Essential oils as anticancer agents: Potential role in malignancies, drug delivery mechanisms, and immune system enhancement

Pistacia lentiscus L. revealed in vitro anti-proliferative activity on MCF-7 breast cancer cells and in vivo anti-mammary cancer effect on C57BL/6 mice through necrosis, anti-inflammatory and antioxidant enhancements

Inflammation and oxidative stress are two interconnected processes that play a role in cancer development and progression. In the present research, we aimed to evaluate the anticancer effect of Pistacia lentiscus L. (PL) essential oil (EO) in vitro against MCF-7 breast cancer cells and in vivo in DMBA-mammary cancer induction on female C57BL/6 mice model as well as to investigate its anti-inflammatory and antioxidant potential as implicated mechanism. Our results revealed a new chemotypes-profile of 39 bio-compounds of PL EO. The main chemotypes were terpenoid and ketone compounds. In vitro, PL EO had a potent anti-proliferative activity against MCF-7 cells. In vivo, PL reduced the tumor number, volume, weight and burden values as compared to the DMBA-positive control group (p<0.05). Histopathology data confirmed the protective effect of PL traduced by the presence of necrosis area. PL EO revealed improvement on inflammatory perturbation in the C-RP levels and the complete blood cell count. Finally, PL improved oxidative disorders of lipid peroxidation, thiol groups, hydrogen peroxide and antioxidant enzymes depletion in plasma and mammary tissues. Also, a potent plasma scavenging capacity has been detected. Our data suggested that PL chemotypes inhibited cell proliferation, exerting a potential protective effect against DMBA-mammary cancer through anti-inflammatory and antioxidant enhancements. Targeting inflammation and oxidative stress may represent a promising strategy for breast cancer prevention and treatment.

Development of Curcumin and Turmerone Loaded Solid Lipid Nanoparticle for Topical Delivery: Optimization, Characterization and Skin Irritation Evaluation with 3D Tissue Model

Background

Curcuma longa L., commonly known as turmeric, is renowned for its therapeutic benefits attributed to bioactive compounds, namely curcumin (Cur) and aromatic turmerone (Tur), present in its rhizome. These compounds exhibit diverse therapeutic properties, including anti-inflammatory, antioxidant, and anti-tumor effects. However, the topical application of these compounds has a significant potential for inducing skin irritation. This study focuses on formulating solid lipid nanoparticle (SLN) carriers encapsulating both Cur and Tur for reduced irritation and enhanced stability.

Methods

SLN formulations were prepared by a method using homogenization followed by ultrasonication procedures and optimized by applying response surface methodology (RSM).

Results

The optimized SLN formulation demonstrated entrapment efficiencies, with 77.21 ± 4.28% for Cur and 75.12 ± 2.51% for Tur. A size distribution of 292.11 ± 9.43 nm was obtained, which was confirmed to be a spherical and uniform shape via environmental scanning electron microscopy (ESEM) images. The in vitro release study indicated cumulative releases of 71.32 ± 3.73% for Cur and 67.23 ± 1.64% for Tur after 24 hours under sink conditions. Physical stability tests confirmed the stability of formulation, allowing storage at 4°C for a minimum of 60 days. Notably, in vitro skin irritation studies, utilizing the reconstructed human epidermal model (EPI-200-SIT), revealed a significant reduction in irritation with the SLN containing Cur and Tur compared to nonencapsulated Cur and Tur.

Conclusion

These findings collectively endorse the optimized SLN formulation as a favorable delivery system for Cur and Tur in diverse topical uses, offering enhanced stability, controlled release and reduced irritation.

Peanut oil odor enhances the immunomodulatory effect on immunosuppressed mice by regulating the cAMP signaling pathway via the brain-spleen axis

The role of sniffing relative to immune function has attracted considerable attention. The present study investigated the immunomodulatory effects of peanut oil odor on cyclophosphamide (CTX)-induced immunosuppressed mice. The subset of mice subjected to prolonged (8 h) sniffing peanut oil odor (PL) demonstrated significantly elevated levels of agouti-related peptide, neuropeptide Y, and glutamate (p < 0.05), whereas it significantly down-regulated the level of γ-aminobutyric acid in the brain (p < 0.05). Furthermore, immunohistochemistry results indicated significantly increased expression of mGluR1/5 and decreased expression of GABABR in the hippocampus and hypothalamus (p < 0.05) of the PL group. Additionally, the PL group had significantly up-regulated expression levels of cAMP, Epac, Rap1, ERK1/2 and PKA (p < 0.05) and remarkably increased phosphorylation of CREB in the cAMP signaling pathway (p < 0.05), which influenced the central nervous system. Moreover, compared with CTX-induced mice, the percentages of peripheral blood T lymphocytes (CD3+CD4+ and CD3+CD8+) and the levels of splenic cytokines (IL-2, IL-4, and TNF-α) were significantly increased following PL treatment (p < 0.05). The PL group also showed significantly up-regulated expression levels of cAMP, p-p65, and p-IκBα in the spleen (p < 0.05) by western blot analysis. In summary, PL intervention significantly up-regulated the expression levels of cAMP in the brain (p < 0.05), with subsequent transfer of cAMP to the spleen which promoted phosphorylation of p65 and IκBα. This series of events enhanced the immunity of mice, which confirmed the regulatory effect of PL on the cAMP signaling pathway, thereby enhancing immune function via the brain-spleen axis.

Chitosan-Based Nanoencapsulated Essential Oils: Potential Leads against Breast Cancer Cells in Preclinical Studies

Since ancient times, essential oils (EOs) derived from aromatic plants have played a significant role in promoting human health. EOs are widely used in biomedical applications due to their medicinal properties. EOs and their constituents have been extensively studied for treating various health-related disorders, including cancer. Nonetheless, their biomedical applications are limited due to several drawbacks. Recent advances in nanotechnology offer the potential for utilising EO-loaded nanoparticles in the treatment of various diseases. In this aspect, chitosan (CS) appears as an exceptional encapsulating agent owing to its beneficial attributes. This review highlights the use of bioactive EOs and their constituents against breast cancer cells. Challenges associated with the use of EOs in biomedical applications are addressed. Essential information on the benefits of CS as an encapsulant, the advantages of nanoencapsulated EOs, and the cytotoxic actions of CS-based nanoencapsulated EOs against breast cancer cells is emphasised. Overall, the nanodelivery of bioactive EOs employing polymeric CS represents a promising avenue against breast cancer cells in preclinical studies.

Essential oils and their nanoformulations for breast cancer therapy

Breast Cancer (BC) is the most prevalent type of cancer in the world. Current treatments include surgery, radiation, and chemotherapy but often are associated with high toxicity to normal tissues, chemoresistance, and relapse. Thus, developing novel therapies which could combat these limitations is essential for effective treatment. In this context, phytochemicals are increasingly getting popular due to their safety profile, ability to efficiently target tumors, and circumvent limitations of existing treatments. Essential Oils (EOs) are mixtures of various phytochemicals which have shown potential anticancer activity in preclinical BC models. However, their clinical translation is limited by factors such as high volatility, low stability, and poor solubility. Nanotechnology has facilitated their encapsulation in a variety of nanostructures and proven to overcome these limitations. In this review, we have efficiently summarized the current knowledge on the anticancer effect of EOs and constituents in both in in vitro and in in vivo BC models. Further, we also provide a descriptive account on the potential of nanotechnology in enhancing the anti-BC activity of EOs and their constituents. The papers discussed in this review were selected using the keywords "antiproliferative Essential Oils in breast cancer," "anticancer activity of Essential Oil in breast cancer," and "cytotoxicity of Essential Oils in breast cancer" performed in PubMed and ScienceDirect databases.

Structured soft particulate matters for delivery of bioactive compounds in foods and functioning in the colon

The present review discusses challenges, perspectives, and current needs of delivering bioactive compounds (BCs) using soft particulate matters (SPMs) for gut health. SPMs can entrap BCs for incorporation in foods, preserve their bioactivities during processing, storage, and gastrointestinal digestion, and deliver BCs to functioning sites in the colon. To enable these functions, physical, chemical, and biological properties of BCs are integrated in designing various types of SPMs to overcome environmental factors reducing the bioavailability and bioactivity of BCs. The design principles are applied using food grade molecules with the desired properties to produce SPMs by additionally considering the cost, sustainability, and scalability of manufacturing processes. Lastly, to make delivery systems practical, impacts of SPMs on food quality are to be evaluated case by case, and health benefits of functional foods incorporated with delivery systems are to be confirmed and must outweigh the cost of preparing SPMs.

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.

