Preparation, process optimisation, stability and bacteriostatic assessment of composite nanoemulsion containing corosolic acid

Corosolic acid (CA), a pentacyclic triterpenoid, exhibits remarkably low hydrophilicity, restricting its application in aqueous systems. To enhance its hydrophilicity, we optimised nanoemulsion preparation conditions, resulting in a stable corosolic acid nanoemulsion system. By screening the oil phase, surfactant, and cosurfactant, along with investigating the mass ratio of surfactant and cosurfactant and the preparation temperature, we achieved an optimal corosolic acid nanoemulsion. We measured the particle size, polydispersity coefficient, and Zeta potential of the optimised formulation. The nanoemulsion's sustained-release effect, stability, and antibacterial activity were subsequently examined. The optimised formulation comprised ethyl oleate, cremophor EL, and Tween 80 (1.5:1), combined with ethanol in a ratio of 1:9:2.25 (w/w/w), and was prepared at 30 °C. This optimised corosolic acid nanoemulsion exhibited uniform particle size distribution, favourable dispersion, and notable slow-release capabilities. Importantly, the nanoemulsion demonstrated exceptional stability. In comparison to the positive control's bacteriostatic zone diameter, it was evident that the CA nanoemulsion (1.06 ± 0.11 mm) and blank nanoemulsion (1.03 ± 0.05 mm) both displayed notable inhibitory activity against S. aureus. Our findings established a solid foundation for the potential application of CA nanoemulsion in the food, cosmetics, and pharmaceutical industries. However, the application of CA nanoemulsion in real food or drug systems has not been explored yet.

Anticancer activity of Curcuma aeroginosa essential oil and its nano-formulations: cytotoxicity, apoptosis and cell migration effects

BACKGROUND AND AIMS

Curcuma aeruginosa, commonly known as "kha-min-dam" in Thai, holds significance in Asian traditional medicine due to its potential in treating various diseases, having properties such as anti-HIV, hepatoprotective, antimicrobial and anti-androgenic activities. This study explores the anticancer activity of C. aeruginosa essential oil (CAEO) and its nano-formulations.

METHODS

CAEO obtained from hydrodistillation of C. aeruginosa fresh rhizomes was examined by gas chromatography mass spectroscopy. Cytotoxicity of CAEO was determined in leukaemic K562 and breast cancer MCF-7 cell lines using an MTT assay. Cell cycle analysis and cell apoptosis were determined by flow cytometry. Cell migration was studied through a wound-healing assay.

RESULTS

Benzofuran (33.20%) emerged as the major compound of CAEO, followed by Germacrene B (19.12%) and Germacrone (13.60%). Two types of CAEO loaded nano-formulations, nanoemulsion (NE) and microemulsion (ME) were developed. The average droplet sizes of NE and ME were 13.8 ± 0.2 and 21.2 ± 0.2 nm, respectively. In a comparison with other essential oils from the fresh rhizomes of potential plants from the same family (Curcuma longa, Curcuma mangga and Zingiber officinale) on anticancer activity against K562 and MCF-7 cell lines, CAEO exhibited the highest cytotoxicity with IC50 of 13.43 ± 1.09 and 20.18 ± 1.20 µg/mL, respectively. Flow cytometry analysis revealed that CAEO significantly increased cell death, evidenced from the sub-G1 populations in the cell cycle assay and triggered apoptosis. Additionally, CAEO effectively inhibited cell migration in MCF-7 cells after incubation for 12 and 24 h. The developed NE and ME formulations significantly enhanced the cytotoxicity of CAEO against K562 cells with an IC50 of 45.30 ± 1.49 and 41.98 ± 0.96 µg/mL, respectively.

CONCLUSION

This study's finding suggest that both nano-formulations, NE and ME, effectively facilitated the delivery of CAEO into cancer cells.

