Molecular mechanism of the anti-inflammatory effects of plant essential oils: A systematic review

Mechanism analysis of essential oil from Radix Bupleuri for the treatment of asthma through regulation of ectopic olfactory receptor

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Bupleuri is the root of Bupleurum chinense DC. (BC) and a classic aromatic traditional Chinese medicine. The traditional pharmacological effects of Radix Bupleuri are alleviating bronchial spasms, dilating airways, and promoting the resolution of respiratory inflammation, thereby reducing asthma symptoms.

AIM OF THE STUDY

Studies have demonstrated the efficacy of water extracts from BC in asthma treatment. However, the potential role of volatile oil, another active constituent in BC, remains unexplored with asthma. Notably, volatile oil is renowned for its ease of absorption and direct targeting of affected areas, offering distinct advantages in alleviating airway inflammation. This study aims to explain the anti-asthmatic mechanism of BC-oil through in vivo and in vitro pharmacological experiments.

MATERIALS AND METHODS

Firstly, the OVA-induced SD rat asthma model was utilized to evaluate the pharmacological effect of BC-oil by lung function monitoring, HE staining, flow cytometry, ELISA, and RT-qPCR. The anti-asthmatic mechanism was further analyzed by combining transcriptomic analysis of lung tissue from rat model and airway smooth muscle tissue from public database. Initially, GC-MS was used to analyze the components of BC-oil. The anti-asthmatic activity was evaluated in 16-HBE, RBL-2H3, and ASMC cells using CAMKII inhibitors to explore of the critical signal transduction regulated by BC-oil. Furthermore, molecular docking and calcium flow assay were utilized to screen and identify the active components from BC-oil.

RESULTS

Oral administration of BC-oil significantly enhanced pulmonary function in asthmatic SD rats by reducing airway resistance and elastic resistance. Additionally, BC-oil inhibited inflammatory cytokines, including serum IL-2, pulmonary Il1b, Tnf, and Cxcl13, demonstrating potent anti-inflammatory and immunomodulatory effects. In this study, we analyzed the significant role of OR2W3 in asthma using public transcriptomic data. Furthermore, we indicated that BC-oil regulated the expression of Olr1433 and GNAL in rat lung tissue. BC-oil reduced degranulation and inhibited gene expression of Il3 and Tnf in RBL-2H3 cells and suppressed gene expression of IL8 and TNF in 16-HBE cells. BC-oil also attenuated airway smooth muscle cell proliferation and expression of Acta2 and Ccnd1. Furthermore, BC-oil regulates asthma-related cellular processes by activating CAMKII. GC-MS analysis identified 11 components of BC-oil, and n-hexadecanoic acid, linoleic acid and oleic acid from BC-oil were identified to interact with OR2W3 by molecular docking. The calcium flow assay revealed linoleic acid as a significant activator of OR2W3 and indicated that BC-oil alleviated asthma through the ectopic olfactory signaling pathway.

CONCLUSIONS

The mechanism of BC-oil in treating asthma through signal transduction of OR2W3 is revealed at the molecular and cellular levels.

Natural approaches for the management of ulcerative colitis: evidence of preclinical and clinical investigations

Ulcerative colitis (UC) is a recurring autoimmune disorder characterized by persistent inflammation in the mucosal lining of the lower part of the large intestine. Conventional treatment options such as salicylates, corticosteroids, and immunosuppressants often come with severe side effects, limited bioavailability, and the development of drug resistance, which hampers their therapeutic effectiveness. Therefore, it is imperative to explore natural strategies as safe and alternative treatments for UC. Currently, around 40% of UC patients find relief through natural constituents, which can help reduce toxic side effects and maintain clinical remission. This review aims to provide a summary of both preclinical and clinical evidence supporting the efficacy of various natural substances in the prophylaxis of UC. These natural options include plant extracts, essential oils, nutraceuticals, and phytochemicals. Furthermore, we will delve into the potential mechanisms that underlie the protective and curative actions of these novel herbal agents. In summary, this review will explore the effectiveness of natural remedies for UC, shedding light on their preclinical and clinical findings and the mechanisms behind their therapeutic actions. These alternatives offer hope for improved treatment outcomes and reduced side effects for individuals suffering from this challenging autoimmune condition.

