Preparation Of Nanoemulsions Research Articles

Preparation of lutein nanoemulsion by ultrasonic homogenization method: Stability and in vitro anti-inflammatory activity

Lutein is a natural antioxidant that has anti-inflammatory activity; thus, lutein-enriched anti-inflammatory agents have the potential for development. Nanoemulsions represent an effective molecular liquid for improving the solubility and stability of lutein. The oil and surfactant components, preparation method and preparation conditions are highly related to the stability and biological activity of nanoemulsions. In this study, lutein nanoemulsions were prepared by the ultrasonic homogenization method, the components and preparation conditions were optimized by the response surface methodology, and the final preparation conditions were confirmed. The contents of medium chain triglyceride (MCT) and Tween 80 were 1.5 wt% and 11 wt%, respectively, and the ultrasonic time was 8.5 min. The anti-inflammatory activities and long-term stability of the prepared lutein nanoemulsion were then evaluated. Lutein affected the secretion levels of interleukin-6 (IL-6), interleukin-10 (IL-10) and monocyte chemotactic and activating factor (MCAF), especially IL-6 and MCAF. On Day 28, the lutein retention rates of lutein nanoemulsion with Propyl gallate (PG) at 4 °C, 25 °C and 37 °C were 97.75 ± 0.43 %, 75.77 ± 0.45 % and 47.72 ± 0.19 %, respectively. The addition of PG greatly improved the retention rate of lutein and the particle size stability of the lutein nanoemulsion at high temperature (37 °C). The current results demonstrated the potential utilization of lutein emulsion as anti-inflammatory agents.

Sterically Stabilized Diblock Copolymer Nanoparticles Enable Efficient Preparation of Non-Aqueous Pickering Nanoemulsions.

We report the first example of a non-aqueous Pickering nanoemulsion, which comprises glycerol droplets dispersed in mineral oil. The droplet phase is stabilized by hydrophobic sterically stabilized poly(lauryl methacrylate)-poly(benzyl methacrylate) nanoparticles which are prepared directly in mineral oil using polymerization-induced self-assembly. First, a glycerol-in-mineral oil Pickering macroemulsion with a mean droplet diameter of 2.1 ± 0.9 μm is prepared via high-shear homogenization using excess nanoparticles as an emulsifier. Then, this precursor macroemulsion is subjected to high-pressure microfluidization (a single pass at an applied pressure of 20,000 psi) to produce glycerol droplets of approximately 200-250 nm diameter. Transmission electron microscopy studies indicate preservation of the distinctive superstructure produced by nanoparticle adsorption at the glycerol/mineral oil interface, thus confirming the Pickering nature of the nanoemulsion. Glycerol is sparingly soluble in mineral oil, thus such nanoemulsions are rather susceptible to destabilization via Ostwald ripening. Indeed, substantial droplet growth occurs within 24 h at 20 °C, as judged by dynamic light scattering. However, this problem can be suppressed by dissolving a non-volatile solute (sodium iodide) in glycerol prior to formation of the nanoemulsion. This reduces diffusional loss of glycerol molecules from the droplets, with analytical centrifugation studies indicating much better long-term stability for such Pickering nanoemulsions (up to 21 weeks). Finally, the addition of just 5% water to the glycerol phase prior to emulsification enables the refractive index of the droplet phase to be matched to that of the continuous phase, leading to relatively transparent nanoemulsions.

Analysis of Phenolic Acids and Flavonoids in Rabbiteye Blueberry Leaves by UPLC-MS/MS and Preparation of Nanoemulsions and Extracts for Improving Antiaging Effects in Mice.

