In vitro and in silico analysis of the vascular effects of asymmetrical N,N-bis(alkanol)amine aryl esters, novel multidrug resistance-reverting agents

Abstract

Asymmetrical N,N-bis(alkanol)amine aryl esters (FRA77, GDE6, and GDE19) are potent multidrug resistance (MDR) reversers. Their structures loosely remind that of the Ca(2+) antagonist verapamil. Therefore, the aim of this study was to investigate their vascular activity in vitro. Their effects on the mechanical activity of fresh and cultured rat aorta rings on Cav1.2 channel current (I Ca1.2) of A7r5 cells and their cytotoxicity on A7r5 and EA.hy926 cells were analyzed. Docking at the rat α1C subunit of the Cav1.2 channel was simulated in silico. Compounds tested were cytotoxic at concentrations >1 μM (FRA77, GDE6, GDE19) and >10 μM (verapamil) in EA.hy926 cells, or >10 μM (FRA77, GDE6, GDE19) and at 100 μM (verapamil) in A7r5 cells. In fresh rings, the three compounds partly antagonized phenylephrine and 60 mM K(+) (K60)-induced contraction at concentrations ≥1 and ≥3 μM, respectively. On the contrary, verapamil fully relaxed rings pre-contracted with both agents. In cultured rings, 10 μM GDE6, GDE19, FRA77, and verapamil significantly reduced the contractile response to both phenylephrine and K60. Similarly to verapamil, the three compounds docked at the α1C subunit, interacting with the same amino acids residues. FRA77, GDE6, and GDE19 inhibited I Ca1.2 with IC50 values 1 order of magnitude higher than that of verapamil. FRA77-, GDE6-, and GDE19-induced vascular effects occurred at concentrations that are at least 1 order of magnitude higher than those effectively reverting MDR. Though an unambiguous divergence between MDR reverting and vascular activity is of overwhelming importance, these findings consistently contribute to the design and synthesis of novel and potent chemosensitizers.

Vascular Toxicity Risk Assessment of MC18 and MC70, Novel Potential Diagnostic Tools for In Vivo PET Studies

“…K + currents were blocked with 30 mM TEA in the external solution and Cs + in the internal solution. Current values were corrected for leakage and residual outward currents using 10 μM nifedipine, which completely blocked I Ca1.2 .…”

Vasorelaxant Effects Induced by Red Wine and Pomace Extracts of Magliocco Dolce cv.

“…Functional integrity of smooth muscle was assessed by recording the response of the rings to 0.3 µM phenylephrine. The presence of a functional or dysfunctional endothelium was indicated by a ≥75% or ≤10% acetylcholine-induced relaxation, respectively, of the phenylephrine-induced tone [34,35] In some experiments, preparations were pre-incubated with either 100 µM L-NAME (eNOS inhibitor) for 30 min, or with 5 µM capsazepine (selective TRPV1 channel blocker) for 20 min [33]. Then, phenylephrine was added to the organ bath to elicit contraction and the effects of LDC extracts assessed always in the presence of the inhibitor or blocker.…”

Vasorelaxing Activity of R-(−)-3′-Hydroxy-2,4,5-trimethoxydalbergiquinol from Dalbergia tonkinensis: Involvement of Smooth Muscle CaV1.2 Channels

“…The 3D homology model of Ca V 1.2 channel pore domain was employed, as previously described [36,45]. As a DBQ 3D structure was not available in databases of chemical molecules, it was first drawn on the basis of its analogue [(R)-2,4,5-trimethoxydalbergiquinol with PubChem CID 44 257 555], adding a hydroxyl group in the 3′ position, and then downloaded in mol format using MolView [46].…”