Coatings Based on Essential Oils for Combating Antibiotic Resistance

In the current era of widespread antimicrobial resistance, the utilization of essential oils (EOs) derived from plants has emerged as a promising alternative in combating pathogens that have developed resistance to antibiotics. This review explores the therapeutic potential of essential oils as valuable tools in restoring the efficacy of antibiotics, highlighting their unique ability to affect bacteria in multiple ways and target various cellular systems. Despite the challenge of elucidating their precise mode of action, EOs have shown remarkable results in rigorous testing against a diverse range of bacteria. This review explores the multifaceted role of EOs in combating bacterial microorganisms, emphasizing their extraction methods, mechanisms of action, and comparative efficacy against synthetic antibiotics. Key findings underscore the unique strategies EOs deploy to counter bacteria, highlighting significant differences from conventional antibiotics. The review extends to advanced coating solutions for medical devices, exploring the integration of EO formulations into these coatings. Challenges in developing effective EO coatings are addressed, along with various innovative approaches for their implementation. An evaluation of these EO coatings reveals their potential as formidable alternatives to traditional antibacterial agents in medical device applications. This renaissance in exploring natural remedies emphasizes the need to combine traditional wisdom with modern scientific advancements to address the urgent need for effective antimicrobial solutions in the post-antibiotic era.

Chemical composition and the anti-inflammatory effect of volatile compounds from Anaxagorea luzonensis A. Gray

Anaxagorea luzonensis A. Gray, a member of the Annonaceae family, has been used to treat a variety of illnesses for a long time. For the first time, A. luzonensis volatile compounds (ALVCs) were extracted from the leaves, and the components were identified using gas chromatography-mass spectrometry (GC-MS). Further, the main compositions of ALVCs were also assessed for their ability to bind with anti-inflammatory proteins using a docking model. In addition, in vitro tests e.g. inhibition of protein degradation and the inhibition of nitric oxide release using RAW264.7 macrophage cells were utilized for evaluating the anti-inflammatory activity. The results showed that the principal compounds of ALVCs were bulnesol (34.1 %), cubitene (17.8 %), β-eudesmol (10.4 %), epi-longipinanol (5.9 %), and (Z)-nerolidyl acetate (5.5 %). Three compounds viz. bulnesol, cubitene, and β-eudesmol bound firmly to cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), as shown by the in silico analysis, similar to the positive control diclofenac. ALVCs effectively inhibited protein degradation with the IC50 of 31 ± 2.3 μg/mL and inhibited nitric oxide production with the IC50 of 43.30 ± 3.37 μg/mL. These findings showed that ALVCs might have a promising anti-inflammatory effect by blocking several inflammatory proteins.

Anti-inflammatory and/or immunomodulatory activities of Uncaria tomentosa (cat's claw) extracts: A systematic review and meta-analysis of in vivo studies

Background

Uncaria tomentosa (Willd. ex Schult.) DC. (Rubiaceae) is traditionally used by Amazonian indigenous groups to treat inflammatory diseases. To date, there are no systematic reviews and meta-analyses on the use of U. tomentosa for inflammation control in animals supporting the traditional knowledge about this species. This study was conducted to evaluate the effect of U. tomentosa extracts in modulating inflammatory mediators and to determine which types of inflammatory diseases can be treated by this species.

Methods

We conducted a systematic review and meta-analysis of preclinical studies published before 26 July 2023, identified in PubMed, Embase, and Scopus. Four independent reviewers extracted the data and assessed the risks of bias. The effects of U. tomentosa on inflammatory diseases and the inflammatory mediators involved were extracted from the studies. Standardized mean differences (SMD) and 95% confidence intervals (95%CI) of the outcomes were estimated. The meta-analyses were conducted using RevMan 5.4 (Cochrane Collaboration). This protocol was registered in PROSPERO (CRD42023450869).

Results

Twenty-four of 523 studies were included. U. tomentosa extracts decreased the cytokines interleukin (IL)-6 (SMD: -0.72, 95%CI: -1.15, -0.29, p = 0.001) and transcription factor nuclear factor kappa-B (NF-κB) (SMD: -1.19, 95%CI: -1.89, -0.48, p = 0.001). However, the extracts did not significantly alter IL-1 (SMD: -0.16, 95%CI: -0.87, +0.56, p = 0.67), IL-10 (SMD: -0.05, 95%CI:-0.35, 0.45, p = 0.80), or tumor necrosis factor-alpha (TNF-α) levels (SMD: 0.18, 95%CI: -0.25, 0.62, p = 0.41).

Conclusion

Many extracts of stem bark, roots, and leaves of U. tomentosa, mostly aqueous and hydroethanolic, exhibited anti-inflammatory and/or immunomodulatory activities and low toxicity. The extracts decreased NF-κB and IL-6. These findings suggest that this species has the potential to treat inflammatory diseases in which these markers are increased, according to the ethnopharmacological use. These activities are not related to a specific class of compounds.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=450869, Identifier CRD42023450869.

