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Metabolic enzyme inhibitory abilities, in vivo hypoglycemic ability of palmleaf raspberry fruits extracts and identification of hypoglycemic compounds

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Food Science and Human Wellness 2023年第4期12卷 1232-1240页

作者： Jun Tan Danshu Wang Yu Lu Yehan Wang Zongcai Tu Tao Yuan Lu Zhang National R&D Center for Freshwater Fish Processing Engineering Research Center of Freshwater Fish High-Value Utilization of Jiangxi ProvinceCollege of Life ScienceJiangxi Normal UniversityNanchangJiangxi 330022China

The unripe palmleaf raspberry,namely Fupenzi(FPZ),is an important medicinal and edible *** study aims to evaluate the potential of FPZ extracts prepared with different approaches in attenuating hyperglycemia,gout,Alzheimer’s disease,and pigmentation,to obtain the enriching fraction and to identify the major active *** indicated that FPZ extracts showed weak activity against acetylcholinesterase,considerable ability against tyrosinase and xanthine oxidase,but excellent inhibition onα-***-assisted 40%ethanol extract(40EUS)gave the highest phenolics content,and the bestα-glucosidase inhibition(IC_(50)=0.08μg/mL),which is 877-fold higher than that of positive control *** 40%ethanol eluting fraction of 40EUS showed the strongestα-glucosidase inhibition with the IC_(50) value of 37.79 ng/mL,it could also effectively attenuate the fasting blood glucose level and oral glucose tolerance of C57BL/6 ***-six compounds were identified from 40%ethanol fraction by using HPLC-QTOF-MS/MS,hydrolysable tannins(including 11 ellagitannins and 4 gallotannins)were the major compounds,phenolic acids came to the *** results could provide important technical supporting for the further application and research of FPZ in health foods and drugs against diabetes.

关键词： Pal mleaf raspberry Extraction and identification enzyme inhibition HPLC-QTOF-MS/MS Hypoglycemic activity

Broken electron transfer pathway in enzyme:Gold clusters inhibiting TrxR1/Trx via cell studies and theory simulations

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Chinese Chemical Letters 2022年第7期33卷 3488-3491页

作者： Wenchao Niu Zhongying Du Chunyu Zhang Deting Xu Jiaojiao Li Minghui Sun Liyuan Wu Haodong Yao Lina Zhao Xueyun Gao Department of Chemistry and Biology Beijing University of TechnologyBeijing 100124China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

Thioredoxin reductase 1(TrxR1)is over activity in tumor cell to maintain their redox *** gold clusters have great potential in antitumor drug as they could well inhibit TrxR1,the molecular mechanism has not been disclosed *** this work,we revealed gold clusters can well inhibit the activity of TrxR1 in lung tumor cells and further disclosed the inhibition mechanism by using computational simulation *** firstly inferred the binding sites of gold in the hydrophobic cavities on *** simulation results show that the gold ion(released from Au cluster)interact with–SH of Cys189 in TrxR1,this greatly increase the distance between the C-terminal redox center of TrxR1 and the Trx redox center,thereby destroy the electron transfer pathway between *** electron transfer destroying mechanism is different from the previous hypothesis that gold binds to the Sec498 of TrxR1 which has never been proved by experimental and theory *** work provides a new understanding of the gold clusters to inhibit TrxR1 activity.

关键词： enzyme inhibition Electron transfer Thioredoxin reductase 1 Gold clusters Molecular dynamics Density functional theory

Rhus longipes (Engl.) infusions improve glucose metabolism and mitigate oxidative biomarkers in ferrous sulfate-induced renal injury

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Asian Pacific Journal of Tropical Biomedicine 2022年第11期12卷 453-465页

作者： Brian K.Beseni Kolawole AOlofinsan Veronica F.Salau Ochuko L.Erukainure Md.Shahidul Islam Department of Biochemistry University of KwaZulu-NatalWestville CampusDurban 4000South Africa Department of Pharmacology University of the Free StateBloemfontein 9300South Africa

