Anti-inflammatory activity of novel ammonium glycyrrhizinate/niosomes delivery system: Human and murine models

Topically applied lipid- and surfactant-based nanoparticles in the treatment of skin disorders

INTRODUCTION

In the treatment of dermatological disorders, topical drug administration is a mainstay. However, nanoparticle-based carrier systems could improve and expand the current therapeutic range via localized delivery of active ingredients. Areas covered: This review gives a detailed description of lipid- and surfactant-based drug delivery systems which have been explored for topical drug administration. To guide researchers in their choice of delivery system, an informative decision tree is included. Moreover, this review provides a complete overview of the topical or transdermal drug products, currently on the market or under clinical investigation, delivered via the discussed carriers, in the treatment of skin disorders. Expert opinion: Conventional liposomes are still popular in the domain of topical or transdermal drug delivery and dominate the market landscape. However, several other carriers, such as exosomes and niosomes, are being explored which offer distinct advantages over liposomes and should therefore not be disregarded when selecting a proper drug delivery system.

European medicinal and edible plants associated with subacute and chronic toxicity part I: Plants with carcinogenic, teratogenic and endocrine-disrupting effects

In recent decades, the use of herbal medicines and food products has been widely embraced in many developed countries. These products are generally highly accepted by consumers who often believe that "natural" equals "safe". This is, however, an oversimplification because several botanicals have been found to contain toxic compounds in concentrations harmful to human health. Acutely toxic plants are in most cases already recognised as dangerous as a result of their traditional use, but plants with subacute and chronic toxicity are difficult or even impossible to detect by traditional use or by clinical research studies. In this review, we systematically address major issues including the carcinogenicity, teratogenicity and endocrine-disrupting effects associated with the use of herbal preparations with a strong focus on plant species that either grow natively or are cultivated in Europe. The basic information regarding the molecular mechanisms of the individual subtypes of plant-induced non-acute toxicity is given, which is followed by a discussion of the pathophysiological and clinical characteristics. We describe the genotoxic and carcinogenic effects of alkenylbenzenes, pyrrolizidine alkaloids and bracken fern ptaquiloside, the teratogenicity issues regarding anthraquinone glycosides and specific alkaloids, and discuss the human health concerns regarding the phytoestrogens and licorice consumption in detail.

Formulation design and characterization of a non-ionic surfactant based vesicular system for the sustained delivery of a new chondroprotective agent

Diacerein is used for symptomatic relief and cartilage regeneration in osteoarthritis. Due to gastrointestinal side effects, poor aqueous solubility and low bioavailability, its clinical usage has been restricted. The objective of the present study was to enhance its dissolution profile and to attain sustained release by designing a novel delivery system based on niosomes. Five niosomal formulations (F1-F5) with non-ionic surfactant (sorbitan monostearate) and cholesterol in varying ratios of 5:5, 6:4, 7:3, 8:2 and 9:1 were developed by the reverse-phase evaporation technique. The size and polydispersivity index (PDI) were found in the range of 0.608 µm to 1.010 µm and 0.409 to 0.781, respectively. Scanning electron microscopy (SEM) of the selected formulation (F3) revealed spherical vesicles, and 79.8% entrapment was achieved with F3 (7:3). Dissolution studies using the dialysis method showed sustained release behaviour for all formulations. The optimized surfactant-to-cholesterol concentration (7:3) in formulation F3sustained the drug-release time (T50%) up to 10 hours. Kinetic modelling exhibited a zero-order release (R2=0.9834) and the release exponent 'n' of the Korsmayer-Peppas model (n=0.90) confirmed non-fickian and anomalous release. The results of this study suggest that diacerein can be successfully entrapped into niosomes using sorbitan monostearate and that these niosomes have the potential to deliver diacerein efficiently at the absorption site.

