A Multiscale Study on the Penetration Enhancement Mechanism of Menthol to Osthole

Ionic Liquid-Based Grapeseed Oil Emulsion for Enhanced Anti-Wrinkle Treatment

OBJECTIVES

To address the poor efficacy and percutaneous penetration of grape seed oil, ionic liquids and nanotechnology were combined to prepare a grape seed oil emulsion.

METHODS

A novel Menthol-CoQ10 ionic liquid and ionic liquid based grapeseed oil emulsion were prepared and confirmed.

RESULTS

The average size of the grapeseed oil emulsion was 218 nm, and its zeta potential was -33.5 mV. The ionic liquid-based grape seed oil emulsion exhibited a transdermal penetration effect 4.63-fold higher than that of ordinary grape seed oil emulsion. Ionic liquid also displayed enhanced efficiency both in vitro and in vivo. It significantly inhibited the production of DPPH free radicals and tyrosinase, inhibited melanin and matrix metalloproteinase-1 (MMP-1) produced by cells, and promoted type I collagen expression in fibroblasts. After 28 days of continuous use, the grapeseed oil emulsion improved the water content of the stratum corneum and the rate of transepidermal water loss, enhanced the firmness and elasticity of the skin, and significantly improved the total number and length of under-eye lines, tail lines, nasolabial folds, and marionette lines on the face.

CONCLUSIONS

Menthol-CoQ10 ionic liquid is a promising functional excipient for both transdermal delivery increase and efficient enhancement. Ionic liquid and nanotechnology for grape seed oil facial mask displayed significantly enhanced efficacy and permeability.

Chinese herbal medicine bath therapy for psoriasis vulgaris using topical calcipotriol as the comparator: A systematic review with meta-analysis and association rule analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a chronic inflammatory skin disease. Vitamin D analogues are the first-line topical agents for the long-term management of psoriasis. Chinese herbal medicine (CHM) bath therapy is commonly employed for psoriasis. However, the effects and safety of CHM bath therapy for psoriasis vulgaris, using topical calcipotriol as the comparator, remain inconclusive. Furthermore, the combination of herbs, a distinctive feature of CHM, is essential for its therapeutic effects due to the individual and synergistic properties of the herbs involved.

AIM OF THE STUDY

The review was conducted to evaluate the effectiveness and safety of CHM bath therapy for psoriasis vulgaris, using calcipotriol as the comparator. Potential herbs and herb combinations of CHM bath therapy were also explored for further drug discovery.

MATERIALS AND METHODS

Nine databases were searched from inception until March 05, 2024. Randomised controlled trials (RCTs) investigating CHM bath therapy, using calcipotriol as the comparator, were included. Statistical analyses were performed using RevMan 5.4, Stata 12.0 and SPSS Clementine 12.0 software. The evidence certainty for outcomes was assessed using the approach proposed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group. Moreover, association rule analysis on herbs identified in the systematic review was conducted to explore the potential herbs and herb combinations.

RESULTS

A total of 17 RCTs involving 1,379 participants were included in this systematic review. The findings of this review revealed that: 1) CHM bath therapy produced comparable effects to calcipotriol in reducing Psoriasis Area and Severity Index (PASI), Psoriasis Scalp Severity Index (PSSI), and itch visual analogue scale (VAS) at the end of the treatment phase; as well as exhibited a superior long-term effect than calcipotriol through decreasing relapse rates at the end of the follow-up phase; 2) CHM bath therapy showed an additional benefit when combined with calcipotriol in managing psoriasis vulgaris at the end of the treatment phase, in terms of PASI, PSSI, itch VAS, IL-17, IL-23, CD3+ and CD4+ T cells. The certainty of the evidence was rated as 'very low', 'low' or 'moderate' based on the GRADE assessment, considering some concerns or high risk of bias of included studies, substantial heterogeneity, and existing publication bias of some outcomes. Additionally, the proportions of participants reporting adverse events were similar in both groups. Association rule analysis of all included herbs identified 23 herb combinations including Prunus persica (L.) Batsch and Carthamus tinctorius L., as well as 11 frequently used herbs, such as Kochia scoparia (L.) Schrad., Dictamnus dasycarpus Turcz. And Sophora flavescens Ait.

