Antioxidative, anticancer, and antibacterial activities of a nanoemulsion-based gel containing Myrtus communis L. essential oil

Anticancer Potential of Cymbopogon citratus L. Essential Oil: In Vitro and In Silico Insights into Mitochondrial Dysfunction and Cytotoxicity in Cancer Cells

This study aims to assess the potential anticancer activity of lemongrass essential oil (LEO) using in vitro and in silico methods. The steam hydrodistillation of the aerial parts yielded 3.2% (wt) LEO. The GC-MS analysis of the LEO revealed the presence of α-citral (37.44%), β-citral (36.06%), linalool acetate (9.82%), and d-limonene (7.05%) as major components, accompanied by several other minor compounds. The antioxidant activity, assessed using the DPPH assay, revealed that LEO exhibits an IC50 value of 92.30 μg/mL. The cytotoxic effect of LEO, as well as LEO solubilized with Tween-20 (LEO-Tw) and PEG-400 (LEO-PEG), against a series of cancer cell lines (A375, RPMI-7951, MCF-7, and HT-29) was assessed using the Alamar Blue assay; the results revealed a high cytotoxic effect against all cell lines used in this study. Moreover, neither one of the tested concentrations of LEO, LEO-PG, or LEO-TW significantly affected the viability of healthy HaCaT cells, thus showing promising selectivity characteristics. Furthermore, LEO, LEO-PG, and LEO-TW increased ROS production and decreased the mitochondrial membrane potential (MMP) in all cancer cell lines. Moreover, LEO treatment decreased all mitochondrial respiratory rates, thus suggesting its ability to induce impairment of mitochondrial function. Molecular docking studies revealed that LEO anticancer activity, among other mechanisms, could be attributed to PDK1 and PI3Kα, where the major contributors are among the minor components of the essential oil. The highest active theoretical inhibitor against both proteins was β-caryophyllene oxide.

Tiryāq in traditional Persian medicine: a survey of antidotal plants and their modern pharmacological potential

Purpose

Tiryāq (Theriac) refers to a single or compound medication historically utilized as a general antidote against numerous poisons in several ethnomedical traditions, especially in traditional Persian medicine (PM). This study aims to summarize the traditional uses, phytochemistry, and pharmacological activities of medicinal plants with tiryāq properties, with a particular focus on their anti-hepatotoxic, hepatoprotective, neuroprotective, and cardioprotective activities.

Methods

Classical texts of traditional PM were broadly reviewed to extract information about tiryāq and its mechanisms. In addition, a detailed search of scientific databases was performed to validate the pharmacological properties of plants traditionally recognized for their antidotal effects.

Results

Thirty-one medicinal plants with antidote properties were identified. The primary function of tiryāq, as described in PM, is to neutralize toxins and bolster the immune system. These plants have cardiotonic, hepatoprotective, and neuroprotective properties. In addition to their antidotal applications, tiryāq remedies were traditionally used to manage chronic cough, stomachache, asthma, colic, and other ailments. Modern pharmacological studies support these applications, highlighting the plants' antiviral, immunomodulatory, and antioxidant properties, especially against acute respiratory viral infections and other inflammatory circumstances.

Conclusion

Tiryāq plays a pivotal role in fortifying essential organs, including the heart, brain, and liver. Its prophylactic use during epidemics, along with its antioxidant and immune-stimulating properties, underscores its therapeutic potential. Further research is needed to conclusively determine the efficacy and broader therapeutic applications of medicinal plants with tiryāq properties.

Larvicidal Efficacies of Nanoliposomes Containing Alpha-pinene, Citral, Camphor, and Thymol Against Aedes aegypti and Anopheles stephensi Mosquito Vectors

BACKGROUND

Diseases transmitted by Aedes aegypti or Anopheles stephensi, such as Zika virus, dengue fever, and malaria, pose substantial risks to public health, particularly in tropical areas. Plant-derived compounds have emerged as promising alternatives due to their inherent safety and potential efficiency against mosquitoes. This study aimed to improve the efficacy of certain natural compounds, including α-pinene, citral, camphor, and thymol, by developing nanoliposomal formulations.