New insights into the cytotoxic effects of Thymus vulgaris essential oil on the human triple-negative breast cancer cell line MDA-MB-231

Essential oils (EOs) are natural products that have gained wide interest due to their biological activities and anticancer properties through various mechanisms. The present study aimed to test the cytotoxicity of Thymus vulgaris L. (thyme) EO of Italian origin, rich in thymol (49.6%) and p-cymene (18.8%), towards the triple-negative breast cancer cell line MDA-MB-231 and to investigate the biochemical mechanisms underlying its antitumor activity. Thyme EO reduced cancer cell viability in a dose-dependent manner after 24 h treatment, with an IC50 value equal to 75.1 ± 15.2 μg/ml; simultaneously, the inhibition of cancer cell migration and colony formation capacity was evidenced. Thyme EO antiproliferative effects were related to the induction of apoptosis as demonstrated by the increased expression of the pro-apoptotic proteins Bax, cleaved caspase-3, phospho-p53, and SMAC/Diablo and by the reduction of the anti-apoptotic proteins Bcl-2, cIAP-1, cIAP-2, HIF-1α, survivin, and XIAP. Thyme EO administration led to the early formation of intracellular ROS, followed by the increment of MDA as an index of lipid peroxidation and by the decreased expression of the antioxidant enzymes catalase and PON2. The upregulation of Nrf2 mRNA expression and the strong induction of HO-1 sustained the activation of the Nrf2 pathway by thyme EO. These data showed that the EO from Thymus vulgaris L. might inhibit the malignant phenotype of MDA-MB-231, thus suggesting potential benefits against human triple-negative breast cancer.

Chemical profile, antiproliferative and pro-apoptotic activities of essential oils of Pulicaria arabica against A549 lung cancer cell line

Pulicaria arabica has been traditionally utilized in folk medicine for various purposes such as ulcer treatments as well as antidiarrheal agent. Herein, the chemical profiles of Pulicaria arabica essential oils (PAEOs) and the in vitro antiproliferative effect of PAEOs were investigated. Hydrodistillation was employed to prepare PAEOs which were then characterized by GC/MS, while the antiproliferative effects were investigated by MTT assay as well as flow cytometric and RT-PCR analysis. Sixty-four (99.99 %) constituents were recognized from PAEOs. Carvotanacetone (36.97 %), (-)-carvomenthone (27.20 %) and benzene, 2-(1,1-dimethylethyl)-1,4-dimethoxy- (6.92 %) were the main components. PAEOs displayed IC50 values ranging from 30 to 50 μg/mL. DNA content analysis revealed that A549 cells exposed to PAEOs exhibited an increase in G1 cells population. The flow cytometry analysis results also showed that the PAEOs antiproliferative effect was mediated via apoptosis induction. Furthermore, a modulation in the pro-apoptotic markers (caspase-3 and Bax) and anti-apoptotic (Bcl-2) was also observed. In conclusion, PAEOs exhibited a moderate anti-proliferative effect on A549 cells through modulating the cell cycle progression and apoptosis initiation. These findings could offer a potential therapeutic use of PAEOs in lung cancer treatment.

Comparison of chitosan nanoparticles containing Lippia citriodora essential oil and citral on the induction of apoptosis in A375 melanoma cells

BACKGROUND

Using nanoparticles containing L. citriodora EO and citral has shown potential in treating skin disorders such as melanoma.

METHODS

In this study, GC‒MS was used to analyze the chemical composition of L. citriodora essential oil (EO). The ion gelation method prepared free chitosan nanoparticles and chitosan nanoparticles containing L. citriodora EO and citral. The successful loading of the EO and citral was evaluated using ATR-FTIR. The DPPH assay measured the antioxidant effect of citral, L. citriodora EO, Citral-ChiNPs, L. citriodora-ChiNPs, and Free-ChiNPs. A375 melanoma cell viability was assessed using the MTT assay. The qPCR technique was employed to evaluate the expression of apoptotic genes, and flow cytometry was used to detect apoptosis.

RESULTS

This study showed that in equal concentrations, the antioxidant properties of chitosan nanoparticles containing citral were greater than those of chitosan nanoparticles containing L. citriodora. The IC50 values of chitosan nanoparticles containing citral, L. citriodora EO, and their nonformulated states were 105.6, 199.9, 136.9, and 240 µg/ml, respectively. The gene expression results showed that the ratio of the expression of the apoptosis gene to the inhibitory gene was higher than 1 in all the samples, indicating that the conditions for apoptosis were present. Flow cytometry confirmed cell apoptosis, with 93.5 ± 0.3% in chitosan nanoparticles containing citral, 80 ± 0.2% in chitosan nanoparticles containing L. citriodora EO, 63 ± 0.3 in citral, and 42.03% in L. citriodora EO-treated cells.

CONCLUSION

The results showed that using the Nano form of L. citriodora and citral increased their efficiency in apoptosis pathways and their toxicity against 375 melanoma cancer cells.

Chemical composition and biological activities of essential oil from Grewia bulot leaves

This study focused on the chemical composition and biological activities of the essential oil derived from Grewia bulot, a plant species known for its medicinal properties. The analysis of Grewia bulot essential oil revealed the presence of 78 constituents. The major compounds were α-cadinol (13.5%), 1,8-cineole (12.7%), 1,10-di-epi-cubenol (9.8%), epi-α-cadinol (6.7%), (E,E)-α-farnesene (5.9%), (E)-citral (4.0%), selin-11-en-4-α-ol (4.0%), citronellol isobutanoate (3.9%), and geranic acid (3.7%). The essential oil exhibited promising antioxidant potential with an IC50 value of 452.65 ± 28.40 µg/mL in DPPH model. This oil did not show NO production inhibitory effect in RAW 264.7 cells. In addition, the essential oil exhibited significant cytotoxicity against KB, Hep-G2, MCF-7, and SK-LU-1 cancer cell lines, with IC50 values ranging from 44.04 ± 1.47 to 74.20 ± 3.71 μg/mL.

Enhanced Natural Strength: Lamiaceae Essential Oils and Nanotechnology in In Vitro and In Vivo Medical Research

The Lamiaceae is one of the most important families in the production of essential oils known to have a wide spectrum of biological activity. Recent research has highlighted the dermatological capabilities of various Lamiaceae essential oils, which appear to offer potential in free radical scavenging and anti-inflammatory activity. Some have also been extensively studied for their tissue remodeling and wound-healing, anti-aging, anti-melanogenic, and anti-cancer properties. Certain Lamiaceae essential oils are promising as novel therapeutic alternatives for skin disorders. This potential has seen substantial efforts dedicated to the development of modern formulations based on nanotechnology, enabling the topical application of various Lamiaceae essential oils. This review provides a comprehensive summary of the utilization of various essential oils from the Lamiaceae family over the past decade. It offers an overview of the current state of knowledge concerning the use of these oils as antioxidants, anti-inflammatory agents, wound-healers, anti-aging agents, anti-melanogenic agents, and anticancer agents, both alone and in combination with nanoparticles. Additionally, the review explores their potential applicability in patents regarding skin diseases.

Unveiling the Chemical Profiling Antioxidant and Anti-Inflammatory Activities of Algerian Myrtus communis L. Essential Oils, and Exploring Molecular Docking to Predict the Inhibitory Compounds against Cyclooxygenase-2

Considering the large spectrum of side effects caused by synthetic drugs and the development of natural alternatives utilizing Algerian flora, this study aimed to place a spotlight on the chemical profile and antioxidant and anti-inflammatory activities of Myrtus communis L. essential oils (MCEOs). In this study, essential oils (EOs) were collected via hydro-distillation of the plant's leaves, and a chemical constituent analysis was performed using gas chromatography-mass spectrophotometry (GC-MS). The in vitro antioxidant activity was evaluated using DPPH, ABTS, and hydroxyl radical scavenging tests. The in vitro anti-inflammatory capacity was estimated by studying the antidenaturation effect using bovine serum albumin (BSA) as a protein model. The in vivo anti-inflammatory activity was carried out by utilizing the classical model of carrageenan-induced paw edema in rats, using diclofenac (DCF) as the reference drug. Moreover, the molecular interaction of the compounds obtained from the GC-MS analysis was studied within the binding site of cyclooxygenase-2 (COX-2) using an in silico approach as the confirmatory tool of the in vitro and in vivo experiments. The GC-MS analysis revealed that MCEOs were mainly composed of oxygenated monoterpenes (70.56%), oxygenated sesquiterpenes (3.1%), sesquiterpenes (4.17%), and monoterpenes (8.75%). Furthermore, 1,8-cineole was the major compound (19.05%), followed by cis-geranyl acetate (11.74%), methyl eugenol (5.58%), α-terpineol (4.62%), and β-myrcene (4.40%). MCEOs exhibited remarkable concentration-dependent free radical scavenging activity, with an IC50 of 15.317 ± 0.340 µg/mL, 18.890 ± 2.190 µg/mL, and 31.877 ± 0.742 µg/mL for DPPH, ABTS, and hydroxyl radical, respectively. The significant in vitro anti-inflammatory activity due to the inhibition of BSA denaturation was proportional to the EO concentration, where the highest value was recorded at 100 μg/mL with an approximately 63.35% percentage inhibition and an IC50 of 60.351 ± 5.832 μg/mL. MCEOs showed a good in vivo anti-inflammatory effect by limiting the development of carrageenan-induced paw thickness. The in silico study indicated that, among the 60 compounds identified by the GC-MS analysis, 9 compounds were observed to have a high binding energy to cyclooxygenase-2 as compared to diclofenac. Our study revealed that EOs from Algerian Myrtus communis L. can be considered to be a promising candidate for alleviating many debilitating health problems and may provide new insights in the fields of drug design, agriculture, and the food industry.

