New α-Glucosidase Inhibitory Triterpenic Acid from Marine Macro Green Alga Codium dwarkense Boergs     

Liaqat Ali  Abdul Latif Khan  Lubna Al-Kharusi  Javid Hussain  Ahmed Al-Harrasi 《Marine drugs》2015,13(7):4344-4356

The marine ecosystem has been a key resource for secondary metabolites with promising biological roles. In the current study, bioassay-guided phytochemical investigations were carried out to assess the presence of enzyme inhibitory chemical constituents from the methanolic extract of marine green alga—Codium dwarkense. The bioactive fractions were further subjected to chromatographic separations, which resulted in the isolation of a new triterpenic acid; dwarkenoic acid (1) and the known sterols; androst-5-en-3β-ol (2), stigmasta-5,25-dien-3β,7α-diol (3), ergosta-5,25-dien-3β-ol (4), 7-hydroxystigmasta-4,25-dien-3-one-7-O-β-d-fucopyranoside (5), 7-hydroxystigmasta-4,25-dien-3-one (6), and stigmasta-5,25-dien-3β-ol (7). The structure elucidation of the new compound was carried out by combined mass spectrometry and 1D (¹H and ¹³C) and 2D (HSQC, HMBC, COSY, and NOESY) NMR spectroscopic data. The sub-fractions and pure constituents were assayed for enzymatic inhibition of alpha-glucosidase. Compound 1 showed significant inhibition at all concentrations. Compounds 2, 3, 5, and 7 exhibited a dose-dependent response, whereas compounds 4–6 showed moderate inhibition. Utilizing such marine-derived biological resources could lead to drug discoveries related to anti-diabetics.  相似文献   

Araguspongine C Induces Autophagic Death in Breast Cancer Cells through Suppression of c-Met and HER2 Receptor Tyrosine Kinase Signaling     

Mohamed R. Akl  Nehad M. Ayoub  Hassan Y. Ebrahim  Mohamed M. Mohyeldin  Khaled Y. Orabi  Ahmed I. Foudah  Khalid A. El Sayed 《Marine drugs》2015,13(1):288-311

Receptor tyrosine kinases are key regulators of cellular growth and proliferation. Dysregulations of receptor tyrosine kinases in cancer cells may promote tumorigenesis by multiple mechanisms including enhanced cell survival and inhibition of cell death. Araguspongines represent a group of macrocyclic oxaquinolizidine alkaloids isolated from the marine sponge Xestospongia species. This study evaluated the anticancer activity of the known oxaquinolizidine alkaloids araguspongines A, C, K and L, and xestospongin B against breast cancer cells. Araguspongine C inhibited the proliferation of multiple breast cancer cell lines in vitro in a dose-dependent manner. Interestingly, araguspongine C-induced autophagic cell death in HER2-overexpressing BT-474 breast cancer cells was characterized by vacuole formation and upregulation of autophagy markers including LC3A/B, Atg3, Atg7, and Atg16L. Araguspongine C-induced autophagy was associated with suppression of c-Met and HER2 receptor tyrosine kinase activation. Further in-silico docking studies and cell-free Z-LYTE assays indicated the potential of direct interaction between araguspongine C and the receptor tyrosine kinases c-Met and HER2 at their kinase domains. Remarkably, araguspongine C treatment resulted in the suppression of PI3K/Akt/mTOR signaling cascade in breast cancer cells undergoing autophagy. Induction of autophagic death in BT-474 cells was also associated with decreased levels of inositol 1,4,5-trisphosphate receptor upon treatment with effective concentration of araguspongine C. In conclusion, results of this study are the first to reveal the potential of araguspongine C as an inhibitor to receptor tyrosine kinases resulting in the induction of autophagic cell death in breast cancer cells.  相似文献   

Structure Elucidation and in Vitro Toxicity of New Azaspiracids Isolated from the Marine Dinoflagellate Azadinium poporum     