METHODS

The ‎nanoliposomes containing α-pinene, citral, camphor, and thymol were prepared using the ethanol injection method and then characterized. Using WHO-recommended guidelines, their larvicidal efficacy was investigated against Aedes aegypti and Anopheles stephensi.

RESULTS

The ‎nanoliposomes particle sizes were 105 ± 7, 86 ± 5, 149 ± 5, and 135 ± 8 nm, and zeta potentials ‎were - 25.1 ± 0.5, -17.2 ± 1.2, -16.4 ± 1.6, and - 21.3 ± 1.7 mV, respectively. In addition, the ATR-FTIR (Attenuated Total Reflectance-Fourier Transform InfraRed) analysis verified the successful loading of the compound. Nanoliposomal compounds exhibited superior performance compared to their non-formulated counterparts in larvicidal bioassays. The nanoliposomes containing thymol showed the highest efficacy, with a Lethal Concentration 50 (LC50) of 20 µg/mL against Ae. aegypti. Nanoliposomes containing citral exhibited an LC50 of 20 µg/mL against An. stephensi.

CONCLUSIONS

The results suggest that nanoliposomes have the potential to serve as an effective vehicle to improve the efficiency of plant-based larvicides. This could play a significant role in developing sustainable mosquito control strategies.

Investigating the protective effect of Rosa damascena nanogel on collagenase and elastase activity and UVB-induced dermal damage: A rodent model approach to skin photoaging

While aging inevitably changes our skin, this complex biological process involves much more than just getting older. As the body's largest organ, the skin constantly safeguards us from harmful environmental pathogens and plays a key role in overall well-being. This study investigated the development and evaluation of a nanogel containing Rosa damascena essential oil for its potential anti-aging properties. The nanogel was prepared from a primary nanoemulsion with a particle size of 86 ± 4 nm. Antioxidant activity, measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, was found to be 76% ± 3%. Furthermore, the nanogel demonstrated superior anti-collagenase and anti-elastase activities (60% ± 2% and 51% ± 0.1%, respectively) compared to the essential oil alone. The antibacterial efficacy of the nanogel was tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, revealing potent inhibitory effects. To simulate the aging process, rats were subjected to UVB irradiation on both legs 4 days a week before or after treatment. In vivo studies conducted on mice showed that the nanogel effectively reduced the formation of deep wrinkles in treated groups compared to pretreated ones. These findings suggest that the introduced nanogel, with its antioxidant and antimicrobial properties, holds promise as a natural therapeutic approach for wrinkle treatment.

Comparison of the efficacy of alginate nanoparticles containing Cymbopogon citratus essential oil and citral on melanoma and breast cancer cell lines under normoxic and hypoxic conditions

BACKGROUND

Solid tumors often develop hypoxic regions, leading to aggressive behavior and increased drug resistance.

METHODS

The chemical composition of Cymbopogon citratus essential oil (EO) was analyzed using GC-MS. Alginate nanoparticles containing the EO and its primary component, citral, were synthesized via the ionic gelation method. Encapsulation was confirmed using ATR-FTIR analysis. The anticancer efficacy of C. citratus EO, citral, and their respective alginate nanoparticles was evaluated under normoxic (21% oxygen) and hypoxic (1% oxygen) conditions on breast cancer (MDA-MB-231) and melanoma (A-375) cell lines. Additionally, qPCR and flow cytometry were used to assess apoptosis gene expression ratios (Bax/Bcl-2) and levels of apoptosis.

RESULTS

Citral (80.98%) was identified as the major component of the EO. Alginate nanoparticles containing C. citratus EO and citral (C. citratus-AlgNPs and citral-AlgNPs) were synthesized with particle sizes of 195 ± 4 nm and 222 ± 9 nm, and zeta potentials of -22 ± 3 mV and - 17 ± 1 mV, respectively. Both samples demonstrated significantly greater efficacy under hypoxic conditions. Citral and C. citratus-AlgNPs had IC50 values of 27 (19-39) µg/mL and 25 (4-147) µg/mL, respectively, against MDA-MB-231 and A-375 cells. Flow cytometry showed increased apoptosis under hypoxic conditions, with the highest rates observed for citral-AlgNPs and C. citratus-AlgNPs (84 ± 5 and 92 ± 5% in MDA-MB-231 and A-375 cells, respectively).

