• Journal of Life Science
• /
• v.27 no.11
• /
• pp.1262-1268
• /
• 2017

Lemon myrtle (Backhousia citriodora), a plant in the Myrtaceae family, is native to the semitropical rain-forests of Queensland and is presumably the most commercialized native spice. In Australian thousands of lemon-myrtle trees are under tillage. This study was carried out to investigate the alcohol metabolism, hepatoprotective effects and antidiabetic, tyrosinase inhibitory activity of hot-water (LMW) and 80% ethanol (LME) extracts from lemon-myrtle leaves. The alpha-glucosidase (${\alpha}$-glucosidase) inhibitory activities of the LMW and LME extracts were 7.66% and 40.29% at 1 mg/ml (p<0.05), respectively. The tyrosinase inhibitory activity of the LME extract was about 38.26 % at 1 mg/ml. The effects the LMW and LME extracts had on alcohol-metabolizing activities were determined by measuring the generation of reduced nicotinamide-adenine dinucleotide (NADH) by acetaldehyde dehydrogenase (ALDH) and alcohol dehydrogenase (ADH). The ADH activities of the LMW and LME extracts significantly increased in a dose-dependent manner and were about 154.40% and 192.03% at 1 mg/ml, respectively (p<0.05). The ALDH activities of the LMW and LME extracts also significantly increased in a dose-dependent manner and were about 151.14% and 192.34% at 1 mg/ml, respectively (p<0.05). At $100{\mu}g/ml$, the LMW and LME extracts showed significant protective effects against tacrine-induced cytotoxicity in Hep G2 cells. The results suggested that Backhousia citriodora leaf extracts have the potential to be significant sources for natural health products.

• Journal of Society of Preventive Korean Medicine
• /
• v.13 no.2
• /
• pp.51-64
• /
• 2009

Objective : This research was aimed to investigate the anti-tumor effect, safety, mechanism and metabolizing enzyme of Agrimonia pilosa LEDEB(APL) in female C57B/L mouse. Methods : At first, to evaluate the anti-tumor activity of APL, we divided into four groups, normal, control, APL100(100mg/kg), APL150(150mg/kg). LLC obtained American Type Culture Collection was used. LLC had been inoculated to induce tumor. To measure the anti-tumor effect of APL, we calibrate tumor size and weight. To study for mechanism of anti-tumor in APL, we used western blotting and to know metabolizing enzyme in APL we used to real-time PCR. Results : APL100, APL150 inhibited tumor growth after medicine injected. APL did not only induced caspase-dependent apoptosis in LLC-bearing mouse tumor. In APL100, it were decreased 72% in CYP3A11. In APL150, it were decreased 62%, 75% in CYP3A11 and MRP1a respectively. Conclusion : These results suggests that APL has some anti-tumor effects in female C57B/L mouse tumor. APL should be careful use with other drugs related with CYP3A11 or MRP1a.

• Biomolecules & Therapeutics
• /
• v.18 no.2
• /
• pp.159-165
• /
• 2010

Alpinia katsumadai has been widely used in traditional Chinese and Korean medicine to treat a variety of conditions including emesis and gastric disorders such as gastric pain and distended abdomen. To investigate the antinociceptive potential and mechanism of A. katsumadai, ethanolic extracts of A. katsumadai were assayed on cyclooxygenase-2 and evaluated for analgesic activity based on phenylbenzoquinone (PBQ)-induced writhing and carrageenan-induced hyperalgesia tests. A. katsumadai extracts inhibited the cyclooxygenase-2 enzyme activity in a dose-dependent fashion at an $IC_{50}$ value of 0.044 ${\mu}g$/ml. A. katsumadai extract (30-300 mg/kg, orally (p.o.) administered) significantly inhibited PBQ-induced writhing. This inhibition was judged not to be a false positive because a Rota-rod test revealed no difference in muscular coordination when compared to the controls. With regard to the carrageenan-induced hyperalgesia, A. katsumadai extract (30-300 mg/kg, p.o.) produced a significant, dose-dependent increase in the withdrawal response latencies. Naloxone did not reverse the analgesic effect of A. katsumadai extract in the carrageenan-induced hyperalgesia. Taken together, these results suggest that the antinociceptive activity of A. katsumadai is not related to the opioid receptor. A. katsumadai extract has remarkable, non-opioidreceptor-mediated analgesic effects on PBQ-induced writhing and carrageenan-induced hyperalgesia that occur via cyclooxygenase-2 inhibition.

