Liposomal Formulation to Increase Stability and Prolong Antineuropathic Activity of Verbascoside

Verbascoside: comprehensive review of a phenylethanoid macromolecule and its journey from nature to bench

Polyphenolic compounds are among the most widely researched compounds for various therapeutic applications. However, naturally occurring phenylethanoid glycosides are least explored under this class of compounds. One such phenylethanoid glycoside, verbascoside (Vb), abundantly found among 200 species of 23 families, has gained recent attention due to its wide-spectrum therapeutic properties such as antioxidant, antimicrobial, anti-inflammatory, neuroprotective, cardioprotective, skin-protective, and anti-cancer. Despite having multiple therapeutic benefits, due to its large size, the compound has poor bioavailability for oral and topical applications. To meet these limitations, current research on Vb focuses on delivering it through nanoformulations. Presently, most developed formulations are liposome based for various applications, such as corneal epithelial wound healing, anti-neuropathic, anti-wrinkle, anti-hyperalgesia, atopic dermatitis, alopecia, and cutaneous wound healing. Multiple studies have confirmed the least acute and sub-acute toxicity for Vb. Few clinical studies have been performed for the therapeutic application of Vb to manage COVID-19, nephropathy, platelet aggregation, chronic primary glomerulonephritis, and acute hepatitis. Recent studies have shown the immense therapeutic potential of Vb in wound healing, dermatitis, neuroprotection, and anti-cancer activities, which creates a need for developing novel formulations for their respective uses. Long-term toxicity studies and techniques for scaling up Vb production by biotechnological approaches should be emphasized.

Bile salt-enriched vs. non-enriched nanoparticles: comparison of their physicochemical characteristics and release pattern

Bile salts were first used in the preparation of nanoparticles due to their stabilizing effects. As time went by, they attracted much attention and were increasingly employed in fabricating nanoparticles. It is well accepted that the physicochemical properties of nanoparticles are influential factors in their permeation, distribution, elimination and degree of effectiveness as well as toxicity. The review of articles shows that the use of bile salts in the structure of nanocarriers may cause significant changes in their physicochemical properties. Hence, having information about the effect of bile salts on the properties of nanoparticles could be valuable in the design of optimal carriers. Herein, we review studies in which bile salts were used in preparing liposomes, niosomes and other nanocarriers. Furthermore, the effects of bile salts on entrapment efficiency, particle size, polydispersity index, zeta potential, release profile and stability of nanoparticles are pointed out. Finally, we debate how to take advantage of bile salts potential for preparing desirable nanocarriers.

Lipid-based nanocarriers for enhanced delivery of plant-derived bioactive molecules: a comprehensive review

Bioactive compounds derived from plants have been investigated for treating various pathological conditions. However, the utilization of these compounds has challenges such as instability, low solubility and bioavailability. To overcome these challenges, the encapsulation of bioactive molecules with in a novel nano carrier system enabling effective delivery and clinical translation has become essential. Lipid-based nanocarriers provide versatile platforms for encapsulating and delivering bioactive compounds and overcome the challenges. These novel carriers can improve solubility, stability, improved drug retention and therapeutic efficacy of plant derived bioactive compounds. The current review evaluates the challenges in delivery of plant bioactives and highlights the potential of various lipid-based nano carriers designed to improve its therapeutic efficacy.

From Plant to Chemistry: Sources of Active Opioid Antinociceptive Principles for Medicinal Chemistry and Drug Design

Pain continues to be an enormous global health challenge, with millions of new untreated or inadequately treated patients reported annually. With respect to current clinical applications, opioids remain the mainstay for the treatment of pain, although they are often associated with serious side effects. To optimize their tolerability profiles, medicinal chemistry continues to study novel ligands and innovative approaches. Among them, natural products are known to be a rich source of lead compounds for drug discovery, and they hold potential for pain management. Traditional medicine has had a long history in clinical practice due to the fact that nature provides a rich source of active principles. For instance, opium had been used for pain management until the 19th century when its individual components, such as morphine, were purified and identified. In this review article, we conducted a literature survey aimed at identifying natural products interacting either directly with opioid receptors or indirectly through other mechanisms controlling opioid receptor signaling, whose structures could be interesting from a drug design perspective.

