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1.
Chinese Journal of Biotechnology ; (12): 2838-2849, 2020.
Article in Chinese | WPRIM | ID: wpr-878533

ABSTRACT

(2S)-taxifolin is an important flavonoid that has anti-inflammatory and anti-oxidation effects. It is widely used in pharmaceutical and nutraceutical industries. Flavone 3-hydroxylase (F3H) can catalyze the synthesis of (2S)-taxifolin and other 3-hydroxylated flavonoids from (2S)-eriodictyol. Due to the low catalytic efficiency of F3H, the titer of many 3-hydroxyflavones, such as taxifolin, synthesized by microbial method is relatively low. In this study, a SmF3H was identified from the transcriptome of Silybum marianum (L.) Gaertn. The results of fermentation showed that SmF3H can catalyze the flavone 3-hydroxylation reaction, and its catalytic efficiency was significantly higher than that of commonly used SlF3H from Solanum lycopersicum. Six promoters with different transcription strength were selected to optimize the synthesis pathway from the flavonoid precursor (2S)-naringenin to (2S)-taxifolin. The results showed that the highest titer of (2S)-taxifolin (695.90 mg/L in shake flask) could be obtained when the P(GAL7) promoter was used to control the expression of SmF3H. The titer of (2S)-taxifolin was further improved to 3.54 g/L in a 5-L fermenter, which is the highest titer according to current available literatures.


Subject(s)
Antioxidants , Flavonoids , Milk Thistle , Quercetin/analogs & derivatives
2.
Acta cir. bras ; 34(4): e201900404, 2019. tab, graf
Article in English | LILACS | ID: biblio-1001088

ABSTRACT

Abstract Purpose: To examine the effect of taxifolin on I/R induced gastric injury in rats using biochemical and histopatholohical methods. Methods: Eighteen albino Wistar male rats equally grouped as; gastric I/R (I/R), 50 mg/kg taxifolin + gastric I/R (TAX+ I/R) and sham operation applied (SHAM). Ischemia induced for 1 hour, and reperfusion induced for 3 hours. Results: Oxidant parameters like, Malondialdehyde (MDA) and Hydroxyguanine (8-OHdG) were higher, whereas total glutathione (tGSH) was lower in the I/R group according to SHAM group, histopathological findings such as marked destruction, edema, and proliferated dilated congested blood vessels were observed severely in the I/R group, whereas there was not any pathological finding except mild dilated congested blood vessels in the TAX+ I/R group. Conclusion: The taxifolin can be clinically beneficial in the treatment of gastric injury due to I/R procedure.


Subject(s)
Animals , Male , Rats , Quercetin/analogs & derivatives , Reperfusion Injury/prevention & control , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Gastric Mucosa/injuries , Oxidation-Reduction/drug effects , Quercetin/therapeutic use , Celiac Artery/surgery , Rats, Wistar , Oxidative Stress/drug effects , Disease Models, Animal , Ligation
3.
Acta cir. bras ; 32(8): 633-640, Aug. 2017. graf
Article in English | LILACS | ID: biblio-886223

ABSTRACT

Abstract Purpose: To evaluate the effect of hyperin in cisplatin-induced liver injury in mice. Methods: Mice were pretreated with hyperin at doses of 25 mg/kg and 50 mg/kg, respectively, for six days, and intraperitoneal injection of cisplatin (40 mg/kg) was administrated one hour after the final intragastrication of hyperin. Twenty-four hours later, blood and liver were collected for further research. Results: A single injection of cisplatin (40 mg/kg) for 24 h significantly increased serum alanine and aspartate aminotransferases (ALT/AST) and gamma glutamyl transferase (GGT) activities, whileas hyperin reversed cisplatin-induced such increases. Liver histopathological examination further demonstrated the protection of hyperin against cisplatin-induced liver injury. Further results showed hyperin reversed cisplatin-induced the increase in content of malondialdehyde (MDA) and the decrease in level of total antioxidant capacity (T-AOC) in liver. Moreover, hyperin increased the levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), glutathione-s transferase (GST) in cisplatin-induced liver. Conclusion: Hyperin inhibits cisplatin-induced hepatic oxidative stress, which contributes greatly to the amelioration of cisplatin-induced liver injury in mice.