• The Korean Journal of Physiology
• /
• v.29 no.2
• /
• pp.269-277
• /
• 1995

Membrane vesicles were prepared by differential centrifugation from epithelial cells of porcine trachea. Total activity of microsomal ATPases was measured spectrophotometrically by a coupled enzyme assay. The steady-state activity of the enzyme was $329{\pm}10$ nmol/min mg protein. Thapsigargin, a specific antagonist of intracellular $Ca^{2+}-ATPase$, inhibited about 50% of the activity, leaving $178{\pm}18\;nmol/min .mg$ protein (n=6), indicating that the $Ca^{2+}-ATPase$ is one of the major microsomal ATPases. The microsomes used in this study appeared to be tight-sealed vesicles since they showed saturation in $^{45}Ca^{2+}$ uptake experiments. Inositol 1,4,5-trisphosphate $InsP_{3}, 4\;{\mu}M$, an agonist of $InsP_{3}$-sensitive $Ca^{2+}$ release channel ($InsP_{3}$, receptor), and Ca-ionophore A23187 $(10\;{\mu}M)$ induced $^{45}Ca^{2+}$ releases of 20% and 50% of stored $^{45}Ca^{2+}$, respectively. The addition of $(10\;{\mu}M\;InsP_{3}$ also increased the microsomal ATPase activity from $282{\pm}8$ nmol/min mg protein to $334{\pm}21$ nmol/min . mg protein in the intact vesicles. Similar increase in the activity was observed by making microsomes leaky (uncoupling) using the Ca-ionophore A23187. ;$InsP_{3}-induced$ effects were blocked by either thapsigargin or heparin suggesting that: 1) the $InsP_{3}-induced$ increase in ATPase activity is mediated by microsomal $Ca^{2+}-ATPase$, and 2) dissipation of $Ca^{2+}$ gradient across the microsomal membrane is responsible for the $InsP_{3}-induced$ effect. In order to test the dependence of the $Ca^{2+}-ATPase$ activity on the activity of $InsP_{3}-induced$ the activity of ATPases was monitored in various concentrations of free $Ca^{2+}$ using $EGTA-Ca^{2+}$ buffers. The $Ca^{2+}$-dependent biphasic change is the well-known character of $InsP_{3} receptor but not of microsomal $Ca^{2+}-ATPase$ in non-excitable cells; however, the activity of microsomal ATPase appeared biphasic and a maxim진 activity of $397{\pm}36nmol/min\;.mg$ protein was obtained in the solution containing 100 nM free $Ca^{2+}$. Below or above this concentration, the activity of ATPases was lower. These results strongly support a positive correlation of microsomal $Ca^{2+}-ATPase$ to the $InsP_{3}$ receptors in epithelial microsomes.

• Molecules and Cells
• /
• v.46 no.9
• /
• pp.545-557
• /
• 2023

Sphingomyelinase (SMase) catalyzes ceramide production from sphingomyelin. Ceramides are critical in cellular responses such as apoptosis. They enhance mitochondrial outer membrane permeabilization (MOMP) through self-assembly in the mitochondrial outer membrane to form channels that release cytochrome c from intermembrane space (IMS) into the cytosol, triggering caspase-9 activation. However, the SMase involved in MOMP is yet to be identified. Here, we identified a mitochondrial Mg²⁺-independent SMase (mt-iSMase) from rat brain, which was purified 6,130-fold using a Percoll gradient, pulled down with biotinylated sphingomyelin, and subjected to Mono Q anion exchange. A single peak of mt-iSMase activity was eluted at a molecular mass of approximately 65 kDa using Superose 6 gel filtration. The purified enzyme showed optimal activity at pH of 6.5 and was inhibited by dithiothreitol and Mg²⁺, Mn²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Fe²⁺, and Fe³⁺ ions. It was also inhibited by GW4869, which is a non-competitive inhibitor of Mg²⁺-dependent neutral SMase 2 (encoded by SMPD3), that protects against cytochrome c release-mediated cell death. Subfractionation experiments showed that mt-iSMase localizes in the IMS of the mitochondria, implying that mt-iSMase may play a critical role in generating ceramides for MOMP, cytochrome c release, and apoptosis. These data suggest that the purified enzyme in this study is a novel SMase.

