Enhanced effect and mechanism of water-in-oil microemulsion as an oral delivery system of hydroxysafflor yellow A

Volatile Oil of Magnolia biondii Pamp. for Transnasal Administration: Its Preparation, Characterization, and Mechanism of Action in the Treatment of Allergic Rhinitis

BACKGROUND

Allergic Rhinitis (AR) is a common chronic nasal condition usually caused by allergens. The immune system overreacts when the body is exposed to allergens, releasing a lot of tissue chemicals that cause congestion, more secretions, and an inflammatory reaction in the nasal mucosa.

METHOD

In clinical practice, it remains a significant public health issue. Modern pharmacological studies have demonstrated that Magnolia Volatile Oil (MVO) has good anti-inflammatory, antibacterial, immunomodulatory, and other pharmacological effects. Previous research and literature reports have reported that MVO has good therapeutic effects on allergic rhinitis. However, due to the poor water solubility of Magnolia, its bioavailability is low. The purpose of this present work is to develop a new microemulsion formulation to improve the stability and bioavailability of MVO.

RESULTS

The droplet size, PDI, and zeta potential of Magnolia volatile oil microemulsion (MVOME) were characterized along with its physical characteristics, and these values were found to be 14.270.03 nm, 0.09410.31, and -0.35850.12 mV, respectively, demonstrating the successful formation of microemulsion. In OVA-induced AR rats, MVO-ME dramatically reduced the serum levels of TNF-α, IL-1β, and IL-6 inflammatory factors. In addition, MVO-ME significantly inhibited the expression of protein levels of PPAR-γ and P65 in the nasal mucosa of AR rats. In this regard, we hypothesized that MVO-ME may play a therapeutic role in AR by activating the PPAR signaling pathway as well as inhibiting the activation of the NF/κB signaling pathway.

CONCLUSION

MVO-ME has systematic advantages, such as high solubility, bioavailability, etc. It is expected to be an efficient nano-drug delivery system for the clinical treatment of allergic rhinitis.

Nanoemulsions of Hydroxysafflor Yellow A for Enhancing Physicochemical and In Vivo Performance

Stroke was always a disease that threatened human life and health worldwide. We reported the synthesis of a new type of hyaluronic acid-modified multi-walled carbon nanotube. Then, we produced hydroxysafflor yellow A-hydroxypropyl-β-cyclodextrin phospholipid complex water-in-oil nanoemulsion with hyaluronic acid-modified multi-walled carbon nanotubes and chitosan (HC@HMC) for oral treatment of an ischemic stroke. We measured the intestinal absorption and pharmacokinetics of HC@HMC in rats. We found that the intestinal absorption and the pharmacokinetic behavior of HC@HMC was superior to that of HYA. We measured intracerebral concentrations after oral administration of HC@HMC and found that more HYA crossed the blood-brain barrier (BBB) in mice. Finally, we evaluated the efficacy of HC@HMC in middle cerebral artery occlusion/reperfusion (MCAO/R)-injured mice. In MCAO/R mice, oral administration of HC@HMC demonstrated significant protection against cerebral ischemia-reperfusion injury (CIRI). Furthermore, we found HC@HMC may exert a protective effect on cerebral ischemia-reperfusion injury through the COX2/PGD2/DPs pathway. These results suggest that oral administration of HC@HMC may be a potential therapeutic strategy for the treatment of stroke.

Bioactive Loaded Novel Nano-Formulations for Targeted Drug Delivery and Their Therapeutic Potential

Plant-based medicines have received a lot of attention in recent years. Such medicines have been employed to treat medical conditions since ancient times, and in those times only the observed symptoms were used to determine dose accuracy, dose efficacy, and therapy. Rather than novel formulations, the current research work on plant-based medicines has mostly concentrated on medicinal active phytoconstituents. In the past recent decades, however, researchers have made significant progress in developing "new drug delivery systems" (NDDS) to enhance therapeutic efficacy and reduce unwanted effects of bioactive compounds. Nanocapsules, polymer micelles, liposomes, nanogels, phytosomes, nano-emulsions, transferosomes, microspheres, ethosomes, injectable hydrogels, polymeric nanoparticles, dendrimers, and other innovative therapeutic formulations have all been created using bioactive compounds and plant extracts. The novel formulations can improve solubility, therapeutic efficacy, bioavailability, stability, tissue distribution, protection from physical and chemical damage, and prolonged and targeted administration, to name a few. The current study summarizes existing research and the development of new formulations, with a focus on herbal bioactive components.

