Reductases induction

Quinone reductase induction. Acetonitrile extract of the dried root, in cell culture at a concentration of 7.9 mg/g, was active on Hematoma-Mouse-lClC7. The sample was assayed for the induction of detoxifying enzymes that may have anticarcinogenic activity . 

Su, B.-N. et al. Activity-guided isolation of the chemical constituents of Muntingia calabura using a quinone reductase induction assay, Phytochemistry, 63, 335, 2003. 

Hamat, H.B., Kleinhofs, A. Warner, R.L. (1989). Nitrate reductase induction and molecular characterization in rice (Oryza sativa L.). Molecular and General Genetics 218, 93-8. 

Activity-monitored fractionation of a chloroform-soluble extract of Deprea subtriflora using a quinone reductase induction assay led to the C-18 norwithanolides mentioned previously. Six of the active compounds obtained from this plant (44, 46, 47, 49, 52 and 53), presentes an a,P-unsaturated ketone unit in ring A. Compound 55 -with a doubly unsaturated ring A ketone- was found to be inactive in the QR assay, while compound 54 was active [72]. It has been suggested that the presence of an a,p-unsaturated ketone unit in ring A of withanolides is important for inducing activity in the cell-based QR induction assay,... 

In bacteria, with Pichinoty type A dissimilatory nitrate reductase, induction of the enzyme occurs only under anaerobic conditions, and occasionally anaerobiosis is sufficient to trigger formation in the absence of nitrate (Schulp Md Stouthamer, 1970 Sinclair and White, 1970). However, in these cases of induction by anaerobiosis, the level of enzyme production is greatly enhanced by the presence of nitrate. Dissimilatory nitrate reductase may also be induced under anaerobic conditions by nitrite and azide. 

P-450 or P-450 reductase, induction responses, spectral and binding studies, and microsomal (endoplasmic reticulum) location and requirement for NADPH, O2 etc. (Burke 1981). The induction of a specific isoenzyme of cytochrome P-450 can be detected in crude microsomal preparations by antibodies or MFO reactions specific to that isoenzyme, e.g. the 3-methylcholanthrene (3MC)-inducible type (P4501A subfamily) is detected by the ethoxyresorufin 0-deethylase (EROD) assay (Phillipson et al. 1984,1985 Stegeman et al. 1986). The presence of more than one isoenzyme of cytochrome P-450 in crude microsomes can result in multiphasic kinetics towards a particular substrate, e.g. 7-ethoxycoumarin O-deethylase activity (ECOD) (Lu and West 1980). 

A series of withanolides was evaluated by Su and coworkers for their ability to stimulate quinine reductase induction with cultured mouse hepatoma, Hepa lclc7 cells. It was found that philadelphicalactones A (68) and B (69), ixocarpalactones A (11) and B (70), withaphysacarpin (71), 18-hydroxywithanolide D (72) and withanone (73), subtrifloralactones A (74) and F (75), subtrifloralactones K (76) and L (77), and 3/i-hydroxymethylsubtrifloralactone E (78) are effective inducers of quinine reductase enzyme [64, 88-90]. Gu and coworkers also evaluated the significant quinine reductase potential of 2,3-dihydro-3)S-methoxyixocarpalactone A (79), 2,3-dihydro-3j -methoxyixocarpalactone B (80), 2,3-dihydroixocar-palactone-B (81), and 4)S,7)S,20/ -trihydroxy-l-oxo-with a-2,5 diene-22,26-oUde (82) for their ability to induce quinine reductase in Hepa lclc7 cells [23]. 

Gu JQ, Li W, Kang YH, Su BN, Fong HH, Van BRB, Pezzuto, Kinghom JM (2003) Minor withanolides born Physalis philadelphica structures, quinine reductase induction activities, and liquid chromatography (LC)-Ms-Ms investigation as artifacts. Chem Pharm Bull 51 530-539... 

Lopez-Torres, M., Perez-Campo, R., Fernandez, A., Barba, C., and Barja de Quiroga, G., 1993a, Brain glutathione reductase induction increases early survival and decreases lipofuscin accumulation in aging frogs. J. Neurosci. Res. 34 233-242. 

T A and H Kalayeh 1991. Applications of Neural Networks in Quantitative Structure-Activity ationships of Dihydrofolate Reductase Inhibitors, journal of Medicinal Chemistry 34 2824-2836. ik M and R C Glen 1992. Applications of Rule-induction in the Derivation of Quantitative icture-Activity Relationships. Journal of Computer-Aided Molecular Design 6 349-383. 

Riendeau, D., and Meighen, E. A. (1980). Co-induction of fatty acid reductase and luciferase during development of bacterial bioluminescence. J. Biol. Chem. 255 12060-12065. 

WALLiGM A, KINGSTON s, STAACK R and JEFFEREY E H (1998) Induction of rat pancreatic glutathione S-transferase and qitinone reductase activities by a mixture of glucosinolate breakdown derivatives foimd in Brussels sprouts . Food Chem Toxicol, 36 365-73. 

R. Welch, W. Norvell, S. Schaefer, J. Shaff, and L. Kochian, Induction of iron (111) and copper (11) reduction in pea Pisiim. sativum L.) roots by Fe and Cu status. Does the root-cell plasma Fe(lll) reductase perform a general role in regulating cation uptake Planta 190 555 (1993). 

Saito et al. (134) found that the cytosolic nitroreductase activity was due to DT-diaphorase, aldehyde oxidase, xanthine oxidase plus other unidentified nitroreductases. As anticipated, the microsomal reduction of 1-nitropyrene was inhibited by 0 and stimulated by FMN which was attributed to this cofactor acting as an electron shuttle between NADPH-cytochrome P-450 reductase and cytochrome P-450. Carbon monoxide and type II cytochrome P-450 inhibitors decreased the rate of nitroreduction which was consistent with the involvement of cytochrome P-450. Induction of cytochromes P-450 increased rates of 1-aminopyrene formation and nitroreduction was demonstrated in a reconstituted cytochrome P-450 system, with isozyme P-448-IId catalyzing the reduction most efficiently. 

Disulfoton induced the liver MFO system in animals (Stevens et al. 1973). In the same study, exposure to disulfoton orally for 3 days also increased ethylmorphine N-demethylase and NADPH oxidase activities, but had no effect on NADPH cytochrome c reductase. Thus, the induction of the MFO system required repeated dosing with relatively high doses. Furthermore, these changes are not specific for disulfoton exposure, and these subtle liver effects require invasive techniques in humans to obtain liver tissue for performance of these enzyme assays. 

Pappolla MA, Omar RA, Chyan YJ, Ghiso J, Hsiao K, et al. 2001. Induction of NADPH cytochrome P450 reductase by the Alzheimer beta-protein. Amyloid as a foreign body. J Neurochem 78 121-128. 

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