scholarly journals Synthesis of New Water Soluble β-Cyclodextrin@Curcumin Conjugates and In Vitro Safety Evaluation in Primary Cultures of Rat Cortical Neurons

2021 ◽  
Vol 22 (6) ◽  
pp. 3255
Author(s):  
Amina Ben Mihoub ◽  
Samir Acherar ◽  
Céline Frochot ◽  
Catherine Malaplate ◽  
Frances T. Yen ◽  
...  

Self-aggregation of Curcumin (Cur) in aqueous biological environment decreases its bioavailability and in vivo therapeutic efficacy, which hampers its clinical use as candidate for reducing risk of neurodegenerative diseases. Here, we focused on the design of new Cur- β-Cyclodextrin nanoconjugates to improve the solubility and reduce cell toxicity of Cur. In this study, we described the synthesis, structural characterization, photophysical properties and neuron cell toxicity of two new water soluble β-CD/Cur nanoconjugates as new strategy for reducing risks of neurodegenerative diseases. Cur was coupled to one or two β-CD molecules via triazole rings using CuAAC click chemistry strategy to yield β-CD@Cur and (β-CD)2@Cur nanoconjugates, respectively. The synthesized nanoconjugates were found to be able to self-assemble in aqueous condition and form nano-aggregates of an average diameter size of around 35 and 120 nm for β-CD@Cur and (β-CD)2@Cur, respectively. The photophysical properties, water solubility and cell toxicity on rat embryonic cortical neurons of the designed nanoconjugates were investigated and compared to that of Cur alone. The findings revealed that both new nanoconjugates displayed better water solubility and in vitro biocompatibility than Cur alone, thus making it possible to envisage their use as future nano-systems for the prevention or risk reduction of neurodegenerative diseases.

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2196 ◽  
Author(s):  
Silvana Alfei ◽  
Anna Maria Schito ◽  
Guendalina Zuccari

Ursolic acid (UA) is a pentacyclic triterpenoid found in many medicinal plants and aromas endowed with numerous in vitro pharmacological activities, including antibacterial effects. Unfortunately, UA is poorly administered in vivo, due to its water insolubility, low bioavailability, and residual systemic toxicity, thus making urgent the development of water-soluble UA formulations. Dendrimers are nonpareil macromolecules possessing highly controlled size, shape, and architecture. In dendrimers with cationic surface, the contemporary presence of inner cavities and of hydrophilic peripheral functions, allows to encapsulate hydrophobic non-water-soluble drugs as UA, to enhance their water-solubility and stability, and to promote their protracted release, thus decreasing their systemic toxicity. In this paper, aiming at developing a new UA-based antibacterial agent administrable in vivo, we reported the physical entrapment of UA in a biodegradable not cytotoxic cationic dendrimer (G4K). UA-loaded dendrimer nanoparticles (UA-G4K) were obtained, which showed a drug loading (DL%) much higher than those previously reported, a protracted release profile governed by diffusion mechanisms, and no cytotoxicity. Also, UA-G4K was characterized by principal components analysis (PCA)-processed FTIR spectroscopy, by NMR and elemental analyses, and by dynamic light scattering experiments (DLS). The water solubility of UA-G4K was found to be 1868-fold times higher than that of pristine UA, thus making its clinical application feasible.


RSC Advances ◽  
2018 ◽  
Vol 8 (31) ◽  
pp. 17224-17236 ◽  
Author(s):  
Anastasia I. Solomatina ◽  
Shih-Hao Su ◽  
Maria M. Lukina ◽  
Varvara V. Dudenkova ◽  
Vladislav I. Shcheslavskiy ◽  
...  

Novel water-soluble iridium complexes with sulfonated diphosphine allow in vitro and in vivo lifetime hypoxia imaging.


Planta Medica ◽  
2019 ◽  
Vol 85 (16) ◽  
pp. 1233-1241
Author(s):  
Michael Kirchinger ◽  
Lara Bieler ◽  
Julia Tevini ◽  
Michael Vogl ◽  
Elisabeth Haschke-Becher ◽  
...  

