Antiemetic activity of abietic acid possibly through the 5HT3 and muscarinic receptors interaction pathways

Abstract

The present study was designed to evaluate the antiemetic activity of abietic acid (AA) using in vivo and in silico studies. To assess the effect, doses of 50 mg/kg b.w. copper sulfate (CuSO₄⋅5H₂O) were given orally to 2-day-old chicks. The test compound (AA) was given orally at two doses of 20 and 40 mg/kg b.w. On the other hand, aprepitant (16 mg/kg), domperidone (6 mg/kg), diphenhydramine (10 mg/kg), hyoscine (21 mg/kg), and ondansetron (5 mg/kg) were administered orally as positive controls (PCs). The vehicle was used as a control group. Combination therapies with the referral drugs were also given to three separate groups of animals to see the synergistic and antagonizing activity of the test compound. Molecular docking and visualization of ligand-receptor interaction were performed using different computational tools against various emesis-inducing receptors (D₂, D₃, 5HT₃, H₁, and M₁-M₅). Furthermore, the pharmacokinetics and toxicity properties of the selected ligands were predicted by using the SwissADME and Protox-II online servers. Findings indicated that AA dose-dependently enhances the latency of emetic retching and reduces the number of retching compared to the vehicle group. Among the different treatments, animals treated with AA (40 mg/kg) exhibited the highest latency (98 ± 2.44 s) and reduced the number of retching (11.66 ± 2.52 times) compared to the control groups. Additionally, the molecular docking study indicated that AA exhibits the highest binding affinity (- 10.2 kcal/mol) toward the M₄ receptors and an elevated binding affinity toward the receptors 5HT₃ (- 8.1 kcal/mol), M₁ (- 7.7 kcal/mol), M₂ (- 8.7 kcal/mol), and H₁ (- 8.5 kcal/mol) than the referral ligands. Taken together, our study suggests that AA has potent antiemetic effects by interacting with the 5TH₃ and muscarinic receptor interaction pathways. However, additional extensive pre-clinical and clinical studies are required to evaluate the efficacy and toxicity of AA.

Keywords: Gallus gallus domesticus; Abietic acid; Emesis; Molecular docking; Vomiting.

Figure 1

Chemical structures of abietic acid and reference drugs.

Figure 2

Latency observed in test samples, controls, and combinations [Values are the mean ± standard error of the mean (S.E.M.) (n = 6)]. ^aCompared to the control (vehicle), ^bcompared to the APT; ^ccompared to the DOM; ^dcompared to the DHM; ^ecompared to the HYS; ^fcompared to the OND; ^gcompared to the AA-20; ^hcompared to the AA-40; ⁱcompared to the DOM + AA-40; p < 0.05 (OND vs AA-20, AA-20 vs AA-40 + OND); p < 0.01 (OND Vs AA-40 + HYS); p < 0.001 (HYS vs AA-20, HYS vs AA-40 + HYS); p < 0.0001 (Vehicle vs DOM, vehicle vs AA-20, vehicle vs AA-40, vehicle vs AA-40 + DOM, vehicle vs AA-40 + HYS, vehicle vs AA-40 + OND, APT vs DOM, APT vs AA-20, APT vs AA-40, APT vs AA-40 + DOM, APT vs AA-40 + HYS, APT vs AA-40 + OND, DOM vs DHM, DOM vs HYS, DOM vs OND, DOM vs AA-20, DOM vs AA-40, DOM vs AA-40 + HYS, DOM vs AA-40 + OND, DHM vs AA-20, DHM vs AA-40, DHM vs AA-40 + DOM, DHM vs AA-40 + HYS, DHM vs AA-40 OND, HYS vs AA-40, HYS vs AA-40 + DOM, HYS vs AA-40 OND, OND vs AA-40, OND vs AA-40 + DOM, OND vs AA-40 + OND, AA-20 vs AA-40, AA-20 vs AA-40 + DOM, AA-40 vs AA-40 + DOM, AA-40 vs AA-40 + HYS, AA-40 vs AA-40 + OND, AA-40 + DOM vs AA-40 + HYS, AA-40 + DOM vs AA-40 + OND).

Figure 3

Number of retches observed in the test sample, controls, and combination [Values are mean ± standard error of the mean (SEM) (n = 6)]. ^aCompared to the control (vehicle), ^bcompared to the APT; ^ccompared to the DOM; ^dcompared to the DHM; ^ecompared to the HYS; ^fcompared to the OND; ^gcompared to the AA-20; ^hcompared to the AA-40; p < 0.05 (Vehicle vs DHM, DOM vs AA-40 + HYS, DHM vs OND, OND vs AA-40 + DOM, AA-40 vs AA-40 + HYS); p < 0.01 (vehicle vs HYS, HYS vs AA-40 + HYS, OND vs AA-40 + OND); p < 0.001 (DOM vs OND, DHM vs AA-40 + HYS, OND vs AA-40); p < 0.0001 (vehicle vs DOM, vehicle vs OND, vehicle vs AA-20, vehicle vs AA-40, vehicle vs AA-40 + DOM, vehicle vs AA-40 + HYS, vehicle vs AA-40 + OND, APT vs DOM, APT vs OND, APT vs AA-20, APT vs AA-40, APT vs AA-40 + DOM, APT vs AA-40 + HYS, APT vs AA-40 + OND, DOM vs DHM, DOM vs HYS, DHM vs AA-20, DHM vs AA-40, DHM vs AA-40 + DOM, DHM vs AA-40 + OND, HYS vs AA-20, HYS vs AA-40, HYS vs AA-40 DOM, HYS vs AA-40 + OND).

Figure 4

(i) The Swiss Model-built 3D structure of the human 5HT₃ receptor, (ii) Ramachandran plot of the homology model 5HT₃ protein for all non-glycine/proline residues.

Figure 5

3D and 2D view of protein–ligand interaction and their binding sites with related amino acid residues.

Figure 5

3D and 2D view of protein–ligand interaction and their binding sites with related amino acid residues.

Figure 6

Summary of physiochemical, toxicological, and pharmacokinetics properties of selected compounds. [The colored zone is the suitable physicochemical space for oral bioavailability; SIZE: 150 g/mol < MV < 500 g/mol; INSOLU (Insolubility): − 6 < log S (ESOL) < 0; LIPO (Lipophilicity): − 7 < XLOGP3 <  + 5.0; INSATU (In saturation): 0.25 < Fraction Csp3 < 1; POLAR (Polarity): 20 Ų < TPSA < 130 Ų; FLEX (Flexibility): 0 < num. rotatable bonds < 9].

Figure 7

The suggested anti-emetic mechanism of the test compound (abietic acid) compared to the selected standard drugs. [This Fig illustrates the anti-emetic mechanisms of APT, DOM, HYS, and OND, as well as a probable anti-emetic mechanism of AA, based on their affinity for binding to the muscarinic, D₂, D₃, 5HT₃, and NK₁ receptors. In this case, AA acts as an inhibitor of D₂, D₃, 5HT₃, M₄, and NK₁ receptors, while DOM, APT, OND, and HYS inhibit D₂, NK₁, 5HT₃, and muscarinic receptors, respectively. The vomiting center (medulla oblongata) is kept from being triggered when these stomach receptors are blocked, preventing muscular contraction, GIT contraction, and the outcome of no emesis].