CONCLUSION

This study demonstrates that alginate nanoparticles enhance the anticancer activity of C. citratus-AlgNPs and citral, particularly under hypoxic conditions, highlighting their potential for hypoxia-targeted cancer therapies.

Nanoformulated herbal compounds: enhanced antibacterial efficacy of camphor and thymol-loaded nanogels

Herbal components are highly useful assets for the advancement of novel antibacterial drugs. Nanotechnology holds great promise as an approach to enhance the effectiveness and develop the composition of these substances. The study developed nanogels incorporating camphor, thymol, and a combination derived from the initial nanoemulsions with particle sizes of 103, 85, and 135 nm, respectively. The viscosity of nanogels and the successful loading of compounds in them were examined by viscometery and ATR-FTIR studies. The bactericidal properties of the nanogels were examined against four bacterial strains. The nanogel containing camphor and thymol at 1250 µg/mL concentration exhibited complete growth suppression against Pseudomonas aeruginosa and Staphylococcus aureus. The thymol nanogel at 1250 µg/mL and the camphor nanogel at 2500 µg/mL exhibited complete inhibition of growth on Listeria monocytogenes and Escherichia coli, respectively. Both nanogels showed favorable effectiveness as antibacterial agents and could potentially examine a wide range of pathogens and in vivo studies.

Current challenges ahead in preparation, characterization, and pharmaceutical applications of nanoemulsions

Nanoemulsions (NEs) are emulsions with particle size of less than around 100 nm. Reviewing the literature, several reports are available on NEs, including preparation, characterization, and applications of them. This review aims to brief challenges that researchers or formulators may encounter when working with NEs. For instance, when selecting NE components and identifying their concentrations, stability and safety of the preparation should be evaluated. When preparing an NE, issues over scale-up of the preparation as well as possible effects of the preparation process on the active ingredient need to be considered. When characterizing the NEs, the two major concerns are accuracy of the method and accessibility of the characterizing instrument. Also a highly efficient NE for clinical use to deliver the active ingredient to the target tissue with maximum safety profile is commonly sought. Throughout the review we also have tried to suggest approaches to overcome the challenges. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

The Leaf Essential Oil of Myrtus communis subsp. tarentina (L.) Nyman: From Phytochemical Characterization to Cytotoxic and Antimigratory Activity in Human Prostate Cancer Cells

The aim of this study was to investigate the chemical profile and the cytotoxic activity in two castration-resistant prostate cancer (CRPC) cell lines of the leaf essential oil in Myrtus communis subsp. tarentina (L.) Nyman (EO MT), which was cultivated at the Ghirardi Botanical Garden (Toscolano Maderno, Brescia, Italy). The leaves were air-dried and extracted by hydrodistillation with a Clevenger-type apparatus, and the EO profile was characterized by GC/MS. For the cytotoxic activity investigation, we analyzed the cell viability by MTT assay, and the apoptosis induction by Annexin V/propidium iodide assay/Western blot analysis of cleaved caspase 3 and cleaved PARP proteins. Moreover, the cellular migration was analyzed by Boyden's chamber assay and the distribution of actin cytoskeleton filaments by immunofluorescence. We identified 29 total compounds; the main compound classes were oxygenated monoterpenes, monoterpene hydrocarbons, and sesquiterpenes. The main constituents were α-pinene, α-humulene, α-terpineol, durohydroquinon, linalool, geranyl acetate, and β-caryophyllene. We found that EO MT was able to reduce cellular viability, activating an apoptotic process, and to decrease the migratory capacity of CRPC cells. These results suggest that it might be interesting to further investigate the effects of single compounds present in EO MT for their possible use in prostate cancer treatment.