Short-wave and near infrared π-conjugated polymers hosted in a biocompatible microemulsion: a pioneering approach for photoacoustic contrast agents

In the present study a biocompatible oil-in-water (O/W) microemulsion was developed carrying short-wave infrared (SWIR) π-conjugated polymers and possessing photoacoustic properties for the first time. SWIR and NIR absorbing conjugated polymers were accomplished to be dissolved in a Food & Drug Administration (FDA) approved natural oil limonene, to formulate an O/W microemulsion using biocompatible surfactants (Span80, Labrasol®). Detailed structural characterization in the absence and presence of the polymers was performed by means of dynamic light scattering (DLS), small-angle X-ray scattering (SAXS) and electron paramagnetic resonance (EPR) spectroscopy. In terms of biological evaluation of the loaded microemulsions, inhibition of cell proliferation in various cancer cell lines without exhibiting significant cytotoxicity was tested through the MTT assay. The developed π-conjugated polymers hosted in O/W microemulsions represent a technological approach with a wide range of biomedical and bioelectronic applications and in this contribution, their photoacoustic properties are presented as a proof-of-concept.

Pharmacological Actions, Molecular Mechanisms, Pharmacokinetic Progressions, and Clinical Applications of Hydroxysafflor Yellow A in Antidiabetic Research

Hydroxysafflor yellow A (HSYA), a nutraceutical compound derived from safflower (Carthamus tinctorius), has been shown as an effective therapeutic agent in cardiovascular diseases, cancer, and diabetes. Our previous study showed that the effect of HSYA on high-glucose-induced podocyte injury is related to its anti-inflammatory activities via macrophage polarization. Based on the information provided on PubMed, Scopus and Wanfang database, we currently aim to provide an updated overview of the role of HSYA in antidiabetic research from the following points: pharmacological actions, molecular mechanisms, pharmacokinetic progressions, and clinical applications. The pharmacokinetic research of HSYA has laid foundations for the clinical applications of HSYA injection in diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy. The application of HSYA as an antidiabetic oral medicament has been investigated based on its recent oral delivery system research. In vivo and in vitro pharmacological research indicated that the antidiabetic activities of HSYA were based mainly on its antioxidant and anti-inflammatory mechanisms via JNK/c-jun pathway, NOX4 pathway, and macrophage differentiation. Further anti-inflammatory exploration related to NF-κB signaling, MAPK pathway, and PI3K/Akt/mTOR pathway might deserve attention in the future. The anti-inflammatory activities of HSYA related to diabetes and diabetic complications will be a highlight in our following research.

Hydroxysafflor yellow A, a natural compound from Carthamus tinctorius L with good effect of alleviating atherosclerosis

BACKGROUND

Atherosclerosis is a chronic vascular inflammatory disease with complex pathogenesis. Its serious consequence is insufficient blood supply to heart and brain, which eventually leads to myocardial ischemia, infarction and stroke. Hydroxysafflor yellow A (HSYA), a single chalcone glycoside compound with a variety of pharmacological effects, which has shown a potential biological activity for prevention and treatment of atherosclerosis.

PURPOSE

The main purpose of this review is to comprehensively elucidate the mechanism of HSYA on atherosclerosis and its risk factors (hyperlipidemia, hypertension and diabetes mellitus).

METHOD

The literatures on HSYA in the treatment of atherosclerosis and its risk factors were searched in PubMed, Google Scholar, China National Knowledge Infrastructure, including in vitro (cell), in vivo (animal) and clinical (human) studies, and summarized reasonably.

RESULTS

HSYA is a promising natural product for treating atherosclerosis. It can suppress foam cell formation, vascular endothelial cell dysfunction, vascular smooth muscle cell proliferation and migration, and platelet activation. The mechanisms are achieved by regulating the reverse cholesterol transport process, fatty acid synthesis, oxidative stress, PI3K/Akt/mTOR, NLRP3 inflammasome, TNFR1/NF-κB, NO-cGMP, Bax/Bcl-2, MAPKs, CDK/CyclinD and TLR4/Rac1/Akt signaling pathways. Besides, HSYA is devoted to lowering blood lipids, regulating ion channels, reducing vascular inflammation, and protecting pancreatic beta cells, which is conducive to reducing the harm of independent risk factors of atherosclerosis.

