Optimization of Cyanidin-3-O-galactoside Production from Aronia melanocarpa Elliot from Nonthermal Ultrasonic Extraction Process by Response Surface Methodology

As a nonthermal process, ultrasonic extraction was optimized to obtain 13.21 mg/g of highly bioactive but extremely heat-sensitive cyanidin-3-O-galactoside (C3G) from Aronia melanocarpa Elliot under the following conditions; 75 kHz input frequency, 18.8 °C for the temperature, and 6.0 h process time. This yield was higher than 10.01 mg/g from a conventional juice extraction and was also higher than those from other reported sources. This concentration was proved to be very close to the predicted value of 13.70 mg/g from the quadratic model, with a regression coefficient of 0.969. This model also showed highly significant effects from changing frequency and time, and less significant effects from changing temperature. The extract from the optimized process showed 89.5% of higher DPPH radical scavenging activity than 71.3% from the conventional process. It was also found that the antioxidant activity of the extract was higher than that of using 13 µg/mL of C3G alone, possibly due to the synergistic effects of C3G with the other bioactive substances in the extract. Therefore, this optimized nonthermal process will be applied to obtain fairly high amounts of a thermally unstable and expensive C3G with fewer purification steps.

Coffee induces breast cancer resistance protein expression in Caco-2 cells

Coffee is a beverage that is consumed world-wide on a daily basis and is known to induce a series of metabolic and pharmacological effects, especially in the digestive tract. However, little is known concerning the effects of coffee on transporters in the gastrointestinal tract. To elucidate the effect of coffee on intestinal transporters, we investigated its effect on expression of the breast cancer resistance protein (BCRP/ABCG2) in a human colorectal cancer cell line, Caco-2. Coffee induced BCRP gene expression in Caco-2 cells in a coffee-dose dependent manner. Coffee treatment of Caco-2 cells also increased the level of BCRP protein, which corresponded to induction of gene expression, and also increased cellular efflux activity, as judged by Hoechst33342 accumulation. None of the major constituents of coffee tested could induce BCRP gene expression. The constituent of coffee that mediated this induction was extractable with ethyl acetate and was produced during the roasting process. Dehydromethylepoxyquinomicin (DHMEQ), an inhibitor of nuclear factor (NF)-κB, inhibited coffee-mediated induction of BCRP gene expression, suggesting involvement of NF-κB in this induction. Our data suggest that daily consumption of coffee might induce BCRP expression in the gastrointestinal tract and may affect the bioavailability of BCRP substrates.

Prophylactic effects of Lonicera japonica extract on dextran sulphate sodium-induced colitis in a mouse model by the inhibition of the Th1/Th17 response

Inflammatory bowel diseases (IBD) are chronically relapsing inflammatory disorders of the intestine. Although some therapeutic agents, including steroids, are available for the treatment of IBD, these agents have limited use. Therefore, dietary supplements have emerged as possible interventions for IBD. Japanese honeysuckle flower, the flower of Lonicera japonica, is a well-known dietary supplement and has been used to prevent or treat various inflammatory diseases. In the present study, we investigated the effects of L. japonica on experimental murine colitis. Colitis was induced by 5 % dextran sulphate sodium (DSS) in Balb/c mice. The water extract of L. japonica (LJE) at doses of 20, 100 or 500 mg/kg was orally administered to mice twice per day for 7 d. Body weight, colon length and a histological damage score were assessed to determine the effects on colitis. Cytokine profiles were assessed to examine the effects on helper T (Th) cell-related immunological responses. In addition, CD4+CD25+Foxp3+T cells were analysed in vivo and in vitro for investigating the effects on regulatory T (Treg) cells. LJE showed dose-dependent inhibitory effects against colon shortening, weight loss and histological damage. LJE down-regulated IL-1β, TNF-α, interferon-γ, IL-6, IL-12 and IL-17. However, LJE did not show any significant effects on IL-10, IL-23, transforming growth factor-β1 and Treg cell populations. In conclusion, LJE showed protective effects against DSS-induced colitis via the Th1/Th17 pathway and not via Treg cell-related mechanisms.

Sulfation of estradiol in human epidermal keratinocyte

Epidermis is one of the well-known estrogen target tissues. Information regarding estrogen metabolism in epidermis is still very limited compared to that of estrogen action. In the breast cancer tissue, 17β-estradiol (E(2)) is inactivated by sulfation and the expression level of estrogen sulfotransferase (SULT1E1) is inversely correlated with its malignancy. However, there is little datum about inactivation of estradiol in skin. In order to detect and measure E(2) and its metabolites simultaneously, we established an assay method with radio HPLC. A majority of [(3)H] labeled E(2) was converted to E(2) sulfate in normal human epidermal keratinocyte (NHEK) cells. The estimated activity of sulfotransferase toward E(2) at 20 nM was 0.11±0.01 (pmol/min/mg protein). Significant induction of estrogen sulfotransferase activity was observed in calcium-differentiated NHEK cells (0.58±0.07 (pmol/min/mg protein)). The gene expression of SULT1E1 was fifteen-fold higher in differentiated keratinocyte than in proliferating keratinocyte, whereas that of steroid sulfatase was reduced. These results suggest that E(2) inactivation is primarily mediated by SULT1E1 in keratinocyte and E(2) action is likely suppressed in epidermal differentiation.

Megadose vitamin C suppresses sulfoconjugation in human colon carcinoma cell line Caco-2

Intake of high doses of vitamin C has known to modulate sulfoconjugation of drugs in the intestine, but the underlying mechanisms for this effect remain to be elucidated. In the present study, we investigated the effects of vitamin C (l-ascorbic acid (AA)) on sulfation of 1-naphthol using Caco-2 cells, a model of human intestinal cells. We found that high dose of AA inhibited the accumulation of 1-naphthyl sulfate in Caco-2 culture medium within 24h in a dose-dependent manner (IC(50)=42 mM). Dehydroascorbic acid (DA), an oxidized form of AA, showed no inhibition. AA did not inhibit the in vitro sulfotransferase (SULT) activity toward 1-naphthol, whereas it reduced the expression of genes belonging to SULT1A family, SULT1A1 and SULT1A3. DA showed no effect on SULT1A gene expression. Consistent with the reduction in gene expression, AA reduced the cytosolic SULT activity towards 1-naphthol in the AA-treated Caco-2 cells. In addition, cAMP exerted an additive effect on AA-mediated repression of SULT1A gene expression. Our results suggest that megadose AA suppresses sulfoconjugation in the intestine mainly by downregulating the expression of SULT1A genes.