Delivery of liquorice extract by liposomes and hyalurosomes to protect the skin against oxidative stress injuries

Liquorice extract, obtained by percolation in ethanol of Glycyrrhiza glabra L. roots, was incorporated in liposomes and hyalurosomes, new phospholipid-sodium hyaluronate vesicles, and their protective effect against oxidative stress skin damages was probed. As a comparison, raw glycyrrhizin was also tested. All the vesicles were small in size (≤ 100 nm), with a highly negative zeta potential ensuring long-term stability, and able to incorporate a high amount of the extract. In vitro tests showed that the liquorice extract loaded in vesicles was able to scavenge DPPH free radical (80% inhibition) and to protect 3T3 fibroblasts against H2O2-induced oxidative stress, restoring the normal conditions. By contrast, glycyrrhizin showed poor antioxidant activity, and was not able to efficiently counteract the oxidative effect of H2O2. In addition, the incorporation of the liquorice extract into the vesicular systems promoted the proliferation and migration of 3T3 fibroblasts, favouring the closure of the scratched area. In vivo anti-inflammatory tests on mice confirmed the ability of the proposed nanosystems to improve the local efficacy of the extract, favouring the re-epitelization process.

Nanotechnological approaches for the effective management of psoriasis

Psoriasis is a chronic disorder with erythematous scaly patches, which typically affects the exposed surfaces of the body and scalp. Various factors such as bacterial infection, genetic and environmental factors, and immune disorders play an important role in causing psoriasis. Different types of psoriasis can be observed, such as guttate psoriasis, inverse psoriasis, pustular psoriasis, and psoriatic arthritis. Various ancient, topical, and systemic approaches have been used to control the disease, but have failed to achieve a complete reduction of the disease, besides causing toxic effects. Therefore, our main aim in this review article is to introduce the different advanced nanotechnological approaches for effective treatment of psoriasis.

Formulation of resveratrol entrapped niosomes for topical use

A new approach to the formulation of resveratrol (RSV) entrapped niosomes for topical use is proposed in this work. Niosomes were formulated with Gelot 64 (G64) as surfactant, and two skin-compatible unsaturated fatty acids (oleic and linoleic acids), commonly used in pharmaceutical formulations, as penetration enhancers. Niosomes were prepared by two different methods: a thin film hydration method with minor modifications followed by a sonication stage (TFH-S), and an ethanol injection modified method (EIM). Niosomes prepared with the EIM method were in the range of 299-402 nm, while the TFH-S method produced larger niosomes in the range of 293-496 nm. Moreover, niosomes with higher RSV entrapment efficiency (EE) and better stability were generated by the EIM method. Ex vivo transdermal experiments, carried out in Franz diffusion cells on newborn pig skin, indicated that niosomes prepared by the EIM method were more effective for RSV penetration in epidermis and dermis (EDD), with values up to 21% for both penetration enhancers tested. The EIM method, which yielded the best RSV-entrapped niosomes, seems to be the most suitable for scaling up.

Gel-embedded niosomes: preparation, characterization and release studies of a new system for topical drug delivery

In the present paper physical gels, prepared with two polysaccharides, Xanthan and Locust Bean Gum, and loaded with non-ionic surfactant vesicles, are described. The vesicles, composed by Tween20 and cholesterol or by Tween85 and Span20, were loaded with Monoammonium glycyrrhizinate for release experiments. Size and zeta (ζ)-potential of the vesicles were evaluated and the new systems were characterized by rheological and dynamo-mechanical measurements. For an appropriate comparison, a Carbopol gel and a commercial gel for topical applications were also tested. The new formulations showed mechanical properties comparable with those of the commercial product indicating their suitability for topical applications. In vitro release experiments showed that the polysaccharide network protects the integrity of the vesicles and leads to their slow release without disruption of the aggregated structures. Furthermore, being the vesicles composed of molecules possessing enhancing properties, the permeation of the loaded drugs topically delivered can be improved. Thus, the new systems combine the advantages of matrices for a modified release (polymeric component) and those of an easier permeability across the skin (vesicle components). Finally, shelf live experiments indicated that the tested gel/vesicle formulations were stable over 1 year with no need of preservatives.

