A method for measuring cholinesterase activity in human saliva and its application to farmers and consumers

Salivary Acetylcholinesterase Activity Is Increased in Parkinson’s Disease: A Potential Marker of Parasympathetic Dysfunction

“…The catalytic activity of AChE was determined by the colorimetric method [ 17 ], used on salivary samples with slight modifications [ 13 ]. For each measurement, 100 μ L of saliva and 25 μ L of 10 mM dithionitrobenzene (DTNB) (Sigma-Aldrich, Missouri, USA) were added to 750 μ L of 0.1 M phosphate buffer (pH = 8).…”

“…AChE has therefore been considered a potential biomarker of cholinergic function in general, and blood AChE levels were utilized in biomonitoring of pesticide exposure [ 11 , 12 ]. Altered levels of salivary AChE activity have also been detected in patients exposed to pesticides, and this approach has recently been explored as an alternative to blood measurements in monitoring pesticide exposure [ 13 ]. Furthermore salivary AChE activity has been proposed as a potential test for central cholinergic function in patients with Alzheimer's disease [ 14 ].…”

Cholinesterase Activity in the Eye?

“…Curiously, higher cholinesterase activity was observed in the vitreous humor and posterior cavities, so the authors suggest that the origin of this activity can occur from retinal tissue 35 . Despite, underestimating BuChE activity for years as a cholinergic indicator and recent studies in fluids such as saliva, and serum, attribute its importance in the measurement of cholinergic activity 48,49 . Therefore, the fact that there is cholinesterase activity of BuChE could be associated with the parasympathetic state.…”

“…Several studies show that the measurement of AChE is possible in body fluid such as blood, serum, urine, saliva, and cerebrospinal fluid, so it could be speculated that through the tear fluid the activity can be evaluated by enzymatic assay of AChE or BuChE 49,73 , considering the volumes required for the reaction 74 . For example, Ellman´s method is one of the most used assays to evaluate BuChE, and although some authors describe its activity as not specified, others show that BuChE activity in saliva can provide relevant information on cholinergic alterations such as the area in two particular cases: Alzheimer´s disease and neurotoxicity due to pesticides, where it occurs as a loss of cholinergic neurons, two situations that area of the public health problems worldwide 48,75,76 .…”

“…For example, Ellman´s method is one of the most used assays to evaluate BuChE, and although some authors describe its activity as not specified, others show that BuChE activity in saliva can provide relevant information on cholinergic alterations such as the area in two particular cases: Alzheimer´s disease and neurotoxicity due to pesticides, where it occurs as a loss of cholinergic neurons, two situations that area of the public health problems worldwide 48,75,76 . Furthermore, Thiphom et al demonstrated that in farmers exposed to pesticides, the plasma and saliva levels of BuChE are correlated in the two fluids and decreases in the population exposed to pesticides 49 , in this sense, the possibility of evaluating the enzymatic activity in tear fluids, is highly interesting due to its low cost and less invasiveness. Therefore, I suggest, research to evaluated non only AChE in saliva but also in tears using a test with greater sensitivity, even though the concentrations of some biomolecules that are evidenced in blood, in the tear show a lower concentration, and additional evaluation is correlated with other visual and ocular functions with cholinergic activity.…”