Effect of rikkunshito on gastric sensorimotor function under distention

Area of Science:

• Gastroenterology
• Pharmacology
• Psychosomatic Medicine

Background:

• Rikkunshito is an herbal medicine used for gastrointestinal symptoms.
• Its effects on human gastric function, particularly under stress, are not well understood.
• Psychosocial stress can induce visceral hypersensitivity, a process potentially modulated by rikkunshito.

Purpose of the Study:

• To investigate the effects of rikkunshito on stress-induced gastric hypersensitivity in humans.
• To determine if rikkunshito alters gastric wall tone and accommodation under stress.

Main Methods:

• Nine healthy volunteers received either rikkunshito or placebo for two weeks, followed by a washout period.
• Gastric sensorimotor function was assessed using a gastric barostat.
• Virtual reality was used to induce psychosocial stress during measurements.

Main Results:

• Stress significantly increased heart rate and gastric volume, while decreasing sensory and pain thresholds.
• Rikkunshito reduced epigastric fullness and perceived stress.
• Rikkunshito inhibited stress-induced reductions in gastric volume and anxiety.

Conclusions:

• Rikkunshito may improve symptoms of gastric hypersensitivity.
• The herbal medicine appears to enhance gastric accommodation under stress.
• These findings suggest a potential therapeutic role for rikkunshito in stress-related functional dyspepsia.