Characterization and In Vivo Antiangiogenic Activity Evaluation of Morin-Based Cyclodextrin Inclusion Complexes

Naringenin-Loaded Solid Lipid Nanoparticles: Physical-Chemical Characterization and In Vitro Antibacterial Activity

Currently, problems related to antibiotic resistance are shifting the focus of pharmaceutical research towards natural molecules with antibacterial properties. Among them, flavonoids represent promising molecules with strong antibacterial features; however, they have poor biopharmaceutical properties. In this study, we developed solid lipid nanoparticles (SLNs) loaded with the flavanone naringenin (NRG) to offer an option for treating bacterial infections. NRG-SLNs systems were prepared by a solvent emulsification/diffusion and ultrasonication method, using Compritol® 888 ATO (COM) as the lipid. The optimal formulation was obtained using a 10% (w/w) theoretical amount of NRG (NRG10-SLNs), exhibiting homogeneous sizes (approximately 50 nm and 0.15 polydispersity index), negative zeta potential (-30 mV), and excellent encapsulation parameters (an encapsulation efficiency percentage of 97.9% and a drug content of 4%). NRG10-SLNs presented good physical stability over 4 weeks. A cumulative drug release of 55% in 24 h and the prolonged release of the remaining amount over 10 days was observed. In addition, µ-Raman spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction measurements were carried out to characterize the drug-lipid interactions. Finally, the in vitro antibacterial and antibiofilm activities of NRG10-SLNs were assayed and compared to free NRG. NRG10-SLNs were bacteriostatic against Staphylococcus aureus, including the methicillin-resistant S. aureus (MRSA) and Escherichia coli strains. An improvement in the antibacterial activity of NRG-loaded SLNs compared to the free molecule was observed against S. aureus strains, probably due to the interaction of the surfactant-coated SLNs with the bacterial surface. A similar trend was observed for the biofilm inhibition.

A dissolving microneedle patch loaded with plumbagin/hydroxypropyl-β-cyclodextrin inclusion complex for infected wound healing

Treating infected wounds is facing a serious challenge due to the rapid spread of antibiotic resistance worldwide. In the search for novel antimicrobial drugs, natural products often serve as a crucial resource. Plumbagin (PLB) is the most important natural active ingredient in the root of Plumbago zeylanica L. known for its excellent antibacterial ability. However, the application of PLB is limited because of its poor water solubility, instability, and tendency to sublimate. In this study, we propose a solution by designing a hyaluronic acid (HA)/polyvinylpyrrolidone (PVP) dissolving microneedle patch loaded with PLB/hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex. PLB was encapsulated into the cavity of HP-β-CD to improve its solubility and stability using the neutralization agitation method. The formation of the inclusion complex significantly increased the water solubility of PLB to 1350 ± 6.8 μg/mL, which is 17 times higher than its original value of 79.3 ± 1.7 μg/mL. The encapsulation efficiency was found to be 94.82 ± 3.34 %. In vitro drug release studies, PLB microneedles loaded with PLB/HP-β-CD inclusion complex rapidly released into PBS within 15 min. Furthermore, the PLB microneedles exhibited strong antibacterial activity against Staphylococcus aureus (S. aureus) both in vivo and in vitro. They also remarkably accelerated the healing of infected wounds in mice by enhancing collagen deposition and re-epithelialization, reducing inflammation, and stimulating angiogenesis. Overall, this multifunctional microneedle patch shows promising potential for clinical applications in the healing of infected wounds.

Antiangiogenic potential of Elaeagnus umbellata extracts and molecular docking study by targeting VEGFR-2 pathway

Background

Anti-angiogenesis or inhibition of blood vessel formation is the best way to prevent the growth and metastasis of tumors. Natural sources like plants are currently being explored for its antiangiogenic activity as they are factories of various phytochemicals. The goal of the current study is to investigate the antiangiogenic potential of Elaeagnus umbellata (E. umbellata) by using chorioallantoic membrane (CAM) assay and molecular docking.

