Based on the target occupancy mathematical model, the binding kinetic process of potential active ingredients of lowering uric acid in Chrysanthemum morifolium with xanthine oxidase(XOD) was evaluated. The potential active ingredients of lowering uric acid in Ch. morifolium were screened by UPLC-Q-Exactivems MS technology, reference substance identification and in vitro enzymatic kinetics experiments. The binding kinetic parameters of xanthine oxidase and potential inhibitor in Ch. morifolium were determined by surface plasma resonance(SPR). The verified mathematical model of the XOD target occupancy evaluated the kinetic binding process of inhibitors and xanthine oxidase in vivo. According to UPLC-Q-Exactive MS and reference substance identification, 39 potential uric acid-lowering active ingredients in Ch. morifolium extracts were identified and the inhibitory activities of 23 compounds were determined. Three potential xanthine oxidase inhibitors were screened, namely genistein, luteolin, and apigenin. whose IC_(50 )were 1.23, 1.47 and 1.59 μmol·L~(-1), respectively. And the binding rate constants(K_(on)) were 1.26×10~6, 5.23×10~5 and 6.36×10~5 mol·L~(-1)·s~(-1), respectively. The dissociation rate constants(K_(off)) were 10.93×10~(-2), 1.59×10~(-2), and 5.3×10~(-2 )s~(-1), respectively. After evaluation by different administration methods, the three selected compounds can perform rapid and sustained inhibition of xanthine oxidase in vivo under combined administration. This study comprehensively evaluated the target occupancy process of three effective components in different ways of administration in vivo by UPLC-MS, concentration-response method, SPR technology and xanthine oxidase target occupancy model, which would provide a new research idea and method for screening active ingredients in traditional Chinese medicine.
Chromatography, Liquid ; Chrysanthemum ; Flavonoids ; Kinetics ; Pharmaceutical Preparations ; Tandem Mass Spectrometry ; Xanthine Oxidase/metabolism*

OBJECTIVETo evaluate the antioxidant activities of different chemical constituents from Astragalus mongholicus Bunge and their protection against xanthine (XA)/xanthine oxidase (XO)-induced toxicity in PC12 cells.

METHODSThe compounds of Astragalus mongholicus Bunge were isolated by chromatography and the structures were elucidated on the basis of spectral data interpretation. Their antioxidant activities were detected by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities in a cell-free system. Meanwhile, the effects against XA/XO-induced toxicity were assessed using MTT assay in PC12 cells.

RESULTSTen principal constituents were isolated and identified as formononetin (I), ononin (II), calycosin (III), calycosin-7-O-beta-D-glucoside (IV), 9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (V), adenosine (VI), pinitol (VII), daucosterol (VIII), beta-sitoster (IX) and saccharose (X) from Astragalus mongholicus Bunge. The compounds I, III, and IV scavenged DPPH free radicals in vitro. Formononetin and calycosin were found to inhibit XA/XO-induced cell injury significantly, with an estimated EC50 of 50 ng/mL.

CONCLUSIONCompound II, VI, and VII are first reported in this plant. Calycosin exhibits the most potent antioxidant activity both in the cell-free system and in the cell system.

Animals ; Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Free Radical Scavengers ; chemistry ; pharmacology ; Free Radicals ; metabolism ; Isoflavones ; chemistry ; pharmacology ; PC12 Cells ; Rats ; Xanthine ; toxicity ; Xanthine Oxidase ; toxicity

OBJECTIVETo investigate the protection effects of electroacupuncture on injury of lipid peroxidation induced by liver ischemia in septic rats.

METHODSForty-eight male SD rats were subjected to sepsis induced by cecal ligation and puncture (CLP), and were randomly divided into a Sham operation group (group A), a CLP model group (group B), a CLP model plus electroacupuncture at "Zusanli" (ST 36) group (group C), a CLP model plus electroacupuncture at the shame acupoint (group D), a vagotomy plus CLP model group (group E) and CLP model plus electroacupuncture group after vagotomy (group F), 8 rats in each group. CLP was performed in group E and group F after the abdominal vagotomy. Bilateral "Zusanli"(ST 36) points and the shame acupoint were electroacupunctured (2 mA, 2/100 Hz) for 1 hour in group C, group F and group D, respectively. The hepatic blood flow (HBF) was detected by a laser-Doppler flowmetry at 6 h after CLP. The plasma activity of alanine aminotransferase (ALT) was also determined and specimens of liver were harvested for evaluation of malondialdehyde (MDA), xanthine oxidase (XOD) and assessment of the rate of water content.

