Frankincense Essential Oil Research Articles

Anti-wrinkle properties of rosehip oil, aloe vera, green tea extract, and frankincense essential oil: Brief review and a survey

The knowledge and opinions of first-year pharmacy students were evaluated after conducting a survey. The survey included 5 knowledge-based and 5 opinion-based questions, focusing on four herbal remedies. The data collected from 28 participants were analyzed for correctness of answers and agreement or disagreement to opinion lead statements. The knowledge-based questions showed an average 74.5% correct answer rate, with the question on Rosehip Oil receiving the highest (about 93%) followed by the Green Tea Extract at 89.3%. Opinion-based questions revealed a positive attitude towards herbal remedies, with over 82% strongly agreeing or somewhat agreeing with their potential benefits. Over 92% of the respondents believed Green Tea Extract and Frankincense Essential Oil possess skin-protecting qualities. Participants had positive attitude towards herbal remedies for skincare. Knowledge-based questions had a satisfactory correct answer rate, and participants largely agreed (82.7%) on the potential of these herbal remedies to enhance skin health and reduce signs of aging. Disagreement was minimal, ranging from 0% to 17.2%, indicating a widespread inclination towards positive agreement. The survey results provide a valuable insight into the potential of herbal remedies in skincare. The knowledge level was satisfactory at 74.5%. Opinions towards Rosehip Oil, Aloe Vera, Green Tea Extract, and Frankincense Essential Oil were largely positive among the surveyed pharmacy students. Limitations of the survey include the small sample size and lack of diversity in the survey participants. Future research should address these limitations and explore additional factors influencing knowledge and opinions regarding herbal remedies for skincare.

Targeted delivery of genistein for pancreatic cancer treatment using hyaluronic-coated cubosomes bioactivated with frankincense oil

Pancreatic cancer is an aggressive malignancy that remains a major cause of cancer-related deaths. Research for innovative anticancer therapeutic options is thus imperative. In this regard, phytotherapeutics offer great promise as efficient treatment modalities, especially leveraging nanodrug delivery. Herein, we innovatively coloaded the flavonoid genistein (Gen) and frankincense essential oil (FO) within cubosomes, which were then coated with the bioactive ligand hyaluronic acid (HA/Gen-FO-Cub) for active-targeting of pancreatic cancer. The novel HA/Gen-FO-Cub displayed optimum nanosize (198.2 ± 4.5 nm), PDI (0.27 ± 0.01), zeta-potential (−34.7 ± 1.2 mV), Gen entrapment (99.3 ± 0.01 %), and controlled Gen release (43.7 ± 1.2 % after 120 h). HA/Gen-FO-Cub exerted selective anticancer activity on pancreatic cancer cells (PANC-1; 8-fold drop in IC50), cellular uptake and anti-migratory effect compared to Gen solution. HA/Gen-FO-Cub revealed prominent cytocompatibility (100 ± 5.9 % viability of human dermal fibroblast). Moreover, HA/Gen-FO-Cub boosted the in vivo anticancer activity of Gen in an orthotopic cancer model, affording tumor growth suppression (2.5-fold drop) and downregulation of NFκB and VEGF (2.9- and 1.8-fold decrease, respectively), compared to Gen suspension. Antimetastatic efficacy and Bcl-2-downexpression was histologically confirmed. Our findings demonstrate the promising anticancer aptitude of HA/Gen-FO-Cub as an effective phytotherapeutic nanodelivery system for pancreatic cancer therapy.