PEGylated liposomes enhance the effect of cytotoxic drug: A review

Cancer is a second leading disease-causing death worldwide that will continuously grow as much as 70% in the next 20 years. Chemotherapy is still becoming a choice for cancer treatment despite its severity of side effects and low success rate due to ineffective delivery of the chemodrugs. Since it was introduced in 1960, significant progress has been achieved in the use of liposomes in drug delivery. The study aims to review relevant literatures on role of PEGylated liposome in enhancing cytotoxic activity of several agents. A systematic literature on the use of PEGylated liposomes in anticancer research via Scopus, Google scholar and PubMed databases was conducted for studies published from 2000 to 2022. A total of 15 articles were selected and reviewed from 312 articles identified covering a variety of anticancer treatments by using PEGylated liposomes. PEGylated liposome which is purposed to achieve steric equilibrium is one of enhanced strategies to deliver anticancer drugs. It has been shown that some improvement of delivery and protection form a harsh gastric environment of several anticancer drugs when they are formulated in a PEGylated liposome. One of the successful drugs that has been clinically used is Doxil®, followed by some other drugs in the pipeline Various drugs (compounds) had been used to enhance the efficacy of PEGylated liposomes for targeted cancer cells in vitro and in vivo. In conclusion, PEGylated liposomes enhance drug activities and have great potential to become efficient anticancer delivery to follow Doxil® in the clinical setting.

Microglia senescence is related to neuropathic pain-associated comorbidities in the spared nerve injury model

ABSTRACT

The increased presence of senescent cells in different neurological diseases suggests the contribution of senescence in the pathophysiology of neurodegenerative disorders. Microglia can adapt to any type of disturbance of the homeostasis of the central nervous system (CNS) and its altered activity can lead to permanent and unresolvable damage. The aim of this work was to characterize the behavioural phenotype of spared nerve injury (SNI) mice and then associate it to senescence-related mechanisms. In this work we investigated the timing of the onset of anxiety, depression, or memory decline associated with peripheral neuropathic pain, and their correlation with the presence of microglial cellular senescence. SNI mice showed a persistent pain hypersensitivity from 3 days after surgery. 28 days after nerve injury they also developed anxiety, depression, and cognitive impairment. The appearance of these symptoms was coincident to a significant increase of senescence markers, such as β-galactosidase and senescent-associated secretory phenotype (SASP), at microglial level in the spinal cord and hippocampus of SNI animals. These markers were unaltered at previous time points. In murine immortalized microglial cells (BV2) stimulated with LPS 500 ng/mL for 10 days (4h/day) every other day, we observed an increase of β-galactosidase, SASP appearance, a reduction of cell viability and an increase of Senescence-Associated Heterochromatic Foci (SAHF). Therefore, present findings could represent an important step to a better understanding of the pathophysiological cellular mechanisms in comorbidities related to neuropathic pain states.

Research Progress and Trends of Phenylethanoid Glycoside Delivery Systems

Background: Phenylethanoid glycosides (PhGs) are obtained from a wide range of sources and show strong biological and pharmacological activities, such as antioxidant, antibacterial and neuroprotective effects. However, intestinal malabsorption and the low bioavailability of PhGs seriously affect their application. Delivery systems are an effective method to improve the bioavailability of active substances. Scope and approach: In this article, the biological activities of and delivery systems for PhGs are introduced. The application statuses of delivery systems for echinacoside, acteoside and salidroside are reviewed. Finally, the problems of the lack of uniform standards for delivery systems and the poor targeted delivery accuracy of PhGs in the current research are proposed and suggestions for future research are put forward based on those problems. Key findings and conclusions: Although there are still some problems in the delivery system of phenylethanoside, such as inconsistent standards and inaccurate delivery, phenylethanoside itself has been proven to have a variety of physiological activities. Therefore, the action mechanism and application of phenylethanoside and its delivery system should be studied further.

