Optical Coherence Tomography and Microdialysis for Microneedle-Mediated Penetration Enhancement Study of Paeoniflorin-Loaded Ethosomes

State-of-the-art strategies to enhance the mechanical properties of microneedles

Microneedles (MNs) have gained increasing attention in the biomedical field, owing to their notable advantages over injectable and transdermal preparations. The mechanical properties of MNs are the key to determine whether MNs can puncture the skin for efficient drug delivery and therapeutic purposes. However, there is still lacking of a systemic summary on how to improve the mechanical property of MNs. Herein, this review mainly analyzes the key factors affecting the mechanical properties of MNs from the theoretical point of view and puts forward improvement approaches. First, we analyzed the major stresses exerted on the MNs during skin puncture and described general methods to evaluate the mechanical properties of MNs. We then provided detail examples to elucidate how the physicochemical properties of single polymer, formulation compositions, and MNs geometric parameters affected the mechanical properties of MNs. Overall, the mechanical strength of MNs can be enhanced by tuning the crosslinking density, crystallinity degree, and molecular weight of single polymer, introducing polysaccharides, and nano-microparticles as reinforcers to form complex with polymer, and optimizing MNs geometric parameters. Therefore, this review will provide critical guidance on how to fabricate MNs with robust mechanical strength for successful transdermal drug delivery.

Evaluation of drug interactions of Saposhnikoviae Radix and its major components with astragaloside IV and paeoniflorin using in vitro and in vivo experiments

Saposhnikoviae Radix (SR) may enhance the pharmacodynamics of Huangqi Chifeng Tang (HQCFT) in the treatment of cerebral infarction according to our previous research, but the underlying mechanism is unknown. Herein, an in vivo pharmacokinetic assay in rats and in vitro MDCK-MDR1 cell assays were used to investigate the possible mechanism of SR, its main components, and its interactions with Astragali Radix (AR) and Paeoniae Radix (PR). An ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC‒MS/MS)-based analytical method for quantifying astragaloside IV (ASIV) and paeoniflorin (PAE) in microdialysis and transport samples was developed. The pharmacokinetic parameters of SR were determined using noncompartmental analyses CCK-8 assays were used to detect the cytotoxicity of ASIV, PAE, cimifugin (CIM), prim-o-glucosylcimifugin (POG) and their combinations. Moreover, drug transport was studied using MDCK-MDR1 cells. Western blotting was performed to measure the protein expression levels of P-GP and MRP1. Claudin-5, ZO-1, and F-actin expression was determined via immunohistochemical staining of MDCK-MDR1 cells. harmacokinetic studies revealed that, compared with those of Huangqi Chifeng Tang-Saposhnikoviae Radix (HQCFT-SR), the Tmax of ASIV increased by 11.11 %, and the MRT0-t and Tmax of PAE increased by 11.19 % and 20 %, respectively, in the HQCFT group. Transport studies revealed that when ASIV was coincubated with 28 μM CIM or POG, the apparent permeability coefficient (Papp) increased by 71.52 % and 50.33 %, respectively. Coincubation of PAE with 120 μM CIM or POG increased the Papp by 87.62 % and 60.95 %, respectively. Moreover, CIM and POG significantly downregulated P-gp and MRP1 (P < 0.05), inhibited the expression of Claudin-5, ZO-1, and F-actin (P < 0.05), and affected intercellular tight junctions (TJs). In conclusion, our study successfully established a selective, sensitive and reproducible UPLC‒MS/MS analytical method to detect drug‒drug interactions between SR, AR and PR in vivo and in vitro, which is beneficial for enhancing the therapeutic efficacies of AR and PR. Moreover, this study provides a theoretical basis for further research on the use of SR as a drug carrier.

Genus Paeonia monoterpene glycosides: A systematic review on their pharmacological activities and molecular mechanisms

BACKGROUND

Genus Paeonia, which is the main source of Traditional Chinese Medicine (TCM) Paeoniae Radix Rubra (Chishao in Chinese), Paeoniae Radix Alba (Baishao in Chinese) and Moutan Cortex (Mudanpi in Chinese), is rich in active pharmaceutical ingredient such as monoterpenoid glycosides (MPGs). MPGs from Paeonia have extensive pharmacological effects, but the pharmacological effects and molecular mechanisms of MPGs has not been comprehensively reviewed.

