Effect of Shenqin biochemical extract on hypoxia-inducible factor-1α expression in ultraviolet B-irradiated HaCaT cells.

Hypoxia-inducible factor-1α (HIF-1α) is considered the main transcriptional regulator of the hypoxia-specific cellular and developmental response. This study was performed to investigate the effect of Shenqin biochemical extract (SQBE) on HIF-1α expression in ultraviolet B (UVB)-irradiated HaCaT cells and the possible action mechanisms of SQBE against UVB-induced skin cancer. HaCaT cells in logarithmic growth phase were seeded in Dulbecco's modified Eagle's medium with 10% fetal bovine serum, and conventionally cultured at 37°C with 5% CO2. Cells were divided into control group (administered the same amounts of dimethyl sulfoxide), SQBE1 group (12.5 µg/mL SQBE), SQBE2 group (25.0 µg/mL SQBE), and SQBE3 group (50.0 µg/mL SQBE). Four hours post administration, the control and treatment groups were irradiated with UVB (0, 20, 40, and 60 mJ/cm2). After 24 h, cell survival rate was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Expression levels of HIF-1α mRNA and protein were detected by polymerase chain reaction and western blotting, respectively. SQBE-treated, UVB-irradiated cells had improved survival rates. This increase was most significant in SQBE3 group (P < 0.01), which also had effectively reduced expression of intracellular HIF-1α mRNA and protein. Hence, SQBE had a protective effect on UVB-irradiated HaCaT cells and inhibited the UVB irradiation-induced expression of HIF-1α. This indicates that SQBE could prevent the occurrence of UVB radiation-induced skin cancer.

Effect of sinomenine on the expression of rheumatoid arthritis fibroblast-like synoviocytes MyD88 and TRAF6.

The effect of sinomenine (SIN) on the toll-like receptor (TLR) signal transduction pathway as well as the expression of myeloid differentiation factor 88 (MyD88) and tumor necrosis factor (TNF) receptor-associated factor-6 (TRAF6) was investigated. SIN inhibition of rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) proliferation and RA cartilage and subchondral bone destruction was also investigated. RA-FLS were cultured in vitro and the intracellular alkaline phosphatase (ALP) activity was determined in order to obtain the optimal drug concentration. The rate of cell proliferation was determined. Fluorescence quantitative polymerase chain reaction (PCR) was applied to determine the MyD88 and TRAF-6 gene expression and western blot was used to detect the MyD88 and TRAF-6 protein expression. The ALP activity in the SIN groups was lower than that in the control group, among which the 0.5 mM SIN group had the lowest ALP activity (P < 0.01). The rate of RA-FLS proliferation detected by CCK-8 assay in the 0.5-mM SIN group was lower than that in the control group (P < 0.01) and was the highest 4 days after SIN induction. Gene and protein expression of MyD88 and TRAF-6 were downregulated significantly in the 0.5-mM SIN group compared to that in the control group (P < 0.01). SIN effectively inhibited MyD88 and TRAF-6 expression in RA-FLS, which may be one of the important molecular mechanisms involved in RA treatment and prevention of cartilage and subchondral bone destruction.