Family Myrtaceae: The treasure hidden in the complex/diverse composition

Myrtaceae is one of the most important plants families, being regarded as the eighth largest flowering plant family. It includes many genera of utmost ecological and economical importance distributed all over the world. This review aimed to report the latest studies on this family focusing on certain widely used plants including Eucalyptus sp., Eugenia sp. (Eugenia uniflora, Eugenia sulcata), Syzygium sp. (Syzygium aromaticum and Syzygium cumini), Psidium sp., Pimenta dioica, Myrtus sp. (Myrtus communis), Myrciaria sp. and Melaleuca alternifolia. The extraction of bioactive compounds has been evolving through the optimization of conventional methods and the use of emerging technologies. Supercritical CO2 was applied for essential oils and ultrasound for polyphenols leading to extracts and essential oils rich in bioactive compounds. Advances in the field of encapsulation and delivery systems showed promising results in the production of stable essential oils nanoemulsions and liposomes and the production of plant extracts in the form of nanoparticles. Moreover, a significant increase in the number of patents was noticed especially the application of Myrtaceae extracts in the pharrmacuetucal field. The applications of ceratin plants (Pimenta dioica, Melaleuca alternifolia, Syzygium aromaticum essential oils or Myrciaria cauliflora peel extract) in food area (either as a free or encapsulated form) also showed interesting results in limiting microbial spoilage of fresh meat and fish, slowing oxidative degradation in meat products, and inhibiting aflatoxin production in maize. Despite the massive literature on Myrtaceae plants, advances are still necessary to optimize the extraction with environmentally friendly technologies and carry out risk assessment studies should be accomplished to harness the full potential in food, industrial and pharmaceutical applications.

Nanoemulsion and Nanogel Containing Cuminum cyminum L Essential Oil: Antioxidant, Anticancer, Antibacterial, and Antilarval Properties

Cuminum cyminum L. is a widespread medicinal plant with a broad spectrum of biological activity. In the present study, the chemical structure of its essential oil was examined utilizing GC-MS analysis (gas chromatography-mass spectrometry). Then, a nanoemulsion dosage form was prepared with a droplet size and droplet size distribution (SPAN) of 121 ± 3 nm and 0.96. After that, the dosage form of the nanogel was prepared; the nanoemulsion was gelified by the addition of 3.0% carboxymethyl cellulose. In addition, the successful loading of the essential oil into the nanoemulsion and nanogel was approved by ATR-FTIR (attenuated total reflection Fourier transform infrared) analysis. The IC50 values (half maximum inhibitory concentration) of the nanoemulsion and nanogel against A-375 human melanoma cells were 369.6 (497-335) and 127.2 (77-210) μg/mL. In addition, they indicated some degrees of an antioxidant activity. Interestingly, after treatment of Pseudomonas aeruginosa with 5000 µg/mL nanogel, bacterial growth was completely (∼100%) inhibited. In addition, the growth of Staphylococcus aureus after treatment with the 5000 μg/ml nanoemulsion was decreased by 80%. In addition, nanoemulsion and nanogel LC50 values for Anopheles stephensi larvae were attained as 43.91 (31-62) and 123.9 (111-137) µg/mL. Given the natural ingredients and promising efficacy, these nanodrugs can be regarded for further research against other pathogens or mosquito larvae.

Assessment of Growth Inhibition of Eugenol-Loaded Nano-Emulsions against Beneficial Bifidobacterium sp. along with Resistant Escherichia coli Using Flow Cytometry

The intestinal tract microbiota influences many aspects of the dietary components on colon health and during enteric infections, thus, playing a pivotal role in the colon health. Therefore, the eugenol (EU) nano-emulsion effective concentration reported in our previous study against cancer cells should be explored for safety against beneficial microbes. We evaluated the sensitivity of Bifidobacterium breve and B. adolescentis against EU-loaded nano-emulsions at 0, 300, 600 and 900 µm, which were effective against colon and liver cancer cells. Both B. breve and B. adolescentis showed comparable growth ranges to the control group at 300 and 600 µm, as evident from the plate count experimental results. However, at 900 µm, a slight growth variation was revealed with respect to the control group. The real-time inhibition determination through flow cytometry showed B. breve viable, sublethal cells (99.49 and 0.51%) and B. adolescentis (95.59 and 0.15%) at 900 µm, suggesting slight inhibition even at the highest tested concentration. Flow cytometry proved to be a suitable quantitative approach that has revealed separate live, dead, and susceptible cells upon treatment with EU nano-emulsion against Escherichia coli. Similarly, in the case of B. breve and B. adolescentis, the cells showed only live cells that qualitatively suggest EU nano-emulsion safety. To judge the viability of these sublethal populations of B. breve and B. adolescentis, Fourier transforms infrared spectroscopy was carried out, revealing no peak shift for proteins, lipids, DNA and carbohydrates at 900 µm EU nano-emulsion compared to the control. On the other hand, EU-loaded nano-emulsions (900 µm)-treated E. coli showed a clear peak shift for a membrane protein, lipids, DNA and carbohydrates. This study provides insights to utilize plant phenols as safe medicines as well as dietary supplements.

