• 한국가축번식학회지
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• 제23권1호
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• pp.29-36
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• 1999

본 연구는 Hamster 정소상체 정자의 운동성에 영향을 미치는 methylxanthine derivatives 의 효과를 알아보고자 수행하였다 . Pentoxifylline 을 첨가하였을 때 운동 형태에 대한 첨가효과는 정소상체 체부에서 차이를 보였으며, 농도에 대한 변화는 1 mM 농도군에서 현저한 차이를 나타냈다. 2-Deoxya-denosine 첨가군에서도 pentoxifylline 첨가군과 같이 특히 VCL 이 정소상체 체부 정자부터 증가하였으며 다른 농도군에 비해 1 mM 과 2 mM 에서 차이가 났다. Hypoxanthine 첨가군은 1 mM 농도에서 다른 첨가군에 비해 운동 형태가 증가하였다. 그러나 pentoxifylline 과 adenosine 첨가군과는 달리 농도를 달리하여도 뚜렷한 운동형태의 변화는 관찰되지 않았다. VCL 과 VAP 는 pentoxifylline 1 mM 과 2-Deoxyadenosine 1 mM 첨가군에서 정소상체 체부 정자의 운동성이 증가하고 hypoxanthine 1 mM 첨가군도 유의하게 증가하였다. 결론적으로 hamster 정소상체 정자의 운동성은 적정한 농도의 methylxanthine derivatives 의 첨가로 증가됨을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1147-1155
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• 2018

The degradation efficiency and catabolism pathways of the different methylxanthines (MXs) in isolated caffeine-tolerant strain Pseudomonas putida CT25 were comprehensively studied. The results showed that the degradation efficiency of various MXs varied with the number and position of the methyl groups on the molecule (i.e., xanthine > 7-methylxanthine ${\approx}$ theobromine > caffeine > theophylline > 1-methylxanthine). Multiple MX catabolism pathways coexisted in strain CT25, and a different pathway would be triggered by various MXs. Demethylation dominated in the degradation of N-7-methylated MXs (such as 7-methylxanthine, theobromine, and caffeine), where C-8 oxidation was the major pathway in the catabolism of 1-methylxanthine, whereas demethylation and C-8 oxidation are likely both involved in the degradation of theophylline. Enzymes responsible for MX degradation were located inside the cell. Both cell culture and cell-free enzyme assays revealed that N-1 demethylation might be a rate-limiting step for the catabolism of the MXs. Surprisingly, accumulation of uric acid was observed in a cell-free reaction system, which might be attributed to the lack of activity of uricase, a cytochrome c-coupled membrane integral enzyme.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.296-301
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• 2015

Chronic kidney diseases are based on uncontrolled immunological and inflammatory responses to pathophysiological renal circumstances such as glomerulonephritis, which is caused by immunological mechanisms of glomerular inflammation with increased production of renal pro-inflammatory cytokines. Pentoxifylline (PTX) exhibits anti-inflammatory properties by inhibiting cytokine and chemokine production through aggregation of erythrocytes and thrombocytes. We synthesized a series of 1,7-substituted methylxanthine derivatives by the Traube purine reaction, and the formation of purine ring was completed through nitrosation, a reduction of the nitroso to the amine by catalytic hydrogenation as derivatives of PTX. Then we studied biological activities such as renal anti-inflammatory effects of the synthesized compounds in the production of cytokines such as nitric oxide (NO), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) and of chemokines such as monocyte chemoattractant protein-1 and IL-8 in Raw 264.7 and HK-2 cells. Renal antiinflammatory activities of this novel series of N-1 and N-7-substituted methylxanthine showed that the N-7 methyl-group-substituted analogs (S7b) showed selective 61% and 77% inhibition of the production of NO and IL-8. The other replacement of the N-1-(CH₂)₄COCH₃ roup, as in the case of compound S6c, also showed an effective 50% and 77% inhibition of TNF-α and IL-8 production in LPS-stimulated Raw 264.7 and HK-2 cells.

• Journal of Plant Biotechnology
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• 제4권3호
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• pp.91-94
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• 2002

An efficient molecular breeding technique for coffee plants was developed. In order to produce transgenic coffee plants, we established a model transformation procedure via Agrobacterium method. We isolated a gene encoding a protein possessing 7-methylxanthine methyltransferase (theobromine synthase) activity, and it was designated as Coffea arabica 7-methylxanthine methyl transferase; CaMXMT. Using this clone, we produced transgenic coffee plants, in which the expression of CaMXMT is suppressed by double-stranded RNA interference (RNAi) andlor anti-sense methods. The expression pattern of CaMXMT was analyzed by reverse transcription-PCR method and we found that, in the transformed cell lines, the level of transcripts were obviously suppressed by RNAi. The endogenous level of caffeine in the transformed cells was dramatically reduced in comparison with non-transformed cells.

