Arsenic album 30C exhibits crystalline nano structure of arsenic trioxide and modulates innate immune markers in murine macrophage cell lines

Macrophages are associated with innate immune response and M1-polarized macrophages exhibit pro-inflammatory functions. Nanoparticles of natural or synthetic compounds are potential triggers of innate immunity. As 2 O 3 is the major component of the homeopathic drug, Arsenic album 30C.This has been claimed to have immune-boosting activities, however, has not been validated experimentally. Here we elucidated the underlying mechanism of Ars. alb 30C-mediated immune priming in murine macrophage cell line. Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) used for the structural analysis of the drug reveals the presence of crystalline As 2 O 3 nanoparticles of cubic structure. Similarly, signatures of M1-macrophage polarization were observed by surface enhanced Raman scattering (SERS) in RAW 264.7 cells with concomitant over expression of M1 cell surface marker, CD80 and transcription factor, NF-κB, respectively. We also observed a significant increase in pro-inflammatory cytokines like iNOS, TNF-α, IL-6, and COX-2 expression with unaltered ROS and apoptosis in drug-treated cells. Enhanced expression of Toll-like receptors 3 and 7 were observed both in transcriptional and translational levels after the drug treatment. In sum, our findings for the first time indicated the presence of crystalline As 2 O 3 cubic nanostructure in Ars. alb 30C which facilitates modulation of innate immunity by activating macrophage polarization.