CONCLUSIONS

HSYA exhibits the preventive and therapeutic effects on atherosclerosis and its risk factors in vivo and in vitro, which is relevant to multiple mechanisms. The clinical trials of HSYA need to be further investigated to provide a solid foundation for its clinical application.

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.

Bioactive Substances in Safflower Flowers and Their Applicability in Medicine and Health-Promoting Foods

Safflower flowers (Carthamus tinctorius) contain many natural substances with a wide range of economic uses. The most famous dye isolated from flower petals is hydroxysafflor A (HSYA), which has antibacterial, anti-inflammatory, and antioxidant properties. This review is aimed at updating the state of knowledge about their applicability in oncology, pulmonology, cardiology, gynecology, dermatology, gastrology, immunology, and suitability in the treatment of obesity and diabetes and its consequences with information published mainly in 2018-2020. They were also effective in treating obesity and diabetes and its consequences. The issues related to the possibilities of using HSYA in the production of health-promoting food were also analyzed.

Hydroxysafflor Yellow A: A Systematical Review on Botanical Resources, Physicochemical Properties, Drug Delivery System, Pharmacokinetics, and Pharmacological Effects

Hydroxysafflower yellow A (HSYA), as a principal natural ingredient extracted from safflower (Carthamus tinctorius L.), has significant pharmacological activities, such as antioxidant, anti-inflammatory, anticoagulant, and anticancer effects. However, chemical instability and low bioavailability have been severely hampering the clinical applications of HSYA during the treatment of cardiovascular and cerebrovascular disease. Therefore, this present review systematically summarized the materials about HSYA, including acquisition methods, extraction and detection methods, pharmacokinetics, pharmacological effects and molecular mechanism, especially focus on the possible causes and resolutions about the chemical instability and low bioavailability of HSYA, in order to provide relatively comprehensive basic data for the related research of HSYA.

Therapeutic Potential of Hydroxysafflor Yellow A on Cardio-Cerebrovascular Diseases

The incidence rate of cardio-cerebrovascular diseases (CCVDs) is increasing worldwide, causing an increasingly serious public health burden. The pursuit of new promising treatment options is thus becoming a pressing issue. Hydroxysafflor yellow A (HSYA) is one of the main active quinochalcone C-glycosides in the florets of Carthamus tinctorius L., a medical and edible dual-purpose plant. HSYA has attracted much interest for its pharmacological actions in treating and/or managing CCVDs, such as myocardial and cerebral ischemia, hypertension, atherosclerosis, vascular dementia, and traumatic brain injury, in massive preclinical studies. In this review, we briefly summarized the mode and mechanism of action of HSYA on CCVDs based on these preclinical studies. The therapeutic effects of HSYA against CCVDs were presumed to reside mostly in its antioxidant, anti-inflammatory, and neuroprotective roles by acting on complex signaling pathways.

Novel Drug Delivery Systems for Loading of Natural Plant Extracts and Their Biomedical Applications

Many types of research have distinctly addressed the efficacy of natural plant metabolites used for human consumption both in cell culture and preclinical animal model systems. However, these in vitro and in vivo effects have not been able to be translated for clinical use because of several factors such as inefficient systemic delivery and bioavailability of promising agents that significantly contribute to this disconnection. Over the past decades, extraordinary advances have been made successfully on the development of novel drug delivery systems for encapsulation of plant active metabolites including organic, inorganic and hybrid nanoparticles. The advanced formulas are confirmed to have extraordinary benefits over conventional and previously used systems in the manner of solubility, bioavailability, toxicity, pharmacological activity, stability, distribution, sustained delivery, and both physical and chemical degradation. The current review highlights the development of novel nanocarrier for plant active compounds, their method of preparation, type of active ingredients, and their biomedical applications.

Antifungal activity of 2'-hydroxychalcone loaded in nanoemulsion against Paracoccidioides spp

Aim: This study aimed to evaluate the activity of 2'-hydroxychalcone-loaded in nanoemulsion (NLS + 2'chalc), the cytotoxic effect and toxicity against Paracoccidioides brasiliensis and Paracoccidioides lutzii using a zebrafish model. Materials & methods: Preparation and physical-chemical characterization of nanoemulsion (NLS) and NLS + 2'chalc were performed. MIC and minimum fungicide concentration, cytotoxicity and toxicity were also evaluated in the Danio rerio model. Results: NLS + 2'chalc showed fungicidal activity against Paracoccidioides spp. without cytotoxicity in MRC5 and HepG2 lines. It also had high selectivity index values and no toxicity in the zebrafish model based on MIC values. Conclusion: NLS + 2'chalc is a potential new alternative treatment for paracoccidioidomycosis.

