Effect of 6-methyl-5-hepten-2-one (Sulcatone) on hemostasis parameters in SHR rats: In Silico, In Vitro, and In Vivo...

Sulcatone is a compound found in citrus fruits and citronella oil, and it exhibits biological effects on the cardiovascular system. This study aimed to investigate the pharmacokinetic and pharmacodynamic aspects of sulcatone through in silico analysis and to evaluate its vasorelaxant, antioxidant, and hemostatic effects in spontaneously hypertensive rats (SHR). To refine the investigation, in silico evaluation was performed using the ADMET-AI, SwissADME, Protox 3.0, and AutoDock v1.5.7 platforms. In non-clinical studies, SHR rats were used (approved by the Institutional Animal Care and Use Committee-CEUA). Aortic rings were isolated for assessment of vasorelaxant response and morphometric analysis. Hemostatic parameters (platelet aggregation and coagulation) were also evaluated. For the antioxidant and coagulation analysis, animals were treated orally (p.o.) with sulcatone or saline for 7 days. In silico results demonstrated that sulcatone has high intestinal absorption, does not violate Lipinski's rule, does not inhibit cytochrome P450 isoenzymes, and presents no predicted toxicity risk. Sulcatone interacts with amino acid residues at the active site of the calmodulin (CaM) protein target. Sulcatone induced vasorelaxation both in the presence (EC₅₀ = 3.8 ± 0.3 × 10⁻⁵ M) and absence of vascular endothelium (EC₅₀ = 3.9 ± 0.4 × 10⁻⁵ M), with no statistically significant difference between the values. Morphometric analysis of the aorta revealed reduced wall thickness and increased diameter of aortic rings. Assessment of antithrombotic activity of sulcatone (10⁻⁹ to 10⁻⁷ M) demonstrated an anti-platelet aggregation effect (1.5 ± 0.64%; 1.25 ± 0.47%; 2.5 ± 0.5%, respectively) compared to ADP-induced aggregation (43.75 ± 1.79%), an effect enhanced in the presence of calmodulin inhibitor (calmidazolium). Sulcatone at doses of 50 and 75 mg/kg reduced nitrite levels (7.22 ± 0.33 and 6.0 ± 0.61 mmol/L, respectively), and at 100 mg/kg increased GSH levels (1128 ± 25.37 mmol/L). In the coagulation analysis (PT and aPTT), sulcatone-treated SHR rats showed prolonged times (25.44 ± 1.47 s and 21.28 ± 0.71 s, respectively) compared to Wistar rats (21.91 ± 0.87 s and 25.44 ± 1.47 s, respectively). However, sulcatone treatment at 50, 75, and 100 mg/kg (p.o.) did not present anticoagulant activity. In conclusion, sulcatone demonstrated favorable pharmacokinetic predictions and exerted vasorelaxant and anti-platelet aggregation effects, possibly through a shared mechanism involving interaction with calmodulin active site residues and intracellular calcium modulation. Additionally, sulcatone exhibited antioxidant properties and a low risk of bleeding, as it did not compromise the coagulation pathways.