Nanoemulsion Thermoreversible Pluronic F127-Based Hydrogel Containing Hyptis pectinata (Lamiaceae) Leaf Essential Oil Produced a Lasting Anti-hyperalgesic Effect in Chronic Noninflammatory Widespread Pain in Mice

H. pectinata (L.) Poit - Traditional uses, phytochemistry and biological-pharmacological activities in preclinical studies: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

H. pectinata (L.) Poit, popularly known as "sambacaitá" or "canudinho", is a plant endemic to north-eastern Brazil. Its aerial parts, leaves and flowers have traditionally been used to treat gastrointestinal disorders, rhinopharyngitis, nasal congestion, bacterial and fungal infections, fever, colic, inflammation, and pain.

AIM OF THE STUDY

The aim of this review was to provide information on the botanical characteristics, ethnomedicinal uses, phytochemistry and biological-pharmacological activities of H. pectinata.

MATERIALS AND METHODS

This systematic review followed the Cochrane Handbook Collaboration and the PRISMA guidelines. The review question was what are the biological-pharmacological activities of H. pectinata presented in non-clinical studies. The search for articles was conducted in the Medline (via PubMed), Embase, Web of Science, Scopus, Virtual Health Library, SciELO, Google Scholar and the Brazilian Digital Library of Theses and Dissertations databases. Two reviewers independently selected the studies that met the inclusion criteria, extracted the data, and assessed the risk of bias of the included studies.

RESULTS

39 articles were included in this review, of which 19 reported in vitro experiments, 16 in vivo studies and 4 in vivo and in vitro experiments. H. pectinata is a plant widely used in folk medicine in north-eastern Brazil for the treatment of various ailments, such as respiratory diseases, gastrointestinal disorders, bacterial and fungal infections, and general inflammation. Supporting its popular use, several in vitro and in vivo pharmacological investigations of the essential oil and extract of H. pectinata have demonstrated their anti-inflammatory, antinociceptive, antioxidant, antidepressant, anticancer, hepatoregenerative, healing, and antimicrobial activities. H. pectinata has been reported to contain 75 bioactive constituents, comprising 9 flavonoids, 54 terpenes, and 12 other compounds.

CONCLUSION

H. pectinata is a plant commonly used in traditional medicine. Phytochemically, it contains several bioactive constituents, including terpenes and flavonoids, and has been shown to have antinociceptive, anti-inflammatory, antimicrobial and antitumour activity, as well as hepatorregenerative and healing effects, and low toxicity.

Essential Oils from the Genus Piper Promote Antinociception by Modulating TRP Channels and Anti-Inflammatory Effects in Adult Zebrafish

The Piper genus, known for its pharmacological potential, comprises 2,263 species primarily found in tropical regions. Despite recent advancements in pain therapies, the demand for more effective and well-tolerated analgesics and anti-inflammatories, particularly for chronic pain, remains. This study assessed the effects of essential oils from Piper caldense, Piper mosenii, and Piper mikanianum on nociceptive behavior induced by formalin and capsaicin, as well as their anti-inflammatory impact induced by carrageenan, using adult zebrafish models. Results indicated non-toxic essential oils with antinociceptive properties in both neurogenic and inflammatory phases of formalin-induced nociception through interaction with the TRPA1 receptor. Additionally, P. mosenii essential oil also blocked the nociceptive effect of capsaicin, a TRPV1 receptor agonist. Furthermore, essential oils from P. caldense and P. mikanianum exhibited significant anti-inflammatory effects by reducing carrageenan-induced abdominal edema. These findings highlight the pharmacological potential of Piper's essential oils as antinociceptive and anti-inflammatory agents.

Pluronic F68 Micelles as Carriers for an Anti-Inflammatory Drug: A Rheological and Scattering Investigation

