scholarly journals Insulin Release from NPH Insulin-Loaded Pluronic® F127 Hydrogel in the Presence of Simulated Tissue Enzyme Activity

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1320
Author(s):  
Muhammad H. Sultan ◽  
Wael A. Mahdi ◽  
Young M. Kwon
Keyword(s):  
Enzyme Activity ◽  
Insulin Release ◽  
Burst Release ◽  
Nph Insulin ◽  
Native Form ◽  
Gelling Temperature ◽  
History Of ◽  
History Of Use ◽  
In Vitro Insulin Release

Background: Despite the widespread use of newer basal insulins, Natural Protamine Hagedorn (NPH) insulin still represents a well-established basal formulation with its long history of use, featuring the native form of human insulin. However, NPH insulin exhibits an undesirable peak within hours after a single subcutaneous (s.c.) injection, which may lead to hypoglycemia followed by insufficient basal insulin delivery. This may be attributed to the s.c. enzyme activities degrading the protamine in NPH microcrystals. Methods: A thermogelling block copolymer Pluronic® F127 (PF127) was utilized as a protective carrier for NPH microcrystals and as a modulator for insulin release from NPH. NPH insulin-loaded PF127 gel was prepared with varying concentrations of the polymer (15–25%) under mild conditions. The formulations were characterized for their gelling temperature, morphology, gel erosion, and in vitro insulin release, with trypsin concentrations up to 5 U/mL. Results: Scanning electron microscopy (SEM) showed that the integrity of NPH microcrystals was maintained after preparation. The burst release of insulin from NPH was significantly attenuated over the course of ~16h in the presence of PF127 with or without enzyme activity. Conclusion: NPH-PF127 successfully resisted the acceleration of NPH crystal dissolution and insulin release in vitro in the presence of protamine-degrading enzyme activity, warranting further testing.

scholarly journals Mechanism of inhibition of cytochrome P450 C21 enzyme activity by autoantibodies from patients with Addison’s disease

2005 ◽  
Vol 152 (1) ◽  
pp. 95-101 ◽  
Author(s):  
L Nikfarjam ◽  
S Kominami ◽  
T Yamazaki ◽  
S Chen ◽  
R Hewer ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Enzyme Activity ◽  
Cytochrome P450 ◽  
Conformational Changes ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Cytochrome P450 Reductase ◽  
Difference Spectra ◽  
Native Form ◽  
Mechanism Of Inhibition

Objective: To study possible mechanisms for the inhibition of cytochrome P450 C21 (steroid 21-hydroxylase) enzyme activity by P450 C21 autoantibodies (Abs) in vitro. Design: Two possible mechanisms for the inhibition of P450 C21 enzyme activity by P450 C21 Abs were studied: (a) conformational changes in the P450 C21 molecule induced by Ab binding and (b) the effects of Ab binding to P450 C21 on the electron transfer from the nicotinamide adenine dinucleotide phosphate reduced (NADPH) cytochrome P450 reductase (CPR) to P450 C21. Methods: The effect of P450 C21 Ab binding on the conformation of recombinant P450 C21 in yeast microsomes was studied using an analysis of the dithionite-reduced CO difference spectra. The effect of P450 C21 Abs on electron transfer was assessed by analysis of reduction of P450 C21 in the microsomes in the presence of CO after addition of NADPH. Results: Our studies confirmed the inhibiting effect of P450 C21 Abs on P450 C21 enzyme activity. Binding of the Abs did not induce significant change in the P450 C21 peak at 450 nm (native form) and did not produce a detectable peak at 420 nm (denatured form) in the dithionite-reduced CO difference spectra. This indicated that conformation of P450 C21 around the heme was not altered compared with the native structure. However, incubation of the P450 C21 in yeast microsomes with P450 C21 Ab inhibited the fast phase electron transfer from the CPR to P450 C21. Conclusions: Our observations suggested that the mechanism by which P450 C21 Abs inhibit P450 C21 enzyme activity most likely involves inhibition of the interaction between the CPR and P450 C21.