Bioactive Compounds from Medicinal Plants as Potential Adjuvants in the Treatment of Mild Acne Vulgaris

In recent years, there has been a growing interest in the use of medicinal plants and phytochemicals as potential treatments for acne vulgaris. This condition, characterized by chronic inflammation, predominantly affects adolescents and young adults. Conventional treatment typically targets the key factors contributing to its development: the proliferation of Cutibacterium acnes and the associated inflammation. However, these treatments often involve the use of potent drugs. As a result, the exploration of herbal medicine as a complementary approach has emerged as a promising strategy. By harnessing the therapeutic properties of medicinal plants and phytochemicals, it may be possible to address acne vulgaris while minimizing the reliance on strong drugs. This approach not only offers potential benefits for individuals seeking alternative treatments but also underscores the importance of natural remedies of plant origin in dermatological care. The primary aim of this study was to assess the antimicrobial, antioxidant, and anti-inflammatory properties of plants and their phytochemical constituents in the management of mild acne vulgaris. A comprehensive search of scientific databases was conducted from 2018 to September 2023. The findings of this review suggest that medicinal plants and their phytochemical components hold promise as treatments for mild acne vulgaris. However, it is crucial to note that further research employing high-quality evidence and standardized methodologies is essential to substantiate their efficacy and safety profiles.

In Vivo Anti-Inflammatory and Antinociceptive Activities of Black Elder (Sambucus nigra L.) Fruit and Flower Extracts

Sambucus nigra L. (S. nigra, SN) or black elder is a traditional medicinal plant widely used worldwide for therapeutic and dietary purposes. The aim of the current study was to investigate the anti-inflammatory and antinociceptive activities of black elder fruit and flower extracts (SNFrE and SNFlE, respectively). The primary polyphenol constituents in the flower extract were flavonoids and phenolic acids, while anthocyanins were the main components in the fruit extract. SNFrE revealed pronounced and dose-dependent in vivo anti-inflammatory activity assessed by the cotton pellet-induced granuloma test. Doses of 10, 20, and 50 mg/kg BW of SNFrE reduced the weight of induced granuloma in rats by 20.3%, 20.5%, and 28.4%, respectively. At the highest dose (50 mg/kg BW), SNFrE had significant (p < 0.01) anti-inflammatory activity comparable to that of diclofenac, the reference compound used (10 mg/kg BW). In addition, the in vivo antinociceptive activity of the extracts in mice was estimated using the acetic-acid-induced writhing test. Both extracts at doses of 50 mg/kg BW inhibited the abdominal contractions induced by the acetic acid significantly comparing to the control group (p < 0.01). Our findings indicate that black elder extracts and particularly SNFrE possess anti-inflammatory and antinociceptive activities, providing experimental evidence for the use of S. nigra in traditional medicine.

Sesquiterpenoids and hexanorcucurbitacin from Aquilaria malaccensis agarwood with anti-inflammatory effects by inhibiting the STAT1/AKT/MAPK/NLRP3 pathway

Seven unknown compounds 1-7, including four sesquiterpenoids, one azulene-type, one indene-type, and one rare hexanorcucurbitacin, together with eleven knowns ones (8-16), were isolated from the agarwood chips of Aquilaria malaccensis. The structures of the isolated compounds were elucidated by extensive spectroscopic methods such as mass spectrometry, UV, IR, NMR spectroscopy. The precise stereo-chemical configurations of new compounds were determined by calculated ECD spectra data, as well as a single-crystal X-ray diffraction analysis. The isolated compounds 1-7 were evaluated by estimating the levels of nitric oxide (NO), TNF-α, and the expression of enzyme iNOS, and COX-2. Among them, a rare hexanortriterpenoid (7) derived from a cucurbitane-type triterpenoid showed the significantly attenuated neuro-inflammatory effects via the STAT1/AKT/MAPK/NLRP3 signaling pathway on the mechanistic studies.

Exploring the impact of seasonal variations on the chemical composition, antinociceptive, and anti-inflammatory properties of Pogostemon heyneanus Benth. essential oil

Background: Pogostemon heyneanus leaves infusions are relevant in ethnopharmacology for treating colds, coughs, headaches, and asthma. Purpose: The essential oil chemical composition of a Pogostemon heyneanus specimen was monthly monitored from October 2021 to July 2022 to evaluate the climatic influences on its yield and chemical composition and antinociceptive, andanti-inflammatory properties. Methods: The leaves, collected monthly over a 10-month period, were submitted to hydrodistillation. The oils obtained were analyzed by gas chromatography coupled to a mass spectrometer and gas chromatography coupled to flame ionization detector. The P. heyneanus essential oil (PhEO) was tested in vivo to evaluate its peripheral analgesic actions through the abdominal writhing test induced by acetic acid, and peripheral analgesia by tail immersion. Neurogenic and inflammatory pain were evaluated by formalin test, and acute oral toxicity of the oil was also verified. Results: PhEO presented 27 chemical constituents with the highest predominance of patchoulol (43.6%-76.9%), α-bulnesene (0.2%-12.7%), α-guaiene (0.4%-8.9%), seychellene (3.8%-5.1%) and pogostol (0.0%-8.2%). The climatic parameters insolation, humidity, rainfall, and temperature did not influence the essential oil yield or the main chemical constituents, except for pogostol, which presented a strong (r = 0.73) and statistically significant (p < 0.05) correlation with temperature. PhEO did not display toxicity at the maximum 300 mg/kg dosage. The oil showed low peripheral and central analgesic action at 100 mg/kg, while in the neurogenic and inflammatory pain inhibition tests, no actions related to PhEO were observed. In the carrageenan-induced peritonitis test, PhEO did not reduce the migration of leukocytes to the peritoneal cavity compared to the control group. Conclusion: Pogostemon heyneanus is a resistant plant to seasonal influences and a source of patchoulol. Despite ethnopharmacological indications, no in-vivo biological activities such as neurogenic or inflammatory pain were identified in the present work. So, the low influence of the climatic parameters on chemical composition can infer that the low pharmacological activity is also not subject to climatic variations, that is, it does not change due to the climate.

