Pharmacological activity and safety profile of P10358, a novel, orally active acetylcholinesterase inhibitor for Alzheimer's disease

J Pharmacol Exp Ther. 1997 Feb;280(2):710-20.

Abstract

1-[(3-Fluoro-4-pyridinyl)amino]-3-methyl-1(H)-indol-5-yl methyl carbamate (P10358) is a potent, reversible acetylcholinesterase inhibitor that produces central cholinergic stimulation after oral and parental administration in rats and mice. P10358 is a 2.5 times more potent acetylcholinesterase inhibitor than THA in vitro (IC50 = 0.10 +/- 0.02 microM vs. IC50 = 0.25 +/- 0.03 microM). It also inhibits butyrylcholinesterase activity as potently as THA (IC50 = 0.08 +/- 0.05 microM vs. IC50 = 0.07 +/- 0.01 microM). Ex vivo, P10358 (0.2 - 20 mg/kg, p.o.) produced dose-dependent inhibition of brain acetylcholinesterase activity. At 10 and 20 mg/ kg, it produced profound and long-lasting hypothermia in mice. P10358 enhanced performance in rats in a step-down passive avoidance task (0.62 and 1.25 mg/kg) and in a social recognition paradigm (0.32, 0.64 and 1.25 mg/kg) in mice. It reversed scopolamine-induced deficits in the Morris Water maze in rats (1.25 and 2.5 mg/kg) and a higher dose elevated striatal homovanillic acid levels. These behavioral and biochemical effects are consistent with central cholinergic stimulation. Hemodynamic studies in the rat demonstrated a 16-fold separation between behaviorally active doses (1.25 mg/kg) and those that elevated arterial pressure (20 mg/kg). Lethality in rats occurred at an oral dose of 80 mg/kg, but not at lower doses. Chemically, P10358 is an N-aminoindole and may not have the hepatotoxic liability associated with aminoacridine structure of tacrine. P10358 had weak affinity (>10 microM) at a variety of aminergic and peptidergic receptors and uptake carriers. These properties suggest that P10358 may be a safe and promising symptomatic treatment for Alzheimer's disease.

MeSH terms

  • Acetylcholinesterase / metabolism
  • Administration, Oral
  • Alzheimer Disease / drug therapy
  • Aminopyridines / administration & dosage
  • Aminopyridines / therapeutic use
  • Aminopyridines / toxicity*
  • Animals
  • Avoidance Learning / drug effects
  • Brain / drug effects
  • Brain / metabolism*
  • Butyrylcholinesterase / metabolism
  • Carbamates / administration & dosage
  • Carbamates / therapeutic use
  • Carbamates / toxicity*
  • Cholinesterase Inhibitors / administration & dosage
  • Cholinesterase Inhibitors / therapeutic use
  • Cholinesterase Inhibitors / toxicity*
  • Corpus Striatum / metabolism
  • Dopamine / metabolism*
  • Female
  • Humans
  • Hypothermia, Induced*
  • Kinetics
  • Male
  • Maze Learning / drug effects*
  • Memory
  • Mice
  • Mice, Inbred Strains
  • Ovariectomy
  • Prosencephalon / enzymology
  • Rats
  • Rats, Wistar
  • Scopolamine / pharmacology
  • Social Behavior
  • Space Perception
  • Time Factors

Substances

  • Aminopyridines
  • Carbamates
  • Cholinesterase Inhibitors
  • P 10358
  • Scopolamine
  • Acetylcholinesterase
  • Butyrylcholinesterase
  • Dopamine