Bi-layered α-tocopherol acetate loaded membranes for potential wound healing and skin regeneration

Fabrication and Evaluation of a Soy Protein Isolate/Collagen/Sodium Alginate Multifunctional Bilayered Wound Dressing: Release of Cinnamaldehyde, Artemisia absinthium, and Oxygen

Chronic wounds, such as diabetic ulcers and pressure sores, pose significant challenges in modern healthcare due to their prolonged healing times and susceptibility to infections. This study aims to engineer a bilayered wound dressing (BLWD) composed of soy protein isolate/collagen with the ability to release Cinnamaldehyde, Artemisia absinthium (AA), and oxygen. Cinnamaldehyde, magnesium peroxide (MgO2), and AA extract were encapsulated. Nanoparticles were evaluated using scanning electron microscopy (SEM), dynamic light scattering, and ZETA potential tests. Swelling, degradation, water vapor penetration, tensile, MTT, SEM, oxygen release, AA extract release, and antibacterial properties were performed. An in vivo study was carried out to assess the final wound dressing under Hematoxiline&Eosin and Masson trichrome staining analysis and compared to a commercial product. According to the results, the synthesized nanoparticles had an average diameter of about 20 nm with a zeta potential in the range of -20 to -30 mV. The layers had uniform and dense surfaces. The maximum swelling and degradation of the dressing was about 130 and 13% respectively. Generally, better mechanical properties were observed in BLWD than in the single-layer case. More than 90% biocompatibility for the wound dressing was reported. The BLWD could inhibit the growth of Gram-positive and Gram-negative microorganisms. Histopathological analysis showed an acceptable wound-healing property. To sum up, the engineered wound dressing can be a good candidate for more clinical trials.

Lipids Extracted from Mycobacterial Membrane and Enveloped PLGA Nanoparticles for Encapsulating Antibacterial Drugs Elicit Synergistic Antimicrobial Response against Mycobacteria

Tuberculosis (TB) is a chronic disease caused byMycobacterium tuberculosis (Mtb), which shows a long treatment cycle often leads to drug resistance, making treatment more difficult. Immunogens present in the pathogen's cell membrane can stimulate endogenous immune responses. Therefore, an effective lipid-based vaccine or drug delivery vehicle formulated from the pathogen's cell membrane can improve treatment outcomes. Herein, we extracted and characterized lipids fromMycobacterium smegmatis, and the extracts contained lipids belonging to numerous lipid classes and compounds typically found associated with mycobacteria. The extracted lipids were used to formulate biomimetic lipid reconstituted nanoparticles (LrNs) and LrNs-coated poly(lactic-co-glycolic acid) nanoparticles (PLGA-LrNs). Physiochemical characterization and results of morphology suggested that PLGA-LrNs exhibited enhanced stability compared with LrNs. And both of these two types of nanoparticles inhibited the growth of M. smegmatis. After loading different drugs, PLGA-LrNs containing berberine or coptisine strongly and synergistically prevented the growth of M. smegmatis. Altogether, the bacterial membrane lipids we extracted with antibacterial activity can be used as nanocarrier coating for synergistic antibacterial treatment of M. smegmatis─an alternative model of Mtb, which is expected as a novel therapeutic system for TB treatment.

Development of controlled-release antioxidant poly (lactic acid) bilayer active film with different distributions of α-tocopherol and its application in corn oil preservation

The antioxidant poly (lactic acid) bilayer active films with a different distribution of α-tocopherol (TOC) in two layers (outer layer/inner layer: 0%/6%, 2%/4%, 3%/3%, 4%/2%, 6%/0%) were developed. The effects of TOC distribution on the structural, physicochemical, mechanical, antioxidant and release properties of the films and their application in corn oil packaging were investigated. The different distributions of TOC showed insignificant effects on the color, transparency, tensile strength and oxygen and water vapor barrier properties of the films, but it affected the release behavior of TOC from the films into 95% ethanol and the oxidation degree of corn oil. The film with higher TOC in outer layer showed a slower release rate. The corn oil packaged by the film containing 4% TOC in outer layer and 2% TOC in inner layer exhibited the best oxidative stability. This concept showed a great potential to develop controlled-release active films for food packaging.