RESULTSThe blood flow of the liver was (56.97 +/- 11.95) U in group C which was significantly lower than (80.12 +/- 19.57) U in group A but higher than (42.61 +/- 10.97) U in group B, (44.53 +/- 9.23) U in group D, (30.05 +/- 4.46) U in group E and (30.46 +/- 6.38) U in group F (all P < 0.05) 6 h after CLP. Meanwhile, the levels of MDA, XOD, ALT and the rates of water content in liver in group C were all significantly higher than those in group A, but lower than those in the other four groups (all P < 0.05). The levels of MDA, XOD, ALT and the rates of water content in liver in group E and group F were all significantly higher than those in group D (all P < 0.05), while the blood flow of the liver lower than that in group D (P < 0.05), and with no significant differences in all above measurements between group E and group F (all P > 0. 05).

CONCLUSIONElectroacupuncture at "Zusanli" (ST 36) can promote hepatic blood flow, inhibit lipid peroxidation and alleviate hepatic edema and dysfunction in septic rats, which might be related with the completeness of cranial nerve.

Alanine Transaminase ; blood ; Animals ; Electroacupuncture ; Lipid Peroxidation ; Liver Circulation ; Male ; Rats ; Rats, Sprague-Dawley ; Sepsis ; physiopathology ; therapy ; Xanthine Oxidase ; metabolism

Eight compounds,(R)-2-[5-(methoxycarbonyl)-4-methyl-6-oxo-3,6-dihydro-2H-pyran-2-yl]acetic acid(1),(3S,4R)-3,4-dihydro-3,4-epoxy-5-hydroxynaphthalen-1(2H)-one(2),(-)-mitorubrinol(3),(-)-mitorubrin(4),(±)-asperlone A(5), terreusinone(6), verrucisidinol(7) and cerebroside C(8) were isolated from the endophytic fungus Talaromyces purpurogenus by using various column chromatographic techniques. Their structures were identified by NMR, MS, CD and optical rotation. Compounds 1 and 2 were new compounds. Their anti-diabetic activities in vitro were evaluated, and compound 1 showed moderate inhibitory activity toward XOD at 10 μmol·L~(-1) with the inhibition rate of 69.9%.
Endophytes/chemistry* ; Hypoglycemic Agents/chemistry* ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Secondary Metabolism ; Talaromyces/chemistry* ; Tylophora/microbiology* ; Xanthine Oxidase/antagonists & inhibitors*

AIMTo explore the role of ligustrazin on dynamic changes of lipid peroxidation in hepatic ischemia/reperfusion injury (HIRI) and its mechanism.

METHODSThe HIRI model was used. Twenty rabbits were randomly divided into control group (n = 10) and ligustrazin group (n = 10). The xanthine oxidase (XO) activity, superoxide dismutase (SOD) activity,malondialdehyde (MDA) content and glutamic pyruvic transaminase (GPT) activity in plasma were observed before ischemia and at ischemia 25 min, reperfusion 25 min, reperfusion 60 min and reperfusion 120 min.

RESULTSThe XO activity, SOD activity, MDA content and GPT activity of ligustrazin group, as compared with control group, showed significant differences (P < 0.05 or P < 0.01) at total time points of reperfusion.

CONCLUSIONLigustrazin has notable anti-lipid peroxidation effect on HIRI, which is due to its inhibiting the generation of oxygen free radicals and its strengthening scavenging of oxygen free radicals.

Alanine Transaminase ; metabolism ; Animals ; Female ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; metabolism ; Male ; Malondialdehyde ; blood ; Pyrazines ; pharmacology ; Rabbits ; Reperfusion Injury ; metabolism ; Superoxide Dismutase ; metabolism ; Xanthine Oxidase ; metabolism

The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.
Animals ; Chlorodiphenyl (54% Chlorine) ; toxicity ; Hypoxanthine ; toxicity ; Isoflavones ; pharmacology ; Male ; Malondialdehyde ; metabolism ; Mice ; Mice, Inbred ICR ; Oxidation-Reduction ; Testis ; drug effects ; metabolism ; Xanthine Oxidase ; toxicity