Rabbiteye blueberry leaves, a waste produced after harvest of blueberry, are rich in polyphenols. This study aims to analyze phenolic acids and flavonoids in blueberry leaves by UPLC-MS/MS and prepare nanoemulsions for determining anti-aging activity in mice. Overall, 30% ethanol was the most suitable extraction solvent for total phenolic acids and total flavonoids. A total of four phenolic acids and four flavonoids were separated within seven minutes for further identification and quantitation by UPLC-MS/MS in selective reaction monitoring (SRM) mode, with 3-O-caffeoylquinic acid being present in the highest amount (6474.2 μg/g), followed by quercetin-3-O-galactoside (1943.9 μg/g), quercetin-3-O-rutinoside (1036.6 μg/g), quercetin-3-O-glucoside (867.2 μg/g), 5-O-caffeoylquinic acid (815.8 μg/g), kaempferol-3-O-glucoside (309.7 μg/g), 3,5-dicaffeoylquinic acid (195.3 μg/g), and 4,5-dicaffeoylquinic acid (60.8 μg/g). The blueberry nanoemulsion was prepared by using an appropriate ratio of soybean oil, Tween 80, glycerol, ethanol, and water at 1.2%, 8%, 2%, 2%, and 86.8%, respectively, and mixing with dried blueberry extract, with the mean particle size and zeta potential being 16 nm and -54 mV, respectively. A high stability was observed during storage of nanoemulsion for 90 days at 4 °C and heated at 100 °C for 2 h. An animal study revealed that this nanoemulsion could elevate dopamine content in mice brain as well as superoxide dismutase, glutathione peroxidase, and catalase activities in mice liver while reducing the contents of malondialdehyde and protein carbonyl in mice brains. Collectively, the high-dose nanoemulsion possessed the highest efficiency in improving mice aging with a promising potential for development into a health food.

Preparation of cinnamaldehyde nanoemulsions: Formula optimization, antifungal activity, leaf adhesion, and safety assessment

Plant essential oils have become an increasingly popular topic in agriculture due to their outstanding fungicidal activity, good biocompatibility and abundance of sources. Cinnamaldehyde is found in cinnamon essential oil and has good antifungal activity, but cinnamaldehyde also has negative characteristics such as high volatility, poor water solubility and easy oxidative degradation, which seriously hinder the potential of its antimicrobial properties and its application in agriculture. In this study, the effects of the surfactant ratio, concentration and emulsification method on the stability of cinnamaldehyde nanoemulsions were systematically investigated by observing the sample appearance, mean droplet size and differential scanning calorimetry (DSC) analysis. The results showed that the optimal formula of cinnamaldehyde nanoemulsion was a surfactant (R5:848) ratio of 1:1 and a concentration of 7%, and the emulsification method was E1: adding dropwise aqueous phase (deionized water) to the oil phase (cinnamaldehyde + surfactant). Cinnamaldehyde nanoemulsions showed good antifungal activity against rice sheath blight (Rhizoctonia solani), wheat sheath blight (Rhizoctonia cerealis) and wheat take-all (Gaeumannomyces graminis). The nanoemulsions also had excellent wetting properties on rice and wheat leaves, higher biosafety for nontarget environmental organisms such as zebrafish and earthworms, low cytotoxicity to human BASE-2B cells, and no inhibition of germination and growth of wheat and rice. The results of this research provide important ideas for the design of efficient, safe and environmentally friendly plant-derived fungicides.

Spontaneous Emulsification of Citronella Oil: Effect of Processing Conditions and Production Scale

Nanoemulsions are gaining considerable interest for use in delivery of essential oil-based pesticides. Evaluation in the laboratory have shown promising efficacy of nanobiopesticides, and further development in nanoemulsion production at larger scale is needed for a wider application in the field. This study aimed to evaluate the changes in droplet size characteristics of citronella oil nanoemulsions produced using spontaneous emulsification at increased scales. The preparation of nanoemulsion was carried out in two stages of scale-up, namely the laboratory scale (200–1000 mL) and the larger scale (10–50 L). The process variables included stirring speed and time. Characterization was done on the oil droplet size, polydispersity index (PDI), zeta potential and microscopic structure. The oil droplet size, PDi and zeta potential varied with the emulsification process conditions and the production scale. In general, increasing mixing speed and time tended to decrease droplet size and PDI, and increase zeta potential. The changes in characteristics of nanoemulsion were minor at the higher production scales. Relatively small droplet sizes were found in the whole experiment (90–160 nm) with PDI of 0.2 – 0.4 and zeta potential of -28 to -8.8 mV. These results are useful for the design of nanoemulsion production at practical application scale.

Nano-Emulsion Based Gel for Topical Delivery of an Anti-Inflammatory Drug: In vitro and in vivo Evaluation.