Construction and Properties of O/W Liquid Crystal Nanoemulsion

Liquid crystal emulsion is a new type of emulsion, in which the emulsifier molecules are located at the oil/water (O/W) interface and form a long-range ordered and short-range disordered lamellar liquid crystal. The lamellar liquid crystal formed by the emulsifier is similar to the skin stratum corneum lipid structure, which enables it to have a broad application prospect in the fields of cosmetics, pharmaceuticals, etc. In this work, a liquid crystal nanoemulsion was obtained by passing a liquid crystal emulsion stabilized by hydrogenated lecithin and phytosterol combination through a microfluidizer. The microstructure of the prepared liquid crystal nanoemulsion was investigated experimentally by dynamic light scattering, transmission electron microscopy, and small-angle X-ray scattering. The results have shown that the nanoemulsion inherited the liquid crystal emulsion property, namely, the long-range ordered and short-range disordered lamellar structure still existed at the oil/water interface even though they underwent extrusion, friction, and acceleration. At the same time, the underlying mechanisms of the existence of lamellar liquid crystal between the oil phase and the water phase for the nanoemulsion were explored theoretically by molecular dynamics simulations. The simulation results elucidated that the hydrogenated lecithin and phytosterol combination improved the flexibility of the bilayer structure composed of emulsifiers. The bilayers were the basic structure units of lamellar liquid crystals, and thus, the improved flexibility of bilayers provided insurance for the existence of lamellar liquid crystals with larger curvature around the oil droplets. In addition, the applicable properties of liquid crystal nanoemulsion were studied, and the results have shown that the liquid crystal nanoemulsion presented better slow-release and moisturizing properties than traditional nanoemulsions due to the existence of multilayers between oil and water phases. This work not only provides necessary information for the development and effective application of liquid crystal emulsions but also is helpful for in-depth understanding the inner properties of lamellar liquid crystal at molecular level.

Fabrication of a core-shell nanofibrous wound dressing with an antioxidant effect on skin injury

Oxidative stress is one of the obstacles preventing wound regeneration, especially for chronic wounds. Herein, designing a wound dressing with an anti-oxidant function holds great appeal for enhancing wound regeneration. In this study, a biocompatible and degradable nanofiber with a core-shell structure was fabricated via coaxial electrospinning, in which polycaprolactone (PCL) was applied as the core structure, while the shell was composed of a mixture of silk fibroin (SF) and tocopherol acetate (TA). The electrospun PST nanofibers were proven to have a network structure with significantly enhanced mechanical properties. The PSTs exhibited a diameter distribution with an average of 321 ± 134 nm, and the water contact angle of their surface is 124 ± 2°. The PSTs also exhibited good tissue compatibility, which can promote the adhesion and proliferation of L929 cells. Besides, the dissolution of silk fibroin encourages the release of TA, which could play a synergistic effect and regulate the oxidative stress effect in the damaged area, for it promotes the adhesion and proliferation of skin fibroblasts (L929), reduces the cytotoxicity of hydrogen peroxide to cells, and lowers the level of reactive oxygen species. The animal experiment indicated that the PSTs would promote the reconstruction of skin. These nanofibers are expected to repair skin ulcers related to diabetes.

