A recent in vivo study in pigs demonstrated the hypotensive properties of essential oil extracted from the blossoming plant Elsholtzia ciliata. This study was designed to examine the effect of E. ciliata essential oil (EO) on smooth muscle contraction. Tension measurements were performed on prostate strips and intact aortic rings isolated from rats. Results showed that EO caused a concentration-dependent reduction in phenylephrine-induced contraction of both the prostate and aorta, with a more pronounced inhibitory effect in the prostate. The IC50 of EO for the prostate was 0.24 ± 0.03 µL/mL (n = 10) and for the aorta was 0.72 ± 0.11 µL/mL (n = 4, p < 0.05 vs. prostate). The chromatographic analysis identified elsholtzia ketone (10.64%) and dehydroelsholtzia ketone (86.23%) as the predominant compounds in the tested EO. Since both compounds feature a furan ring within their molecular structure, other furan ring-containing compounds, 2-acetylfuran (2AF) and 5-methylfurfural (5MFF), were examined. For the first time, our study demonstrated the relaxant effects of 2AF and 5MFF on smooth muscles. Further, results showed that EO, 2AF, and 5MFF altered the responsiveness of prostate smooth muscle cells to phenylephrine. Under control conditions, the EC50 of phenylephrine was 0.18 ± 0.03 µM (n = 5), while in the presence of EO, 2AF, or 5MFF, the EC50 values were 0.81 ± 0.3 µM (n = 5), 0.89 ± 0.11 µM (n = 5), and 0.69 ± 0.23 µM (n = 4), respectively, p < 0.05 vs. control. Analysis of the affinity of EO for α1-adrenergic receptors in the prostate suggested that EO at a certain range of concentrations has a competitive antagonistic effect on α1-adrenergic receptors. In conclusion, EO elicits a relaxant effect on smooth muscles which may be related to the inhibition of α1-adrenoreceptors.
Optical mapping is recognized as a promising tool for the registration of electrical activity in the heart. Most cardiac optical mapping experiments are performed in ex vivo isolated heart models. However, the electrophysiological properties of the heart are highly influenced by the autonomic nervous system as well as humoral regulation; therefore, in vivo investigations of heart activity in large animals are definitely preferred. Furthermore, such investigations can be considered the last step before clinical application. Recently, two comprehensive studies have examined optical mapping approaches for pig hearts in situ (in vivo), likely advancing the methodological capacity to perform complex electrophysiological investigations of the heart. Both studies had the same aim, i.e., to develop high-spatiotemporal-resolution optical mapping suitable for registration of electrical activity of pig heart in situ, but the methods chosen were different. In this brief review, we analyse and compare the results of recent studies and discuss their translational potential for in situ cardiac optical mapping applications in large animals. We focus on the modes of blood circulation that are employed, the use of different voltage-sensitive dyes and their loading procedures, and ways of eliminating contraction artefacts. Finally, we evaluate the possible scenarios for optical mapping (OM) application in large animals in situ and infer which scenario is optimal.
Background/Objectives: Furan derivatives are commonly encountered in food and environmental matrices and may exert biological effects, but their acute cardiovascular actions and potential mitochondrial targets remain insufficiently characterised. This study examined the effects of two simple furan compounds, 2-acetylfuran (2AF) and 5-methylfurfural (5MFF), on arterial blood pressure in vivo and on oxidative phosphorylation in isolated rat liver mitochondria. Methods: Arterial blood pressure was recorded invasively in anaesthetised rats after intraperitoneal administration of 2AF or 5MFF (0.3 µL/g). Systolic, diastolic, and mean arterial pressures, as well as heart rate, were monitored over time. Mitochondrial respiration was assessed in isolated rat liver mitochondria using high-resolution respirometry. Results: Both 2AF and 5MFF induced a rapid hypotensive response, with significant reductions in systolic, diastolic, and mean arterial pressures within 10–15 min after administration. MAP was reduced to a similar extent by both compounds. However, their chronotropic and pulse pressure responses differed: 5MFF increased heart rate and pulse pressure, whereas 2AF induced a delayed bradycardic response without a significant change in pulse pressure. In isolated liver mitochondria, both compounds markedly reduced ADP-stimulated respiration and decreased the respiratory control index, indicating reduced coupling efficiency. Both compounds also increased the cytochrome c effect, suggesting partial impairment of outer mitochondrial membrane integrity. Conclusions: 2AF and 5MFF exert acute hypotensive effects in anaesthetised rats and impair oxidative phosphorylation in isolated rat liver mitochondria. This study provides the first in vivo evidence that 2AF and 5MFF exert hypotensive effects and identifies them as bioactive furan compounds with dual haemodynamic and bioenergetic actions.
Background/Objectives: Transient receptor potential melastatin 7 (TRPM7) is a multifunctional ion channel-kinase containing a structurally resolved vanilloid-like (VL) regulatory region. Elsholtzia ketone (EK) and dehydroelsholtzia ketone (DEK), major ketones of Elsholtzia ciliata essential oil, are associated with cardiovascular effects, but their molecular target spectrum remains incompletely defined. We investigated whether EK and DEK can access and maintain structurally plausible configurations within the CCT128930-defined TRPM7 VL region. Methods: The 2.45 Å cryo-EM structure of mouse TRPM7 bound to CCT128930 (PDB 8W2L; M05) was prepared in an explicit lipid membrane and subjected to restrained minimization. The workflow combined repeated M05 redocking, blind and focused docking, RICS-based within-ligand pose selection, pose clustering, property-matched decoy controls, and 100-ns explicit-membrane molecular dynamics (MD). Results: Minimization preserved the VL architecture and all 12 M05 reference contacts. Ten independent M05 redocking runs recovered native-like poses in every run (best direct heavy-atom RMSD, 0.567 Å), although these ranked only 8–10 by Vina energy. Blind docking independently sampled the VL region for M05, EK, and DEK. Focused docking identified recurrent EK and DEK pose families reproducing 10/12 M05 contacts (Jaccard = 0.833). Property-matched decoys reached comparable high-end contact similarity, showing that reference compatibility was not ligand-specific. During MD, M05 showed the strongest positional and contact retention, EK intermediate redistribution, and DEK greater copy-dependent heterogeneity. Conclusions: EK and DEK can adopt M05-compatible geometries within the TRPM7 VL region, providing experimentally testable structural hypotheses. However, docking similarity and RICS do not demonstrate affinity, selectivity, potency, or functional TRPM7 modulation.