Anti-inflammatory Effects Of Essential Oil Research Articles

Anti-Inflammatory Effects of Essential Oils from the Peels of Citrus Cultivars.

Citrus cultivars have remarkable health benefits, but only the anti-inflammatory activities of the major varieties have been studied. This study investigated the anti-inflammatory effects of various citrus cultivars and their active anti-inflammatory components. The essential oils of 21 citrus peels were extracted via hydrodistillation using a Clevenger-type apparatus, and the chemical compositions of the essential oils were analyzed. D-Limonene was the most abundant constituent. To evaluate the anti-inflammatory effects of the citrus cultivars, the gene expression levels of an inflammatory mediator and proinflammatory cytokines were investigated. Among the 21 essential oils, those extracted from C. japonica and C. maxima exhibited superior anti-inflammatory activities, being able to inhibit the expression of the inflammatory mediators and proinflammatory cytokines in lipopolysaccharide-stimulated RAW 264.7 cells. The essential oils of C. japonica and C. maxima were distinguished into seven distinct constituents, α-pinene, myrcene, D-limonene, β-ocimene, linalool, linalool oxide, and α-terpineol, compared with other essential oils. The anti-inflammatory activities of the seven single compounds significantly inhibited the levels of inflammation-related factors. In particular, α-terpineol exhibited a superior anti-inflammatory effect. This study showed that the essential oils from C. japonica and C. maxima exhibit high anti-inflammatory activity. In addition, α-terpineol is an active anti-inflammatory compound that contributes to inflammatory responses.

Anti-inflammatory effect of essential oil from Amomum Tsaoko Crevost et Lemarie

Amomum Tsaoko Crevost et Lemarie is a kind of spices and traditional Chinese medicines with great commercial value. Traditional treatment often uses essential oils from Amomum Tsaoko in aromatherapy. In this study, researchers analyzed the composition of steam-distilled essential oil from Amomum tsaoko (ATEO) and evaluated its potential antioxidant and anti-inflammatory activity. GC–MS identified a total of 33 volatile compounds, the majority of which were alcohol (1,8-cineole and nerol) and aldehyde ((2E)-2-decenal) compounds. Additionally, ATEO showed great anti-inflammatory activity in LPS-induced RAW 264.7 macrophages. ATEO markedly inhibited the nitric oxide (NO) release, and decreased the expression level of TNF-α, IL-1β, IL-6 and monocyte chemotactic protein-1 (MCP-1) in a dose-dependent manner. Furthermore, ATEO significantly reduced the expression of iNOS, COX-2, NF-κB p-p65 and p-ERK. These results suggested that ATEO has great anti-inflammatory activity in LPS-induced RAW 264.7 cells, which will facilitate the development of ATEO as a functional food.

Chemical composition and anti-inflammatory activity of essential oils from resin of Commiphora species

ABSTRACT. Essential oils (EOs) were prepared by the hydro-distillation technique from the resins of four Commiphora species and analyzed by GC-MS. Major constituents of EOs were a-copaene (22.71%), β-caryophyllene (28.03%) and β-caryophyllene oxide (13.89%) for C. sphaerocarpa; a-pinene (29.1%) for C. africana; hexadecane (14.1%) for C. habessinica and δ-cadinene (31.5%) for C. schimperi. We investigated the anti-inflammatory effects of EOs in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages by measuring nitric oxide (NO). The effect in mRNA or protein level after EO treatment were evaluated by RT-PCR and Western blot analysis, respectively. Among four Commiphora species, C. sphaerocarpa EO demonstrated a significant inhibition of LPS by 27.2±3.6% at 10 μg/mL and 62.3±5.2% at 20 μg/mL. C. sphaerocarpa EO inhibited LPS mediated iNOS over expression in both protein and mRNA level with dose dependent manner. It inhibited phosphorylation of ERK1/2, p38, ATF2. The enhanced anti-inflammatory activity of the EO of the plant was due to HO-1 expression by ROS dependent Nrf2 activation in RAW264.7 cells. These findings indicate C. sphaerocarpa EO inhibits the pro-inflammatory responses by inhibiting MAPK/ATF2, and triggering ROS/Nrf2/HO-1 signaling. Therefore, C. sphaerocarpa EO could have potential for useful therapeutic candidate preventing and treating inflammatory diseases.
 
