Effects of wogonin on the mechanism of melanin synthesis in A375 cells.

The present study aimed to investigate the effect of wogonin on the mechanism of melanin synthesis in the A375 melanoma cell line. A375 cells, cultured in vitro, were treated with wogonin and the activity of tyrosinase (TYR) and melanin synthesis were examined via MTT assay, L-dopa oxidation assay and an NaOH lysis assay. Protein expression levels of TYR and c-Jun N-terminal kinase (JNK) were examined via western blotting. mRNA expression levels of TYR, tyrosinase related protein (TRP)-1, TRP-2, extracellular signal-regulated kinase (ERK)-1, ERK-2 and JNK-2 were analyzed by reverse transcription-quantitative polymerase chain reaction. Furthermore, the effect of wogonin on estrogen receptor inhibitor (ICI182780) and ERK pathway inhibitor (U0126) was investigated. Safe doses of wogonin (10, 1, 10-1, 10-2 or 10-3 µmol/l) significantly inhibited melanin synthesis and TYR activity (P<0.05). Wogonin (10 µmol/l) inhibited the protein expression levels of TYR, JNK and mRNA expression levels of TYR, TRP-1, TRP-2, ERK-1, ERK-2, JNK-2 in A375 cells (P<0.01). The estrogen receptor inhibitor, ICI182780, and MEK inhibitor, U0126, significantly reversed the effects of wogonin on protein and mRNA expression levels of TYR, TRP-1, TRP-2, ERK-1, ERK-2 and JNK-2 (all P<0.01). To conclude, the present study identified that wogonin is able to inhibit the synthesis of melanin in A375 cells, through inhibiting protein and mRNA expression levels of TYR, TRP-1, and TRP-2, and ERK1, ERK2 and JNK2, respectively.

Preliminary study of urine metabolism in type two diabetic patients based on GC-MS.

OBJECTIVE: Comparative study of type 2 diabetes and healthy controls by metabolomics methods to explore the pathogenesis of Type II diabetes. METHODS: Gas chromatography - mass spectrometry (GC-MS) with a variety of multivariate statistical analysis methods to the healthy control group 58 cases, 68 cases of Type II diabetes group were analyzed. Chromatographic conditions: DB-5MS column; the carrier gas He; flow rate of 1 mL·min(-1), the injection volume 1 uL; split ratio is 100: 1. MS conditions: electron impact (EI) ion source, an auxiliary temperature of 280°C, the ion source 230°C, quadrupole 150°C; mass scan range 30~600 mAu. RESULTS: Established analytical method based on urine metabolomics GC-MS of Type II diabetes, determine the urine succinic acid, L-leucine, L-isoleucine, tyrosine, slanine, acetoace acid, mannose, L-isoleucine, L-threonine, Phenylalanine, fructose, D-glucose, palmi acid, oleic acid and arachidonic acid were significantly were significantly changed. CONCLUSION: Based on metabolomics of GC-MS detection and analysis metabolites can be found differences between type 2 diabetes and healthy control group, PCA diagram can effectively distinguish Type II diabetes and healthy control group, with load diagrams and PLS-DA VIP value metabolite screening, the resulting differences in metabolic pathways involved metabolites, including amino acid metabolism, lipid metabolism, glucose metabolism and energy metabolism.

Effects of bavachin and its regulation of melanin synthesis in A375 cells.

The aim of the present study was to investigate the effect of bavachin treatment on A375 cells and the regulation of melanin synthesis. The cultured A375 cells in vitro were treated with bavachin; and the effect of bavachin on cell activity, tyrosinase (TYR) activity and melanin synthesis were respectively tested by the MTT assay, L-dopa oxidation assay and the NaOH lysis assay. The expression levels of TYR and c-Jun N-terminal kinases (JNK) proteins were tested by western blot analysis. The expression levels of TYR, tyrosinase-related protein-1 (TRP-1), TRP-2, extracellular signal-regulated kinase 1 (ERK1), ERK2 and JNK2 mRNA were tested by the reverse transcription-polymerase chain reaction assay. Simultaneously, the effect of estrogen receptor inhibitor (ICI182780) and ERK pathway inhibitor (U0126) was also tested on A375 cells following bavachin. The safe dose of bavachin significantly inhibited melanin synthesis and TYR activity. Bavachin (10 µmol/l) inhibited the expression of TYR and JNK proteins, and the expression of TYR, TRP-1, TRP-2, ERK1, ERK2 and JNK2 mRNA in A375 cells. ICI182780 and U0126 could significantly reverse the bavachin treatment on the protein expression levels and the mRNA expression of TYR, TRP-1, TRP-2, ERK1, ERK2 and JNK2. In conclusion, bavachin inhibited the synthesis of melanin on A375 cells by inhibiting the protein and mRNA expression of TYR, TRP-1, TRP-2, ERK1, ERK2 and JNK2.