Cyclodextrins-in-Liposomes: A Promising Delivery System for Lippia sidoides and Syzygium aromaticum Essential Oils

Advances in plant essential oils and drug delivery systems for skincare

Background

Essential oils, often referred to as "liquid gold," are renowned for their broad biological activity. Ancient Egyptians used essential oils' antibacterial and antiseptic effects to preserve mummies, ancient Greeks used olive oil for sun protection, and ancient Chinese used essential oils to treat wounds. When essential oils are applied to the facial skin, their potent anti-inflammatory, antioxidant, and antibacterial pharmacological characteristics provide various benefits, including sunscreen, skin-whitening, and anti-aging effects.

Purpose

This paper aims to summarize the application of plant essential oil in skin whitening, anti-inflammatory, antioxidant and antibacterial in recent years, and deeply analyzes the internal relationship between essential oil and modern drug delivery system, expounds how to overcome the limitations of essential oil through specific drug delivery system, to enhance its biological activity and stability, realize sustained release and reduce its potential toxicity, and also discusses the positive effects of essential oil on brain function through olfactory pathway, emphasizes the possible safety risks in the use of essential oil, and puts forward corresponding suggestions for use.

Methods

Using keywords such as "essential oils," "antioxidant," "anti-tyrosinase," Antibacterial Effects and anti-inflammatory," "anti-anxiety," and "drug carrier delivery systems," a comprehensive search was conducted in the PubMed, CNKI, Baidu, and Wanfang databases to summarize articles from the past 5 years. Further screening was performed to select studies demonstrating the efficacy of essential oils through topical or external application.

Results

Various essential oils showed their efficacy as strong oxidants, antibacterial agents, anti-inflammatory agents, and skin-whitening agents. Combined with a new drug delivery system, it not only enhances the biological activity of essential oil but also reduces the inherent defects of essential oil, such as volatility, irritation, and toxicity, and has a targeted delivery effect. At the same time, the integration of essential oil into skin care products can make use of the dual functions of smell and the epidermal system to nourish and repair the skin and maximize the pharmacological effects of essential oil.

Conclusion

This review delves into the application of essential oils and delivery systems, advocating for a broader integration of natural plant resources with modern technology. By strategically utilizing essential oils, we can promote the sustainable development of the global economy. However, extensive clinical trials are still required to evaluate the effectiveness and safety of essential oil delivery systems.

Recent progress in the source, extraction, activity mechanism and encapsulation of bioactive essential oils

There is growing concern about the potential risks posed by synthetic additives in industrial products, such as foods, cosmetics, agrochemicals, and personal care products. Many plant-derived essential oils (EOs) have been shown to exhibit excellent antibacterial, antifungal, antiviral, and antioxidant activities, and may therefore be used as natural preservatives in these applications. However, most EOs have relatively low water solubility and are prone to chemical degradation during storage. The degradation products of EOs can be toxic and may not be able to fully exert their biological activity, which limits their application. Typically, these challenges can be overcome by encapsulating the essential oil in an appropriate colloid delivery system. This article begins by reviewing the sources, extraction, and activity mechanisms of EOs, and then highlights plant-based encapsulation technologies that can be used to enhance their efficacy. Finally, the potential applications of plant essential oil encapsulation system are discussed.

Insights from Syzygium aromaticum Essential Oil: Encapsulation, Characterization, and Antioxidant Activity

Alginate encapsulates loaded with clove essential oil (CEO) were prepared by ionic gelation, with subsequent freeze-drying. The objective of the present work was to develop a product with the ability to protect CEO against its easy volatility and oxidation. The following techniques were used to characterize the formulations: eugenol release, degree of swelling, GC/MS, TGA/DSC, and SEM. The alginate solution (1.0%) containing different concentrations of CEO (LF1: 1.0%; LF2: 0.5%; LF3: 0.1%) was dropped into a 3.0% CaCl2 solution. After lyophilization, the encapsulated samples were wrinkled and rigid, with high encapsulation power (LF3: 76.9% ± 0.5). Three chemical components were identified: eugenol (the major one), caryophyllene, and humulene. The antioxidant power (LF1: DPPH IC50 18.1 µg mL-1) was consistent with the phenol content (LF1: 172.2 mg GAE g-1). The encapsulated ones were thermally stable, as shown by analysis of FTIR peaks, eugenol molecular structure was kept unaltered. The degree of swelling was 19.2% (PBS). The release of eugenol (92.5%) in the PBS solution was faster than in the acidic medium. It was concluded that the low-cost technology used allows the maintenance of the content and characteristics of CEO in the three concentrations tested, offering a basis for further research with essential oil encapsulates.

