Enzyme Inhibition Research Papers - Academia.edu (original) (raw)

Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of... more

Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of endophytic bacteria in growth and development of their host plants is still underestimated. However, since many endophytes have a beneficial effect on their host, an

PNU 157706 is a novel dual inhibitor of 5α-reductase (5α-R), the enzyme responsible for the conversion of testosterone (T) to 5α-dihydrotestosterone (DHT). Tested on a crude preparation of human or rat prostatic 5α-R, PNU 157706 caused... more

PNU 157706 is a novel dual inhibitor of 5α-reductase (5α-R), the enzyme responsible for the conversion of testosterone (T) to 5α-dihydrotestosterone (DHT). Tested on a crude preparation of human or rat prostatic 5α-R, PNU 157706 caused enzyme inhibition with ic50 values of 20 and 34 nM, respectively, compared to the values of 32 and 58 nM shown by finasteride. Furthermore, PNU 157706 was highly potent in inhibiting human recombinant 5α-R type I and II isozymes, showing ic50 values of 3.9 and 1.8 nM and, therefore, it was several folds more potent than finasteride (ic50 values of 313 and 11.3 nM), particularly on the type I isozyme. PNU 157706 was shown to have no binding affinity for the rat prostate androgen receptor (RBA 0.009% that of DHT). In adult male rats, a single oral dose of 10 mg/kg of PNU 157706 caused a marked and longer lasting reduction of prostatic DHT than did finasteride (at 24 h inhibition by 89 and 47%, respectively). In prepubertal, T- or DHT-implanted castrated rats, PNU 157706, given orally for 7 days at the dose of 10 mg/kg/day, markedly reduced ventral prostate weight in T- but not in DHT-implanted animals, thus showing to be devoid of any anti-androgen activity. In adult rats treated orally for 28 days, PNU 157706 resulted markedly more potent (16-fold) than finasteride in reducing prostate weight, the ed50 values being 0.12 and 1.9 mg/kg/day, respectively. These results indicate that PNU 157706 is a promising, potent inhibitor of both type II and I human 5α-R with a very marked antiprostatic effect in the rat.

The humoral and hemodynamic effects of converting enzyme inhibition captopril are presented in two patients with primary hyperaldosteronism (PHA). In all, 20 patients with resistant hypertension were treated with the angiotensin... more

The humoral and hemodynamic effects of converting enzyme inhibition captopril are presented in two patients with primary hyperaldosteronism (PHA). In all, 20 patients with resistant hypertension were treated with the angiotensin converting enzyme inhibitor captopril. In 18 patients with essential or renovascular hypertension mean (+/- SEM) plasma renin activity (PRA) rose from 5.0 +/- 1.4 to 35.3 +/- 5.3 ng/ml/hr (P less than 0.01) and mean (+/- SEM) plasma aldosterone (PA) declined from 25.8 +/- 2.9 to 15.1 +/- 1.9 ng/ml (P less than 0.01) after captopril. In two patients with PHA the PRA was not stimulated by converting enzyme inhibition, although there was modest decline in PA and a temporary reduction in blood pressure. After surgical removal of aldosterone-producing adenomas, PRA responsed appropriately to captopril. These cases illustrate that a disease process can modify the response to a drug and demonstrate that, in patients with PHA, captopril does not stimulate PRA, induc...

Journal of Applied Phycology pp 1–9 Antidiabetic and antioxidant activities of brown and red macroalgae from the Persian Gulf • Authors • Authors and affiliations • Kiana Pirian • Soheila MoeinEmail author • Jelveh Sohrabipour • Reza... more

