• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1221-1229
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• 2019

Mycobacterium tuberculosis, a causative pathogen of tuberculosis (TB), still threatens human health worldwide. To find a novel drug to eradicate this pathogen, we tested taurine-5-bromosalicylaldehyde Schiff base (TBSSB) as an innovative anti-mycobacterial drug using Mycobacterium smegmatis as a surrogate model for M. tuberculosis. We investigated the antimicrobial activity of TBSSB against M. smegmatis by plotting growth curves, examined the effect of TBSSB on biofilm formation, observed morphological changes by scanning electron microscopy and transmission electron microscopy, and detected differentially expressed proteins using two-dimensional gel electrophoresis coupled with mass spectrometry. TBSSB inhibited mycobacterial growth and biofilm formation, altered cell ultrastructure and intracellular content, and inhibited cell division. Furthermore, M. smegmatis adapted itself to TBSSB inhibition by regulating the metabolic pathways and enzymatic activities of the identified proteins. NDMA-dependent methanol dehydrogenase, NAD(P)H nitroreductase, and amidohydrolase AmiB1 appear to be pivotal factors to regulate the M. smegmatis survival under TBSSB. Our dataset reinforced the idea that Schiff base-taurine compounds have the potential to be developed as novel anti-mycobacterial drugs.

• Analytical Science and Technology
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• v.23 no.6
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• pp.531-536
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• 2010

A quantitative analytical method has been established for the measurement of inosine 5'-monophosphate dehydrogenase (IMPDH) activity in human peripheral blood mononuclear cells (PBMCs) by ion-pair reversed-phase high performance liquid chromatography equipped with ultraviolet detection (HPLC/UV). IMPDH is a ${\beta}$-nicotinamide adenine dinucleotide hydrate (NAD+)-dependent dehydrogenase in which the enzyme converts inosine 5'-monophosphate (IMP) into xanthosine 5'-monophosphate (XMP). Its activity was measured by quantifying a HPLC chromatogram corresponding to XMP produced during the incubation of lysed PBMCs with IMP as a substrate and $NAD^+$ as a coenzyme. XMP produced was detected at a wavelength of 260 nm. The mobile phase was composed of a mixture of 37 mM potassium dihydrogen phosphate containing 7 mM tetra-n-butylammonium hydrogen sulfate adjusted to pH 5.5 and methanol (85:15, v/v) with a flow rate of 1 mL/min. The calibration curve was linear ($r^2$=0.999999) in the range of $0.2-50.0\;{\mu}M$ and the limit of quantification (LOQ) was $0.2\;{\mu}M$. The intra- and inter-day precisions were between 0.88-1.47% and 0.85-5.24%, respectively. The intra- and inter-day accuracies were between 98.74-99.99% and 99.95-101.65%, respectively. IMPDH activity in 11 Korean healthy volunteers ranged from 18.29 to 36.60 nmol/h/mg protein (mean = $27.70{\pm}6.28\;nmol/h/mg$ protein).

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.71-77
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• 1985

A bacterium which grows on cyclohexanol as sole carbon and energy source was isolated from sludge of industrial areas in Taegu and identified as Acinetobacter calcoaceticus C-15. The growth medium for the optimal culture condition was composed of 0.2% cyclohexanol, 0.11% $NH_4Cl$, 0.05% $KH_2PO_4$, 0.2% $K_2HPO_4$, 0.02% $MgSO_4{\cdot}7H_2O$, and 0.05% yeast extracts. The optimal pH value and temperature for the growth were 7.2 and $33^{\circ}C$, respectively. Specific growth rate of A. calcoaceticus C-15 at $33^{\circ}C$ on the cyclohexanol and cyclohexanone was $0.27hr^{-1}$ and $0.15hr^{-1}$, respectively. Growth yield for cyclohexanol was 1.0. The bacteria utilized ethanol, 1-butanol, 1-pentanol, and cyclohexanol as a carbon source but not methanol, 1-hexanol, m-cresol, glycerol, and cyclohexane. The bacteria grew on benzoate, adipate, acetate, and citrate, but did not on salicylate, phthalate, p-hydroxybenzoate, and gluconate. A calcoaceticus C-15 did not utilize all kind of sugars other than xylose. Cell-free extracts contained $NAD^+$-linked cyclohexanol dehydrogenase which catalized the oxidation of cyclohexanol to cyclohexanone.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.481-487
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• 2010