Development and Efficacy Evaluation of Innovative Cosmetic Formulations with Caryocar brasiliense Fruit Pulp Oil Encapsulated in Freeze-Dried Liposomes

Encapsulation and drying technologies allow the engineering of innovative raw materials from plant biodiversity, with potential applications in pharmaceutical and cosmetic fields. Lipid-based nanoencapsulation stands out for its efficiency, ease of production, and versatility in encapsulating substances, whether hydrophilic or lipophilic. This work aimed at encapsulating pequi oil in liposomes and freeze-dried liposomes to enhance its stability and functional benefits, such as skin hydration and anti-aging effects, for use in innovative cosmetic formulations. Pequi oil-extracted from the Caryocar brasiliense fruit pulp, a plant species from Brazilian plant biodiversity-is rich in secondary metabolites and fatty acids. Liposomes and dried liposomes offer controlled production processes and seamless integration into cosmetic formulations. The physicochemical analysis of the developed liposomes confirmed that the formulations are homogeneous and electrokinetically stable, as evidenced by consistent particle size distribution and zeta potential values, respectively. The gel-type formulations loaded with the dried liposomes exhibit enhanced skin hydration, improved barrier function, and refined microrelief, indicating improvements in skin conditions. These results highlight the potential of dried liposomes containing pequi oil for the development of innovative cosmeceutical products. This research contributes to the valorization of Brazilian biodiversity by presenting an innovative approach to leveraging the dermatological benefits of pequi oil in cosmetic applications.

Novel nano-encapsulated limonene: Utilization of drug-in-cyclodextrin-in-liposome formulation to improve the stability and enhance the antioxidant activity

Drug-in-cyclodextrin-in-liposome (DCL) combines advantages of cyclodextrin and liposome. Here, DCL formulation was successfully prepared to encapsulate limonene (Lim), whose characterization revealed that particle size was 147.5 ± 1.3 nm and zeta potential was -48.7 ± 0.8 mV. And the complexation mechanism of Lim/HP-β-CD inclusion complex (the intermediate of DCL) was analyzed by molecular dynamics simulation, showing that Lim was entrapped into the cavity of HP-β-CD through electrostatic and hydrophobic interaction with a molar ratio of 1:1. Notably, DCL formulation not only reduced Lim volatilization in 25℃, but also enhanced the free radical (DPPH· and ABTS·+) scavenging ability of Lim. In summary, Lim-DCL formulation improved the stability and enhanced the antioxidant activity of Lim. DCL nanocarrier system is suitable to preserve volatile and hydrophobic compounds, enlarging their application in pharmaceutics industries.

The Protective Effects of Moisturizer Containing Potentilla anserina Extract in the Topical Treatment of Skin Damage Caused by Masks

The use of face masks during the COVID-19 pandemic resulted in significant societal changes, particularly for individuals with sensitive skin. To address this issue, the researchers explored traditional medicine and identified Potentilla anserina extract as a potential solution due to its anti-inflammatory and moisturizing effects. This research investigated how this extract influences skin hydration, barrier function, and itching. The findings revealed that the extract had a hydrating effect by elevating Aquaporin-3 (AQP3) expression. Additionally, the study demonstrated that the extract improved skin barrier function, with Filaggrin (FLG) expression being approximately three times higher (p < 0.001) in the Potentilla-anserina-extract-treated group compared to the control group and the genes associated with itching being reduced. In this process, we researched and developed HPβCD (hydroxypropyl-β-cyclodextrin)-Liposome containing Potentilla anserina extract, gradually and sustainably releasing the active components of the Potentilla anserina extract. During four weeks of clinical trials involving individuals wearing masks for over 6 h a day, a moisturizer containing Potentilla anserina extract demonstrated a notable reduction in skin redness. Hemoglobin values (A.U.), which serve as indicators of skin redness, showed decreases of 5.06% and 6.74% in the test area inside the mask after 2 and 4 weeks, respectively, compared to the baseline measurements. Additionally, the moisturizer containing Potentilla anserina extract notably decreased Trans Epidermal Water Loss (TEWL), with reductions of 5.23% and 9.13% observed in the test area inside the mask after 2 and 4 weeks, respectively. The moisturizer, especially in the test area treated with the extract-containing moisturizer, significantly enhanced skin hydration compared to the control group. The Corneometer values (A.U) exhibited notable increases of 11.51% and 15.14% in the test area inside the mask after 2 and 4 weeks, respectively. These discoveries emphasize the potential of Potentilla anserina extract and its utility in tackling skin issues caused by mask wearing, including enhancing moisture, fortifying the skin's barrier, and alleviating itching. These results indicate that moisturizers incorporating specific ingredients provide greater benefits compared to conventional moisturizers.

