Identification of Gingerols in Ginger (Zingiber officinale Roscoe) by High Performance Liquid Chromatography-Tandem Mass Spectrometry and Pharmacologic Studies of its Aqueous Extract on the Rabbit Isolated Duodenum Contractility

Abstract

Ginger (Zingiber officinale Roscoe, Zingiberaceae) is a plant used in traditional medicine in Cote d’Ivoire, notably for asthma attacks. In various medical traditions, rhizome of the plant is indicated as a cough-drop, antipyretic, anti-emetic, anti-inflammatory and physiologic functions stimulant. Gingerols and related compounds were identified as being its major active compounds. In this study, liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) coupled with diode array detection (DAD) was used to identify gingerol-related compounds from crude extracts of ginger rhizoma from Cote d’Ivoire. The isometric contractile force of rabbit duodenum strips was recorded in the presence of aqueous extract. 27 gingerol-related compounds were identified by LC-ESI-MS/MS-DAD in the methanolic crude extracts of ginger rhizoma. Short treatments (24 hours) of mice with the the aqueous extract of ginger (EZo) gave LD50 values of 1242.54 ± 8 mg/kg of b.w. and of 1089.6 ± 12 mg/kg of b.w., respectively by the method of Miller and Tainter and the method of Dragstedt and Lang. Our observation regarding the isolated duodenum of rabbit revealed that EZo was decreased the basal tonus and contractile force. For low concentration of EZo, the amplitude of this smooth muscle was increased but at higher concentration the amplitude was decreased. Chemical analysis allowed us to identify [8]-gingerol as the major phenyl-propanoid in the studied batch. Pharmacologic study confirmed that ginger aqueous extract was lightly toxic substance by intraperitoneal administration and evidenced that it had relaxing and antihistaminic activity on the duodenum.