Woodfordia fruticosa extract nanoemulsion: Influence of processing treatment on droplet size and its assessment for in vitro antimicrobial and anti-inflammatory activity

Abstract

Recently, plant-derived bioactive compounds have been utilized in the preparation of several functional food products; however, stability and water solubility are major constraints to these compounds. Therefore, to overcome this problem, the synthesis of nanoemulsion (oil in water) with varying concentrations of Woodfordia fruticosa flower extract (1%−10% w/v) was carried out and characterization of nanoemulsion was done. The average droplet size of nanoemulsion samples ranges from 149.25 to 244.33 nm. The control and WFNE3 nanoemulsion showed significantly (p < 0.05) higher thermal stability when correlated with average droplet size. An insignificant difference (p > 0.05) was observed in the average droplet size and zeta potential WFNE3 (−30.3mV) with the increased temperature rate. At varied pH ranges, WFNE3 showed significantly higher (p < 0.05) stability in comparison with the control nanoemulsion sample. In terms of ionic strength, WFNE3 nanoemulsion sample showed significantly (p < 0.05) higher stability, and with an increasing concentration of salt, the colloidal system of the WFNE3 sample showed significantly (p < 0.05) higher droplet size (318.91 nm). Therefore, the antimicrobial potential of WFNE3 nanoemulsion in comparison with extract of W. fruticosa flower extract was studied against Gram-positive Staphylococcus aureus, Gram-negative bacteria Pseudomonas aeruginosa, and fungal strain Candida albicans, respectively. WFNE3 nanoemulsion sample in comparison to flower extract showed a significantly higher (p < 0.05) zone of inhibition against gram-negative bacteria as compared to the control nanoemulsion sample upon storage for 7 days. WFNE3 nanoemulsion sample showed significant (p < 0.05) higher inhibition of protein denaturation (57.89%−87.65%) and (55.36%−83.58%) in comparison to control nanoemulsion sample (54.67%−80.28%) and flower extract (51.56%−79.36%), respectively. Due to these biological activities, the WFNE3 nanoemulsion sample could be scaled up to the industrial level for the formulation of varied types of functional foods.

Comparison of Emulsion Stabilizers: Application for the Enhancement of the Bioactivity of Lemongrass Essential Oil

“…Furthermore, conflicting findings also emerge regarding the mechanism underlying the antimicrobial activity of nanoemulsion. For instance, some studies reported that the remarkable antimicrobial activity of nanoemulsion was caused by their increased contact area with the microorganisms, thus an enhancement in the ability of bioactive compounds to penetrate cell membranes and increased accessibility of these compounds [47]. Conversely, other research contends that the antimicrobial efficacy of nanoemulsion can be attributed to the active ingredient instead of its high surface tension or cell wall diffusion activity [45].…”

Medicinal Plant Enriched Metal Nanoparticles and Nanoemulsion for Inflammation Treatment: A Narrative Review on Current Status and Future Perspective

“…A mountain ginseng-based gold nanoparticle was used to prepare NE with another medicinal plant constituting silydianin and investigated potent anti-inflammatory activity in Raw 264.7 cells through MAPK downregulation and NF-κB signaling pathways [83]. The phytocompound of the flower extract of the herbal plant Woodfordia fruticose K synthesized a nanoemulsion and revealed protein denaturation which assured further tissue inflammation and cell stabilization potential in a human red blood cell membrane [84].…”