Basis with RNA-Seq and WGCNA to explore the effect of Frankincense essential oil on dextran sodium sulfate-induced ulcerative colitis through MAPK/NF-κB signaling

PurposeFrankincense has been shown in studies to have healing benefits for people with ulcerative colitis (UC). However, its underlying mechanisms have not been fully investigated. The objective of this study was to explore the potential molecular mechanisms of Frankincense essential oil (FREO) in improving dextran sodium sulfate (DSS)-induced UC from multiple perspectives. MethodsThe FREO components were analyzed by GC–MS, and the interactions between the key active components and the mechanism of FREO were determined based on RNA-seq, “quantity-effect” weighting coefficient network pharmacology, WGCNA and pharmacodynamic experiments. The protection of FREO against DSS-induced UC mice was assessed by behavioral and pathological changes through mice. The expression of pro-inflammatory cytokines was measured using enzyme-linked immunosorbent assay. The expression of MAPK and NF-κB-related proteins by the Western Blotting and immunohistochemistry method. ResultsTreatment with FREO significantly improved the symptoms of weight loss, diarrhea, stool blood, and colon shortening in UC mice. Reduced intestinal mucosal damage and the degree of inflammatory cell infiltration in the colon. Decreased TNF-α and IL-6 levels in mice's serum and inhibited phosphorylation of ERK, p65 in MAPK and NF-κB signaling. ConclusionFREO may decrease the inflammatory response to reduce the symptoms of UC by modulating the MAPK/ NF-κB pathway. This may be due to the synergistic interaction of the effective ingredient Hepten-2-yl tiglate, 6-methyl-5-, Isoneocembrene A and P-Cymene. This study provides a promising drug candidate and a new concept for the treatment of UC.

Unlocking the Anticancer Potential of Frankincense Essential Oils (FEOs) Through Nanotechnology: A Review.

Cancer is a group of heterogeneous diseases that occur when cells in the body proliferate and divide uncontrollably. As the current treatment modalities have pros and cons, the discovery of new chemotherapeutic agents with the least side effects is one of the most investigated research areas. In this context, plant-based natural products are a rich source of drugs and have served humanity for ages. Frankincense essential oils (FEOs) are among the most promising plant-based oils in Gulf countries. In addition to their high cultural value, FEOs are also famous for their engaging biological activities, including anti-cancerous. However, the practical application of FEOs is often hindered/by their low water solubility, limited bioavailability, high volatility, and sensitivity toward heat, humidity, light, or oxygen. Thus, a significant demand for technological advancement would improve their ability to target particular cells and tissues. Nanotechnology emerged as an exciting approach in this context. Through suitable nano-formulation (functionalization or encapsulation into a nanostructure), issues arising due to solubility, targeting capability, and delivery can be controlled.

Chemical Compositions of Essential Oil of Agarwood <i>(Aquilaria crassna)</i> Harvested in Phu Quoc Island, Vietnam

The importance of natural products derived from Agarwood species is increasingly emphasized in the production of perfumery or cosmetic products made on Agarwood species. On the other hand, due to the predominant amount of aromatic compounds in essential oils, frankincense essential oil is increasingly popular with high economic value. Therefore, in this study, we focused on the extraction process of essential oils and evaluated the chemical composition present in the essential oils by the GC-MS method. Differences in the composition of essential oils between natural and artificial agarwood may be due to species, habitat conditions, climate, geographical conditions, and extraction methods in different regions. Specifically, volatile components in essential oils were identified as Neopetasone (14.43%); Dihydroagarofuran-15-al (9.20%); Jinko-cramol (5.02%); Valeriano (4.94%); Agarofuran <b-> (8.02%); Dihydrokaranone (3.25%), Valenca-1 (10), 8-dien-11-ol (5.95%) and Selina-4,11-dien-14-al (2.73%), contribute to determining the main aroma in Agarwood essential oil.

Acute, genetic, and target organ toxicity profiling of Frankincense essential oil from Boswellia sacra in zebrafish (Danio rerio)

Frankincense oil is widely used across the globe for various therapeutic implications. However, the potential toxicity profile of Frankincense oil has not been well explored. The present study is a debut attempt to study the organ-specific (cardiac, hepatic, and neuromuscular) toxicity profile of Frankincense essential oil from Boswellia sacra using the zebrafish embryo model. The results revealed a “no observed effect concentration” (NOEC) dose of Frankincense oil of 300 µg/ml. Signs of cardiac toxicity were not observed if the zebrafish embryos were incubated with Frankincense oil (100 µg/ml). In addition, signs of genotoxicity were also not observed at the same concentration. Similarly, neuromuscular toxicity evaluated by the locomotor activity in the presence of light and hepatic toxicity measured by liver size, yolk retention, and steatosis were not found. Despite the absence of toxic effects of Frankincense oil on zebrafish embryo survival, it should be further investigated to assess if the prolonged administration of Frankincense oil in higher vertebrates might induce potential toxic effects.