Arthritic disorder is a common disease in elderly patients and the most common cause of joint dysfunction. This study aims to design Piroxicam-loaded nanoemulsion (PXM-NE) formulations to enhance the analgesic and anti-inflammatory activity of the drug for topical use. The nanoemulsion preparations were designed based on a high-pressure homogenization technique and were characterized for particle size (PS), poly dispersity index (Pi), zeta potential (ZP), drug content, and the selected formula was investigated for its topical analgesic activity and pharmacokinetic parameters. The characterizations showed that the PS was 310.20±19.84 nm, Pi was 0.15±0.02, and ZP was -15.74±1.6 mV for the selected formula. A morphology study showed that the PXM-NE droplets were spherical with a uniform size distribution. The in vitro release study showed a biphasic release pattern with a rapid release within the first 2 hours followed by a sustained release pattern. The analgesic activity for optimal formula was 1.66 times higher than the commercial gel with a double duration of analgesic activity. The Cmax was 45.73±9.95 and 28.48±6.44 ng/mL for the gel form of the selected formula and the commercial gel respectively. The relevant bioavailability of the selected formula was 2.41 higher than the commercial gel. The results showed good physicochemical properties, higher bioavailability, and a longer analgesic effect of PXM from nanoemulsion gel, as compared to the commercial product.

One-Step Preparation of Luteolin Nanoemulsion and Evaluation of its Anti-inflammatory Effect in Animal Models.

Nanoemulsions are promising drug delivery systems for topical application owing to the high transdermal penetration. Due to the side effects of existing anti-inflammatory drugs, much attention has been paid to natural products such as flavonoids. The aim of this work was to formulate luteolin nanoemulsion (LNE) and to evaluate its anti-inflammatory effect. LNE was prepared using the low-energy spontaneous emulsion method and characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). The anti-inflammatory effect of LNE was assessed in formalin and acetic acid-induced inflammation methods (Whittle test). Treatment with LNE (i.p, 4 consecutive days, 40 mg/kg) was compared with diclofenac 25 mg/kg and normal saline. In the formalin test, data were recorded at 1, 2 and 4 hours after formalin injection and in the Wittle test, the extent of Evans blue leakage in the peritoneal cavity was considered as vascular permeability. Formalin-induced edema decreased in the LNE group, but this reduction was not significant (p > 0.05), however, in Whittle test, both LNE and diclofenac significantly reduced Evans blue leakage compared with the group treated with acetic acid alone (p < 0.05). Our results confirm the anti-inflammatory effect of LNE and give up a new platform for the design and development of bio-based carriers for more successful drug delivery.

Formulasi dan Evaluasi Sediaan Nanoemulsi Ekstrak Umbi Bawang Putih (Allium sativum L.)

Garlic bulbs (Allium sativum L.) has an active substance in the form of allicin which is thermolabil, allicin as the main antioxidant that can prevent free radicals. Nanoemulsion has a particle size of 20-500 nm which is an oil and water dispersion system stabilized by a combination of surfactant and cosurfactant. The purpose of this study was to obtain the best formula from the variation of VCO concentration 3%, 5%, 8% and determine the stability of nanoemulsion preparations. Nanoemulsions are formulated in oil phase VCO, surfactant Tween 80, and cosurfactant PEG 400. Nanoemulsion preparation performed organoleptic test, pH, viscosity , transmittance%, stability. The best Formula continued particle size test, and zeta potential. This study used laboratory experimental method, the results of the study were analyzed by one way ANOVA test. Obtained the best formula of nanoemulsion preparation of garlic bulb extract at a concentration of 8% VCO, the best formula physical results with clear yellow organoleptic characteristics, distinctive odor, and does not separate, pH value 4.9, viscosity value 7.0 d'pas, transmitan % value 96.11, nanoemulsion preparation of garlic bulb stable after stability test. The best Formula in Continue particle size test is the average value obtained 607.0, 53.4 and the average value of the potential Zeta test obtained -5.7, 0.86. The higher the concentration of VCO, the stability of smakin good preparation, nanoemulsion preparation that has good stability in formula 3 with a concentration of 8% VCO.