Subject(s)
Animals , Male , Quercetin/analogs & derivatives , Aspartate Aminotransferases/metabolism , Cisplatin/adverse effects , Chemical and Drug Induced Liver Injury/prevention & control , Antineoplastic Agents/adverse effects , Antioxidants/pharmacology , Quercetin/therapeutic use , Quercetin/pharmacology , Reference Values , Lipid Peroxidation , Catalase/analysis , Random Allocation , Reproducibility of Results , Cisplatin/antagonists & inhibitors , Oxidative Stress/drug effects , Alanine Transaminase/metabolism , Chemical and Drug Induced Liver Injury/pathology , Glutathione/analysis , Glutathione Peroxidase/analysis , Glutathione Transferase/analysis , Liver/drug effects , Liver/enzymology , Liver/pathology , Malondialdehyde/analysis , Mice, Inbred ICR , Antioxidants/therapeutic use
4.
Braz. dent. j ; 25(6): 554-560, Nov-Dec/2014. tab, graf
Article in English | LILACS | ID: lil-732259

ABSTRACT

The aim of this study was to assess, by the three-dimensional finite element method, the influence of crown-to-implant ratio and parafunctional occlusal loading on stress distribution in single external hexagon implant-supported prosthesis. Computer-aided design software was used to confection three models. Each model was composed of a block bone and an external hexagon implant (5x10.0 mm) with screw-retained implant prostheses, varying the height crown: 10, 12.5 and 15 mm. Finite element analysis software was used to generate the finite element mesh and to establish the loading and boundary conditions. Normal (200 N axial and 100 N oblique load) and parafunctional forces (1,000 N axial and 500 N oblique load) were applied. The results were visualized by von Mises and maximum principal stress. In comparison with the normal occlusal force, the parafunctional occlusal force induced an increase in stress concentration and magnitude on implant (platform and first threads) and screw (neck). The cortical bone showed the highest tensile stress under parafunctional force (oblique load). The stress concentration increased as the crown height increased. It was concluded that: increasing the C/I increased stress concentration in both implant components and cortical bone; parafunctional loading increased between 4-5 times the value of stresses in bone tissue compared with functional loading; the type of loading variation factor is more influential than the crown-to-implant factor.


O objetivo deste estudo foi avaliar, através do método dos elementos finitos tridimensionais, a influência do carregamento oclusal parafuncional e da altura da coroa na distribuição das tensões em próteses unitárias implantossuportadas de hexágono externo. Foram confeccionados três modelos com o auxílio de programas de desenho assistido. Cada modelo foi composto por um bloco ósseo da região molar mandibular, por um implante de tipo hexágono externo (5x10,0 mm) e por coroa com diferentes alturas: 10, 12,5 e 15 mm. Os modelos foram exportados para o programa de elementos finitos NEiNastran 9.0, para geração das malhas e estabelecer as condições de contorno. Aplicou-se uma carga funcional (200 N axial e 100 N oblíqua), bem como uma carga parafuncional (1.000 N axial e 500 N oblíqua). Os resultados foram visualizados por meio de mapas de Tensão de von Mises e mapas de Tensão Máxima Principal. O carregamento parafuncional induziu um aumento da área de distribuição e da magnitude das tensões no implante (plataforma e primeiras roscas) e parafuso (pescoço) em comparação com o carregamento funcional. A cortical óssea apresentou maiores áreas de tensão por tração sob carregamento parafuncional oblíquo. A concentração de tensões aumentou à medida que aumentou a altura da coroa. O aumento da altura da coroa induziu um aumento na concentração de tensões, tanto nos componentes do implante, quanto na cortical óssea; o carregamento parafuncional induziu um aumento entre 4-5 vezes da magnitude das tensões no tecido ósseo; o tipo de carregamento apresenta-se como um fator de variação mais influente do que a proporção coroa/implante.


Subject(s)
Animals , Male , Rats , Flavonoids/pharmacology , Hemodynamics/drug effects , Quercetin/pharmacology , /antagonists & inhibitors , Blood Pressure/drug effects , Dioxolanes/pharmacology , Heart Rate/drug effects , Infusions, Intravenous , Injections, Intravenous , Parasympatholytics , Quercetin/analogs & derivatives , Rats, Inbred Strains , Time Factors
5.
Indian J Exp Biol ; 2013 Jan; 51(1): 65-72
Article in English | IMSEAR | ID: sea-147569

