Rapid in vivo screening method for the evaluation of new anti helicobacter medicinal preparations

Abstract

The objective of this study was to devise a rapid mouse model for the in vivo screening of new anti Helicobacter pylori products. Six to eight week-old mice pre-treated (7 days) with Amoxicillin/Metronidazole (25 mg/kg) to eliminate all Helicobacter-like organisms were inoculated (4x per week) with 200 µl of a bacterial culture (108 CFU/ml of H. pylori CCUG-39500). Colonisation of mouse stomach was assessed from day 1 to 15 post inoculation by the Gram stain, rapid urease test and antral mucus culture. These findings were used as a mouse model of Helicobacter pylori infection to assess the in vivo anti Helicobacter activities of two plant-derived molecules with proven cytoprotective, ulcer healing and in vitro anti Helicobacter properties (TN, a tabersonine chloride alkaloid from the fruits of Voacanga Africana and PAL, a protoberberine alkaloid ((7,8-dihydro-8-hydroxy-palmatine) from the bark of Enantia chlorantha). For up to 6 days post inoculation, the test organisms were recoverable by culture from 87.5% of the antral mucus samples while 100% of Gram stains were positive. The infection tended to clear naturally from day 9. Fifteen days post infection, only Gram stains were still positive (37.5%). Three-day oral administration of TN, PAL (50 mg/kg) and Metronidazole (25 mg/kg) completely eliminated the bacterial strain from the gastric antral mucus compared with the controls. This 4-week model is proposed as a rapid screening tool for in vivo evaluation of new anti H. pylori products in order to select candidates for detailed investigations.

African Journal of Traditional, Complementary and Alternative Medicines Vol. 3(4) 2006: 102-114