Optimization of Tween 80 and PEG-400 Concentration in Indonesian Virgin Coconut Oil Nanoemulsion as Antibacterial against Staphylococcus aureus

Virgin Coconut Oil (VCO) can act as an antibacterial due to free fatty acids. To increase the stability of VCO, the VCO can be formed into nanoemulsion preparations. This study aimed to optimize the concentration of Tween 80 and Polyethylene glycol-400 (PEG-400) in nanoemulsion formula and determine antibacterial activity against Staphylococcus aureus. The content of VCO was determined using Gas Chromatography-Mass Spectrometry (GC-MS), and the results showed that VCO contained lauric acid, palmitic acid, caprylic acid, oleic acid, capric acid, and stearic acid. Optimization was carried out using the 22 factorial design method on the response of pH, density, percent transmittance, particle size, and polydispersity index. The optimum formula was obtained at concentrations of Tween 80 and PEG-400 40% and 26%, respectively, with a desirability value of 0.961. The optimum formula showed no phase separation and a significant decrease in pH (p&gt;0.05). The optimum and comparison formula (pure VCO) had significantly different antibacterial activity (p&lt;0.05) where the diameter of the inhibition zone was 24.77±1.66 mm and 16.73±2.00 mm, Minimum Inhibitory Concentration (MIC) of 1250 ppm and 2500 ppm, Minimum Bactericidal Concentration (MBC) of 2500 ppm and more than 2500 ppm, respectively. The optimum formula of VCO nanoemulsion was proven to have good stability and a potent antibacterial activity.

Preparation of lemon essential oil nanoemulsion and its effect on the microbial community of pork patties.

The purpose of this study was to prepare an essential oil nanoemulsion and apply it to meat products to achieve antimicrobial effect. The nanoemulsion of lemon essential oil was produced by high power ultrasonication. The influences of ultrasonic power, ultrasonic time, and mass ratio of sodium caseinate to essential oil on the particle size were examined. The optimal conditions for preparing nanoemulsion were ultrasonic power 327W, ultrasonic time 18min, and sodium caseinate to essential oil mass ratio 4.23:1. Lower temperature was more conducive to the preservation of nanoemulsion. Compared to control and essential oil group, the nanoemulsion could decrease the total volatile basic nitrogen content and total bacterial colony in pork patties. When applied to pork patties, the nanoemulsion decreased the microbial diversity and inhibited the growth of a variety of microorganisms such as Bacillus, extending the storage time of pork patties. This study developed a novel and workable nanoemulsion for inhibiting bacteria of meat products.

Preparation of nano emulsion with high salt resistance

In this paper, the high salt shale reservoir as the research object, through the combination of microemulsion dilution method and pseudo-ternary phase diagram to screen the salt resistance of good nano emulsion. In the system, D-limonene was used as the oil phase, and the surfactant CAB-35 and AOS were selected by pseudo-ternary phase diagram method as the surfactant in the ratio of 1:1, and then mixed with n-butanol in the ratio of 1:1 to obtain the best microemulsion effect. The nano emulsion system was prepared by diluting the microemulsion. By testing the interfacial tension, the optimum preparation conditions of nano emulsion were screened. The results showed that the nano emulsion prepared by dilution under the condition of 5:5 oil/water ratio of microemulsion system had the best ability to reduce the interfacial tension between oil and water.

Transforming monomeric globulins into pickering particles to stabilize nanoemulsions: Contribution of trehalose

Monomeric globulins have been widely employed in food-grade nanoemulsion preparation owing to their outstanding emulsification performance. However, a limitation to stabilize nanoemulsions during storage exists when using monomeric globulin as sole emulsifier, mainly due to the low structural stability of protein during emulsification and at water-oil interface. In the current work, an efficient strategy to fabricate ultra-stable protein-based nanoemulsions was proposed through the incorporation of trehalose to enhance the structural stability of bovine serum albumin (as a model monomeric globulin) in the aqueous phase. The as-prepared nanoemulsions exhibited a high stability against droplet flocculation and coalescence during emulsification and upon long-term storage. Further analyses indicated that the presence of trehalose could form a “shell” structure around protein particles to protect protein against denaturation, unfolding and aggregation during microfluidization. The globulins in trehalose-rich system could behave as a kind of soft nanoparticles with a strong structural integrity and were unaffected by adsorption at the interface. Moreover, the existence of abundant aggregated trehalose greatly favored protein diffusion and adsorption and contributed to more balanced protein wettability, thus allowing monomeric globulins to stabilize more interfaces with Pickering effect. The findings are of value for providing a strategy to prepare stable nanoemulsion using monomeric globulins as the sole emulsifier by simply transforming monomeric globulins into Pickering nanoparticles with the addition of trehalose.