Objective:To explore the antioxidant and antidiabetic activities of Rhus longipes(***)leaf and stem bark aqueous ***:*** leaf and stem bark infusions were characterized via gas-chromatography mass-spectroscopy(GC-MS)*** vitro antioxidant and carbohydrate and lipid digestive enzyme inhibitory activities of *** infusions were ***,the modulatory effects of *** infusions on intestinal glucose absorption,muscle glucose uptake,and biomarkers of renal oxidative injury were *** docking was performed to determine the binding affinities of the identified compounds from the leaf and stem bark infusions on carbohydrate and lipid digestive ***:GC-MS analysis revealed the presence of several phytocompounds,including palmitoleic acid,octadecanamide,24,25-dihydroxyvitamin D and L-ascorbic *** bark infusion had significantly higher total phenolic contents compared with the leaf infusion,with better DPPH scavenging[IC_(50):(10.50±1.03)μg/mL]and ferric reducing[IC_(50):(9.85±0.32)μg/mL]activities(P<0.05).Both *** infusions at their highest concentrations significantly increased glucose uptake in yeast suspension and rat psoas muscle with marked suppression of glucose absorption in the rat jejunum(P<0.05).With no cytotoxicity on Vero cells,the infusions lowered lipid peroxidation,increased cellular reduced glutathione concentration,and the activities of superoxide dismutase and catalase in renal homogenate treated with FeSO_(4).Conclusions:*** shows antioxidant and antidiabetic activities and could be a potential therapeutic candidate for diabetes.

关键词： Antioxidant Oxidative biomarkers enzyme inhibition Antidiabetic Rhus longipes Searsia longipes

Biochemical characterization of chitin synthase activity and inhibition in the African malaria mosquito, Anopheles gambiae

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Insect Science 2013年第2期20卷 158-166页

作者： Xin Zhang Kun Yan Zhu Department of Entomology Kansas State University Manhattan KS 66506 USA

Chitin synthase （CHS） is an important enzyme catalyzing the formation of chitin polymers in all chitin containing organisms and a potential target site for insect pest control. However, our understanding of biochemical properties of insect CHSs has been very limited. We here report enzymatic and inhibitory properties of CHS prepared from the African malaria mosquito, Anopheles gambiae. Our study, which represents the first time to use a nonradioactive method to assay CHS activity in an insect species, determined the optimal conditions for measuring the enzyme activity, including pH, temperature, and concentrations of the substrate uridine diphosphate N-acetyl-D-glucosamine （UDP- GlcNAc） and Mg＋＋. The optimal pH was about 6.5-7.0, and the highest activity was detected at temperatures between 37℃ and 44℃. Dithithreitol is required to prevent melanization of the enzyme extract. CHS activity was enhanced at low concentration of GIcNAc, but inhibited at high concentrations. Proteolytic activation of the activity is significant both in the 500×g supernatant and the 40 000×g pellet. Our study revealed only slight in vitro inhibition ofA. gambiae CHS activity by diflubenzuron and nikkomycin Z at the highest concentration （2.5μmol/L） examined. There was no in vitro inhibition by polyoxin D at any concentration examined. Furthermore, we did not observe any in vivo inhibition of CHS activity by any of these chemicals at any concentration examined. Our results suggest that the inhibition of chitin synthesis by these chemicals is not due to direct inhibition of CHS in A. gambiae.

关键词： Anophele gambiae chitin synthase diflubenzuron enzyme inhibition

Effects of genistein and equol on human and rat testicular 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase 3 activities

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Asian Journal of Andrology 2010年第4期12卷 519-526页

作者： Guo-Xin Hu Bing-Hai Zhao Yan-Hui Chu Hong-Yu Zhou Benson T. Akingbemi Zhi-Qiang Zheng Ren-Shan Ge Population Council New York NY 10065 USA School of Pharmacy Wenzhou Medical College Wenzhou 325000 China Heilongjiang Key Laboratory of Anti-fibrosis Biotherapy Mudanjiang Medical University Mudanjiang 157001 China Departments of Anatomy Physiology and Pharmacology Auburn University Auburn AL 36849 USA The Second Affiliated Hospital Wenzhou Medical College Wenzhou 325000 China

