Assessment of antiemetic activity of dihydrocoumarin: In vivo and in silico approaches on receptor binding affinity and modulatory effects

Dihydrocoumarin (DCN) is a natural compound widely used in the flavor industry and has antioxidant and anti-inflammatory properties. However, its potential antiemetic effects on gastrointestinal disturbances remain untested. This study emphasizes assessing the antiemetic properties of the natural aromatic compound DCN using copper sulfate (CuSO₄.5H₂O)-induced emetic model on chicks, and an in silico approach was also adopted to estimate the possible underlying mechanisms. Two doses (25 and 50 mg/kg b.w.) of DCN and several referral drugs considered positive controls (PCs), including domperidone (6 mg/kg), hyoscine (21 mg/kg), aprepitant (16 mg/kg), diphenhydramine (10 mg/kg), and ondansetron (5 mg/kg), were orally administered to chicks. The vehicle was provided as the control group. Co-treatments of DCN with referral drugs were also provided to chicks to evaluate the modulatory action of the test compound. According to the results, DCN delayed the emetic onset and decreased the frequency of retches in a dose-dependent manner compared to the vehicle group. DCN (50 mg/kg) represented a notable delayed latency period (61.17 ± 4.12 s) and a diminished number of retchings (17.67 ± 1.82 times) compared to the control group. Further, in the co-treatments, DCN increased the latency period and reduced the number of retches, except for domperidone. In the in silico investigation, DCN showed notable binding affinity toward the D₂ (−7 kcal/mol), H₁ (−7.5 kcal/mol), and M₅ (−7 kcal/mol) receptors in the same binding site as the referral ligand. Our research indicates that DCN has mild antiemetic properties by interacting with the D₂, H₁, and M₅ receptors. Therefore, several pre-clinical and clinical studies are necessary to assess the effectiveness and safety profile of this food ingredient.