Effect of Alcohol Extract of Oroxylum indicum on Reducing Uric Acid and Protecting Kidney in Hyperuricemia Mice / 中国实验方剂学杂志

ObjectiveTo investigate the effect of alcohol extract of Oroxylum indicum （MHD-80） on reducing uric acid （UA） and protecting the kidney in the hyperuricemia （HUA） model in vivo. MethodPotassium oxazine （350 mg·kg-1） and adenine （80 mg·kg-1） were used to construct an HUA model of mice in vivo to evaluate the mechanism related to UA reduction and the protective effect of renal function of MHD-80. Seventy male ICR mice were randomly divided into seven groups， including the normal group， model group， allopurinol group （5 mg·kg-1）， febusotan group （5 mg·kg-1）， and MHD-80 low-， medium-， and high-dose groups （3， 6， 12 mg·kg-1）， with 10 in each group. Except for the normal group， the other groups were given intragastric administration of potassium oxazine and adenine for 14 consecutive days to establish the HUA model. On the 8th to 14th day after modeling， each group was given corresponding drugs by intragastric administration， once a day. 1 h after the last administration， blood was collected from the eyeballs， and kidney and liver tissues of mice were collected. Serum levels of UA， urea nitrogen （BUN）， and creatinine （Cr） and liver activity of xanthine oxidase （XOD） were determined by enzyme colorimetry. Serum contents of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） were determined by enzyme-linked immunosorbent assay （ELISA）. Hematoxilin-eosin （HE） staining was used to observe the pathological changes in kidney tissues. The protein expression levels of ATP-binding box transporter G2 （ABCG2） and glucose-facilitating transporter 9 （GLUT9） in kidney tissues were detected by Western blot. ResultIn vivo experiment shows that compared with the normal group， the serum levels of UA， Cr， BUN， inflammatory factors TNF-α， IL-1β， and liver XOD activity in the serum of mice in the model group were significantly increased （P<0.05， P<0.01）， and the expression of GLUT9 in kidney tissues was significantly up-regulated （P<0.05）. ABCG2 protein expression was significantly down-regulated （P<0.05）， and renal injury was obvious. Compared with the model group， the levels of UA， BUN， Cr， TNF-α， IL-1β， and liver XOD activity in the serum of mice in the high-dose group of MHD-80 were decreased to different degrees （P<0.05， P<0.01）， GLUT9 protein expression was significantly down-regulated （P<0.01）， ABCG2 protein expression was significantly up-regulated （P<0.05） in the high-dose group of MHD-80， and the degree of renal injury was reduced. ConclusionMHD-80 has certain uric acid reduction， anti-inflammatory， and anti-renal injury effects， which are related to inhibiting XOD activity and regulating the expression of ABCG2 and GLUT9 uric acid transporter.

Research advances in the therapeutic potential of xanthine oxidoreductase inhibitors for periodontitis / 口腔疾病防治

@#Periodontitis is associated with abnormal purine metabolism, which is manifested by increased uric acid in host blood and increased expression of the purine-degrading enzyme, xanthine oxidoreductase (XOR), in periodontal tissues. Both XOR and uric acid are pro-oxidative and pro-inflammatory mediators under pathological conditions. Animal studies have found that injection of uric acid promotes the progression of periodontitis and that febuxostat (an XOR inhibitor) improves tissue destruction in periodontitis. Therefore, blocking the source of uric acid may be a therapeutic strategy to control the progression of periodontitis. In this article, the rationality of XOR inhibitors as potential therapeutic drugs for periodontitis is reviewed. The literature review results suggest that XOR inhibitors show antioxidative, anti-inflammatory, and anti-osteoclastic effects, and XOR inhibitors show clinical efficacy in the treatment of infectious, inflammatory and osteolytic diseases. Although there is no direct evidence to support the finding that XOR inhibitors can ameliorate periodontal microecological dysbiosis, these drugs can modulate intestinal microflora dysbiosis, and there is indirect evidence to support a beneficial effect of XOR inhibitors on periodontal microecological dysbiosis. In conclusion, XOR inhibitors may be used as immunomodulators for the adjuvant treatment of periodontitis by inhibiting inflammation, oxidative stress and anti-osteoclast effects.