CONCLUSIONS

The effects of CHM bath therapy were comparable with those of topical calcipotriol but demonstrated a longer-lasting effect. Combining CHM bath therapy with calcipotriol also provided an additional benefit for adult psoriasis vulgaris. However, the certainty of the evidence was downgraded due to the methodological limitations of included studies. To confirm the findings of this review, future investigations should involve double-blinded, placebo-controlled RCTs. Importantly, it appears worthwhile to consider further research for drug development utilising the identified herbs or herb combinations.

Multifunctional Deep Eutectic Solvent-Based Microemulsion for Transdermal Delivery of Artemisinin

As a serious public health issue, malaria threatens the health of millions of people. Artemisinin, a gift from traditional Chinese medicine, has been used in the treatment of malaria and has shown good therapeutic efficiency. However, due to its low solubility, poor bioavailability, and short half-life time, some smart delivery strategies are still required. Herein, a multifunctional DES prepared from ibuprofen and menthol was prepared. This DES was shown to efficiently promote the solubility of artemisinin up to 400-fold. Then, it was further applied as the oil phase to construct an O/W microemulsion with the help of Tween-80 + Span-20 mixed surfactants. The prepared microemulsion displayed high efficiency in improving the permeability of artemisinin, which can be ascribed to the presence of the permeation enhancer menthol in DES and the microstructure of the O/W microemulsion. Moreover, the simultaneous permeation of artemisinin and ibuprofen further indicated the potential benefits of the presented formulation in the treatment of malaria. To sum up, the microemulsion based on multifunctional DES presented herein provided an effective method for transdermal delivery of artemisinin.

Investigation and Evaluation of the Transdermal Delivery of Ibuprofen in Various Characterized Nano-Drug Delivery Systems

The aim was to assess the suitability of three nano-based transdermal drug delivery systems containing ibuprofen: a nano-emulsion, a nano-emulgel, and a colloidal suspension with ibuprofen-loaded nanoparticles. Understanding the transdermal delivery of ibuprofen using nano-based drug delivery systems can lead to more effective pain relief and improved patient compliance. Characterization tests assessed the suitability of the developed drug delivery systems. Membrane release and skin diffusion studies, along with tape stripping, were performed to determine drug release and skin permeation of ibuprofen. In vitro cytotoxicity studies on HaCaT cells were conducted using MTT and neutral red assays to evaluate the safety of the developed drug delivery systems. Characterization studies confirmed stable drug delivery systems with ideal properties for transdermal delivery. Membrane release studies demonstrated the successful release of ibuprofen. In vitro skin diffusion experiments and tape stripping, detecting ibuprofen in the receptor phase, stratum corneum-epidermis, and epidermis-dermis, indicating successful transdermal and topical delivery. The in vitro cytotoxicity studies observed only minor cytotoxic effects on HaCaT cells, indicating the safety of the developed drug delivery systems. The investigation demonstrated promising results for the transdermal delivery of ibuprofen using the developed drug delivery systems, which contributes to valuable insights that may lead to improved pain management strategies.

Menthol nanoliposomes enhanced anti-tumor immunotherapy by increasing lymph node homing of dendritic cell vaccines

Menthol, a cyclic terpene alcohol, plays a critical role in overcoming the blood-brain barrier and stratum corneum barrier. Herein, we innovatively propose a menthol nanoliposome (Men-nanoLips) that can dramatically increase lymph node accumulation of the dendritic cell (DC)-based anti-tumor vaccines. Specifically, Men-nanoLips efficiently enhanced lymphatic endothelial cell (EC) barrier permeability by reducing the expression of tight junction proteins. And interestingly, Men-nanoLips not only up-regulated the expression of CCR7 in DCs but also increased the secretion of CCL21 in lymphatic ECs. Moreover, Men-nanoLips promoted DC vaccine maturation as evidenced by increasing the expression of costimulatory molecules and up-regulating the pseudopodia-like protein. With those complementary mechanisms provided by Men-nanoLips, the number of the B16 whole-tumor cell lysate-loaded DCs that target the draining LN enhanced remarkably and significantly boosted the treatment efficacy of DC anti-tumor vaccines. Therefore, we concluded that Men-nanoLips could be instructive for increasing LN homing of DC vaccines.

