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AIM:To discuss the effects of different concentrations of tetramethylpyrazine (TMP), an active constituent of Chinese herb, on damaged Shandonghuman corneal epithelial cell (SDHCEC) induced by hydrogen peroxide.METHODS:We detected the combined effects of TMP with concentrations ranging from 4 mg/mL to 0.03 mg/mL and 800 μM hydrogen peroxide on SDHCEC. The methyl thiazolyl tetrazolium (MTT) assay was processed at 3, 6 and 12h separately while the detection of cell apoptosis at 6h only by flow cytometry.RESULTS:The viability of SDHCEC with 0.5 mg/mL, 0.25 mg/mL, 0.125 mg/mL and 0.06 mg/mL TMP joint with 800 μM hydrogen peroxide at 3h and 6h was significantly higher than that with 800 μM hydrogen peroxide only, P＜0.05. However, except 0.25 mg/mL, TMP with other concentrations joint with 800 μM hydrogen peroxide at 12h could not significantly inhibit decreased SDHCEC viability induced by 800 μM hydrogen peroxide. At 12h, TMP of 0.5 mg/mL, 0.25 mg/mL, 0.125 mg/mL and 0.06 mg/mL could significantly inhibit SDHCEC early apoptosis induced by 800 μM hydrogen peroxide, most remarkable at 0.25 mg/mL TMP, P＜0.05.CONCLUSION:Our results suggested that hydrogen peroxide can induce apoptosis related damage to SDHCEC. TMP can protect SDHCEC from the damage, and the protective effects may be associated with its anti-apoptosis mechanism.

The photocatalytic depolymerization of Dagang vacuum residue (DVR) was carried out with H2O2 over TiO2 in a photochemical reactor. Most of the organic matter in DVR was converted into oxygen-containing organic compounds. The yields of carboxylic acids, oxalates, epoxy compounds, and hydroxyl compounds from DVR oxidation are 40.6%, 36.4%, 17.86%, and 13.5%, respectively. In addition, the oxidation causes significant decrease in viscosity and chromaticity of DVR. The related reaction mechanisms are discussed according to the experimental results. [ABSTRACT FROM AUTHOR]

The photocatalytic depolymerization of Dagang vacuum residue (DVR) was carried out with H2O2 over TiO2 in a photochemical reactor. Most of the organic matter in DVR was converted into oxygen-containing organic compounds. The yields of carboxylic acids, oxalates, epoxy compounds, and hydroxyl compounds from DVR oxidation are 40.6%, 36.4%, 17.86%, and 13.5%, respectively. In addition, the oxidation causes significant decrease in viscosity and chromaticity of DVR. The related reaction mechanisms are discussed according to the experimental results. [ABSTRACT FROM AUTHOR]