Chemical Composition and In Vitro Evaluation of Antioxidant and Antiproliferative Effects of Volatile Oils Hydrodistilled from Onobrychis carduchorum C.C. Towns., a Kurdish Traditional Plant

The volatile oils hydrodistilled from the aerial parts and roots of O. carduchorum C.C Towns. (Fabaceae) have been chemically characterized for the first time. A total of 43 constituents with an abundance >0.03% were identified and quantified in the two oils by GC/MS and GC/FID analyses. They comprise 38 components (98.58%) of the oil isolated from the aerial parts (OCA) and 34 components (93.33%) of the oil from the roots (OCR). Six constituents, α-pinene (23.11 ± 0.1%), β-elemene (17.33 ± 0.1%), 1,8-cineole (12.15 ± 0.2%), furfural (7.91 ± 0.1%), terpineol-4-ol (6.32 ± 0.2%), and limonene (4.13 ± 0.1%), accounted for about 75% of the total OCA oil. On the other hand, 1,8-cineole (15.79 ± 0.1%), furfural (10.44 ± 0.1%), β-elemene (10.14 ± 0.2%), α-terpineol (7.74 ± 0.1%), linalool (7.45 ± 0.1%), and α-pinene (4.76 ± 0.1%) made up about 60% of the OCR oil. The IC50 values of the scavenging activities of the OCA and OCR oils towards the DPPH radical and H2O2 were 79.8 ± 0.5 and 153.3 ± 0.6 μg/mL and 394.09 ± 0.2 and 311.67 ± 0.4 μg/mL, respectively. In addition, in the MTS assay, the OCA and OCR oils showed significant antiproliferative effects against T47D, MDA-MB-453, BG-1, and A549 human cancer cells that were more powerful than those against two normal human cell lines, HEK-293 and HFF-1. The abundant presence of β-elemene as an antiproliferative component of the two oils suggested the existence of a new chemotype of O. carduchorum.

Plant Essential Oils as Biopesticides: Applications, Mechanisms, Innovations, and Constraints

The advent of the "Green Revolution" was a great success in significantly increasing crop productivity. However, it involved high ecological costs in terms of excessive use of synthetic agrochemicals, raising concerns about agricultural sustainability. Indiscriminate use of synthetic pesticides resulted in environmental degradation, the development of pest resistance, and possible dangers to a variety of nontarget species (including plants, animals, and humans). Thus, a sustainable approach necessitates the exploration of viable ecofriendly alternatives. Plant-based biopesticides are attracting considerable attention in this context due to their target specificity, ecofriendliness, biodegradability, and safety for humans and other life forms. Among all the relevant biopesticides, plant essential oils (PEOs) or their active components are being widely explored against weeds, pests, and microorganisms. This review aims to collate the information related to the expansion and advancement in research and technology on the applications of PEOs as biopesticides. An insight into the mechanism of action of PEO-based bioherbicides, bioinsecticides, and biofungicides is also provided. With the aid of bibliometric analysis, it was found that ~75% of the documents on PEOs having biopesticidal potential were published in the last five years, with an annual growth rate of 20.51% and a citation per document of 20.91. Research on the biopesticidal properties of PEOs is receiving adequate attention from European (Italy and Spain), Asian (China, India, Iran, and Saudi Arabia), and American (Argentina, Brazil, and the United States of America) nations. Despite the increasing biopesticidal applications of PEOs and their widespread acceptance by governments, they face many challenges due to their inherent nature (lipophilicity and high volatility), production costs, and manufacturing constraints. To overcome these limitations, the incorporation of emerging innovations like the nanoencapsulation of PEOs, bioinformatics, and RNA-Seq in biopesticide development has been proposed. With these novel technological interventions, PEO-based biopesticides have the potential to be used for sustainable pest management in the future.

Essential oil of lemon myrtle (Backhousia citriodora) induces S-phase cell cycle arrest and apoptosis in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Lemon myrtle (Backhousia citriodora F.Muell.) leaves, whether fresh or dried, are used traditionally in folk medicine to treat wounds, cancers, skin infections, and other infectious conditions. However, the targets and mechanisms related to anti-cancer effect of lemon myrtle are unavailable. In our study, we found that the essential oil of lemon myrtle (LMEO) showed anti-cancer activity in vitro, and we initially explored its mechanism of action.

MATERIALS AND METHODS

We analyzed the chemical compositions of LMEO by GC-MS. We tested the cytotoxicity of LMEO on various cancer cell lines using the MTT assay. Network pharmacology was used also to analyze the targets of LMEO. Moreover, the mechanisms of LMEO were investigated through scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line.

RESULTS

LMEO showed cytotoxicity on various cancer cell lines with values of IC₅₀ 40.90 ± 2.23 (liver cancer HepG2 cell line), 58.60 ± 6.76 (human neuroblastoma SH-SY5Y cell line), 68.91 ± 4.62 (human colon cancer HT-29 cell line) and 57.57 ± 7.61 μg/mL (human non-small cell lung cancer A549 cell line), respectively. The major cytotoxic chemical constituent in LMEO was identified as citrals, which accounted for 74.9% of the content. Network pharmacological analysis suggested that apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1), androgen receptor (AR), cyclin-dependent kinases 1 (CDK1), nuclear factor erythroid 2-related factor 2 (Nrf-2), fatty acid synthase (FASN), epithelial growth factor receptor (EGFR), estrogen receptor 1 (ERα) and cyclin-dependent kinases 4 (CDK4) are potential cytotoxic targets of LMEO. These targets are closely related to cell migration, cycle and apoptosis. Notley, the p53 protein had the highest confidence to co-associate with the eight common targets, which was further confirmed by scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line. LMEO significantly inhibited the migration of HepG2 cells in time-dependent and dose-dependent manner. Moreover, LMEO caused a S-phase blocking on HepG2 cells and promoted apoptosis in the meanwhile. Western blot results indicated that p53 protein, Cyclin A2 and Bax proteins were up-regulated, while Cyclin E1 and Bcl-2 proteins were down-regulated.

CONCLUSION

LMEO showed cytotoxicity in various cancer cell lines in vitro. Pharmacological networks showed LMEO to have multi-component and multi-targeting effects that are related to inhibit migration of HepG2 cells, and affect cell cycle S-phase arrest and apoptosis through modulation of p53 protein.

Cytotoxic Screening and Enhanced Anticancer Activity of Lippia alba and Clinopodium nepeta Essential Oils-Loaded Biocompatible Lipid Nanoparticles against Lung and Colon Cancer Cells

Plant and herbal essential oils (EOs) offer a wide range of pharmacological actions that include anticancer effects. Here, we evaluated the cytotoxic activity of EO from Lippia alba (chemotype linalool), L. alba (chemotype dihydrocarvone, LaDEO), Clinopodium nepeta (L.) Kuntze (CnEO), Eucalyptus globulus, Origanum × paniculatum, Mentha × piperita, Mentha arvensis L., and Rosmarinus officinalis L. against human lung (A549) and colon (HCT-116) cancer cells. The cells were treated with increasing EO concentrations (0-500 µL/L) for 24 h, and cytotoxic activity was assessed. LaDEO and CnEO were the most potent EOs evaluated (IC50 range, 145-275 µL/L). The gas chromatography-mass spectrometry method was used to determine their composition. Considering EO limitations as therapeutic agents (poor water solubility, volatilization, and oxidation), we evaluated whether LaDEO and CnEO encapsulation into solid lipid nanoparticles (SLN/EO) enhanced their anticancer activity. Highly stable spherical SLN/LaDEO and SLN/CnEO SLN/EO were obtained, with a mean diameter of 140-150 nm, narrow size dispersion, and Z potential around -5mV. EO encapsulation strongly increased their anticancer activity, particularly in A549 cells exposed to SLN/CnEO (IC50 = 66 µL/L CnEO). The physicochemical characterization, biosafety, and anticancer mechanisms of SLN/CnEO were also evaluated in A549 cells. SLN/CnEO containing 97 ± 1% CnEO was highly stable for up to 6 months. An increased in vitro CnEO release from SLN at an acidic pH (endolysosomal compartment) was observed. SLN/CnEO proved to be safe against blood components and non-toxic for normal WI-38 cells at therapeutic concentrations. SLN/CnEO substantially enhanced A549 cell death and cell migration inhibition compared with free CnEO.

