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Timilsina PM, Pandey GR, Shrestha A, Ojha M, Karki TB. Purification and characterization of a noble thermostable algal starch liquefying alpha-amylase from Aeribacillus pallidus BTPS-2 isolated from geothermal spring of Nepal. ACTA ACUST UNITED AC 2020; 28:e00551. [PMID: 33240796 PMCID: PMC7674295 DOI: 10.1016/j.btre.2020.e00551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/18/2020] [Accepted: 10/29/2020] [Indexed: 11/29/2022]
Abstract
A thermophilic strain, Aeribacillus pallidus BTPS-2 was isolated from Bhurung geothermal spring of Nepal. The 16 s rRNA sequence showed 99.8 % similarity with the type strain Aeribacillus pallidus DSM 3670. The morphological, physiological and biochemical properties were similar to the type strain. Alpha-amylase from A. pallidus BTPS-2 was purified to 19-fold purification by DEAE-Cellulose ion exchange chromatography. The Km value of amylase on starch was 0.51 ± 0.05 mg/mL. The optimum pH and temperature were 7.0 and 70 °C. SDS-PAGE analysis showed a single band at 100 kDa. The half-life of the enzyme at 80 °C was 2.81 h. The enzyme showed an inhibitory effect in the presence of Fe2+, Pb2+, Sn2+ and Hg2+ at 10 mM concentrations. TLC analysis showed that the enzyme is a liquifying alpha-amylase. The enzyme reduced the viscosity of algal biomass suspension up to 74.2 ± 0.17 % which was more efficient than Bacillus amyloliquefaciens alpha-amylase (80.5 ± 0.2 %).
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Affiliation(s)
| | - Gyanu Raj Pandey
- Department of Biotechnology, Kathmandu University, Dhulikhel, 6250, Nepal.,Biotechnological Research and Developmental Center, Bharatpur, Chitwan, 44200, Nepal
| | - Asmita Shrestha
- Department of Biotechnology, Kathmandu University, Dhulikhel, 6250, Nepal.,Biotechnological Research and Developmental Center, Bharatpur, Chitwan, 44200, Nepal
| | - Manish Ojha
- Department of Biotechnology, Kathmandu University, Dhulikhel, 6250, Nepal
| | - Tika Bahadur Karki
- Department of Biotechnology, Kathmandu University, Dhulikhel, 6250, Nepal
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van der Toorn M, Koshibu K, Schlage WK, Majeed S, Pospisil P, Hoeng J, Peitsch MC. Comparison of monoamine oxidase inhibition by cigarettes and modified risk tobacco products. Toxicol Rep 2019; 6:1206-1215. [PMID: 31768332 PMCID: PMC6872813 DOI: 10.1016/j.toxrep.2019.11.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 10/30/2022] Open
Abstract
The adverse effects of cigarette smoking are well documented, and the two main strategies for reducing smoking prevalence are prevention of smoking initiation and promotion of smoking cessation. More recently, a third and complementary avenue, tobacco harm reduction has emerged, which is aimed to reduce the burden of smoking-related diseases. This has been enabled by the development of novel products such as electronic cigarettes (e-cigarettes) and heated tobacco products, designed to deliver nicotine with significantly reduced levels of the toxicants that are emitted by cigarettes. Several potential modified risk tobacco products (pMRTP) have been reported to emit significantly less toxicants than cigarettes and significantly reduce toxicant exposure in smokers who switch completely to such products. These are two prerequisites for pMRTPs to reduce harm and the risk of smoking-related disease. However, concerns remain regarding the addictive nature of these products. Smoking addiction is a complex phenomenon involving multiple pharmacological and non-pharmacological factors. Although the main pharmacological substance associated with smoking addiction is nicotine, accumulating evidence suggests that nicotine mostly acts as a primary reinforcer and that other factors are involved in establishing smoking addiction. Inhibition of monoamine oxidases (MAO)-mammalian flavoenzymes with a central role in neurotransmitter metabolism-has also been suggested to be involved in this process. Therefore, we aimed to comparatively investigate the ability of several types of pMRTPs and cigarette smoke (3R4F) to inhibit MAO activity. The results showed that the heated tobacco product Tobacco Heating System (THS) 2.2 and the MESH 1.1 e-cigarette possessed no MAO inhibitory activity while 3R4F significantly inhibits the levels of MAO activity (3R4F MAO-A and B; > 2 μM nicotine). Snus products have similar inhibition profiles as 3R4F but for larger nicotine concentrations (snus MAO-A; ∼68-fold, snus MAO-B; ∼23-fold higher compared to 3R4F). These observations were confirmed by analytical datasets of potential MAO inhibitors emitted by these products. In conclusion, we have demonstrated that specific pMRTPs, namely THS 2.2 and MESH 1.1, have a significantly lower MAO-inhibitory activity than 3R4F. These findings provide a basis for further investigation of the role of MAO inhibitors in cigarette addiction as well as the implications of the findings for abuse liability of pMRTPs in comparison with cigarettes.
