Antidiarrheal Potential of Psoralidin Through Modulation of <scp>COX</scp> , μ‐Opioid, and L‐Type Calcium Channel Signaling Pathways: In Vivo and In Silico Investigations

BACKGROUND: Psoralidin (PSN), a prenylated coumestrol, demonstrates a broad spectrum of pharmacological properties, such as anti-inflammatory, anticancer, anti-diabetic, and neuroprotective activities. This study aimed to evaluate the therapeutic potential of PSN as an antidiarrheal agent using in vivo experimentation in a castor oil-induced chick model, supported by in silico receptor-binding analyses. METHODS: Chicks were treated orally with PSN at doses of 5, 15, and 30 mg/kg and compared with standard reference drugs, including bismuth subsalicylate (BSS, 10 mg/kg), loperamide (LOP, 3 mg/kg), and nifedipine (NFN, 2.5 mg/kg). Diarrheal onset, stool frequency, and intestinal fluid secretion were recorded. Complementary molecular docking, pharmacokinetic, and toxicity assessments were performed to predict drug-receptor interactions and safety profiles. RESULTS: Among all treatment groups, PSN-15 at its most effective dose produced the most significant reduction in parameters, lowering the diarrheal secretion (DRS) score to 138.00 ± 2.91 mg and the number of stool output (NSO) to 6.80 ± 1.09 events compared to the NC group. In silico analysis demonstrated that PSN formed stable binding complexes with high binding affinity (BA) for cyclooxygenase-2 (COX-2) (-9.2 kcal/mol), as well as for μ-opioid receptor, COX-1, and L-type calcium channel. Computational toxicity profiling suggests a favorable preliminary safety profile for PSN. CONCLUSION: In conclusion, PSN demonstrated significant antidiarrheal activity by reducing stool frequency, intestinal secretion, and delaying onset of diarrhea, likely through multi-target modulation of COX, μ-opioid, and L-type calcium channel pathways. Nonetheless, future studies will focus on detailed pharmacokinetic profiling, long-term toxicity assessment, and validation of PSN's antidiarrheal efficacy in advanced preclinical models to support its therapeutic potential.