Methods

Based on our previous research, the antiangiogenic activity was carried out using active fractions including crude methanol (Eu-Met), ethyl acetate (Eu-EtAc), and chloroform (Eu-Chf) extracts using CAM assay. Furthermore, to understand the binding mechanism of identified compounds, molecular docking was performed against vascular endothelial growth factor receptor 2 (VEGFR-2) using AutoDock vina as docking software. VEGFR-2 is overexpressed in pathological angiogenesis.

Results

In CAM assay, Eu-Met, Eu-EtAc, and Eu-Chf extracts showed antiangiogenic activities but notable antiangiogenic activities were exhibited by Eu-Chf with IC50 value of 65.02 μg/mL. In molecular docking, five compounds, catechin, catechin hydrate, morin, quercetin, and rutin, reported in the extract and active fractions (Eu-Met, Eu-EtAc, and Eu-Chf) of E. umbellata showed strong interactions with VEGFR-2 with binding affinities of -9.4, -9.3, -9.9, -10.2, and -9.4 kcal/mol.

Conclusion

Based on our results, we can claim that E. umbellata possess antiangiogenic activity which needs to be explored further.

Randomly methylated β-cyclodextrin improves water - solubility, cellular protection and mucosa permeability of idebenone

Neurodegenerative diseases such as Alzheimer's are very common today. Idebenone (IDE) is a potent antioxidant with good potential for restoring cerebral efficiency in cases of these and other medical conditions, but a serious drawback for the clinical use of IDE in neurological disorders lies in its scarce water solubility, which greatly inhibits its bioavailability. In this work, we prepared the inclusion complex of IDE with randomly methylated β-cyclodextrin (RAMEB), resulting in improved water solubility of the included drug; then its in vitro biological activity and ex vivo permeability was evalutated. The solid complex was characterized through FT-IR spectroscopy, Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). A 78-fold improvement of the solubility of IDE in water resulted, together with a strong 1:1 host-guest interaction (association constant of 12630 M-1), and dissolution of the complex within 15 min, all evidenced during the in-solution studies. Biological in vitro studies were then performed on differentiated human neuroblastoma cells (SH-SY5Y) subjected to oxidative stress. Pretreatment with IDE/RAMEB positively affected cell viability, promoted the nuclear translocation of Nrf2, and increased the levels of GSH as well as those of the endogenous antioxidant enzymes Mn-SOD and HO-1. Lastly, the complexation significantly improved the permeation of IDE through isolated rat nasal mucosa.

Activated carbon-coated iron oxide magnetic nanocomposite (IONPs@CtAC) loaded with morin hydrate for drug-delivery applications

Cancer is a major disease that affects millions of people around the world every year. It affects individuals of all ages, races, and backgrounds. Since drugs used to treat cancer cannot distinguish between cancerous and healthy cells, they cause systemic toxicity along with serious side effects. Recently, controlled drug-release systems have been developed to reduce the side effects caused by anticancer drugs used for treatment. Morin is an anticancer drug with a flavonol structure. It has been extensively researched for its antioxidant, anti-inflammatory, antitumoral, and antibacterial properties, especially found in Chinese herbs and fruits, and its multiple positive effects on different diseases. In this study, a nanocomposite with magnetic properties was synthesized by coating biocompatible activated carbon obtained using the fruits of the Celtis tournefortii plant on the surface of iron oxide magnetic nanoparticles. Characterization of the synthesized activated carbon-coated iron oxide magnetic nanocomposite was confirmed by Fourier transform infrared, scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffraction, dynamic light scattering, zeta potential, and vibrating sample magnetometry. The cytotoxic effects of the drug-loaded magnetic nanocomposite were examined in HT-29 (colorectal), T98-G (glioblastoma) cancer cell lines, and human umbilical vein endothelial cell (HUVEC) healthy cell line. The morin loading and release behavior of the activated carbon-coated iron oxide magnetic nanocomposite were studied, and the results showed that up to 60% of the adsorbed morin was released within 4 h. In summary, activated carbon-coated iron oxide magnetic nanocomposite carriers have shown promising results for the delivery of the morin drug.

