Biomedical subjects

Zhen-yu Chen

Publications and source records attributed to Zhen-yu Chen.

5 recordsLinked to original sources

PubMed2006

[Changes of maternal plasma and umbilical cord plasma inhibin and epidermal growth factor in patients with hypertensive disorder complicating pregnancy].

OBJECTIVE: To study the levels of inhibin (INH) and epidermal growth factor (EGF) in maternal plasma and umbilical cord plasma of patients with hypertensive disorder complicating pregnancy, and to explore their influence on the disease and fetal growth. METHODS: Enzyme linked immunosorbent assay (ELISA) was used to detect maternal and umbilical cord plasma INH and EGF levels in 65 patients with hypertensive disorder complicating pregnancy (test groups) and 21 normal pregnant women (control group). RESULTS: Plasma level of INH in test groups (499 +/- 52) ng/L was significantly higher than that (421 +/- 36) ng/L in control group (P < 0.01); however, the umbilical cord plasma level of INH had no significant difference (P > 0.05). Plasma level of EGF in test groups (408 +/- 60) ng/L was significantly lower than that (463 +/- 87) ng/L in control group (P < 0.05), also there was significant difference in umbilical cord plasma level of two groups (232 +/- 99) ng/L vs (380 +/- 97) ng/L (P < 0.01). The level of EGF in umbilical cord blood was positively correlated with newborn's body weight and placental weight. CONCLUSIONS: Plasma levels of INH and EGF in pregnancy women are related with hypertensive disorder complicating pregnancy. EGF level of umbilical cord blood affects the growth of fetus and placenta.

Adult↗

PubMed2005

Hydroxychalcones exhibit differential effects on XRE transactivation.

Chalcones are phenolic compounds that can be isolated from plants. Previous studies have described some pharmacological applications for these compounds. Making use of our established reporter gene system, we determined the effect of five hydroxychalcones--2-hydroxychalcone, 2'-hydroxychalcone, 4-hydroxychalcone, 4,2',4'-trihydroxychalcone, and 3,4,2',4'-tetrahydroxychalcone--on the cellular xenobiotic responsive element (XRE)-transactivation. The interference of chalcones acting against polycyclic aromatic hydrocarbon (PAH)-DNA binding was also examined. Enzyme inhibition assays of cytochrome P450 (CYP) 1A1 and CYP1B1 were initially performed on recombinant protein expressed in insect microsomes. 2'-Hydroxychalcone and 2-hydroxychalcone were the most effective among the tested hydroxychalcones. The two hydroxychalcones had comparable IC50 values for CYP1A1 and CYP1B1, which were determined to be at the micromolar and submicromolar range, respectively. However, reporter gene assays indicated that 2'-hydroxychalcone suppressed XRE-transactivation, whereas 2-hydroxychalcone induced it when 7,12-dimethylbenz[a]anthracene (DMBA) was co-administered. In the absence of DMBA, 10 microM 2-hydroxychalcone and 2'-hydroxychalcone increased XRE-transactivation by 18- and 2.5-fold, respectively, while other chalcones did not significantly alter the response. Cultures treated with the two hydroxychalcones also displayed separate trends in ethoxyresorufin-O-deethylase (EROD) activity and DMBA-DNA covalent binding. In summary, the present study illustrated that the inhibition of hydroxychalcone on CYP1 enzymes and XRE-transactivation was affected by the position and number of hydroxyl groups in its structure.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2004

[Isolation and elucidation of antioxidant constituents from acetone extract in root of Scutellaria rehderiana].

OBJECTIVE: To isolatate and elucidate the antioxidant constituents from acetone extract of Scutellaria rehderiana. METHOD: Chemical constituents were isolated by several column chromatographies and their structures were elucidated on the basis of standard compounds and spectral analysis. RESULT: Five compounds, oroxylin A, wogonin, baicalein, ganhuangenin, ganhuangemin were isolated from acetone extract of S. rehderiana. Baicalin was obtained from methanol extract of S. rehderiana. CONCLUSION: Ganhuangemin was isolated from the plant for the first time. Baicalein and ganhuangenin have stronger antioxidant activity than that of BHT (butylated hydroxytoluene).

Antioxidants↗

PubMed2002

Baicalein and genistein display differential actions on estrogen receptor (ER) transactivation and apoptosis in MCF-7 cells.

Genistein is a soy isoflavone that has attracted much attention for its chemopreventive properties. Baicalein is a flavone found in Scutellaria species, and its structure is analogous to that of genistein. We examined the two flavones' antiestrogenicity by using a transient transfection model. Our results indicated that baicalein could suppress 17beta-estradiol-induced transactivation in cells expressing estrogen receptor alpha, whereas no antagonistic activity was seen in genistein. Cell death assay and flow cytometry analysis demonstrated that baicalein was a stronger apoptosis inducing agent than genistein. Considering all the criteria tested, baicalein could be a better chemopreventive agent than genistein.

Antineoplastic Agents↗

PubMed2002

Baicalein inhibits DMBA-DNA adduct formation by modulating CYP1A1 and CYP1B1 activities.

Flavonoids are phenolic compounds isolated from plants, and several of them like genistein and quercetin, have been documented to be effective in preventing cancer. Baicalein, a flavonoid extracted from the root of Scutellaria species, is widely used as a health supplement and herbal medicine in Asian countries. In this study, the chemopreventive effect of baicalein on 7,12-dimethylbenz[a]anthracene (DMBA)-induced DNA damage was evaluated in an established cell culture model. In a preliminary screening, baicalein was identified to be a strong inhibitor to EROD activities induced by DMBA in MCF-7 cells. Subsequent enzyme kinetic analysis revealed that baicalein was a competitive inhibitor to EROD, and CYP1A1 and CYP1B1 gene expressions were also determined. Baicalein could reduce the CYP1A1/1B1 mRNA expressions induced by DMBA, and the mRNA abundance of CYP1A1 appeared to be more responsive than that of CYP1B1. A XRE-luciferase gene reporter assay indicated that AhR transactivation was suppressed. Since CYP1A1/1B1 were responsible for the biotransformation of polycyclic aromatic hydrocarbons, baicalein also demonstrated its ability to reduce DMBA-DNA adduct formation in MCF-7 cells. This study suggested that the natural occurring baicalein could be an agent preventing carcinogen-DNA adduct formation.

9,10-Dimethyl-1,2-benzanthracene↗