Bernd Krock  Urban Tillmann  éric Potvin  Hae Jin Jeong  Wolfgang Drebing  Jane Kilcoyne  Ahmed Al-Jorani  Michael J. Twiner  Qun G?thel  Matthias K?ck 《Marine drugs》2015,13(11):6687-6702

Two strains of Azadinium poporum, one from the Korean West coast and the other from the North Sea, were mass cultured for isolation of new azaspiracids. Approximately 0.9 mg of pure AZA-36 (1) and 1.3 mg of pure AZA-37 (2) were isolated from the Korean (870 L) and North Sea (120 L) strains, respectively. The structures were determined to be 3-hydroxy-8-methyl-39-demethyl-azaspiracid-1 (1) and 3-hydroxy-7,8-dihydro-39-demethyl-azaspiracid-1 (2) by ¹H- and ¹³C-NMR. Using the Jurkat T lymphocyte cell toxicity assay, (1) and (2) were found to be 6- and 3-fold less toxic than AZA-1, respectively.  相似文献   

Insecticidal potency of RNAi‐based catalase knockdown in Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae)          下载免费PDF全文

Abid Hussain  Ahmed M Aljabr 《Pest management science》2016,72(11):2118-2127

  相似文献   

Establishing a high throughput screening method for large scale phenotyping of castor genotypes for resistance to <Emphasis Type="Italic">Fusarium</Emphasis> wilt disease     

Ranjan K. Shaw  Mobeen Shaik  Zubair Ahmed Mir  M. Santha Lakshmi Prasad  R. D. Prasad  S. Senthilvel 《Phytoparasitica》2016,44(4):539-548

  相似文献   

Marketing systems of freshwater prawns in three coastal districts of Bangladesh     

Md. Kawser Ahmed  Shamima Sultana  Sadeka Halim  Md. Monirul Islam 《Aquaculture Economics & Management (Blackwell Science)》2016,20(3):272-282

The present study analyzes the prawn marketing chain before and after the implementation of a Danish-funded project (GNAEP) in three coastal districts of greater Noakhali, southeast region of Bangladesh. The results reveal that, before GNAEP, there was a longer prawn marketing chain with a number of intermediaries who used to share a considerable amount of market margin. However, after implementation of GNAEP, the prawn marketing chain has become shorter with a significant reduction of intermediaries which facilitates direct selling of prawns to processing plants through local Community Based Organizations (CBOs). The present prawn marketing system in the regions is in favor of prawn farmers. Farmers have greater advantages because 1) CBOs provide reasonable market price and actual weight, 2) CBOs can bargain with processing plants as the former are aware of the latest international market prices through Marketing Information System 3) number of intermediaries is lowered and 4) transport and preservation costs are reduced. The displaced intermediaries, some of whom are powerful persons in the society, have again started to influence the prawn market in different ways. This fact has opened up another discussion on how the power structure is shifting in this region and how they are affecting prawn marketing.  相似文献   

Characteristics of prolactin-releasing response to salsolinol in vivo in cattle     

T. Hashizume  T. Sawada  T. Yaegashi  H. Saito  A. Ezzat Ahmed  Y. Goto  Y. Nakajima  J. Jin  E. Kasuya  G.M. Nagy 《Domestic animal endocrinology》2010

The aims of the present study were to clarify the effect of salsolinol (SAL), a dopamine (DA)-derived endogenous compound, on the secretion of prolactin (PRL) in cattle. The experiments were performed from April to June using calves and cows. A single intravenous (i.v.) injection of SAL (5 mg/kg body weight [BW]) or sulpiride (a DA receptor antagonist, 0.1 mg/kg BW) significantly stimulated the release of PRL in male and female calves (P < 0.05), though the response to SAL was smaller than that to sulpiride. The secretory pattern of PRL in response to SAL or sulpiride in female calves resembled that in male calves. A single i.v. injection of SAL or sulpiride significantly stimulated the release of PRL in cows (P < 0.05). There was no significant difference in the PRL-releasing response between the SAL- and sulpiride-injected groups in cows. A single intracerebroventricular injection of SAL (10 mg/head) also significantly stimulated the release of PRL in castrated calves (P < 0.05). These results show that SAL is involved in the regulatory process for the secretion of PRL, not only in male and female calves, but also in cows. The results also suggest that the potency of the PRL-releasing response to SAL differs with the physiological status of cattle.  相似文献   