Natural food preservation with ginger essential oil: Biological properties and delivery systems

Recently, the increasing demand from consumers for preservative-free or naturally preserved foods has forced the food industry to turn to natural herbal and plant-derived preservatives rather than synthetic preservatives to produce safe foods. Essential oils derived from ginger (Zingiber officinale Roscoe) are widely known for their putative health-promoting bioactivities, and this paper covers their extraction methods, chemical composition, and antibacterial and antioxidant activities. Especially, the paper reviews their potential applications in food preservation, including nanoemulsions, emulsions, solid particle encapsulation, and biodegradable food packaging films/coatings. The conclusion drawn is that ginger essential oil can be used not only for direct food preservation but also encapsulated using various delivery forms such as nanoemulsions, Pickering emulsions, and solid particle encapsulation to improve its release control ability. The film of encapsulated ginger essential oil has been proven to be superior to traditional methods in preserving foods such as bread, meat, fish, and fruit.

Encapsulation of Ginger Extract in Nanoemulsions: Preparation, Characterization and in vivo Evaluation in Rheumatoid Arthritis

Ginger is an anti-inflammatory and antioxidant natural substance, however, its effectiveness is limited primarily due to insufficient solubility and low oral bioavailability. This study aimed to formulate ginger extract into nanoemulsion (NE) to enhance therapeutic benefits against rheumatoid arthritis (RA). Hence, ginger extract-loaded NEs were prepared by the spontaneous emulsification method. The NE that passed the thermodynamic stability analyses showed no phase changes or appearance of turbidity. They had an average droplet diameter of 76 ± 45 nm with a zeta potential of - 35 ± 12 mV. Besides, the high antioxidant activities (IC50 = 53.89 µg/mL), about ten times increment of the skin permeability, and no sign of skin irritancy were observed from the ginger-loaded NE. The anti-arthritic evaluations of RA-induced rats treated with ginger-loaded NE showed a significant decline in arthritic symptoms and the highest rate of paw edema inhibition (27.7 %). In addition, the level of involved inflammatory cytokines in the serum of rats was significantly reduced (p < 0.05) compared to the negative control, so that histopathological manifestations also approved the reduction of inflammation indications. Thus, the topical delivery of ginger-loaded NE can be an efficient approach for reducing inflammation and inhibit of RA symptoms.

Ginger Loaded Polyethylene Oxide Electrospun Nanomembrane: Rheological and Antimicrobial Attributes

Synthetic antibiotics have captured the market in recent years, but the side effects of these products are life-threatening. In recent times, researchers have focused their research on natural-based products such as natural herbal oils, which are eco-friendly, biocompatible, biodegradable, and antibacterial. In this study, polyethylene oxide (PEO) and aqueous ginger extract (GE) were electrospun to produce novel antibacterial nanomembrane sheets as a function of PEO and GE concentrations. A GE average particle size of 91.16 nm was achieved with an extensive filtration process, inferring their incorporation in the PEO nanofibres. The presence of the GE was confirmed by Fourier transform infrared spectroscopy (FTIR) through peaks of phenol and aromatic groups. The viscoelastic properties of PEO/GE solutions were analysed in terms of PEO and GE concentrations. Increasing PEO and GE concentrations increased the solution's viscosity. The dynamic viscosity of 3% was not changed with increasing shear rate, indicating Newtonian fluid behaviour. The dynamic viscosity of 4 and 5 wt% PEO/GE solutions containing 10% GE increased exponentially compared to 3 wt%. In addition, the shear thinning behaviour was observed over a frequency range of 0.05 to 100 rad/s. Scanning Electron Microscopy (SEM) analysis also specified an increase in the nanofibre's diameter with increasing PEO concentration, while SEM images displayed smooth morphology with beadless nanofibres at different PEO/GE concentrations. In addition, PEO/GE nanomembranes inhibited the growth of Staphylococcus aureus, as presented by qualitative antibacterial results. The extent of PEO/GE nanomembrane's antibacterial activity was further investigated by the agar dilution method, which inhibited the 98.79% Staphylococcus aureus population at 30% GE concentration.

