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

Repurposing Castanea sativa Spiny Burr By-Products Extract as a Potentially Effective Anti-Inflammatory Agent for Novel Future Biotechnological Applications

The concept of a "circular bioeconomy" holds great promise for the health, cosmetic, and nutrition sectors by re-using Castanea sativa (Mill.) by-products. This sustainable resource is rich in bioactive secondary metabolites with antioxidant and anti-inflammatory properties. By transforming these by-products into high-value products for human health, we can promote sustainable economic growth and reduce the environmental impact of traditional waste disposal, adding value to previously underutilized resources. In the present study, we investigated the antioxidant capacity, phytochemical composition, and in vitro antioxidant and anti-inflammatory activity of C. sativa burr (CSB) aqueous extract. The spectrophotometric study revealed high total phenolic content (TPC) values with significant antioxidant and anti-radical properties. Using UPLC-MS/MS techniques, the phytochemical investigation identified 56 metabolites, confirming the presence of phenolic compounds in CSBs. In addition, CSBs significantly downregulated pro-inflammatory mediators in LPS-stimulated RAW 264.7 macrophage cells without significant cell toxicity. Lastly, in silico studies pinpointed three kinases from RAW 264.7 cells as binding partners with ellagic acid, the predominant compound found in our extract. These findings strongly advocate for the recycling and valorization of C. sativa by-products, challenging their conventional classification as mere "waste".

Phytochemical Composition, Anti-Inflammatory Property, and Anti-Atopic Effect of Chaetomorpha linum Extract

Utilizing plant-based resources, particularly their by-products, aligns with sustainability principles and circular bioeconomy, contributing to environmental preservation. The therapeutic potential of plant extracts is garnering increasing interest, and this study aimed to demonstrate promising outcomes from an extract obtained from an underutilized plant waste. Chaetomorpha linum, an invasive macroalga found in the Orbetello Lagoon, thrives in eutrophic conditions, forming persistent mats covering approximately 400 hectares since 2005. The biomass of C. linum undergoes mechanical harvesting and is treated as waste, requiring significant human efforts and economic resources-A critical concern for municipalities. Despite posing challenges to local ecosystems, the study identified C. linum as a natural source of bioactive metabolites. Phytochemical characterization revealed lipids, amino acids, and other compounds with potential anti-inflammatory activity in C. linum extract. In vitro assays with LPS-stimulated RAW 264.7 and TNF-α/IFN-γ-stimulated HaCaT cells showed the extract inhibited reactive oxygen species (ROS), nitric oxide (NO), and prostaglandin E2 (PGE2) productions, and reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions via NF-κB nuclear translocation, in RAW 264.7 cells. It also reduced chemokines (TARC/CCL17, RANTES/CCL5, MCP-1/CCL2, and IL-8) and the cytokine IL-1β production in HaCaT cells, suggesting potential as a therapeutic candidate for chronic diseases like atopic dermatitis. Finally, in silico studies indicated palmitic acid as a significant contributor to the observed effect. This research not only uncovered the untapped potential of C. linum but also laid the foundation for its integration into the circular bioeconomy, promoting sustainable practices, and innovative applications across various industries.

A Drug Discovery Approach to a Reveal Novel Antioxidant Natural Source: The Case of Chestnut Burr Biomass

Currently, many environmental and energy-related problems are threatening the future of our planet. In October 2022, the Worldmeter recorded the world population as 7.9 billion people, estimating that there will be an increase of 2 billion by 2057. The rapid growth of the population and the continuous increase in needs are causing worrying conditions, such as pollution, climate change, global warming, waste disposal, and natural resource reduction. Looking for novel and innovative methods to overcome these global troubles is a must for our common welfare. The circular bioeconomy represents a promising strategy to alleviate the current conditions using biomass-like natural wastes to replace commercial products that have a negative effect on our ecological footprint. Applying the circular bioeconomy concept, we propose an integrated in silico and in vitro approach to identify antioxidant bioactive compounds extracted from chestnut burrs (an agroforest waste) and their potential biological targets. Our study provides a novel and robust strategy developed within the circular bioeconomy concept aimed at target and drug discovery for a wide range of diseases. Our study could open new frontiers in the circular bioeconomy related to target and drug discovery, offering new ideas for sustainable scientific research aimed at identifying novel therapeutical strategies.

