Low pH-Based Method to Increase the Yield of Plant-Derived Nanoparticles from Fresh Ginger Rhizomes

(1), 4456.). Herein, we report a 4-5-fold higher ginger PDNP recovery when PEG precipitation was carried out in low pH conditions (pH 4 and 5). Low pH-derived ginger PDNPs were smaller in size without an overt change in zeta potential. The spontaneous intracellular entry and protection against oxidative stress in A431 cells were similar between ginger PDNPs purified under low, neutral, and alkaline pH. Low-pH purified ginger PDNPs had higher levels of total polyphenolic content compared to PDNPs purified under neutral and alkaline pH. Recently, ginger PDNP-derived microRNAs have been shown to exhibit cross-kingdom regulation by targeting human, gut microbiome, and viral transcripts. Using qRT-PCR, we also verified the presence of miRNAs that were predicted to target SARS-CoV-2 in ginger PDNPs purified under low pH. Thus, we have developed a method to purify ginger PDNPs in high yields by using low-pH conditions without affecting the major bioactive contents of PDNPs.