Antioxidant, Antimicrobial, and Anti-Insect Properties of Boswellia carterii Essential Oil for Food Preservation Improvement

Boswellia carterii, known as frankincense, is a fragrant medicinal plant. The essential oil from this plant is often used in traditional medicine or aromatherapy. Due to its positive properties, it has potential applications as an antimicrobial agent in medicine and the food industry. The aim of this study was to evaluate the antimicrobial, anti-insect, and antioxidant activities of frankincense essential oil (FEO). The composition of volatile compounds was determined by GC/MS, and the main components were found to be α-pinene (37.0%), α-limonene (19.8%), and p-cymene (6.3%). The antioxidant activity was evaluated with DPPH and ABTS methods with the resulting inhibition of 73.88 ± 0.35% of DPPH radical (6.27 ± 0.17 TEAC) and 97.09 ± 0.48% of ABTS radical cation (5.21 ± 0.07 TEAC). The antimicrobial activity was the strongest against Candida species with inhibition zones in the range of 38.00–44.00 mm and MIC 50 and MIC 90 values of 11.72 and 12.58 μL/mL, respectively. The inhibition activity of the vapor phase was the highest against G+ and G− bacteria growing on a carrot with inhibition ranging from 65.14 to 93.67%. The anti-insect activity against O. lavaterae was determined as 100% at 100% concentration and 50% at 25% concentration. The degradation of biofilm was tested with MALDI-TOF MS, and changes in the protein profile were observed.

Screening of the Acaricidal Activity of Essential Oils against Panonychus citri (McGregor) (Acari: Tetranychidae)

The citrus red mite, Panonychus citri (McGregor), is an important pest of citrus in China, where pesticides are commonly used in citrus orchards. In order to reduce the use of chemical pesticides against P. citri and the development of resistance, the screening of biological control agents has attracted the attention of students. In this study, seven plant essential oils with high toxicity were selected from 40 plant essential oils by the leaf-dip bioassay, including plant essential oils of lemongrass, patchouli, juniper berry, sage, clove, frankincense, and citrus. The LC50 after 72 h treatment were 3.198 μL/mL, 8.312 μL/mL, 3.244 μL/mL, 6.701 μL/mL, 8.350 μL/mL, 21.953 μL/mL, and 8.788 μL/mL, respectively. According to the LT50, the essential oils’ acute toxicity to P. citri from high to low were lemongrass, juniper berry, patchouli, citrus, sage, vetiver, and frankincense essential oils. In general, lemongrass and juniper berry essential oils have the best acaricidal effect and have high application value for the biological control of P. citri, which provides a basis for the development of botanical acaricides.

Omani Frankincense nanoemulsion formulation efficacy and its latent effects on biological aspects of the spiny bollworm Earias insulana (Boisd.).

