Hui-Fen Liao

Optimization of lipase-catalyzed biodiesel by response surface methodology.

Biodiesel prepared by catalyzed mild transesterification has become of much current interest for bioenergy. The ability of a commercial immobilized lipase (Novo Industries--Bagsvaerd, Denmark) from Rhizomucor miehei (Lipozyme IM-77) to catalyze the transesterification of soybean oil and methanol was investigated in this study. Response surface methodology and 5-level-5-factor central composite rotatable design were employed to evaluate the effects on reaction time, temperature, enzyme amount, molar ratio of methanol to soybean oil, and added water content on percentage weight conversion to soybean oil methyl ester by transesterification. Based on ridge max analysis, the optimum synthesis conditions giving 92.2% weight conversion were: reaction time 6.3 h, temperature 36.5 degrees C, enzyme amount 0.9 BAUN (Batch Acidolysis Units NOVO), substrate molar ratio 3.4:1, and added water 5.8%.

Norcantharidin induces anoikis through Jun-n-terminal kinase activation in Ct26 colorectal cancer cells

Norcantharidin (NCTD), a chemically modified form of cantharidin, is a potential anticancer drug. This study investigated the effect of NCTD on anoikis in CT26 colorectal adenocarcinoma cells. NCTD treatment of CT26 cells showed a dose-dependent and time-dependent decrease in viability and cell proliferation. Growth inhibition was accompanied by cell cycle arrest in the S and G2/M phases. Mitogen-activated protein kinase expression, assayed by Western blot, was unchanged except for Jun-N-terminal kinase (JNK). At 24 h of treatment with 0–20 μmol/l NCTD, JNK expression increased at 24 h, but then decreased at 48 h; in contrast, the phosphorylated JNK levels markedly increased. JNK inhibitor (SP600125) in the culture effectively blocked NCTD-induced cytotoxicity and detachment of cells. CT26 cells treated with NCTD not only displayed inhibited cell adhesion and down-expression of integrin &bgr;1, but also changed from being shuttle-shaped to round, the latter cells being more susceptible to anoikis-mediated apoptosis. Flow cytometric assay of the DNA content in NCTD-treated CT26 cells at 24 and 48 h showed a marked increase in the sub-G1 level, indicating that NCTD induced apoptosis. NCTD inhibited the viability of CT26 cancer cells preferentially over normal bone marrow and mononuclear cells. NCTD inhibits CT26 cancer cells by blocking proliferation and inducing anoikis-mediated apoptosis, a process that might be regulated by JNK activation.

Inhibitory effect of norcantharidin, a derivative compound from blister beetles, on tumor invasion and metastasis in CT26 colorectal adenocarcinoma cells

Norcantharidin (NCTD), a potential anti-cancer drug, is the demethylated analog of cantharidin isolated from blister beetles. The present study investigated the effect of NCTD on tumor invasion and metastasis. A cytotoxicity assay of NCTD in CT26 colorectal adenocarcinoma cells showed a dose- and time-dependent decrease in cell viability. NCTD (50 μM)-treated CT26 cells not only showed an inhibited cell invasion of 65.6%, but also decreased the activity of matrix metalloproteinase-2 and -9. NCTD decreased the adhesive ability of CT26 cells in a dose-dependent manner. At a concentration of 100 μM, NCTD showed a down-expression of several cadherin–catenin adhesion molecules, including Desmoglein, N-cadherin, and &agr;- and &bgr;-catenin, while there were no obvious changes in E-cadherin and &ggr;-catenin. Intraperitoneal injection of NCTD (2 mg/kg/day) in BALB/c mice reduced both the pulmonary metastatic capacity of CT26 cells and prolonged the survival day of the mice. These results demonstrated that it was effective in blocking both tumor invasion and metastasis.

Isolation and characterization of an active compound from black soybean [Glycine max (L.) Merr.] and its effect on proliferation and differentiation of human leukemic U937 cells.