BACKGROUND: Major hepatic surgery often requires temporary occlusion of the portal triad in order to minimize intraoperative bleeding. The Occlusion of portal triad may induce hepatic ischemia-reperfusion injury. Hepatic hypothermia is intended to suppress hepatic metabolism by lowering the liver temperature, to reduce oxygen consumption, and to minimize ischemic damage to the liver. This study was undertaken to evaluate the effects of topical cooling following ischemia on the liver. METHODS: Twenty-four New Zealand white rabbits were divided into three groups; group A (n=8) received no clamping, group B (n=8) received only clamping, and group C(n=8) received topical cooling using ice slush during clamping. In group B and C, duration of ischemia was 30 miniutes and duration of reperfusion was 60 minutes. Serum alanine aminotransferase(ALT) and purine nucleoside phophorylase(PNP) were measured immediately before clamping, after 30-minute clamping, and after 60-minute reperfusion. Hepatic tissue adenosine triphosphate(ATP), xanthine oxidase, and malondialdehyde( MDA) plus 4-hydroxyalcenals(4HA) were measured after reperfusion. RESULTS: Group C was topically cooled and reached the lowest level of 23.3 degrees C after 20 minutes of cooling. The results showed that ALT levels were significantly lower in group C than in group B(p<0.01), but PNP levels showed no significant differences between them. ATP levels showed no significant differences among the three groups. Xanthine oxidase and MDA plus 4HA levels were significantly lower in group C than in group B(P<0.01). CONCLUSION: These results suggest that topical cooling has a protective effect on parenchymal cells by reduction of oxygen free radicals produced by xanthine oxidase.
Adenosine ; Adenosine Triphosphate ; Alanine ; Constriction ; Free Radicals ; Hemorrhage ; Hypothermia ; Ice ; Ischemia ; Liver* ; Metabolism ; Oxygen ; Oxygen Consumption ; Rabbits ; Reperfusion ; Reperfusion Injury* ; Xanthine Oxidase

Hyperuricemic patients with gouty arthritis or tophi, a serum uric acid concentration of 8.0 mg/dL or higher, and complications should be treated with urate-lowering drugs. Conventionally, allopurinol is used to treat hyperuricemia and gout, but it is necessary to adjust the dosage according to the degree of renal impairment. Uncommonly, allopurinol may have severe or fatal side effects. The non-purine xanthine oxidase inhibitor febuxostat undergoes hepatic metabolism and may require less dose adjustment in association with renal function. It is considered to be an alternative treatment for hyperuricemic patients with chronic kidney disease. Our experience suggests that low-dose febuxostat is a promising alternative to allopurinol for the treatment of gouty arthritis or tophi in peritoneal dialysis patients.
Allopurinol ; Arthritis, Gouty ; Gout* ; Humans ; Hyperuricemia ; Kidney Failure, Chronic ; Metabolism ; Peritoneal Dialysis ; Peritoneal Dialysis, Continuous Ambulatory* ; Renal Insufficiency, Chronic ; Uric Acid ; Xanthine Oxidase ; Febuxostat

To determine whether oxygen free radicals are responsible for the pathogenesis of the cholestasis induced by ligation of common bile duct (CBD) variables which reflect the hepatic function in the serum, the amount of superoxide radical production, and xanthine oxidase(XO) activity were studied. The activity of serum alanine aminotransferase, bilirubin level in the serum and the amount of superoxide radical production were lower in a CBD ligation with allopurinol treated group than in a CBD ligation without allopurinol treated group. Abnormalities of the microscopic structures were reduced in a CBD ligation with allopurinol treated group than in a CBD ligation without allopurinol treated group. Allopurinol, an inhibitor of XO, prevented the hepatic damage induced by CBD ligation through the inhibition of XO. These experiments demonstrate that oxygen free radicals are responsible for the pathogenesis of the cholestatic liver.
Allopurinol/*pharmacology ; Animal ; Bile Ducts ; Cholestasis/*pathology ; Enzyme Inhibitors/*pharmacology ; Free Radicals ; Ligation ; Liver/*pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Superoxides/metabolism ; Xanthine Oxidase/analysis/*antagonists & inhibitors

Animals ; Chronic Disease ; Febuxostat ; Heart Failure ; drug therapy ; metabolism ; Humans ; Reactive Oxygen Species ; Thiazoles ; pharmacology ; therapeutic use ; Xanthine Oxidase ; antagonists & inhibitors