Rutin/Sulfobutylether-β-Cyclodextrin as a Promising Therapeutic Formulation for Ocular Infection

Ocular pathologies present significant challenges to achieving effective therapeutic results due to various anatomical and physiological barriers. Natural products such as flavonoids, alone or in association with allopathic drugs, present many therapeutic actions including anticancer, anti-inflammatory, and antibacterial action. However, their clinical employment is challenging for scientists due to their low water solubility. In this study, we designed a liquid formulation based on rutin/sulfobutylether-β-cyclodextrin (RTN/SBE-β-CD) inclusion complex for treating ocular infections. The correct stoichiometry and the accurate binding constant were determined by employing SupraFit software (2.5.120) in the UV-vis titration experiment. A deep physical-chemical characterization of the RTN/SBE-β-CD inclusion complex was also performed; it confirmed the predominant formation of a stable complex (Kc, 9660 M-1) in a 1:1 molar ratio, with high water solubility that was 20 times (2.5 mg/mL) higher than the free molecule (0.125 mg/mL), permitting the dissolution of the solid complex within 30 min. NMR studies revealed the involvement of the bicyclic flavonoid moiety in the complexation, which was also confirmed by molecular modeling studies. In vitro, the antibacterial and antibiofilm activity of the formulation was assayed against Staphylococcus aureus and Pseudomonas aeruginosa strains. The results demonstrated a significant activity of the formulation than that of the free molecules.

Comparative Investigation into the Roles of Imipenem:Cyclodextrin Complexation and Antibiotic Combination in Combatting Antimicrobial Resistance in Gram-Negative Bacteria

Extensively drug-resistant (XDR), multidrug-resistant (MDR) and pandrug-resistant (PDR) Gram-negative microorganisms (GNBs) are considered a significant global threat. β-lactam and aminoglycoside combinations and imipenem:cyclodextrin inclusion complexes were studied for the treatment of lethal GNBs. This is because of the broad empiric coverage of the two drugs and their possession of different spectra of activity. Two cyclodextrins (β- and hydroxy propyl β-cyclodextrins) were utilized for inclusion complex formation with imipenem using the physical and kneading methods. In silico investigation using the molecular docking and Fourier-infrared spectroscopy (FTIR) were employed to estimate binding constant and confirm complex formation, respectively. The in vitro effects of amikacin and imipenem combination in comparison to the effect of imipenem-β- and hydroxy propyl β-cyclodextrin (CD) complexes against Klebsiella spp. and Acinetobacter baumannii were studied. The isolated microorganisms' antimicrobial responsiveness to various antibiotics (19 antibiotics) was evaluated. It was found that piperacillin/tazobactam and gentamycin (resistance rates were 33.3% and 34%, respectively) were the most effective antimicrobials. The in vitro studies have been performed by the checkerboard technique and time-killing assay. The studied combination of amikacin and imipenem showed a substantial drop in bacterial count (p < 0.05). The in vitro studies demonstrated a synergism for the investigated combination. Conventional PCR was used in molecular studies to identify the resistance genes bla IMP and aac (6')-Ib. The blaIMP and aac (6')-Ib were recorded in 38.2% and 3.6% of the studied isolates, respectively. The in vitro studies showed synergistic effects among the tested antibiotics with FICIs of ≤0.5. Finally, the study compared the reduction in bacterial count between the tested antibiotic combinations and imipenem:CD physical and kneaded mixtures. Imipenem:CD inclusion complexes demonstrated a significant bacterial count reduction over the antibiotic combination. These results highlight the emerging role of CDs as safe biofunctional excipients in the combat against superbug bacterial resistance.

Anti-Neurodegenerating Activity: Structure-Activity Relationship Analysis of Flavonoids

An anti-neurodegeneration activity study was carried out for 80 flavonoid compounds. The structure-activity analysis of the structures was carried out by performing three different anti-neurodegeneration screening tests, showing that in these structures, the presence of a hydroxy substituent group at position C3' as well as C5' of ring B and a methoxy substituent group at the C7 position of ring A play a vital role in neuroprotective and antioxidant as well as anti-inflammatory activity. Further, we found structure (5) was the top-performing active structure out of 80 structures. Subsequently, a molecular docking study was carried out for the 3 lead flavonoid compounds (4), (5), and (23) and 21 similar hypothetical proposed structures to estimate the binding strength between the tested compounds and proteins potentially involved in disease causation. Ligand-based pharmacophores were generated to guide future drug design studies.