Synthesis and Characterization of Silver Nanoparticles from Rhizophora apiculata and Studies on Their Wound Healing, Antioxidant, Anti-Inflammatory, and Cytotoxic Activity

Silver nanoparticles (AgNPs) have recently gained interest in the medical field because of their biological features. The present study aimed at screening Rhizophora apiculata secondary metabolites, quantifying their flavonoids and total phenolics content, green synthesis and characterization of R. apiculata silver nanoparticles. In addition, an assessment of in vitro cytotoxic, antioxidant, anti-inflammatory and wound healing activity of R. apiculata and its synthesized AgNPs was carried out. The powdered plant material (leaves) was subjected to Soxhlet extraction to obtain R. apiculata aqueous extract. The R. apiculata extract was used as a reducing agent in synthesizing AgNPs from silver nitrate. The synthesized AgNPs were characterized by UV-Vis, SEM-EDX, XRD, FTIR, particle size analyzer and zeta potential. Further aqueous leaf extract of R. apiculata and AgNPs was subjected for in vitro antioxidant, anti-inflammatory, wound healing and cytotoxic activity against A375 (Skin cancer), A549 (Lung cancer), and KB-3-1 (Oral cancer) cell lines. All experiments were repeated three times (n = 3), and the results were given as the mean ± SEM. The flavonoids and total phenolics content in R. apiculata extract were 44.18 ± 0.086 mg/g of quercetin and 53.24 ± 0.028 mg/g of gallic acid, respectively. SEM analysis revealed R. apiculata AgNPs with diameters ranging from 35 to 100 nm. XRD confirmed that the synthesized silver nanoparticles were crystalline in nature. The cytotoxicity cell viability assay revealed that the AgNPs were less toxic (IC₅₀ 105.5 µg/mL) compared to the R. apiculata extract (IC₅₀ 47.47 µg/mL) against the non-cancerous fibroblast L929 cell line. Antioxidant, anti-inflammatory, and cytotoxicity tests revealed that AgNPs had significantly more activity than the plant extract. The AgNPs inhibited protein denaturation by a mean percentage of 71.65%, which was equivalent to the standard anti-inflammatory medication diclofenac (94.24%). The AgNPs showed considerable cytotoxic effect, and the percentage of cell viability against skin cancer, lung cancer, and oral cancer cell lines was 31.84%, 56.09% and 22.59%, respectively. R. apiculata AgNPs demonstrated stronger cell migration and percentage of wound closure (82.79%) compared to the plant extract (75.23%). The overall results revealed that R. apiculata AgNPs exhibited potential antioxidant, anti-inflammatory, wound healing, and cytotoxic properties. In future, R. apiculata should be further explored to unmask its therapeutic potential and the mechanistic pathways of AgNPs should be studied in detail in in vivo animal models.

Novel Curcumin-Encapsulated α-Tocopherol Nanoemulsion System and Its Potential Application for Wound Healing in Diabetic Animals

Objective

This project was aimed at formulating a novel nanoemulsion system and evaluating it for open incision wound healing in diabetic animals.

Methods

The nanoemulsions were characterized for droplet size and surface charge, drug content, antioxidant and antimicrobial profiling, and wound healing potential in diabetic animals. The skin samples excised were also analyzed for histology, mechanical strength, and vibrational and thermal analysis.

Results

The optimized nanoemulsion (CR-NE-II) exhibited droplet size of26.76 ± 0.9 nm with negative surface charge (−10.86 ± 1.06 mV), was homogenously dispersed with drug content of68.05 ± 1.2%, released almost82.95 ± 2.2%of the drug within first 2 h of experiment with synergistic antioxidant (95 ± 2.1%) and synergistic antimicrobial activity against selected bacterial strains in comparison to blank nanoemulsion, and promoted significantly fast percent reepithelization (96.47%). The histological, vibrational, thermal, and strength analysis of selected skin samples depicted a uniform and even distribution of collagen fibers which translated into significant increase in strength of skin samples in comparison to the control group.

Conclusions

The optimized nanoemulsion system significantly downregulated the oxidative stress, enhanced collagen deposition, and precluded bacterial contamination of wound, thus accelerating the skin tissue regeneration process.

Prevention of Aflatoxin Occurrence Using Nuts-Edible Coating of Ginger Oil Nanoemulsions and Investigate the Molecular Docking Strategy