• 대한약침학회지
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• 제19권4호
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• pp.312-318
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• 2016

Objectives: Bacterial resistant infections have become a global health challenge and threaten the society's health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus (S. aureus) and the standard strain of Pseudomonas aeruginosa (P. aeruginosa). Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interactions of green tea extract, epigallate catechin, epigallocatechin gallate, two types of methylxanthine, caffeine, and theophylline with gentamicin were studied in vitro by using a checkerboard method and calculating the fraction inhibitory concentration index (FICI). Results: The MICs of gentamicin against bacterial strains were in the range of $0.312-320{\mu}g/mL$. The MIC values of both types of catechins were $62.5-250{\mu}g/mL$. Green tea extract showed insufficient antibacterial activity when used alone. Methylxanthines had no intrinsic inhibitory activity against any of the bacterial strains tested. When green tea extract and catechins were combined with gentamicin, the MIC values of gentamicin against the standard strains and a clinical isolate were reduced, and synergistic activities were observed (FICI < 1). A combination of caffeine with gentamicin did not alter the MIC values of gentamicin. Conclusion: The results of the present study revealed that green tea extract and catechins potentiated the antimicrobial action of gentamicin against some clinical isolates of S. aureus and standard P. aeruginosa strains. Therefore, combinations of gentamicin with these natural compounds might be a promising approach to combat microbial resistance.

• 대한약리학회지
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• 제26권1호
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• pp.83-90
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• 1990

Cimetidine이 theophylline의 약동학적 특성과 대사과정에 미치는 효과를 검토코자 6마리의 개를 대상으로 일주일간 정맥내 cimetidine(30mg/kg/day)투여 전후에 단일 용량의 정맥투여에 따른 theophylline의 약동학적 parameter 및 뇨중 theophylline 대사물 배설의 변화를 교차 실험을 통하여 관찰하였다. 대조실험에 비해 cimetidine투여후 theophylline의 청소율은 평균 31%(P<0.05)감소하였고 혈장반감기는 29%(P<0.01)연장되었다. 그러나 steady-state의 분포용적 및 혈장 단백 결합의 변화는 관찰할 수 없었다. Theophylline의 주 대사물인 3-methylxanthine, 1-methyluric acid 및 1,3-dimethyluric acid의 24시간 뇨증 배설량은 cimetidine투여후 모두 감소 하였으나 통계적으로 유의한 변화는 아니었으며 개별대사물의 배설 분획은 변화가 없었다. 이상의 결과로 부터 cimetidine이 theophylline의 demethylation과 8-hydroxylation대사과정 모두를 비선택적으로 억제함으로써 청소율을 감소시키고 반감기를 증가시킬 것으로 추정되었다.

• 한국수정란이식학회지
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• 제27권3호
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• pp.163-169
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• 2012

The 3-isobutyl-1-methylxanthine (IBMX) is non-selective phosphodiesterase and is able to prevent resumption of meiosis by maintaining elevated cyclic AMP (cAMP) concentrations in the oocyte. The present study was conducted to analyze: (1) nuclear maturation (examined by the Hoechst staining), (2) whether cytoplasmic maturation (examined by the intracellular glutathione (GSH) concentration) of porcine oocytes is improved during meiotic arrest after prematuration (22 h) with IBMX. Before in vitro maturation (IVM), oocytes were treated with 1 mM IBMX for 22 h. After 22 h of pre-maturation, the higher rate of IBMX treated group oocytes were arrested at the germinal vesicle (GV) stage (42.3%) than control IVM oocytes (10.1%). It appears that the effect of IBMX on the resumption of meiosis has shown clearly. In the end of IVM, the reversibility of the IBMX effect on the nuclear maturation has been corroborated in this study by the high proportions of MII stage oocytes (72.5%) reached after 44 h of IVM following the 22 h of inhibition. However, intracellular GSH concentrations were lower in the oocytes treated with IBMX than the control oocytes (6.78 and 12.94 pmol/oocyte, respectively). These results demonstrate that cytoplasmic maturation in porcine oocytes pre-treated with IBMX for 22 h did not equal that of control oocytes in the current IVM system. These results indicate that pre-maturation with IBMX for 22 h may not be beneficial in porcine IVM system.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.171-180
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• 2021

Caffeine, a methylxanthine analog of purine bases, is a compound that is largely consumed in beverages and medications for psychoactive and diuretic effects and plays many beneficial roles in neuronal stimulation and enhancement of anti-tumor immune responses by blocking adenosine receptors in higher organisms. In single-cell eukaryotes, however, caffeine somehow impairs cellular fitness by compromising cell wall integrity, inhibiting target of rapamycin (TOR) signaling and growth, and overriding cell cycle arrest caused by DNA damage. Among its multiple inhibitory targets, caffeine specifically interacts with phosphatidylinositol 3-kinase (PI3K)-related kinases causing radiosensitization and cytotoxicity via specialized intermediate molecules. Caffeine potentiates the lethality of cells in conjunction with several other stressors such as oxidants, irradiation, and various toxic compounds through largely unknown mechanisms. In this review, recent findings on caffeine effects and cellular detoxification schemes are highlighted and discussed with an emphasis on the inhibitory interactions between caffeine and its multiple targets in eukaryotic microorganisms such as budding and fission yeasts.

