© 1996 Oxford University Press
research-article |
Inhibition of Human Plasma and Serum Butyrylcholinesterase (EC 3.1.1.8) by 
-Chaconine and -Solanine1
*University of Florida, IFAS, Citrus Research and Education Center 700 Experiment Station Road. Lake Alfred, Florida 33850
Received March 15, 1996; accepted July 31, 1996
The purpose of these experiments was to determine the reversibility of 
-chaconine and -solanine inhibition of human plasma butyrylcholinesterase (BuChE). For the substrate -naphthylacetate, optimal assay conditions were 0.50 M sodium phosphate buffer and a substrate concentration of 3–5 ' 10–4 M. Dibucaine (1 ' 10–5 M) indicated the usual phenotype for all subjects; -chaconine and -solanine at 2.88 ' 10–6 M inhibited BuChE about 70 and 50%, respectively. One-and 24-hr incubations at 1 ' 10–1 M with -chaconine, -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. -Chaconine and -solanine are reversible inhibitors of human butyrylcholinesterase. At estimated tissue levels, -chaconine, -solanine, and solanidine inhibited BuChE 10–86%. In assays which combined -chaconine, -solanine, and solanidine, inhibition of BuChE was less than additive. No inhibition of albumin -naphthylacetate esterase (an arylesterase) was noted with any inhibitor. The importance of these data to adverse toxicological effects of potato alkaloids is discussed.