 KEY WORDS: GC-MS, Anti-inflammatory, C. africana, C. habessinica, C. sphaerocarpa, C. schimperi
 
 Bull. Chem. Soc. Ethiop. 2022, 36(2), 399-415. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i2.13

Essential Oils from Zingiber striolatum Diels Attenuate Inflammatory Response and Oxidative Stress through Regulation of MAPK and NF-κB Signaling Pathways.

Zingiber striolatum Diels (Z. striolatum), a widely popular vegetable in China, is famous for its medicinal and nutritional values. However, the anti-inflammatory effects of essential oil from Z. striolatum (EOZS) remain unclear. In this study, EOZS from seven regions in China were extracted and analyzed by GC–MS. LPS-induced RAW264.7 cells and 12-O-Tetradecanoylphorbol 13-acetate (TPA)-stimulated mice were used to evaluate the anti-inflammatory effects of EOZS. Results show that 116 compounds were identified in EOZS from seven locations. Samples 2, 4 and 5 showed the best capability on DPPH radical scavenging and NO inhibition. They also significantly reduced the production of ROS, pro-inflammatory cytokines, macrophage morphological changes, migration and phagocytic capability. Transcriptomics revealed MAPK and NF-κB signaling pathways may be involved in the anti-inflammatory mechanism, and the predictions were proven by Western blotting. In TPA-induced mice, EOZS reduced the degree of ear swelling and local immune cell infiltration by blocking the activation of MAPK and NF-κB signaling pathways, which was consistent with the in vitro experimental results. Our research unveils the antioxidant capability and potential molecular mechanism of EOZS in regulating inflammatory response, and suggests the application of EOZS as a natural antioxidant and anti-inflammatory agent in the pharmaceutical and functional food industries.

Antioxidant and anti-inflammatory properties of essential oils from three Eucalyptus species

Abstract Eucalyptus essential oils are used as traditional medicines in many countries. The objective of this study was to evaluate the antioxidant and anti-inflammatory activities of leaf essential oils extracted from three different Eucalyptus species on HepG2 and RAW264.7 cells. Essential oils were distilled from fresh leaf samples, and the chemical constituents were analyzed using gas chromatography–mass spectrometry. The antioxidant activities of essential oils were determined using ABTS and hydroxyl radical scavenging assays, and hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells. Additionally, lipopolysaccharide (LPS)-activated RAW264.7 macrophages were used to evaluate the anti-inflammatory properties. The results revealed that Eucalyptus citriodora and Eucalyptus urophylla leaf essential oils had a high content of oxygenated monoterpenes, whereas Eucalyptus deglupta contained a high amount of monoterpene hydrocarbons. Essential oils extracted from the three Eucalyptus species showed antioxidant and anti-inflammatory activities. E. citriodora and E. urophylla leaf essential oils had strong antioxidant activity against H2O2-induced oxidative stress in human HepG2 cells. Additionally, E. citriodora leaf essential oil, which contains a high amount of citronellal, exhibited the most potent anti-inflammatory activity in LPS-activated RAW264.7 macrophages. The antioxidant and anti-inflammatory effects of essential oils depended on their chemical composition. A principal component analysis explained 100% of the variance was performed to construct three groups based on the chemical components and antioxidant and anti-inflammatory activities. This study suggests that E. citriodora leaf essential oil, which represents a good source of oxygenated monoterpenes, could be considered a potential phytochemical agent for the prevention of oxidative stress and inflammation. Keywords: Antioxidant, Anti-inflammatory effect, Eucalyptus essential oils, Gas chromatography–mass spectrometry, Principal component analysis

Anti-inflammatory effect of essential oil extracted from Pinus densiflora (Sieb. et Zucc.) wood on RBL-2H3 cells

The aim of this study is to identify the active compounds of the essential oil extracted from the Pinus densiflora (Sieb. et Zucc.) wood using the hydrodistillation method and evaluate their anti-inflammatory activity. The chemical composition of the oil was identified by GC–MS analysis, and its anti-inflammatory activity was assessed by investigating its effect on the expression of interleukin-4 (IL-4), interleukin-13 (IL-13), and β-hexosaminidase in lipopolysaccharide (LPS)-stimulated RBL-2H3 cells. Treatment of the LPS-stimulated RBL-2H3 cells with the oil and its fractions downregulated the production of pro-inflammatory cytokines such as IL-4 and IL-13 and further attenuated the secretion of β-hexosaminidase out of the cells to a significant level. Among the five obtained fractions, fraction E exhibited the best anti-inflammatory activity, and its main constituent, longifolene, was considered as the active compound. Moreover, the inhibitory effect of longifolene on the expression levels of IL-4 and IL-13 and the β-hexosaminidase secretion was similar to that of the P. densiflora wood oil, indicating longifolene as the active constituent of the P. densiflora wood oil with immunosuppressive effects on inflammation.

