Raman spectral changes of Artemisinin-induced Raji cells apoptosis

Though it has been reported that Artemisinin (ART), a traditional Chinese herb extract medicine, might inhibit the transferrin receptor of tumor cells to transfer iron and induce cell apoptosis, it remains controversial about the mechanism of ART-induced cell apoptosis. In this study, the single-cell Raman spectral data during ART-induced Raji cells apoptosis were acquired by Micro-Raman spectroscopy. Correspondingly, Raman spectral data during Dexamethasone (DEX)-induced Raji cells apoptosis were also presented. The obtained result revealed that peaks at 1303 and 1655 cm−1 assigned to proteins and the peak at 785 cm−1 assigned to the symmetric stretching vibration mode of OPO of DNA were changed in intensity in ART-treated cells relative to untreated cells. One possible reason was that ART played a role to inhibit the receptors generation of Raji cells during apoptosis. Moreover, by combining Raman spectral differences and principal component analysis (PCA), it was presented that the main biochemical changes of ART-induced cell apoptosis were come from the content and structure changes of proteins and nucleic acids, which were different from DEX-induced DNA changes, indicating that the mechanism of ART-induced cell apoptosis might be different with DEX-induced DNA damaging cell apoptosis. Importantly, these results also showed that PCA based Raman spectral analysis should be a better approach to exhibit the drugs-induced cell apoptosis. Moreover, this method will provide a useful tool to construct a biological model of cell apoptosis in vitro for the clinical treatment and anticancer drug research.