• The Korean Journal of Physiology and Pharmacology
• /
• v.13 no.3
• /
• pp.229-239
• /
• 2009

The aim of the present study was to examine the effect of provinol, which is a mixture of polyphenolic compounds from red wine, on the secretion of catecholamines (CA) from isolated perfused rat adrenal medulla, and to elucidate its mechanism of action. Provinol (0.3 ${\sim}$ 3 ${\mu}g/ml$) perfused into an adrenal vein for 90 min dose- and time-dependently inhibited the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_N$ receptor agonist, 100 ${\mu}M$) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100 ${\mu}M$). Provinol itself did not affect basal CA secretion. Also, in the presence of provinol (1 ${\mu}g/ml$), the secretory responses of CA evoked by Bay-K-8644 (a voltage-dependent L-type dihydropyridine $Ca^{2+}$ channel activator, 10 ${\mu}M$), cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10 ${\mu}M$) and veratridine (an activator of voltage-dependent $Na^+$ channels, 10 ${\mu}M$) were significantly reduced. Interestingly, in the simultaneous presence of provinol (1 ${\mu}g/ml$) plus L-NAME (a selective inhibitor of NO synthase, 30 ${\mu}M$), the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclpiazonic acid recovered to the considerable extent of the corresponding control secretion in comparison with the inhibition of provinol-treatment alone. Under the same condition, the level of NO released from adrenal medulla after the treatment of provinol (3 ${\mu}g/ml$) was greatly elevated in comparison to its basal release. Taken together, these data demonstrate that provinol inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the perfused rat adrenal medulla. This inhibitory effect of provinol seems to be exerted by inhibiting the influx of both calcium and sodium into the rat adrenal medullary cells along with the blockade of $Ca^{2+}$ release from the cytoplasmic calcium store at least partly through the increased NO production due to the activation of nitric oxide synthase.

• Nutrition Research and Practice
• /
• v.9 no.2
• /
• pp.137-143
• /
• 2015

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-${\alpha}$, related to ${\beta}$-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing ${\beta}$-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake ($0.4{\times}10^{-5}$ vs $0.4{\times}10^{-5}$ mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.

• Current Research on Agriculture and Life Sciences
• /
• v.9
• /
• pp.51-59
• /
• 1991

This study was conducted to understand browning characteristics of Chinese Chestnut during processing and storage. For this, the isolation and identification of polyphenolic compounds and the biochemical characteristics of polyphenol oxidase(PPO) were investigated. The content of total phenol was $6.5{\mu}g/g$ and it was consisted of ferulic acid, caffeic acid, synapic acid, p-coumaric acid, gallic acid and salicylic acid in order. PPO was purified 11.7 fold through ammonium sulfate fractionation, DEAE-cellulose column chromatography and Sephadex G-200 column chromatography. Purified enzyme showed single protein and activity band by polyacrylamide gel electrophoresis. The optimum pH and temperature of PPO were 5.9 and $45^{\circ}C$, respectively. The activity of PPO was lost 93% by exposing at $80^{\circ}C$ for 15minutes. $Mg^{{+}{+}}$, $Ca^{{+}{+}}$, $Zn^{{+}{+}}$ increased the activity of PPO, but $Fe^{{+}{+}}$, $K^+$, $Hg^{{+}{+}}$ inhibited PPO at 10mM concentration. L-ascorbic acid, thiourea, sodium chloride and L-cysteine were effective inhibitors of PPO. The activity of PPO was higher for o-diphenols than other polyphenols. The Km value of PPO for catechol was 5mM.

• The Korean Journal of Physiology and Pharmacology
• /
• v.13 no.6
• /
• pp.517-526
• /
• 2009

