Oleuropein as a Potent Compound against Neurological Complications Linked with COVID-19: A Computational Biology Approach.

The association of COVID-19 with neurological complications is a well-known fact, and researchers are endeavoring to investigate the mechanistic perspectives behind it. SARS-CoV-2 can bind to Toll-like receptor 4 (TLR-4) that would eventually lead to α-synuclein aggregation in neurons and stimulation of neurodegeneration pathways. Olive leaves have been reported as a promising phytotherapy or co-therapy against COVID-19, and oleuropein is one of the major active components of olive leaves. In the current study, oleuropein was investigated against SARS-CoV-2 target (main protease 3CLpro), TLR-4 and Prolyl Oligopeptidases (POP), to explore oleuropein potency against the neurological complications associated with COVID-19. Docking experiments, docking validation, interaction analysis, and molecular dynamic simulation analysis were performed to provide insight into the binding pattern of oleuropein with the three target proteins. Interaction analysis revealed strong bonding between oleuropein and the active site amino acid residues of the target proteins. Results were further compared with positive control lopinavir (3CLpro), resatorvid (TLR-4), and berberine (POP). Moreover, molecular dynamic simulation was performed using YASARA structure tool, and AMBER14 force field was applied to examine an 100 ns trajectory run. For each target protein-oleuropein complex, RMSD, RoG, and total potential energy were estimated, and 400 snapshots were obtained after each 250 ps. Docking analyses showed binding energy as -7.8, -8.3, and -8.5 kcal/mol for oleuropein-3CLpro, oleuropein-TLR4, and oleuropein-POP interactions, respectively. Importantly, target protein-oleuropein complexes were stable during the 100 ns simulation run. However, an experimental in vitro study of the binding of oleuropein to the purified targets would be necessary to confirm the present study outcomes.

Brucine-Loaded Ethosomal Gel: Design, Optimization, and Anti-inflammatory Activity.

Brucine, one of the natural medications obtained from Nux vomica seeds, is used as an anti-inflammatory drug. Several investigations were performed to overcome its drawbacks, which will affect significantly its pharmaceutical formulation. The goal of the current investigation was to design, optimize, and evaluate the anti-inflammatory performance of BRU ethosomal gel. Brucineethosomal formulations were prepared using thin film hydration method and optimized by central composite design approach using three independent variables (lecithin concentration, cholesterol concentration, and ethanol percentage) and three response variables (vesicular size, encapsulation efficiency, and skin permeation). The optimized formulation was examined for its stability and then incorporated into HPMC gel to get BRU ethosomal gel. The obtained BRU-loaded ethosomal gel was evaluated for its physical properties, in vitro release, and ex vivo permeation and skin irritation. Finally, carrageenan-induced rat hind paw edema test was adopted for the anti-inflammatory activity. The developed BRU ethosomal gel exhibited good physical characteristics comparable with the conventional developed BRU gel. In vitro release of BRU from ethosomal gel was effectively extended for 6 h. Permeation of BRU from ethosomes was significantly higher than all formulations (p < 0.05), since it recorded steady state transdermal flux value 0.548 ± 0.03 µg/cm2 h with enhancement ratio 2.73 ± 0.23. Eventually, BRU ethosomal gel exhibited potent anti-inflammatory activity as manifested by a significant decrease in rat hind paw inflammation following 24 h. In conclusion, the study emphasized the prospective of ethosomal gel as a fortunate carrier for intensifying the anti-inflammatory effect of Brucine.

Achillea fragrantissima (Forssk.) Sch.Bip. methanolic extract exerts potent antimicrobial activity and causes cancer cell death via induction of caspase-dependent apoptosis and S-phase arrest.

This study was done to evaluate the anticancer potential of Achillea fragrantissima (Forssk.) Sch.Bip. leaves methanolic extract in detail for the first time, in addition to investigating its antimicrobial activity. The antimicrobial assay revealed that the extract exerted high activity against P. vulgaris (MIC = 156.25 µg/ml) and C. albicans (MIC = 625 µg/ml), while moderate activity was observed against other microbes. The extract was also screened against HepG2, A549, HCT116 and MCF7 cancer cells and was found to be active across all cells with highest selectivity and cytotoxic activity being observed for A549 cells (IC50 = 1.21 µg/ml). Further mechanistic studies on A549 cells showed that the extract resulted in S-phase arrest and induced apoptosis via activation of caspase-3, p53 and Bax, in addition to downregulation of Bcl-2. HR-LCMS analysis indicated the presence of 3-hydroxycoumarin, quercetin 3,3'-dimethyl ether and skullcapflavone II which might be responsible for the extract's bioactivity.

Dithymoquinone Analogues as Potential Candidate(s) for Neurological Manifestation Associated with COVID-19: A Therapeutic Strategy for Neuro-COVID.