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Key Words
- 3R4F, reference cigarette
- CRP, CORESTA Reference Product
- CS, cigarette smoke
- DMSO, dimethyl sulfoxide
- E-cigarettes
- FID, flame ionization detection
- GC, gas chromatography
- GCW, General Classic White
- GVP, gas–vapor phase
- Harm reduction
- IC50, half maximal inhibitory concentrations
- Ki, Inhibition Constant
- Km, Michaelis constant
- MAO, monoamine oxidases
- MESH, electronic cigarette
- Monoamine oxidase
- PBS, phosphate-buffered saline
- PMI, Philip Morris International
- PREP, potential reduced exposure products
- RT, room temperature
- Snus
- THS, Tobacco Heating System
- TPM, total particulate matter (TPM)
- Tobacco heating system
- cDNA, complementary DNA
- pMRTP, potential modified risk tobacco products
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Affiliation(s)
- Marco van der Toorn
- Department of Systems Toxicology, PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Kyoko Koshibu
- Department of Systems Toxicology, PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Walter K Schlage
- Biology Consultant, Max-Baermann-Str. 21, 51429, Bergisch Gladbach, Germany
| | - Shoaib Majeed
- Department of Systems Toxicology, PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Pavel Pospisil
- Department of Systems Toxicology, PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Julia Hoeng
- Department of Systems Toxicology, PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Manuel C Peitsch
- Department of Systems Toxicology, PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
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Li J, Olaleye OE, Yu X, Jia W, Yang J, Lu C, Liu S, Yu J, Duan X, Wang Y, Dong K, He R, Cheng C, Li C. High degree of pharmacokinetic compatibility exists between the five-herb medicine XueBiJing and antibiotics comedicated in sepsis care. Acta Pharm Sin B 2019; 9:1035-1049. [PMID: 31649852 PMCID: PMC6804443 DOI: 10.1016/j.apsb.2019.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/22/2019] [Accepted: 04/29/2019] [Indexed: 12/15/2022] Open
Abstract
Managing the dysregulated host response to infection remains a major challenge in sepsis care. Chinese treatment guideline recommends adding XueBiJing, a five-herb medicine, to antibiotic-based sepsis care. Although adding XueBiJing further reduced 28-day mortality via modulating the host response, pharmacokinetic herb–drug interaction is a widely recognized issue that needs to be studied. Building on our earlier systematic chemical and human pharmacokinetic investigations of XueBiJing, we evaluated the degree of pharmacokinetic compatibility for XueBiJing/antibiotic combination based on mechanistic evidence of interaction risk. Considering both XueBiJing‒antibiotic and antibiotic‒XueBiJing interaction potential, we integrated informatics-based approach with experimental approach and developed a compound pair-based method for data processing. To reflect clinical reality, we selected for study XueBiJing compounds bioavailable for drug interactions and 45 antibiotics commonly used in sepsis care in China. Based on the data of interacting with drug metabolizing enzymes and transporters, no XueBiJing compound could pair, as perpetrator, with the antibiotics. Although some antibiotics could, due to their inhibition of uridine 5′-diphosphoglucuronosyltransferase 2B15, organic anion transporters 1/2 and/or organic anion-transporting polypeptide 1B3, pair with senkyunolide I, tanshinol and salvianolic acid B, the potential interactions (resulting in increased exposure) are likely desirable due to these XueBiJing compounds' low baseline exposure levels. Inhibition of aldehyde dehydrogenase by 7 antibiotics probably results in undesirable reduction of exposure to protocatechuic acid from XueBiJing. Collectively, XueBiJing/antibiotic combination exhibited a high degree of pharmacokinetic compatibility at clinically relevant doses. The methodology developed can be applied to investigate other drug combinations.
