Sup Kim

Antioxidant activities of selected oriental herb extracts

Antioxidant activities of methanol extracts of 180 Oriental herbs were studied by determining the peroxide values of linoleic acid during storage at 50°C. Among the herb extracts tested, 44 species showed strong antioxidant activities on the oxidation of linoleic acid. The antioxidative effects of these 44 selected herb extracts were studied further in a methyl linoleate system during storage for 35 d. Among the 44 species tested, 11 species had particularly high antioxidative effects. The effects of type of extraction solvent (methanol, petroleum ether and ethyl acetate) on the antioxidant activities of the 11 species were studied. Antioxidant activities of most herb extracts were greatly dependent on the extraction solvent used; however, some of the extracts showed strong antioxidant activities regardless of the solvents used for the extraction. Among the 11 herbs selected, based on the antioxidant activity of their methanol extracts, two (i.e.,Psoralea corylifolia L. andSorphora angustifolia Sieb. & Zucc.) were selected for further study in lard held at 75°C for 7 d. The methanol extracts ofP. corylifolia L. andS. angustifolia Sieb. & Zucc. greatly decreased the peroxide formation of lard during storage. Treatment with 0.20% methanolic extract ofP. corylifolia L. exhibited significantly stronger antioxidant effect on the oxidation of lard than treatment with 0.02% butylated hydroxyanisole (P<0.05).

Riboflavin-sensitized photooxidation of ascorbic acid: kinetics and amino acid effects

Abstract The study on the effects of riboflavin contents and light intensity on the riboflavin-sensitized decomposition of ascorbic acid indicated that light and riboflavin accelerated the decomposition of ascorbic acid. The relative photosensitizing activity of riboflavin, methylene blue and protoporphyrin IX was 21:15:1 at 1–2 ppm. The rate constants for reaction of ascorbic acid with singlet oxygen at pH 7·5, 6·0 and 4·5 were 6·63 × 10 8 , 5·77 × 10 8 and 5·27 × 10 8 M −1 s −1 , respectively. Cysteine showed strong antioxidant activity on both riboflavin- and methylene blue-sensitized photooxidation of ascorbic acid and its antioxidant effect was concentration-dependent. Alanine and phenylalanine at 0·1% concentration showed antioxidant effects on the riboflavin-sensitized photooxidation of ascorbic acid but prooxidant effects on the methylene blue-sensitized photooxidation. Tyrosine (0·1%) exhibited strong prooxidant activity on both the riboflavin- and methylene blue-sensitized photooxidation of ascorbic acid. However, tryptophan (0·1%,) showed antioxidant or prooxidant activity on the photooxidation of ascorbic acid depending on the storage time.

Destruction of Bacillus licheniformis spores by microwave irradiation

Aims:u2002 To investigate the sporicidal mechanisms of microwave irradiation on Bacillus licheniformis spores.

Taste and flavor compounds in box thorn (Lycium chinense Miller) leaves

Abstract Contents of selected taste components in box thorn leaves collected at different seasons (from mid-May to mid-October) were determined. Volatile flavor compounds in the box thorn leaves were extracted using a simultaneous steam distillation-extraction apparatus, and the compounds were isolated and identified by gas chromatography/mass spectrometry. Box thorn leaves contained fructose (0.58–1.54%), glucose (0.33–1.33%), sucrose (0.23–0.68%) and maltose (0.60–0.98%). Non-volatile organic acids identified were citric acid (162.3–361.3 mg%), oxalic acid (61.1–130.9 mg%), malonic acid (44.9–59.4 mg%), malic acid (15.6–34.3 mg%), succinic acid (3.7–5.1 mg%), fumaric acid (1.3–2.9 mg%), and lactic acid (0.0–1.1 mg%). Eighteen free amino acids were found in the leaves and their contents varied greatly with season. Proline (52.6–267 mg%), histidine (162–244 mg%) alanine (99.5–198 mg%), leucine (51.4–149 mg%), valine (54.5–125 mg%), isoleucine (37.0–119 mg%) and aspartic acid (46.7–111 mg%) were major amino acids in the leaves. Total tannin contents were 0.90–2.10%, showing the highest amount in October. Forty-five volatile flavor components were identified in the leaves for the first time. These included four acids, 15 alcohols, seven aldehydes, two esters, three furans, nine hydrocarbons, two ionones, and three other compounds.

