Antispasmodic activity and mechanism of action of polyherbal formulation DCD-684 on rabbit jejunum

Digas colic drops (DCD-684) is a polyherbal formulation containing decoctions of five medicinal plants namely Carum carvi L., Foeniculum vulgare Mill, Mentha arvensis L., Mentha piperita L. and Zingiber officinale Roscoe. These plants have been extensively used in traditional medicine for the treatment of various gastrointestinal diseases including abdominal colic. This study was conducted to determine the spasmolytic effect of DCD-684 (100% v/v) and its individual plant components on isolated rabbit jejunum (in vitro) and their possible mechanism of action. The effects were evaluated on spontaneous and pre-contracted tissues using KCl (80mM) and other contractile agonists including acetylcholine (0.3µM), carbamylcholine (0.3µM), serotonin (10 µM) and histamine (100µM) in the presence and absence of DCD-684. The various concentrations of DCD-684 (0.1-3% v/v) demonstrated spasmolytic effects on both spontaneous (IC50=0.75%) and KCl-induced contractions (IC₅₀=1.6%), respectively. It also inhibited the contractions induced by acetylcholine (IC₅₀=0.45%), carbamylcholine (IC₅₀=0.95%), serotonin (IC50=0.95%) and histamine (IC₅₀=0.87%). The DCD-684 exhibited synergistic effect due to its five plant components suggesting that spasmolytic cascade is probably governed by muscarinic and/or nicotinic receptors, serotonergic histaminergic, as well as calcium channel blocking mechanisms. Thereby, providing the pharmacological basis of its therapeutic use in the gastrointestinal motility disorders and related inflammatory ailments.