New Nanocarrier System for Liposomes Coated with Lactobacillus acidophilus S-Layer Protein to Improve Leu-Gln-Pro-Glu Absorption through the Intestinal Epithelium

The present study describes the development of a novel liposome nanocarrier system. The liposome was coated with Lactobacillus acidophilus CICC 6074 S-layer protein (SLP) to improve the intestinal absorption of the cholesterol-lowering peptide Leu-Gln-Pro-Glu (LQPE). The SLP-coated liposomes were prepared and characterized with morphology, particle size, zeta potential, membrane stability, Fourier transform infrared spectroscopy, and dual-channel surface plasma resonance. The results showed that SLP could successfully self-assemble on liposomes. Then, LQPE liposomes and SLP-coated LQPE liposomes (SLP-L-LQPE) were prepared. SLP-L-LQPE not only showed better sustained release properties and gastrointestinal tolerance in vitro but also increased the retention time in mice intestine. Transepithelial transport experiment indicates that the transshipment of LQPE increased significantly after being embedded by liposomes and coated with SLP. The research provides a theoretical basis for the study of SLP-coated liposomes and a potential drug delivery system for improving the intestinal absorption of peptides.

Innovative Delivery Systems Loaded with Plant Bioactive Ingredients: Formulation Approaches and Applications

Plants constitute a rich source of diverse classes of valuable phytochemicals (e.g., phenolic acids, flavonoids, carotenoids, alkaloids) with proven biological activity (e.g., antioxidant, anti-inflammatory, antimicrobial, etc.). However, factors such as low stability, poor solubility and bioavailability limit their food, cosmetics and pharmaceutical applications. In this regard, a wide range of delivery systems have been developed to increase the stability of plant-derived bioactive compounds upon processing, storage or under gastrointestinal digestion conditions, to enhance their solubility, to mask undesirable flavors as well as to efficiently deliver them to the target tissues where they can exert their biological activity and promote human health. In the present review, the latest advances regarding the design of innovative delivery systems for pure plant bioactive compounds, extracts or essential oils, in order to overcome the above-mentioned challenges, are presented. Moreover, a broad spectrum of applications along with future trends are critically discussed.

Formulation of Novel Liquid Crystal (LC) Formulations with Skin-Permeation-Enhancing Abilities of Plantago lanceolata (PL) Extract and Their Assessment on HaCaT Cells

Exposure to reactive oxygen species can easily result in serious diseases, such as hyperproliferative skin disorders or skin cancer. Herbal extracts are widely used as antioxidant sources in different compositions. The importance of antioxidant therapy in inflammatory conditions has increased. Innovative formulations can be used to improve the effects of these phytopharmacons. The bioactive compounds of Plantago lanceolata (PL) possess different effects, such as anti-inflammatory, antioxidant, and bactericidal pharmacological effects. The objective of this study was to formulate novel liquid crystal (LC) compositions to protect Plantago lanceolata extract from hydrolysis and to improve its effect. Since safety is an important aspect of pharmaceutical formulations, the biological properties of applied excipients and blends were evaluated using assorted in vitro methods on HaCaT cells. According to the antecedent toxicity screening evaluation, three surfactants were selected (Gelucire 44/14, Labrasol, and Lauroglycol 90) for the formulation. The dissolution rate of PL from the PL-LC systems was evaluated using a Franz diffusion chamber apparatus. The antioxidant properties of the PL-LC systems were evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and malondialdehyde (MDA) assessments. Our results suggest that these compositions use a nontraditional, rapid-permeation pathway for the delivery of drugs, as the applied penetration enhancers reversibly alter the barrier properties of the outer stratum corneum. These excipients can be safe and highly tolerable thus, they could improve the patient’s experience and promote adherence.