Antibacterial and Antibiofilm Effects of Different Samples of Five Commercially Available Essential Oils

Essential oils (EOs) have gained economic importance due to their biological activities, and increasing amounts are demanded everywhere. However, substantial differences between the same essential oil samples from different suppliers are reported-concerning their chemical composition and bioactivities-due to numerous companies involved in EOs production and the continuous development of online sales. The present study investigates the antibacterial and antibiofilm activities of two to four samples of five commercially available essential oils (Oregano, Eucalyptus, Rosemary, Clove, and Peppermint oils) produced by autochthonous companies. The manufacturers provided all EOs' chemical compositions determined through GC-MS. The EOs' bioactivities were investigated in vitro against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The antibacterial and antibiofilm effects (ABE% and, respectively, ABfE%) were evaluated spectrophotometrically at 562 and 570 nm using microplate cultivation techniques. The essential oils' calculated parameters were compared with those of three standard broad-spectrum antibiotics: Amoxicillin/Clavulanic acid, Gentamycin, and Streptomycin. The results showed that at the first dilution (D1 = 25 mg/mL), all EOs exhibited antibacterial and antibiofilm activity against all Gram-positive and Gram-negative bacteria tested, and MIC value > 25 mg/mL. Generally, both effects progressively decreased from D1 to D3. Only EOs with a considerable content of highly active metabolites revealed insignificant differences. E. coli showed the lowest susceptibility to all commercially available essential oils-15 EO samples had undetected antibacterial and antibiofilm effects at D2 and D3. Peppermint and Clove oils recorded the most significant differences regarding chemical composition and antibacterial/antibiofilm activities. All registered differences could be due to different places for harvesting the raw plant material, various technological processes through which these essential oils were obtained, the preservation conditions, and complex interactions between constituents.

Waste Citrus limon Leaves as Source of Essential Oil Rich in Limonene and Citral: Chemical Characterization, Antimicrobial and Antioxidant Properties, and Effects on Cancer Cell Viability

This study investigated chemical composition, cytotoxicity in normal and cancer cells, and antimicrobial and antioxidant activity of the essential oil (EO) isolated by hydrodistillation from the discarded leaves of lemon (Citrus limon) plants cultivated in Sardinia (Italy). The volatile chemical composition of lemon leaf EO (LLEO) was analyzed with gas chromatography-mass spectrometry combined with flame ionization detection (GC/MS and GC/FID). The most abundant component of LLEO was limonene (260.7 mg/mL), followed by geranial (102.6 mg/mL) and neral (88.3 mg/mL). The antimicrobial activity of LLEO was tested using eight bacterial strains and two types of yeasts by a microdilution broth test. Candida albicans showed the greatest susceptibility (MIC = 0.625 μL/mL) and Listeria monocytogenes and Staphylococcus aureus were inhibited at low LLEO concentration (MIC values from 2.5 to 5 μL/mL). The C. limon leaf EO displayed radical scavenging ability (IC₅₀ value of 10.24 mg/mL) in the 2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) assay. Furthermore, the LLEO impact on cell viability was explored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in cancer HeLa cells, A375 melanoma cell line, normal fibroblasts (3T3 cells), and keratinocytes (HaCaT cells). LLEO, at 24 h of incubation, significantly reduced viability from 25 μM in Hela cells (33% reduction) and A375 cells (27%), greatly affecting cell morphology, whereas this effect was found from 50 μM on 3T3 fibroblasts and keratinocytes. LLEO's pro-oxidant effect was also established in HeLa cells by 2',7'-dichlorodihydrofluorescein diacetate assay.

Co-Delivery of Ylang Ylang Oil of Cananga odorata and Oxaliplatin Using Intelligent pH-Sensitive Lipid-Based Nanovesicles for the Effective Treatment of Triple-Negative Breast Cancer

Smart pH-responsive niosomes loaded with either Oxaliplatin (Ox), Ylang ylang essential oil (Y-oil), or co-loaded with both compounds (Ox-Y) (Ox@NSs, Y@NSs, and Ox-Y@NSs, respectively) were formulated utilizing the thin film method. The developed nanocontainers had a spherical morphology with mean particle sizes lower than 170 nm and showed negative surface charges, high entrapment efficiencies, and a pH-dependent release over 24 h. The prepared pH-responsive niosomes' cytotoxicity was tested against the invasive triple-negative breast cancer (MDA-MB-231) cells, compared to free OX and Y-oil. All niosomal formulations loaded with Ox and/or Y-oil significantly improved cytotoxic activity relative to their free counterparts. The Ox-Y@NSs demonstrated the lowest IC50 (0.0002 µg/mL) when compared to Ox@NSs (0.006 µg/mL) and Y@NSs (18.39 µg/mL) or unloaded Ox (0.05 µg/mL) and Y-oil (29.01 µg/mL). In addition, the percentages of the MDA-MB-231 cell population in the late apoptotic and necrotic quartiles were profoundly higher in cells treated with the smart Ox-Y@NSs (8.38% and 5.06%) than those exposed to free Ox (7.33% and 1.93%) or Y-oil (2.3% and 2.13%) treatments. Gene expression analysis and protein assays were performed to provide extra elucidation regarding the molecular mechanism by which the prepared pH-sensitive niosomes induce apoptosis. Ox-Y@NSs significantly induced the gene expression of the apoptotic markers Tp53, Bax, and Caspase-7, while downregulating the antiapoptotic Bcl2. As such, Ox-Y@NSs are shown to activate the intrinsic pathway of apoptosis. Moreover, the protein assay ascertained the apoptotic effects of Ox-Y@NSs, generating a 4-fold increase in the relative protein quantity of the late apoptotic marker Caspase-7. Our findings suggest that combining natural essential oil with synthetic platinum-based drugs in pH-responsive nanovesicles is a promising approach to breast cancer therapy.

Effects of Essential Oils and Fragrant Compounds on Appetite: A Systematic Review

Appetite dysregulation is one of the factors contributing to anorexia, bulimia nervosa, obesity, and diabetes. Essential oils or fragrant compounds have been proven to regulate food intake and energy expenditure; hence, this study aimed to summarize their effects on appetite and the underlying mechanisms. The PubMed and Web of Science databases were searched until July 2022. Only two of the 41 studies were performed clinically, and the remaining 39 used animal models. Oral administration was the most common route, and a dosage range of 100-2000 mg/kg for mice or 2-32 mg/kg for rats was applied, with a duration of 12 days to 4 weeks, followed by inhalation (10^-6-10^-3 mg/cage or 10^-9-10^-2 mg/cm³ within 1 h). Approximately 11 essential oil samples and 22 fragrant compounds were found to increase appetite, while 12 essential oils and seven compounds decreased appetite. These fragrant components can exert appetite-regulating effects via leptin resistance, the activity of sympathetic/parasympathetic nerves, or the mRNA expression of neuropeptide Y (NPY)/agouti-related protein (AgRP), cocaine- and amphetamine-regulated transcript (CART)/proopiomelanocortin (POMC) in the hypothalamus. Fragrance memory and cognitive processes may also play roles in appetite regulation. The findings of this study accentuate the potential of essential oils and fragrant compounds to regulate appetite and eating disorders.

Citrus Essential Oils: A Rational View on its Chemical Profiles, Mode of Action of Anticancer Effects/Antiproliferative Activity on Various Human Cancer Cell Lines

Cancer is a complex genetic disorder due to uncontrolled growth of abnormal cells in the body, causes damage to the immune system, and may lead to life-threatening situations. Common approaches to cancer treatment includes chemotherapy, hormone therapy, immunotherapy, radiation therapy etc. Development of novel and natural chemotherapeutic agents is highly demanded because of the side effects of synthetic drugs. Essential oils from aromatic plants exhibited antioxidant, antimutagenic, antiproliferative and immunomodulating activities. Mechanism of multidrug resistance and synergistic action of these volatile constituents are responsible for their chemopreventive properties. These oils primarily comprising of terpenoid constituents and are characterized by volatility, aroma, low molecular weight etc. The chemical composition of these oils varies depending on the environmental condition, species, plant part and geographical region. Literature analysis revealed that plant essential oils play an important role in cancer prevention and treatment. Cancer patients exposed to essential oils via inhaler devices were found to have less anxiety, stress, and nausea and insomnia. Nowadays, there is an increasing demand for investigating the biological properties of aromatic plants due to their availability, chemical diversity, and low toxicity. In aromatherapy, Citrus essential oils repress cancer related pain and enhance immune system. Current review summarizes existing variability of the chemical composition of Citrus essential oils and its molecular level anticancer mechanism against various human cancer cell lines. Citrus essential oils enhance cytotoxicity, antiproliferative and apoptotic behavior of cancer cell lines. Since essential oils exhibiting significant anticancer potential is worthy of further investigation for cancer chemoprevention. The findings of various research activities can be exploited by cancer researchers world wide for the development of anticancer drugs which can relieve cancer symptoms.