Exploring the wound-healing and antimicrobial potential of Dittrichia viscosa L lipidic extract: Chemical composition and in vivo evaluation

Dittrichia viscosa belongs to the Dittrichia genus, it grows abundantly in the east and northeast of Morocco, and traditionally its fresh leaves are crushed and given for topical application after burns, wounds, and infections. In this study, we examine the wound-healing activity of Dittrichia viscosa lipidic extract in vivo, assess its anti-microbial effect, and explore the specific compounds that contribute to these effects. To assess the effectiveness of wound healing, a burn-induced wound model was employed in Wistar rats, and the levels of hydroxyproline as well as histopathological changes in the skin tissues were evaluated. Furthermore, the antimicrobial potential against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Candida glabrata, and Malassezia furfur was investigated using the agar disc diffusion method. Gas Chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) techniques were employed to analyze the composition of fatty acids, phytosterols, and tocopherols. Topical application of Dittrichia viscosa lipidic fraction ointment exhibited significant improvements in wound contraction, achieving an impressive rate of 82% within 21 days. Additionally, the lipidic extract of Dittrichia viscosa displayed notable efficacy against various microbial strains, including Candida albicans (25.07 ± 0.2), Candida glabrata (24 ± 0.6), and Malassezia furfur (22 ± 0.7). The primary fatty acids identified in the sample were linolenic acid (58.95% ± 0), oleic acid (16.75% ±0.04), and linoleic acid (11.97% ± 0.1). Notably, the sample contained significant amounts of γ-Tocopherols (732.08 ± 21mg/kg), while the sterol fraction primarily consisted of 7-Campesterol (1937 ± 0 mg/kg), 7-β-Sitosterol (1621 ± 0 mg/kg), and Stigmasterol (1439 ± 26 mg/kg). By its richness in active compound content, Dittrichia viscosa effectively accelerates wound healing while safeguarding against microbial infections.

Electroconductive Nanofibrous Scaffolds Enable Neuronal Differentiation in Response to Electrical Stimulation without Exogenous Inducing Factors

Among the various biochemical and biophysical inducers for neural regeneration, electrical stimulation (ES) has recently attracted considerable attention as an efficient means to induce neuronal differentiation in tissue engineering approaches. The aim of this in vitro study was to develop a nanofibrous scaffold that enables ES-mediated neuronal differentiation in the absence of exogenous soluble inducers. A nanofibrous scaffold composed of polycaprolactone (PCL), poly-L-lactic acid (PLLA), and single-walled nanotubes (SWNTs) was fabricated via electrospinning and its physicochemical properties were investigated. The cytocompatibility of the electrospun composite with the PC12 cell line and bone marrow-derived mesenchymal stem cells (BMSCs) was investigated. The results showed that the PCL/PLLA/SWNT nanofibrous scaffold did not exhibit cytotoxicity and supported cell attachment, spreading, and proliferation. ES was applied to cells cultured on the nanofibrous scaffolds at different intensities and the expression of the three neural markers (Nestin, Microtubule-associated protein 2, and β tubulin-3) was evaluated using RT-qPCR analysis. The results showed that the highest expression of neural markers could be achieved at an electric field intensity of 200 mV/cm, suggesting that the scaffold in combination with ES can be an efficient tool to accelerate neural differentiation in the absence of exogenous soluble inducers. This has important implications for the regeneration of nerve injuries and may provide insights for further investigations of the mechanisms underlying ES-mediated neuronal commitment.

Physico‐chemical properties and in‐vitro biocompatibility of thermo‐sensitive hydrogel developed with enhanced antimicrobial activity for soft tissue engineering