Anti-hyperuricemia activity and its mechanism of flavonoid extract from saffron floral bio-residues / 中国中药杂志

A hyperuricemic rat model induced by adenine and ethambutol was established to investigate the anti-hyperuricemia activity and its mechanism of the flavonoid extract from saffron floral bio-residues. Sixty-seven SD rats were randomly divided into control group, model group, positive control group, and flavonoid extract groups(with 3 doses), respectively, and each group contained 11 or 12 rats. The hyperuricemic model was established by continuous oral administration of adenine(100 mg·kg~(-1)) and ethambutol(250 mg·kg~(-1)) for 7 days. At the same time, the positive control group was given allopurinol(20 mg·kg~(-1) per day) and the flavonoid extract groups were given the flavonoid extract at doses of 340, 170 and 85 mg·kg~(-1) per day, respectively. On day 8, rat serum, liver, kidney, and intestinal tissues were collected, and the levels of uric acid in serum and tissue, the xanthine oxidase activities and antioxi-dant activities in serum and liver were evaluated, and the kidney histopathology was explored. In addition, an untargeted serum metabolomics study was performed. According to the results, the flavonoid extract effectively reduced the uric acid levels in serum, kidney and ileum and inhibited the xanthine oxidase activities and elevated the antioxidant activities of serum and liver in hyperuricemic rat. At the same time, it reduced the levels of inflammation factors in kidney and protected renal function. Moreover, 68 differential metabolites of hyperuricemic rats were screened and most of which were lipids and amino acids. The flavonoid extract significantly retrieved the levels of differential metabolites in hyperuricemic rats, such as SM(d18:1/20:0), PC[18:0/18:2(92,12Z)], palmitic acid and citrulline, possibly through the following three pathways, i.e., arginine biosynthesis, glycine, serine and threonine metabolism, and histidine metabolism. To sum up, the flavonoid extract of saffron floral bio-residues lowered the uric acid level, increased the antioxidant activity, and alleviated inflammatory symptoms of hyperuricemic rats, which may be related to its inhibition of xanthine oxidase activity and regulation of serum lipids and amino acids metabolism.

Establishment and application of activity determining methods for different subtypes of xanthine oxidoreductase / 药学学报

Xanthine oxidoreductase (XOR), the key enzyme catalyzing purine to produce uric acid, including two subtypes, xanthine dehydrogenase (XDH) and xanthine oxidase (XO), respectively, in vivo. Usually, XDH and XO can transform to each other. In this study, based on the principle that the subtype XO or XDH uses different electron acceptors, the methods for the measuring the activities of bovine milk XOR (pure enzyme) and its subtypes were established. The optimal concentrations of substrate xanthine (50 μmol·L-1) and electron acceptor NAD+ (50 μmol·L-1), pH value (7.80) were investigated. The ranges of the XOR, XO, XDH activity which could be determined were 0.97-17.5 U·L-1, 1-9 U·L-1, and 66-1 191 mU·L-1, respectively. Furthermore, the methods for determining the activities of XOR and its subtypes in mouse liver were established. The preparation of liver samples, the optimal concentrations of xanthine (100 μmol·L-1) and NAD+ (100 μmol·L-1) were researched. And the activity ranges of XOR, XO and XDH in mouse liver which could be determined were 0.67-3.98, 0.19-1.08, and 0.52-3.55 U·gprot-1, respectively. With the methods above, the effects of classic XOR inhibitor allopurinal (Allo) on XOR, XO and XDH from both milk and mouse liver were determined. All animal experiments have been approved by the Animal Experimental Center, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College (00003346). This study established new methods for the determination of XOR and its subtypes activity in pure enzyme system and in mouse liver, respectively, which were accurate and convenient. It laid the experimental foundation for exploring the different pathophysiological effects of XOR in the body and developing new XOR inhibitors.