Age-long ambition of medical scientists has always been advancement in healthcare and therapeutic medicine. Biomedical research indeed claims paramount importance in nanomedicine and drug delivery, and the development of biocompatible storage structures for delivering drugs stands at the heart of emerging scientific works. The delivery of drugs into the human body is nevertheless a nontrivial and challenging task, and it is often addressed by using amphiphilic compounds as nanosized delivery vehicles. Pluronics belong to a peculiar class of biocompatible and thermosensitive nonionic amphiphilic copolymers, and their self-assemblies are employed as drug delivery excipients because of their unique properties. We herein report on the encapsulation of diclofenac sodium within Pluronic F68 self-assemblies in water, underpinning the impact of the drug on the rheological and microstructural evolution of pluronic-based systems. The self-assembly and thermoresponsive micellization were studied through isothermal steady rheological experiments at different temperatures on samples containing 45 wt % Pluronic F68 and different amounts of diclofenac sodium. The adoption of scattering techniques, small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS), allowed for the description of the system features at the nanometer length scale, providing information about the characteristic size of each part of the micellar structures as a function of temperature and drug concentration. Diclofenac sodium is not a good fellow for Pluronic F68. The triblock copolymer aids the encapsulation of the drug, highly improving its water solubility, whereas diclofenac sodium somehow hinders Pluronic self-assembly. By using a simple empirical model and no fitting parameters, the steady viscosity can be predicted, although qualitatively, through the volume fraction of the micelles extracted through scattering techniques and compared to the rheological one. A tunable control of the viscous behavior of such biomedical systems may be achieved through the suitable choice of their composition.

Phase transitions of aqueous solutions of Pluronic F68 in the presence of Diclofenac Sodium

In recent years, advancements in bioengineering and materials science have witnessed increasing interest in synthetic polymers capable of fulfilling various applications. Owing to their distinctive properties, Pluronics can be used as nano-drug carriers, to deliver poorly water-soluble drugs, and as model systems to study colloidal science by tuning amphiphilic properties. In this work, we investigated the effect of diclofenac sodium on the self-assembly and thermoresponsive crystallization of Pluronic F68 in water solutions, by employing experimental rheology and Nuclear Magnetic Resonance (NMR). We built a complete phase diagram as a function of temperature and concentration for 45 wt% Pluronic F68 with various amounts of diclofenac sodium in water. The morphological transitions were followed as a function of temperature via linear rheology. We extrapolated the transition temperatures - identifying distinct phases - as a function of the drug concentration and proposed an empirical model for their prediction. NMR analysis provided further information on the structural characteristics of the systems, shedding light on the interactions between F68 and diclofenac sodium. Although dealing with a pharmaceutical salt, the study is focused on a colloidal system and its interaction with a binding molecule, that is of general interest for colloidal science.

5-Fluorouracil-Immobilized Hyaluronic Acid Hydrogel Arrays on an Electrospun Bilayer Membrane as a Drug Patch

The hyaluronic acid (HA) hydrogel array was employed for immobilization of 5-fluorouracil (5-FU), and the electrospun bilayer (hydrophilic: polyurethane/pluronic F-127 and hydrophobic: polyurethane) membrane was used to support the HA hydrogel array as a patch. To visualize the drug propagating phenomenon into tissues, we experimentally investigated how FITC-BSA diffused into the tissue by applying hydrogel patches to porcine tissue samples. The diffusive phenomenon basically depends on the FITC-BSA diffusion coefficient in the hydrogel, and the degree of diffusion of FITC-BSA may be affected by the concentration of HA hydrogel, which demonstrates that the high density of HA hydrogel inhibits the diffusive FITC-BSA migration toward the low concentration region. YD-10B cells were employed to investigate the release of 5-FU from the HA array on the bilayer membrane. In the control group, YD-10B cell viability was over 98% after 3 days. However, in the 5-FU-immobilized HA hydrogel array, most of the YD-10B cells were not attached to the bilayer membrane used as a scaffold. These results suggest that 5-FU was locally released and initiated the death of the YD-10B cells. Our results show that 5-FU immobilized on HA arrays significantly reduces YD-10B cell adhesion and proliferation, affecting cells even early in the cell culture. Our results suggest that when 5-FU is immobilized in the HA hydrogel array on the bilayer membrane as a drug patch, it is possible to control the drug concentration, to release it continuously, and that the patch can be applied locally to the targeted tumor site and administer the drug in a time-stable manner. Therefore, the developed bilayer membrane-based HA hydrogel array patch can be considered for sustained release of the drug in biomedical applications.

Application Status of Sacrificial Biomaterials in 3D Bioprinting

Additive manufacturing, also known as three-dimensional (3D) printing, relates to several rapid prototyping (RP) technologies, and has shown great potential in the manufacture of organoids and even complex bioartificial organs. A major challenge for 3D bioprinting complex org unit ans is the competitive requirements with respect to structural biomimeticability, material integrability, and functional manufacturability. Over the past several years, 3D bioprinting based on sacrificial templates has shown its unique advantages in building hierarchical vascular networks in complex organs. Sacrificial biomaterials as supporting structures have been used widely in the construction of tubular tissues. The advent of suspension printing has enabled the precise printing of some soft biomaterials (e.g., collagen and fibrinogen), which were previously considered unprintable singly with cells. In addition, the introduction of sacrificial biomaterials can improve the porosity of biomaterials, making the printed structures more favorable for cell proliferation, migration and connection. In this review, we mainly consider the latest developments and applications of 3D bioprinting based on the strategy of sacrificial biomaterials, discuss the basic principles of sacrificial templates, and look forward to the broad prospects of this approach for complex organ engineering or manufacturing.