Nanomedicine strategies for targeting skin inflammation

Topical treatment of skin diseases is an attractive strategy as it receives high acceptance from patients, resulting in higher compliance and therapeutic outcomes. Recently, the use of variable nanocarriers for dermal application has been widely explored, as they offer several advantages compared with conventional topical preparations, including higher skin penetration, controlled and targeted drug delivery and the achievement of higher therapeutic effects. This article will focus on skin inflammation or dermatitis as it is one of the most common skin problems, describing the different types and causes of dermatitis, as well as the typical treatment regimens. The potential use of nanocarriers for targeting skin inflammation and the achievement of higher therapeutic effects using nanotechnology will be explored.

Niosomes from 80s to present: the state of the art

Efficient and safe drug delivery has always been a challenge in medicine. The use of nanotechnology, such as the development of nanocarriers for drug delivery, has received great attention owing to the potential that nanocarriers can theoretically act as "magic bullets" and selectively target affected organs and cells while sparing normal tissues. During the last decades the formulation of surfactant vesicles, as a tool to improve drug delivery, brought an ever increasing interest among the scientists working in the area of drug delivery systems. Niosomes are self assembled vesicular nanocarriers obtained by hydration of synthetic surfactants and appropriate amounts of cholesterol or other amphiphilic molecules. Just like liposomes, niosomes can be unilamellar or multilamellar, are suitable as carriers of both hydrophilic and lipophilic drugs and are able to deliver drugs to the target site. Furthermore, niosomal vesicles, that are usually non-toxic, require less production costs and are stable over a longer period of time in different conditions, so overcoming some drawbacks of liposomes. The niosome properties are specifically dictated by size, shape, and surface chemistry which are able to modify the drug's intrinsic pharmacokinetics and eventual drug targeting to the areas of pathology. This up-to-date review deals with composition, preparation, characterization/evaluation, advantages, disadvantages and application of niosomes.

Ammonium glycyrrhizinate-loaded niosomes as a potential nanotherapeutic system for anti-inflammatory activity in murine models

BACKGROUND

Liquorice extracts demonstrate therapeutic efficacy in treating dermatitis, eczema, and psoriasis when compared with corticosteroids. In this work, nonionic surfactant vesicles (niosomes, NSVs) containing polysorbate 20 (Tween 20), cholesterol, and cholesteryl hemisuccinate at different molar concentrations were used to prepare monoammonium glycyrrhizinate (AG)-loaded NSVs. The anti-inflammatory properties of AG-loaded NSVs were investigated in murine models.

METHODS

The physicochemical properties of the NSVs were characterized using dynamic light scattering. The fluidity of the lipid bilayer was evaluated by measuring the fluorescence intensity of diphenylhexatriene. The drug entrapment efficiency of AG was assessed using high-performance liquid chromatography. The physicochemical stability of the NSVs was evaluated as a function of time using dynamic light scattering combined with Turbiscan Lab Expert analysis. Serum stability was determined by incubating the NSVs with 10% v/v fetal bovine serum. The cytotoxic effects of the NSVs were investigated in human dermal fibroblasts using the Trypan blue dye exclusion assay (for cell mortality) and an MTT assay (for cell viability). Release profiles for the AG-loaded NSVs were studied in vitro using cellulose membranes. NSVs showing the most desirable physicochemical properties were selected to test for in vivo anti-inflammatory activity in murine models. The anti-inflammatory activity of the NSVs was investigated by measuring edema and nociception in mice stimulated with chemical agents.

RESULTS

NSVs showed favorable physicochemical properties for in vitro and in vivo administration. In addition, they demonstrated long-term stability based on Turbiscan Lab Expert analysis. The membrane fluidity of the NSVs was not affected by self-assembling of the surfactants into colloidal structures. Fluorescence anisotropy was found to be independent of the molar ratios of cholesteryl hemisuccinate and/or cholesterol during preparation of the NSVs. The anti-inflammatory AG drug showed no effect on the stability of the NSVs. In vivo experiments demonstrated that AG-loaded NSVs decreased edema and nociceptive responses when compared with AG alone and empty NSVs. In vitro and in vivo results demonstrated that pH sensitive and neutral NSVs show no statistical significant difference.