ABSTRACT

Antihyperglycemic potential of hyperin at 25 and 50 mg/kg doses for 30 days to streptozotocin induced diabetic rats has been reported. In oral glucose tolerance test, hyperin treated rats showed a significant reduction in blood glucose level after 120 min. It was found that hyperin exhibited dose dependent and significant antihyperglycemic activity in streptozotocin induced diabetic rats which were nearly similar with standard drug glybenclamide. Activities of glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase, glycosylated haemoglobin and level of serum urea and creatinine were significantly decreased in hyperin supplemented diabetic rats, dose dependently. Activities of hexokinase and glycogen synthase were increased with augmentation in liver glycogen, insulin and haemoglobin content in hyperin treated diabetic rats. General hematological parameters did not show any significant change in hyperin treated diabetic rats hence it is safe at these doses. Histopathological studies showed significant morphological changes in pancreatic β-cells of streptozotocin induced diabetic rats. A decreased number of secretory granules of β- cells were observed in diabetic rats and these pathological abnormalities were normalized after treatment with hyperin and standard drug glybenclamide. Further, hyperin decreases significant in serum total cholesterol, triglyceride, low density lipoprotein, very low density lipoprotein levels coupled with elevation of high density lipoprotein in diabetic rats. These results suggest that hyperin has a pivotal role in blood glucose level in streptozotocin induced hyperglycemia by improving the function of pancreatic islets and increasing glycolysis and decreasing gluconeogenesis.


Subject(s)
Animals , Diabetes Mellitus, Experimental/drug therapy , Glucose Tolerance Test , Glyburide/pharmacology , Glycogen/metabolism , Hexokinase/metabolism , Hypoglycemic Agents/pharmacology , Insulin/metabolism , Lipids/chemistry , Liver/metabolism , Male , Models, Chemical , Quercetin/analogs & derivatives , Quercetin/chemistry , Quercetin/metabolism , Quercetin/pharmacology , Rats , Rats, Wistar , Rhododendron/metabolism
6.
Article in English | WPRIM | ID: wpr-57370

ABSTRACT

Quercetin 3-O-beta-(2''-galloyl)-rhamnopyranoside (QGR) is a naturally occurring quercitrin gallate, which is a polyphenolic compound that was originally isolated from Persicaria lapathifolia (Polygonaceae). QGR has been shown to have an inhibitory effect on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. Therefore, this study was conducted to investigate the inhibitory effect of QGR on nitric oxide production and inducible nitric oxide synthases (iNOS) expression in LPS-stimulated Balb/c mice. To accomplish this, 10 mg/kg of QGR was administered via gavage once a day for 3 days. iNOS was then induced by intraperitoneal injection of LPS. Six hours after the LPS treatment the animals were sacrificed under ether anethesia. The serum levels of NO were then measured to determine if QGR exerted an inhibitory effect on NO production in vivo. LPS induced an approximately 6 fold increase in the expression of NO. However, oral administration of QGR reduced the LPS induced increase in NO by half. Furthermore, RT-PCR and western blot analysis revealed that the increased levels of iNOS expression that occurred in response to treatment with LPS were significantly attenuated in response to QGR pretreatment. Histologically, LPS induced the infiltration of polymorphonuclear neutrophils in portal veins and sinusoids and caused the formation of a large number of necrotic cells; however, pretreatment with QGR attenuated these LPS induced effects. Taken together, these results indicate that QGR inhibits iNOS expression in vivo as well as in vitro and has antiinflammatory potentials.


Subject(s)
Animals , DNA Primers , Gene Expression Regulation, Enzymologic/drug effects , Lipopolysaccharides/pharmacology , Liver/drug effects , Mice , Mice, Inbred BALB C , Nitric Oxide/blood , Nitric Oxide Synthase Type II/drug effects , Quercetin/analogs & derivatives , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction
7.
Braz. j. med. biol. res ; 38(7)July 2005. ilus
Article in English | LILACS | ID: lil-403864

ABSTRACT

Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 æg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 æg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6-prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 æg/ml) > quercitrin (0.244 æg/ml) > or = bartericin B (0.244 æg/ml) > bartericin A (0.73 æg/ml) > stigmasterol (0.98 æg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 æg/ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 æg/ml) and high (EC50 <50 æg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied.


Subject(s)
Animals , Antioxidants/pharmacology , Antitrichomonal Agents/pharmacology , Flavonoids/pharmacology , Moraceae/chemistry , Trichomonas/drug effects , Antioxidants/chemistry , Antioxidants/isolation & purification , Antitrichomonal Agents/chemistry , Antitrichomonal Agents/isolation & purification , Drug Evaluation, Preclinical , Flavonoids/chemistry , Flavonoids/isolation & purification , Parasitic Sensitivity Tests , Plant Extracts/pharmacology , Quercetin/analogs & derivatives , Quercetin/pharmacology
8.
Biocell ; 28(3): 311-316, dic. 2004. ilus, tab
Article in English | LILACS | ID: lil-405203

ABSTRACT

Acrosin activity is associated with normal fertility in human and bovine spermatozoa. The aim of the study was to determine the variation of the enzyme activity in the proacrosin-acrosin system in capacitated and acrosome recated cryopreserved bovine sperm. Enzyme activity was assessed spectrophotometrically using N-alpha-benzoyl-DL-arginine p-nitroanilide (BAPNA) as specific substrate for acrosin at pH 8. Capacitation with heparin and quercitin failed to induce conversion of proacrosin to acrosin. An increase in acrosin activity produced by the presence of progesterone, in a dose-dependent manner, was related with the induction of true acrosome reaction. The total level of acrosin activity registered showed that 96 per cent of acrosin of capacitated sperm samples and control is present in the zymogen form. Moreover, progesterone is capable of duplicating the level of active enzyme, indicating that enzyme activity changes are related to acrosome reaction, suggesting that only a minor proportion of the total of proacrosin-acrosin system is required in the exocytotic process on cryopreserved bovine sperm.