Smart materials such as thermo‐sensitive in situ forming hydrogels can be effective agents in drug delivery and tissue regeneration with minimal invasion. Injection method would avoid complex surgical procedures facilitating rapid recovery process. In this research, we report the fabrication of an easy, reproducible thermo‐sensitive hydrogel constituting of chitosan (CHI), glycerol phosphate (GP) with variable quantity of ‐poly‐l‐lysine (PS). Fourier‐transform infrared spectra exhibited hydrogel formation where interactions between CHI and GP were seen. The gelation kinetics presented gelation time of 8 min at physiological temperature. The results indicated an increase in degradation rate with the passage of time. Contact angles measurements were employed to observe hydrophilic characteristics which were shown to be favorable. Mechanical strength was determined to be in the range of ~0.1–0.6 MPa for all the hydrogels. Due to intrinsic antibacterial features of CHI and PS, the hydrogels showed potent antibacterial activity against Escherichia coli, Staphylococcus aureus, and Methicillin‐resistant S. aureus (MR‐SA). Interestingly, PS's addition in the hydrogel resulted in potent antibacterial activity against clinically relevant MR‐SA. The hydrogels can hence be delivered to a specific target for localized treatments where the potential of inhibiting multidrug resistant strain is clinically relevant. Biocompatibility of the hydrogels was seen by an overall increase in cell viability of mouse fibroblast cells and scratch assay revealed favorable migration potential. Proangiogenic Vascular endothelial growth factor (VEGF)'s expression showed a gradual increase with increasing concentration of PS, whereas one composition demonstrated a slight increase in the expression of cytosolic prostaglandin E synthase (cPGES) as determined by RT‐PCR. Overall, an increase in PS content of the hydrogels resulted in simultaneously enhanced antibacterial efficiency and marked increase in fibroblast cell viability, hence, reiterating their potential as potent antibacterial agents that can be explored as wound healing agents. In conclusion, novel antibacterial thermo‐sensitive hydrogels were synthesized with a potential of regulating proangiogenic and tissue regeneration factors that highlight their role as wound healing agents.

State-of-the-Art Review of Advanced Electrospun Nanofiber Composites for Enhanced Wound Healing

Wound healing is a complex biological process with four main phases: hemostasis, inflammation, proliferation, and remodeling. Current treatments such as cotton and gauze may delay the wound healing process which gives a demand for more innovative treatments. Nanofibers are nanoparticles that resemble the extracellular matrix of the skin and have a large specific surface area, high porosity, good mechanical properties, controllable morphology, and size. Nanofibers are generated by electrospinning method that utilizes high electric force. Electrospinning device composed of high voltage power source, syringe that contains polymer solution, needle, and collector to collect nanofibers. Many polymers can be used in nanofiber that can be from natural or from synthetic origin. As such, electrospun nanofibers are potential scaffolds for wound healing applications. This review discusses the advanced electrospun nanofiber morphologies used in wound healing that is prepared by modified electrospinning techniques.

ARAG, an Antioxidant-Rich Gel, Shows Superiority to Mepilex Ag in the Treatment of Deep Partial Thickness Burns without Sacrificing Antimicrobial Efficiency

Current treatments for deep tissue burns are limited, and most serve only to enhance hydration or prevent bacterial growth. This leaves burn healing dependent on slow natural processes to debride the wound and reestablish the epidermal and dermal layers of the skin. Infections are well known to destabilize this process through a variety of mechanisms, most notably through increased inflammation and the resulting oxidative stress. In this study, we show that ARAG (an antioxidant-rich antimicrobial gel) can suppress the growth of multiple bacteria commonly found to infect burns (Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, and Staphylococcus aureus). This inhibition is comparable to that conferred by silver ion release from burn dressings such as Mepilex-Ag. We further show, using a porcine model for deep partial-thickness burns, that ARAG allows for enhanced wound healing over Mepilex-Ag, the current standard of care. Histological findings indicate this is likely due to increased wound debridement and dampening of late inflammatory processes, leading to more balanced physiologic healing. Taken together, these findings show promise for ARAG as a superior alternative to the current standard of care.

A Biomimetic, Bilayered Antimicrobial Collagen-Based Scaffold for Enhanced Healing of Complex Wound Conditions