Chemical Composition of Pinus brutia Ten Essential Oil and Its in vitro Anti-Inflammatory Activity

This investigation aims to determine the chemical composition of Pinus brutia leaves essential oil and evaluate its anti-inflammatory property using Human Red Blood Cells (HRBC) membrane stabilization assay and Albumin denaturation assay. The chemical composition of essential oil (EO) obtained by hydro-distillation of leaves of Pinus brutia was investigated by GC-MS. The anti-inflammatory effect of EO was evaluated using Human Red Blood Cells (HRBC) membrane stabilization assay and Albumin denaturation assay. The main constituents of EO were α-Terpineol (66.16%), 3-Carene (4.90%), Carveol (4.55%) and cis-Verbenol (3.22%). The inhibion of hemolysis was observed at concentrations (2.5-12.5) µg/ml. Moreover, albumin denaturation test showed protection effect at concentrations (8-40) µg/ml. We concluded that, Pinusbrutia EO shows strong anti-inflammatory activity at different concentration when compared to standard drug of Diclofenac sodium. In addition, GC-MS analysis of Pinus brutia EO showed the presence of α-Terpineol as major compound in the oil. It reveals that this constituent is responsible to maximum protection of albumin denaturation and membrane stabilization assay. The future work will be determination of anti-inflammatory by in vivo models.

Anti-nociceptive and anti-inflammatory effects of Ferulago angulata

Introduction: Ferulago angulata from the Apiaceae family, has high flavonoid content and is detected to have anti-nociceptive and anti-inflammatory effects. Objectives: In this study, we sought to determine the components of essential oil and to estimate total phenol and flavonoid contents of its various extracts. We also aimed to find out the anti-nociceptive and anti-inflammatory effects of essential oil, hydro-alcoholic and phenolic extracts of F. angulata aerial parts. Materials and Methods: The plant’s essential oil and extracts were prepared according to standard methods. Acetic acid, hot plate and formalin tests were used to investigate anti-nociceptive effects. Additionally, carrageenan and croton oil tests were used to evaluate anti-inflammatory effects. Results: Ferulago angulata aerial parts yielded 0.2% (v/w) yellowish essential oil. The gas chromatography/ mass spectrometry (GC-MS) of essential oil identified 82 compounds, which represented 98.9% of the essential oil. Thymol (7.9%), spathulenol (6.5%), trans-anethol (6.4%), myristicin (5.1%) and alpha-pinene (4.5%) were the main components. In acetic acid and formalin tests, the essential oil, hydro-alcoholic and phenolic extracts showed significant anti-nociceptive effects (P<0.001). In hot plate test, morphine which was used as standard drug, revealed significant anti-nociceptive effect while the plant extracts and essential oil were ineffective. High dose of the extracts and essential oil in croton oil test (P<0.001) and high dose of hydro-alcoholic and phenolic extracts in carrageenan test (P<0.05) reduced the inflammation. Conclusion: Ferulago angulata extracts and essential oil have anti-nociceptive and anti-inflammatory effects. However, further studies are needed to clarify their mechanism of actions.

Anti-Inflammatory Effect of Essential Oils Extracted from Wood of Four Coniferous Tree Species

