Reactive oxygen species (ROS/RNS) are produced during inflammation and elicit protein modifications, but the immunological consequences are largely unknown.,Gas plasma technology capable of generating an unmatched variety of ROS/RNS is deployed to mimic inflammation and study the significance of ROS/RNS modifications using the model protein chicken ovalbumin (Ova vs oxOva).,Dynamic light scattering and circular dichroism spectroscopy reveal structural modifications in oxOva compared to Ova.,T cells from Ova‐specific OT‐II but not from C57BL/6 or SKH‐1 wild type mice presents enhanced activation after Ova addition.,OxOva exacerbates this activation when administered ex vivo or in vivo, along with an increased interferon‐gamma production, a known anti‐melanoma agent.,OxOva vaccination of wild type mice followed by inoculation of syngeneic B16F10 Ova‐expressing melanoma cells shows enhanced T cell number and activation, decreased tumor burden, and elevated numbers of antigen‐presenting cells when compared to their Ova‐vaccinated counterparts.,Analysis of oxOva using mass spectrometry identifies three hot spots regions rich in oxidative modifications that are associated with the increased T cell activation.,Using Ova as a model protein, the findings suggest an immunomodulating role of multi‐ROS/RNS modifications that may spur novel research lines in inflammation research and for vaccination strategies in oncology.,Successful vaccination requires increased immunogenicity of antigens.,Cold physical plasmas produce reactive oxygen and nitrogen species capable of eliciting oxidative protein modifications.,Oxidation of ovalbumin (Ova) shows enhanced T cell activation, elevated numbers of antigen‐presenting cells, and decreases tumor burden in vivo upon vaccination.
Recent studies claimed the important role of cold atmospheric plasma (CAP) with nanotechnology in cancer treatments.,In this study, silymarin nanoemulsion (SN) was used along with air CAP as therapeutic agent to counter human melanoma.,In this study, we examined the combined treatment of CAP and SN on G-361 human melanoma cells by evaluating cellular toxicity levels, reactive oxygen and nitrogen species (RONS) levels, DNA damage, melanoma-specific markers, apoptosis, caspases and poly ADP-ribose polymerase-1 (PARP-1) levels using flow cytometer.,Dual-treatment effects on the epithelial-mesenchymal transition (EMT), Hepatocyte growth factor (HGF/c-MET) pathway, sphere formation and the reversal of EMT were also assessed using western blotting and microscopy respectively.,SN and plasma-activated medium (PAM) were applied on tumor growth and body weight and melanoma-specific markers and the mesenchymal markers in the tumor xenograft nude mice model were checked.,Co-treatment of SN and air CAP increased the cellular toxicity in a time-dependent manner and shows maximum toxicity at 200 nM in 24 h.,Intracellular RONS showed significant generation of ROS (< 3 times) and RNS (< 2.5 times) in dual-treated samples compared to control.,DNA damage studies were assessed by estimating the level of γ-H2AX (1.8 times), PD-1 (> 2 times) and DNMT and showed damage in G-361 cells.,Increase in Caspase 8,9,3/7 (> 1.5 times), PARP level (2.5 times) and apoptotic genes level were also observed in dual treated group and hence blocking HGF/c-MET pathway.,Decrease in EMT markers (E-cadherin, YKL-40, N-cadherin, SNAI1) were seen with simultaneously decline in melanoma cells (BRAF, NAMPT) and stem cells (CD133, ABCB5) markers.,In vivo results showed significant reduction in SN with PAM with reduction in tumor weight and size.,The use of air CAP using μ-DBD and the SN can minimize the malignancy effects of melanoma cells by describing HGF/c-MET molecular mechanism of acting on G-361 human melanoma cells and in mice xenografts, possibly leading to suitable targets for innovative anti-melanoma approaches in the future.,The online version of this article (10.1186/s12964-019-0360-4) contains supplementary material, which is available to authorized users.