The present study was attempted to investigate whether polyphenolic compounds isolated from wine, which is brewed from Rubus coreanum Miquel (PCRC), may affect the release of catecholamines (CA) from the isolated perfused adrenal medulla of the spontaneously hypertensive rats (SHRs), and to establish its mechanism of action. PCRC $(20\sim180\;{\mu}g/ml)$ perfused into an adrenal vein for 90 min relatively dose-dependently inhibited the CA secretory responses to ACh (5.32 mM), high $K^+$ (56 mM), DMPP $(100\;{\mu}M)$ and McN-A-343 $(100\;{\mu}M)$. PCRC itself did not affect basal CA secretion (data not shown). Also, in the presence of PCRC $(60\;{\mu}g/ml)$, the CA secretory responses to veratridine (a selective $Na^+$ channel activator $(10\;{\mu}M)$, Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, $10\;{\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, $10\;{\mu}M$) were significantly reduced, respectively. In the simultaneous presence of PCRC $(60\;{\mu}g/ml)$ and L-NAME (an inhibitor of NO synthase, $30\;{\mu}M$), the inhibitory responses of PCRC on the CA secretion evoked by ACh, high $K^+$, DMPP, and Bay-K-8644 were considerably recovered to the extent of the corresponding control secretion compared with that of PCRC-treatment alone. The level of NO released from adrenal medulla after the treatment of PCRC $(60\;{\mu}g/ml)$ was greatly elevated compared with the corresponding basal level. Taken together, these results demonstrate that PCRC inhibits the CA secretion from the isolated perfused adrenal medulla of the SHRs evoked by stimulation of cholinergic receptors as well as by direct membrane-depolarization. It seems that this inhibitory effect of PCRC is mediated by blocking the influx of calcium and sodium into the adrenal medullary chromaffin cells of the SHRs as well as by inhibition of $Ca^{2+}$ release from the cytoplasmic calcium store at least partly through the increased NO production due to the activation of NO synthase.

• Korean Chemical Engineering Research
• /
• v.54 no.3
• /
• pp.310-314
• /
• 2016

The search for natural antioxidants as alternatives to synthetic products is growing. Microalgae have emerged as a source of natural antioxidants with significant and diverse health-promoting properties. In this study, the effects of hot-water extraction conditions on total polyphenol compounds (TPC) production were investigated for lipid extracted microalgae (LEA). In order to enhance the polyphenol productivity, the extraction variables including solvents, temperature, time and ethanol concentration were optimized. The results showed hot-water extraction provided a higher extraction efficiency than the organic solvents and extraction at high temperatures showed a better extraction efficiency. While hot-water extract showed a higher extraction efficiency compared to 98% ethanol extraction, the mixture of water and ethanol (40:60 v/v) showed the highest production of polyphenols. The maximum polyphenols of 3.35 mg GAE (gallic acid equivalent)/g DM were obtained at the optimized extraction time of 10 min, $100^{\circ}C$ and 40% ethanol, respectively. Although Tetraselmis KCTC 12236BP was preprocessed by hexane to remove lipid for bio-diesel production, the results showed LEA contains relatively high level of polyphenols compared to untreated microalgae which can be used in the production of value-added materials. The predictions obtained from the developed Peleg's model were compared with the experimental data under the same operating conditions. The predicted and experimental data were consistent, indicating the reliability of the model.

• Food Science and Preservation
• /
• v.23 no.3
• /
• pp.445-452
• /
• 2016

In this study, physicochemical properties of acorn flour was investigated, and characteristics of the Jeung-pyun dough added with the acorn flour at various concentrations were evaluated after storage at -$18^{\circ}C$ for 4 weeks and fermentation. Total polyphenolic content, electron donating ability (EDA) of 0.5%, gelatinization onset temperature (To), gelatinization peak temperature (Tp), and gelatinization conclusion temperature (Tc) of acorn flour were 3,525.12 mg%, 16.71%, $68.41^{\circ}C$, $73.83^{\circ}C$, and $82.96^{\circ}C$, respectively. These all values were increased in the Jeung-pyun dough possibly due to addition of the acorn flour. The yeast count was not affected by the addition levels of acorn flour and the frozen storage period before fermentation. The amount of carbon dioxide gas evolved from Jeung-pyun dough during fermentation was significantly changed with the concentration of acorn flour, but it was negligible. The Jeung-pyun added with 6% acorn flour showed an small increase in the amount of carbon dioxide after frozen storage of 1 wk and fermentation. The pH of the fermented Jeung-pyun samples decreased along with the increasing storage period as well as the increasing acorn flour content, ranging from 4.21 to 5.34. Therefore, the frozen Jeung-pyun dough containing 6~15% of acorn flour and stored for 3 weeks was the most desirable among all the tested samples in this study.