Using molecular simulation to understand the skin barrier

Skin's effectiveness as a barrier to permeation of water and other chemicals rests almost entirely in the outermost layer of the epidermis, the stratum corneum (SC), which consists of layers of corneocytes surrounded by highly organized lipid lamellae. As the only continuous path through the SC, transdermal permeation necessarily involves diffusion through these lipid layers. The role of the SC as a protective barrier is supported by its exceptional lipid composition consisting of ceramides (CERs), cholesterol (CHOL), and free fatty acids (FFAs) and the complete absence of phospholipids, which are present in most biological membranes. Molecular simulation, which provides molecular level detail of lipid configurations that can be connected with barrier function, has become a popular tool for studying SC lipid systems. We review this ever-increasing body of literature with the goals of (1) enabling the experimental skin community to understand, interpret and use the information generated from the simulations, (2) providing simulation experts with a solid background in the chemistry of SC lipids including the composition, structure and organization, and barrier function, and (3) presenting a state of the art picture of the field of SC lipid simulations, highlighting the difficulties and best practices for studying these systems, to encourage the generation of robust reproducible studies in the future. This review describes molecular simulation methodology and then critically examines results derived from simulations using atomistic and then coarse-grained models.

Menthol in Electronic Cigarettes Causes Biophysical Inhibition of Pulmonary Surfactant

With an increasing prevalence of electronic cigarette (e-cigarette) use, especially among youth, there is an urgent need to better understand the biological risks and pathophysiology of health conditions related to e-cigarettes. A majority of e-cigarette aerosols are in the submicron size and would deposit in the alveolar region of the lung, where they must first interact with the endogenous pulmonary surfactant. To date, little is known whether e-cigarette aerosols have an adverse impact on the pulmonary surfactant. We have systematically studied the effect of individual e-cigarette ingredients on an animal-derived clinical surfactant preparation, bovine lipid extract surfactant, using a combination of biophysical and analytical techniques, including in vitro biophysical simulations using constrained drop surfactometry, molecular imaging with atomic force microscopy, chemical assays using carbon nuclear magnetic resonance and circular dichroism, and in silico molecular dynamics simulations. All data collectively suggest that flavorings used in e-cigarettes, especially menthol, play a predominant role in inhibiting the biophysical function of the surfactant. The mechanism of biophysical inhibition appears to involve menthol interactions with both phospholipids and hydrophobic proteins of the natural surfactant. These results provide novel insights into the understanding of the health impact of e-cigarettes and may contribute to a better regulation of e-cigarette products.

Enhanced skin retention and permeation of a novel peptide via structural modification, chemical enhancement, and microneedles

Hyperpigmentation is a common skin condition with serious psychosocial consequences. Decapeptide-12, a novel peptide, has been found to be safer than hydroquinone in reducing melanin content, with efficacy up to more than 50% upon 16 weeks of twice-daily treatment. However, the peptide suffers from limited transcutaneous penetration due to its hydrophilicity and high molecular weight. Therefore, decapeptide-12 was modified by adding a palmitate chain in an attempt to overcome this limitation. Molecular docking results showed that the two peptides exhibited similar biological activity towards tyrosinase. We also tested the effect of chemical penetration enhancers and microneedles to deliver the two peptides into and through skin, using an in vitro human skin permeation method. It was shown that the palm-peptide achieved the best skin retention owing to the increased lipophilicity. In addition, skin permeation of the palm-peptides was enhanced by the chemical skin penetration enhancers, namely, oleic acid and menthol. Skin permeation of the native peptide was enhanced by the microneedle patch but not the chemical skin penetration enhancers. Cutaneous absorption of the palm-peptides was estimated to have achieved its therapeutic concentration within skin. The combinatory approach of using molecular modification, chemical penetration enhancement, and microneedle patch proves to be useful to enhanceskin permeation of the peptides.

The application of label-free imaging technologies in transdermal research for deeper mechanism revealing

The penetration behavior of topical substances in the skin not only relates to the transdermal delivery efficiency but also involves the safety and therapeutic effect of topical products, such as sunscreen and hair growth products. Researchers have tried to illustrate the transdermal process with diversified theories and technologies. Directly observing the distribution of topical substances on skin by characteristic imaging is the most convincing approach. Unfortunately, fluorescence labeling imaging, which is commonly used in biochemical research, is limited for transdermal research for most topical substances with a molecular mass less than 500 Da. Label-free imaging technologies possess the advantages of not requiring any macromolecular dyes, no tissue destruction and an extensive substance detection capability, which has enabled rapid development of such technologies in recent years and their introduction to biological tissue analysis, such as skin samples. Through the specific identification of topical substances and endogenous tissue components, label-free imaging technologies can provide abundant tissue distribution information, enrich theoretical and practical guidance for transdermal drug delivery systems. In this review, we expound the mechanisms and applications of the most popular label-free imaging technologies in transdermal research at present, compare their advantages and disadvantages, and forecast development prospects.