Preparation of pumpkin oil-based nanoemulsion as a potential estrogen replacement therapy to alleviate neural-immune interactions in an experimental postmenopausal model

As estrogen production decreases during menopause; the brain's metabolism tends to stall and become less effective. Estrogen most likely protects against neurodegeneration. Consequently, a comprehensive study of the benefits of hormone replacement therapy as a neuroprotective effect is urgently required. This study was designed to fabricate pumpkin seed oil nanoparticles (PSO) in nanoemulsion form (PSO-NE) and investigate their potential role in attenuating the neural-immune interactions in an experimental postmenopausal model.Sixty female white albino rats were divided into six groups: control, sham, ovariectomized (OVX), and three OVX groups treated with 17β-estradiol, PSO, and PSO-NE respectively. Transmission Electron Microscopy (TEM), and particle size analyzer were performed for nanoemulsion evaluation. Serum levels of estrogen, brain amyloid precursor protein (APP), serum levels of nuclear factor kappa B (NF-κβ), interleukin 6 (IL-6), transthyretin (TTR), and synaptophysin (SYP) were evaluated. The expression of estrogen receptors (ER-α, β) in the brain tissue was estimated. The findings revealed that the approached PSO-NE system was able to reduce the interfacial tension, enhance the dispersion entropy, lower the system free energy to an extremely small value, and augment the interfacial area. PSO-NE, showed a significant increase in the levels of estrogen, brain APP, SYP, and TTR accompanied with a significant increased in the expression of brain ER-α, β compared to the OVX group. In conclusion, the phytoestrogen content of PSO exhibited a significant prophylactic effect on neuro-inflammatory interactions, ameliorating both estrogen levels and the inflammatory cascades.

Hospital Production of Sterile 2% Propofol Nanoemulsion: Proof of Concept.

In the context of essential drug shortages, this article reports a proof of concept for the hospital preparation of a 2% propofol injectable nanoemulsion. Two processes for propofol were assessed: mixing propofol with the commercial Intralipid® 20% emulsion and a "de novo" process performed using separate raw materials (i.e., oil, water, and surfactant) and optimized for droplet size reduction with a high-pressure homogenizer. A propofol HPLC-UV stability-indicating method was developed for process validation and short-term stability. In addition, free propofol in the aqueous phase was quantified by dialysis. To envision routine production, sterility and endotoxin tests were validated. Only the "de novo" process using high-pressure homogenization gave satisfactory physical results similar to commercialized Diprivan® 2%. Both terminal heat sterilization processes (121 °C, 15 min and 0.22 µm filtration) were validated, but an additional pH adjustment was required prior to heat sterilization. The propofol nanoemulsion was monodisperse with a 160 nm mean droplet size, and no droplets were larger than 5µm. We confirmed that free propofol in the aqueous phase of the emulsion was similar to Diprivan 2%, and the chemical stability of propofol was validated. In conclusion, the proof of concept for the in-house 2% propofol nanoemulsion preparation was successfully demonstrated, opening the field for the possible production of the nanoemulsion in hospital pharmacies.

Preparation of starch-based nanoemulsion for sustained release and enhanced bioaccessibility of quercetin

Quercetin is an essential flavonoid with various activities, but it has low bioaccessibility and poor stability. In the present study, an oil-in-water nanoemulsion stabilized by octenyl succinic anhydride modified starch (OSA-CS) was prepared for the delivery, controlled release, enhanced bioaccessibility of quercetin and probing the release mechanism of quercetin from the emulsion in the gastrointestinal tract. OSA-CS with higher substitution than commercially available starch was prepared, and quercetin-loaded nanoemulsions with good storage stability were prepared using it as an emulsifier. The encapsulation efficiency of quercetin in this emulsion was 80.3%, and the loading efficiency was 48.8%, higher than the current study. The release mechanism and bioaccessibility of the starch-based quercetin emulsion during in vitro digestion were explored using in vitro oral, gastric, and intestinal digestion models, and the in vivo delivery ability of the quercetin emulsion was verified in mouse experiments. The release of quercetin from the nanoemulsion in the gastrointestinal tract had the highest fit with the Korsmeyer–Peppas model (R2 > 0.99) and had a high fit with the Higuchi model (R2 = 0.8651), suggesting that diffusion and erosion were the primary release mechanisms. In vivo experiments showed that the nanoemulsions prepared in this study had good quercetin delivery properties. The delivery system substantially improved the bioaccessibility of quercetin from 1.90% to 13.4%, which was superior to other emulsion systems.