• Food Science and Preservation
• /
• v.17 no.1
• /
• pp.100-106
• /
• 2010

The contents and antioxidant activities of various polyphenolic fractions from commercial cocoa powder were investigated. Total phenolics extracted by 0.01 M HCl, ethyl acetate, and acidic methanol, from an 80% (v/v) methanolic extract of cocoa, were 19.25, 202.24, and 295.83 mg/g, respectively. Each fraction was capable of scavenging DPPH radicals in a concentration-dependent manner. Among the various fractions, the acidic methanol fraction had the highest ABTS radical scavenging ability. The reducing power of the 0.01 M HCl, ethyl acetate, and acidic methanol fractions were 0.44, 3.15, and 3.87, respectively, at 1,000 ${\mu}g/mL$. Antioxidant activities, as assessed by $\beta$-carotene bleaching and linoleic acid autoxidation, of the various phenolic fractions from cocoa decreased in the order acidic methanol > ethyl acetate > 0.01 M HCl. Inhibition of $\beta$-carotene bleaching mediated by the acidic methanol fraction was similar to that of the ethyl acetate fraction. The values were 60.18% and 58.97%, respectively, at 1,000 ${\mu}g/mL$. Therefore, cocoa and cocoa-containing products may contain natural antioxidants useful in prevention of diseases associated with aging.

• Food Science and Preservation
• /
• v.16 no.2
• /
• pp.147-154
• /
• 2009

Radish sprout was packaged with different materials. PO and PC are both hard case PET(polyethylenterephthalate) and has 6 holes and no holes, respectively. LO, LM and LH are anti-fogging OPP(oriented polypropylene) film which have different oxygen transmission rates. The oxygen concentration and weight loss rate in PO packaged were higher than any other packages. The soluble solid contents of radish sprouts packaged with PO showed much increased during storage. The pH increased during storage but pH of the samples packaged with high oxygen transmission rate was relatively low. Radish sprouts in LO had lower b value as compared to other samples. The result of ${\Delta}E$ value was generally high during storage period, especially at 7 days storage. The contents of total polyphenolic compounds and free radical scavenging activity of radish sprout packaged with PC and LO were high. Total aerobic bacteria of sprouts in PC and LO was much higher than others. The result of organoleptic qualities showed that the radish sprouts packaged with LM had a good score in terms of overall acceptability until 7 days storage.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.9
• /
• pp.1220-1225
• /
• 2012

Ligularia stenocephala leaves were subjected to extraction by using several solvents with different polarities, which were then investigated for their antioxidant and antimicrobial activities. Extraction yield of ethanol extract of Ligularia stenocephala was 21.36%. The water fraction showed the highest extraction yield of 60.35%, followed by the n-butanol, n-hexane, and ethyl acetate fractions. Total polyphenolic content was the highest (254.00 mg/g GAE) in the ethyl acetate fraction of Ligularia stenocephala extract. The ethyl acetate fraction had $IC_{50}$ values of 0.28 mg/mL for DPPH radical scavenging, and 96.$67{\pm}0.09%$ for ABTS radical scavenging activity. Further, FRAP value was significantly higher in the ethyl acetate fraction. The ethyl acetate fraction showed antimicrobial activities against B. cereus, and the diameter of the zone of inhibition was 10.2 mm at 5 mg/disc. These results suggest that the ethyl acetate fraction of Ligularia stenocephala possesses the antimicrobial activities against B. cereus, and its high antioxidant activity could be applicable to food additives and as a natural cosmetic ingredient.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.10
• /
• pp.1338-1345
• /
• 2012

This study investigated the antioxidant activities, whitening effects, and antimicrobial activities of fractions from Pleurospermum kamtschaticumin extract. Total polyphenolic contents of fractions from Pleurospermum kamtschaticumin extract were 116.44~382.73 mg/g GAE (gallic acid equivalent), with the highest value in the ethyl acetate fraction. Fractions of Pleurospermum kamtschaticumin showed the highest DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity ($IC_{50}$=0.04 mg/mL) and ABTS radical scavenging activity (98.86% at 0.5 mg/mL), which was similar to ascorbic acid. Further, reducing power and FRAP activity were significantly high in the ethyl acetate and n-butanol fractions. The ethyl acetate and n-butanol fractions showed significantly high SOD-like activities (1 mg/mL, 86.93%, and 78.23%, respectively) compared to other fractions. Tyrosinase inhibition activities of the n-butanol fraction and 80% ethanol extract were 43.52% and 41.64%, respectively. Antimicrobial activity against Escherichia coli was only observed in the chloroform fraction (16.7 mm in 0.5 mg/disc). These results suggest that fractions from Pleurospermum kamtschaticumin extract show comparatively high antioxidant activity and thus could be used as a food additive or cosmeceutical ingredient.