Exosome-Like Nanoparticles from Indonesian Red and Emprit Ginger Varieties Suppress LPS-Induced IL-6 Production in RAW 264.7 Macrophages.

Abstract

Purpose: Studies have shown the potential of exosomes as therapeutic agents with anti-inflammatory properties. However, the clinical application of mammalian-derived exosomes is hindered by mass production challenges and strict regulations. Plant-derived exosome-like nanoparticles (PELNs) are a more economical alternative possessing a similar therapeutic potential. Ginger is a readily available plant with components that are clinically proven to inhibit inflammation. Therefore, it is interesting to investigate the potential of red ginger and emprit ginger, cultivated varieties in Indonesia possessing the most potent anti-inflammatory activities, as a PELN source for anti-inflammatory therapy.

Methods: In this work, PELNs from the rhizomes of red ginger (RG-ELN) and emprit ginger (EG-ELN) were obtained through differential centrifugation and polymer precipitation using PEG6000. The PELNs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and bicinchoninic acid assay. Their internalization and effect on RAW 246.7 cell viability were also assessed. The anti-inflammatory potential of PELNs was investigated by assessing interleukin 6 (IL-6) expression of lipopolysaccharide (LPS)-stimulated macrophages treated with RG-ELN and EG-ELN.

Results: Both RG-ELN and EG-ELN exhibited cup-shaped morphologies with average sizes of 195.83±1.35 and 194.40±8.40 nm, respectively. Both PELNs can be internalized within 2 h and did not significantly affect RAW 264.7 cell viability after 24 h. The reverse transcription quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay results indicated a significantly lower expression and secretion of IL-6 in the macrophage cells pre-treated with RG-ELN and EG-ELN.

Conclusion: The RG-ELN and EG-ELN samples were successfully obtained through the polymer precipitation method, as confirmed by the TEM and DLS results which aligned with typical PELN characteristics. The pre-treatment of RG-ELN and EG-ELN to activated RAW 264.7 cells decreased the pro-inflammatory cytokine IL-6 expression relative to activated controls.