Nanostructured Lipid Carrier-Based Gel for Repurposing Simvastatin in Localized Treatment of Breast Cancer: Formulation Design, Development, and In Vitro and In Vivo Characterization

Simvastatin (SMV) is noticed as a repurposed candidate to be effective against breast cancer (BC). However, poor solubility, dose-limiting toxicities, and side effects are critical hurdles in its use against BC. The above drawbacks necessitate the site-specific (localized) delivery of SMV via suitable nanocarriers. Therefore, the present study intended to develop SMV nanostructured lipid carrier (NLC)-based gel using carbopol-934 as a gelling agent to achieve local delivery and improve patient compliance while combating BC. The SMV NLCs were fabricated by melt-emulsification ultrasonication technique using stearic acid as solid lipid, olive oil (OO) as liquid lipid, tween 20 as a surfactant, and PEG-200 as a co-surfactant, and optimized by Box-Behnken design. The optimized SMV-loaded NLCs displayed % entrapment efficiency of 91.66 ± 5.2% and particle size of 182 ± 11.9 nm. The pH of NLC-based gels prepared using a 2.0% w/v of carbopol-934 was found in the range of 5.3-5.6 while the viscosity was in the range of 5.1-6.6 Pa.S. Besides, NLC-based gels exhibited higher and controlled SMV release (71-76%) at pH 6.8 and (78-84%) at pH 5.5 after 48 h than SMV conventional gel (37%) at both pH 6.8 and 5.5 after 48 h. The ex vivo permeation of SMV from NLC-based gel was 3.8 to 4.5 times more than conventional gel. Notably, SMV-loaded NLCs displayed ameliorated cytotoxicity than plain SMV against MCF-7 and MDA-MB-231 BC cells. No substantial difference was noticed in the cytotoxicity of NLC-based gels and pure SMV against both cell lines. The SMV NLC-based gel exhibited the absence of skin irritation in vivo in the mice following topical application. In addition, the histopathological study revealed no alteration in the mice skin anatomy. Furthermore, the SMV-loaded NLCs and NLC-based gels were stable for 6 months at refrigerator conditions (4°C ± 2°C). Thus, the present research confirms that NLC-based gel can be a safe, efficacious, and novel alternative to treat BC.

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.

Chitosan nanocarriers containing essential oils as a green strategy to improve the functional properties of chitosan: A review

Large amounts of agricultural waste, especially marine product waste, are produced annually. These wastes can be used to produce compounds with high-added value. Chitosan is one such valuable product that can be obtained from crustacean wastes. Various biological activities of chitosan and its derivatives, especially antimicrobial, antioxidant, and anticancer properties, have been confirmed by many studies. The unique characteristics of chitosan, especially chitosan nanocarriers, have led to the expansion of using chitosan in various sectors, especially in biomedical sciences and food industries. On the other hand, essential oils, known as volatile and aromatic compounds of plants, have attracted the attention of researchers in recent years. Like chitosan, essential oils have various biological activities, including antimicrobial, antioxidant, and anticancer. In recent years, one of the ways to improve the biological properties of chitosan is to use essential oils encapsulated in chitosan nanocarriers. Among the various biological activities of chitosan nanocarriers containing essential oils, most studies conducted in recent years have been in the field of antimicrobial activity. It was documented that the antimicrobial activity was increased by reducing the size of chitosan particles in the nanoscale. In addition, the antimicrobial activity was intensified when essential oils were in the structure of chitosan nanoparticles. Essential oils can increase the antimicrobial activity of chitosan nanoparticles with synergistic effects. Using essential oils in the structure of chitosan nanocarriers can also improve the other biological properties (antioxidant and anticancer activities) of chitosan and increase the application fields of chitosan. Of course, using essential oils in chitosan nanocarriers for commercial use requires more studies, including stability during storage and effectiveness in real environments. This review aims to overview recent studies on the biological effects of essential oils encapsulated in chitosan nanocarriers, with notes on their biological mechanisms.

The In Vitro, Ex Vivo, and In Vivo Effect of Edible Oils: A Review on Cell Interactions

Consumption of edible oils is a significant part of the dietary pattern in the developed and developing world. Marine and vegetable oils are assumed to be part of a healthy food pattern, especially if one takes into account their potential role in protecting against inflammation, cardiovascular disease, and metabolic syndrome due to the presence of polyunsaturated fatty acids and minor bioactive compounds. Exploring the potential effect of edible fats and oils on health and chronic diseases is an emerging field worldwide. This study reviews the current knowledge of the in vitro, ex vivo, and in vivo effect of edible oils in contact with various cell types and aims to demonstrate which nutritional and bioactive components of a variety of edible oils present biocompatibility, antimicrobial properties, antitumor activity, anti-angiogenic activity, and antioxidant activity. Through this review, a wide variety of cell interactions with edible oils and their potential to counteract oxidative stress in pathological conditions are presented as well. Moreover, the gaps in current knowledge are also highlighted, and future perspectives on edible oils and their health benefits and potential to counteract a wide variety of diseases through possible molecular mechanisms are also discussed.

GC-MS Profiling and Biomedical Applications of Essential Oil of Euphorbia larica Boiss.: A New Report

The present study explored Euphorbia larica essential oil (ELEO) constituents for the first time, obtained via hydro-distillation by means of Gas Chromatography-Mass Spectrometry (GC-MS) profiling. The essential oil was screened in vitro against breast cancer cells, normal cell lines, α-glucosidase, carbonic anhydrase-II (CA-II), free radical scavenging and in vivo analgesic and anti-inflammatory capabilities. The GC-MS screening revealed that the ELEO comprises sixty compounds (95.25%) with the dominant constituents being camphene (16.41%), thunbergol (15.33%), limonene (4.29%), eremophilene (3.77%), and β-eudesmol (3.51%). A promising antidiabetic capacity was noticed with an IC50 of 9.63 ± 0.22 μg/mL by the ELEO as equated to acarbose with an IC50 = 377.71 ± 1.34 μg/mL, while a 162.82 ± 1.24 μg/mL inhibition was observed against CA-II. Regarding breast cancer, the ELEO offered considerable cytotoxic capabilities against the triple-negative breast cancer (MDA-MB-231) cell lines, having an IC50 = 183.8 ± 1.6 μg/mL. Furthermore, the ELEO was also tested with the human breast epithelial (MCF-10A) cell line, and the findings also presumed that the ELEO did not produce any damage to the tested normal cell lines. The ELEO was effective against the Gram-positive bacteria and offered a 19.8 ± 0.02 mm zone of inhibition (ZOI) against B. atrophaeus. At the same time, the maximum resistance with 18.03 ± 0.01 mm ZOI against the fungal strain Aspergillus parasiticus was observed among the tested fungal strains. An appreciable free radical significance was observed via the DPPH assay with an IC50 = 133.53 ± 0.19 µg/mL as equated to the ABTS assay having an IC50 = 154.93 ± 0.17 µg/mL. The ELEO also offered a substantial analgesic capacity and produced 58.33% inhibition in comparison with aspirin, a 68.47% decrease in writhes, and an anti-inflammatory capability of 65.54% inhibition, as equated to the standard diclofenac sodium having 73.64% inhibition. Hence, it was concluded that the ELEO might be a natural source for the treatment of diabetes mellitus, breast cancer, analgesic, inflammatory, and antimicrobial-related diseases. Moreover, additional phytochemical and pharmacological studies are needed to isolate responsible chemical ingredients to formulate new drugs for the examined activities.