The objective of the present study was to investigate the effects of genistein and equol on 3β-hydroxysteroid de- hydrogenase （3β-HSD） and 17β-hydroxysteroid dehydrogenase 3 （17β-HSD3） in human and rat testis microsomes. These enzymes （3β-HSD and 17β-HSD3）, along with two others （cytochrome P450 side-chain cleavage enzyme and cytochrome P450 17α-hydroxylase/17-20 lyase）, catalyze the reactions that convert the steroid cholesterol into the sex hormone testosterone. Genistein inhibited 3β-HSD activity （0.2 μmol L^-1 pregnenolone） with half-maximal inhibition or a half-maximal inhibitory concentration （IC50） of 87 ± 15 （human） and 636 ± 155 nmol L^-1 （rat）. Genistein＇s mode of action on 3β-HSD activity was competitive for the substrate pregnenolonrge and noncompetitive for the cofactor NAD＋. There was no difference in genistein＇s potency of 3β-HSD inhibition between intact rat Leydig cells and testis microsomes. In contrast to its potent inhibition of 3β-HSD, genistein had lesser effects on human and rat 17β-HSD3 （0.1 μmol L^-1 androstenedione）, with an IC50 〉 100μmol L^-1. On the other hand, equol only inhibited human 3β-HSD by 42%, and had no effect on 3β-HSD and 17β-HSD3 in rat tissues. These observations imply that the ability of soy isoflavones to regulate androgen biosynthesis in Leydig cells is due in part to action on Leydig cell 3β- HSD activity. Given the increasing intake of soy-based food products and their potential effect on blood androgen levels, these findings are greatly relevant to public health.

关键词： 3β-hydroxysteroid dehydrogenase 17β-hydroxysteroid dehydrogenase 3 enzyme inhibition equol genistein

Assembly of IMPDH2-Based,CTPS-Based,and Mixed Rod/Ring Structures Is Dependent on Cell Type and Conditions of Induction

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Journal of Genetics and Genomics 2015年第6期42卷 287-299页

作者： Gerson Dierley Keppeke S.John Calise Edward K.L.Chan Luis Eduardo C.Andrade Rheumatology Division Federal University of Sao Paulo Department of Oral Biology University of Florida Immunology Division Fleury Medicine and Health Laboratories

inhibition of guanosine triphosphate（GTP） and cytidine triphosphate（CTP） biosynthetic pathways induces cells to assemble rod/ring（RR） structures,also named cytoophidia,which consist of the enzymes cytidine triphosphate synthase（CTPS） and inosine-50-monophosphate dehydrogenase 2（IMPDH2）.We aim to explore the interaction of CTPS and IMPDH2 in the generation of RR *** La and COS-7 cells were cultured in normal conditions or in the presence of 6-diazo-5-oxo-L-norleucine（DON）,ribavirin,or mycophenolic acid（MPA）.Over 90% of DON-treated cells presented RR *** He La cells,35% of the RR structures were positive for IMPDH2 alone,26% were CTPS alone,and 31% were IMPDH2/CTPS mixed,while in COS-7 cells,42% of RR were IMPDH2 alone,41% were CTPS alone,and 10% were IMPDH2/CTPS *** and MPA treatments induced only IMPDH2-based *** were also transfected with an N-terminal hemagglutinin（NHA）-tagged CTPS1 *** 95% of NHA-CTPS1 transfected cells with DON treatment presented IMPDH2-based RR and almost 100% presented CTPS1-based RR;when treated with ribavirin,over 94% of transfected cells presented IMPDH2-based RR and 37% presented CTPS1-based RR,whereas 2% of untreated transfected cells presented IMPDH2-based RR and 28% presented CTPS1-based *** results may help in understanding the relationship between CTP and GTP biosynthetic pathways,especially concerning the formation of filamentous RR structures.

关键词： Nucleotide synthesis enzyme aggregation enzyme inhibition IMPDH2 CTPS

Novel semicarbazide-sensitive amine oxidase inhibitor screening from anti-obesity drugs using HPLC-MS based technique

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Journal of Beijing Institute of Technology 2013年第1期22卷 135-142页

作者：车宝泉王琳张永谦肖盛元邓玉林 School of Life Science Beijing Institute of Technology Beijing Institute for Drug Control

Semicarbazide-sensitive the metabolism of glucose and fat, amine oxidase （SSAO） has been considered to be associated with and elevated SSAO activity was observed in obese patients. In the present study, an in vitro SSAO activity-based method was developed to screen inhibitors from 15 an- ti-obesity drugs. Among the fifteen anti-obesity drugs, four drugs including caffeine, fenfluramine, bumetanide and amfebutamone inhibited SSAO activity, and caffeine was the most effective one. When the concentration of caffeine was 1.4 mmol/L, the inhibition ratio was 31.9% and 18.8% in rabbit serum and rat adipose tissue, respectively. inhibition of SSAO activity by caffeine was also confirmed in the in vivo study, showing the inhibition ratio of 15.6% on serum SSAO. Caffeine pro- vides a natural source of inhibition of SSAO activity and may be a promising inhibitor for the study of SSAO.

