Ethnopharmacological validation of Capparis spinosa L. in gastrointestinal and respiratory disorders: Evidence from in vitro, in vivo, and in silico models.

Capparis spinosa L. is traditionally used in Pakistan to treat gastrointestinal and respiratory ailments, yet its multi-target pharmacological mechanisms remain poorly understood. To evaluate the traditional use of Capparis spinosa L. in asthma, diarrhea, and spasm using integrated in vitro, in vivo, and in silico approaches. Hydroethanolic extract of C. spinosa L. (Cap.Cr) was analyzed by LC ESI-MS/MS. Antispasmodic and bronchodilator activities of Cap.Cr and its fractions (Ethyl acetate, n-hexane, aqueous) were assessed using isolated jejunal segments from rabbit intestine, trachea, and urinary bladder. Antidiarrheal potential was assessed in mice using castor oil-induced diarrhea, enteropooling, and intestinal transit models. Rat fecal samples were analyzed via qRT-PCR to assess the presence of Firmicutes, Lactobacillus, and V2. Molecular docking explored interactions with calcium channels and muscarinic receptors. LC ESI-MS/MS study identified 26 bioactive flavonoids and alkaloids. In vitro, Cap.Cr and its fractions relaxed the contractions provoked by high K+ and carbachol (CCh) across all tissues. The extracts shifted the Ca2+ and carbachol cumulative response curves (CRCs), suggesting dicyclomine-like dual Ca2+ antagonistic and antimuscarinic mechanism. In vivo, C. spinosa (50-200 mg/kg) significantly (p < 0.05) lessened diarrheal episodes, fluid accumulation, and intestinal transit showing efficacy comparable to loperamide and atropine. Microbiota analysis indicated an increase in Firmicutes and Lactobacillus levels by C. spinosa. In silico docking suggested high binding affinities for muscarinic receptors (M3) and voltage-gated Ca2+ channels. C. spinosa L. exerts potent antispasmodic, bronchodilator, and antidiarrheal effects and may involve Ca2+ channel blockade and muscarinic antagonism, demonstrating pharmacological justification for its traditional use in gut and airway dysfunctions.