Medicinal and therapeutic properties of garlic, garlic essential oil, and garlic-based snack food: An updated review

Garlic (Allium sativum) is an edible tuber belonging to the family Liliaceae. It has been used since ancient times as a spice to enhance the sensory characteristics of food and as a household remedy for the treatment of a variety of ailments. Garlic has been studied for its medicinal and therapeutic effects in the treatment of various human diseases for a long time. Health benefits associated with the consumption of garlic are attributed to the various sulfur compounds present in it such as allicin, ajoene, vinyl-dithiin, and other volatile organosulfur compounds which are all metabolized from alliin. Several researches in the literature have shown evidence that garlic exhibits antioxidant, antiviral, anti-microbial, anti-fungal, antihypertensive, anti-anemic, anti-hyperlipidemic, anticarcinogenic, antiaggregant, and immunomodulatory properties. The present review identifies and discusses the various health benefits associated with the consumption of garlic, its essential oil, and bioactive constituents, along with exploring the various snack-food products developed by incorporating garlic.

A Status Review on Health-Promoting Properties and Global Regulation of Essential Oils

Since ancient times, essential oils (EOs) have been known for their therapeutic potential against many health issues. Recent studies suggest that EOs may contribute to the regulation and modulation of various biomarkers and cellular pathways responsible for metabolic health as well as the development of many diseases, including cancer, obesity, diabetes, cardiovascular diseases, and bacterial infections. During metabolic dysfunction and even infections, the immune system becomes compromised and releases pro-inflammatory cytokines that lead to serious health consequences. The bioactive compounds present in EOs (especially terpenoids and phenylpropanoids) with different chemical compositions from fruits, vegetables, and medicinal plants confer protection against these metabolic and infectious diseases through anti-inflammatory, antioxidant, anti-cancer, and anti-microbial properties. In this review, we have highlighted some targeted physiological and cellular actions through which EOs may exhibit anti-inflammatory, anti-cancer, and anti-microbial properties. In addition, it has been observed that EOs from specific plant sources may play a significant role in the prevention of obesity, diabetes, hypertension, dyslipidemia, microbial infections, and increasing breast milk production, along with improvements in heart, liver, and brain health. The current status of the bioactive activities of EOs and their therapeutic effects are covered in this review. However, with respect to the health benefits of EOs, it is very important to regulate the dose and usage of EOs to reduce their adverse health effects. Therefore, we specified that some countries have their own regulatory bodies while others follow WHO and FAO standards and legislation for the use of EOs.

In Vitro Evaluation of Antiprotozoal Properties, Cytotoxicity Effect and Anticancer Activity of New Essential-Oil Based Phytoncide Mixtures

Protozoa, in both humans and animals, are one of the leading causes of disease. International programmes introduced in many countries have helped reduce the incidence of disease. However, it has recently become increasingly difficult to achieve the goals set for the coming years. One of the main reasons for this, as with other pathogenic organisms, such as bacteria and fungi, is the increasing resistance to current methods of treating and preventing infection. Therefore, new therapies with high efficacy are needed. In the present study, the novel mixtures of essential oils (EOs), clove, garlic, Ceylon cinnamon, and rosemary with organic acids (acetic, propionic, lactic) and metal ions (Cu, Mn, Zn) were tested against five selected model protozoa (Euglena gracilis, Gregarina blattarum, Amoeba proteus, Paramecium caudatum, Pentatrichomonas hominis). The cytotoxicity and potential anticancer activity of the obtained combinations were tested on the human fibroblasts (NHDF) and human cancer cell lines (A549, MCF7, LoVo, HT29). All of the mixtures showed very good antiprotozoal properties. The most efficient were the combination of clove and rosemary essential oils, mixtures of acids, and Mn ions. The LD₅₀ values were in the range of 0.001-0.006% and the LD₁₀₀ values were 0.002-0.008%. All of the tested mixtures did not show cytotoxicity against normal cells, but did show growth inhibition against cancer cell lines. The most cytotoxic against cancer cells were combinations with cinnamon essential oil. Nevertheless, the proposed combinations containing essential oils, organic acids, and metal ions have high antiprotozoal activity, with low toxicity to healthy human cells.

trans-Cinnamaldehyde as a Novel Candidate to Overcome Bacterial Resistance: An Overview of In Vitro Studies

The increasing of drug-resistant bacteria and the scanty availability of novel effective antibacterial agents represent alarming problems of the modern society, which stimulated researchers to investigate novel strategies to replace or assist synthetic antibiotics. A great deal of attention has been devoted over the years to essential oils that contain mixtures of volatile compounds and have been traditionally exploited as antimicrobial remedies. Among the essential oil phytochemicals, remarkable antimicrobial and antibiotic-potentiating activities have been highlighted for cinnamaldehyde, an α,β-unsaturated aldehyde, particularly abundant in the essential oils of Cinnamomum spp., and widely used as a food additive in industrial products. In line with this evidence, in the present study, an overview of the available literature has been carried out in order to define the bacterial sensitizing profile of cinnamaldehyde. In vitro studies displayed the ability of the substance to resensitize microbial strains to drugs and increase the efficacy of different antibiotics, especially cefotaxime, ciprofloxacin, and gentamicin; however, in vivo, and clinical trials are lacking. Based on the collected findings, cinnamaldehyde appears to be of interest as an adjuvant agent to overcome superbug infections and antibiotic resistance; however, future more in-dept studies and clinical investigations should be encouraged to clarify its efficacy and the mechanisms involved.

Characterization and Biological Studies of Synthesized Titanium Dioxide Nanoparticles from Leaf Extract of Juniperus phoenicea (L.) Growing in Taif Region, Saudi Arabia

Green synthesis of metal nanoparticles in nanosized form has acquired great interest in the area of nanomedicine as an environmentally friendly and cost-effective alternative compared to other chemical and physical methods. This study deals with the eco-friendly green synthesis of titanium dioxide nanoparticles (TiO2 NPs) utilizing Juniperus phoenicea leaf extract and their characterization. The biosynthesis of TiO2 NPs was completed in 3 h and confirmed by UV-Vis spectroscopy, a strong band at 205.4 nm distinctly revealed the formation of NPs. Transmissions electron microscopy (TEM) analysis showed the synthesized TiO2 NPs are spherical in shape, with a diameter in a range of 10–30 nm. The XRD major peak at 27.1° congruent with the (110) lattice plane of tetragonal rutile TiO2 phase. Dynamic light scattering (DLS) analysis revealed synthesized TiO2 NPs average particle size (hydrodynamic diameter) of (74.8 ± 0.649) nm. Fourier transmission infrared (FTIR) revealed the bioactive components present in the leaf extract, which act as reducing and capping agents. The antimicrobial efficacy of synthesized TiO2NPs against, Staphylococcus aureus, and Bacillus subtilis (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), Yeast strain (Saccharomyces cerevisiae) and fungi (Aspergillus niger, and Penicillium digitatum) assayed by a disc diffusion method. TiO2NPs inhibited all tested strains by mean inhibition zone (MIZ), which ranged from the lowest 15.7 ± 0.45 mm against K. pneumoniae to the highest 30.3 ± 0.25 against Aspergillus niger. The lowest minimum inhibitory concentration (MIC) and bactericidal (MBC) values were 20 μL/mL and 40 μL/mL of TiO2NPs were observed against Asp. niger. Moreover, it showed significant inhibitory activity against human ovarian adenocarcinoma cells with IC50 = 50.13 ± 1.65 µg/mL. The findings concluded that biosynthesized TiO2 NPs using Juniperus phoenicea leaf extract can be used in medicine as curative agents according to their in vitro antibacterial, antifungal, and cytotoxic activities.

Screening of Rosemary Essential Oils with Different Phytochemicals for Antioxidant Capacity, Keratinocyte Cytotoxicity, and Anti-Proliferative Activity

Nowadays, the demand for rosemary essential oils (REOs) in the cosmetic, food, and pharmaceutical industries is increasing, and the abundant germplasm resources of rosemary provide more possibilities for functional applications. The REOs from six cultivars were selected to evaluate and compare their bioactivities. REOs have good cellular antioxidant activity in scavenging reactive oxygen species, and the technology for order preference by similarity to an ideal solution (TOPSIS)-random forest multivariate model indicated that 'Dutch Mill' REO has the best antioxidant activity, which is closely related to its verbenone content. In addition, α-pinene-dominant REOs are more toxic to human keratinocytes, which is closely related to the content of α-pinene, as revealed by multivariate analyses. Moreover, anti-proliferative assays on six cancer cell lines showed that all REOs have a higher anti-proliferative ability against human pancreatic cancer cell line SW1990 and gastric epithelial cell line NCI-N87. Among them, 'Miss Jessopp's Upright' and 'Blue Lagoon' REOs exhibit more prominent anti-proliferative activity. Our study provides a reference value for exploring the application potential of different REOs by evaluating their differences in chemical composition and bioactivity.