Photoprotective Activity of Buddleja cordata Cell Culture Methanolic Extract on UVB-irradiated 3T3-Swiss Albino Fibroblasts

The research on compounds exhibiting photoprotection against ultraviolet radiation (UVR) is a matter of increasing interest. The methanolic extract of a cell culture of Buddleja cordata has potential photoprotective effects as these cells produce phenolic secondary metabolites (SMs). These metabolites are attributed with biological activities capable of counteracting the harmful effects caused by UVR on skin. In the present work, the methanolic extract (310–2500 µg/mL) of B. cordata cell culture showed a photoprotective effect on UVB-irradiated 3T3-Swiss albino fibroblasts with a significant increase in cell viability. The greatest photoprotective effect (75%) of the extract was observed at 2500 µg/mL, which was statistically comparable with that of 250 µg/mL verbascoside, used as positive control. In addition, concentrations of the extract higher than 2500 µg/mL resulted in decreased cell viability (≤83%) after 24 h of exposure. Phytochemical analysis of the extract allowed us to determine that it was characterized by high concentrations of total phenol and total phenolic acid contents (138 ± 4.7 mg gallic acid equivalents and 44.01 ± 1.33 mg verbascoside equivalents per gram of extract, respectively) as well as absorption of UV light (first and second bands peaking at 294 and 330 nm, respectively). Some phenylethanoid glycosides were identified from the extract.

Preparation, Characterization, and In Vitro Pharmacodynamics and Pharmacokinetics Evaluation of PEGylated Urolithin A Liposomes

Urolithin A (Uro-A), a metabolite of ellagitannins in mammals' intestinal tract, displays broad biological properties in preclinical models, including anti-oxidant, anti-inflammatory, and anti-tumor effects. However, the clinical application of Uro-A is restricted because of its low aqueous solubility and short elimination half-life. Our purpose was to develop a delivery system to improve the bioavailability and anti-tumor efficacy of Uro-A. To achieve this goal, urolithin A-loaded PEGylated liposomes (Uro-A-PEG-LPs) were prepared for the first time and its physicochemical properties and anti-tumor efficacy in vitro were evaluated. The morphology of Uro-A-PEG-LPs displayed a uniform sphere under transmission electron microscope. The particle size, polydispersity index, zeta potential, and encapsulation efficiency of Uro-A-PEG-LPs were 122.8 ± 7.4 nm, 0.25 ± 0.16, - 25.5 ± 2.3 mV, and 94.6 ± 1.6%, respectively. Moreover, Uro-A-PEG-LPs possessed higher stability and could be stably stored at 4°C for a long time. In vitro release characteristics indicated that Uro-A-PEG-LPs possessed superior sustained release properties. The results of confocal laser scanning microscopy experiment showed that the coumarin 6-loaded PEGylated liposomes (C6-PEG-LPs) have superior cellular uptake than that of conventional liposomes. In addition, in vitro tests demonstrated that Uro-A-PEG-LPs elevated cytotoxicity and pro-apoptotic effect in human hepatoma cells comparing with free Uro-A. Furthermore, the results of pharmacokinetic experiments showed that the t_1/2, AUC_0-t, and MRT_0-t of Uro-A-PEG-LPs increased to 4.58-fold, 2.33-fold, and 2.43-fold than those of free Uro-A solution, respectively. Collectively, these manifested that PEGylated liposomes might be a potential delivery system for Uro-A to prolonging in vivo circulation time, promoting cellular uptake, and enhancing its anti-tumor efficacy.

Scope and Applications of Nanomedicines for the Management of Neuropathic Pain

Neuropathic pain, resulting from the dysfunction of the peripheral and central nervous system, occurs in a variety of pathological conditions including trauma, diabetes, cancer, HIV, surgery, multiple sclerosis, ischemic attack, alcoholism, spinal cord damage, and many others. Despite the availability of various treatment strategies, the percentage of patients achieving adequate pain relief remains low. The clinical failure of most effective drugs is often not due to a lack of drug efficacy but due to the dose-limiting central nervous system (CNS) toxicity of the drugs that preclude dose escalation. There is a need for cross-disciplinary collaborations to meet these challenges. In this regard, the integration of nanotechnology with neuroscience is one of the most important fields. In recent years, promising preclinical research has been reported in this field. This review highlights the current challenges associated with conventional neuropathic pain treatments, the scope for nanomaterials in delivering drugs across the blood-brain barrier, and the state and prospects of nanomaterials for the management of neuropathic pain.