Antibacterial Activity of Rosemary Oil Against Propionibacterium acnes and The Formulation into Nanoemulsion System

Acne is an inflammatory condition of the pilosebaceous unit that can occur due to infection ofPropionibacterium acnes. Rosemary essential oil contains various active compounds that haveantibacterial activity. Nanoemulsions have been developed as a delivery system to the pilosebaceousunit. This study aimed to determine the antibacterial activity of rosemary oil against P. acnes anddevelop it into a nanoemulsion system. The antibacterial activity was conducted by the agar diffusionmethod. Rosemary oil contains 1,8-cineole as the main active compound and has antibacterial activityagainst P. acnes with an inhibitory zone of 11.315±0.069 mm at a concentration of 4%. Rosemaryoil was successfully developed into a nanoemulsion system using Tween 80 as a surfactant and acombination of ethanol and PEG 400 as a co-surfactant. The rosemary nanoemulsion has a clearphysical appearance with an average globule size of 33.50±0.01 nm and a PDI value of 0.45±0.03. Thepreparation has good physical stability based on centrifugation, heating cooling, and freeze-thaw tests.The study shows that rosemary oil has antibacterial activity against P. acnes and has been successfullydeveloped into nanoemulsion preparations with good characteristics and physical stability. Keywords: Acne vulgaris, Nanoemulsion, Propionibacterium acnes, Rosemary oil.

Preparation and Evaluation of Nanoemulsion of Citronella Essential Oil with Improved Antimicrobial and Anti-Cancer Properties

The development of new pharmaceutical solutions for treating various diseases results from a growing understanding of the benefits of using essential oils. One of the most often used volatile materials among essential oils is the oil of the citronella plant, termed citronella essential oil (CITEO), which has potential for use in food and medicine. Its wide use is limited due to lipophilicity, high volatility and poor physicochemical stability. With this background, the present study aims to evaluate the properties of CITEO-nanoemulsion (CITEO-NE) by analyzing its antimicrobial activities against Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) and its anticancer activity against, human skin adenocarcinoma cell line (A431). The CITEO-NE was prepared and evaluated for the size range of 130 ± 5 nm, polydispersity index (PDI) of 0.127 and zeta potential -12.6 mV. The percentage % of entrapment efficiency (%EE) of nanoemulsions loaded with CIT was very high at the beginning of the study, at 95.5 ± 4.775%. The MIC was observed to be 500 µg/mL for CITEO and 250 µg/mL for CITEO-NE against S. aureus and 250 µg/mL for CITEO and 125 µg/mL for CITEO-NE against C. albicans. The time-kill assay also suggests the effectiveness of CITEO-NE against the test pathogens as a novel alternative therapy. The IC50 values of CITEO and CITEO-NE exhibited significant cytotoxic properties against the A431 cell line, with 41.20 μg/mL and 37.71 μg/mL, respectively. Hence, our findings revealed that encapsulation of CITEO increased the pharmacological properties.

Gingerol and Shogaol Nanoemulsion of Ginger Extract-based Subcritical Water Extraction

The aim of the present study was determine optimum processing conditions and nanoemulsion formulation for the preparation of gingerol and shogaol nanoemulsion from ginger extract-based subcritical water. For this purpose, nanoemulsions were prepared with rotor-stator homogenizer and varied surfactant and cosurfactant concentrations (24%, 26% and 28% v/v), and stirring speed (22,000 rpm, 24,000 rpm). The stirring time is adjusted to 30 minutes. The density, viscosity, pH, % transmittance, nanoemulsion type test, centrifugation test, particle size, zeta potential, and polydispersion index was observed. Nanoemulsion with 28% emulsifier has a % transmittance value closest to 100% indicating that the particle size is estimated at nanometers. The results of test showed that the formed ginger extract nanoemulsion was unstable. Therefore, further studies are needed to find the optimum process conditions and nanoemulsion formulations to form stable

