Journal: Scientific Reports

Article Title: Tectorigenin induces vasorelaxation in porcine coronary arteries through activation of Kv channels and oestrogen receptor modulation

doi: 10.1038/s41598-025-20988-6

Figure Lengend Snippet: Involvement of potassium channels in tectorigenin-induced vasorelaxation in porcine coronary arteries. ( A ) Effects of various potassium channel blockers on vasorelaxation induced by 30 µM tectorigenin. Pretreatment with glibenclamide (10 µM), iberiotoxin (IbTX, 200 nM), tetraethylammonium (TEA, 1 mM), apamin (100 nM), or charybdotoxin (1 µM) did not significantly affect the relaxant response ( p > 0.05), whereas 4-aminopyridine (4-AP, 1 mM) significantly attenuated tectorigenin-induced relaxation ( p < 0.05). ( B ) Concentration-dependent inhibitory effect of 4-AP (1 mM) on tectorigenin-induced relaxation. Significant inhibition was observed at 10 and 30 µM († p < 0.05 vs. corresponding tectorigenin alone), but not at 100 µM. ( C ) Comparison of the relaxant effects of 30 µM tectorigenin in porcine coronary arteries pre-contracted with either 100 nM U46619 or 80 mM KCl. Tectorigenin elicited significant vasorelaxation in U46619-pre-contracted rings but had negligible effect in KCl-contracted rings. Data are expressed as mean ± standard error of the mean (SEM) from four independent hearts. U46619 plateau (normalised to 60 mM KCl) was similar across groups ( p > 0.05; Supplementary Table 2).

Article Snippet: For experimental assays, a range of pharmacological agents was utilised, including U46619, apamin, KT5720, KT5823, and L-NNA (Sigma-Aldrich, MO, USA); rolipram, vardenafil, and TEA (Santa Cruz Biotechnology, CA, USA); IbTX (Alomone Labs, Jerusalem, Israel); glibenclamide (Research Biochemicals International, MA, USA); TTX and 4-AP (Tocris Bioscience, Bristol, UK); CTX (Bachem, Bubendorf, Switzerland); and charybdotoxin, methyl-piperidino-pyrazole (MPP), and PHTPP (Cayman Chemical, MI, USA).

Techniques: Concentration Assay, Inhibition, Comparison

Journal: bioRxiv

Article Title: Natural xanthones as α-Mangostin induce vasorelaxation via binding to key gating residues in the S6 domain of BK channels

doi: 10.1101/2025.10.02.680041

Figure Lengend Snippet: (A) Representative whole-cell current traces of BKα/β1 channels alone and BKα/β1 coexpressed with Ca v 1.2 channels before and after application of 10 µM α-Mangostin. Currents were measured in Ca i 2+ -free conditions in a physiological potassium gradient with a family of voltage steps from -50 mV to +50 mV in 10 mV increments. The inset shows voltage activation with a family protocol up to +200 mV to show the presence of BKα/β1 channels. (B) Currents of BKα/β1 channels and BKα/β1 – Ca v complexes before and after application of 10 µM α-Mangostin plotted against voltage. The last panel shows the α-Mangostin-activated currents for the range -50 to 10 mV obtained by subtracting the current before α-Mangostin application from the current after application for each potential (mean ± SEM, n=8-11 for each condition). (C) Representative contraction force recordings of aortic preparations from mice. 10 µM α-Mangostin were either applied directly to aortic preparations precontracted with 100 nM Noradrenaline (NA; top), or the precontracted preparations were incubated with 100 nM Iberiotoxin (IbTx) before α-Mangostin application and the contraction force was analyzed 10 min after α-Mangostin addition (dotted lines in recordings). The bar graph shows the normalized contraction force of preparations as mean ± SEM together with the median (orange). Data and statistics see Table S13.

Article Snippet: BC5 (Arg-4-methoxy-2-naphthylamine) was obtained from MP Biomedicals (Irvine, USA), and Iberiotoxin from Alomone Labs (Jerusalem, Israel).

Techniques: Activation Assay, Incubation