A Recent Update on Drug Delivery Systems for Pain Management

Pain remains a global health challenge affecting approximately 1.5 billion people worldwide. Pain has been an implicit variable in the equation of human life for many centuries considering different types and the magnitude of pain. Therefore, developing an efficacious drug delivery system for pain management remains an open challenge for researchers in the field of medicine. Lack of therapeutic efficacy still persists, despite high throughput studies in the field of pain management. Research scientists have been exploiting different alternatives to curb the adverse side effects of pain medications or attempting a more substantial approach to minimize the prevalence of pain. Various drug delivery systems have been developed such as nanoparticles, microparticles to curb adverse side effects of pain medications or minimize the prevalence of pain. This literature review firstly provides a brief introduction of pain as a sensation and its pharmacological interventions. Second, it highlights the most recent studies in the pharmaceutical field for pain management and serves as a strong base for future developments. Herein, we have classified drug delivery systems based on their sizes such as nano, micro, and macro systems, and for each of the reviewed systems, design, formulation strategies, and drug release performance has been discussed.

Fibromyalgia: Pathogenesis, Mechanisms, Diagnosis and Treatment Options Update

Fibromyalgia is a syndrome characterized by chronic and widespread musculoskeletal pain, often accompanied by other symptoms, such as fatigue, intestinal disorders and alterations in sleep and mood. It is estimated that two to eight percent of the world population is affected by fibromyalgia. From a medical point of view, this pathology still presents inexplicable aspects. It is known that fibromyalgia is caused by a central sensitization phenomenon characterized by the dysfunction of neuro-circuits, which involves the perception, transmission and processing of afferent nociceptive stimuli, with the prevalent manifestation of pain at the level of the locomotor system. In recent years, the pathogenesis of fibromyalgia has also been linked to other factors, such as inflammatory, immune, endocrine, genetic and psychosocial factors. A rheumatologist typically makes a diagnosis of fibromyalgia when the patient describes a history of pain spreading in all quadrants of the body for at least three months and when pain is caused by digital pressure in at least 11 out of 18 allogenic points, called tender points. Fibromyalgia does not involve organic damage, and several diagnostic approaches have been developed in recent years, including the analysis of genetic, epigenetic and serological biomarkers. Symptoms often begin after physical or emotional trauma, but in many cases, there appears to be no obvious trigger. Women are more prone to developing the disease than men. Unfortunately, the conventional medical therapies that target this pathology produce limited benefits. They remain largely pharmacological in nature and tend to treat the symptomatic aspects of various disorders reported by the patient. The statistics, however, highlight the fact that 90% of people with fibromyalgia also turn to complementary medicine to manage their symptoms.

Meniscus regeneration with injectable Pluronic/PMMA-reinforced fibrin hydrogels in a rabbit segmental meniscectomy model

Injectable hydrogel systems are a facile approach to apply to the damaged meniscus in a minimally invasive way. We herein developed a clinically applicable and injectable semi-interpenetrated network (semi-IPN) hydrogel system based on fibrin (Fb), reinforced with Pluronic F127 (F127) and polymethyl methacrylate (PMMA), to improve the intrinsic weak mechanical properties. Through the dual-syringe device system, the hydrogel could form a gel state within about 50 s, and the increment of compressive modulus of Fb hydrogels was achieved by adding F127 from 3.0% (72.0 ± 4.3 kPa) to 10.0% (156.0 ± 9.8 kPa). The shear modulus was enhanced by adding PMMA microbeads (26.0 ± 1.1 kPa), which was higher than Fb (13.5 ± 0.5 kPa) and Fb/F127 (21.7 ± 0.8 kPa). Moreover, the addition of F127 and PMMA also delayed the rate of enzymatic biodegradation of Fb hydrogel. Finally, we confirmed that both Fb/F127 and Fb/F127/PMMA hydrogels showed accelerated tissue repair in the in vivo segmental defect of the rabbit meniscus model. In addition, the histological analysis showed that the quality of the regenerated tissues healed by Fb/F127 was particularly comparable to that of healthy tissue. The biomechanical strength of the regenerated tissues of Fb/F127 (3.50 ± 0.35 MPa) and Fb/F127/PMMA (3.59 ± 0.89 MPa) was much higher than that of Fb (0.82 ± 0.05 MPa) but inferior to that of healthy tissue (6.63 ± 1.12 MPa). These results suggest that the reinforcement of Fb hydrogel using FDA-approved synthetic biomaterials has great potential to be used clinically.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).

