In vitro conversion of pteroylglutamic acid to citrovorum factor by rat liver enzymes

2-Methylpapaverinium iodide (I), 2'-hydroxymethyl-2-methylpapaverinium iodide (IX), and 2-methyl-3,4-dihydropapaverinium iodide (X. CH3I) form pseudobase by addition of hydroxide ions to the C(1)=N(+) bond. 2'-Hydroxymethyl-2-methyl-3,4-dihydropapaverinium iodide (XV) and 2'-hydroxymethyl-2-methyl-9-oxo-3,4-dihydropapaverinium iodide (XVI) react with hydroxide ions in aqueous medium under formation of cyclic pseudobases XVII and XVIII. The equilibrium constants (KR+) of pseudobase formation have been measured in aqueous ethanol (1 : 1 w/w, 25°C, ionic strength 0.1). The quaternary papaverinium derivatives are metabolized to isoquinilones and carbonyl compounds by means of rat liver enzymes. The role of pseudobases in these biotransformations has been discussed and biogenetic conclusions have been drawn.

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Antioxidant properties of Resveratrol on Acetaminophen induced toxicity in Wistar Rat liver and HepG2 Cells

Avicenna Journal of Medical Biochemistry ◽

10.15171/ajmb.2017.15 ◽

2017 ◽

Vol 5 (2) ◽

pp. 81-86 ◽

Cited By ~ 3

Author(s):

Ebrahim Abbasi Oshaghi ◽

Mona Pourjafar ◽

Seyde Somayeh Mirzajani ◽

Roohollah Mohseni ◽

Mehrnoosh Mousavi ◽

...

Keyword(s):

Rat Liver ◽

Hepg2 Cells ◽

Liver Enzymes ◽

Antioxidant Properties ◽

Wistar Rat ◽

Protein Carbonyl ◽

Protein Carbonyl Content ◽

Tnf Α

Background: Although acetaminophen (APAP) is considered safe at therapeutic doses, intake of high amounts of this drug can cause liver failure. In the present experiment, we examined the hepatoprotective effects of resveratrol (RES) in HepG2 cells and rat liver. Objectives: This study aimed to evaluate the influence of RES on liver function in rat model of necrosis and HepG2 cells. Materials and Methods: In this study, rats were randomly assigned into 4 groups (7 rats in each group) as follows; group 1: control rats (received normal saline), group 2: hepatotoxic control (control rats that received 640 mg/kg/d APAP), group 3: positive control (received 150 mg/kg N-acetylcysteine), group 4: RES (received 30 mg/kg RES). The animals were treated for 7 days. Afterwards, the levels of liver enzymes, protein carbonyl content, glutathione (GSH) level, and Tumor necrosis factor (TNF-α) level were determined. Results: In the in vitro experiment, APAP-induced HepG2 cells were treated with RES at different concentrations and various factors such as cell viability, liver enzymes, GSH and TNF-α levels were measured. Conclusions: Our results indicated that RES could normalize all these factors in vitro and in vivo (P<0.05). In fact, RES had potential hepatoprotective effect against APAP -induced hepatotoxicity in HepG2 cells and animal models mainly via dual change of oxidative stress and cytokine levels.

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The synthesis of pteroylpolyglutamates by sheep liver enzymes in vitro

Biochemical Journal ◽

10.1042/bj1360295 ◽

1973 ◽

Vol 136 (2) ◽

pp. 295-301 ◽

Cited By ~ 43

Author(s):

Jeffrey M. Gawthorne ◽

Richard M. Smith

Keyword(s):

Subcellular Distribution ◽

Microsomal Fraction ◽

Liver Enzymes ◽

Side Chain ◽

Synthetase Activity ◽

Nuclear Fraction ◽

Liver Cytosol ◽

Sheep Liver ◽

Pteroylglutamic Acid

1. Sephadex G-15 was used to separate pteroylmonoglutamates from corresponding polyglutamate derivatives. 2. Pteroylpolyglutamates were formed when 5-formyltetrahydro[2-14C]pteroylglutamic acid, 5-[methyl-14C]tetrahydropteroylglutamic acid or tetrahydro[2-14C]pteroylglutamic acid was incubated at pH8.4 with ATP, MgCl2, KCl, l-glutamic acid and sheep liver cytosol. The γ-glutamyl side chain appeared to be lengthened by the stepwise addition of single glutamate moieties. 3. The subcellular distribution of pteroylpolyglutamates paralleled that of pteroylpolyglutamate synthetase activity, and followed the order cytosol>‘nuclear’ fraction>microsomal fraction>mitochondria.

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