Response to partial replacement of yellow corn with potato processing waste as non-traditional source of energy on the productive performance of Ossimi lambs     

Hamed A. A. Omer  Soha S. Abdel-Magid  Sawsan M. Ahmed  Mamdouh I. Mohamed  I. M. Awadalla 《Tropical animal health and production》2010,42(6):1195-1202

Twenty-one male growing lambs aged 6 months with an average weight 27.6 ± 0.24 kg were used to determine the effects of partial replacing yellow corn with potato processing waste (PPW) on performance of Ossimi lambs. Animals divided into three equal groups and assigned for control and two experimental diets containing PPW which was replaced from yellow corn at 0% PPW (R₁), 25% PPW (R₂), and 50% PPW (R₃). The results showed that tested rations were almost isocaloric and isonitrogenous. Dietary treatments had no significant effect on feed intake, while water intake insignificantly decreased. Digestibility coefficients of dry matter, organic matter, and crude protein significantly (P < 0.05) improved. However, dietary treatment had no significant effect on crude fiber and nitrogen-free extract digestibilities. Values of total digestible nutrient and digestible crude protein significantly (P < 0.05) increased. Nitrogen retention was positive for all groups. Dietary treatments had no significant effect on ruminal pH but insignificantly decreased ammonia nitrogen (NH₃–N) concentrations. However, total volatile fatty acid concentration was increased. Dietary treatments increased molar proportion of volatile fatty acids. Final weight, body weight gain, and average daily gain were significantly (P < 0.05) decreased, while feed conversion ratio insignificantly decreased. Inclusion of PPW decreased total daily feeding costs of experimental rations. PPW could be used as a source of energy in lamb rations instead of corn grain. Also, PPW can be successfully fed to lamb without any adverse effect on their performance, and it can be an economical substitute for grain.  相似文献   

Effect of Needle Size and Type,Reuse of Needles,Insertion Speed,and Removal of Hair on Contamination of Joints with Tissue Debris and Hair after Arthrocentesis     

Stephen B. Adams DVM  MS  Diplomate ACVS  George E. Moore DVM  PhD  Diplomate ACVIM & ACVPM  Mohammed Elrashidy BVSc  MSc  Ahmed Mohamed BVSc  MSc  Paul W. Snyder DVM  PhD  Diplomate ACVP 《Veterinary surgery : VS》2010,39(6):667-673

  相似文献   

Characterization of Embryonic Stages through Variations in the Egg＇s Contents in Spodoptera fitura     

F. Perveen  H. Ahmed  F. M. Abbasi  N. Y. Siddiqui  A. Gul 《农业科学与技术》2010,(5):24-36

This paper describes the embryonic development of the common cutworm Spodoptera litura （Fabricius） （Lepidoptera： Noctuidae） which is divided into eight embryonic stages, through variations in the egg＇s contents. Experiments were conducted on the eggs ofS. litura under laboratory conditions. The highest concentration of the protein （min.-max.： 32-! 40 lag/egg） and the lowest of the carbohydrate （min.-max.： 3.0-44.0 lag/egg） were obtained; similarly, the DNA content was smaller （min.-max.： 1.0-38.2 lag/egg） than the RNA （min.-max.： 9.2-360.0 lag/egg） throughout the embryogenesis. Three peaks of ecdysteroid titre were observed which were responsible for appearance of particular events during embryogenesis. The last highest peak of 400_＋33.4 lag/egg was appeared at 84 h after oviposition when larva was ready to hatch. Therefore, it is concluded that eight embryonic stages in S. litura were characterized by fluctuation in the egg＇s contents, which were responsible for gradual-progressive embryonic development. The egg-larval development did not show a normal distribution of embryonic developmental-time.  相似文献