Our research shed light on the perspective of formulation technology regarding its responsibility to provide phyto-insecticides that are worthy of research into potential novel applications. There has been an increase in interest in using nanoemulsion as a new formulation in a variety of sectors during the last several decades. Boswellia sacra essential oil (Fam: Burseraceae) from the resin of frankincense trees has been recently proposed as a promising ingredient in a new generation of botanical insecticides. Frankincense nanoemulsion was formulated in 5% ratios comprising frankincense oil, surfactants, and water. A frankincense nanoemulsion was prepared using a high-energy ultra-sonication process and characterized by dynamic light scattering transmission electron microscopy surface tension, viscosity, and zeta potential value. Gas chromatography/mass spectrometry (GC/MS) was used to identify the chemical profiles of frankincense essential oil. Furthermore, insecticidal effects against second instar larvae of the spiny bollworm, Earias insulana, as well as their latent effects on the larvae were studied. In the present study, the formulation was a good nanoemulsion. The surface tension was 53.69, the viscosity was 4.76 cPs, the zeta potential was-10 mV, and the size distribution was 41.30 nm. The polydispersity index (PDI) of the nanoemulsion was found to be 0.26, and the morphology of the frankincense nanoemulsion was visualized in a spherical shape. The main constituents identified in frankincense oil were α-pinene (15.52%); monolinolenin (12.92%); and geranylgeranyl acetate (9.99%). The results showed significant insecticidal activity against the larval stage and considerably decreased the pupation percentage with increasing the volume of the frankincense nanoemulsion. On the other hand, the latent effects of the frankincense nanoemulsion on E. insulana resulted in a higher prolongation of larval and pupal durations as well as a significant reduction in the weight of larvae and pupae of E. insulana. Additionally, frankincense nanoemulsion dramatically influenced the adult emergence percentage. It also caused a significantly lower hatchability percentage compared to the untreated control. The concentrations used and the types of mating combination have a significant effect on the fecundity of E. insulana. This novel frankincense nanoemulsion formulation could be used in strategies to control the spiny bollworm on cotton plants.

Biochar prepared from Ficus nitida as a carrier for frankincense essential oil (Boswellia sacra) to control some stored product insects

The insecticidal activity of biochar that prepared from Ficus nitida tree residues at 500 and 700οC °C was evaluated against some stored product insects Tribolium castaneum, Rhyzopertha dominica and Oryzaephilus surinamensis, alone and as a carrier for the frankincense essential oil (Boswellia sacra) after 0, 15 and 30 days storage periods. The results showed the O. surinamensis was the most susceptible and the biochar prepared at 500οC was the most active against all tested insects. Also, the toxicity increased with increasing storage period only against R. dominica. The formula was more toxic than biochar or oil alone, especially against T. castaneum. The elemental analysis showed low carbon and high oxygen contents in the biochar 500 and the FTIR analysis showed a large number of functional groups on biochar 500 compared to biochar 700 which may attribute to the slightly higher toxicity of biochar. SEM images of the ventral surface of treated O. surinamensis showed the adhesion of biochar on all body parts, Moreover, the sensilla within the external surface of the elytra are partly absent. Our results suggest the promising use of biochar against some stored product insects and can be effectively loaded with other safe chemicals, more studies are needed to understand its effects on insects.

Encapsulation of Frankincense Essential Oil by Microfluidic and Bulk Approaches: A Comparative Study

Herbs and hand-made herbal remedies have been long used for disease control, treatment, and health improvement. Evidence suggests that a single herb’s compounds can have synergistic functions with probably no adverse effect. Unfortunately, the traditional administration of essential oil (EO) does not follow a regulatory dose regimen, causing reduced bioavailability due to EO evaporation or denaturation in harsh biological environments. Hence, encapsulation can help enhance EO stability and dose dependence. Here, chitosan nanoparticles (ChNPs) were used to encapsulate frankincense essential oil (FEO) to preserve its remarkable therapeutic effects. Also, traditional bulk preparation methods were compared with microfluidic with central aqueous stream configuration (CAS). The results indicated the higher quality of microfluidic-based nanoparticles with uniform, spherical, and separated morphologies. The size of bulk and microfluidic nanoparticles ranged from 86 to 118 nm, the surface charge varied from 12.5 to 19.5 for different amounts of FEO, and the as-prepared colloid remained stable for three days. Narrow size distribution (PDI≤0.28) and high encapsulation efficiency (EE≤99 %) were achieved using the microfluidic process compared to the bulk method (PDI=0.74, EE≤90 %). The microfluidic nanoparticle also indicated a burst release rate greater than the bulk method (≤30 %). It was concluded that the high-performance microfluidic approach provided higher quality and more control over nanoparticle properties.

Comparison of Volatile Constituents Present in Commercial and Lab-Distilled Frankincense (Boswellia carteri) Essential Oils for Authentication.

