Synthesis of vitamin-selenium complex and its effects on proteins and tumor cells

A selenium-vitamin P complex (SEVP) was synthesized and its structure was determined by IR, LC-MS and (1)H NMR. Its biological effects on bovine serum albumin (BSA) and human colon carcinoma tumor cells were studied by molecular spectra, MTT and flow cytometry. The interaction of SEVP and BSA was discussed by fluorescence quenching method and Förster non-radiation energy transfer theory. The thermodynamic parameters ΔH(θ), ΔG(θ), ΔS(θ) at different temperatures were calculated and the results indicate the interaction is an exothermic as well as entropy-driven process. Hydrogen bond and electrostatic force played major role in the reaction. The binding geometry and conformation changes of BSA were investigated by fluorescence probe technique and circular dichroism (CD) spectra. The effects of SEVP on human colon carcinoma tumor cells HT29 were tested by MTT method and flow cytometry (FCM). The MTT results show the proliferation of HT29 tumor cells were inhibited by SEVP and the inhibition was associated with dose and time. The FCM analysis disclosed SEVP interrupted the DNA synthesis of tumor cells at S phase.