Dynamin-independent CaV1.2 and KCa1.1 channels regulation and vascular tone modulation by the mitochondrial fission inhibitors dynasore and dyngo-4a

A role for mitochondrial fission in vascular contraction has been proposed based on the vasorelaxant activity of the dynamin (and mitochondrial fission) inhibitors mdivi-1 and dynasore. However, mdivi-1 is capable to inhibit Ba2+ currents through CaV1.2 channels (IBa1.2), stimulate KCa1.1 channel currents (IKCa1.1), and modulate pathways key to the maintenance of vessel active tone in a dynamin-independent manner. Using a multidisciplinary approach, the present study demonstrates that dynasore, like mdivi-1, is a bi-functional vasodilator, blocking IBa1.2 and stimulating IKCa1.1 in rat tail artery myocytes, as well as promoting relaxation of rat aorta rings pre-contracted by either high K+ or phenylephrine. Conversely, its analogue dyngo-4a, though inhibiting mitochondrial fission triggered by phenylephrine and stimulating IKCa1.1, did not affect IBa1.2 but potentiated both high K+- and phenylephrine-induced contractions. Docking and molecular dynamics simulations identified the molecular basis supporting the different activity of dynasore and dyngo-4a at CaV1.2 and KCa1.1 channels. Mito-tempol only partially counteracted the effects of dynasore and dyngo-4a on phenylephrine-induced tone. In conclusion, the present data, along with previous observations (Ahmed et al., 2022) rise caution for the use of dynasore, mdivi-1, and dyngo-4a as tools to investigate the role of mitochondrial fission in vascular contraction: to this end, a selective dynamin inhibitor and/or a different experimental approach are needed.

Artificial intelligence-driven identification of morin analogues acting as CaV1.2 channel blockers: Synthesis and biological evaluation

Morin is a vasorelaxant flavonoid, whose activity is ascribable to Ca_V1.2 channel blockade that, however, is weak as compared to that of clinically used therapeutic agents. A conventional strategy to circumvent this drawback is to synthesize new derivatives differently decorated and, in this context, morin-derivatives able to interact with Ca_V1.2 channels were found by employing the potential of PLATO in target fishing and reverse screening. Three different derivatives (5a-c) were selected as promising tools, synthesized, and investigated in in vitro functional studies using rat aorta rings and rat tail artery myocytes. 5a-c were found more effective vasorelaxant agents than the naturally occurring parent compound and antagonized both electro- and pharmaco-mechanical coupling in an endothelium-independent manner. 5a, the series' most potent, reduced also Ca²⁺ mobilization from intracellular store sites. Furthermore, 5a≈5c > 5b inhibited Ba²⁺ current through Ca_V1.2 channels. However, compound 5a caused also a concentration-dependent inhibition of K_Ca1.1 channel currents.

Targeting neuronal calcium channels and GSK3β for Alzheimer's disease with naturally-inspired Diels-Alder adducts

The complexity of neurodegenerative diseases, among which Alzheimer's disease plays a pivotal role, poses one of the tough therapeutic challenges of present time. In this perspective, a multitarget approach appears as a promising strategy to simultaneously interfere with different defective pathways. In this paper, a structural simplification plan was performed on our previously reported multipotent polycyclic compounds, in order to obtain a simpler pharmacophoric central core with improved pharmacokinetic properties, while maintaining the modulating activity on neuronal calcium channels and glycogen synthase kinase 3-beta (GSK-3β), as validated targets to combat Alzheimer's disease. The molecular pruning approach applied here led to tetrahydroisoindole-dione (1), tetrahydromethanoisoindole-dione (2) and tetrahydroepoxyisoindole-dione (3) structures, easily affordable by Diels-Alder cycloaddition. Preliminary data indicated structure 3 as the most appropriate, thus a SAR study was performed by introducing different substituents, selected on the basis of the commercial availability of the furan derivatives required for the synthetic procedure. The results indicated compound 10 as a promising, structurally atypical, safe and BBB-penetrating Ca_v modulator, inhibiting both L- and N-calcium channels, likely responsible for the Ca²⁺ overload observed in Alzheimer's disease. In a multitarget perspective, compound 11 appeared as an effective prototype, endowed with improved Ca_v inhibitory activity, with respect to the reference drug nifedipine, and encouraging modulating activity on GSK-3β.

Sdox, a H2S releasing anthracycline, with a safer profile than doxorubicin toward vasculature