A comparative analysis of the chemical constituents present in twenty-one commercial and two lab-distilled frankincense (Boswellia carteri) essential oils was carried out using gas chromatography-mass spectrometry (GC-MS) and chiral gas chromatography-mass spectrometry (CGC-MS) for authentication. Out of the twenty-one commercial samples, six were adulterated with synthetic limonene, three were contaminated with synthetic octyl acetate, three were adulterated with castor oil, and two samples each were contaminated with frankincense resin and Boswellia occulta species, respectively, and one was contaminated with the Boswellia serrata species. Additionally, one sample was contaminated with phthalates as well as a cheap essential oil with similar compositions. Furthermore, one sample was adulterated with copaiba resin and frankincense resin in combination with synthetic octyl acetate. Additionally, one was contaminated with Boswellia serrata species, which was further adulterated with castor oil and frankincense resin. To the best of our knowledge, this is the first report to compare the enantiomeric distribution of chiral terpenoids present in commercial frankincense essential oil with lab-distilled frankincense oil for authentication. The CGC-MS analysis showed the presence of a total of eight chiral terpenoids in lab-distilled frankincense essential oils, which can be used as chemical fingerprints for the authentication of frankincense essential oil.

Frankincense essential oil nanoemulsion specifically induces lung cancer apoptosis and inhibits survival pathways

BackgroundThe volatile fraction of frankincense (Boswellia sacra) oleogum was extracted, formulated in nanoemulsion and tested against lung cancer A549 cell line. First, the gum was hydro-distilled to isolate the volatile fraction (essential oil), which was analyzed via gas chromatography to identify its major volatile constituents. Then, the oil was formulated in two water-based nanoemulsions which differ from one another in the presence of propylene glycol (PG), which is used in the formulation step as a co-surfactant. The pure essential oil as well as its major volatile compound (α-pinene), its two nanoemulsions and a reference drug (Doxorubicin) were evaluated against lung cancer A549 cell lines and WI-38 normal lung cells. The evaluation included cytotoxicity (MTT and IC50), apoptosis (flow cytometric analysis) in addition to genetic assessments for some intrinsic and extrinsic genes relevant to apoptosis and survival pathways.ResultsChromatographic analysis of frankincense essential oil revealed that α-pinene is the major volatile compound which constituent about 60% of that oil. Emulsification of the oil using the low energy technique gave nanoemulsions having major intense particles population (85–90%) with z-average diameter below 20.0 nm. Frankincense oil nanoemulsion fabricated with (PG) showed the best cytotoxic activity toward lung cancer A549 cell compared to PG-free nanoemulsion, α-pinene and the reference drug doxorubicin, along different incubation periods. Flow cytometric analysis also indicated that PG-containing nanoemulsion can induce cancer cells toward apoptosis better than the other formula and the pure oils. The same nanoemulsion was found to upregulate the pro-apoptotic genes [DR5, FAAD, Caspase 8 (Cas8), p53, and Bax] and downregulate the anti-apoptotic and reoccurrence genes (Bcl-2, NF-kB, and STAT-3). Most importantly, the PG-containing nanoemulsion had the least cytotoxic effect on the normal WI-38 lung cells.ConclusionsThese results point out to the potentials of frankincense essential oil (rich in α-pinene) and its PG-nanoemulsion as a promising adjuvant from plant-source to potentiate the activity of the systematic anti-lung cancer drugs.

Gelatin/Persian gum/bacterial nanocellulose composite films containing Frankincense essential oil and Teucrium polium extract as a novel and bactericidal wound dressing

This study aimed to create a new combination for wound dressing with favorable attributes using natural materials. Gelatin films containing Persian gum (Pg), Bacterial nanocellulose (BNc), Frankincense essential oil (FEO), and Teucrium polium extract (TpE) were prepared. The films were studied by Attenuated total reflectance Fourier transform (FTIR-ATR) and SEM. Moreover, mechanical properties, swelling, water desorption, and stability of the films were investigated. In-vitro studies of blood compatibility and also antimicrobial and anti-inflammatory tests were performed for the fabricated films. SEM images proved a uniform dispersion of BNc in the matrix. The incorporation of FEO into the films was shown to make the cavities in the film's micrographs. Moreover, the swelling was found enhanced by Pg and BNc addition to the gelatin film while this index was decreased by FEO addition. Compare to the pure gelatin film, the blended films had more stability with steady degradation under the PBS medium. The biocomposite films showed improved anti-inflammatory and antibacterial activity with Pg, FEO and TpE combination. Blood compatibility studies of the biocomposite films exhibited a non-hemolytic nature. These valuable biological properties of the biocomposite films make them a promising and suitable candidate for wound dressing application.