PURPOSE

MPGs compounds are one of the main chemical components of the genus Paeonia, with a wide variety of compounds and strong pharmacological activities, and the structure of the mother nucleus-pinane skeleton is similar to that of a cage. The purpose of this review is to summarize the pharmacological activity and mechanism of action of MPGs from 2012 to 2023, providing reference direction for the development and utilization of Paeonia resources and preclinical research.

METHODS

Keywords and phrases are widely used in database searches, such as PubMed, Web of Science, Google Scholar and X-Mol to search for citations related to the new compounds, extensive pharmacological research and molecular mechanisms of MPGs compounds of genus Paeonia.

RESULTS

Modern research confirms that MPGs are the main compounds in Paeonia that exert pharmacological effects. MPGs with extensive pharmacological characteristics are mainly concentrated in two categories: paeoniflorin derivatives and albiflflorin derivatives among MPGs, which contains 32 compounds. Among them, 5 components including paeoniflorin, albiflorin, oxypaeoniflorin, 6'-O-galloylpaeoniflorin and paeoniflorigenone have been extensively studied, while the other 28 components have only been confirmed to have a certain degree of anti-inflammatory and anticomplementary effects. Studies of pharmacological effects are widely involved in nervous system, endocrine system, digestive system, immune system, etc., and some studies have identified clear mechanisms. MPGs exert pharmacological activity through multilateral mechanisms, including anti-inflammatory, antioxidant, inhibition of cell apoptosis, regulation of brain gut axis, regulation of gut microbiota and downregulation of mitochondrial apoptosis, etc. CONCLUSION: This systematic review delved into the pharmacological effects and related molecular mechanisms of MPGs. However, there are still some compounds in MPGs whose pharmacological effects and pharmacological mechanisms have not been clarified. In addition, extensive clinical randomized trials are needed to verify the efficacy and dosage of MPGs.

Preparation of paeoniflorin-glycyrrhizic acid complex transethosome gel and its preventive and therapeutic effects on melasma

Paeoniflorin (PF) and glycyrrhizic acid (GL) have skin beautifying effects of anti-inflammation, anti-oxidation, inhibition of melanin formation, and reduction of skin pigmentation. To improve the transdermal permeability of PF and GL in transdermal drug delivery system (TDDS) and enhance their anti-melasma efficacy, PF-GL transethosome (PF-GL-TE) was prepared by ethanol injection method, and finally gelled with carbomer-940 to form PF-GL-TE gel. Consequently, the obtained PF-GL-TE is small and uniform, with an average particle size and a PDI value of about 167.9 nm and 0.102. PF-GL-TE gel showed sustained release behavior and high transdermal permeability in vitro release and transdermal tests. Meanwhile, PF-GL-TE gel played significant preventive effects on melasma induced by progesterone injection and ultraviolet radiation B (UVB) irradiation. According to the results of H&E staining and Masson staining of rat skin, PF-GL-TE gel can alleviate the skin inflammation of and reduce the loss of collagen fibers of back skin in the melasma model rats. Compared with the PF-GL mixture gel, PF-GL-TE gel significantly attenuated the oxidative damage of liver and skin by increasing the activity of SOD and reducing the content of MDA. The results of Western blot showed that PF-GL-TE gel might down-regulate melanin-related proteins expressions of MITF/TYR/TRP1 and TRP2 to prevent and treat melasma. These findings indicate that PF-GL-TE gel is an effective TDDS for delivering PF and GL into the skin, providing a promising preparation for effective prevention and treatment of melasma.