Effects of water extract and ethanol extract from the root of Caragana sinica on hyperuricemia in mice / 中国药房

OBJECTIVE To investigat e the effects of water extract （WCS）and ethanol extract （ECS）from the root of Caragana sinica on hyperuricemia （HUA）in mice. METHODS Kunming mice were randomly divided into normal control group ， model group ，allopurinol group （positive control ，5 mg/kg），benzbromarone group （positive control ，7.8 mg/kg），WCS low-dose ， medium-dose and high-dose groups （38，75，150 mg/kg），ECS low-dose ，medium-dose and high-dose groups （50，100，200 mg/kg）， with 10 mice in each group. Except for the normal control group ，the other mice were given potassium oxazinate intraperitoneally and hypoxanthine intragastrically for consecutive 7 d to establish HUA model. On the third day of modeling ，mice in each administration group were given corresponding drugs intragastrically ，and normal control group and model group were given equal volume of normal saline once a day for 5 consecutive days.The body weight of mice were weighted during administration ；one hour after the last administration ，the organ indexes of liver ，kidney and spleen were calculated ；the contents of serum uric acid （SUA）， blood urea nitrogen （BUN）and serum creatinine （SCR）；the activity of xanthine oxidase （XOD）in serum and liver tissue were determined. Relative mRNA and protein expressions of XOD in liver tissue ，relative expre ssions of GLUT9，URAT1 and OAT 1 in renal tissue were all detected ；and the pathological changes of renal tissue were observed. RESULTS There were no significant differences in liver index and spleen index in each group （P＞0.05）. Compared with normal control group ， except for allopurinol group ， there were no significant differences in the body weight and the contents of BUN and SCR in mice of other administration groups （P＞0.05）；the renal index and SUA content of mice in the m odel group and allopurinol group were significantly increased （P＜0.05）；in the model group ，the XOD activity in serum and liver tissue ，the relative mRNA and protein expression of XOD in liver tissue ，the relative expressions of GLUT 9 and URAT 1 protein in renal tissue were significantly increased （P＜0.05），and the relative expression of OAT 1 protein in renal tissue was significantly decreased （P＜ 0.05）. Compared with model group ，renal indexes of mice were decreased significantly in WCS and ECS groups （P＜0.05），and the pathological damage of renal tissue was significantly improved ；SUA content ，XOD activity in serum and liver tissue ，the relative mRNA and protein expression of XOD in liver tissue ，and the relative expression of URAT 1 protein in renal tissue were decreased significantly in administration groups （P＜0.05）. The relative expression of GLUT 9 protein in renal tissue of mice in benzbromarone group and ECS high-dose group decreased significantly （P＜0.05）；relative expression of OAT 1 protein in renal tissue of mice in benzbromarone group ，WCS low-dose and high-dose groups ，ECS low-dose group were increased significantly （P＜0.05）. CONCLUSIONS WCS and ECS can significantly decrease the contents of SUA in HUA model mice ，and improve pathological state of renal tissue ，the mechanism of which may be associated with inhibiting XOD activity and uric acid reabsorption，and down-regulating protein and mRNA expression of XOD.

Analysis of chemical constituents in ethyl acetate extract of Taxilli Herba by UPLC-Q-Exactive-MS and screening of potential xanthine oxidase inhibitors / 中国中药杂志

The present study analyzed and identified the chemical constituents from ethyl acetate(EA) extract of Taxilli Herba with UPLC-Q-Exactive-MS and screened active xanthine oxidase(XO) inhibitors with HPLC. The analysis was performed on an Hypersil GOLD C_(18) reversed-phase column(2.1 mm×50 mm, 1.9 μm), with the mobile phase of water containing 1% formic acid(A) and methanol(B) under gradient elution, the flow rate of 0.3 mL·min~(-1), and the injection volume of 5 μL. ESI source was used for MS and the compounds were collected in positive and negative ion modes. Xcalibur 4.1 was used to analyze the retention time, accurate relative molecular weight, and fragmentation of the compounds. The inhibitory activity of some known compounds on XO was screened by HPLC. Thirty chemical constituents were identified, including phenolic acids and flavonoids by experimental data combined with information of standards, data reported previously, and databases, such as MzCloud and ChemSpider. The activities of 10 chemical components were screened. Gallic acid and naringenin chalcone had strong inhibitory activities on XO with IC_(50) of 57 μg·mL~(-1) and 108 μg·mL~(-1). UPLC-Q-Exactive-MS allows the accurate, rapid, and comprehensive identification of main chemical constituents from Taxilli Herba. Gallic acid and naringenin chalcone may be the active components of XO inhibitors.