CONCLUSION

NSVs were nontoxic and showed features favorable for potential administration in vivo. In addition, neutral NSVs showed signs of increased anti-inflammatory and antinociceptive responses when compared with AG.

3-Monoglucuronyl glycyrrhretinic acid is a possible marker compound related to licorice-induced pseudoaldosteronism

One of the most common adverse effects of traditional Japanese kampo and traditional Chinese medicine is pseudoaldosteronism caused by licorice. In this review, the authors describe the mechanisms of licorice-induced pseudoaldosteronism by the pharmacokinetics of chemical constituents and its metabolites containing licorice. Glycyrrhizin (GL), the main constituent of licorice, is absorbed as glycyrrhetinic acid (GA), which is a metabolite of GL produced by enterobacteria before its release into the circulation. Circulating GA is metabolized in the liver to become 3-monoglucuronyl-glycyrrhetinic acid (3MGA), which is excreted into the bile via multidrug resistance protein 2 (Mrp2). If Mrp2 function is damaged for some reason, 3MGA is secreted from the liver into the circulation, and excreted into the urine via organic anion transporters expressed at the basolateral side of tubular epithelial cells. Circulating GA cannot be excreted into the urine since GA binds highly to serum albumin and thus does not pass through glomerular filtration and is not a substrate of transporters expressed on tubular epithelial cells. Licorice-induced pseudoaldosteronism develops due to the inhibition of type 2 11β-hydrosteroid dehydrogenase (11β-HSD2) which results in the accumulation of cortisol in tubular epithelial cells that activate mineral corticoid receptors to stimulate the excretion of potassium that results in hypokalemia. GA, unlike 3MGA, cannot pass through tubular epithelial cells and cannot inhibit the enzyme in the cells. Therefore, 3MGA may be a genuine causative agent for licorice-induced pseudoaldosteronism. When licorice is used, 3MGA in plasma or urine could function as a marker compound to prevent the adverse effects.

Anticancer activity of liposomal bergamot essential oil (BEO) on human neuroblastoma cells

Citrus extracts, particularly bergamot essential oil (BEO) and its fractions, have been found to exhibit anticancer efficacy. However, the poor water solubility, low stability and limited bioavailability have prevented the use of BEO in cancer therapy. To overcome such drawbacks, we formulated BEO liposomes that improved the water solubility of the phytocomponents and increased their anticancer activity in vitro against human SH-SY5Y neuroblastoma cells. The results warrant further investigation of BEO liposomes for in vivo applications.

Non-ionic surfactant vesicles simultaneously enhance antitumor activity and reduce the toxicity of cantharidin

OBJECTIVE

The objective of the present study was to prepare cantharidin-entrapped non-ionic surfactant vesicles (CTD-NSVs) and evaluate their potential in enhancing the antitumor activities and reducing CTD's toxicity.

METHODS AND RESULTS

CTD-NSVs were prepared by injection method. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry analysis showed that CTD-NSVs could significantly enhance in vitro toxicity against human breast cancer cell line MCF-7 and induce more significant cell-cycle arrest in G0/G1 phase. Moreover, Hoechst 33342 staining implicated that CTD-NSVs induced higher apoptotic rates in MCF-7 cells than free CTD solution. In vivo therapeutic efficacy was investigated in imprinting control region mice bearing mouse sarcoma S180. Mice treated with 1.0 mg/kg CTD-NSVs showed the most powerful antitumor activity, with an inhibition rate of 52.76%, which was significantly higher than that of cyclophosphamide (35 mg/kg, 40.23%) and the same concentration of free CTD (1.0 mg/kg, 31.05%). In addition, the acute toxicity and liver toxicity of CTD were also distinctly decreased via encapsulating into NSVs.

CONCLUSION

Our results revealed that NSVs could be a promising delivery system for enhancing the antitumor activity and simultaneously reducing the toxicity of CTD.