Poloxamer: A versatile tri-block copolymer for biomedical applications

Poloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). Some chemical characteristics of poloxamers such as temperature-dependent self-assembly and thermo-reversible behavior along with biocompatibility and physiochemical properties make poloxamer-based biomaterials promising candidates for biomedical application such as tissue engineering and drug delivery. The microstructure, bioactivity, and mechanical properties of poloxamers can be tailored to mimic the behavior of various types of tissues. Moreover, their amphiphilic nature and the potential to self-assemble into the micelles make them promising drug carriers with the ability to improve the drug availability to make cancer cells more vulnerable to drugs. Poloxamers are also used for the modification of hydrophobic tissue-engineered constructs. This article collects the recent advances in design and application of poloxamer-based biomaterials in tissue engineering, drug/gene delivery, theranostic devices, and bioinks for 3D printing. STATEMENT OF SIGNIFICANCE: Poloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). The microstructure, bioactivity, and mechanical properties of poloxamers can be tailored to mimic the behavior of various types of tissues. Moreover, their amphiphilic nature and the potential to self-assemble into the micelles make them promising drug carriers with the ability to improve the drug availability to make cancer cells more vulnerable to drugs. However, no reports have systematically reviewed the critical role of poloxamer for biomedical applications. Research on poloxamers is growing today opening new scenarios that expand the potential of these biomaterials from "traditional" treatments to a new era of tissue engineering. To the best of our knowledge, this is the first review article in which such issue is systematically reviewed and critically discussed in the light of the existing literature.

Antinociceptive Activity of Chemical Components of Essential Oils That Involves Docking Studies: A Review

INTRODUCTION

Pain is considered an unpleasant sensory and emotional experience, being considered as one of the most important causes of human suffering. Computational chemistry associated with bioinformatics has stood out in the process of developing new drugs, through natural products, to manage this condition.

OBJECTIVE

To analyze, through literature data, recent molecular coupling studies on the antinociceptive activity of essential oils and monoterpenes.

DATA SOURCE

Systematic search of the literature considering the years of publications between 2005 and December 2019, in the electronic databases PubMed and Science Direct.

ELIGIBILITY CRITERIA

Were considered as criteria of 1) Biological activity: non-clinical effects of an OE and/or monoterpenes on antinociceptive activity based on animal models and in silico analysis, 2) studies with plant material: chemically characterized essential oils and/or their constituents isolated, 3) clinical and non-clinical studies with in silico analysis to assess antinociceptive activity, 4) articles published in English. Exclusion criteria were literature review, report or case series, meta-analysis, theses, dissertations, and book chapter.

RESULTS

Of 16,006 articles, 16 articles fulfilled all the criteria. All selected studies were non-clinical. The most prominent plant families used were Asteraceae, Euphorbiaceae, Verbenaceae, Lamiaceae, and Lauraceae. Among the phytochemicals studied were α-Terpineol, 3-(5-substituted-1,3,4-oxadiazol-2-yl)-N'-[2-oxo-1,2-dihydro-3H-indol-3-ylidene] propane hydrazide, β-cyclodextrin complexed with citronellal, (-)-α-bisabolol, β-cyclodextrin complexed with farnesol, and p-Cymene. The softwares used for docking studies were Molegro Virtual Docker, Sybyl®X, Vlife MDS, AutoDock Vina, Hex Protein Docking, and AutoDock 4.2 in PyRx 0.9. The molecular targets/complexes used were Nitric Oxide Synthase, COX-2, GluR2-S1S2, TRPV1, β-CD complex, CaV1, CaV2.1, CaV2.2, and CaV2.3, 5-HT receptor, delta receptor, kappa receptor, and MU (μ) receptor, alpha adrenergic, opioid, and serotonergic receptors, muscarinic receptors and GABAA opioid and serotonin receptors, 5-HT3 and M2 receptors. Many of the covered studies used molecular coupling to investigate the mechanism of action of various compounds, as well as molecular dynamics to investigate the stability of protein-ligand complexes.

CONCLUSIONS

The studies revealed that through the advancement of more robust computational techniques that complement the experimental studies, they may allow some notes on the identification of a new candidate molecule for therapeutic use.