Research progress of febuxostat derivatives as xanthine oxidase inhibitors / 药学学报

Febuxostat, as a xanthine oxidase inhibitor, is a classic anti-gout drug with significant therapeutic effects and good tolerability. The structures of febuxostat and its derivatives can be divided into two parts: a substituted phenyl ring and a five-membered or six-membered heterocyclic ring with a carboxyl substitution. This paper reviewed the research progress of febuxostat derivatives in recent ten years and classified the structure-activity relationships of various febuxostat derivatives. Exploring the action mechanisms and structure-activity relationships of xanthine oxidase inhibitors might be significant for the rational design and development of new anti-gout chemical entities.

Simulation Analysis of Occupancy Rates of Baicalein， Quercetin and Galangin on Target Sites of Xanthine Oxidase / 中国实验方剂学杂志

Objective:To simulate the occupancy rates of baicalein， quercetin and galangin on the target sites of xanthine oxidase <italic>in vivo</italic>. Method:In this experiment， the half inhibitory concentration （IC₅₀） of febuxostat， baicalein， quercetin and galangin against xanthine oxidase were determined by <italic>in vitro</italic> enzymatic reaction. Binding free energy was predicted by molecular docking technology and their association rate constant （k_on） and dissociation rate constant （k_off） were determined by surface plasmon resonance technology. Based on measured binding kinetic parameters （k_on and k_off） and extracted pharmacokinetic data， the target occupancy model <italic>in vivo</italic> was established. Result:The IC₅₀values of febuxostat， baicalein， quercetin and galangin were 0.002 7， 1.63， 0.38， 1.59 µmol·L^-1， respectively. The IC₅₀ of febuxostat was very close to that reported in the literature. The predicted curve of target occupancy rate <italic>in vivo</italic> of febuxostat was consistent with its duration of clinical efficacy. When single intragastric administration of long-circulating liposomes of quercetin with dose of 100 mg·kg^-1 in rats， the time of target occupancy rate >70% <italic>in vivo</italic> lasted for about 3.9 h. When rats were orally administered baicalein and galangin with dose of 200 mg·kg^-1， the time of target occupancy rate >50% <italic>in vivo </italic>lasted for about 10 h and 1.7 h， respectively. Conclusion:The prediction model of xanthine oxidase target occupancy constructed by drug target binding kinetics and <italic>in vivo</italic> pharmacokinetic curves can effectively evaluate the <italic>in vivo</italic> inhibitory activity of compounds against the target.

Effect of Different Extracts of Thlaspi Herba on Gut Microbiota of Hyperuricemia Mice / 中国实验方剂学杂志

Objective:To explore the effect of different extracts of Thlaspi Herba on the gut microbiota of hyperuricemia mice， and to reveal the substance basis and mechanism of its hypouricemic activity. Method:Eighty-eight male Kunming mice were divided into 11 groups， including blank group， model group， allopurinol group， high and low dose groups of petroleum ether extract， high and low dose groups of ethyl acetate extract， high and low dose groups of <italic>n</italic>-butanol extract， high and low dose groups of total flavonoids extract. Mice in the blank group were given 0.5% sodium carboxymethylcellulose by gavage， and the other groups were given oteracil potassium （500 mg·kg^-1） by gavage to duplicate the hyperuricemia model. After modeling for several hours， the blank group and the model group were given distilled water by gavage， while mice in the allopurinol group were given allopurinol suspension （50 mg·kg^-1）， and mice in each treatment group were given high and low doses of corresponding extract （5， 2.5 g·kg^-1）. The serum uric acid （SUA） level and xanthine oxidase （XOD） activity were measured after 14 days. Fresh feces were collected for 16S rDNA sequencing. Result:Compared with the blank group， SUA level and XOD activity of model group were significantly increased （<italic>P</italic><0.05）. Compared with the model group， SUA level and XOD activity of the allopurinol group were significantly decreased （<italic>P</italic><0.01）. After intervention， SUA level were significantly decreased （<italic>P</italic><0.05， <italic>P</italic><0.01）， except for high dose and low dose groups of petroleum ether extract and low dose group of total flavonoids extract， XOD activity was significantly inhibited in low dose group of petroleum ether extract， high dose group of total flavonoids extract， and high and low dose groups of <italic>n</italic>-butanol extract （<italic>P</italic><0.05， <italic>P</italic><0.01）. The high dose group of total flavonoids extract was the most significant. The results of flora sequencing showed that <italic>α</italic> diversity and abundance of the model group changed significantly， and Bacteroidetes， Firmicutes and Lactobacillaceae were significantly correlated with XOD activity. After intervention， the operational taxonomic unit （OTU）， ACE， Chao1 and Shannon indexes of the high and low dose groups of total flavonoids extract were significantly increased （<italic>P</italic><0.05， <italic>P</italic><0.01）. Relative abundance of Bacteroidetes in low dose group of ethyl acetate extract， high dose group of total flavonoids extract， and high and low dose groups of <italic>n</italic>-butanol extract was significantly decreased （<italic>P</italic><0.01）， and the relative abundance of Firmicutes was significantly increased （<italic>P</italic><0.01）. The relative abundance of Lactobacillaceae in low dose group of <italic>n</italic>-butanol extract and high dose group of total flavonoids extract was significantly increased （<italic>P</italic><0.01）. Conclusion:The effective part of Thlaspi Herba for reducing uric acid is mainly flavonoids， the improvement of SUA level and XOD activity by affecting gut microbiota such as Lactobacillaceae， Bacteroidetes and Firmicutes， may be one of its mechanisms.