Oil-In-Water Microemulsions as Hosts for Benzothiophene-Based Cytotoxic Compounds: An Effective Combination

Targeted delivery of chemotherapeutics in order to overcome side effects and enhance chemosensitivity remains a major issue in cancer research. In this context, biocompatible oil-in-water (O/W) microemulsions were developed as matrices for the encapsulation of DPS-2 a benzothiophene analogue, exhibiting high cytotoxicity in various cancer cell lines, among them the MW 164 skin melanoma and Caco-2 human epithelial colorectal adenocarcinoma cell lines. The microemulsion delivery system was structurally characterized by dynamic light scattering (DLS) and electron paramagnetic resonance (EPR) spectroscopy. The effective release of a lipophilic encapsulated compound was evaluated via confocal microscopy. The cytotoxic effect, in the presence and absence of DPS-2, was examined through the thiazolyl blue tetrazolium bromide (MTT) cell proliferation assay. When encapsulated, DPS-2 was as cytotoxic as when dissolved in dimethyl sulfoxide (DMSO). Hence, the oil cores of O/W microemulsions were proven effective biocompatible carriers of lipophilic bioactive molecules in biological assessment experiments. Further investigation through fluorescence-activated cell sorting (FACS) analysis, comet assay, and Western blotting, revealed that DPS-2, although non-genotoxic, induced S phase delay accompanied by cdc25A degradation and a nonapoptotic cell death in both cell lines, which implies that this benzothiophene analogue is a deoxyribonucleic acid (DNA) replication inhibitor.

Nanoemulsion-based delivery system for enhanced oral bioavailability and caco-2 cell monolayers permeability of berberine hydrochloride

Berberine hydrochloride (BBH) has a variety of pharmacological activities such as antitumor, antimicrobial, anti-inflammation, and reduce irritable bowel syndrome. However, poor stability and low oral bioavailability limited its usage. Herein, an oil-in-water nanoemulsion system of BBH was developed to improve its stability and oral bioavailability. The pseudoternary phase diagrams were constructed for the determination of composition of various nanoemulsions. The nanoemulsions of BBH composed of Labrafil M 1944 CS (oil phase), RH-40 (surfactant), glycerin (co-surfactant), and water (aqueous phase). The O/W nanoemulsion of BBH showed a relative bioavailability of 440.40% compared with unencapsulated BBH and was stable in our 6-month stability study. Further, there was a significant increase in intestinal permeability of BBH as assessed by Caco-2 cell monolayers and a significant reduction in efflux of BBH by the multidrug efflux pump P-glycoprotein. This study confirmed that the nanoemulsion formulation could be used as an alternative oral formulation of BBH to improve its stability, oral bioavailability and permeability.

Improving In Vivo Efficacy of Bioactive Molecules: An Overview of Potentially Antitumor Phytochemicals and Currently Available Lipid-Based Delivery Systems

Cancer is among the leading causes of morbidity and mortality worldwide. Many of the chemotherapeutic agents used in cancer treatment exhibit cell toxicity and display teratogenic effect on nontumor cells. Therefore, the search for alternative compounds which are effective against tumor cells but reduce toxicity against nontumor ones is of great importance in the progress or development of cancer treatments. In this sense, scientific knowledge about relevant aspects of nutrition intimately involved in the development and progression of cancer progresses rapidly. Phytochemicals, considered as bioactive ingredients present in plant products, have shown promising effects as potential therapeutic/preventive agents on cancer in several in vitro and in vivo assays. However, despite their bioactive properties, phytochemicals are still not commonly used in clinical practice due to several reasons, mainly attributed to their poor bioavailability. In this sense, new formulation strategies are proposed as carriers to improve their bioefficacy, highlighting the use of lipid-based delivery systems. Here, we review the potential antitumoral activity of the bioactive compounds derived from plants and the current studies carried out in animal and human models. Furthermore, their association with lipids as a formulation strategy to enhance their efficacy in vivo is also reported. The development of high effective bioactive supplements for cancer treatment based on the improvement of their bioavailability goes through this association.

