Overlooked Spherical Nanoparticles Exist in Plant Extracts: From Mechanism to Therapeutic Applications

To date, plant medicine research has focused mainly on the chemical compositions of plant extracts and their medicinal effects. However, the therapeutic or toxic effects of nanoparticles in plant extracts remain unclear. In this study, large numbers of spherical nanoparticles were discovered in some plant extracts. Nanoparticles in Turkish galls extracts were used as an example to examine their pH responsiveness, free radical scavenging, and antibacterial capabilities. By utilizing the underlying formation mechanism of these nanoparticles, a general platform to produce spherical nanoparticles via direct self-assembly of Turkish gall extracts and various functional proteins was developed. The results showed that the nanoparticles retained both the antibacterial ability and intracellular carrier ability of the original protein or catechol. This work introduces a new member of the plant-derived edible nanoparticle (PDEN) family, establishes a simple and versatile platform for mass production nanoparticles, and provides new insight into the formation mechanism of nanoparticles during plant extraction.