Black soybean [Glycine max (L.) Merr.] has been used as a health food and herb in China for hundreds of years. In the present study, we purified a unique polysaccharide component from black soybean (PSBS) and found that it indirectly inhibits proliferation and induces differentiation of human leukemic U937 cells via activation of mononuclear cells (MNCs). We prepared conditioned media (MNC-CM) by incubating MNCs from human peripheral blood with or without PSBS (PSBS-MNC-CM and normal MNC-CM, respectively). Treatment of human leukemic U937 cells with PSBS-MNC-CM significantly inhibited proliferation of U937 cells, reducing their growth by 98.5%. Furthermore, PSBS-MNC-CM induced U937 cells to differentiate into mature monocytes/macrophages (83% by morphological examination and 90% by the nitroblue tetrazolium test). Neither PSBS alone nor normal MNC-CM had such effects. The molecular weight of PSBS was about 480 000 by gel filtration. Structural analysis of PSBS revealed that (1,6)-α-D-glucan might be its major active component. Our results suggest that the PSBS may inhibit proliferation and induce differentiation in human leukemic U937 cells by activating the immune response of MNCs.

Effects of herbal medicinal formulas on suppressing viral replication and modulating immune responses.

The Chinese medicinal herbs Radix Isatidis and Viola yedoensis Makino have been suggested to possess antiviral activity. This study tests whether these and other Chinese and Western herbal medicinal formulas can modulate the immune functions involving virus-suppression in BALB/c mouse. We first confirmed the extract from Viola yedoensis Makino, but not from Radix Isatidis, the traditional Chinese medicine (TCM) formula Chui-Uren-Chien (CUC), or a Western homeopathic medicinal drink Método Canova, could inhibit the replications of herpes simplex virus-1 and enterovirus 71 in the human neuroblastoma SK-N-SH cell line. Subsequently, the same herbal extracts and drink underwent toxicity and immunomodulatory tests on mice of 5-7 weeks old. After 8 weeks of feeding different herbal medicinal formulas, no hepatic or renal toxicity was noted in any tested animal; whereas among the immune function evaluations, only the mice treated with CUC extract were found to be associated with significant increases (p < 0.05) in both the level of plasma IgG and the percentage of monocyte in blood mononuclear cells as well as the activation of macrophage Raw264.7 cells for nitric oxide production, suggesting its role in modulating the non-specific immune response. Analyses using protein arrays showed CUC was the most potent herbal medicinal formula eliciting fluctuations in plasma cytokine and chemokine concentrations. Taking all experimental data together, we conclude Chui-Uren-Chien possesses immunomodulatory capability in mouse, but none of the herbal medicinal formulas tested here are involved in strengthening antiviral immunity.

Application of solvent engineering to optimize lipase-catalyzed 1,3-diglyacylcerols by mixture response surface methodology

Abstract1,3-Diacylglycerol has been introduced in Japan as a cooking oil under the trade name of Econa to reduce body fat accumulation. Solvent engineering was applied to determine the optimum solvent mixtures for the lipase-catalyzed synthesis of 1,3-DAG by mixture response surface methodology. n-Hexane was required to maintain the lipase activity and the product selectivity could be adjusted by changing the hydrophobicity of reaction medium. The optimum yield (∼40%) of 1,3-DAG synthesis was obtained with n-hexane/octane (1:1, v/v).

Resveratrol Inhibits Alpha-Melanocyte-Stimulating Hormone Signaling, Viability, and Invasiveness in Melanoma Cells

Melanoma is a malignancy with high potential to invasion and treatment resistance. The α-melanocyte-stimulating hormone (α-MSH) signal transduction involving Wnt/β-catenin, c-Kit, and microphthalmia-associated transcription factor (MITF), a known pathway to produce melanin, has been demonstrated as one of cancer stem cell characteristics. This study was aimed to examine the effect of resveratrol, an abundant ingredient of grape and medicinal plants, on α-MSH signaling, viability, and invasiveness in melanoma cells. By α-MSH treatment, the melanin production in B16 melanoma cells was augmented as a validation for activation of α-MSH signaling. The upregulated expression of α-MSH signaling-related molecules β-catenin, c-Kit, and MITF was suppressed by resveratrol and/or STI571 treatment. Nuclear translocation of MITF, a hallmark of α-MSH signaling activation, was inhibited by combined treatment of resveratrol and STI571. At effective concentration, resveratrol and/or STI571 inhibited cell viability and α-MSH-activated matrix metalloproteinase- (MMP-)9 expression and invasion capacity of B16 melanoma cells. In conclusion, resveratrol enhances STI571 effect on suppressing the α-MSH signaling, viability, and invasiveness in melanoma cells. It implicates that resveratrol may have potential to modulate the cancer stem cell characteristics of melanoma.