The effects of high-power microwaves on the ultrastructure of Bacillus subtilis.

Aims:u2002 To investigate the microbicidal mechanisms of high‐power microwave (2·0u2003kW) irradiation on Bacillus subtilis and to determine the effect of this procedure on the ultrastructure of the cell wall.

Photodecomposition of aspartame in aqueous solutions

Photodecomposition of aspartame in aqueous solutions under different conditions of light intensity and pH were studied. The effects of photosensitizers (riboflavin and methylene blue) and ascorbic acid on aspartame stability in aqueous solutions at different pH under light were also studied. Light illumination significantly increased aspartame degradation in an aqueous solution (pH 7), indicating that aspartame was very unstable under the illuminated conditions. In the dark, 91% of aspartame in an aqueous solution at pH 7 remained after 10 h of storage. Under 5500 1x of light, however, 39% of aspartame in the solution was destroyed after 10 h of storage. Aspartame degradation under light followed simple zero-order reaction kinetics. The higher the light intensity, the greater the degradation of aspartame. The relative reaction rate for the destruction of aspartame under 0, 1100, 3300 and 5500 1x was 1:1.42:2.80:4.61. The photodecomposition rate of aspartame varied with the pH of the system. Aspartame degradation was fastest at pH 7.0, followed by pH 4.0 and pH 6.0, in decreasing order. Addition of 4.8 ppm riboflavin or 4.8 ppm methylene blue significantly accelerated the aspartame decomposition at pH 7 in the presence of light. There were, however, no significant photosensitizing effects of these sensitizers on aspartame destruction at pH 6 and pH 4. Addition of 1.2 × 10−4 M ascorbic acid greatly increased the aspartame degradation at pH 7.0, but did not affect the destruction rate of aspartame at pH 6.0 and pH 4.0.

Retrospective analysis of treatment outcomes after postoperative chemoradiotherapy in advanced gastric cancer

Purpose To evaluate retrospectively the survival outcome, patterns of failure, and complications in patients treated with postoperative chemoradiotherapy (CRT) in advanced gastric cancer. Materials and Methods Between January 2000 and December 2006, 80 patients with advanced gastric cancer who received postoperative concurrent CRT were included. Pathological staging was IB-II in 9%, IIIA in 38%, IIIB in 33%, and IV in 21%. Radiotherapy consisted of 45 Gy of radiation. Concurrent chemotherapy consisted of a continuous intravenous infusion of 5-fluorouracil and leucovorin on the first 4 days and last 3 days of radiotherapy. Results The median follow-up period was 48 months (range, 3 to 83 months). The 5-year overall survival, disease-free survival, and locoregional recurrence-free survivals were 62%, 59%, and 80%, respectively. In the multivariate analysis, significant factors for disease-free survival were T stage (hazard ratio [HR], 0.278; p = 0.038), lymph node dissection extent (HR, 0.201; p = 0.002), and maintenance oral chemotherapy (HR, 2.964; p = 0.004). Locoregional recurrence and distant metastasis occurred in 5 (6%) and 18 (23%) patients, respectively. Mixed failure occurred in 10 (16%) patients. Grade 3 leukopenia and thrombocytopenia were observed in 4 (5%) and one (1%) patient, respectively. Grade 3 nausea and vomiting developed in 8 (10%) patients. Intestinal obstruction developed in one (1%). Conclusion The survival outcome of the postoperative CRT in advanced gastric cancer was similar to those reported previously. Our postoperative CRT regimen seems to be a safe and effective method, reducing locoregional failure without severe treatment toxicity in advanced gastric cancer patients.

