Tae-Youl Ha

Dietary resveratrol alters lipid metabolism-related gene expression of mice on an atherogenic diet

BACKGROUND/AIMS Resveratrol, a polyphenolic activator of the silent information regulation 2 homolog 1 (SIRT1), is known to extend lifespan and improve metabolic disease. The aim of the present study is to test whether resveratrol protects against metabolic steatohepatitis through the modulation of lipid metabolism-related genes. METHODS We used a mouse model in which steatohepatitis can be induced by an atherogenic diet (Ath diet) to evaluate the effects of resveratrol on steatotic hepatitis and hepatic gene expression. RESULTS The Ath diet induced excessive weight gain, hepatomegaly, dyslipidemia, and steatohepatitis after 8 weeks. The addition of resveratrol protected against Ath diet-induced changes and also alleviated steatohepatitis. Whole-genome expression analysis revealed that an Ath diet altered the hepatic expression of genes involved in lipid metabolism, and the addition of resveratrol to the diet reversed that effect. Real-time PCR and Western blot analysis confirmed the Ath diet up-regulated the levels of genes related to lipogenesis and down-regulated genes involved in lipolysis. Resveratrol clearly suppressed the Ath diet-induced alterations of the expression of genes related to lipid metabolism. CONCLUSIONS Resveratrol ameliorated dyslipidemia and steatohepatitis induced by the Ath diet, and its beneficial effects were associated with the altered expression of hepatic genes involved in lipid metabolism.

Quercetin Reduces High‐Fat Diet‐Induced Fat Accumulation in the Liver by Regulating Lipid Metabolism Genes

To understand the molecular mechanisms underlying the influence of quercetin on the physiological effects of hyperlipidemia, we investigated its role in the prevention of high‐fat diet (HFD)‐induced obesity and found that it regulated hepatic gene expression related to lipid metabolism. Quercetin supplementation in mice significantly reduced the HFD‐induced gains in body weight, liver weight, and white adipose tissue weight compared with the mice fed only with HFD. It also significantly reduced HFD‐induced increases in serum lipids, including cholesterol, triglyceride, and thiobarbituric acid‐reactive substance (TBARS). Consistent with the reduced liver weight and white adipose tissue weight, hepatic lipid accumulation and the size of lipid droplets in the epididymal fat pads were also reduced by quercetin supplementation. To further investigate how quercetin may reduce obesity, we analyzed lipid metabolism‐related genes in the liver. Quercetin supplementation altered expression profiles of several lipid metabolism‐related genes, including Fnta, Pon1, Pparg, Aldh1b1, Apoa4, Abcg5, Gpam, Acaca, Cd36, Fdft1, and Fasn, relative to those in HFD control mice. The expression patterns of these genes observed by quantitative reverse transcriptase‐polymerase chain reaction were confirmed by immunoblot assays. Collectively, our results indicate that quercetin prevents HFD‐induced obesity in C57B1/6 mice, and its anti‐obesity effects may be related to the regulation of lipogenesis at the level of transcription. Copyright

Estrogenic activities of Psoralea corylifolia L. seed extracts and main constituents

Estrogenic activities of ethanol extract and its active components from Psoralea corylifolia L. were studied using various in vitro assays. The main components from ethanol extract were analyzed to be bakuchiol, psoralen, isobavachalcone, isobavachromene, and bavachinin. In a fractionation procedure, hexane and chloroform fractions showed estrogenic activity in yeast transactivation assay and E-screen assay. In yeast transactivation assay, ethanol extract, hexane, and chloroform fractions showed significantly higher activities at a concentration of 1.0 ng/ml, and bakuchiol at the concentration of 10(-6) M was showed the highest activity, especially, which was higher than genistein at the same concentration. In E-screen assay, cell proliferation of bakuchiol (10(-6) M) showed similar estrogenic activity with genistein (10(-6) M). In ER binding assay, bakuchiol displayed the strongest ER-binding affinity (IC(50) for ERα=1.01×10(-6) M, IC(50) for ERβ=1.20×10(-6) M) and bakuchiol showed five times higher affinity for ERα than for ERβ.

Isolation and Anti-Inflammatory Activity of Bakuchiol from Ulmus davidiana var. japonica

The bark of the root and stem of Ulmus davidiana var. japonica has been used as a traditional Korean medicine to treat inflammatory disorders. This plant reportedly exhibits antioxidant, anticancer, and anti-inflammatory effects. A search for biologically active compounds in U. davidiana var. japonica extracts yielded bakuchiol, which we structurally identified on the basis of spectral data, including two-dimensional nuclear magnetic resonance spectroscopy and distortionless enhancement by polarization transfer. In our study, bakuchiol (50 microM) inhibited lipopolysaccharide-induced nitric oxide and prostaglandin E(2) production in RAW 264.7 macrophages by 53.7% and 84.2%, respectively. These results suggested that bakuchiol is one of the potent anti-inflammatory components of U. davidiana var. japonica.

Comparison of Phytochemical and Antioxidant Activities in Different Color Stages and Varieties of Paprika Harvested in Korea

This study qualitatively and quantitatively analyzed various carotenoids, L-ascorbic acid, and tocopherol and their anti-oxidant properties from four varieties (Special, Chelsea, Cupra, and Fiesta) and three different color stages (green (GP), yellow (YP) and red (RP)) of paprika harvested in Korea. Seven carotenoids were identified, mainly lutein in GP (Special: 4.65±0.84 mg/kg fresh weight (fw)) and YP (Fiesta: 5.19±0.05 mg/kg fw), and capsorubin (3.16±0.35 mg/kg fw) and capsanthin (53.70±6.23 mg/kg fw) in Special of RP. RP was the highest in total carotenoids, L-ascorbic acid, and α-tocopherol contents, while GP was the highest in γ-tocopherol content. RP showed the strongest antioxidant activity (IC 50 =62.40±0.03 µg/mL in an ABTS assay and 182.77±31.74 µg/mL in a DPPH assay). Paprika in different color stages has many phytochemicals even though they have different kinds of carotenoids. Therefore, dietary intake of paprika may be helpful for improving human health.

Ethanol Extract and Saponin of Platycodon grandiflorum Ameliorate Scopolamine-Induced Amnesia in Mice

This study was carried out to examine the effects of ethanol extract (EXPG) and saponin (SAP) from Platycodon grandiflorum on scopolamine-induced amnesia in mice. Fifty male ICR mice were assigned to five groups--normal (normal diet + saline), control (normal diet + scopolamine), EXPG 0.2% (normal diet + 0.2% EXPG + scopolamine), EXPG 0.5% (normal diet + 0.5% EXPG + scopolamine), and SAP 0.02% (normal diet + 0.02% SAP + scopolamine)--and fed each diet ad libitum. After 4 weeks of feeding the appropriate diet, scopolamine (1 mg/kg, i.p.) was given to mice 45 minutes before the passive avoidance and Morris water maze tasks. Both the EXPG groups and the SAP group exhibited significant amelioration of scopolamine-induced amnesia as measured in both the passive avoidance task and the Morris water maze task. Moreover, acetylcholinesterase (AChE) activity and the levels of thiobarbituric acid-reactive substance (TBARS) in the serum and brain of the EXPG groups were lower than those of the control group. These results suggest that EXPG may improve the cognitive deficit caused by scopolamine and that these effects might be due to EXPG mediated by inhibition of AChE activity and inhibition of TBARS.