Norcantharidin, Derivative of Cantharidin, for Cancer Stem Cells

Cancer stem cells (CSCs) existing in human cancers have been demonstrated to be a major cause of cancer treatment resistance, invasion, metastasis, and relapse. Self-renewal pathways, Wnt/β-catenin, Sonic hedgehog (Shh), and the Notch signaling pathway play critical roles in developing CSCs and lead to angiogenesis, migration, invasion, and metastasis. Multidrug resistance (MDR) is an unfavorable factor causing the failure of treatments against cancer cells. The most important and thoroughly studied mechanism involved in MDR is the active efflux of chemotherapeutic agents through membrane drug transporters. There is growing evidence that Norcantharidin (NCTD), a water-soluble synthetic small molecule derivative of naturally occurring cantharidin from the medicinal insect blister beetle (Mylabris phalerata Pallas), is capable of chemoprevention and tumor inhibition. We summarize investigations into the modulation of self-renewal pathways and MDR in CSCs by NCTD. This review may aid in further investigation of using NCTD to develop more effective strategies for cancer treatment to reduce resistance and recurrence.

Inhibitory Effect of Tetrandrine on Pulmonary Metastases in CT26 Colorectal Adenocarcinoma–Bearing BALB/c Mice

Tumor metastasis is a major cause of mortality in cancer patients. The anti-metastatic effect of tetrandrine, an alkaloid isolated from Stephania tetrandrae S. Moore, was investigated in a pulmonary metastatic model of colorectal cancer-bearing mice. Tetrandrine decreased the viability of murine colorectal adenocarcinoma CT26 cells in a time- and dose-dependent manner. CT26 cells were injected into BALB/c mice via a tail vein to establish pulmonary metastases. After this, the mice were given intraperitoneal injections of tetrandrine (10 mg/kg/day), 5-fluorouracil (5-FU) at the same dose, or vehicle for 5 consecutive days. Mice treated with tetrandrine had 40.3% fewer metastases than vehicle-treated mice, and those treated with 5-FU had 36.9% fewer metastases than controls. Both tetrandrine- and 5-FU-treated mice survived longer than mice in the untreated control group. There was no acute toxicity or obvious changes in body weight in any of the mice. These results suggest that tetrandrine may be a useful anti-metastatic agent.

Hepatoprotective Effect of Cirsium arisanense Kitamura in Tacrine-Treated Hepatoma Hep 3B Cells and C57BL Mice

Cirsium arisanense Kitamura (Compositae) has been used for hundreds of years in Taiwan as a folk medicine for hepatoprotection. However, no scientific research has demonstrated this effect. In the present study, we extracted the phenol-containing aqueous components of C. arisanense roots (CaR) and leaves/stem (CaL), and then assessed their hepatoprotective activities in both human hepatocellular carcinoma Hep 3B cells and C57BL/6 mice strain. High performance liquid chromatography (HPLC) analysis revealed that the components of CaR and CaL differed from those of the positive control silymarin. CaR exhibited a higher phenolic content and antioxidant capacity than CaL. Hep 3B cells treated with silymarin (0-200 microg/ml) demonstrated a concentration-dependent decrease in viability; however, both CaR and CaL did not exhibit any apparent cytotoxicity. Silymarin at 100 microg/ml, as well as CaR and CaL, not only protect Hep 3B cells from tacrine-induced hepatotoxicity but also decrease the expression of hepatitis B surface antigen (HBsAg). Moreover, an animal experiment demonstrated that CaR, CaL, and silymarin have hepatoprotective effects in C57BL/6 mice injected with tacrine, and they significantly decrease the levels of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST). These effects of CaR and silymarin, but not of CaL, may occur via an increase in the hepatic glutathione level and the elimination of the nitric oxide production. In conclusion, the phenol-containing aqueous components from C. arisanense have potential in hepatoprotection.