Rice Bran Compound Shows Potential to Regulate Intestinal Activity

A recent study conducted by researchers at Toho University has uncovered that ferulic acid (FA), a polyphenol prevalent in rice bran, can effectively reduce intestinal smooth muscle contractions by inhibiting calcium influx through voltage-dependent channels. This discovery could pave the way for dietary strategies aimed at managing intestinal motility disorders, including irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).

The findings were published in the Journal of Pharmacological Sciences by a team led by Dr. Keisuke Obara and his colleagues. Ferulic acid is already recognized for its antioxidant and neuroprotective properties and is typically consumed through whole grains, particularly rice bran. However, its specific effects on gastrointestinal motility had not been thoroughly investigated until now.

Patients suffering from IBS and IBD often experience abnormal intestinal movements, which can manifest as either excessive or reduced motility. This study aimed to explore the influence of FA on such contractions within the gastrointestinal tract.

In laboratory experiments involving guinea pig ileal longitudinal smooth muscle (ILSM), the researchers found that FA significantly and reversibly inhibited contractions triggered by various neurotransmitters, including acetylcholine, histamine, prostaglandin F2?, and serotonin. The inhibition was characterized as noncompetitive and dependent on the concentration of FA used.

Further experiments utilizing vascular smooth muscle cell models demonstrated that FA reduced intracellular calcium levels elevated by potassium chloride, suggesting its role in modulating voltage-dependent calcium channels.

This research indicates that ferulic acid may act as a natural regulator of intestinal motility, potentially alleviating symptoms associated with diarrhea-predominant IBD by calming excessive muscle activity. However, caution is advised as FA could worsen symptoms in patients suffering from constipation-predominant IBS or in healthy individuals by excessively suppressing intestinal motility.

While the concentrations of FA shown to be effective in laboratory settings were higher than typical dietary levels, the researchers note that intestinal concentrations could be elevated following oral intake. Therefore, additional studies are necessary to evaluate the physiological relevance of these findings and their possible clinical applications.

The implications of this research highlight the potential for developing dietary interventions or supplements that utilize ferulic acid to target gut motility issues. Future clinical trials will be crucial to ascertain whether these laboratory effects can be replicated in human subjects, as well as to identify appropriate intake levels for achieving therapeutic benefits.