Susceptibility of epithelial tumour cell lines to hyperthermia.

BACKGROUND: Human skin or mucosa exposes cells to both an internal and exogeneous thermal environment and the cells survive within a certain range of temperature. Exogeneous hyperthermia has been applied for the treatment of various types of cancers, fungal disease, and warts. OBJECTIVES: To determine whether different cellular components in the skin adapt to hyperthermic conditions differentially and further elucidate the mechanisms involved. MATERIALS & METHODS: Cell lines derived from normal and tumour epithelial cells were treated with hyperthermic conditions and tested for viability (using an MTS assay), apoptosis (using a FITC-conjugated annexin V apoptosis detection kit), and changes in intracellular calcium (using a calcium-sensitive fluorescent single-wavelength dye, Fluo-4 AM). RESULTS: Thermo-resistance of different cell types was different when cells were subjected to heat at 45̊C for 30 minutes. Stronger effects of hyperthermia were noted on cell viability and apoptosis in epidermal cells relative to their malignant counterparts, except for cell lines harbouring human papillomavirus (HPV). Hyperthermia had a much greater effect on cell viability and apoptosis in a HPV-negative cell line compared to HPV-positive cell lines. We further found that hyperthermia treatment resulted in a strong calcium influx which led to apoptotic cells. However, no obvious increase in apoptosis was observed in cells treated with the CRAC channel selective inhibitor, BTP2, before application of hyperthermia in all cell types, except three cervical cell lines harbouring HPV. CONCLUSION: We propose that hyperthermia results in a CRAC-related strong calcium influx which induces apoptosis, with the exception of HPV-positive cells.

[Determination of ferulic acid in Fuan oral liquid by high-performance capillary electrophoresis].

OBJECTIVE: To establish a quality control method of Fuan oral liquid. METHODS: High-performance capillary electrophoresis (HPCE) was used to determine the content of feruild acid in Herba taraxaci, and thin-layer chromatography (TLC) was performed to identify Herba taraxaci and Bupleurum chinense. The condition of HPCE was optimized with a fuse silica capillary tube (70 microm x 60 cm) and 20 mmol/L sodium tetraborate buffer (pH9.18) at a constant voltage of 12 kV and temperature at 25 degrees celsius;, with the detection wavelength at 313 nm. RESULTS: Clear spots were displayed on TLC. The calibration curve was linear in the range of 8-40 microg/ml for ferulic acid (Y=360.5-207.4, r=0.9997, n=5). The average recovery rate exceeded 95% with a RSD<3% (n=3). CONCLUSION: This method is simple and specific with a good reproducibility for quality control of Fuan oral liquid.

[Qualitative fingerprint and quantitative determination of caffeic acid in compound dandelion enema].

OBJECTIVE: To establish a qualitative and quantitative reversed-phase high-performance liquid chromatography (RP-HPLC) with fingerprinting technique for quality control of compound dandelion enema. METHODS: HPLC was utilized for quality assessment of 10 batches of samples. RP-HPLC analysis was performed on a Hypersil BDS C18 column (4.6 mm x 250 mm, 5 microm) with the mixture of acetonitrile (A) and potassium phosphate solution (B) (pH3.2) as the mobile phase in gradient mode. The concentrations of solvent A were 10%, 80% and 80% at 0, 38 and 40 min, respectively. The column temperature was set at 35 degrees C, the flow rate at 0.7 ml/min and the detection wavelength at 254 nm. RESULTS: HPLC fingerprinting was established from the 10 batches, and the data showed 23 characteristic peaks in the compound dandelion enema for use as index peaks for qualitative identification. Comparison of the retention time and the on-line UV spectra of the samples with the chemical standards identified peaks 3, 4 and 8 as protocatechualdehyde, caffeic acid and ferulic acid, respectively. The contents of caffeic acid in the compound dandelion enema ranged between 63.7 and 136.8 microg/ml. CONCLUSION: High specific chromatographic fingerprinting and quantitative measurement of caffeic acid allows rigorous quality control of compound dandelion enema.