Chronic, nonhealing wounds in the form of diabetic foot ulcers (DFUs) are a major complication for diabetic patients. The inability of a DFU to heal appropriately leads to an open wound with a high risk of infection. Current standards of care fail to fully address either the underlying defective wound repair mechanism or the risk of microbial infection. Thus, it is clear that novel approaches are needed. One such approach is the use of multifunctional biomaterials as platforms to direct and promote wound healing. In this study, a biomimetic, bilayered antimicrobial collagen-based scaffold was developed to deal with the etiology of DFUs. An epidermal, antimicrobial collagen/chitosan film for the prevention of wound infection was combined with a dermal collagen-glycosaminoglycan scaffold, which serves to support angiogenesis in the wound environment and ultimately accelerate wound healing. Biophysical and biological characterization identified an 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide cross-linked bilayered scaffold to have the highest structural stability with similar mechanical properties to products on the market, exhibiting a similar structure to native skin, successfully inhibiting the growth and infiltration of Staphylococcus aureus and supporting the proliferation of epidermal cells on its surface. This bilayered scaffold also demonstrated the ability to support the proliferation of key cell types involved in vascularization, namely, induced pluripotent stem cell derived endothelial cells and supporting stromal cells, with early signs of organization of these cells into vascular structures, showing great promise for the promotion of angiogenesis. Taken together, the results indicate that the bilayered scaffold is an excellent candidate for enhancement of diabetic wound healing by preventing wound infection and supporting angiogenesis.

Protein and polysaccharide-based asymmetric mat with tuned bilayer configuration for enhanced wound healing efficiency

In this research we focused on the fabrication of an asymmetric bilayer membrane with core-shell/simple layer configuration providing the functions of needed hierarchically hydrophilicity and porosity, anti-infectious, tissue adhesion as well as degradation and integration with tissue, cells proliferation, and enhanced promotion of tissue regeneration. The bilayer membrane composed of collagen (Col), chitosan (CS), aloe vera (AV) and gelatin (Gel), not only simulates the features of the epidermis and dermis layer of a natural skin but also benefits from the materials necessary for the regeneration of injured skin tissue during the healing process. The results of full-thickness skin wound evaluation revealed that the fabricated asymmetric membrane could facilitate wound healing within 10 days mainly through enhancing cellular activities, enhancing collagen deposition, and promoting proliferation. Results of histopathological analysis and immunohistochemistry after 10 days of treatment, demonstrated more re-epithelialization and collagen density for the treated groups compared to the control group.

Eggshell membrane-mimicking multifunctional nanofiber for in-situ skin wound healing

Eggshell membrane is a naturally-occurring protective barrier layer for chickens' incubation and shows the close similarity with extracellular matrix. To fully explore and utilize its' structure and active components via a mimicking way will be of great interest for wounds healing. Herein, the well-dispersed CuS nanoparticles were prepared by using eggshell membranes as templates with strong near-infrared absorption and photothermal properties. Furthermore, the as-prepared solution was combined with polyvinyl pyrrolidone and chitosan-derived fluorescent carbon dots for the mimetic synthesis of multifunctional nanofibrous membrane by a hand-held electrospinning device, which has the merits of in-situ operation, the extracellular matrix (ECM)-like architecture, hemostatic, radical scavenging, antibacterial, as well as accelerated healing of skin injury, etc. The electrospun-nanofiber membrane with optimal addition of 100 mg/L CuS nanoparticles was confirmed to be noncytotoxic on human fibroblasts and showed strong antibacterial activities against S. aureus and E. coli under NIR irradiation (980 nm). In addition, the radical scavenging ability was also proved by DPPH experiments. The animal experiments revealed that the nanofiber membrane could accelerate the wound healing process. The work lays down a simple and environmentally-friendly approach for the fabrication and development of promising wound healing materials in skin tissue engineering applications.

A bi-layered scaffold of a poly(lactic-co-glycolic acid) nanofiber mat and an alginate-gelatin hydrogel for wound healing

A resveratrol-loaded bi-layered scaffold (RBS) that consists of a resveratrol-loaded poly(lactic-co-glycolic acid) (Res-PLGA) electrospinning nanofiber mat (upper layer) and an alginate di-aldehyde (ADA)-gelatin (GEL) crosslinking hydrogel (ADA-GEL) (lower layer) was fabricated as a wound dressing material. It was made through mimicking the epidermis and dermis of the skin. The RBS exhibited good hemostatic ability and proper swelling ability. Furthermore, HaCaT cells and human embryonic skin fibroblasts (ESFs) were also cultured in the nanofiber layer and hydrogel layer of RBS, and the results indicated that both HaCaT and ESFs could grow well in the materials. The in vivo experiment using a Sprague-Dawley (SD) rat skin wound as a model showed that the RBS could accelerate the wound healing rate compared with the Res-PLGA group and ADA4-GEL6 group. These results indicated that this resveratrol-loaded bi-layered scaffold can be a potential candidate in promoting wound healing.