Potential of frankincense essential oil-loaded whey protein nanoparticles embedded in frankincense resin as a wound healing film based on green technology

The implementation of naturally available curative compounds or the utilization of green biopolymers especially industrial byproducts, are recently applied to develop new topical formulations for treating or managing skin wounds. In this study, frankincense (FRK) essential oil was extracted from Bosolica papyrifera oliogum resin, and encapsulated into whey protein NPs using spray drying technique. A bionanocomposite film was then prepared by embedding FRK essential oil-loaded whey protein NPs into FRK resin using solvent casting technique. Morphological analysis by TEM showed that the prepared NPs were spherical in shape with diameter of about 151 nm and EE % of about 75.9%. The fabricated film showed good tensile strength and improved sustained release of FRK essential oil compared to the oil-loaded whey protein NPs alone. Moreover, it exhibited a significant antimicrobial behavior with very weak hemolytic activity. More importantly, when this film was applied in a full thickness animal wound model, it displayed remarkably improved healing with enhanced collagen deposition associated with decline in the gene expression of interleukin-6 (IL-6) and an increase in the gene expression of transforming growth factor-β1 (TGF- β1) due to the ability of FRK essential oil to modulate inflammation and skin tissue remodeling, suggesting the excellent feasibility of this film as a highly efficient wound dressing film.

The antimicrobial activity of essentials oils of thyme, oregano, copaiba, tea tree, and frankincense against Enterococcus faecallis / Análise da atividade antimicrobiana dos óleos essenciais de tomilho, orégano, copaíba, melaleuca, e olíbano contra Enterococcus faecallis

Oral diseases are among the problems that most affect the quality of life of people in the world. Traditional methods for drug treatment of these diseases are almost always expensive and, in addition, they cause side effects and can promote an increase in bacterial resistance. Thus, the demand for plant-derived products, such as herbal, floral and essential oils, has been growing every day, favoring the development of new therapeutic products that can replace or complement traditional therapeutic treatment. Among the natural products that have been gaining space, essential oils (EOs) stand out. Therefore, the aim of this study was to evaluate the role of thyme, oregano, copaiba, tea tree and frankincense EOs in inhibiting the growth of Enterococcus faecalis bacteria. The oil diffusion technique in agar was performed to evaluate the efficiency of the EOs, at different concentrations: 25%, 50%, 75% and 100%. The EOs that showed the greatest inhibition halo were, in decreasing order: Thyme Oil (5.0 mm), Tea tree Oil (4.70 mm) and Oregano Oil (3.75mm) in the concentration of 100%, with results similar to 0.12% chlorhexidine (positive control), whose inhibition halo was 3 mm. Copaiba and Frankincense oils were not efficient to inhibit bacterial growth at concentrations of 25, 50 and 75%. The results obtained in this research demonstrated that thyme, tea tree and oregano oils inhibited the growth of Enterococcus faecalis bacteria.

Radiation Synthesis of Psyllium/Frankincense Essential Oil –Based Wound Dressing Hydrogels: Antimicrobial, Antioxidant and Wound Healing Performance