Integrating network pharmacology and experimental verification to decipher the multitarget pharmacological mechanism of Cinnamomum zeylanicum essential oil in treating inflammation

Inflammatory diseases contribute to more than 50 % of global deaths. Research suggests that network pharmacology can reveal the biological mechanisms underlying inflammatory diseases and drug effects at the molecular level. The aim of the study was to clarify the biological mechanism of Cinnamomum zeylanicum essential oil (CZEO) and predict molecular targets of CZEO against inflammation by employing network pharmacology and in vitro assays. First, the genes related to inflammation were identified from the Genecards and Online Mendelian Inheritance in Man (OMIM) databases. The CZEO targets were obtained from the SwissTargetPrediction and Similarity Ensemble Approach (SEA) database. A total of 1057 CZEO and 526 anti-inflammation targets were obtained. The core hub target of CZEO anti-inflammatory was obtained using the protein-protein interaction network. KEGG pathway analysis suggested CZEO to exert anti-inflammatory effect mainly through Tumor necrosis factor, Toll-like receptor and IL-17 signalling pathway. Molecular docking of active ingredients-core targets interactions was modelled using Pyrx software. Docking and simulation studies revealed benzyl benzoate to exhibit good binding affinity towards IL8 protein. MTT assay revealed CZEO to have non-cytotoxic effect on RAW 264.7 cells. CZEO also inhibited the production of NO, PGE2, IL-6, IL-1β and TNF-α and promoted the activity of endogenous antioxidant enzymes in LPS-stimulated RAW 264.7 cells. Additionally, CZEO inhibited intracellular ROS generation, NF-kB nuclear translocation and modulated the expression of downstream genes involved in Toll-like receptor signalling pathway. The results deciphered the mechanism of CZEO in treating inflammation and provided a theoretical basis for its clinical application.

Peppermint as a promising treatment agent in inflammatory conditions: A comprehensive systematic review of literature

Inflammation, a type of the body's defense against injury or infection, causes many chronic disorders including diabetes, cardiovascular disease, and cancer. Therefore, discovering natural compounds with numerous biological activities for the management of inflammation is highly recommended. Out of natural compounds, peppermint and its main component, menthol, has been suggested to possess antiinflammatory potential. Four databases including Web of Sciences, PubMed, Scopus, and Embase were searched to identify articles about peppermint and its antiinflammatory effects up to March 2023. Out of 3805 records screened, 14 articles met the study criteria. The evidence reviewed here proposed peppermint as an antiinflammatory agent. Peppermint may suppress inflammation by activating the AMP-activated protein kinase/unc-51 like kinase 1/nuclear factor-E2 associated factor 2 autophagy pathway, downregulating extracellular signal-regulated kinase-nuclear factor kappa B and mitogen activated protein kinases pathways, attenuating oxidative stress, suppressing the production of pro-inflammatory mediators and nitric oxide, and inducing the production of antiinflammatory prostaglandins. Due to the promising antiinflammatory effects of peppermint and the lack of human studies in this regard, future randomized clinical trials examining the effects of peppermint on inflammation and its related maladies are warranted.

Volatile Oil of Magnolia biondii Pamp. for Transnasal Administration: Its Preparation, Characterization, and Mechanism of Action in the Treatment of Allergic Rhinitis

BACKGROUND

Allergic Rhinitis (AR) is a common chronic nasal condition usually caused by allergens. The immune system overreacts when the body is exposed to allergens, releasing a lot of tissue chemicals that cause congestion, more secretions, and an inflammatory reaction in the nasal mucosa.

METHOD

In clinical practice, it remains a significant public health issue. Modern pharmacological studies have demonstrated that Magnolia Volatile Oil (MVO) has good anti-inflammatory, antibacterial, immunomodulatory, and other pharmacological effects. Previous research and literature reports have reported that MVO has good therapeutic effects on allergic rhinitis. However, due to the poor water solubility of Magnolia, its bioavailability is low. The purpose of this present work is to develop a new microemulsion formulation to improve the stability and bioavailability of MVO.