• Toxicological Research
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• 제13권1_2호
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• pp.117-125
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• 1997

In order to assess the possibility whether CYP2D is involved in caffeine metabolism, we have purified and characterized the rat liver microsomal cytochrome P4502D1 (CYP2D1), equivalent to CYP2D6 in human liver, and have utilized the reconstituted CYP2D1 in the metabolism of 4 primary caffeine (1, 3, 7-trimethylxanthine) metabolites such as paraxanthine (1, 7-dimethylxanthine), 1, 3, 7-trimethylurate, theophylline (1, 3-dimethylxanthine) and theobromine (3, 7-dimethylxanthine). Rat liver CYP 2D1 has been purified to a specific content of 8.98 nmole/mg protein (13.4fold purification, 1.5% yield) using $\omega$-aminooctylagarose, hydroxlapatite, and DE52 columns in a sequential manner. As judged from sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the purified CYP2D1 was apparently homogeneous. Molecular weight of the purified CYP2D1 was found to be 51, 000 Da. Catalytic activity of the purified and then reconstituted CYP2D1 was confirmed by using bufuralol, a known subsFate of CYP2D1. The reconstituted CYP2D1 was found to produce to 1-hydroxylbufuralol at a rate of 1.43$\pm$0.13 nmol/min/nmol P450. The kinetic analysis of bufuralol hydroxylation indicated that Km and Vmax values were 7.32$\mu M$ and 1.64 nmol/min/nmol P450, respectively. The reconstituted CYP2D1 could catalyze the 7-demethylation of PX to 1-methylxanthine at a rate of 12.5 pmol/min/pmol, and also the 7- and 3- demethylations of 1, 3, 7-trimethylurate to 1, 3-dimethylurate and 1, 7-dimethylurate at 6.5 and 12.8 pmol/min/pmol CYP2D1, respectively. The reconstituted CYP2D1 could also 3-demethylate theophylline to 1-methylxanthine at 5 pmol/min/pmol and hydroxylate the theophylline to 1, 3-dimethylurate at 21.8 pmol/min/pmol CYP2D1. The reconstituted CYP2D1, however, did not metabolize TB at all (detection limits were 0.03 pmol/min/pmol). This study indicated that CYP2D1 is involved in 3-and 7-demethylations of paraxanthine and theophylline and suggested that CYP2D6 (equivalent to CYP2D1 in rat liver) present in human liver may be involved in the secondary metabolism of the primary metabolites of caffeine.

• 한국동물학회지
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• 제34권2호
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• pp.181-187
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• 1991

양서류 여포를 배양할 때 외부에서 cAMP를 첨가하면 호르몬에 의한 난자의 성숙이 억제된다는 많은 보고가 있었다. 그러나 실제 외부의 cAMP가 여포내로 들어간다는 보고는 아직 없다. 본 연구에서는 배양액내의 cAMP가 여포내로 침투해 들어가는 현상과 들어간 cAMP의 분해과정을 radioimmunoassay로 조사하였다. 개구리 여포를 배양하면서 배양액에 난자의 성숙을 억제하는 농도의cAMP(2.5 mM)를 첨가한 후 일정시간 간격으로 여포내 축척된 cAMP의 농도를 조사한 결과 2시간에서 이미 기본수준(여포당 약 3 p mole)의 수십배로 증가하였다.(여포당 90 p mole). cAMP를 포함한 배양액에서 6시간 배양 후 보통 배양액으로 옮겨 배양하면서 일정 시간마다 여포내 cAMP의 농도를 측정한 결과 6시간 내에 cAMP농도가 여포당 160 p mole에서 약 10 p mole로 급격히 낮아졌다. 그러나 18시간 후에도 기본 수준으로까지 내려가지는 않았다. 이러한 cAMP의 감소과정이 progesterone이나 isobuty methylxanthine (IBMX)에 크게 영향을 받지 않았다. 배양중인 여포를 forskolin(9 u m)으로 자극했을 때에는 기본 수준의 약 3배정도로 cAMP의 농도가 증가하였다. 본 결과는 배양액내의 cAMP가 여포내로 투과해 들어가고 이들은 곧 여포에 의해 분해된다는 것을 시사하고 있다.