Brief Article
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World J Gastroenterol. Jul 28, 2013; 19(28): 4582-4589
Published online Jul 28, 2013. doi: 10.3748/wjg.v19.i28.4582
Antinociceptive effect of berberine on visceral hypersensitivity in rats
Qing-Lin Tang, Min-Ling Lai, Yuan-Fu Zhong, Ai-Min Wang, Jun-Kai Su, Ming-Qing Zhang
Qing-Lin Tang, Min-Ling Lai, Yuan-Fu Zhong, Ai-Min Wang, Jun-Kai Su, Ming-Qing Zhang, Department of Gastroenterology, 175th Hospital of PLA, Affiliated Southeast Hospital of Xiamen University, Zhangzhou 363000, Fujian Province, China
Author contributions: Zhang MQ and Tang QL designed the research; Tang QL, Lai ML, Zhong YF and Wang AM performed the experiments; Tang QL and Su JK analyzed the data; Tang QL, Zhong YF, Su JK and Wang AM wrote and revised the manuscript; Zhang MQ supervised the whole research and revised the manuscript.
Correspondence to: Ming-Qing Zhang, Professor, Department of Gastroenterology, 175th Hospital of PLA, Affiliated Southeast Hospital of Xiamen University, No. 269 Middle Zhanghua Road, Zhangzhou 363000, Fujian Province, China. zhangmingqing20@163.com
Telephone: +86-596-2975571 Fax: +86-596-2975771
Received: May 13, 2013
Revised: May 28, 2013
Accepted: June 8, 2013
Published online: July 28, 2013
Processing time: 116 Days and 12.2 Hours
Abstract

AIM: To assess the protective effect of berberine administration and the role of nitric oxide (NO) in visceral hypersensitivity.

METHODS: Fifty male Sprague-Dawley rats were randomly assigned to five groups. An inflammatory bowel disease model was induced in rats by intracolonic instillation of 1 mL 4% acetic acid at 8 cm proximal to the anus for 30 s and restraint stress. After subsidence of inflammation on day 7 of the experiment, the rats were subjected to rectal distension, performed by a balloon (6-Fr, 2 mm external diameter, disposable silicon balloon-urethral catheter for pediatric use) which was rapidly inflated with increasing volumes of prewarmed (37 °C) water (0.1, 0.2, 0.3, 0.4, 0.6, 0.8 and 1 mL) for 30 s at four-minute intervals, and then the abdominal withdrawal reflex (AWR) and the level of fecal output were measured, respectively. AWR scores either 0, 1, 2, 3 or 4 were obtained by blinded observers. Rats had been pretreated with berberine or aminoguanidine (NO synthetase inhibitor) or berberine + aminoguanidine before measurement.

RESULTS: The rats in the placebo group showed a hypersensitive response to rectal distension (2.69 ± 0.08 vs 1.52 ± 0.08, P = 0.000) and defecated more frequently than those in the control group (5.0 ± 0.16 vs 0.44 ± 0.16, P = 0.000). Comparing the berberine with placebo group, the AWR scores were reduced for all distension volumes and were significant at 0.2-1 mL (1.90 ± 0.08 vs 2.69 ± 0.08, P = 0.000), while the numbers of hard pellets, soft pellets, formless stools, and total fecal output in the placebo group were significantly larger than in the berberine group (5.0 ± 0.16 vs 2.56 ± 0.16, P = 0.000). Administration of aminoguanidine or berberine + aminoguanidine before VH score measurement reversed the antinociceptive effect of berberine (2.52 ± 0.08 vs 1.90 ± 0.08, P = 0.000; 2.50 ± 0.08 vs 1.90 ± 0.08, P = 0.000). The numbers of hard pellets, soft pellets, formless stool, and total of fecal output in aminoguanidine group were significantly larger than the corresponding values in control group, berberine group, and berberine + aminoguanidine group (4.81 ± 0.16 vs 0.44 ± 0.16, P = 0.000; 4.81 ± 0.16 vs 2.56 ± 0.16, P = 0.000; 4.81 ± 0.16 vs 3.75 ± 0.16, P = 0.000). The berberine and berberine + aminoguanidine groups showed reduced defecation, but aminoguanidine alone did not reduce defecation (2.56 ± 0.16 vs 4.81 ± 0.16, P = 0.000; 3.75 ± 0.16 vs 4.81 ± 0.16, P = 0.000).

CONCLUSION: Berberine had an antinociceptive effect on visceral hypersensitivity, and NO might play a role in this effect.

Keywords: Berberine; Irritable bowel syndrome; Visceral hypersensitivity; Nitric oxide

Core tip: Berberine had an antinociceptive effect on visceral hypersensitivity. This effect was reduced by nitric oxide (NO) synthetase inhibitor, thus NO might play a role in the effect of berberine.