Promising Strategies for Transdermal Delivery of Arthritis Drugs: Microneedle Systems

Arthritis is a general term for various types of inflammatory joint diseases. The most common clinical conditions are mainly represented by rheumatoid arthritis and osteoarthritis, which affect more than 4% of people worldwide and seriously limit their mobility. Arthritis medication generally requires long-term application, while conventional administrations by oral delivery or injections may cause gastrointestinal side effects and are inconvenient for patients during long-term application. Emerging microneedle (MN) technology in recent years has created new avenues of transdermal delivery for arthritis drugs due to its advantages of painless skin perforation and efficient local delivery. This review summarizes various types of arthritis and current therapeutic agents. The current development of MNs in the delivery of arthritis drugs is highlighted, demonstrating their capabilities in achieving different drug release profiles through different self-enhancement methods or the incorporation of nanocarriers. Furthermore, the challenges of translating MNs from laboratory studies to the clinical practice and the marketplace are discussed. This promising technology provides a new approach to the current drug delivery paradigm in treating arthritis in transdermal delivery.

Correlation between in vivo microdialysis pharmacokinetics and ex vivo permeation for sinomenine hydrochloride transfersomes with enhanced skin absorption

Transdermal drug delivery systems have drawn increasing attention in recent decades. Estimation of the correlation between ex vivo permeation and in vivo absorption (EVIVC) is an indispensable issue in the research and development of transdermal pharmaceutical products. In this paper, sinomenine hydrochloride (SH) transfersomes (SHTs) were prepared with sodium deoxycholate as edge activator, while SH liposomes (SHLs) were prepared as a control preparation. The transdermal permeation characteristics differences between them were explored by an ex vivo skin permeation experiment with Franz diffusion cell and an in vivo skin/blood pharmacokinetic experiment facilitated by double-sited microdialysis sampling technique. The curves of percentage absorbed versus time (absorption curves) under the skin and in the blood were plotted according to the percentages calculated by the deconvolution approach with the application of Wagner-Nelson model, and were correlated with the ex vivo permeation curves to evaluate a level A correlation, while a level C correlation evaluation was conducted based on the in vivo steady-state blood concentration (C_ss) and the ex vivo steady-state transdermal permeation rate. The ex vivo permeation test indicated that the cumulative transdermal permeated amount of SH at 36 h in SHTs was about 1.7 times of that in SHLs. The skin pharmacokinetic data showed that the C_ss and AUC_0-t of SHTs were about 8.8 and 8.0 times of those of SHLs, respectively, and the MRT_0-t of SHTs was shorter. The blood pharmacokinetic data showed that the C_ss and AUC_0-t of SHTs were about 3.7 and 2.9 times of those of SHLs, respectively. The in vivo absorption curves were correlated well with the ex vivo permeation curves. The squares of correlation coefficient (R²) for SHTs and SHLs were 0.9153 and 0.9355 respectively in the skin, were 0.8536 and 0.7747 respectively in the blood. As to level C EVIVC, there was no significant difference between the predicted C_ss from ex vivo and the measured C_ssin vivo. The transfersomes can be employed as effective vehicles to promote the transdermal absorption of SH, and it is feasible to predict the in vivo skin/blood pharmacokinetic properties of SHLs and SHTs based on the ex vivo skin permeation characteristics.

PF-PLC micelles ameliorate cholestatic liver injury via regulating TLR4/MyD88/NF-κB and PXR/CAR/UGT1A1 signaling pathways in EE-induced rats

Paeoniflorin (PF) has a certain therapeutic effect on cholestasis liver injury. To further improve the bioavailability of PF and play its pharmacological role in liver protection, PF-phospholipid complex micelles (PF-PLC micelles) were prepared based on our previous research on PF-PLC. The protective effects of PF and PF-PLC micelles on cholestasis liver injury induced by 17α-ethynylestradiol (EE) were compared, and the possible mechanisms were further explored. Herein, we showed that PF-PLC micelles effectively improved liver function, alleviated liver pathological damage, and localized infiltration of inflammatory cells. Mechanism studies indicated that PF-PLC micelles treatment could suppress the TLR4/MyD88/NF-κB pathway, and further reduce the levels of pro-inflammatory factors. Meanwhile, our experimental results demonstrated that the beneficial effect of PF-PLC micelles on EE-induced cholestasis may be achieved by the upregulation of nuclear receptors and metabolic enzymes (PXR/CAR/UGT1A1). All these results indicate that PF-PLC micelles have great potential in the treatment of cholestatic liver disease.