RESULTS

The droplet size, PDI, and zeta potential of Magnolia volatile oil microemulsion (MVOME) were characterized along with its physical characteristics, and these values were found to be 14.270.03 nm, 0.09410.31, and -0.35850.12 mV, respectively, demonstrating the successful formation of microemulsion. In OVA-induced AR rats, MVO-ME dramatically reduced the serum levels of TNF-α, IL-1β, and IL-6 inflammatory factors. In addition, MVO-ME significantly inhibited the expression of protein levels of PPAR-γ and P65 in the nasal mucosa of AR rats. In this regard, we hypothesized that MVO-ME may play a therapeutic role in AR by activating the PPAR signaling pathway as well as inhibiting the activation of the NF/κB signaling pathway.

CONCLUSION

MVO-ME has systematic advantages, such as high solubility, bioavailability, etc. It is expected to be an efficient nano-drug delivery system for the clinical treatment of allergic rhinitis.

Antiarthritic and Anti-Inflammatory Properties of Cannabis sativa Essential Oil in an Animal Model

Arthritis and inflammatory conditions require effective therapies, but conventional drugs have side effects. This study explored Cannabis sativa L. essential oil (CSEO) as a safer alternative. A chemical characterization of EO conducted via GC/MS showed the presence of sesquiterpene hydrocarbons (67.63%), oxygenated sesquiterpenes (25.91%), and oxygenated monoterpenes (0.99%). The study used three established inflammation induction tests: xylene-induced ear swelling, carrageenan-induced paw inflammation, and inflammation in the paw induced by Freund's complete adjuvant (CFA). Xylene triggered acute inflammation in the ear, while carrageenan-induced acute inflammatory responses through edema and immune-cell recruitment in the paw. CFA-induced arthritis simulated chronic inflammatory conditions. The obtained results demonstrated that treatment with CSEO significantly reduced ear weight in the xylene-induced ear-swelling test, indicating potential inhibition of neutrophil accumulation. In the carrageenan-induced paw inflammation test, CSEO reduced paw volume, suggesting interference with edema formation and leukocyte migration. In the CFA-induced paw inflammation test, CSEO decreased contralateral paw volume, restored body weight, and reduced C-reactive protein levels. Conclusion: this study provides compelling evidence supporting the antiarthritic and anti-inflammatory effects of CSEO. The findings indicate the therapeutic value of EO in the management of arthritis and inflammatory diseases while highlighting the need for further in-depth research to study the molecular mechanisms and validate their safety and efficacy for clinical applications. Preliminary data from this study suggests encouraging prospects for advancing the treatment and prevention of inflammation.

Chemical Composition and Potential Antimicrobial and Anti-Inflammatory Activities of Essential Oil from Fruits of Alpinia zerumbet (Pers.) B.L.Burtt & R.M.Sm

Alpinia zerumbet (Pers.) B.L.Burtt & R.M.Sm. was extensively used in traditional medicine for its several properties, but continuous investigation is needed to discover the properties of its essential oils (EOs). This work evaluated the properties of an EO obtained by steam distillation (named ESD) as well as extracts obtained by petroleum ether (named EP) both from Alpinia zerumbet fruits. Gas chromatography-mass spectrometry (GC-MS) was chosen to identify the composition, and eleven compounds were identified as the main components of the EO and EP of Alpinia zerumbet fruits. The antimicrobial properties were investigated by minimum inhibitory concentration (MIC) and the inhibition area. The results identified the differences in antimicrobial activities attributed to different extraction methods. Enzyme-linked immunosorbent assay (ELISA) and Western Blot (WB) assay were conducted to assess the anti-inflammatory effects of ESD. In conclusion, our study suggested that EO from Alpinia zerumbet fruits might be a prospective candidate for antimicrobial and anti-inflammatory therapy.

Fabrication of a protein-dextran conjugates formed oral nanoemulsion and its application to deliver the essential oil from Alpinia zerumbet Fructus

The injury of vascular endothelial cells caused by high glucose (HG) is one of the driving factors of vascular complications of diabetes. Oral administration is the most common route of administration for the treatment of diabetes and its vascular complications. Essential oil extracts from Chinese medicine possess potential therapeutic effects on vascular endothelial injury. However, low solubility and volatility of essential oils generally result in poor oral absorption. Development of nanocarriers for essential oils is a promising strategy to overcome the physiological barriers of oral absorption. In this study, a nanoemulsion composed of bovine serum albumin (BSA)-dextran sulfate (DS) conjugate and sodium deoxycholate (SD) was constructed. The nanoemulsions were verified with promoted oral absorption and prolonged circulation time. After the primary evaluation of the nanoemulsion, essential oil from Alpinia zerumbet Fructus (EOFAZ)-loaded nanoemulsion (denoted as EOFAZ@BD5/S) was prepared and characterized. Compared to the free EOFAZ, EOFAZ@BD5/S increased the protective effects on HG-induced HUVEC injury in vitro and ameliorative effects on the vascular endothelium disorder and tunica media fibroelastosis in a T2DM mouse model. Collectively, this study provides a nanoemulsion for the oral delivery of essential oils, which holds strong promise in the treatment of diabetes-induced vascular endothelial injury.