Methanolic extract of Coptis japonica Makino reduces photosensitized oxidation of oils

Antioxidative activities of methanolic extracts of 47 plants on the methylene blue-sensitized or chlorophyll-sensitized photooxidations of linoleic acid were studied to select the plant species which possess the strong antioxidative activity in sensitized photooxidation of oil. The methanol extract of Coptis japonica Makino showed the strongest antioxidative activity in both methylene blue-sensitized and chlorophyll-sensitized photooxidations of linoleic acid. The study on the extracting solvent effects indicated that the antiphotooxidative components in the Coptis japonica Makino possess strong polar property, and are easily extracted with highly polar solvent (methanol). The methanol extract of Coptis japonica Makino was fractionated into three fractions (ethyl ether fraction, ethyl acetate fraction and butanol fraction) by liquid–liquid partitioning fractionation. Among the tested fractions, the butanol fraction showed strongest antioxidative activity in both chlorophyll-sensitized and methylene blue-sensitized photooxidation of linoleic acid. The butanol fraction also significantly inhibited the photooxidation of model food emulsion (50% soybean oil emulsion). The treatment with 0.3% (w/w) butanol fraction resulted in 64.9% inhibition of photooxidation of the model food emulsion during 60 h fluorescent light illumination.

PPAR-α Activation Mediates Innate Host Defense through Induction of TFEB and Lipid Catabolism

The role of peroxisome proliferator–activated receptor α (PPAR-α) in innate host defense is largely unknown. In this study, we show that PPAR-α is essential for antimycobacterial responses via activation of transcription factor EB (TFEB) transcription and inhibition of lipid body formation. PPAR-α deficiency resulted in an increased bacterial load and exaggerated inflammatory responses during mycobacterial infection. PPAR-α agonists promoted autophagy, lysosomal biogenesis, phagosomal maturation, and antimicrobial defense against Mycobacterium tuberculosis or M. bovis bacillus Calmette–Guérin. PPAR-α agonists regulated multiple genes involved in autophagy and lysosomal biogenesis, including Lamp2, Rab7, and Tfeb in bone marrow–derived macrophages. Silencing of TFEB reduced phagosomal maturation and antimicrobial responses, but increased macrophage inflammatory responses during mycobacterial infection. Moreover, PPAR-α activation promoted lipid catabolism and fatty acid β-oxidation in macrophages during mycobacterial infection. Taken together, our data indicate that PPAR-α mediates antimicrobial responses to mycobacterial infection by inducing TFEB and lipid catabolism.

Prognostic significance of human apurinic/apyrimidinic endonuclease (APE/Ref-1) expression in rectal cancer treated with preoperative radiochemotherapy.

PURPOSEnHuman apurinic endonuclease/redox factor 1 (APE/Ref-1) mediates repair of radiation-induced DNA lesions and regulates transcription via redox-based activation. We investigated the predictive and prognostic significance of APE/Ref-1 expression in pretreatment biopsy specimens in locally advanced rectal cancer (LARC) (cT3-T4 or N+).nnnMETHODS AND MATERIALSnAPE/Ref-1 expression was analyzed by immunohistochemistry in pretreatment biopsy specimens obtained from 83 patients with LARC. Patients received preoperative radiotherapy of 50.4 Gy in 28 fractions, combined with oral capecitabine and leucovorin chemotherapy, followed by curative surgery. The prognostic significance of various clinicopathologic characteristics, including APE/Ref-1 protein expression, was evaluated.nnnRESULTSnAPE/Ref-1 was expressed in 97% of patient samples. Exclusive APE/Ref-1 nuclear staining was observed in 49 of 83 samples (59%), and mixed nuclear and cytoplasmic staining was observed in 31 samples (37%). APE/Ref-1 nuclear expression levels were low in 49 patients (59%) and high in 34 patients (41%). The level of APE/Ref-1 nuclear expression was not a prognostic factor for overall and disease-free survival. Cytoplasmic expression of APE/Ref-1 was a borderline-significant predictive factor for pathologic tumor response (p = 0.08) and a significant prognostic factor for disease-free survival, as shown by univariate analysis (p = 0.037). Multivariate analysis confirmed that cytoplasmic localization of APE/Ref-1 is a significant predictor of disease-free survival (hazard ratio, 0.45; p = 0.046).nnnCONCLUSIONSnAPE/Ref-1 was expressed in a majority of pretreatment biopsy specimens from patients with LARC. The level of APE/Ref-1 nuclear expression was not a significant predictive and prognostic factor; however, cytoplasmic localization of the protein was negatively associated with disease-free survival. These results indicate that cytoplasmic expression of APE/Ref-1 represents an adverse prognostic factor for LARC patients who receive preoperative radiochemotherapy.