Drug nanocarriers for cancer chemotherapy based on microemulsions: The case of Vemurafenib analog PLX4720

Oil-in-water (O/W) microemulsions based on Tween 80 as the emulsifier and triacetin as the dispersed oil phase were formulated to be used as delivery vehicles of Vemurafenib analog PLX4720. PLX4720 is a lipophilic antitumor drug against various cancer types correlated with the BRAF^V600E mutation. The limits of the single-phase region corresponding to O/W microemulsions as described by ternary phase diagrams were examined. Droplet size measurements determined by dynamic light scattering (DLS) showed mean droplet diameters equal to 10±0.1nm both in the presence and in absence of the drug. Cryogenic-transmission electron microscopy (Cryo-TEM) images of the microemulsions showed the existence of small structures with uniform size distribution having also average diameters of approximately 10nm. Electron paramagnetic resonance (EPR) spectroscopy applying the spin probing technique confirmed PLX4720 location in the oil cores excluding its participation in the surfactants monolayer. Furthermore, cell viability assays on colon cancer cell lines Colo-205 and HT29 showed that microemulsions did not exhibit any cytotoxicity when added in ratios between 0.005% v/v and 0.2% v/v. When the cells were treated with encapsulated PLX4720 at two different concentrations (0.063 and 0.12μΜ) the same response as when dissolved in classic DMSO was observed.

Preparation and evaluation of microemulsion‑based transdermal delivery of Cistanche tubulosa phenylethanoid glycosides

The primary aim of the present study was to develop a novel microemulsion (ME) formulation to deliver phenylethanoid glycoside (PG) for use in skin lighteners and sunscreens. The oil phase was selected on the basis of drug solubility, while the surfactant and cosurfactant were screened and selected on the basis of their solubilizing capacity and the efficiency with which they formed MEs. Pseudoternary phase diagrams were constructed to evaluate ME regions and five formulations of oil-in-water MEs were selected as vehicles. In vitro skin permeation experiments were performed to optimize the ME formulation and to evaluate its permeability in comparison to that of saline solution. The physicochemical properties of the optimized ME and the permeating ability of PG delivered by this ME were also investigated. The optimized ME formulation was composed of isopropyl myristate (7%, w/w), Cremorphor EL (21%, w/w), propylene glycol (7%, w/w) and water (65%, w/w). The cumulative amount of PG that permeated through excised mouse skin when carried by ME was ~1.68 times that when PG was carried by saline solution only. The cumulative amount of PG in the microemulsion (4149.650±37.3 µg·cm⁻²) was significantly greater than that of PG in the saline solution (2288.63±20.9 µg·cm⁻²). Furthermore, the permeability coefficient indicated that optimized microemulsion was a more efficient carrier for transdermal delivery of PG than the control solution (8.87±0.49 cm/hx10⁻³ vs. 5.41±0.12 cm/hx10⁻³). Taken together, the permeating ability of ME-carried PG was significantly increased compared with saline solution.

In vivo fate of lipid-based nanoparticles

The in vivo fate of lipid-based nanoparticles (LBNs) is essentially determined by the properties of their lipid compositions. LBNs are rapidly degraded via lipolysis wherever lipases are abundant, especially in the gastrointestinal tract. LBNs that survive lipolysis can be translocated through the circulation to reach terminal organs or tissues. Lipid composition, particle size, and surface decoration, as well as the formation of protein corona, are the main factors influencing the in vivo fate of LBNs. As we discuss here, elucidation of the in vivo fate of LBNs helps weigh the balance between lipolysis and biorecognition, and is emerging as a new field of research.

Hydroxysafflor yellow A exerts antioxidant effects in a rat model of traumatic brain injury