Development of Liposome Systems for Enhancing the PK Properties of Bivalent PROTACs

Proteolysis-Targeting Chimeras (PROTACs) are a promising new technology in drug development. They have rapidly evolved in recent years, with several of them in clinical trials. While most of these advances have been associated with monovalent protein degraders, bivalent PROTACs have also entered clinical trials, although progression to market has been limited. One of the reasons is the complex physicochemical properties of the heterobifunctional PROTACs. A promising strategy to improve pharmacokinetics of highly lipophilic compounds, such as PROTACs, is encapsulation in liposome systems. Here we describe liposome systems for intravenous administration to enhance the PK properties of two bivalent PROTAC molecules, by reducing clearance and increasing systemic coverage. We developed and characterized a PROTAC-in-cyclodextrin liposome system where the drug was retained in the liposome core. In PK studies at 1 mg/kg for GNE-01 the PROTAC-in-cyclodextrin liposome, compared to the solution formulation, showed a 80- and a 380-fold enhancement in AUC for mouse and rat studies, respectively. We further investigated the same PROTAC-in-cyclodextrin liposome system with the second PROTAC (GNE-02), where we monitored both lipid and drug concentrations in vivo. Similarly, in a mouse PK study of GEN-02, the PROTAC-in-cyclodextrin liposome system exhibited enhancement in plasma concentration of a 23× increase over the conventional solution formulation. Importantly, the lipid CL correlated with the drug CL. Additionally, we investigated a conventional liposome approach for GNE-02, where the PROTAC resides in the lipid bilayer. Here, a 5× increase in AUC was observed, compared to the conventional solution formulation, and the drug CL was faster than the lipid CL. These results indicate that the different liposome systems can be tailored to translate across multiple PROTAC systems to modulate and improve plasma concentrations. Optimization of the liposomes could further improve tumor concentration and improve the overall therapeutic index (TI). This delivery technology may be well suited to bring novel protein targeted PROTACs into clinics.

Development, application and future trends of starch-based delivery systems for nutraceuticals: A review

As a natural biopolymer, starch is ideally adapted as an encapsulant material for nutraceutical delivery systems due to its unique nature of extensive sources, versatility and high biocompatibility. This review offers an outline of recent advances in the development of starch-based delivery systems. The structure and functional properties of starch in encapsulating and delivering bioactive ingredients are first introduced. Structural modification of starch improves the functionalities and extends the applications of starch in novel delivery systems. Then, various nutraceutical delivery systems are systematically summarized, which include porous starch, starch particle, amylose inclusion complex, cyclodextrin, gel, edible film and emulsion. Next, the delivery process of nutraceuticals is discussed in two parts: digestion and release. Intestinal digestion plays an important role during the whole digestion process of starch-based delivery systems. Moreover, controlled release of bioactives can be achieved by porous starch, starch-bioactive complexation and core-shell structure. Finally, the challenges of the existing starch-based delivery systems are deliberated, and the directions for future research are pointed out. Composite delivery carriers, co-delivery, intelligent delivery, delivery in real food systems, and reuse of agricultural wastes may be the research trends for starch-based delivery systems in the future.

Antioxidant Therapy as an Effective Strategy against Noise-Induced Hearing Loss: From Experimental Models to Clinic

Cochlear redox unbalance is the main mechanism of damage involved in the pathogenesis of noise-induced-hearing loss. Indeed, the increased free radical production, in conjunction with a reduced efficacy of the endogenous antioxidant system, plays a key role in cochlear damage induced by noise exposure. For this reason, several studies focused on the possibility to use exogenous antioxidant to prevent or attenuate noise-induce injury. Thus, several antioxidant molecules, alone or in combination with other compounds, have been tested in both experimental and clinical settings. In our findings, we tested the protective effects of several antioxidant enzymes, spanning from organic compounds to natural compounds, such as nutraceuticals of polyphenols. In this review, we summarize and discuss the strengths and weaknesses of antioxidant supplementation focusing on polyphenols, Q-Ter, the soluble form of CoQ10, Vitamin E and N-acetil-cysteine, which showed great otoprotective effects in different animal models of noise induced hearing loss and which has been proposed in clinical trials.

Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline

Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.

Royal Jelly Components Encapsulation in a Controlled Release System—Skin Functionality and Biochemical Activity for Skin Applications

Royal jelly is a yellowish-white substance with a gel texture that is secreted from the hypopharyngeal and mandibular glands of young worker bees. It consists mainly of water (50–56%), proteins (18%), carbohydrates (15%), lipids (3–6%), minerals (1.5%), and vitamins, and has many beneficial properties such as antimicrobial, anti-inflammatory, anticancer, antioxidant, antidiabetic, immunomodulatory, and anti-aging. Royal jelly has been used since ancient times in traditional medicine, cosmetics and as a functional food due to its high nutritional value. The main bioactive substances are royalactin, and 10-hydroxy-2-decenoic acid (10-HDA). Other important bioactive molecules with antioxidant and photoprotective skin activity are polyphenols. However, they present difficulties in extraction and in use as they are unstable physicochemically, and a higher temperature causes color change and component degradation. In the present study, a new encapsulation and delivery system consisting of liposomes and cyclodextrins incorporating royal jelly has been developed. The new delivery system aims to the elimination of the stability disadvantages of royal jelly’s sensitive component 10-HDA, but also to the controlled release of its ingredients and, more particularly, 10-HDA, for an enhanced bioactivity in cosmeceutical applications.