Nano-scaled emulsion and nanogel containing Mentha pulegium essential oil: cytotoxicity on human melanoma cells and effects on apoptosis regulator genes

BACKGROUND

Topical drug delivery using nanoemulsions and nanogels is a promising approach to treating skin disorders such as melanoma.

METHODS

In this study, the chemical composition of Mentha pulegium essential oil with five major compounds, including pulegone (68.11%), l-menthone (8.83%), limonene (2.90%), iso-pulegone (2.69%), and iso-menthone (1.48%) was first identified using GC-MS (Gas chromatography-Mass Spectrometry) analysis. Afterward, a nano-scaled emulsion containing the essential oil with a droplet size of 7.70 ± 1 nm was prepared. Nanogel containing the essential oil was then prepared by adding (2% w/v) carboxymethyl cellulose to the nano-scaled emulsion. Moreover, the successful loading of M. pulegium essential oil in the nano-scaled emulsion and nanogel was confirmed using ATR-FTIR (Attenuated total reflectance-Fourier Transform InfraRed) analysis. Then, human A375 melanoma cells were treated with different concentrations of samples, the MTT assay evaluated cell viability, and cell apoptosis was confirmed by flow cytometry. In addition, the expression of apoptotic and anti-apoptotic genes, including Bax and Bcl-2, was evaluated using the qPCR (quantitative Polymerase Chain Reaction) technique.

RESULTS

The results showed that cell viability was reduced by 90 and 45% after treatment with 300 μg/mL of the nanogel and nano-scaled emulsion. As confirmed by flow cytometry, this effect was mediated by apoptosis. Furthermore, gene expression analysis showed up-regulation of Bax and down-regulation of Bcl-2 genes. Therefore, the prepared nanogel, with high efficacy, could be considered a potent anticancer agent for supplementary medicine and in vivo research.

Anticancer Applications of Essential Oils Formulated into Lipid-Based Delivery Nanosystems

The use of natural compounds is becoming increasingly popular among patients, and there is a renewed interest among scientists in nature-based bioactive agents. Traditionally, herbal drugs can be taken directly in the form of teas/decoctions/infusions or as standardized extracts. However, the disadvantages of natural compounds, especially essential oils, are their instability, limited bioavailability, volatility, and often irritant/allergenic potential. However, these active substances can be stabilized by encapsulation and administered in the form of nanoparticles. This brief overview summarizes the latest results of the application of nanoemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers used as drug delivery systems of herbal essential oils or used directly for their individual secondary metabolites applicable in cancer therapy. Although the discussed bioactive agents are not typical compounds used as anticancer agents, after inclusion into the aforesaid formulations improving their stability and bioavailability and/or therapeutic profile, they indicated anti-tumor activity and became interesting agents with cancer treatment potential. In addition, co-encapsulation of essential oils with synthetic anticancer drugs into nanoformulations with the aim to achieve synergistic effect in chemotherapy is discussed.

Antioxidative, anticancer, and antibacterial activities of a nanogel containing Mentha spicata L. essential oil and electrospun nanofibers of polycaprolactone-hydroxypropyl methylcellulose

BACKGROUND

As the largest organ, the skin has been frequently affected by trauma, chemical materials, toxins, bacterial pathogens, and free radicals. Recently, many attempts have been made to develop natural nanogels that, besides hydrating the skin, could also be used as antioxidant or antibacterial agents.

