Antidiarrhoeal and intestinal modulatory activities of Wei-Chang-An-Wan extract

Wei-Chang-An-Wan (WCAW), a traditional pharmaceutical preparation, has been used for treating various gastrointestinal (GI) diseases for several decades, but it is still poorly understood how it works on those disorders. This study was to investigate the effects of WCAW extract on GI tract.

The activities of the methanol extract (ME) of WCAW on castor oil-induced diarrhoea, gastrointestinal transit (GIT) in mice, and contractions of isolated rabbit jejunum were investigated. We further assessed the safety of ME in vivo. Additionally, a HPLC fingerprint of ME was appraised to ensure its chemical consistency.

Ten peaks were identified in the HPLC fingerprint of ME. At the doses of 400 and 800 mg/kg, ME significantly protected mice against castor oil-induced diarrhoea as well as the number of faeces and wet faeces. Interestingly, administration of ME significantly accelerated GIT in normal mice and reduced stimulated GIT induced by neostigmine. ME also dose-dependently attenuated spontaneous contractions of the isolated rabbit jejunum, and those induced by acetylcholine (Ach) and neostigmine. Moreover, oral administration of ME up to 5 g/kg did not produce any toxic effects. Taken together, ME is able to inhibit diarrhoea, increase normal GIT, and decrease GIT induced by neostigmine, which indicate that ME might play a bidirectional role in GI tract.

Our study provides a scientific basis for the clinical use of WCAW.