Quantification of Xanthone and Anthocyanin in Mangosteen Peel by UPLC-MS/MS and Preparation of Nanoemulsions for Studying Their Inhibition Effects on Liver Cancer Cells

Mangosteen peel, a waste produced during mangosteen processing, has been reported to be rich in xanthone and anthocyanin, both of which possess vital biological activities such as anti-cancer properties. The objectives of this study were to analyze various xanthones and anthocyanins in mangosteen peel by UPLC-MS/MS for the subsequent preparation of both xanthone and anthocyanin nanoemulsions to study their inhibition effects on liver cancer cells HepG2. Results showed that methanol was the optimal solvent for the extraction of xanthones and anthocyanins, with a total amount of 68,543.39 and 2909.57 μg/g, respectively. A total of seven xanthones, including garcinone C (513.06 μg/g), garcinone D (469.82 μg/g), γ-mangostin (11,100.72 μg/g), 8-desoxygartanin (1490.61 μg/g), gartanin (2398.96 μg/g), α-mangostin (51,062.21 μg/g) and β-mangostin (1508.01 μg/g), as well as two anthocyanins including cyanidin-3-sophoroside (2889.95 μg/g) and cyanidin-3-glucoside (19.72 μg/g), were present in mangosteen peel. The xanthone nanoemulsion was prepared by mixing an appropriate portion of soybean oil, CITREM, Tween 80 and deionized water, while the anthocyanin nanoemulsion composed of soybean oil, ethanol, PEG400, lecithin, Tween 80, glycerol and deionized water was prepared as well. The mean particle size of the xanthone extract and nanoemulsion were, respectively, 22.1 and 14.0 nm as determined by DLS, while the zeta potential was -87.7 and -61.5 mV. Comparatively, xanthone nanoemulsion was more effective than xanthone extract in inhibiting the growth of HepG2 cells, with the IC50 being 5.78 μg/mL for the former and 6.23 μg/mL for the latter. However, the anthocyanin nanoemulsion failed to inhibit growth of HepG2 cells. Cell cycle analysis revealed that the proportion of the sub-G1 phase followed a dose-dependent increase, while that of the G0/G1 phase showed a dose-dependent decline for both xanthone extracts and nanoemulsions, with the cell cycle being possibly arrested at the S phase. The proportion of late apoptosis cells also followed a dose-dependent rise for both xanthone extracts and nanoemulsions, with the latter resulting in a much higher proportion at the same dose. Similarly, the activities of caspase-3, caspase-8 and caspase-9 followed a dose-dependent increase for both xanthone extracts and nanoemulsions, with the latter exhibiting a higher activity at the same dose. Collectively, xanthone nanoemulsion was more effective than xanthone extract in inhibiting the growth of HepG2 cells. Further research is needed to study the anti-tumor effect in vivo.

Preparation of tea tree oil nanoemulsion: Characterisation, antibacterial mechanism and evaluation of apoptosis

AbstractTea tree oil (TTO) is a natural plant essential oil that has strong bactericidal properties and low toxicity. However, owing to its irritability, volatility, instability under light/oxygen and hydrophobicity, the application of TTO in pharmaceutical production technology and the food industry is limited. To overcome these problems, TTO nanoemulsions (TTONs) were prepared using a high‐speed shearing method. The mean droplets size of TTON was measured. TTON droplets were observed using confocal laser scanning microscopy and analysed using a Turbiscan scanning spectrum. The most suitable nanoemulsion formula was obtained as follows: TTO content, 10% (w/w); Tw‐40 content, 8% (w/w); deionised water content, 82% (w/w); shearing time, 5 minutes. The antibacterial effect of TTON was studied, and it was found that its antibacterial activity against Escherichia coli was more potent than that against Staphylococcus aureus. The antibacterial mechanism of TTON was also investigated by observing bacterial morphology using scanning electron microscopy and testing the levels of bacterial reactive oxygen species. The effect of TTON on L‐02 cells was evaluated. The results showed that the cell survival rates of L‐02 cells treated with TTON at 0.05‐0.25 μg/μL were all &gt;90%. At each concentration, the total apoptosis rate of L‐02 cells was &lt;10%. These results indicated the high biocompatibility and biological safety of TTON. Therefore, the preparation of TTO into a nanoemulsion can improve its bioavailability, which has positive implications for further applications of TTO.