The nutritional components, antioxidant, and neuroprotective effects of water and a 50% methanol extract from litchi fruit pericarp were investigated. The most abundant mineral, amino acid, and fatty acid were K, proline, and palmitic acid, respectively. In addition, the total water phenolics and 50% methanol extracts were 8.02 and 12.28 mg/g, respectively. The DPPH, ABTS radical scavenging activities and ferric reducing antioxidant power of the water and 50% methanol extracts showed dose-dependent antioxidant activity. In a cell viability assay using MTT, almost all extracts showed a protective effect against $H_2O_2$-induced neurotoxicity, and lactate dehydrogenase leakage was also inhibited by the pericarp extracts. In particular, the 50% methanol extract showed a higher cell membrane protective effect than the water extract at the highest concentration. Consequently, these data suggest that litchi fruit pericarp can be utilized as an effective and safe functional food substances for natural antioxidants and may reduce the risk of neurodegenerative disorders.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.343-348
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• 2008

In this study, antioxidant activity of methanol extract of Glycyrrhiza uralensis Fisch (GUE) against $H_2O_2$-induced DNA damage in human leucocytcs and cell death in PC12 cells was determined. The effect of GUE on $H_2O_2$-induced DNA damage in human leucocytcs was evaluated by the comet assay, where GUE ($1-50\;{\mu}g/mL$) was a dose dependent inhibitor of DNA damage induced by $H_2O_2$. The protective effect of GUE against $H_2O_2$-induced damage on PC12 cells was investigated by MTT reduction assay and lactate dehydrogenase release assay. A marked reduction in cell survival induced by $H_2O_2$ was significantly prevented by $1-50\;{\mu}g/mL$ of GUE. The enzyme activity of caspase-3 was elevated in $H_2O_2$-treated PC12 cells, while preincubation with GUE for 30 min inhibited $H_2O_2$-induced caspase-3 activation in a dose-dependent manner. In conclusion, GUE ameliorates $H_2O_2$-induced DNA damage in human leucocytes and has neuroprotective effect by preventing cell death in PC12 cell, suggesting that GU may be a potential candidate for novel therapeutic agents for neuronal diseases associated with oxidative stress.

• Nutritional Sciences
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• v.8 no.4
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• pp.212-218
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• 2005

Hepatoprotective effects of the extract of Kochiae fructus (KF), a traditional oriental medicinal plant, were evaluated against carbon tetrachloride($CCl_4$)-induced liver damage in rats. Male Sprague-Dawley rats were divided into control, $CCl_4,\;CCl_4$ plus methanol extract of KF (KFM-$CCl_4$), and $CCl_4$ plus butanol extract of KF (KFB-$CCl_4$) groups. KFM and KFB were orally administered once a day (200 mg/kg body weight) for 14 days. A mixture of 0.2 mL/100 g body weight of $CCl_4$ in olive oil was injected at 30 minutes after the final administration of KFM and KFB. The KFB pretreatment resulted in a significant decrease in the serum transaminase and lactic dehydrogenase levels in the $CCl_4$-treated rats. The $CCl_4$ treatment significantly lowered the activities of glutathione, glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px). However, pretreatment with KFM and KFB resulted in a significant increase in the glutathione, GR and GST levels. KFB increased the activities of SOD, catalase and GSH-Px, but KFM did not alter them. Pretreatment with KFM and KFB resulted in a significant decrease in the production of aminopyrine N-demethylase in the $CCl_4$-treated rats. KF extract would appear to contribute to alleviate the adveISe effect of $CCl_4$ treatment by enhancing the hepatic antioxidant defense system.

• The Journal of Internal Korean Medicine
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• v.27 no.4
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• pp.811-821
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• 2006

Objectives : Diabetes is a disease in which the body does not produce or properly use insulin. Etiological studies of diabetes and its complications showed that oxidative stress might play a major role. Therefore, many methods have been tried to regulate oxygen free radicals for treating diabetes and its complications. Because Mori foliumhas been known to be effective for the treatment of diabetes, the methanol extract of Mori folium was tested for its effectiveness in reducing the oxidative stress induced by streptozotocin. Methods : The crushed Mori folium was extracted 3 times, each time with 3 volumes of methyl alcohol at $60^{\circ}C$ or 24 h. The extract was filtered and evaporated under reduced pressure using a rotary evaporator to yield 11.7 g. Mori folium extract was oral-administered to diabetic rats induced by streptozotocin at 100 mg per 1 kg of body weight for 20 days. The efficacy of the Mori foliumextract was examined with regard to the enzymatic pathways involved in oxygen free radical production and glutathione balance. Results : The effects of the Mori foliumin streptozotocin-induced diabetic rats with regards to body weight, blood glucose and insulin level, hepatic lipid peroxide level, hepatic glutathione level, hepatic glutathione S-transferase and glutathione peroxidase level, hepatic aldose reductase activity, and hepatic sorbitol dehydrogenase activity were shown to be good enough to cure and prevent diabetes and its complications. Conclusions : These results indicated that Mori folium might reduce oxidative stress in tissues and organs by regulating the production of oxygen free radicals. Especially Mori folium might prevent and cure diabetes and its complications by reducing oxidative stress in the ${\beta}-cells$ of the pancreas.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.1035-1040
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• 2007

