Hana Jung

Antioxidant and antiinflammatory activities of cyanidin-3-glucoside and cyanidin-3-rutinoside in hydrogen peroxide and lipopolysaccharide-treated RAW264.7 cells

Cyanidin-3-glucoside (C3G) and cyanidin-3-rutinoside (C3R) are 2 major anthocyanins found in Korean Rubus fruits (blackberries, raspberries, and black raspberries). The antioxidant and antiinflammatory effects of C3G and C3R in RAW264.7 murine macrophage cells were determined. Anthocyanins (5, 10, and 20 μg/mL) significantly (p<0.05) reduced H2O2-induced cytotoxicity in H2O2-stimulated RAW264.7 cells, compared with control cells. Incubation with C3G or C3R significantly (p<0.05) decreased intracellular reactive oxygen species and DNA damage (Hoechst and comet assay), and the cellular ferric reducing antioxidant power also increased, compared with control cells. Nitric oxide production in LPS-stimulated RAW264.7 cells treated with C3G and C3R was reduced by 41.9 and 34.4%, respectively. In addition, LPS-induced prostaglandin E2 production was significantly (p<0.05) inhibited by C3G (51.7%) and C3R (58.6%), compared with LPS-stimulated control cells. Protein expressions of iNOS and COX-2 decreased in cells treated with anthocyanins. Anthocyanins down-regulated NF-κB expression and up-regulated I-κB expression in LPS-treated macrophages.

Anthocyanins in Rubus fruits and antioxidant and anti-inflammatory activities in RAW 264.7 cells

Antioxidant and anti-inflammatory activities of ethanol extracts (E) and anthocyanin fractions (AF) from the 3 Rubus fruits blackberries, Korean raspberries, and black raspberries (BR) produced in Korea were determined. BR contained the highest levels of total polyphenols, flavonoids, anthocyanins, and the highest antioxidant activity. E and AF protected RAW 264.7 cells against H2O2-induced cytotoxicity. AF at 20 µg/mL significantly (p<0.05) decreased intracellular ROS levels (39.1-43.5%) and increased SOD (7.1-35.9%) and GPx (7.5-48.6%) activities in H2O2-treated RAW 264.7 cells, compared with controls. AF also increased Nrf2 protein expression. All AF significantly (p<0.05) reduced H2O2-induced DNA oxidation, compared with controls. AF suppressed NO (32.4-42.9%) and PGE2 (17.4-49.0%) production in LPS-stimulated RAW 264.7 cells along with a decrease in LPS-induced iNOS and COX-2 protein expressions. AF significantly (p<0.05) down-regulated NF-κB expression, compared with controls, via inhibition of I-κBα degradation in LPS-stimulated RAW 264.7 cells.

Bioconversion of Cyanidin-3-Rutinoside to Cyanidin-3-Glucoside in Black Raspberry by Crude α-L-Rhamnosidase from Aspergillus Species.

Cyanidin-3-glucoside (C3G) has been known to be more bioavailable than cyanidin-3- rutinoside (C3R), the most abundant anthocyanin in black raspberry (Rubus occidentalis). The aim of this study was to enhance the bioavailability of anthocyanins in black raspberry by cleaving L-rhamnose in C3R using crude enzyme extracts (CEEs) from Aspergillus usamii KCTC 6956, A. awamori KCTC 60380, A. niger KCCM 11724, A. oryzae KCCM 12698, and A. kawachii KCCM 32819. The enzyme activities of the CEEs were determined by a spectrophotometric method using rho-nitrophenyl-rhamnopyranoside and rho-nitrophenyl-glucopyranoside. The CEE from A. usamii had the highest α-L-rhamnosidase activity with 2.73 U/ml at 60°C, followed by those from A. awamori and A. niger. When bioconversion of C3R to C3G in black raspberry was analyzed by HPLC-DAD, the CEEs from A. usamii and A. awamori hydrolyzed 95.7% and 95.6% of C3R to C3G, respectively, after 2 h incubation. The CEEs from A. kawachii and A. oryzae did not convert C3R to C3G in black raspberry.

Antioxidant activities of sea buckthorn leaf tea extracts compared with green tea extracts

The polyphenol, flavonoid, and ascorbic acid contents of sea buckthorn leaf tea extracts, along with antioxidant activities, were compared with green tea extracts under different extraction conditions. Sea buckthorn leaf tea and green tea were extracted using water (SW, GW) and ethanol at room temperature (SE, GE), respectively, and at 80°C (SWH, GWH, SEH, and GEH, respectively). GEH, GWH, SE, and SEH contained more antioxidant compounds and higher activities, and SWH, SEH, GWH, and GEH had elevated antioxidant enzyme activity levels in H2O2-treated RAW264.7 cells. Cells treated with SWH and SEH showed elevated expression of nuclear factor (erythroid-derived 2)-like 2 and maintained the cell glutathione (GSH)/glutathione disulfide (GSSG) ratio at levels similar to H2O2-untreated controls.

Black Raspberry Seed Oil Improves Lipid Metabolism by Inhibiting Lipogenesis and Promoting Fatty-Acid Oxidation in High-Fat Diet-Induced Obese Mice and db/db Mice

The objective of this study was to evaluate the beneficial effect of α-linolenic acid-rich black raspberry seed (BRS) oil on lipid metabolism in high-fat diet (HFD)-induced obese and db/db mice. Five-week-old C57BL/6 mice were fed diets consisting of 50% calories from lard, 5% from soybean, and 5% from corn oil (HFD), or 50% calories from lard and 10% from BRS oil (HFD + BRS oil diet) for 12 weeks. Six-week-old C57BL/KsJ-db/db mice were fed diets consisting of 16% calories from soybean oil (standard diet), 8% from soybean, and 8% from BRS oil, or 16% from BRS oil for 10 weeks. The BRS oil diets lowered the levels of triacylglycerol, nonesterified fatty acids, and total cholesterol in serum and liver of both of the obese and db/db mice as compared with the HFD and standard diet, respectively. mRNA levels of lipogenesis markers including cluster of differentiation 36, fatty-acid-binding protein 1, sterol regulatory element binding protein 1c, fatty-acid synthase, and solute carrier family 25 member 1 in the liver of the BRS oil groups were lower than those in the liver of the HFD and standard groups in the obese and db/db mice, respectively. On the other hand, fatty-acid oxidation markers including carnitine palmitoyltransferase 1A, acyl-CoA dehydrogenase, hydroxylacyl-CoA dehydrogenase α, and acyl-CoA oxidase in the liver of the BRS oil groups were higher than those in the liver of the HFD and standard groups in the obese and db/db mice, respectively. Peroxisome proliferator-activated receptor α mRNA and protein levels increased in the liver and epididymal adipose tissue of the obese and db/db mice fed BRS oil compared with HFD and standard diet, respectively. BRS oil might improve lipid metabolism by inhibiting lipogenesis and promoting fatty-acid oxidation in HFD-induced obese and db/db mice.