Dementia is a chronic progressive mental disorder, which adversely affects memory, thinking, comprehension, calculation and language. Some of the most common dementias are Alzheimer’s disease, Parkinsonism, Dementia with Lewy Bodies and Myasthenia gravis. All of these disorders are related to abnormalities in the central cholinergic system, which shows a decline in acetylcholine (ACh) level due...

Arsenic is an environmental toxicant, and one of the major mechanisms by which it exerts its toxic effect is through an impairment of cellular respiration by inhibition of various mitochondrial enzymes, and the uncoupling of oxidative phosphorylation. Most toxicity of arsenic results from its ability to interact with sulfhydryl groups of proteins and enzymes, and to substitute phosphorus in a v...

A new method of producing butyrylcholinesterase (BChE) preparations, stable in storage and use, has been proposed. The BChE preparation is the enzyme co-immobilized with 0.2 M 5-5′-dithiobis (2-nitrobenzoic acid) starch or gelatin gel. All experimental preparations retain activity for at least 300 d. based on gel show higher but lower sensitivity to toxicants tested this study compared gel-base...

Emblica officinalis (Family: Euphorbiaceae) commonly known as Indian Gooseberry or Amla, is widely used in Ayurveda for its memory enhancing, anti-aging, anti-stress and antioxidant properties. This study evaluated the anti-cholinesterase activity of an aqueous extract from the fruits of Emblica officinalis as these are the key enzymes involved in cholinergic transmission. Cholinesterase inhibi...

Recent world-wide terrorist events associated with the threat of hazardous chemical agent proliferation, and outbreaks of chemical contamination in the food supply has demonstrated an urgent need for sensors that can directly detect the presence of dangerous chemical toxins. Such sensors must enable real-time detection and accurate identification of different classes of pesticides (e.g., carbam...

Traditionally, drugs were discovered by testing compounds manufactured in time consuming multi-step processes against a battery of in vivo biological screens. Promising compounds were then further studied in development, where their pharmacokinetic properties, metabolism and potential toxicity were investigated. Here we present a study on herbal lead compounds and their potential binding affini...

The effectiveness of physostigmine and atropine pretreatment against the lethal effects of sarin was studied in rats given lethal subcutaneous injections (130 micrograms/kg) of the organophosphate. Pretreatment of these animals with physostigmine 30 min prior to injection of sarin reduced mortality to 28% and when the drug coadministered with atropine only 4% of the animals died. The latter tre...

In vivo effects of reversible inhibitors of cholinesterase activity were determined radiometrically in undiluted samples of erythrocytes and plasma. [14C]acetylcholine at substrate saturation, 25 degrees C and pH 7.4 permitted rapid and precise determination of butyrylcholinesterase (EC 3.1.1.8) and acetylcholinesterase (EC 3.1.1.7) activities. Reference values for acetylcholinesterase and buty...

An enzymatic ion exchange model for active sodium transport is described. Kinetic equations relating net flux to time, and to concentration difference across the actively transporting membrane are derived. The second of these equations is tested, using the isolated frog skin in the "short-circuit" apparatus of Ussing. Reasonable lineaxity, as predicted by this equation, is observed. The passive...

A rapid and economical method is reported for the preparation of an immobilized enzyme reactor (IMER) using silica-encapsulated equine butyrylcholinesterase (BuChE) as a model system. Peptide-mediated silica formation was used to encapsulate BuChE, directly immobilizing the enzyme within a commercial pre-packed column. The silica/enzyme nanocomposites form and attach simultaneously to the metal...