关键词： anti-obesity drugs caffeine enzyme inhibition HPLC-MS semicarbazide-sensitive a-mine oxidase

Characterization of Carboxylesterase Associated with Malathion Insensitivity in the Field Population of the Oriental Migratory Locust

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Agricultural Sciences in China 2008年第5期7卷 591-598页

作者： YANG Mei-ling ZHANG Jian-zhen ZHANG Jian-qin GUO Ya-ping MA En-bo Institute of Applied Biology Shanxi University Taiyuan 030006 P.R. China

Carboxylesterases （CarEs） from two field populations of the oriental migratory locust, Locusta migratoria manilensis （Meyen）, were examined to try to understand their contribution to malathion insensitivity. The CarEs activities in Wudi population （WD） were 1.75- and 1.50-fold significantly higher than those in Huangliu population （HL） when a-naphthyl acetate （a-NA） and [3-naphthyl acetate were used as substrates, respectively. Such elevated CarEs activities presented in the WD could be because of an increased staining intensity of the a-NA-hydrolyzing CarEs as shown on the nondenaturing polyacrylamide gel electrophoresis. inhibition studies of CarEs using paraoxon and malaoxon indicated that CarE activities in the HL were more strongly inhibited than those in the WD. Furthermore, a 449-bp DNA fragment of CarE was obtained from L. migratoria manilensis. Hemiquantity reverse transcription-polymerase chain reaction analysis showed that CarE gene expression level in the WD was higher than that in the HL. The higher CarE activities and the increased CarE mRNA level in the WD appeared to be associated with decreased susceptibility to malathion in the WD due to the application of organophosphorus insecticides.

关键词： carboxylesterases enzyme kinetics enzyme inhibition RT-PCR Locusta migratoria manilensis

Methanol extracts of Brachystegia eurycoma and Detarium microcarpum seeds flours inhibit some key enzymes linked to the pathology and complications of type 2 diabetes in vitro

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Food Science and Human Wellness 2015年第4期4卷 162-168页

作者： Emmanuel Anyachukwu Irondi Ganiyu Oboh Afolabi Akintunde Akindahunsi Department of Biochemistry Federal University of TechnologyAkureP.M.B.704Akure 340001Nigeria Biochemistry Unit Department of Biosciences and BiotechnologyKwara State UniversityMaleteP.M.B.1530IlorinNigeria

The inhibitory effect of methanol extracts of Brachystegia eurycoma and Detarium microcarpum seeds flours on some key enzymes[α-amylase,α-glucosidase and aldose reductase(AR)]linked to the pathology and complications of type 2 diabetes(T2D);and their antioxidant properties were *** antioxidant properties evaluated were DPPH•and ABTS•^+scavenging abilities,reducing power,and antioxidant phytochemicals(total phenolics,tannins,total flavonoids and total saponins).Extracts of both flours inhibitedα-amylase,α-glucosidase and AR in a dose-dependent *** half-maximal inhibitory concentrations(IC50)of *** onα-amylase,α-glucosidase,AR and lipid peroxidation were lower than those of ***,indicating that it had stronger inhibitory potency than *** also had significantly(P<0.05)higher DPPH•and ABTS•^+scavenging abilities,and reducing power than *** antioxidant phytochemicals(total phenolics,tannins,total flavonoids and total saponins)were also significantly(P<0.05)higher in *** than *** inhibitory effect of *** and *** extracts onα-amylase,α-glucosidase and AR activities may be attributed to the combined action of their polyphenols and total saponins,and this may be a possible mechanism of action providing support for their use in managing hyperglycemia and the complications of T2D.

关键词： Type 2 diabetes enzyme inhibition Antioxidants Phytochemical Brachystegia eurycoma Detarium microcarpum