Journal of Applied Phycology
pp 1–9
Antidiabetic and antioxidant activities of brown and red macroalgae from the Persian Gulf
• Authors
• Authors and affiliations
• Kiana Pirian
• Soheila MoeinEmail author
• Jelveh Sohrabipour
• Reza Rabiei
• Jaanika Blomster
• Kiana Pirian
o 1
• Soheila Moein
o 1
o 2
Email author
• Jelveh Sohrabipour
o 3
• Reza Rabiei
o 3
• Jaanika Blomster
o 4
1. 1.Molecular Medicine Research Center, Hormozgan Health InstituteHormozgan University of Medical ScienceBandar AbbasIran
2. 2.Department of Biochemistry, Faculty of MedicineHormozgan University of Medical SciencesBandar AbbasIran
3. 3.Department of Plant SystematicsAgriculture and Natural Resources Researches Center of HormozganBandar AbbasIran
4. 4.Department of Environmental SciencesUniversity of HelsinkiHelsinkiFinland
Article
First Online:
11 May 2017
DOI: 10.1007/s10811-017-1152-0
Cite this article as:
Pirian, K., Moein, S., Sohrabipour, J. et al. J Appl Phycol (2017). doi:10.1007/s10811-017-1152-0
• 1 Shares
Abstract
The inhibition of pancreatic α-amylase and the prevention of pancreatic oxidative damage are considered possible strategies for the management of type 2 diabetes. The aim of our study was to evaluate in vitro the antioxidant properties and α-amylase inhibition of ten brown and red macroalgal species from the Persian Gulf. The α-amylase inhibition was tested using the chromogenic dinitrosalicylic acid (DNS) method, and the antioxidant properties were evaluated using the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging and ferric reducing antioxidant power (FRAP) methods. The results of our study showed that all analyzed macroalgal species revealed antioxidant effects and α-amylase inhibitory activities. Among the studied species, the highest α-amylase inhibition was shown by the brown algae Sirophysalis trinodis (IC50 0.42 mg mL−1, 32–97% inhibition), Polycladia myrica (IC50 = 0.72 mg mL−1, 32–97% inhibition), and the red alga Palisada perforata (IC50 = 1.1 mg mL−1, 27–91%). Sirophysalis trinodis (125.4 μg ASA mg−1) and Sargassum angustifolium (IC50 = 0.40 mg mL−1) had the highest FRAP-reducing power and ABTS radical scavenging activities, respectively. In addition to the species, α-amylase inhibition and the antioxidant effects depended on the type of solvent used for algal extraction; the best properties were generally presented by methanol and ethyl acetate. In conclusion, the enzyme inhibition and antioxidant activities of S. trinodis, P. myrica, P. perforata, and S. angustifolium suggest that they may have potential for antidiabetic and antioxidant use and could therefore be studied further for potential pharmaceutical use.
Keywords
α-amylase inhibition ABTS radical scavenging Diabetes mellitus FRAP method Macroalgae Persian Gulf

Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with... more

Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with postcolumn derivatization and fluorometric detection. About 200 clinical plasma samples from 13 children with acute lymphoblastic leukemia who received 5-8 g/m2 MTX as 24-h infusions were analyzed. The fraction of measured concentrations of MTX that were within 75-125% of the values obtained by HPLC were 64.5% for enzyme inhibition assay, 56.4% for fluorescence polarization immunoassay with polyclonal antibodies (FPIA1; Abbott), 58.9% for FPIA2 (with monoclonal antibodies; Abbott), and 46.4% for enzyme-multiplied immunoassay (Emit; Syva). All nonchromatographic procedures were subject to interferences from MTX plasma metabolites or endogenous substances. The interference from 7-OHMTX was, however, somewhat less pronounced for FPIA2 (monoclonal) than...

1. Gliotoxin belongs to the epipolythiodioxopiperazine class of secondary metabolites. These compounds show a diverse range of biological activity including antimicrobial, antifungal and antiviral properties. They also display potent in... more

1. Gliotoxin belongs to the epipolythiodioxopiperazine class of secondary metabolites. These compounds show a diverse range of biological activity including antimicrobial, antifungal and antiviral properties. They also display potent in vitro and in vivo immunomodulating activity. 2. Their properties resulted in a number of early studies designed to exploit their possible chemotherapeutic value, although the general toxicity of most members of this class has precluded clinical use. 3. Most recently, their selective immunosuppressive properties have led to the possibility of ex vivo treatment of tissue to selectively remove immune cells responsible for tissue rejection. The mode of action of gliotoxin appears to be via covalent interaction to proteins through mixed disulphide formation and gliotoxin has been shown to inhibit a number of thiol requiring enzymes. 4. Gliotoxin is also a potent inducer of apoptotic cell death in a number of cells. Gliotoxin and other members of this clas...