Inhibition of Human Plasma and Serum Butyrylcholinesterase (EC 3.1.1.8) by α-Chaconine and α-Solanine

Abstract

The purpose of these experiments was to determine the reversibility of a-chaconine and a-solanine inhibition of human plasma butyrylcholinesterase (BuChE). For the substrate a-naphthylacetate, optimal assay conditions were 0.50 M sodium phosphate buffer and a substrate concentration of 3-5 X 10~4 M. Dibucaine (1 X 10~5 M) indicated the usual phenotype for all subjects; achaconine and a-solanine at 2.88 X 10~6 M inhibited BuChE about 70 and 50%, respectively. One-and 24-hr incubations at 1 X 10~! M with a-chaconine, a-solanine, paraoxon, eserine, and ethanol yielded reversible inhibition with dilution except for paraoxon. Twenty-four-hour dialyses of incubations showed no inhibition except for paraoxon. PAGE enzyme activity gels of 1-and 24-hr incubations also showed no inhibition except for paraoxon. aChaconine and a-solanine are reversible inhibitors of human butyrylcholinesterase. At estimated tissue levels, a-chaconine, a-solanine, and solanidine inhibited BuChE 10-86%. In assays which combined a-chaconine, a-solanine, and solanidine, inhibition of BuChE was less than additive. No inhibition of albumin a-naphthylacetate esterase (an arylesterase) was noted with any inhibitor. The importance of these data to adverse toxicological effects of potato alkaloids is diSCUSSed. C 1996 SodMy of Toxicology.Potatoes, consumed by humans for at least 2000 years (Spoerke, 1994;Ugent, 1970), contain the steroidal alkaloids, a-chaconine, a-solanine, and solanidine. The toxicology of these known butyryl-and acetylcholinesterase inhibitors (Harris and Whittaker, 1962;Orgell, 1963) has been reviewed

Blood Cholinesterases as Human Biomarkers of Organophosphorus Pesticide Exposure

“…Dawson (1990) showed RBC AChE inhibition by tacrine is independent of time, is reversed by dilution, decreases with increasing substrate concentration, and is reversed by dialysis. An experiment with these criteria for a reversible inhibitor (and conversely for irreversible inhibition) has been conducted for potato alkaloids (Nigg et al 1996). a-Chaconine and a-solanine were found to be reversible inhibitors of human plasma BChE (Nigg et al 1996).…”

“…An experiment with these criteria for a reversible inhibitor (and conversely for irreversible inhibition) has been conducted for potato alkaloids (Nigg et al 1996). a-Chaconine and a-solanine were found to be reversible inhibitors of human plasma BChE (Nigg et al 1996). Based on the discovery of potent AChE inhibitors (alkaloids, huperzine A, and huperzine B) from Huperzia serrata, a Chinese folk medicine, we are likely to discover other "natural" anticholinesterases in folk medicines and foods (Tang et al 1988;Kozikowski et al 1991).…”

Effect of feeding solanidine, solasodine and tomatidine to non-pregnant and pregnant mice

“…The reported toxicity of glycoalkaloids a due to anticholinesterase effects on the central nervous system (Duan, 1995;Nigg et al, 1996) and disruption of cell membranes (Blankemeyer et al, 1992(Blankemeyer et al, , 1998. Symptoms of glycoalkaloid toxicity experienced by humans include colic pain in the abdomen and stomach, gastroenteritis, diarrhea, vomiting, burning sensation about the lips and mouth, hot skin, fever, rapid pulse and headache.…”

Molecular mechanisms of toxicity of important food-borne phytotoxins

“…The mechanism of this inhibition was shown to be reversible and at a concentration of 2.88610 -5 M a-chaconine and a-solanine were shown to inhibit BuChE by about 70% and 50%, respectively [190]. Changes in the glycoalkaloid content of potatoes may occur during storage, under the influence of light and radiation, following mechanical damage and as a result of food processing.…”