Abstract: Objective: The aim is to explore the effect and mechanism of Chinese rice wine (CRW) on the contraction activity of the isolated small intestine of rats. Methods: The isolated small intestine was treated separately with low, medium, high concentrations of CRW, alcohol and CRW without polyphenols. A RM6240 multi-channel physiological signal acquisition system was used to record intestinal motility. The protein expression of choline acetyltransferase (ChAT) and nitric oxide synthase (NOS) in intestinal myenteric plexus was measured by immunohistochemistry and Western blot. Results: Compared with the control group, medium and high-dose CRW (3.5% and 10.0%, V/V) obviously inhibited the amplitude of intestinal contraction with percentage inhibition of 58% and 100%, respectively. Medium-dose ethanol had no significant impact on intestinal contraction, but high-dose ethanol significantly inhibited the amplitude of intestinal contraction with a percentage inhibition of 47.5%. Medium and high-dose CRW without polyphenols significantly inhibited the contractile amplitude of the isolated small intestine by 48% and 67%, respectively, but the efficacy was inferior to that of CRW. Compared with the control group, the expression of ChAT in intestinal myenteric plexus in the CRW group significantly decreased, while the expression of NOS significantly increased. Conclusion: The effect of CRW on contraction of isolated small intestine is related to its ingredient ethanol and polyphenols, by inhibiting the release of acetylcholine (ACh) as an excitatory neurotransmitter and enhancing the release of NO as an inhibitory neurotransmitter from intestinal myenteric plexus. CRW can affect the activity of neurons in the myenteric plexus, inhibit the movement of small intestine, and slow down the hyperactivity of gastrointestinal function, which will provide new clues to the health-benefiting effects of CRW.

Key words: Chinese rice wine, contractile activity of small intestine, myenteric plexus, acetylcholine, nitric oxide