Free radical-induced oxidative damage occurs rapidly and is of primary importance during the secondary pathophysiological cascades of traumatic brain injury (TBI). Hydroxysafflor yellow A (HSYA) is a constituent of the flower petals of Carthamus tinctorius (safflower) and may represent a potential therapeutic strategy to improve outcomes following TBI. The present study aimed to identify HSYA in the brain tissues of rats exposed to TBI to determine its absorption and to investigate the underlying effects of HSYA on antioxidant enzymes in the brain tissues of TBI rats. To determine the absorption of HSYA for the investigation of the underlying antioxidant effects of HSYA in TBI, the presence of HSYA in the brain tissues of the TBI rats was identified using an ultra performance liquid chromatography-tandem mass spectrometry method. Subsequently, the state of oxidative stress in the TBI rat model following the administration of HSYA was investigated by determining the levels of antioxidant enzymes, including superoxide dismutase (SOD), malondialdehyde (MDA) and catalase (CAT), and the ratio of glutathione (GSH)/glutathione disulfide (GSSG). The data obtained demonstrated that HSYA was absorbed in the brain tissues of the TBI rats. HSYA increased the activities of SOD and CAT, the level of GSH and the GSH/GSSG ratio. However, HSYA concomitantly decreased the levels of MDA and GSSG. These preliminary data suggest that HSYA has the potential to be utilized as a neuroprotective drug in cases of TBI.

Improved oral bioavailability of poorly water-soluble glimepiride by utilizing microemulsion technique

The objective of this work was to prepare an oil/water glimepiride (GM) microemulsion (ME) for oral administration to improve its solubility and enhance its bioavailability. Based on a solubility study, pseudoternary phase diagrams, and Box–Behnken design, the oil/water GMME formulation was optimized and prepared. GMME was characterized by dynamic laser light scattering, zeta potential, transmission electron microscopy, and viscosity. The in vitro drug release, storage stability, pharmacodynamics, and pharmacokinetics of GMME were investigated. The optimized GMME was composed of Capryol 90 (oil), Cremophor RH40 (surfactant), and Transcutol (cosurfactant), and increased GM solubility up to 544.6±4.91 µg/mL. The GMME was spherical in shape. The particle size and its polydispersity index were 38.9±17.46 nm and 0.266±0.057, respectively. Meanwhile, the GMME was physicochemically stable at 4°C for at least 3 months. The short-term efficacy in diabetic mice provided the proof that blood glucose had a consistent and significant reduction at a dose of 375 µg/kg whether via IP injection or IG administration of GMME. Compared with the glimepiride suspensions or glimepiride-meglumine complex solution, the pharmacokinetics of GMME in Wistar rats via IG administration exhibited higher plasma drug concentration, larger area under the curve, and more enhanced oral bioavailability. There was a good correlation of GMME between the in vitro release values and the in vivo oral absorption. ME could be an effective oral drug delivery system to improve bioavailability of GM.

Nanocarriers for the delivery of active ingredients and fractions extracted from natural products used in traditional Chinese medicine (TCM)

Traditional Chinese medicine (TCM) has been practiced for thousands of years with a recent increase in popularity. Despite promising biological activities of active ingredients and fractions from TCM, their poor solubility, poor stability, short biological half-life, ease of metabolism and rapid elimination hinder their clinical application. Therefore, overcoming these problems to improve the therapeutic efficacy of TCM preparations is a major focus of pharmaceutical sciences. Recently, nanocarriers have drawn increasing attention for their excellent and efficient delivery of active TCM ingredients or fractions. This review discusses problems in the delivery of active TCM ingredients or fractions; focuses on recent advances in nanocarriers that represent potential solutions to these problems, including lipid-based nanoparticles and polymeric, inorganic, and hybrid nanocarriers; and discusses unanswered questions in the field and criteria for the development of better nanocarriers for the delivery of active TCM ingredients or fractions to be focused on in future studies.

Biocompatible colloidal dispersions as potential formulations of natural pyrethrins: a structural and efficacy study

Biocompatible colloidal dispersions of the micro- and nanoemulsion type based on lemon oil terpenes, polysorbates, water, and glycerol were used for the formulation of pyrethrins, botanical insecticides derived from the white pyrethrum daisy, Tanacetum cinerariifolium. The proposed formulation is based on pyrethrin-containing water-in-oil (W/O) microemulsions that could be diluted in one step with an aqueous phase to obtain kinetically stable oil-in-water (O/W) nanoemulsions. Structural characteristics of the micro- and nanoemulsions were evaluated by electron paramagnetic resonance (EPR) spectroscopy, dynamic light scattering (DLS), small angle X-ray scattering (SAXS), and electrical conductivity. Dynamic properties of the surfactant monolayer as evidenced by EPR measurements were affected by the water content, the surfactant, and also the presence of the biocide. DLS and SAXS experiments of the nanoemulsions indicated the existence of two populations of oil droplets dispersed in the aqueous phase, globular droplets of 36-37 nm in diameter, and also larger droplets with diameters >150 nm. All of the applied techniques for structural determination revealed the participation of the biocide in the nanostructure. The insecticidal effect of the encapsulated natural pyrethrin was evaluated in laboratory bioassays upon a target-insect pest, the cotton aphid Aphis gossypii Glover (Hemiptera: Aphididae) in eggplant, and was found to be increased compared to the commercial pyrethrin formulation.