Mesosphaerum suaveolens Essential Oil Attenuates Inflammatory Response and Oxidative Stress in LPS-Stimulated RAW 264.7 Macrophages by Regulating NF-κB Signaling Pathway

Mesosphaerum suaveolens (L.) Kuntze (Syn. Hyptis suaveolens (L.) Poit.) is a wild essential-oil-bearing plant having multiple uses in traditional medicine, perfumery, food, agriculture, and pharmaceutical industries. The present paper is the first report on the in vitro anti-inflammatory effects of the leaf essential oil of M. suaveolens (MSLEO) and unravels its molecular mechanism in LPS-stimulated RAW 264.7 macrophage cells. GC-MS analysis of the essential oil (EO) isolated from the leaves by hydro-distillation led to the identification of 48 constituents, accounting for 90.55% of the total oil, and β-caryophyllene (16.17%), phyllocladene (11.85%), abietatriene (11.46%), and spathulenol (7.89%) were found to be the major components. MSLEO treatment had no effect on the viability of RAW 264.7 cells up to a concentration of 100 μg/mL, and the EO was responsible for a reduction in proinflammatory cytokines like IL-6, IL-1β, and TNF-α, a decrease in intracellular ROS production, and the restoration of oxidative damage by elevating the levels of endogenous antioxidative enzymes like CAT, SOD, GPx, and GSH. RT-qPCR analysis indicated that MSLEO reduced the mRNA expression levels of iNOS and COX-2 as compared to the LPS-induced group. In addition, a confocal microscopy analysis showed that MSLEO inhibited the translocation of NF-κB from the cytosol to the nucleus. The results of this experiment demonstrate that MSLEO possesses significant anti-inflammatory potential by preventing the activation of NF-κB, which, in turn, inhibits the downstream expression of other inflammatory mediators associated with the activation of the NF-κB pathway in LPS-induced RAW 264.7 cells. Thus, the leaf essential oil of M. suaveolens may prove to be a promising therapeutic agent for the treatment of inflammation, and targeting the NF-κB signaling pathway may be considered as an attractive approach for anti-inflammatory therapies.

Essential Oils: Chemistry and Pharmacological Activities

In this review, we provide an overview of the current understanding of the main mechanisms of pharmacological action of essential oils and their components in various biological systems. A brief introduction on essential oil chemistry is presented to better understand the relationship of chemical aspects with the bioactivity of these products. Next, the antioxidant, anti-inflammatory, antitumor, and antimicrobial activities are discussed. The mechanisms of action against various types of viruses are also addressed. The data show that the multiplicity of pharmacological properties of essential oils occurs due to the chemical diversity in their composition and their ability to interfere with biological processes at cellular and multicellular levels via interaction with various biological targets. Therefore, these natural products can be a promising source for the development of new drugs.

Aromatic Plant-Based Functional Foods: A Natural Approach to Manage Cardiovascular Diseases

Aromatic plants and their essential oils have shown beneficial effects on the cardiovascular system and, therefore, are potential raw materials in the development of functional foods. However, despite their undeniable potential, essential oils present several limitations that need to be addressed, such as stability, poor solubility, undesirable sensory effects, and low bioavailability. The present review provides a current state-of-the-art on the effects of volatile extracts obtained from aromatic plants on the cardiovascular system and focuses on major challenges that need to be addressed to increase their use in food products. Moreover, strategies underway to overcome these limitations are pointed out, thus anticipating a great appreciation of these extracts in the functional food industry.

In vitro immunomodulatory activity study of Garcinia cowa Roxb. fraction

OBJECTIVES

The objective of this study is to determine the activity of Garcinia cowa Roxb. n-hexane, ethyl acetate, and butanol fractions as an immunomodulator in vitro and obtain the fraction that has the potential as an immunomodulator.

METHODS

Raw 264.7 macrophages were used to asses G. cowa Roxb. immunomodulatory activity. The MTT assay was chosen to measure cell viability to evaluate the cytotoxic effect on cells. ELISA method was used to measure the concentration of Interleukin-6 (IL-6) and Tumor Necrosis Factor Alpha (TNF-α) secreted by cells after being treated with G. cowa Roxb. fraction. The neutral red uptake assay determined the effect of Garcinia cowa Roxb. on the phagocytic activity.