METHODS

In this study, the chemical composition of the Mentha spicata essential oil was first investigated using GC-MS analysis. Its nanoemulsion-based nanogel was then investigated; successful loading of the essential oil in the nanogel was confirmed using FTIR analysis. Besides, nanogel's antioxidative, anticancer, and antibacterial activities were investigated.

RESULTS

Carvone (37.1%), limonene (28.5%), borneol (3.9%), β-pinene (3.3%), and pulegone (3.3%) were identified as five major compounds in the essential oil. By adding carboxymethylcellulose (3.5% w/v) to the optimal nanoemulsion containing the essential oil (droplet size of 196 ± 8 nm), it was gelified. The viscosity was fully fitted with a common non-Newtonian viscosity regression, the Carreau-Yasuda model. The antioxidant effect of the nanogel was significantly more potent than the essential oil (P < 0.001) at all examined concentrations (62.5-1000 µg/mL). Furthermore, the potency of the nanogel with an IC50 value of 55.0 µg/mL was substantially more (P < 0.001) than the essential oil (997.4 µg/mL). Also, the growth of Staphylococcus aureus and Escherichia coli after treatment with 1000 µg/mL nanogel was about 50% decreased compared to the control group. Besides, the prepared electrospun polycaprolactone-hydroxypropyl methylcellulose nanofibers mat with no cytotoxic, antioxidant, or antibacterial effects was proposed as lesion dressing after treatment with the nanogel. High potency, natural ingredients, and straightforward preparation are advantages of the prepared nanogel. Therefore, it could be considered for further consideration in vivo studies.

Nanoemulsion and Nanogel Containing Eucalyptus globulus Essential Oil; Larvicidal Activity and Antibacterial Properties

Eucalyptus globulus essential oil (EGEO) possesses many biological effects such as antibacterial, antifungal, and insecticide properties. In the current study, the chemical composition of EGEO was first investigated using GC-MS analysis. Then, a nanoemulsion and nanogel containing EGEO (EGEO-nanoemulsion and EGEO-nanogel) were prepared. After that, the successful loading of EGEO was confirmed using ATR-FTIR analysis. EGEO-nanoemulsion and EGEO-nanogel with LC50 values of 27 and 32 μg/mL showed promising efficacies against Anopheles stephensi larvae. Besides, the efficacy of EGEO-nanogel (IC50 187 μg/mL) was significantly more potent than EGEO-nanoemulsion (IC50 3732 μg/mL) against Staphylococcus aureus. However, no significant difference was observed in the efficacy of EGEO-nanoemulsion and EGEO-nanogel against Pseudomonas aeruginosa. Natural components, straightforward preparation, and proper efficacy are some of the advantages of EGEO-nanogel; it could be considered for further consideration against other pathogens and mosquito larvae.

Cytotoxic effects of chitosan nanoparticles containing Zataria multiflora essential oil against human breast and melanoma cells

Background

Breast cancer is the most common cancer among women, and melanoma incidence increases worldwide. The emergence of drug resistance and side effects of chemotherapy drugs has led to a great deal of attention being paid to the development of natural medicines, especially using essential oil. The preparation of essential oil-based nanoformulation has thus recently received more attention.

Results

In this study, chitosan nanoparticles (ChiNPs) containing Zataria multiflora essential oil with a particle size of 177 ± 10 nm, a narrow particle size distribution (SPAN 0.96), and a cubic-like shape were first prepared. IC50 values of the prepared nanoformulation against human melanoma (A-375) and breast cancer cell lines (MCF-7 and MDA-MB-468) were obtained as 32 (12–84), 46 (32–67), and 105 (85–131) µg/mL. Besides, an electrospun polycaprolactone–polyethylene oxide scaffold was prepared as a dressing after treatment with the nanoformulation. Fourier transform infrared analysis confirmed the scaffold's preparation as well as successful loading of the essential oil in chitosan nanoparticles. Furthermore, the scaffold did not show a cytotoxic effect on A-375, MCF-7, and MDA-MB-468, and its surface was hydrophobic as the water contact angle with the surface was 136.5°.

Conclusions

The prepared prototype with natural ingredients and high efficacy could be considered for further consideration in vivo study or complementary medicine.

Graphical abstract