Abstract Innovative bioactive hydrogel dressings based on Psyllium (Pys) and Carbopol (Carp) supported with Frankincense essential oil (FO) were fabricated using γ- irradiation facility for crosslinking and sterilization. (Psy-Carp)/FO dressing’s characteristics, hemolytic potential, antioxidant efficiency, antimicrobial activity as well as their morphological features were evaluated. Wound healing efficacy was evaluated using a rat model. The results revealed that the gelation degrees increased by the increase of (Psy) concentration, Carbopol content, and irradiation dose. The incorporation of FO oil up to 5% improves the swelling ability as well as the dressing porosity as shown by SEM images. The incorporation of FO oil enhances the Water Vapor Transmission Rate (WVTR), increases the antioxidant activity. Antimicrobial activity and microbial barrier potency of (Psy-Carp)/FO dressing was tested against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Candida albicans (C. albicans), the results showed that it attenuates microbial growth of all the tested strains after 18 h. by two log cycle and cause a high rate of microbial killing. A significant increase of protein release, decrease in Exopolysaccharides (EPS) content and decrease of membrane surface potential were noticed indicating alternation of cell membrane permeability leading to cell death. In vivo wound healing evaluation using rat model confirms that the tested dressings induce faster wound healing with improvement biochemical parameters compared with that of FO free (Psy-Carp) hydrogel. Based on the above-mentioned results, it can be concluded that (Psy-Carp)/FO hydrogel dressings demonstrate a promising potential as wound care candidates.

Assessment and Characterization of Some New Photosensitizers for Antimicrobial Photodynamic Therapy (aPDT).

The novelty of this study consists on the formulation and evaluation of five complex experimental natural photosensitizers (PS): gel with oregano essential oil (O), gel with methylene blue (AM), gel with a mixture of essential oils (Thieves-H), gel with arnica oil and curcuma extract (CU) and gel with frankincense essential oil (T), used as photosensitizing agents (PS) in antimicrobial photodynamic therapy (aPDT) in the control of microbial biofilm in oral cavity. The experimental PS were characterized by gas chromatography-mass spectrometry (GC-MS), Fourier-transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, cytotoxicity assay, antimicrobial effect and scanning electron microscopy (SEM). The IR spectra of the experimental PS with essential oils exhibit absorption bands due to the presence of water and glycerol in high quantities. The studied compounds had a reduced cytotoxic effect on cell cultures. The lowest cytotoxic effect was observed in experimental PS with oregano essential oil and methylene blue PS. Essential oils with proven antibacterial capabilities used in experimental PS confer antibacterial activity to the gels in which they are incorporated, an activity that may be more efficient use of a PDT therapy. Single bacteria were detected mainly by SEM after 12 h, while aggregate bacteria and micro colonies dominated the samples at 48 h.

Correction: Frankincense essential oil suppresses melanoma cancer through down regulation of Bcl-2/Bax cascade signaling and ameliorates heptotoxicity via phase I and II drug metabolizing enzymes

[This corrects the article DOI: 10.18632/oncotarget.26930.].

In Vitro Antimicrobial Activity of Frankincense Oils from Boswellia sacra Grown in Different Locations of the Dhofar Region (Oman).

Frankincense essential oils from Boswellia sacra have been commonly used to treat microbial infections from as early as the 11th century. The main feature of the plant is its gum resin, from which it is possible to obtain essential oils. In the present study, we focused on the comparative study of the oils extracted from the resins of three different Boswellia sacra cultivars (Najdi, Sahli and Houjri). From each of frankincense resin three successive essential oil samples (Grade 1, Grade 2, Grade 3) were obtained. Houjri gum resin gave the lowest percentage (5%) of total essential oil content but showed the maximum number of volatile components in all three grades. Najdi Grade 2 essential oil showed a minimum inhibitory concentration (MIC) of 52 mg/mL toward relevant pathogens Staphylococcus aureus and Pseudomonas aeruginosa, and samples from Grade 2 of Sahily and Houjiri were particularly active against a dermatological strain Propionibacterium acnes, displaying MIC values of 0.264 and 0.66 mg/mL, respectively. Data obtained from in vitro studies showed that all essential oils had a significant antifungal effect against Candida albicans and Malassezia furfur, showing MIC values ranging from 54.56 to 0.246 mg/mL. This work aims to increase the number of substances available in the fight against pathogens and to combat the phenomenon of antibiotic resistance, encouraging the use of alternative resources, especially in non-clinical settings (farms, food processing, etc.).