Experimental Models to Study Skin Wound Healing with a Focus on Angiogenesis

A large number of models are now available for the investigation of skin wound healing. These can be used to study the processes that take place in a phase-specific manner under both physiological and pathological conditions. Most models focus on wound closure, which is a crucial parameter for wound healing. However, vascular supply plays an equally important role and corresponding models for selective or parallel investigation of microcirculation regeneration and angiogenesis are also described. In this review article, we therefore focus on the different levels of investigation of skin wound healing (in vivo to in virtuo) and the investigation of angiogenesis and its parameters.

Vitamin E: A Review of Its Application and Methods of Detection When Combined with Implant Biomaterials

Vitamin E is a common compound used for tocopherols and tocotrienols (α, β, γ, δ); it is the component of many natural products of both plant and animal origin. Thanks to its powerful antioxidant capacity, vitamin E has been very successful in hip and knee arthroplasty, used to confer resistance to oxidation to irradiated UHMWPE. The positive results of these studies have made vitamin E an important object of research in the biomedical field, highlighting other important properties, such as anti-bacterial, -inflammatory, and -cancer activities. In fact, there is an extensive literature dealing with vitamin E in different kinds of material processing, drug delivery, and development of surface coatings. Vitamin E is widely discussed in the literature, and it is possible to find many reviews that discuss the biological role of vitamin E and its applications in food packaging and cosmetics. However, to date, there is not a review that discusses the biomedical applications of vitamin E and that points to the methods used to detect it within a solid. This review specifically aims to compile research about new biomedical applications of vitamin E carried out in the last 20 years, with the intention of providing an overview of the methodologies used to combine it with implantable biomaterials, as well as to detect and characterize it within these materials.

Chemical Composition, Antioxidant and Cytoprotective Potentials of Carica papaya Leaf Extracts: A Comparison of Supercritical Fluid and Conventional Extraction Methods

The leaves of Carica papaya (CP) are rich in natural antioxidants. Carica papaya has traditionally been used to treat various ailments, including skin diseases. This study aims to decipher the antioxidant effects and phytochemical content of different CP leaf extracts (CPEs) obtained using supercritical carbon dioxide (scCO₂) and conventional extraction methods. The antioxidant activities of CPEs were evaluated by cell-free (1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric-reduced antioxidative power (FRAP)) and cell-based (H₂O₂) assay. Both C. papaya leaf scCO₂ extract with 5% ethanol (CPSCE) and C. papaya leaf scCO₂ extract (CPSC) exhibited stronger DPPH radical scavenging activity than conventional extracts. In the FRAP assay, two hydrophilic extracts (C. papaya leaf ethanol extract (CPEE) and C. papaya freeze-dried leaf juice (CPFD)) showed relatively stronger reducing power compared to lipophilic extracts. Cell-based assays showed that CPFD significantly protected skin fibroblasts from H₂O₂-induced oxidative stress in both pre-and post-treatment. CPEE protected skin fibroblasts from oxidative stress in a dose-dependent manner while CPSCE significantly triggered the fibroblast recovery after treatment with H₂O₂. GC-MS analysis indicated that CPSCE had the highest α-tocopherol and squalene contents. By contrast, both CP hydrophilic extracts (CPEE and CPFD) had a higher total phenolic content (TPC) and rutin content than the lipophilic extracts. Overall, CPEs extracted using green and conventional extraction methods showed antioxidative potential in both cell-based and cell-free assays due to their lipophilic and hydrophilic antioxidants, respectively.