AbstractThe chroman-like chalcone Xanthohumol C, originally found in hops, was demonstrated to be a potent neuroregenerative and neuroprotective natural product and therefore constitutes a strong candidate for further pharmaceutical research. The bottleneck for in vivo experiments is the low water solubility of this chalcone. Consequently, we developed and validated a suitable formulation enabling in vivo administration. Cyclodextrins were used as water-soluble and nontoxic complexing agents, and the complex of Xanthohumol C and 2-hydroxypropyl-β-cyclodextrin was characterized using HPLC, HPLC-MS, NMR, and differential scanning calorimetry. The water solubility of Xanthohumol C increases with increasing concentrations of cyclodextrin. Using 50 mM 2-hydroxypropyl-β-cyclodextrin, solubility was increased 650-fold. Furthermore, in vitro bioactivity of Xanthohumol C in free and complexed form did not significantly differ, suggesting the release of Xanthohumol C from 2-hydroxypropyl-β-cyclodextrin. Finally, a small-scaled in vivo experiment in a rat model showed that after i. p. administration of the complex, Xanthohumol C can be detected in serum, the brain, and the cerebrospinal fluid at 1 and 6 h post-administration. Mean (± SD) Xanthohumol C serum concentrations after 1, 6, and 12 h were determined as 463.5 (± 120.9), 61.9 (± 13.4), and 9.3 (± 0.8) ng/mL upon i. v., and 294.3 (± 22.4), 45.5 (± 0.7), and 13 (± 1.0) ng/mL after i. p. application, respectively. Accordingly, the formulation of Xanthohumol C/2-hydroxypropyl-β-cyclodextrin is suitable for further in vivo experiments and further pharmaceutical research aiming for the determination of its neuroregenerative potential in animal disease models.


2019 ◽  
Vol 9 (5) ◽  
pp. 419-428
Author(s):  
Li Li ◽  
Chunjiao Pan ◽  
Zhongqiu Guo ◽  
Bingmi Liu ◽  
Hao Pan ◽  
...  

In this study, graphene oxide was synthesized using the Hummers method, and stable and homogeneous graphene oxide aqueous solutions were obtained through mechanical stirring and ultrasonic stripping. In conjunction with our previous studies, graphene oxide-loaded insoluble compound delivery systems were prepared to verify the in vivo release profiles of the graphene oxide delivery system. Several insoluble compounds including imatinib, nilotinib, erlotinib, gefitinib, and afatinib were selected for loading and in vitro graphene oxide release assays to study the non-covalent adsorption mechanisms. Computer simulations were employed for validation processes. For in vivo release assays, the T1/2 values of the poorly water soluble groups were 1.104 ± 0.18 h and the Cmax was 2.600 ± 2.06 mg/L. In previous assays, compounds with high water solubility supported by graphene oxide were released and detected in vivo. The solubility of the compound and its binding force with the carrier played a crucial role in release. The results of graphene oxide loading experiments showed that the maximum loading and entrapment efficiencies of the insoluble model compounds with similar aromatic rings were comparable. Under basic conditions, the in vitro release rates and maximum release levels of amino pyrimidine were elevated. In contrast, quinazoline release declined. Combined with computer simulations, π–π stacking was identified as the dominant mechanism for adsorption onto graphene oxide. Both hydrogen bonding and cation-π bonds played an auxiliary reinforcing role, and the two were regarded as antagonistic.


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2560 ◽  
Author(s):  
Gökçe Şeker Karatoprak ◽  
Esra Küpeli Akkol ◽  
Yasin Genç ◽  
Hilal Bardakcı ◽  
Çiğdem Yücel ◽  
...  