Recent studies on the natural products with xanthine oxidase inhibitory effect / 药学学报

Xanthine oxidase (XOD), catalyzing purine metabolism, is the key enzyme in uric acid (UA) biosynthesis, and becomes an important target for hyperuricemia treatment. The inhibition on XOD plays an important role in the treatment of hyperuricemia-related diseases, such as gout, as well as oxidative stress-induced tissue injury. Here, studies on the natural products with XOD inhibition are reviewed.

The anti-hyperuricemic effects of compound CC18022 targeting xanthine oxidase / 药学学报

Hyperuricemia is not only the biochemical basis of gout, but also closely related to the development of metabolic syndrome, cardiovascular diseases, chronic kidney disease, etc. Xanthine oxidase (XOD) is the key catalytic enzyme for uric acid biosynthesis, therefore the vital target for anti-hyperuricemic drugs. In this study, compound CC18022 was designed and synthesized specifically targeting to XOD. Molecular docking analysis indicated a fairly tight binding between CC18022 and XOD. In the in vitro study, CC18022 significantly inhibited XOD activity with a half maximal inhibitory concentration (IC50) value in the order of nmol·L-1, which is relative to the XOD inhibitor febuxostat. By using both acute and chronic hyperuricemic mice model, compound CC18022 was found to have serum uric acid-lowering effect in a dose-dependent manner in vivo. The animal welfare and experimental processes were in accordance with the provisions of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences. In the acute hyperuricemic mice, CC18022 significantly inhibited serum XOD activity, and also the XOD activity in intestine and liver, which were related to purine absorption and metabolism. Therefore, the novel compound CC18022 exhibited significant inhibition on XOD activity and anti-hyperuricemic effects, making it a favorable candidate for further research.

Determination of inhibitory activity of Salvia miltiorrhiza extracts on xanthine oxidase with a paper-based analytical device / 药物分析学报

A novel paper-based analytical device(PAD)was prepared and applied to determine the xanthine oxi-dase(XOD)inhibitory activity of Salvia miltiorrhiza extracts(SME).First,polycaprolactone was 3D printed on filter paper and heated to form hydrophobic barriers.Then the modified paper was cut according to the specific design.Necessary reagents including XOD for the colorimetric assay were immobilized on two separate pieces of paper.By simply adding phosphate buffer,the reaction was performed on the double-layer PAD.Quantitative results were obtained by analyzing the color intensity with the specialized device system(consisting of a smartphone,a detection box and sandwich plates).The 3D-printed detection box was small,with a size of 9.0 cm x 7.0 cm x 11.5 cm.Color component G performed well in terms of linearity and detection limits and thus was identified as the index.The reaction con-ditions were optimized using a definitive screening design.Moreover,a 10％glycerol solution was found to be a suitable stabilizer.When the stabilizer was added,the activity of XOD could be maintained for at least 15 days under 4℃or-20℃storage conditions.The inhibitory activity of SME was investigated and compared to that of allopurinol.The results obtained with the PAD showed agreement with those ob-tained with the microplate method.In conclusion,the proposed PAD method is simple,accurate and has a potential for point-of-care testing.It also holds promise for use in rapid quality testing of medicinal herbs,intermediate products,and preparations of traditional Chinese medicines.