Verbascoside inhibits progression of glioblastoma cells by promoting Let-7g-5p and down-regulating HMGA2 via Wnt/beta-catenin signalling blockade

Glioblastoma (GBM) continues to show a poor prognosis despite advances in diagnostic and therapeutic approaches. The discovery of reliable prognostic indicators may significantly improve treatment outcome of GBM. In this study, we aimed to explore the function of verbascoside (VB) in GBM and its effects on GBM cell biological processes via let‐7g‐5p and HMGA2. Differentially expressed GBM‐related microRNAs (miRNAs) were initially screened. Different concentrations of VB were applied to U87 and U251 GBM cells, and 50 µmol/L of VB was selected for subsequent experiments. Cells were transfected with let‐7g‐5p inhibitor or mimic, and overexpression of HMGA2 or siRNA against HMGA2 was induced, followed by treatment with VB. The regulatory relationships between VB, let‐7g‐5p, HMGA2 and Wnt/β‐catenin signalling pathway were determined. The results showed that HMGA2 was a direct target gene of let‐7g‐5p. VB treatment or let‐7g‐5p overexpression inhibited HMGA2 expression and the activation of Wnt/β‐catenin signalling pathway, which further inhibited cell viability, invasion, migration, tumour growth and promoted GBM cell apoptosis and autophagy. On the contrary, HMGA2 overexpression promoted cell viability, invasion, migration, tumour growth while inhibiting GBM cell apoptosis and autophagy. We demonstrated that VB inhibits cell viability and promotes cell autophagy in GBM cells by up‐regulating let‐7g‐5p and down‐regulating HMGA2 via Wnt/β‐catenin signalling blockade.

Development and Percutaneous Permeation Study of Escinosomes, Escin-Based Nanovesicles Loaded with Berberine Chloride

Escin is a natural saponin, clinically used for the anti-edematous and anti-inflammatory effects. The aim of the study was to explore the possibility of converting escin into vesicle bilayer-forming component. The hyaluronidase inhibition activity of escin was evaluated after its formulation in escinosomes. Berberine chloride, a natural quaternary isoquinoline alkaloid isolated from several medicinal plants that is traditionally used for various skin conditions was loaded in the vesicles. The developed nanovesicles were characterized in terms of diameter, polydispersity, ζ-potential, deformability, recovery, encapsulation efficiency, stability, and release kinetics. Nanovesicle permeation properties through artificial membranes and rabbit ear skin were investigated using skin-PAMPA^TM and Franz cells were also evaluated. Escinosomes, made of phosphatidylcholine and escin, were loaded with berberine chloride. These nanovesicles displayed the best characteristics for skin application, particularly optimal polydispersity (0.17) and deformability, high negative ζ-potential value, great encapsulation efficiency (about 67%), high stability, and the best release properties of berberine chloride (about 75% after 24 h). In conclusion, escinosomes seem to be new vesicular carriers, capable to maintain escin properties such as hyaluronidase inhibition activity, and able to load other active molecules such as berberine chloride, in order to enhance or expand the activity of the loaded drug.