RESULTS

After Raw 264.7 macrophages were given the Hexan fraction (Hex) at concentrations of 12.5 and 25 μg/mL, there was a decrease in the concentration of IL-6, TNF-α, and the phagocytosis index of cells. Administration of the Ethyl Acetate fraction (EtOAc) at concentrations of 12.5 and 25 μg/mL on cells caused a decrease in IL-6 and TNF-α levels but did not affect the phagocytosis index. There was an increase in the level of TNF-α and the phagocytosis index after being given the Butanol fraction (BuOH) with concentrations of 12.5 and 25 μg/mL but there was a slight decrease in the level of IL-6.

CONCLUSIONS

Both Hex and EtOAc fractions could suppress immune responses through decreasing IL-6, TNF-α, and slightly decreased phagocytic activity. BuOH fraction could stimulate immunomodulatory activities through enhanced TNF-α levels and phagocytic index, but less potent in enhancing IL-6 production. The BuOH fraction could be developed as an immunostimulant.

Margaritaria nobilis L.f. (Phyllanthaceae) Ethanolic Extract: Low Acute Oral Toxicity and Antinociceptive Activity

Margaritaria nobilis L.f. (Phyllanthaceae), a native Brazilian tree occurring mainly in the Amazon, is used in folk medicine for the treatment of abscesses (bark) and cancer-like symptoms (leaves). The present study evaluates the safety of its acute oral administration and its effects on nociception and plasma leakage. The chemical constitution of the leaf's ethanolic extract is determined by ultra-performance liquid chromatography-high-resolution mass spectrometry (LC-MS. Its acute oral toxicity is evaluated in female rats at a dose of 2000 mg/kg, evaluating the occurrence of deaths and Hippocratic, behavioral, hematological, biochemical, and histopathological changes, as well as food and water consumption and weight gain. Antinociceptive activity is evaluated in male mice with acetic-acid-induced peritonitis (APT) and formalin (FT) tests. An open field (OF) test is performed to verify possible interferences in the animals' consciousness or locomotion. LC-MS analysis shows the presence of 44 compounds classified as phenolic acid derivatives, flavonoids and O-glycosylated derivatives, and hydrolyzable tannins. No deaths or significant behavioral, histological, or biochemical changes are observed in the toxicity assessment. In nociception tests, M. nobilis extract significantly reduces abdominal contortions in APT, demonstrating selectivity for inflammatory components (FT second phase), not interfering in neuropathic components (FT first phase) or consciousness and locomotion levels in OF. Additionally, M. nobilis extract inhibits plasma acetic-acid-induced leakage. These data demonstrate the low toxicity of M. nobilis ethanolic extract, as well as its effectiveness in modulating inflammatory nociception and plasma leakage, possibly related to the flavonoids and tannins present in its composition.

Essential Oils from Mediterranean Plants Inhibit In Vitro Monocyte Adhesion to Endothelial Cells from Umbilical Cords of Females with Gestational Diabetes Mellitus

Essential oils (EOs) are mixtures of volatile compounds belonging to several chemical classes derived from aromatic plants using different distillation techniques. Recent studies suggest that the consumption of Mediterranean plants, such as anise and laurel, contributes to improving the lipid and glycemic profile of patients with diabetes mellitus (DM). Hence, the aim of the present study was to investigate the potential anti-inflammatory effect of anise and laurel EOs (AEO and LEO) on endothelial cells isolated from the umbilical cord vein of females with gestational diabetes mellitus (GDM-HUVEC), which is a suitable in vitro model to reproduce the pro-inflammatory phenotype of a diabetic endothelium. For this purpose, the Gas Chromatographic/Mass Spectrometric (GC-MS) chemical profiles of AEO and LEO were first analyzed. Thus, GDM-HUVEC and related controls (C-HUVEC) were pre-treated for 24 h with AEO and LEO at 0.025% v/v, a concentration chosen among others (cell viability by MTT assay), and then stimulated with TNF-α (1 ng/mL). From the GC-MS analysis, trans-anethole (88.5%) and 1,8-cineole (53.9%) resulted as the major components of AEO and LEO, respectively. The results in C- and GDM-HUVEC showed that the treatment with both EOs significantly reduced: (i) the adhesion of the U937 monocyte to HUVEC; (ii) vascular adhesion molecule-1 (VCAM-1) protein and gene expression; (iii) Nuclear Factor-kappa B (NF-κB) p65 nuclear translocation. Taken together, these data suggest the anti-inflammatory efficacy of AEO and LEO in our in vitro model and lay the groundwork for further preclinical and clinical studies to study their potential use as supplements to mitigate vascular endothelial dysfunction associated with DM.