Emulsion-based colloidal nanosystems for oral delivery of doxorubicin: improved intestinal paracellular absorption and alleviated cardiotoxicity

We have previously reported that the limited intestinal absorption via the paracellular pathway may be the primary cause of the low oral bioavailability of doxorubicin (DOX). In this study, we have formulated medium chain glycerides-based colloidal nanosystems to enhance the intestinal paracellular absorption of DOX and reduce its cardiotoxicity. The DOX formulations prepared by the construction of pseudo-ternary phase diagram were characterized in terms of their droplet size distribution, viscosity, drug loading, and drug release. Further evaluation was conducted by an in vitro Caco-2 transport study as well as in situ/in vivo intestinal absorption, bioavailability and toxicity studies. Compared with DOX solution, these formulations enhanced the absorptive transport of DOX across Caco-2 cell monolayers at least partly due to the paracellular-enhancing effects of their lipidic components. Moreover, the in situ intestinal absorption and in vivo oral bioavailability of DOX in rats were markedly enhanced. In addition, no discernible damage was observed in the rat jejunum after oral administration of these DOX formulations while the cardiac toxicity was significantly reduced when compared with intravenous DOX solution. Taken together, the medium chain glycerides-based colloidal nanosystems prepared in this study represent a potentially effective oral delivery system for DOX.

Chemical and biological properties of quinochalcone C-glycosides from the florets of Carthamus tinctorius

Quinochalcone C-glycosides are regarded as characteristic components that have only been isolated from the florets of Carthamus tinctorius. Recently, quinochalcone C-glycosides were found to have multiple pharmacological activities, which has attracted the attention of many researchers to explore these compounds. This review aims to summarize quinochalcone C-glycosides’ physicochemical properties, chromatographic behavior, spectroscopic characteristics, as well as their biological activities, which will be helpful for further study and development of quinochalcone C-glycosides.

Mechanisms of microemulsion enhancing the oral bioavailability of puerarin: comparison between oil-in-water and water-in-oil microemulsions using the single-pass intestinal perfusion method and a chylomicron flow blocking approach

The purpose of the present work was to determine the mechanisms by which microemulsions (MEs) enhance the oral bioavailability of puerarin. The in situ perfusion method was used in rats to study the absorption mechanisms of an oil-in-water (O/W) microemulsion (O/W-ME) and a water-in-oil (W/O) microemulsion (W/O-ME). The possibility of lymphatic transport of the MEs was investigated using a chylomicron flow blocking approach. The results for the absorption mechanisms in the stomach and intestines indicated that the absorption characteristics of the O/W-ME and W/O-ME depend on the segment. The W/O-ME had higher internal membrane permeability than the O/W-ME. The results of the lymphatic transport analyses showed that both the O/W-ME and W/O-ME underwent lymphatic transport and that this pathway was a major contributor to the oral bioavailability of MEs. Furthermore, the type of ME can significantly affect the absorption of puerarin through the lymphatic system due to the oil content and the form of the microemulsion after oral administration. In conclusion, these data indicate that microemulsions are an effective and promising delivery system to enhance the oral bioavailability of poorly water-soluble drugs.

Mechanism of enhanced oral absorption of hydrophilic drug incorporated in hydrophobic nanoparticles

Hydroxysafflor yellow A (HSYA) is an effective ingredient of the Chinese herb Carthamus tinctorius L, which has high water solubility and low oral bioavailability. This research aims to develop a hydrophobic nanoparticle that can enhance the oral absorption of HSYA. Transmission electron microscopy and freeze-fracture replication transmission election microscopy showed that the HSYA nanoparticles have an irregular shape and a narrow size distribution. Zonula occludens 1 protein (ZO–1) labeling showed that the nanoparticles with different dilutions produced an opening in the tight junctions of Caco-2 cells without inducing cytotoxicity to the cells. Both enhanced uptake in Caco-2 cells monolayer and increased bioavailability in rats for HSYA nanoparticles indicated that the formulation could improve bioavailability of HSYA significantly after oral administration both in vitro and in vivo.