Immune Defences: A View from the Side of the Essential Oils

The use of essential oils is increasingly being investigated among new therapeutic approaches based on medicinal plants and their extracts. With the wide use of synthetic and semi-synthetic antimicrobial drugs, the spread of drug-resistant clinical isolates has increased, and research is directed towards natural products, such as essential oils, as useful antimicrobial resources. In the context of a prospective infection, we compared the impact of essential oils and common antimicrobial agents on the microbicidal activity of human phagocytes. Here, we present the results of our decades-long investigation into the effectiveness of thyme red oil (26.52% thymol chemotype), tea tree oil (TTO), and Mentha of Pancalieri [(Mentha x piperita (Huds) var. officinalis (Sole), form rubescens (Camus) (Lamiaceae)] essential oils on human polymorphonuclear leukocytes (PMNs) capacity to kill clinical strains of Candida albicans and C. krusei when compared to three antifungal drugs used to treat candidiasis (fluconazole, anidulafungin, and caspofungin) These essential oils demonstrate antifungal drug-like and/or superior efficacy in enhancing intracellular killing by PMNs, even at subinhibitory concentrations. Our results are compared with data in the literature on essential oils and immune system interactions. This comparison would aid in identifying therapeutic solutions to the increasingly prevalent antibiotic resistance as well as filling in any remaining knowledge gaps on the bioactivity of essential oils.

Substantivity of mouth-rinse formulations containing cetylpyridinium chloride and O-cymen-5-ol: a randomized-crossover trial

BACKGROUND

The efficacy of mouth-rinses strongly depends upon their substantivity. The use of natural and non-toxic products that avoid secondary effects is gaining interest in preventive dentistry. The purpose of this study was to evaluate the substantivity of two formulations of mouth-washing solutions based on cetylpyridinium (CPC) and O-cymen-5-ol.

METHODS

This was a randomized, double-blind, crossover trial conducted at the Faculty of Medicine and Health Sciences of the University of Barcelona. Bacterial re-colonization was followed by live/dead (SYTO^TM9 + propidium iodide) bacterial staining and measured by confocal laser scanning microscopy and fluorometry. Unstimulated saliva samples were collected from 16 healthy individuals at baseline saliva and then, at 15 min, 30 min and 1, 2, 3, and 4 h after the following mouth-rinses: (i) a single, 1-min mouth-rinse with 15 ml of placebo (negative control); (ii) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) ; (iii) a single, 1-min mouth-rinse with 15 ml of O-cymen-5-ol (0.09%); (iv) a single, 1-min mouth-rinse with 15 ml of CPC (0.05%) + O-cymen-5-ol (0.09%).

RESULTS

Proportion of dead bacteria was significantly higher for all mouthrinses during the first 15 min compared to baseline (CPC = 48.0 ± 13.9; 95% CI 40.98-56.99; p < 0.001, O-cymen-5-ol = 79.8 ± 21.0; 95% CI 67.71-91.90; p < 0.05, CPC + O-cymen-5-ol = 49.4 ± 14; 95% CI 40.98-56.99; p < 0.001 by fluorometry and 54.8 ± 23.0; 95% CI 41.50-68.06; p < 0.001, 76.3 ± 17.1; 95% CI 66.36-86.14; p < 0.001, 47.4 ± 11.9; 95% CI 40.49-54.30; p < 0.001 by confocal laser scanning microscopy, respectively). Nevertheless, after 4 h, CPC + O-cymen-5-ol was the only one that obtained significant values as measured by the two quantification methods used (80.3 ± 22.8; 95% CI 67.15-93.50; p < 0.05 and 81.4 ± 13.8; 95% CI 73.45-89.43; p < 0.05). The combined use of CPC + O-cymen-5-ol increased the substantivity of the mouthrinse with respect to mouthrinses prepared with either of the two active products alone.

CONCLUSION

The synergistic interaction of CPC and O-cymen-5-ol prolongs their substantivity. The resulting formulation may be as effective as other antimicrobials, such as triclosan or chlorhexidine, but without their undesirable secondary effects. Thus, mouthrinsing products based on Combinations of CPC and O-cymen-5-ol may replace in the near future Triclosan and Chlorhexidine-based mouthrinses.

In Vitro and In Silico Pharmacological and Cosmeceutical Potential of Ten Essential Oils from Aromatic Medicinal Plants from the Mascarene Islands

In this study, 10 essential oils (EOs), from nine plants (Cinnamomum camphora, Curcuma longa, Citrus aurantium, Morinda citrifolia, Petroselinum crispum, Plectranthus amboinicus, Pittosporum senacia, Syzygium coriaceum, and Syzygium samarangense) were assessed for their antimicrobial, antiaging and antiproliferative properties. While only S. coriaceum, P. amboinicus (MIC: 0.50 mg/mL) and M. citrifolia (MIC: 2 mg/mL) EOs showed activity against Cutibacterium acnes, all EOs except S. samarangense EO demonstrated activity against Mycobacterium smegmatis (MIC: 0.125-0.50 mg/mL). The EOs were either fungistatic or fungicidal against one or both tested Candida species with minimum inhibitory/fungicidal concentrations of 0.016-32 mg/mL. The EOs also inhibited one or both key enzymes involved in skin aging, elastase and collagenase (IC₅₀: 89.22-459.2 µg/mL; 0.17-0.18 mg/mL, respectively). Turmerone, previously identified in the C. longa EO, showed the highest binding affinity with the enzymes (binding energy: -5.11 and -6.64 kcal/mol). Only C. aurantium leaf, C. longa, P. amboinicus, P. senacia, S. coriaceum, and S. samarangense EOs were cytotoxic to the human malignant melanoma cells, UCT-MEL1 (IC₅₀: 88.91-277.25 µg/mL). All the EOs, except M. citrifolia EO, were also cytotoxic to the human keratinocytes non-tumorigenic cells, HaCat (IC₅₀: 33.73-250.90 µg/mL). Altogether, some interesting therapeutic properties of the EOs of pharmacological/cosmeceutical interests were observed, which warrants further investigations.

Neutrophil Immunomodulatory Activity of Nerolidol, a Major Component of Essential Oils from Populus balsamifera Buds and Propolis

Propolis is a resinous mixture of substances collected and processed from various botanical sources by honeybees. Black poplar (Populus balsamifera L.) buds are one of the primary sources of propolis. Despite their reported therapeutic properties, little is known about the innate immunomodulatory activity of essential oils from P. balsamifera and propolis. In the present studies, essential oils were isolated from the buds of P. balsamifera and propolis collected in Montana. The main components of the essential oil from P. balsamifera were E-nerolidol (64.0%), 1,8-cineole (10.8%), benzyl benzoate (3.7%), α-terpinyl acetate (2.7%), α-pinene (1.8%), o-methyl anisol (1.8%), salicylaldehyde (1.8%), and benzyl salicylate (1.6%). Likewise, the essential oil from propolis was enriched with E-nerolidol (14.4%), cabreuva oxide-VI (7.9%), α-bisabolol (7.1%), benzyl benzoate (6.1%), β-eudesmol (3.6%), T-cadinol (3.1%), 2-methyl-3-buten-2-ol (3.1%), α-eudesmol (3.0%), fokienol (2.2%), nerolidol oxide derivative (1.9%), decanal (1.8%), 3-butenyl benzene (1.5%), 1,4-dihydronaphthalene (1.5%), selina-4,11-diene (1.5%), α-cadinol (1.5%), linalool (1.4%), γ-cadinene (1.4%), 2-phenylethyl-2-methyl butyrate (1.4%), 2-methyl-2-butenol (1.3%), octanal (1.1%), benzylacetone (1.1%), and eremoligenol (1.1%). A comparison between P. balsamifera and propolis essential oils demonstrated that 22 compounds were found in both essential oil samples. Both were enriched in E-nerolidol and its derivatives, including cabreuva oxide VI and nerolidol oxides. P. balsamifera and propolis essential oils and pure nerolidol activated Ca²⁺ influx in human neutrophils. Since these treatments activated neutrophils, the essential oil samples were also evaluated for their ability to down-regulate the neutrophil responses to subsequent agonist activation. Indeed, treatment with P. balsamifera and propolis essential oils inhibited subsequent activation of these cells by the N-formyl peptide receptor 1 (FPR1) agonist fMLF and the FPR2 agonist WKYMVM. Likewise, nerolidol inhibited human neutrophil activation induced by fMLF (IC₅₀ = 4.0 μM) and WKYMVM (IC₅₀ = 3.7 μM). Pretreatment with the essential oils and nerolidol also inhibited human neutrophil chemotaxis induced by fMLF, again suggesting that these treatments down-regulated human neutrophil responses to inflammatory chemoattractants. Finally, reverse pharmacophore mapping predicted several potential kinase targets for nerolidol. Thus, our studies have identified nerolidol as a potential anti-inflammatory modulator of human neutrophils.

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.