pH Responsive Polymeric Nanoparticles for Oral Insulin Delivery

2017 ◽  
pp. 6-10
Author(s):  
Charu Tyagi
Keyword(s):  
Insulin Release ◽  
Polymeric Nanoparticles ◽  
Attenuated Total Reflectance ◽  
Ph Responsive ◽  
Eudragit L100 ◽  
Release Studies ◽  
Mean Size ◽  
The Mean ◽  
In Vitro Insulin Release

Gelatin-eudragit L100 nanoparticles of wet size range 170-563nm were prepared by two step dissolvation method and the effect of different concentrations of eudragit L100 and emulsifying agent - sodium lauryl sulphate (SLS) - on the particle size were studied. Synthesized nanoparticles were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATRFTIR) and the mean size distribution. Insulin loading was done at a pH 7.4 and the in vitro insulin release studies of nanoparticles were carried out by simulating gastrointestinal tract condition which showed the minimal insulin release at pH 2.5 (20% in 90min) while appreciable release (40% in first 30min) at pH of 7.4. This pH responsive release pattern of the synthesized nanoparticles confers on the insulin protection from proteolytic degradation in acidic environment of stomach and upper intestinal part while enhancing bioavailability in the later part of intestine.

Regulation of in Vitro Insulin Release from a Transplantable Syrian Hamster Insulinoma1

Endocrinology ◽  
1975 ◽  
Vol 97 (2) ◽  
pp. 442-447 ◽  
Author(s):  
SHELLEY SHAPIRO ◽  
SUMIYA ETO ◽  
NORMAN FLEISCHER ◽  
STEPHEN G. BAUM
Keyword(s):  
Insulin Release ◽  
Syrian Hamster ◽  
In Vitro Insulin Release

scholarly journals Traditional Chinese Medicine for Senile Dementia

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Zhihong Lin ◽  
Jie Gu ◽  
Jin Xiu ◽  
Tingyan Mi ◽  
Jie Dong ◽  
...  
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Senile Dementia ◽  
Scientific Evidence ◽  
Sinapic Acid ◽  
Frequency Of Use ◽  
History Of ◽  
History Of Use

Traditional Chinese Medicine (TCM) has a 3000 years' history of human use. A literature survey addressing traditional evidence from human studies was done, with key result that top 10 TCM herb ingredients includingPoria cocos,Radix polygalae,Radix glycyrrhizae,Radix angelica sinensis, andRadix rehmanniaewere prioritized for highest potential benefit to dementia intervention, related to the highest frequency of use in 236 formulae collected from 29 ancient Pharmacopoeias, ancient formula books, or historical archives on ancient renowned TCM doctors, over the past 10 centuries. Based on the history of use, there was strong clinical support thatRadix polygalaeis memory improving. Pharmacological investigation also indicated that all the five ingredients mentioned above can elicit memory-improving effectsin vivoandin vitrovia multiple mechanisms of action, covering estrogen-like, cholinergic, antioxidant, anti-inflammatory, antiapoptotic, neurogenetic, and anti-Aβ activities. Furthermore, 11 active principles were identified, including sinapic acid, tenuifolin, isoliquiritigenin, liquiritigenin, glabridin, ferulic acid, Z-ligustilide, N-methyl-beta-carboline-3-carboxamide, coniferyl ferulate and 11-angeloylsenkyunolide F, and catalpol. It can be concluded that TCM has a potential for complementary and alternative role in treating senile dementia. The scientific evidence is being continuously mined to back up the traditional medical wisdom.