Subject(s)
Cattle , Animals , Acrosin/metabolism , Sperm Capacitation/physiology , Spermatozoa , Enzyme Precursors/metabolism , Quercetin/analogs & derivatives , Quercetin/pharmacology , Acrosome Reaction/physiology , Semen/cytology , Trypan Blue/chemistry , Cryopreservation , Chlortetracycline/chemistry , Spermatozoa/enzymology , Spermatozoa/physiology , Heparin/pharmacology , Microscopy, Fluorescence , Microscopy, Interference , Progesterone/pharmacology
9.
Indian J Exp Biol ; 2004 Feb; 42(2): 186-9
Article in English | IMSEAR | ID: sea-61526

ABSTRACT

Two new flavonoids, takakin 7-O-glucoside (1) and (2) bucegin 7-O-glucoside, and six other known compounds (3-8), takakin, isosctullarien, its 7-O-glucoside, takakin 8-O-glucoside, xanthotoxin and esculetin, were separated and identified from Glossostemon bruguieri. The new compounds were characterized using modern spectroscopic techniques, including UV spectroscopy, proton nuclear resonance (1HNMR), carbon thirteen nuclear resonance (13CNMR), homomolecular quantum coherance (HMQC), heteromolecular bonding connectivity (HMBC) and chemical ionization mass spectra (CI). The effect on rats urine volume of the plant powder, its ethanolic extract, (500 mg kg(-1)) along with four of the purified compounds (1,4-6), (100 mg kg(-1)) are described. Eight groups of albino rats (200-300 g body weight) (n=5 for each group) were used in the tests for a one-time treatment, and other seven groups (150-180 g body weight) (n=5 for each group) were tested using the same dose with repeated administration for 15 days. The rat sera were collected and used to determine liver and kidney functions based on alanine amino transferase (ALT) and aspartate amino transferase (AST) for both single and repeated administration. Levels of urea, creatinine and uric acid were determined for both sets of experiments. The toxic effects of both the powder and its alcoholic extract were also studied on mice to determine their LD50, both materials proved to be non-toxic up to 2500 mg kg(-1) body weight.


Subject(s)
Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Body Weight , Creatinine , Flavonoids/chemistry , Glucosides/chemistry , Kidney/drug effects , Liver Function Tests , Plant Extracts/toxicity , Plants, Medicinal/chemistry , Quercetin/analogs & derivatives , Rats , Urea , Uric Acid , Urine/chemistry
10.
Indian J Exp Biol ; 2003 Nov; 41(11): 1273-8
Article in English | IMSEAR | ID: sea-56032

ABSTRACT

Well known antioxidants-coumarins (7,8-dihydroxy-4-methyl coumarin-DHMC and 7,8-diacetoxy-4-methyl coumarin-DAMC) and flavonoids (quercetin-Q and quercetin penta-acetate-QPA) were investigated for their pro-oxidant effects in two human tumor cell lines. The breast carcinoma cell line (MDA-MB-468) was found to be more sensitive to treatment by the drugs-DAMC, Q and QPA at 10 microM than the glioma cell line (U-87MG), while DHMC was non toxic in both cell lines at this concentration. In MDA-MB-468 distinct growth inhibition was observed by 48 hr post treatment. Paradoxically, an increase in the formazan production was revealed by MTT assay at this time indicating an increase in the production of free radicals. An increase in the levels of reactive oxygen species (ROS) was also confirmed by DCFH-DA assay. In cells treated with DAMC, Q and QPA an increase in the percentage of cells with the hypodiploid DNA content was suggestive of apoptotic cell death. Taken together, these results suggest that an increase in oxidative stress caused by the pro-oxidant action of these drugs is responsible for cell death.


Subject(s)
Antioxidants/pharmacology , Apoptosis/drug effects , Breast Neoplasms/metabolism , Cell Cycle/drug effects , Cell Division/drug effects , Coumarins/pharmacology , Female , Glioma/metabolism , Humans , Oxidative Stress/drug effects , Ploidies , Quercetin/analogs & derivatives , Reactive Oxygen Species/metabolism , Tumor Cells, Cultured
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