Plant Nanovesicles for Essential Oil Delivery

Essential oils' therapeutic potential is highly recognized, with many applications rising due to reported anti-inflammatory, cardioprotective, neuroprotective, anti-aging, and anti-cancer effects. Nevertheless, clinical translation still remains a challenge, mainly due to essential oils' volatility and low water solubility and stability. The present review gathers relevant information and postulates on the potential application of plant nanovesicles to effectively deliver essential oils to target organs. Indeed, plant nanovesicles are emerging as alternatives to mammalian vesicles and synthetic carriers due to their safety, stability, non-toxicity, and low immunogenicity. Moreover, they can be produced on a large scale from various plant parts, enabling an easier, more rapid, and less costly industrial application that could add value to waste products and boost the circular economy. Importantly, the use of plant nanovesicles as delivery platforms could increase essential oils' bioavailability and improve chemical stability while reducing volatility and toxicity issues. Additionally, using targeting strategies, essential oils' selectivity, drug delivery, and efficacy could be improved, ultimately leading to dose reduction and patient compliance. Bearing this in mind, information on current pharmaceutical technologies available to enable distinct routes of administration of loaded vesicles is also discussed.

First Report on Comparative Essential Oil Profile of Stem and Leaves of Blepharispermum hirtum Oliver and Their Antidiabetic and Anticancer Effects

The current research was designed to explore the Blepharispermum hirtum Oliver (Asteraceae) stem and leaves essential oil (EO) composition extracted through hydro-distillation using gas chromatography-mass spectrometry (GC-MS) analysis for the first time. The EOs of the stem and leaves of B. hirtum were comparatively studied for the in vitro antidiabetic and anticancer potential using in vitro α-glucosidase and an MTT inhibition assay, respectively. In both of the tested samples, the same number of fifty-eight compounds were identified and contributed 93.88% and 89.07% of the total oil composition in the EOs of the stem and leaves of B. hirtum correspondingly. However, camphene was observed as a major compound (23.63%) in the stem EO, followed by β-selinene (5.33%) and β-elemene (4.66%) and laevo-β-pinene (4.38%). While in the EO of the leaves, the dominant compound was found to be 24-norursa-3,12-diene (9.08%), followed by β-eudesmol (7.81%), β-selinene (7.26%), thunbergol (5.84%), and caryophyllene oxide (5.62%). Significant antidiabetic potential was observed with an IC50 of 2.10 ± 0.57 µg/mL by the stem compared to the EO of the leaves of B. hirtum, having an IC50 of 4.30 ± 1.56 µg/mL when equated with acarbose (IC50 = 377.71 ± 1.34 µg/mL). Furthermore, the EOs offered considerable cytotoxic capabilities for MDA-MB-231. However, the EO of the leaves presented an IC50 = 88.4 ± 0.5 μg/mL compared to the EO of the stem of B. hirtum against the triple-negative breast cancer (MDA-MB-231) cell lines with an IC50 = 123.6 ± 0.8 μg/mL. However, the EOs were also treated with the human breast epithelial (MCF-10A) cell line, and from the results, it has been concluded that these oils did not produce much harm to the normal cell lines. Hence, the present research proved that the EOs of B. hirtum might be used to cure diabetes mellitus and human breast cancer. Moreover, further studies are considered to be necessary to isolate the responsible bioactive constituents to devise drugs for the observed activities.

Chemical and Antimicrobial Characterization of Mentha piperita L. and Rosmarinus officinalis L. Essential Oils and In Vitro Potential Cytotoxic Effect in Human Colorectal Carcinoma Cells

Colorectal cancer is one of the most frequently diagnosed forms of cancer, and the therapeutic solutions are frequently aggressive requiring improvements. Essential oils (EOs) are secondary metabolites of aromatic plants with important pharmacological properties that proved to be beneficial in multiple pathologies including cancer. Mentha piperita L. (M_EO) and Rosmarinus officinalis L. (R_EO) essential oils are well-known for their biological effects (antimicrobial, antioxidant, anti-inflammatory and cytotoxic in different cancer cells), but their potential as complementary treatment in colorectal cancer is underexplored. The aim of the present study was to investigate the M_EO and R_EO in terms of chemical composition, antioxidant, antimicrobial, and cytotoxic effects in a colorectal cancer cell line—HCT 116. The gas-chromatographic analysis revealed menthone and menthol, and eucalyptol, α-pinene and L-camphor as major compounds in M_EO and R_EO respectively. M_EO exhibited potent antimicrobial activity, moderate antioxidant activity and a low cytotoxic effect in HCT 116 cells. R_EO presented a significant cytotoxicity in colorectal cancer cells and a low antimicrobial effect. The cytotoxic effect on non-cancerous cell line HaCaT was not significant for both essential oils. These results may provide an experimental basis for further research concerning the potential use of M_EO and R_EO for anticancer treatment.

Nanomedicine as an Emerging Technology to Foster Application of Essential Oils to Fight Cancer

Natural prodrugs extracted from plants are increasingly used in many sectors, including the pharmaceutical, cosmetic, and food industries. Among these prodrugs, essential oils (EOs) are of particular importance. These biologically active volatile oily liquids are produced by medicinal and aromatic plants and characterized by a distinctive odor. EOs possess high anticancer, antibacterial, antiviral, and antioxidant potential but often are associated with low stability; high volatility; and a high risk of deterioration with exposure to heat, humidity, light, or oxygen. Furthermore, their bioavailability is limited because they are not soluble in water, and enhancements are needed to increase their potential to target specific cells or tissues, as well as for controlled release. Nanomedicine, the application of nanotechnology in medicine, may offer efficient solutions to these problems. The technology is based on creating nanostructures in which the natural prodrug is connected to or encapsulated in nanoparticles or submicron-sized capsules that ensure their solubility in water and their targeting properties, as well as controlled delivery. The potential of EOs as anticancer prodrugs is considerable but not fully exploited. This review focusses on the recent progress towards the practical application of EOs in cancer therapy based on nanotechnology applications.

Heracleum persicum Essential Oil Nanoemulsion: A Nanocarrier System for the Delivery of Promising Anticancer and Antioxidant Bioactive Agents

Essential oils are important compounds for the prevention and/or treatment of various diseases in which solubility and bio-accessibility can be improved by nanoemulsion systems. Heracleum persicum oil nanoemulsion (HAE-NE) was prepared and biological properties were investigated against human breast cancer cells and normal human fibroblasts foreskin. Particle size, zeta potential and poly dispersity index were 153 nm, −47.9 mV and 0.35, respectively. (E)anethole (57.9%), terpinolene (13.8%), ɣ-terpinene (8.1%), myrcene (6.8%), hexyl butyrate (5.2%), octyl butanoate (4.5%) and octyl acetate (3.7%) was detected in nanoemulsion. Proliferation of cancer cells at IC50 = 2.32 μg/mL was significantly (p < 0.05) inhibited, and cell migration occurred at 1.5 μL/mL. The HAE-NE at 1.5, 2.5 and 3.5 µg/concentration up-regulated caspase 3 and enhanced sub-G1 peak of cell cycle with nil cytotoxic effects in the liver, kidney and jejunum of mice. Villus height, villus width, crypt depth and goblet cells in mice group fed with 10 and 20 mg/kg body weight of HAE-NE improved. Cellular redox state in the liver indicated 10 and 20 mg/kg body weight of nanoemulsion significantly up-regulated the expression of SOD, CAT and GPx genes. Heracleum persicum oil nanoemulsion could be an eco-friendly nanotherapeutic option for pharmaceutical, cosmetological and food applications.

The Effectiveness of Neroli Essential Oil in Relieving Anxiety and Perceived Pain in Women during Labor: A Randomized Controlled Trial

Childbirth is a stressful and physically painful event in a woman’s life and aromatherapy is one of the most used non-pharmacological methods that is effective in reducing anxiety and perceived pain. This randomized controlled study aimed at determining the effect of neroli oil aromatherapy on anxiety and pain intensity perception in 88 women during labor, randomly assigned to either an intervention group (n = 44) or control group (n = 44). Anxiety and perceived pain were assessed through the visual analogue scale during the latent, early, and late active phases of labor. Data analyses included the t-test, Chi-square test, and repeated measures ANOVA. Perceived pain and anxiety in the group receiving aromatherapy were significantly lower than in the control group at all stages of labor (p < 0.05). Specifically, as the labor progressed, pain and anxiety increased in all participants, but the increase was milder in the experimental group than in the control group. The multiparas showed higher average anxiety scores, but not perceived pain, than the primiparas in all phases of labor (p < 0.05). Ultimately, neroli oil aromatherapy during labor can be used as an alternative tool to relieve anxiety and perceived pain in women during all stages of labor.