Study on drug-target binding kinetics profiles of flavonoids in Chrysanthemum morifolium and xanthine oxidase / 中国中药杂志

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.

Protective Antibodies to Bovine Milk Fat Globule and to Xanthine Oxidase Levels in Jordanian Patients with Acute Myocardial Infarction

Background: The previously reported circulating human antibodies against the Bovine Milk Fat Globule Membrane (BMFGM) were found to primarily target xanthine oxidase (XO) enzyme that produces uric acid and reactive oxygen species. It is suggested that XO could potentially be implicated in the pathogenesis of acute myocardial infarction. Methods: In this study, anti-BMFGM and anti-XO IgG, IgM and IgA antibodies were assayed in the sera of acute myocardial infarction patients and healthy control from the Jordanian population using the highly sensitive Enzymelinked immunosorbent assay (ELISA). Results: Serum high in antibodies against xanthine oxidase was used as a reference serum to standardize the assay. The levels of anti-BMFGM IgM antibodies were found to be higher in male controls than myocardial infarction male patients in contrast to female group, but no significant differences were observed in the levels of IgG and IgA antibodies. The levels of anti-xanthine oxidase IgM and IgG antibodies were significantly higher in myocardial infarction patients when compared with their corresponding controls. Conflicting results were obtained when different personnel measured the IgM antibody titres, likely due to infarction factors of IgM aggregation within the assay. Results from this study demonstrate significant differences in the levels of antiMFGM and anti-XO IgM antibodies between myocardial infarction patients and controls. Conclusion: Collectively, the data suggest that XO may be a risk factor in myocardial infarction patients and the presence of antibodies may act as a protective factor

Study on in vitro Inhibitory Activity of the Extracts from 9 Kinds of TCM for Dredging Collaterals and Dispelling Wind on Xanthine Oxidase / 中国药房

OBJECTIVE：To study in vi tro inhibitory act ivities of 9 kinds of TCM for dredging collaterals and dispelling wind on xanthine oxidase （XO），and to screen TCM with outstanding activity. METHODS ：Using xanthine as substrate and xanthinase as reaction enzyme ，allopurinol as positive control ，with water extract and methanol extract （hereinafter referred to as “ethanol extract”）from the stem and leaves of Hedera nepalensis ，the whole plant of Piper wallichii ，the fruits of Rubus corchorifolius ，the root of Caragana sinica ，the root of Wisteria sinensis ，the root of Rubus crataegifolius ，the bark of Catalpa ovata ，the root of Campsis grandiflora ，the stem of P. hancei （hereinafter referred to by plant name ）and petroleum ether ，dichloromethane，ethyl acetate，n-butanol and water fraction of active extract as the objects ，inhibition rate of each sample to XO was detected by spectrophotometry；IC50values were calculated with Graphpad prism 6.0 software to screen active extract/fraction. Double reciprocal method was used to determine the type of enzyme inhibition. RESULTS ：Among 9 kinds of TCM and 18 kinds of the extracts ，the inhibitory rates to XO of 500 μg/mL extracts from each TCM（except for ethanol extract of P. wallichii ），250 μg/mL water extract and ethanol extract of H. nepalensis ，P. wallichii ，R. corchorifolius and P. hancei ，250 μg/mL water extract of C. ovata ，250 μ g/mL ethanol extract of C. sinica ，R. crataegifolius and C. grandiflora ，125 μ g/mL ethanol extract of C. sinica and R. crataegifolius，62.5 μg/mL ethanol extract of C. sinica were more than 50％. The IC 50 value of the ethanol extract from C. sinica was 43.43 μg/mL，which was lower than the extracts of other TCM ，and which was the active extract. The IC 50 values of petroleum ether，dichloromethane，ethyl acetate ，n-butanol and water fracti on of ethanol extract from C. sinica were ＞200，193.35，7.67， 14.80 and ＞200 μg/mL，respectively. The IC 50 value of ethyl XO was competitive-noncompetitive inhibition ， which was different from competi tive inhibition of positive control. CONCLUSIONS：The ethanol extracts of C. sinica ，R. crataegifolius ，P. wallichii ，R. corchorifolius ，P. hancei ，H. nepalensis and the water extracts of H. nepalensis ，P. wallichii ，C. ovata show certain inhibitory activity in vitro to XO ，especially ethanol extract of C. sinica . The ethyl acetate fraction of the ethanol extract of C. sinica has similar inhibitory activity to allopurinol but their inhibition types are different.