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Key Words
- 4-MU, 4-methylumbelliferone
- 4-MUG, 4-methylumbelliferyl-β-d-glucuronide
- ABC transporter, ATP-binding cassette transporter
- ADR, adverse drug reaction
- ALDH, aldehyde dehydrogenase
- AMP, adenosine monophosphate
- AQ, amodiaquine
- ATP, adenosine triphosphate
- Antibiotic
- BCRP, breast cancer resistance protein
- BSEP, bile salt export pump
- CLR, renal clearance
- CLtot,p, total plasma clearance
- COMT, catechol-O-methyltransferase
- Cmax, maximum plasma concentration
- Combination drug therapy
- DDI, drug‒drug interaction
- DEAQ, desethylamodiaquine
- E2, β-estradiol
- E217βG, estradiol-17β-d-glucuronide
- E23βG, β-estradiol-3-β-d-glucuronide
- GF, glomerular filtration
- GFR, glomerular filtration rate
- HEK-293, human embryonic kidney 293 cell line
- Herb‒drug interaction
- IC50, half-maximal inhibitory concentration
- Km, Michaelis constant
- MATE, multidrug and toxin extrusion protein
- MDR1, multidrug resistance transporter 1
- MRP, multidrug resistance protein
- NAD+, nicotinamide adenine dinucleotide
- OAT, organic anion transporter
- OATP, organic anion-transporting polypeptide
- OCT, organic cation transporter
- PAH, para-aminohippuric acid
- PK, pharmacokinetic
- PKC, pharmacokinetic compatibility
- Pharmacokinetic compatibility
- SLC transporter, solute carrier transporter
- Sepsis
- TEA, tetraethylammonium
- TFP, trifluoperazine
- TFPG, trifluoperazine-N-β-d-glucuronide
- TS, tubular secretion
- UGT, uridine 5′-diphosphoglucuronosyltransferases
- VSS, apparent volume of distribution at steady state
- XueBiJing
- fe-U, fraction of dose excreted unchanged into urine
- fu-p, unbound fraction in plasma
- t1/2, elimination half-life
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Abstract
Nitric oxide (•NO) is a biologically important short-lived free radical signaling molecule. Both the enzymatic synthesis and the predominant forms of cellular metabolism of •NO are oxygen-dependent. For these reasons, changes in local oxygen concentrations can have a profound influence on steady-state •NO concentrations. Many proteins are regulated by •NO in a concentration-dependent manner, but their responses are elicited at different thresholds. Using soluble guanylyl cyclase (sGC) and p53 as model •NO-sensitive proteins, we demonstrate that their concentration-dependent responses to •NO are a function of the O2 concentration. p53 requires relatively high steady-state •NO concentrations (>600 nM) to induce its phosphorylation (P-ser-15), whereas sGC responds to low •NO concentrations (<100 nM). At a constant rate of •NO production (liberation from •NO-donors), decreasing the O2 concentration (1%) lowers the rate of •NO metabolism. This raises steady-state •NO concentrations and allows p53 activation at lower doses of the •NO donor. Enzymatic •NO production, however, requires O2 as a substrate such that decreasing the O2 concentration below the K m for O2 for nitric oxide synthase (NOS) will decrease the production of •NO. We demonstrate that the amount of •NO produced by RAW 264.7 macrophages is a function of the O2 concentration. Differences in rates of •NO production and •NO metabolism result in differential sGC activation that is not linear with respect to O2. There is an optimal O2 concentration (≈5-8%) where a balance between the synthesis and metabolism of •NO is established such that both the •NO concentration and sGC activation are maximal.
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Key Words
- Autooxidation
- BH4, tetrahydrobiopterin
- DETA/NO, (Z)-1-[N-(2-aminoethyl)–N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate
- FAD, flavin adenine dinucleotide
- FMN, flavin mononucleotide
- Km, Michaelis constant
- LPS, lipopolysaccharide
- NADPH, nicotinamide adenine dinucleotide phosphate, reduced
- NO2−, nitrite
- NO3−, nitrate
- Nitric oxide
- Nitric oxide synthase
- O2, oxygen
- ODQ, 1H-[1,2,4]Oxadiazolo[4,3–a]quinoxalin-1-one
- Oxygen
- P-Ser-15, phospho-serine 15
- Sper/NO, (Z)-1-[N-[3–aminopropyl]–N-[4-(3-aminopropylammonio)butyl]-amino]diazen-1-ium-1,2-diolate
- cGMP, cyclic guanosine monophosphate
- eNOS, endothelial nitric oxide synthase
- iNOS, inducible nitric oxide synthase
- nNOS, neuronal nitric oxide synthase
- p53
- sGC
- sGC, soluble guanylyl cyclase
- •NO, nitric oxide
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Affiliation(s)
- Jason R Hickok
- Departments of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60612-7231, United States
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