The Evaluations of Menthol and Propylene Glycol on the Transdermal Delivery System of Dual Drug-Loaded Lyotropic Liquid Crystalline Gels

This study aimed to evaluate the effects of two different structural alcohol permeation enhancers (menthol and propylene glycol) on the internal structure and in vitro properties of the dual drug-loaded lyotropic liquid crystalline (LLC) gels. The LLC gels were prepared and characterized by polarized light microscopy, small-angle X-ray scattering, differential scanning calorimetry, attenuated total reflectance-Fourier transform infrared spectrum, and rheology. Based on the results, the inner structure of the gels was Q_II mesophase and exhibited a pseudoplastic fluid behavior. The level of internal order in the LLC mesophase would be affected by introduced 2 wt% menthol (MEN) and propylene glycol (PG). The in vitro release experiment showed that the release behavior of sinomenine hydrochloride (SH) and cinnamaldehyde (CA) from the LLC system was dominated by Fickian diffusion (n < 0.43). MEN and PG had the opposite effects on the release of hydrophilic SH, while the MEN and PG both increased the release of lipophilic drug CA. Furthermore, in vitro permeation studies indicated that MEN and PG could both improve the skin permeability of SH and CA, and MEN displayed more pronounced enhancement. All the samples showed no skin irritation on the normal rat skin. Collectively, in our research, monoterpenoid MEN exhibited a better penetration-promoting effect than straight-chain fatty alcohol PG on the dual drug-loaded LLC system.

Bromocoumarinplatin, targeting simultaneously mitochondria and nuclei with p53 apoptosis pathway to overcome cisplatin resistance

Mitochondria as one of potential anticancer target, alternatively damaging mtDNA other than nDNA is a potential method for platinum-based anticancer drugs to overcome cisplatin resistance. We herein report that bromocoumarinplatin 1, a coumarin-Pt(IV) prodrug, targeted simultaneously mitochondria and nuclei with the contents of Pt in nDNA and mtDNA were 25.75% and 65.91%, respectively, which demonstrated mtDNA apoptosis played a key role in overcoming cisplatin resistance. Moreover, 1 promoted the expression of p53 gene and protein more effectively than cisplatin, leading to the increased anticancer activity of 1 through p53 pathway. The property of preferential accumulation in cancer cells (Snu-368 and Snu-739) compared to the matched normal cells (HL-7702 cells) demonstrated that 1 was potentially safe for clinical therapeutic use. In addition, the higher therapeutic indices of 1 for HCT-116 cells in vivo indicated that bromocoumarinplatin behaved a vital function in the treatment of colon cancer.

Permeation-enhancing effects and mechanisms of borneol and menthol on ligustrazine: A multiscale study using in vitro and coarse-grained molecular dynamics simulation methods

Borneol (BO) and menthol (MEN) are two widely used natural permeation enhancers in the transdermal drug delivery system. In previous studies, their permeation enhancement effects and mechanisms of action on the hydrophobic drug osthole (logP = 3.8) and hydrophilic drug 5-fluorouracil (logP = -0.9) have been studied. In this study, ligustrazine (LTZ), whose logP is 1.3, was used as a model drug to provide a comprehensive understanding of the influence of its logP on the permeation-enhancing effects of BO and MEN. Both BO and MEN enhanced the permeation of LTZ through the skin stratum corneum, as determined using the modified Franz diffusion cell experiment. The enhancement mechanisms were illustrated by coarse-grained molecular dynamics simulations as follows: at low concentrations, the enhancing ratio of MEN was higher than that of BO because of the stronger perturbation effects of MEN on the lipid bilayer, making it looser and facilitating LTZ diffusion. However, at high concentrations, in addition to the diffusion mechanism, BO induced the formation of water channels to improve the permeation of LTZ; however, MEN had no significant effects through this mechanism. Their results were different from those found with osthole and 5-fluorouracil and have been discussed in this study.