Epidemiologic studies have shown important relationships between oxidative stress and Alzheimer's disease (AD) brain. In this study, free radical scavenging activity and neuronal cell protection effect of aqueous methanol extracts of Acanthopanax senticosus (A. senticosus) were examined. $H_2O_2$-induced oxidative stress was measured using 2',7'-dichlorofluorescein diacetate (DCF-DA) assay. Pretreatment with the phenolics of A. senticosus prevented oxidative injury against $H_2O_2$ toxicity. Since oxidative stress is known to increase neuronal cell membrane breakdown, leading to cell death, lactic dehydrogenase release, and trypan blue exclusion assays were utilized. We found that phenolics of A. senticosus have neuronal cell protection effects. It suggests that the phenolics of A. senticosus inhibited $H_2O_2$-induced oxidative stress and A. senticosus may be beneficial against the oxidative stress-induced risk in AD.

• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.965-972
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• 2015

This study was conducted to evaluate the neuroprotective effects of Cheonggukjang extract in in-vitro and in-vivo models. T98G-human glioblastoma cells were pretreated with various concentrations (1~10 mg/mL) of Cheonggukjang extract for 24 h and then exposed to $H_2O_2$ (1 mM) for 3 h. The neuroprotective effects of Cheonggukjang extract were measured using a CCK-8 kit assay, total antioxidant capacity (TAC) assay, reactive oxygen species (ROS) assay, and lactate dehydrogenase (LDH) release assay. The early stage focal ischemia rodent model was used as the in-vivo neurotoxicity model. Various concentrations (10~200 mg) of Cheonggukjang extract were administered to the animal models for 1 week. Peripheral blood was analyzed for glutathione peroxidase (GPx) expression by ELISA, and infarct volume reduction was analyzed by TTC staining. Cheonggukjang extract significantly (p<0.05) increased cell viability in T98G cells against $H_2O_2$ as well as against the induced neurotoxicity. Indeed, treatment with the Cheonggukjang extract induced a decrease in ROS and LDH expression and increased TAC significantly (p<0.05). However, Cheonggukjang extract did not induce a decrease in infarct volume or an increase in GPx expression in the in-vivo model. Despite the limitation in neuroprotection, Cheonggukjang extract may be useful for treating ROS injury.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.261-267
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• 2005

Alcohol metabolizing and antioxidant activity of Mentha species were investigated in rat liver. Fifty six Sprague Dawley rats were randomly divided into seven groups such as normal (ethanol excluded), negative control (40% ethanol (10 g/kg of body weight/day) fed), positive control (1 g Silymarin/kg of body weight/day with ethanol fed), two Mentha viridis extracts (0.2 g & 1 g M. viridis methanol ext./kg of body weight/day with ethanol fed) and two M piperita extracts (0.2 g & 1 g M. piperita methanol ext./kg of body weight/day with ethanol fed) groups. After 2 weeks, rats were sacrificed under ether. The activities of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), catalase (CAT), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase (GAH-px) and the content ofthiobarbituric acid reactive substance (TBARS) in the rat livers and the activity of glutamate pyruvate transferase (GPT) in serum were evaluated. From the analyses, 1 g M. viridis and 0.2 g M. piperita administrated groups showed higher ADH and ALDH activity than the other groups. Groups fed with 0.2 g and 1 g M. viridis ext. and 0.2 g M. piperita ext. showed higher CAT activity than the other groups. All the Mentha extract fed groups exhibited more effective in recovering Mn-SOD, GSH-px and GPT acitivities to a similar degree of normal group. TBARS contents of two M. viridis ext. fed group and 0.2 g M. piperita ext. fed group were higher than those of the other groups. M. viridis extract fed groups showed more effective in CAT and Mn-SOD activities than M. piperita extract groups at p < 0.05. Finally, it is concluded that both Mentha species have alcohol metabolizing and antioxidant activity and M viridis is more effective than M. piperita.