Identification of structural analogues xanthine, theophylline and theobromine by surface-enhanced Raman spectroscopy / 药学实践杂志

Objective To distinguish the structural analogues xanthine, theophylline and theobromine by surface-enhanced Raman spectroscopy. Methods Concentrated silver colloid enhancement reagent was prepared as the Raman substrate to increase the number of "hot spots" per unit area, improve the sensitivity of surface-enhanced Raman spectroscopy, enhance the signal strength of the samples and achieve the effective discrimination of structural analogues. Meanwhile, the feasibility of surface-enhanced Raman spectroscopy in practical application was verified by determining serum samples of three mixtures. Results The concentrated silver colloid greatly increased the Raman intensity of the three structural analogues. The spectra of each individual compound and the mixture in the serum system was obtained. The detection limit of the three substances in aqueous solution were 0.005, 0.01 and 0.005 μmol/L respectively. Conclusion Surface-enhanced Raman spectroscopy is a potent technique for distinguishing structural analogues. It is rapid, sensitive and nondestructive to samples. Hence, it can be widely used in the fields of detection, analysis, clinical treatment and diagnosis.

Protective Effect of Polydatin Complicated with Emodin on Hyperuricemia Model Rats with Median Effect Principle / 中国药房

OBJECTIVE：To s tudy the protective effect of polydat in complicated with emodin on hyperuricemia （HUA）model rats，and to screen the optimal complication proportion and investigate the potential mechanism. METHODS ：SD rats were randomly divided into normal control group ，model group ，benzbromarone group （positive control ，8 mg/kg），polydatin alone group，emodin alone group and drug combination group A ，B，C，with 5 rats in each group of each dosage. Normal control group and model group were given constant volume of 0.3％ CMC-Na solution ，administration groups were given relevant medicine intragastrically. Each group was given 0.1 mL/10 g intragastrically once a day ，for consecutive 7 d. Expect for normal control group，other groups were given intraperitoneal injection of potassium oxonate 300 mg/kg 1 h before last medication to induce HUA model. One hour after last medication ，the serum contents of uric acid （UA）were determined in normal control group ，model group，benzbromarone group ，polydatin/alone group （0.625，1.25，2.5，5，10 mg/kg）and drug combination group A [the dose of polydatin+emodin were （0.625+0.625），（1.25+1.25），（2.5+ 2.5），（5 + 5），（10 + 10） mg/kg]. The effect （Fa） and combination index （CI） of above single drug groups and combination groups were calculated by the median effect principle. The dose-effect relationship curves of twocomponents alone or combination were drawn ；Fa-CI curves after simulation were als o drawn to evaluate the effect of two-drug combination. Serum contents of UA in rats were determined and Fa value was calculated in single drug groups and drug combination group B ，C [the dose of polydatin+emodin were （0.625+ 0.625），（0.625+1.25），（0.625+2.5），（0.625+5），（0.625+10）mg/kg and （0.625+0.625），（1.25+0.625），（2.5+0.625），（5+ 0.625），（10+0.625）mg/kg]. The optimal complication proportion of two drugs were screened. The serum contents of xanthine oxidase（XOD）in rats were determined in normal control group ，model group ，benzbromarone group ，polydatin/emodin alone group（10 mg/kg）and the optimal complication proportion groups. The mechanism was analyzed primarily. RESULTS ：Compared with normal control group ，the content of UA in model group was increased significantly （P＜0.01）. Compared with model group ， except for 0.625 mg/kg polydatin alone group ，the content of UA in other administration groups were decreased significantly （P＜ 0.05 or P＜0.01）. When the two drugs were used alone or in combination ，Fa value was positively correlated with drug dose （intercept＞0，correlation coefficient ＞0.9），and Fa value of the combination group was higher than that of any single drug group ； when the simulated Fa value was more than 15％，the corresponding CI value was less than 1，two-drug combination showed synergistic effect. When the complication proportion of polydatin and emodin was 1∶4，the Fa value （53.10）was similar to that of drug combination group A （53.73），and the dose of them were less [ （0.625+2.5）mg/（kg·d）vs.（2.5+2.5）mg/（kg·d）]. Compared with normal control group ，serum content of XOD in model group was increased significantly （P＜0.01）；compared with model group，serum content of XOD in administration groups were decreased significantly ，and the optimal complication proportion group was significantly lower than polydatin alone group and emodin alone group （P＜0.05 or P＜0.01）. CONCLUSIONS ：The polydatin and emodin used alone or in combination can reduce the serum content of UA in HUA model rats by inhibiting the generation of XOD. They have a certain synergistic effect ，and the optimal complication proportion is 1∶4.