Combretastatins are a class of closely related stilbenes (combretastatins A), dihydrostilbenes (combretastatins B), phenanthrenes (combretastatins C) and macrocyclic lactones (combretastatins D) found in the bark of Combretum caffrum (Eckl. & Zeyh.) Kuntze, commonly known as the South African bush willow. Some of the compounds in this series have been shown to be among the most potent antitubulin agents known. Due to their structural simplicity many analogs have also been synthesized. Combretastatin A4 phosphate is the most frequently tested compounds in preclinical and clinical trials. It is a water-soluble prodrug that the body can rapidly metabolize to combretastatin A4, which exhibits anti-tumor properties. In addition, in vitro and in vivo studies on combretastatins have determined that these compounds also have antioxidant, anti-inflammatory and antimicrobial effects. Nano-based formulations of natural or synthetic active agents such as combretastatin A4 phosphate exhibit several clear advantages, including improved low water solubility, prolonged circulation, drug targeting properties, enhanced efficiency, as well as fewer side effects. In this review, a synopsis of the recent literature exploring the combretastatins, their potential effects and nanoformulations as lead compounds in clinical applications is provided.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Gabriela P. F. Arrifano ◽  
Mathieu P. Lichtenstein ◽  
José Rogério Souza-Monteiro ◽  
Marcelo Farina ◽  
Hervé Rogez ◽  
...  

Seizures affect about 50 million people around the world. Approximately 30% of seizures are refractory to the current pharmacological arsenal, so, the pursuit of new therapeutic alternatives is essential. Clarified Euterpe oleracea (EO) juice showed anticonvulsant properties similar to diazepam in an in vivo model with pentylenetetrazol, a GABAA receptor blocker. This study investigated the effects of EO on the main GABAergic targets for anticonvulsant drugs, analyzing the effect on the GABA receptor’s benzodiazepine and picrotoxinin binding sites and the GABA uptake. Primary cultures of cortical neurons and astrocytes were treated with EO (0–25%) for up to 90 min. [3H]Flunitrazepam and [3H]TBOB binding, [3H]GABA uptake, cell viability, and morphology were assayed. Nonlethal concentrations of EO increased agonist binding and decreased antagonist binding in cortical neurons. Low concentrations significantly inhibited GABA uptake, especially in astrocytes, suggesting an accumulation of endogenous GABA in the synaptic cleft. The results demonstrate, for the first time, that EO can improve GABAergic neurotransmission via interactions with GABAA receptor and modulation of GABA uptake. Understanding these molecular mechanisms will help in the treatment of seizures and epilepsy, especially in developing countries where geographic isolation and low purchasing power are the main barriers to access to adequate treatment.


2021 ◽  
Vol 12 ◽  
Author(s):  
Marianela Evelyn Traetta ◽  
Nonthué Alejandra Uccelli ◽  
Sandra Cristina Zárate ◽  
Dante Gómez Cuautle ◽  
Alberto Javier Ramos ◽  
...  

Synaptic alterations concomitant with neuroinflammation have been described in patients and experimental models of autism spectrum disorder (ASD). However, the role of microglia and astroglia in relation to synaptic changes is poorly understood. Male Wistar rats prenatally exposed to valproic acid (VPA, 450 mg/kg, i.p.) or saline (control) at embryonic day 10.5 were used to study synapses, microglia, and astroglia in the prefrontal cortex (PFC) at postnatal days 3 and 35 (PND3 and PND35). Primary cultures of cortical neurons, microglia, and astroglia isolated from control and VPA animals were used to study each cell type individually, neuron-microglia and microglia-astroglia crosstalk. In the PFC of VPA rats, synaptic changes characterized by an increase in the number of excitatory synapses were evidenced at PND3 and persisted until PND35. At PND3, microglia and astroglia from VPA animals were morphologically similar to those of age-matched controls, whereas at PND35, reactive microgliosis and astrogliosis were observed in the PFC of VPA animals. Cortical neurons isolated from VPA rats mimicked in vitro the synaptic pattern seen in vivo. Cortical microglia and astroglia isolated from VPA animals exhibited reactive morphology, increased pro-inflammatory cytokines, and a compromised miRNA processing machinery. Microglia from VPA animals also showed resistance to a phagocytic challenge. In the presence of neurons from VPA animals, microglia isolated from VPA rats revealed a non-reactive morphology and promoted neurite outgrowth, while microglia from control animals displayed a reactive profile and promoted dendritic retraction. In microglia-astroglia co-cultures, microglia from VPA animals displayed a reactive profile and exacerbated astrocyte reactivity. Our study indicates that cortical microglia from VPA animals are insensitive or adapted to neuronal cues expressed by neurons from VPA animals. Further, long-term in vivo microgliosis could be the result of altered microglia-astroglia crosstalk in VPA animals. Thus, our study highlights cortical microglia-astroglia communication as a new mechanism implicated in neuroinflammation in ASD; consequently, we propose that this crosstalk is a potential target for interventions in this disorder.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 633
Author(s):  
Suvidha Menon ◽  
Xiuyi Liang ◽  
Richa Vartak ◽  
Ketankumar Patel ◽  
Antonio Di Stefano ◽  
...  