The modern utilization of essential oils such as ginger oil (GO) as an anti-aflatoxin represents a potential target for food preservation and safety; however, the mechanism of action is still unclear. Nanoemulsions, through an edible coating, can enhance the oil’s bioactivity, increase its hydrophilicity, and extend the final product’s shelf-life. In the present study, two edible films for the GO nanoemulsion were prepared by ultrasonication using carboxymethyl cellulose (FB1-GO) and sodium alginate (FB2-GO). The droplet size of FB2-GO was finer (126.54 nm) compared to FB1-GO (289.77 nm). Meanwhile, both had high stability proved by z-potential; +31.54 mV (FB1-GO) and +46.25 mV (FB2-GO) with low PDI values (<0.4). Using gas chromatography-mass spectrometry, the hydrodistilled GO showed 25 compounds, representing 99.17% of the total oil, with α-zingiberene (29.8%), geranial (10.87%), β-bisabolene (8.19%), and ar-curcumene (5.96%) as the predominant. A dramatic increase in α-zingiberene, α-bisabolene and ar-curcumene was due to the homogenization conditions in both FB1-GO and FB2-GO compared to the GO. The FB1-GO exhibited superior antibacterial activity against the examined strains of bacterial pathogens, while FB2-GO was more effective as an antifungal agent on the tested Aspergillus fungi strains. In a simulated liquid media, FB2-GO inhibited the total growth of fungi by 84.87−92.51% and showed the highest reduction in the aflatoxin amount produced. The in silico study presented that, among the GO volatile constituents, sesquiterpenes had the highest binding free energies against the enzymes responsible for aflatoxin production compared to monoterpenes. α-Bisabolene showed the highest affinity toward polyketide synthase (−7.5 Kcal/mol), while ar-curcumene was the most potent against cytochrome P450 monooxygenase (−8.3 Kcal/mol). The above findings clarify the reasons for aflatoxin reduction in simulated media during incubation with FB1-GO and FB2-GO.

Developing three-component ginger-cinnamon-cardamom composite essential oil nanoemulsion as natural food preservatives

Plant-based functional lipid ingredients, such as essential oils, with antioxidant and antibacterial activities, have gained substantial attention in food, cosmetic, and pharmaceutical formulations due to the increasing disquiet about the risks of artificial preservatives. However, similar to other lipid-based bioactives, their application in water-based products is challenging owing to their low water solubility and high chemical instability, especially during exposure to light, heat, moisture, and oxygen. Hence, the incorporation of essential oils into water-dispersible nanoemulsion systems can effectively address these issues. Moreover, combining various essential oils can synergistically enhance their chemical and biological properties. Consequently, the objective of this study was to develop different composite nanoemulsion systems using ginger, cinnamon, and cardamom essential oils, which were considered individually and in binary and ternary combinations. Empirical models to predict the response characteristics based on the proportions of oil phase components were also derived. The numerical multi-goal optimisation analysis suggested that 10 % ginger, 68 % cinnamon, and 22 % cardamom essential oil is the ideal oil phase combination to achieve nanoemulsions with the smallest average particle size and size distribution and the highest zeta potential and antioxidant and antibacterial activity.

Anticancer activity of Zingiber ottensii essential oil and its nanoformulations

Zingiber ottensii, is widely used in Asian traditional remedies for the treatment of many diseases. The present study explores anticancer activity of Z. ottensii essential oil (ZOEO) and its nanoformulations. ZOEO obtained from hydrodistillation of Z. ottensii fresh rhizomes was analysis using gas chromatography mass spectroscopy. Zerumbone (25.21%) was the major compound of ZOEO followed by sabinene (23.35%) and terpene-4-ol (15.97%). Four types of ZOEO loaded nanoformulations; nanoemulsion, microemulsion, nanoemulgels, and microemulgel, were developed. The average droplet size of the nanoemulsion and microemulsion was significantly smaller than that of the nanoemulgel and microemulgel. Comparison with other essential oils of plants of the same family on anticancer activity against A549, MCF-7, HeLa, and K562, ZOEO showed the highest cytotoxicity with IC50 of 43.37±6.69, 9.77±1.61, 23.25±7.73, and 60.49±9.41 μg/mL, respectively. Investigation using flow cytometry showed that ZOEO significantly increased the sub-G1 populations (cell death) in cell cycle analysis and induced cell apoptosis by apoptotic analysis. The developed nanoformulations significantly enhanced cytotoxicity of ZOEO, particularly against MCF-7 with the IC50 of 3.08±2.58, 0.74±0.45, 2.31±0.91, and 6.45±5.84 μg/mL, respectively. Among the four nanoformulations developed in the present study, nanoemulsion and microemulsion were superior to nanoemulgel and microemulgel in delivering ZOEO into cancer cells.