The COVID-19 era has prompted several researchers to search for a linkage between COVID-19 and its associated neurological manifestation. Toll-like receptor 4 (TLR-4) acts as one such connecting link. spike protein of SARS-CoV-2 can bind either to ACE-2 receptors or to TLR-4 receptors, leading to aggregation of α-synuclein and neurodegeneration via the activation of various cascades in neurons. Recently, dithymoquinone has been reported as a potent multi-targeting candidate against SARS-CoV-2. Thus, in the present study, dithymoquinone and its six analogues were explored to target 3CLpro (main protease of SARS-CoV-2), TLR4 and PREP (Prolyl Oligopeptidases) by using the molecular docking and dynamics approach. Dithymoquinone (DTQ) analogues were designed in order to investigate the effect of different chemical groups on its bioactivity. It is noteworthy to mention that attention was given to the feasibility of synthesizing these analogues by a simple photo-dimerisation reaction. The DTQ analogue containing the 4-fluoroaniline moiety [Compound (4)] was selected for further analysis by molecular dynamics after screening via docking-interaction analyses. A YASARA structure tool built on the AMBER14 force field was used to analyze the 100 ns trajectory by taking 400 snapshots after every 250 ps. Moreover, RMSD, RoG, potential energy plots were successfully obtained for each interaction. Molecular docking results indicated strong interaction of compound (4) with 3CLpro, TLR4 and PREP with a binding energy of -8.5 kcal/mol, -10.8 kcal/mol and -9.5 kcal/mol, respectively, which is better than other DTQ-analogues and control compounds. In addition, compound (4) did not violate Lipinski's rule and showed no toxicity. Moreover, molecular dynamic analyses revealed that the complex of compound (4) with target proteins was stable during the 100 ns trajectory. Overall, the results predicted that compound (4) could be developed into a potent anti-COVID agent with the ability to mitigate neurological manifestations associated with COVID-19.

Quality by Design for Optimizing a Novel Liposomal Jojoba Oil-Based Emulgel to Ameliorate the Anti-Inflammatory Effect of Brucine.

One of the recent advancements in research is the application of natural products in developing newly effective formulations that have few drawbacks and that boost therapeutic effects. The goal of the current exploration is to investigate the effect of jojoba oil in augmenting the anti-inflammatory effect of Brucine natural alkaloid. This is first development of a formulation that applies Brucine and jojoba oil int a PEGylated liposomal emulgel proposed for topical application. Initially, various PEGylated Brucine liposomal formulations were fabricated using a thin-film hydration method. (22) Factorial design was assembled using two factors (egg Phosphatidylcholine and cholesterol concentrations) and three responses (particle size, encapsulation efficiency and in vitro release). The optimized formula was incorporated within jojoba oil emulgel. The PEGylated liposomal emulgel was inspected for its characteristics, in vitro, ex vivo and anti-inflammatory behaviors. Liposomal emulgel showed a pH of 6.63, a spreadability of 48.8 mm and a viscosity of 9310 cP. As much as 40.57% of Brucine was released after 6 h, and drug permeability exhibited a flux of 0.47 µg/cm2·h. Lastly, % of inflammation was lowered to 47.7, which was significant effect compared to other formulations. In conclusion, the anti-inflammatory influence of jojoba oil and Brucine was confirmed, supporting their integration into liposomal emulgel as a potential nanocarrier.

Preparation, characterization and evaluation of anti-inflammatory and anti-nociceptive effects of brucine-loaded nanoemulgel.

Brucine (BRU) is a natural product derived from nux-vomica seeds. It is commonly used as an anti-inflammatory and anti-nociceptive drug to relieve arthritis and traumatic pain. Nevertheless, its use is significantly limited by its low aqueous solubility, as well as the gastrointestinal problems and systemic toxicity that may occur following oral administration. The goal of this study, therefore, was to formulate and evaluate a nanoemulgel formulation of BRU for enhanced topical anti-inflammatory and anti-nociceptive activities. Different formulations were developed (BRU gel, emulgel and nanoemulgel) using 1% w/w NaCMC as a gelling agent. The formulated preparations were assessed for their physical appearance, spreadability, viscosity, particle size, in vitro drug release and ex vivo permeation studies. In addition, the carrageenan-induced rat hind paw edema method was adopted to scrutinize the anti-inflammatory activity, while the hot plate method and acetic acid-induced writhing test were used to assess the anti-nociceptive activity of different formulations in male BALB/c mice. The formulated BRU-loaded preparations showed good physical characteristics. Cumulative drug release from BRU-loaded nanoemulgel was remarkably higher than that of the other formulations. Ex vivo drug permeation of the nanoemulgel formulation across rat skin showed enhanced drug permeation and higher transdermal flux as compared to BRU-loaded gel or emulgel. Most importantly, the carrageenan-induced rat hind paw edema model verified the efficient anti-inflammatory potential of BRU-loaded nanoemulgel. In addition, BRU-loaded nanoemulgel exhibited significant protective effects against thermal stimulation in the hot plate test and remarkably inhibited acetic acid-induced abdominal writhing in mice. Furthermore, a skin irritation test indicated that BRU-loaded nanoemulgel elicited neither edema nor erythema upon application to rat skin. Collectively, our results suggest that myrrh oil-based nanoemulgel might represent a promising delivery vehicle for potentiating the anti-inflammatory and anti-nociceptive actions of brucine.