Sdox is a synthetic H₂S-releasing doxorubicin (Dox) less cardiotoxic and more effective than Dox in pre-clinical, Dox-resistant tumour models. The well-known anthracycline vascular toxicity, however, might limit Sdox clinical use. This study aimed at evaluating Sdox vascular toxicity in vitro, using Dox as reference compound. Both vascular smooth muscle A7r5 and endothelial EA.hy926 cells were more sensitive to Dox than Sdox, although both drugs equally increased intracellular free radical levels. Sdox released H₂S in both cell lines. The H₂S scavenger hydroxocobalamin partially reverted Sdox-induced cytotoxicity in A7r5, but not in EA.hy926 cells, suggesting a role for H₂S in smooth muscle cell death. Markers of Sdox-induced apoptosis were significantly lower than, in A7r5 cells, and comparable to those of Dox in EA.hy926 cells. In A7r5 cells, Dox increased the activity of caspase 3, 8, and 9, Sdox affecting only that of caspase 3. Moreover, both drugs induced comparable DNA damage in A7r5 cells, while Sdox was less toxic than Dox in Ea.hy926 cells. In fresh aorta rings, only Dox weakly increased phenylephrine-induced contraction when endothelium was present. In rings cultured with both drugs for 7 days, Sdox blunted phenylephrine- and high K⁺-induced contractions though at a concentration 10-fold higher than that of Dox. In conclusion, Sdox may represent the prototype of an innovative anthracycline, effective against Dox-resistant tumours, displaying a more favourable vascular toxicity profile compared to the parent compound.

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

Several epidemiological studies demonstrate that moderate (red) wine consumption may afford protection against cardiovascular diseases. Protection is ascribed to the biological activity of wine components, many of which, however, are discarded during winemaking. In vitro rat thoracic aorta rings contracted with phenylephrine or KCl were used to assess the vasorelaxant activity of extracts from wine pomaces (seeds and skins) of the Calabrian autochthonous grape variety Magliocco dolce (Arvino). NMR spectroscopy was used to ascertain their chemical composition. Data demonstrate that seed and skin, but not must, extracts are capable of relaxing vascular preparations in an endothelium-dependent manner, similarly to the red wine extract, due to the presence of comparable amounts of bioactive constituents. In rings pre-contracted with 20–30 mM KCl, only seed extracts showed a moderate relaxation. The most efficacious vasodilating extract (wine) showed a good antioxidant profile in both [(2,2-diphenyl-1-picrylhydrazyl)acid] radical (DPPH) and [2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)] radical (ABTS) assays. In conclusion, winemaking from Magliocco dolce grape can provide potentially health-promoting by-products useful in cardiovascular disease management.

Applications of in Silico Methods for Design and Development of Drugs Targeting Protein-Protein Interactions

BACKGROUND

Identification of Protein-Protein Interactions (PPIs) is a major challenge in modern molecular biology and biochemistry research, due to the unquestionable role of proteins in cells, biological process and pathological states. Over the past decade, the PPIs have evolved from being considered a highly challenging field of research to being investigated and examined as targets for pharmacological intervention.

OBJECTIVE

Comprehension of protein interactions is crucial to known how proteins come together to build signalling pathways, to carry out their functions, or to cause diseases, when deregulated. Multiplicity and great amount of PPIs structures offer a huge number of new and potential targets for the treatment of different diseases.

METHODS

Computational techniques are becoming predominant in PPIs studies for their effectiveness, flexibility, accuracy and cost. As a matter of fact, there are effective in silico approaches which are able to identify PPIs and PPI site. Such methods for computational target prediction have been developed through molecular descriptors and data-mining procedures.

RESULTS

In this review, we present different types of interactions between protein-protein and the application of in silico methods for design and development of drugs targeting PPIs. We described computational approaches for the identification of possible targets on protein surface and to detect of stimulator/ inhibitor molecules.

CONCLUSION

A deeper study of the most recent bioinformatics methodologies for PPIs studies is vital for a better understanding of protein complexes and for discover new potential PPI modulators in therapeutic intervention.

MC225, a Novel Probe for P-glycoprotein PET Imaging at the Blood-brain Barrier: In Vitro Cardiovascular Safety Evaluation

The P-glycoprotein (P-gp) substrate MC225, at concentrations ≤10 nM, is a valuable radiotracer for positron emission tomography imaging of P-gp function in rats and mice. The aim of this study was to evaluate its potential toxic hazard toward the cardiovascular system through an in-depth analysis of its effects on rat aorta rings, on CaV1.2 channel current (ICa1.2) of A7r5 cells and on Langendorff-perfused rat heart. In aortic rings, MC225 relaxed phenylephrine-induced contraction in a concentration-dependent and endothelium-independent manner, with an IC50 value of about 1 μM. At concentrations ≥3 μM, it antagonized the response to cumulative concentrations of K. MC225, 1 and 10 μM, inhibited ICa1.2 by 15% and 31%, respectively, without affecting either current activation or inactivation kinetics. In Langendorff-perfused rat hearts, only 10 μM MC225 significantly decreased left ventricular pressure and increased coronary perfusion pressure while reducing heart rate and prolonging the cardiac cycle length as well as the atrioventricular conduction time (PQ interval) on the electrocardiogram. Lower concentrations of the drug were ineffective. These findings demonstrate that MC225-induced cardiovascular effects took place at concentrations that are at least 2 orders of magnitude higher than those allowing in vivo measurement of P-gp function. Therefore, MC225 represents a promising positron emission tomography tool for in vivo straightforward P-gp quantification.

