Spasmolytic Activity of Gentiana lutea L. Root Extracts on the Rat Ileum: Underlying Mechanisms of Action

The roots of Gentiana lutea L. are utilized in the preparation of various beverages and herbal remedies, serving as a traditional remedy for gastrointestinal ailments. The spasmolytic activity that could substantiate the traditional use of G. lutea root had not been investigated. The main objective goal of the study was to determine the validity of its use as a traditional remedy. The extraction of G. lutea root was performed using a 50% hydroethanolic solvent with three different extraction techniques: ultrasound-assisted extraction (UAE), heat-assisted extraction, and percolation. The spasmolytic activity was tested on isolated rat ileum. The mechanism of action was monitored using the models of spontaneous contractions and acetylcholine-, histamine-, CaCl2-, Bay K8644-, L-NAME-, ODQ-, apamin-, BaCl2-, charybdotoxin-, glibenclamide-, TRAM-34-, and quinine-modified contractions. UAE, having the best bioactivity, was further subjected to a liquid-liquid extraction fractionation. HPLC phytochemical analysis was performed for all tested extracts and fractions. Gentian root extracts were rich in secoiridoids, xanthones, and flavonoids. The UAE has shown better results on spontaneous contractions in comparison to its fractions, leading to the more detailed testing of its spasmolytic mechanism of activity. The extract's activity is primarily mediated through intermediate conductance Ca2+-activated K+ channels, ATP-sensitive K+ channels, voltage-sensitive K+ channels, and mechanisms that activate Ca2+ channels. Overall, the G. lutea root shows great potential in the treatment of spasmodic gastrointestinal ailments.

An In Vitro and In Silico Characterization of Salvia sclarea L. Methanolic Extracts as Spasmolytic Agents

The use of medicinal plant species and their products is widespread in the field of gastrointestinal and respiratory diseases. This study aimed to evaluate the traditional use of Salvia sclarea L., clary sage, finding the possible mechanisms of its spasmolytic and bronchodilator actions in in vitro conditions supported by molecular docking analysis, along with the antimicrobial effects. Four dry extracts were prepared from the aerial parts of S. sclarea, using absolute or 80% (v/v) methanol by the method of a single-stage maceration or an ultrasound-assisted extraction. Characterization of the bioactive compounds by high-performance liquid chromatography indicated the presence of significant amounts of polyphenolics, with rosmarinic acid as the prevalent one. The spontaneous ileal contractions were best inhibited by the extract prepared with 80% methanol and maceration. The same extract was superior in the carbachol- and KCl-induced tracheal smooth muscle contractions, being the strongest bronchodilator agent. The most powerful relaxation of KCl-induced ileal contractions was achieved with the extract made of absolute methanol by maceration, while the 80% methanolic extract made with the ultrasound method generated the best spasmolytic effects in the acetylcholine-induced ileal contractions. Docking analysis suggested that apigenin-7-O-glucoside and luteolin-7-O-glucoside exhibited the highest binding affinity to voltage-gated calcium channels. Gram (+) bacteria were more susceptible to the effects of the extracts, particularly Staphylococcus aureus, in contrast to Gram (-) bacteria and Candida albicans. This is the first study to point out the influence of S. sclarea methanolic extracts on the gastrointestinal and respiratory spasm reduction, paving the way for their potential place in complementary medicine.