The biological properties of aspartame. II. Actions involving the gastrointestinal system

Aspartame (APM) was investigated in several pharmacological tests to delineate any effects on the gastrointestinal system. The compound did not affect food consumption at one hour following a single intragastric dose of 200 mg/kg in rats. There was no evidence of inhibition or stimulation of the gastric juice secretion rate, the concentration of gastric acid, acid output or proteolytic activity following an intragastric dose of 250 mg/kg in five-hour pylorus-ligated rats. Likewise, APM at the same dosage did not significantly affect gastric ulceration induced by nineteen hours of pylorus-ligation. In several in vitro tests it was demonstrated that APM did not affect the proteolytic activity of pepsin or the lipolytic activity of pancreatic lipase at concentrations of 143 microgram and 1.25 mg/ml, respectively. Its anticholinergic activity was found to be insignificant, less than 0.001 times the potency of atropine sulfate, when measured against acetylcholine-induced contraction of isolated rabbit ileum. These data indicate that APM may be devoid of undesirable side effects on the gastrointestinal tract when used as a food sweetening agent.