Electrospun Asymmetric Membranes as Promising Wound Dressings: A Review

Despite all the efforts that have been done up to now, the currently available wound dressings are still unable to fully re-establish all the structural and functional properties of the native skin. To overcome this situation, researchers from the tissue engineering area have been developing new wound dressings (hydrogels, films, sponges, membranes) aiming to mimic all the features of native skin. Among them, asymmetric membranes emerged as a promising solution since they reproduce both epidermal and dermal skin layers. Wet or dry/wet phase inversion, scCO2-assisted phase inversion, and electrospinning have been the most used techniques to produce such a type of membranes. Among them, the electrospinning technique, due to its versatility, allows the development of multifunctional dressings, using natural and/or synthetic polymers, which resemble the extracellular matrix of native skin as well as address the specific requirements of each skin layer. Moreover, various therapeutic or antimicrobial agents have been loaded within nanofibers to further improve the wound healing performance of these membranes. This review article provides an overview of the application of asymmetric electrospun membranes as wound dressings displaying antibacterial activity and as delivery systems of biomolecules that act as wound healing enhancers.

The leaves of Bougainvillea spectabilis suppressed inflammation and nociception in vivo through the modulation of glutamatergic, cGMP, and ATP-sensitive K+ channel pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Bougainvillea spectabilis is an ornamental shrub from Nyctaginaceae family, widely used in the traditional medicine in the treatment of pain, inflammation, and ulcer. Some research investigated the analgesic potential of this plant, however, the in-depth analysis of its antinociceptive properties and molecular mechanism(s) are yet to be revealed.

PURPOSE OF THE STUDY

This study, therefore, investigated the antinociceptive potential of methanol extract of the leaves of B. spectabilis (MEBS) with possible molecular mechanism(s) of action using several pre-clinical models of acute and chronic pain in mice.

MATERIALS AND METHODS

The dry leaf powder of B. spectabilis was macerated with 100% methanol, and then dried crude extract was used for in vivo experiments. Following the acute toxicity test with 500, 1000, and 2000 mg/kg b.w. doses of MEBS, the central antinociceptive activities of the extract (50, 100, and 200 mg/kg b.w.) were evaluated using hot plate and tail immersion tests, whereas the peripheral activities were investigated using acetic acid-induced writhing, formalin-induced licking and oedema, and glutamate-induced licking tests. Moreover, the possible involvements of cGMP and ATP-sensitive K+ channel pathways in the observed antinociceptive activities were also investigated using methylene blue (20 mg/kg b.w.) and glibenclamide (10 mg/kg b.w.), respectively. We also performed GC/MS-MS analysis of MEBS to identify the phyto-constituents and in silico modelling of the major compounds for potential molecular targets.

RESULTS

Our results demonstrated that MEBS at 50, 100, and 200 mg/kg b.w. doses were not effective enough to suppress centrally mediated pain in the hot plate and tail immersion models. However, the extract was potent (at 100 and 200 mg/kg b.w. doses) in reducing peripheral nociception in the acetic acid-induced writhing and inflammatory phase of the formalin tests. Further analyses revealed that MEBS could interfere with glutamatergic system, cGMP and ATP-sensitive K⁺ channel pathways to show its antinociceptive properties. GC/MS-MS analysis revealed 35 different phytochemicals with potent anti-inflammatory and antinociceptive properties including phytol, neophytadiene, 2,4-Di-tert-butylphenol, fucoxanthin, and Vit-E. Prediction analysis showed high intestinal absorptivity and low toxicity profiles of these compounds with capability to interact with glutamatergic system, inhibit JAK/STAT pathway, scavenge nitric oxide and oxygen radicals, and inhibit expression of COX3, tumor necrosis factor, and histamine.

CONCLUSION

Taken together, these results suggested the antinociceptive potentials of MEBS which were mediated through the modulation of glutamatergic, cGMP, and ATP-sensitive K⁺ channel pathways. These also suggested that MEBS could be beneficial in the treatment of complications associated with nociceptive pain.