In vitro vascular toxicity of tariquidar, a potential tool for in vivo PET studies

The P-glicoprotein (P-gp) inhibitor tariquidar is used to detect functional alterations of blood brain barrier pumps in PET imaging. The doses required, however, up to 4-fold higher than those already used in clinical trials to reverse multidrug resistance, cause syncopal episode and hypotension. Therefore, the effects of these doses toward the vasculature were investigated and an in-depth analysis of tariquidar-mediated effects on A7r5 and EA.hy926 cells viability, on the mechanical activity of freshly and cultured rat aorta rings and on L-type Ca²⁺ current [I_Ca(L)] of A7r5 cells has been performed. In both A7r5 and EA.hy926 cells, tariquidar was not cytotoxic up to 1μM concentration. On the contrary, at 10μM, it caused apoptosis already after 24h treatment. In fresh aorta rings, 10μM tariquidar partially relaxed phenylephrine-, but not 60mM K⁺ (K60)-induced contraction. In rings treated with 10μM tariquidar for 7days, the contractile response to both phenylephrine and K60 remained unchanged. Finally, tariquidar did not modify I_Ca1.2 intensity and kinetics. In conclusion, Tariquidar might exert both cytotoxic and acute, weak vascular effects at concentrations comparable to those employed in PET imaging. This implies that caution should be exercised when using it as diagnostic tool.

Cav1.2 channel current block by the PKA inhibitor H-89 in rat tail artery myocytes via a PKA-independent mechanism: Electrophysiological, functional, and molecular docking studies

To characterize the role of cAMP-dependent protein kinase (PKA) in regulating vascular Ca²⁺ current through Ca_v1.2 channels [I_Ca1.2], we have documented a marked capacity of the isoquinoline H-89, widely used as a PKA inhibitor, to reduce current amplitude. We hypothesized that the I_Ca1.2 inhibitory activity of H-89 was mediated by mechanisms unrelated to PKA inhibition. To support this, an in-depth analysis of H-89 vascular effects on both I_Ca1.2 and contractility was undertaken by performing whole-cell patch-clamp recordings and functional experiments in rat tail main artery single myocytes and rings, respectively. H-89 inhibited I_Ca1.2 with a pIC₅₀ (M) value of about 5.5, even under conditions where PKA activity was either abolished by both the PKA antagonists KT5720 and protein kinase inhibitor fragment 6-22 amide or enhanced by the PKA stimulators 6-Bnz-cAMP and 8-Br-cAMP. Inhibition of I_Ca1.2 by H-89 appeared almost irreversible upon washout, was charge carrier- and voltage-dependent, and antagonised by the Ca_v1.2 channel agonist (S)-(-)-Bay K 8644. H-89 did not alter both potency and efficacy of verapamil, did not affect current kinetics or voltage-dependent activation, while shifting to the left the 50% voltage of inactivation in a concentration-dependent manner. H-89 docked at the α_1C subunit in a pocket region close to that of (S)-(-)-Bay K 8644 docking, forming a hydrogen bond with the same, key amino acid residue Tyr-1489. Finally, both high K⁺- and (S)-(-)-Bay K 8644-induced contractions of rings were fully reverted by H-89. In conclusion, these results indicate that H-89 inhibited vascular I_Ca1.2 and, consequently, the contractile function through a PKA-independent mechanism. Therefore, caution is recommended when interpreting experiments where H-89 is used to inhibit vascular smooth muscle PKA.

The surge of flavonoids as novel, fine regulators of cardiovascular Cav channels

Ion channels underlie a wide variety of physiological processes that involve rapid changes in cell dynamics, such as cardiac and vascular smooth muscle contraction. Overexpression or dysfunction of these membrane proteins are the basis of many cardiovascular diseases that represent the leading cause of morbidity and mortality for human beings. In the last few years, flavonoids, widely distributed in the plant kingdom, have attracted the interest of many laboratories as an emerging class of fine ion, in particular Ca_v, channels modulators. Pieces of in vitro evidence for direct as well as indirect effects exerted by various flavonoids on ion channel currents are now accumulating in the scientific literature. This activity may be responsible, at least in part, for the beneficial and protective effects of dietary flavonoids toward cardiovascular diseases highlighted in several epidemiological studies. Here we examine numerous studies aimed at analysing this feature of flavonoids, focusing on the mechanisms that promote their sometimes controversial activities at cardiovascular Ca_v channels. New methodological approaches, such as molecular modelling and docking to Ca_v1.2 channel α_1c subunit, used to elucidate flavonoids intrinsic mechanism of action, are introduced. Moreover, flavonoid-membrane interaction, bioavailability, and antioxidant activity are taken into account and discussed.