by combining biotic elicitation (using <i>Cronobacter sakazakii</i> bacteria lysate) of <i>D. muscipula</i> cultured with rotary shaking (hydromechanical stress), which we describe here for the first time. The antibacterial activity and the antioxidant properties of the obtained compounds were studied on two antibiotic-resistant human pathogenic bacteria. The proposed plant culture conditions resulted in an increase in fresh weight, as well as a higher total phenolic content, in comparison to traditional tissue cultures on agar-solidified medium. With the use of high-performance liquid chromatography, we demonstrated that the described elicitation strategy leads to an increased synthesis of myricetin, caffeic acid, ellagic acid and plumbagin in <i>D. muscipula</i> tissue. We also found that a higher level of antioxidant activity, exhibited by the plant extract, corresponded with its higher phenylpropanoid content. The bactericidal activity of the extract against <i>Staphylococcus aureus</i> was dependent on the duration of plant culture under described elicitation conditions, whereas neither elicitation condition (duration or elicitor concentration) seemed relevant for the bactericidal activity of the extract towards <i>Escherichia coli</i>. This suggest that Gram-negative bacteria are less sensitive to compounds derived from Venus flytrap tissue.