Carvacrol (CAR), a phenolic monoterpenoid, has been extensively investigated for its antimicrobial and antifungal activity. As a result of its poor physicochemical properties, water soluble carvacrol prodrugs (WSCPs) with improved water solubility were previously synthesized and found to possess antimicrobial activity. Here, three novel CAR analogs, WSCP1, WSCP2, and WSCP3, were tested against fluconazole (FLU)-sensitive and -resistant strains where they showed greater antifungal activity than CAR against C. albicans. The probable mechanism by which the CAR prodrugs exert the antifungal activity was studied. Results from medium acidification assays demonstrated that the CAR and its synthetically designed prodrugs inhibit the yeast plasma membrane H+-ATPase (Pma1p), an essential target in fungi. In other words, in vitro data indicated that CAR analogs can prove to be a better alternative to CAR considering their improved water solubility. In addition, CAR and WSCP1 were developed into intravaginal formulations and administered at test doses of 50 mg/kg in a mouse model of vulvovaginal candidiasis (VVC). Whereas the CAR and WSCP1 formulations both exhibited antifungal efficacy in the mouse model of VVC, the WSCP1 formulation was superior to CAR, showing a remarkable decrease in infection by ~120-fold compared to the control (infected, untreated animals). Taken together, a synthetically designed prodrug of CAR, namely WSCP1, proved to be a possible solution for poorly water-soluble drugs, an inhibitor of an essential yeast pump in vitro and an effective and promising antifungal agent in vivo.


2007 ◽  
Vol 85 (6) ◽  
pp. 621-627 ◽  
Author(s):  
Yan-Hong Li ◽  
Pei-Li Gong

We have previously reported that dauricine protects brain tissues from focal cerebral ischemia. To corroborate this effect, neurotoxicity due to hypoxia and hypoglycemia was assessed in primary cultures of rat cortical neurons by using a trypan blue exclusion method. To further clarify the mechanism, the intracellular Ca2+ concentration ([Ca2+]i) and mitochondrial membrane potential (ΔΨm) of dissociated rat cortical cells were monitored by fura-2 fluorescence measurements and flow cytometry, respectively. The results showed that 1 and 10 μmol/L dauricine significantly enhanced neuronal survival during 4 h of hypoxia and hypoglycemia. Dauricine inhibited the increase in [Ca2+]i and decrease in ΔΨm induced by 30 min of hypoxia and hypoglycemia. When exploring the pathway, we found that 1 μmol/L dauricine inhibited the [Ca2+]i increase induced by 7.5 nmol/L thapsigargin in either the presence or absence of extracellular Ca2+ and by 1 mmol/L l-glutamate in the presence of extracellular Ca2+. These results suggest that dauricine prevents neuronal loss from ischemia in vitro, which is in accordance with our previous research in vivo. In addition, by inhibiting Ca2+ release from the endoplasmic reticulum and Ca2+ influx from the extracellular space, dauricine suppressed the increase in [Ca2+]i and, subsequently, the decrease in ΔΨm induced by hypoxia and hypoglycemia. This effect may underlie the mechanism of action of dauricine on cerebral ischemia.


Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.


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