Phytol, a Chlorophyll Component, Produces Antihyperalgesic, Anti-inflammatory, and Antiarthritic Effects: Possible NFκB Pathway Involvement and Reduced Levels of the Proinflammatory Cytokines TNF-α and IL-6

Phytol is a diterpene constituent of chlorophyll and has been shown to have several pharmacological properties, particularly in relation to the management of painful inflammatory diseases. Arthritis is one of the most common of these inflammatory diseases, mainly affecting the synovial membrane, cartilage, and bone in joints. Proinflammatory cytokines, such as TNF-α and IL-6, and the NFκB signaling pathway play a pivotal role in arthritis. However, as the mechanisms of action of phytol and its ability to reduce the levels of these cytokines are poorly understood, we decided to investigate its pharmacological effects using a mouse model of complete Freund's adjuvant (CFA)-induced arthritis. Our results showed that phytol was able to inhibit joint swelling and hyperalgesia throughout the whole treatment period. Moreover, phytol reduced myeloperoxidase (MPO) activity and proinflammatory cytokine release in synovial fluid and decreased IL-6 production as well as the COX-2 immunocontent in the spinal cord. It also downregulated the p38MAPK and NFκB signaling pathways. Therefore, our findings demonstrated that phytol can be an innovative antiarthritic agent due to its capacity to attenuate inflammatory reactions in joints and the spinal cord, mainly through the modulation of mediators that are key to the establishment of arthritic pain.

Eplingiella fruticosa (Lamiaceae) essential oil complexed with β-cyclodextrin improves its anti-hyperalgesic effect in a chronic widespread non-inflammatory muscle pain animal model

Eplingiella fruticosa (Lamiaceae), formally known as Hyptis fruticosa, is an important aromatic medicinal herb used in folk medicine in northeastern Brazil. We aimed to evaluate the anti-hyperalgesic effect of essential oil obtained from E. fruticosa (HypEO) complexed with βCD (HypEO-βCD) in a chronic widespread non-inflammatory muscle pain animal model (a mice fibromyalgia-like model, FM). The HypEO was extracted by hydro distillation and its chemical composition was determined by GC-MS/FID. Moreover, Fos protein expression in the spinal cord was assessed by immunofluorescence. (E)-caryophyllene, bicyclogermacrene, 1,8-cineole, α-pinene, β-pinene and 21 other compounds were identified in the HypEO. The treatment with HypEO-βCD produced a longer-lasting anti-hyperalgesic effect compared to HypEO, without alterations in motor coordination or myorelaxant effects. Moreover, HypEO and HypEO-βCD produced a significant anti-hyperalgesic effect over 7 consecutive treatment days. Immunofluorescence assay demonstrated a decrease in Fos protein expression in the spinal cord (p < 0.001). We demonstrated that the anti-hyperalgesic effect produced by HypEO was improved after complexation with β-CD and this seems to be related to the central pain-inhibitory pathway, suggesting the possible use of E. fruticosa for chronic pain management.

Natural products as a perspective for cancer pain management: A systematic review

BACKGROUND

Cancer is the leading cause of death in the world and one of the main symptoms affecting these individuals is chronic pain, which must be evaluated and treated in its various components. Several drugs are currently used, but beyond the high cost, they have harmful side effects to patients or are transitorily effective. Ergo, there is a need to look for new options for cancer pain relief. Natural products (NPs) present themselves as strong candidates for the development of new drugs for the treatment of chronic pain, such as cancer pain.

PURPOSE

This systematic review aimed to summarize current knowledge about the analgesic profile of NPs in cancer pain.

METHODS

The search included PubMed, Scopus and Web of Science (from inception to June 2018) sought to summarize the articles studying new proposals with NPs for the management of oncological pain. Two independent reviewers extracted data on study characteristics, methods and outcomes.

RESULTS

After an extensive survey, 21 articles were selected, which described the analgesic potential of 15 natural compounds to relieve cancer pain. After analyzing the data, it can be suggested that these NPs, which have targets in central and peripheral mechanisms, are interesting candidates for the treatment of cancer pain for addressing different pharmacological mechanisms (even innovative), but ensuring the safety of these compounds is still a challenge. Likewise, the cannabinoids compounds leave the front as the most promising compounds for direct applicability due to the clinical studies that have already been developed and the background already established about these effects on chronic pain.

CONCLUSION

Regarding these findings, it can be concluded that the variability of possible biological sites of action is strategic for new perspectives in the development of therapeutic proposals different from those available in the current market.