In Vitro Anti-inflammatory Activity of Three Inula Species Essential Oils in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

In the face of the undesirable effects induced by anti-inflammatory drugs, there has been a return, nowadays, to the search for active ingredients based on plants. Herein, for the first time we study the anti-inflammatory activity of essential oils of three species of the genus Inula: Inula viscosa, Inula graveolens and Inula crithmoides in lipopolysaccharide (LPS)-activated macrophages. Essential oils have shown excellent preventive anti-inflammatory potential by causing inhibition of nitric oxide (NO) production in LPSactivated RAW264.7 macrophages with IC50s ranging between 15 and 35 µg  mL^− 1. On the other hand, the major acidic compounds, more precisely α- and β-costic acids, have been isolated from Inula viscosa and Inula graveolens essential oils and evaluated for their anti-inflammatory effect. These compounds appear to have a moderate preventive inhibitory effect on NO production relative to the significant effect generated by the neutral minority components present in the oils such as borneol, bornyl acetate, (E)-nerolidol, caryophyllene oxide, T-cadinol and eugenol. Therefore, we can deduce that the studied essential oils could be used as anti-inflammatory agents for the treatment of various inflammatory pathologies.

Agarwood Oil Nanoemulsion Attenuates Cigarette Smoke-Induced Inflammation and Oxidative Stress Markers in BCi-NS1.1 Airway Epithelial Cells

Chronic obstructive pulmonary disease (COPD) is an irreversible inflammatory respiratory disease characterized by frequent exacerbations and symptoms such as cough and wheezing that lead to irreversible airway damage and hyperresponsiveness. The primary risk factor for COPD is chronic cigarette smoke exposure, which promotes oxidative stress and a general pro-inflammatory condition by stimulating pro-oxidant and pro-inflammatory pathways and, simultaneously, inactivating anti-inflammatory and antioxidant detoxification pathways. These events cause progressive damage resulting in impaired cell function and disease progression. Treatments available for COPD are generally aimed at reducing the symptoms of exacerbation. Failure to regulate oxidative stress and inflammation results in lung damage. In the quest for innovative treatment strategies, phytochemicals, and complex plant extracts such as agarwood essential oil are promising sources of molecules with antioxidant and anti-inflammatory activity. However, their clinical use is limited by issues such as low solubility and poor pharmacokinetic properties. These can be overcome by encapsulating the therapeutic molecules using advanced drug delivery systems such as polymeric nanosystems and nanoemulsions. In this study, agarwood oil nanoemulsion (agarwood-NE) was formulated and tested for its antioxidant and anti-inflammatory potential in cigarette smoke extract (CSE)-treated BCi-NS1.1 airway basal epithelial cells. The findings suggest successful counteractivity of agarwood-NE against CSE-mediated pro-inflammatory effects by reducing the expression of the pro-inflammatory cytokines IL-1α, IL-1β, IL-8, and GDF-15. In addition, agarwood-NE induced the expression of the anti-inflammatory mediators IL-10, IL-18BP, TFF3, GH, VDBP, relaxin-2, IFN-γ, and PDGF. Furthermore, agarwood-NE also induced the expression of antioxidant genes such as GCLC and GSTP1, simultaneously activating the PI3K pro-survival signalling pathway. This study provides proof of the dual anti-inflammatory and antioxidant activity of agarwood-NE, highlighting its enormous potential for COPD treatment.

Essential Oils from Apiaceae, Asteraceae, Cupressaceae and Lamiaceae Families Grown in Serbia: Comparative Chemical Profiling with In Vitro Antioxidant Activity

The aim of the present study was to investigate the chemical profile and antioxidant activity of essential oils obtained from the most commonly grown plant species in Serbia. Aromatic and medicinal plants from Lamiaceae (Mentha x Piperita, Ocimum basilicum, Origanum majorana, Origanum vulgare, Salvia officinalis, Satureja hortensis, Satureja montana and Thymus vulgaris), Asteraceae (Ehinacea purpurea and Matricaria chamomilla), Apiaceae (Anethum graveolens, Carum carvi, Foeniculum vulgare, Petroselinum crispum and Pimpinella anisum) and Cupressaceae (Juniperus comunis) were selected as raw material for essential oils (EOs)' isolation. Hydrodistillation (HD) was used for the isolation of EOs while they were evaluated in terms of yield and terpenoid profiles by GC-MS. In vitro radical scavenging DPPH and ABTS⁺ radical activities were carried out for all EOs. Finally, a principal component analysis (PCA) was performed with the experimental results of the composition and antioxidant activity of the EOs, which showed a clear distinction between the selected plant species for the aforementioned responses. This work represents a screening tool for the selection of other EO candidates for further processing by emerging extraction techniques and the use of EOs as natural additives for meat products.

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.

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.