The In Vitro and In Vivo Genotoxicity of Benzocaine: A Brief Communication

2012 ◽  
Vol 31 (3) ◽  
pp. 222-227 ◽  
Author(s):  
William J. Brock ◽  
Thomas A. Bell
Keyword(s):  
Micronucleus Assay ◽  
The United States ◽  
Fda Approval ◽  
History Of ◽  
Good Laboratory ◽  
History Of Use ◽  
Mutation Assay ◽  
Forward Mutation

Benzocaine has a long history of use in human medicine. However, benzocaine also has been used in aquaculture with finfish for more than 40 years for sedating fish for marking, transport, surgery, and so on, although benzocaine does not have a current Food and Drug Administration (FDA) approval for this application in the United States. As part of a FDA approval for use as an animal drug, the genotoxicity of benzocaine was evaluated in the in vitro bacterial reverse mutation assay and the forward mutation assay and in vivo in the mouse micronucleus assay. These studies were conducted in compliance with Good Laboratory Practice regulations and according to Veterinary International Conference on Harmonisation guidelines. Based on the results of these studies, benzocaine was determined not to be genotoxic.

scholarly journals In vitro antioxidant and ex vivo anti-cataract activity of ethanolic extract of Cineraria maritima: a traditional plant from Nilgiri hills

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sumit Durgapal ◽  
Vijay Juyal ◽  
Anurag Verma
Keyword(s):  
Oxidative Stress ◽  
Ex Vivo ◽  
Ethanolic Extract ◽  
Antioxidant Potential ◽  
Aerial Parts ◽  
History Of ◽  
Underlying Causes ◽  
History Of Use ◽  
Cineraria Maritima

Abstract Background Cineraria maritima has a long history of use in the treatment of cataract and other eye-related problems in the homeopathic system of medicines. High oxidative stress is one of the major underlying causes of cataract which results in the precipitation of natural protein present in the lenses with aging. This research has been carried out to determine the anti-cataract activity of C. maritima by performing various antioxidant techniques such as 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, hydrogen peroxide, and studies in oxidative stress–induced ex vivo cataract model. Results Results of the study conducted in the ethanolic extract of aerial parts (leaves and stems) of C. maritima revealed the presence of various phytoconstituents such as alkaloids, phenols, flavonoids, etc. Total phenol and total flavonoid content was found to be 6.31 ± 0.06 % w/w and 2.14 ± 0.09% w/w respectively, which revealed that the plant contains a good amount of these compounds and hence possesses good antioxidant activity. Furthermore, IC50 values obtained from all the methods gave strong evidence regarding the antioxidant potential of this plant. Anti-cataract activity was also investigated using goat eye lenses and promising results were obtained which speak voluminously about its anti-cataract potential and support its well-prescribed use. Conclusion Results obtained with this study clearly supported the significant antioxidant potential and anti-cataract activity of this plant. Further, this plant demands great attention for the development of suitable novel dosage forms for the effective treatment of cataract.

scholarly journals Algae as potential repository of anti cancerous natural compounds

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Ankita Mridha ◽  
Santanu Paul
Keyword(s):  
Anticancer Agents ◽  
Biological Activities ◽  
Leukemia Cell ◽  
Relevant Information ◽  
Cancer Cell Growth ◽  
History Of ◽  
History Of Use ◽  
Promising Source

<p>Algae constitute a promising source of novel compounds with potential as human therapeutic agents. In particular, algae have been considered as a potential source of new bio-active compound. Algae possess several biological activities, including anticancer activity. This review provides a comprehensive report on the several genera of algae belonging to Chlorophyceae, Pheophyceae and Rhodophyceae having anti-proliferative, apoptotic, anti angiogenic as well as cytotoxic efficacy and their mode of action <em>in vitro</em> as well as <em>in vivo</em> condition. Algae are extensively used as functional foods and medicinal herbs, and have a long history of use in Asian countries. Many algae have been used for the treatment of cancer, many crude or partially purified polysaccharides from various brown, green, and red algae have been tested for their antitumor activities. Relevant information was collected from scientific journals, books, and reports via library and electronic search using Medline, Pubmed, Science Direct, and Scopus. The different extracts with some other solvent shows a huge anti-proliferative action on different cancer as well as on different leukemia cell lines. Here we focus on several bioactive compounds that have been derived as well as characterized from different genera of algae and there mechanism of inhibiting cancer cell growth. Considering the ability of the golden treasure present in algae to act against different cancers, this review highlights the potential use of algae as anticancer agents.</p>

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