• Journal of Chest Surgery
• /
• v.21 no.5
• /
• pp.803-815
• /
• 1988

The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.9
• /
• pp.1279-1286
• /
• 2013

Particle size and metal species are important to both soil microbial toxicity and phytotoxicity in the soil ecosystem. The effects of CuO and ZnO nanoparticles (NPs) and microparticles (MPs) on soil microbial toxicity, phytotoxicity, and bioaccumulation in two crops (Cucumis sativus and Zea mays) were estimated in a soil microcosm. In the microcosm system, soil was artificially contaminated with 1,000 mg/kg CuO and ZnO NPs and MPs. After 15 days, we compared the microbial toxicity and phytotoxicity by particle size. In addition, C. sativus and Z. mays were cultivated in soils treated with CuO NPs and ZnO NPs, after which the treatment effects on bioaccumulation were evaluated. NPs were more toxic than MPs to microbes and plants in the soil ecosystem. We found that the soil enzyme activity and plant biomass were inhibited to the greatest extent by CuO NPs. However, in a Biolog test, substrate utilization patterns were more dependent upon metal type than particle size. Another finding indicated that the metal NP uptake amounts of plants depend on the plant species. In the comparison between C. sativus and Z. mays, the accumulation of Cu and Zn by C. sativus was noticeably higher. These findings show that metal oxide NPs may negatively impact soil bacteria and plants. In addition, the accumulation patterns of NPs depend on the plant species.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.1
• /
• pp.97-102
• /
• 2008

Four hundred and forty 1-day-old Arbor Acre broilers were fed commercial starter diets with 0, 250, 750 and 2,250 mg/kg of an alpha-amylase preparation from 1 to 21 days of age to investigate the effects of an exogenous enzyme on growth performance, activities of digestive enzymes in the pancreas and anterior intestinal contents and pancreatic amylase mRNA expression. Body weight gain (BWG) and average daily gain (ADG) increased linearly (p<0.01) with increasing levels of supplementary amylase but feed conversion ratio (FCR) was not affected. There was a negative quadratic change of protease and amylase in the small intestinal contents with the increase of supplementary amylase level. The activity of intestinal trypsin was also increased (p<0.05). Lipase was unaffected by amylase supplementation (p>0.05). The pancreatic protease, trypsin, and lipase were not affected by exogenous amylase levels. Consistent with the tendency for a linear depression of amylase activity, pancreatic ${\alpha}$-amylase mRNA was down-regulated by dietary amylase supplementation. The present study suggested that oral administration of exogenous amylase affected activities of intestinal enzymes and the production of pancreatic digestive enzymes in a dose-dependent manner.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.1
• /
• pp.57-65
• /
• 2015

β-Glucosidase production by the white rot fungus Flammulina velutipes CFK 3111 was evaluated using different carbon and nitrogen sources under submerged fermentation. Maximal extracellular enzyme production was 1.6 U/ml, corresponding to a culture grown in sucrose 40 g/land asparagine 10 g/l. High production yield was also obtained with glucose 10 g/land asparagine 4 g/l medium (0.5 U/ml). Parameters affecting the enzyme activity were studied using p-nitrophenyl-β-_D-glucopyranoside as the substrate. Optimal activity was found at 50℃ and pHs 5.0 to 6.0. Under these conditions, β-glucosidase retained 25% of its initial activity after 12 h of incubation and exhibited a half-life of 5 h. The addition of MgCl₂, urea, and ethanol enhanced the β-glucosidase activity up to 47%, whereas FeCl₂, CuSO₄, Cd(NO₃)₂, and cetyltrimethylammonium bromide inflicted a strong inhibitory effect. Glucose and cellobiose also showed an inhibitory effect on the β-glucosidase activity in a concentration-dependent manner. The enzyme had an estimated molecular mass of 75 kDa. To the best of our knowledge, F. velutipes CFK 3111 β-glucosidase production is amongst the highest reported to date, in a basidiomycetous fungus.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.7
• /
• pp.998-1003
• /
• 2014

Aspartate aminotransferase (AST; E.C. 2.6.1.1), a vitamin B6-dependent enzyme, preferentially promotes the mutual transformation of aspartate and ${\alpha}$-ketoglutarate to oxaloacetate and glutamate. It plays a key role in amino acid metabolism and has been widely recommended as a biomarker of liver and heart damage. Our study aimed to evaluate the extensive preparation of AST and its application in quality control in clinical laboratories. We describe a scheme to express and purify the 6His-AST fusion protein. An optimized sequence coding AST was synthesized and transformed into Escherichia coli BL21 (DE3) strain for protein expression. Ideally, the fusion protein has a volumetric productivity achieving 900 mg/l cultures. After affinity chromatography, the enzyme activity of purified AST reached 150,000 U/L. Commutability assessment between the engineered AST and standard AST from Roche suggested that the engineered AST was the better candidate for the reference material. Moreover, the AST showed high stability during long-term storage at $-20^{\circ}C$. In conclusion, the highly soluble 6His-tagged AST can become a convenient tool for supplying a much better and cheaper standard or reference material for the clinical laboratory.