ES2 as a Novel Verbascoside-Derived Compound in the Treatment of Cutaneous Wound Healing

Several pathologies are characterized by chronic wounds and often resistant to many of the common therapies, leading to chronic infections that can become even life-threatening for patients. For this reason, the identification of new products able to ameliorate the healing process is still an on-going research. Natural compounds have been used to improve skin conditions due to their dermo-cosmetic and therapeutic activities including anti-inflammatory, antioxidant and cell-migratory properties. Among these compounds, it has been recently demonstrated that Verbascoside, a phenyl propanoid glycoside widely used in the cosmetic field, can improve keratinocytes proliferation. Because of its high hydrophilic character, Verbascoside has a limited range of possible topical applications and the synthesis of ES2, a semi-synthetic derivative of Verbascoside was performed to bypass some of the drawback aspects of this molecule. In the present study, the wound healing properties of Verbascoside and ES2 were compared in both keratinocytes “in vitro” wound scratch and in wounded SKH1 mice. The results showed that both compounds were not cytotoxic and ES2 showed an efficient ability to promote the proliferation of human keratinocytes compared to Verbascoside. The findings were also confirmed in vivo but only at early time points (2/3 days). Taken together, these data suggest that the Verbascoside-derivative ES2 could be considered a novel and promising candidate for the topical treatment of wounds.

Nanoemulsion for improving solubility and permeability of Vitex agnus-castus extract: formulation and in vitro evaluation using PAMPA and Caco-2 approaches

The purpose of this study was to develop new formulation for an improved oral delivery of Vitex agnus-castus (VAC) extract. After the optimization and validation of analytical method for quali-quantitative characterization of extract, nanoemulsion (NE) was selected as lipid-based nanocarrier. The composition of extract-loaded NE resulted in triacetin as oil phase, labrasol as surfactant, cremophor EL as co-surfactant and water. NE contains until 60 mg/mL of extract. It was characterized by DLS and TEM analyses and its droplets appear dark with an average diameter of 11.82 ± 0.125 nm and a polydispersity index (PdI) of 0.117 ± 0.019. The aqueous solubility of the extract was improved about 10 times: the extract is completely soluble in the NE at the concentration of 60 mg/mL, while its solubility in water results less than 6 mg. The passive intestinal permeation was tested by using parallel artificial membrane permeation assay (PAMPA) and the permeation across Caco-2 cells after preliminary cytotoxicity studies were also evaluated. NE shows a good solubilizing effect of the constituents of the extract, compared with aqueous solution. The total amount of constituents permeated from NE to acceptor compartment is greater than that permeated from saturated aqueous solution. Caco-2 test confirmed PAMPA results and they revealed that NE was successful in increasing the permeation of VAC extract. This formulation could improve oral bioavailability of extract due to enhanced solubility and permeability of phytocomplex.

Self-Nanoemulsifying Drug Delivery Systems Containing Plantago lanceolata-An Assessment of Their Antioxidant and Antiinflammatory Effects

The most important components of Plantago lanceolata L. leaves are catalpol, aucubin, and acteoside (=verbascoside). These bioactive compounds possess different pharmacological effects: anti-inflammatory, antioxidant, antineoplastic, and hepatoprotective. The aim of this study was to protect Plantago lanceolata extract from hydrolysis and to improve its antioxidant effect using self-nano-emulsifying drug delivery systems (SNEDDS). Eight SNEDDS compositions were prepared, and their physical properties, in vitro cytotoxicity, and in vivo AST/ALT values were investigated. MTT cell viability assay was performed on Caco-2 cells. The well-diluted samples (200 to 1000-fold dilutions) proved to be non-cytotoxic. The acute administration of PL-SNEDDS compositions resulted in minor changes in hepatic markers (AST, ALT), except for compositions 4 and 8 due to their high Transcutol contents (80%). The non-toxic compositions showed a significant increase in free radical scavenger activity measured by the DPPH test compared to the blank SNEDDS. An indirect dissolution test was performed, based on the result of the DPPH antioxidant assay; the dissolution profiles of Plantago lancolata extract were statistically different from each SNEDDS. The anti-inflammatory effect of PL-SNEDDS compositions was confirmed by the ear inflammation test. For the complete examination period, all compositions decreased ear edema as compared to the positive (untreated) control. It can be concluded that PL-SNEDDS compositions could be used to deliver active natural compounds in a stable, efficient, and safe manner.