In vivo anti-hyperuricemic activity of sesquiterpene lactones from Lychnophora species

ABSTRACT Hyperuricemia is the main cause of gout, an inflammation induced by uric acid deposition in joints. Drugs available present side effects, so there is a need for new treatment alternatives. Lychnophora species are used in folk medicine to treat inflammation, rheumatism and muscle pain. Goyazensolide (10 mg/kg), eremantholide C (25 mg/kg) and lychnopholide (25 mg/kg), sesquiterpene lactones isolated from Lychnophora species were previously studied and showed anti-hyperuricemic effects in mice. However, the mechanisms of this effect were not elucidated. The methodology of this study consisted in treatment of hyperuricemic-induced rats, and comparison between control groups, clinically used anti-hyperuricemic drugs and sesquiterpene lactones. Urine and blood were collected for uric acid quantification. Xanthine oxidase inhibition was measured in liver homogenates. Results showed that all evaluated sesquiterpene lactones presented anti-hyperuricemic activity at the doses of 5 and 10 mg/kg and can act through one or both mechanisms, depending on the dose administrated. Goyazensolide and lychnopholide at dose of 5 mg/kg showed important uricosuric effect. Goyazensolide and lychnopholide at dose of 10 mg/kg, and eremantholide C (5 and 10 mg/kg) presented notable inhibition of hepatic xanthine oxidase activity and uricosuric effect. Thus, these sesquiterpene lactones are promising hypouricemic agent to treat hyperuricemia and gout.

Stimulatory Effects of KPR-A148 on Osteoblast Differentiation and Bone Regeneration

BACKGROUND: Xanthine derivatives have been used to treat a variety of medical conditions including respiratory disease and neural degeneration. However, few studies have reported their effects on bone regeneration. Therefore, we investigated the effects of KPR-A148, a synthetic xanthine derivative on osteoblast differentiation in vitro and bone regeneration in vivo. METHODS: The cytotoxicity of KPR-A148 was evaluated using MC3T3-E1 cells by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltertrazolium bromide assay. The effects of KPR-A148 on osteoblast differentiation were examined by alkaline phosphatase staining, Alizarin red S staining, and real-time PCR of osteoblast differentiation marker genes. To investigate the effects of KPR-A148 on in vivo bone regeneration, a KPR-A148-containing collagen sponge was implanted into a mouse calvarial defect and KPR-A148 was injected twice, weekly. Bone regeneration was evaluated quantitatively by micro-CT and qualitatively by hematoxylin and eosin, as well as Masson's Trichrome staining. RESULTS: KPR-A148 did not show toxicity in the MC3T3-E1 cells and promoted osteoblast differentiation in a concentration-dependent manner. 10 µM of KPR-A148 showed the most significant effect on alkaline phospatase staining and matrix mineralization. KPR-A148 increased the expression of osteoblast marker genes in both the early and late stages of differentiation. In addition, KPR-A148 significantly induced new bone formation in the calvarial defect model. CONCLUSION: These results demonstrate that KPR-A148 strongly induces osteoblast differentiation and new bone formation. Therefore, it could be used as a potential therapeutic agent for regenerating bone following its destruction by disease or trauma.