The aim of this study was to evaluate the anti-inflammatory effects of essential oils extracted from the wood of Chamaecyparis obtusa, Pinus densiflora, Pinus koraiensis, and Larix kaempferi. Essential oils were extracted by hydrodistillation, and their chemical components were determined by GC/MS. Major chemical components of these essential oils were α-cadinol (19.25%), τ-muurolol (14.20%), and α-pinene (13.74%) in C. obtusa; α-pinene (47.16%), longifolene (14.31%), β-phellandrene (11.78%), and β-pinene (11.02%) in P. densiflora; α-pinene (13.49%) and longifolene (10.79%) in P. koraiensis, and geranyl linalool (23.58%) and α-pinene (18.57%) in L. kaempferi. To evaluate the anti-inflammatory effects of essential oils, lipopolysaccharide (LPS)-induced RBL-2H3 mast cells were treated with these essential oils; then, the changes in the mRNA expression level of the cytokines IL-4 and IL-13 were examined. Further, degranulation was evaluated by measuring β-hexosaminidase release. After LPS-induced RBL-2H3 mast cells were exposed to 10−7% of all types of essential oils, the gene expression levels of IL-4 and IL-13 within the cells remarkably decreased. The relative mRNA expression level of IL-4 was 69.6% in P. densiflora, 63.2% in P. koraiensis, 55.1% in C. obtusa, and 45.8% in L. kaempferi compared with that in the group treated with LPS. The mRNA expression level of L-13 should a similar trend. The inhibitory rate of IL-13 mRNA expression of P. densiflora, P. koraiensis, C. obtusa, and L. kaempferi was 57.8%, 57.1%, 51.1%, and 34.5%, respectively. β-Hexosaminidase release significantly decreased following the treatment with the four types of essential oils. The rate of β-hexosaminidase release were 38.1% C. obtusa; 33.0% P. densiflora; 27.4% P. koraiensis; and 9.1% L. kaempferi. Among all types of essential oils, that extracted from P. densiflora wood showed the highest anti-inflammatory activity. These results show that the tested essential oils exert an anti-inflammatory effect through the inhibition of degranulation and expression of cytokines.

Chemical composition and anti-inflammatory activity of the essential oil from the leaves of Limnocitrus littoralis (Miq.) Swingle from Vietnam

The oil from the leaves of Limnocitrus littoralis (Miq.) Swingle was obtained by hydrodistillation and investigated by gas chromatography combined with mass spectrometry (GC/MS), the anti-inflammatory effect of the oil was examined on a LPS-induced RAW264.7 cells. An aggregate of forty components were identified, representing 93.0% of the oil. This oil was subjugated by monoterpene hydrocarbons (27.7%), sesquiterpene hydrocarbons (32.3%) and oxygenated sesquiterpenes (4.6%). The significant constituents of L. littoralis essential oil were determined as follows; myrcene (24.9%), γ–muurolene (11.0%), and oleic acid (10.3%). The essential oil of L. littoralis showed activity against the nitric oxide (NO) generation with the IC50 value to 12.50 ± 1.19 µg/L. The anti-inflammatory effect of essential oil from the leaves of L. littoralis is reported for the first time.

Oregano Essential Oil Attenuates RAW264.7 Cells from Lipopolysaccharide-Induced Inflammatory Response through Regulating NADPH Oxidase Activation-Driven Oxidative Stress.

Oregano is an aromatic plant widely distributed throughout the Mediterranean area and in Asia. Recent studies have revealed that the anti-inflammatory effect of essential oil in this plant. However, the mechanisms underlying the therapeutic potential have not been well elucidated. This study determined whether oregano essential oil (OEO) exerts an anti-inflammatory effect on lipopolysaccharide (LPS)-treated murine macrophage cells (RAW264.7 cells) in vitro and elucidated the possible underlying molecular mechanisms. The results showed that OEO (2.5–10 μg/mL) inhibited the expression and secretion of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in RAW264.7 cells treated with LPS (1 μg/mL). Consistent with the pro-inflammatory gene expression, the OEO treatment efficiently reduced the LPS-induced activation of mitogen-activated protein kinase, protein kinase B, and nuclear factor κB in RAW264.7 cells. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibition in Nox2 protein-silenced cells attenuated the mRNA expression of IL-1β, IL-6, and TNF-α in the LPS-induced RAW264.7 cells. The OEO inhibited the LPS-induced elevation of NADPH oxidase and oxidative stress. This result suggests that LPS induces RAW264.7 cell inflammation through the NADPH oxidase-mediated production of reactive oxygen species (ROS). In conclusion, OEO protects against the LPS-induced RAW264.7 cell inflammatory response through the NADPH oxidase/ROS pathway.

Anti-Inflammatory Effects of Chamaecyparis Obtusa Essential Oil on Peripheral Blood Mononuclear Cells

Background and Objectives The biological activity in antibacterial and antioxidative action of essential oils (EOs) have been investigated. In this study, we tried to evaluate the effects of Chamaecyparis obtusa EOs on producing chemical mediators by peripheral blood mononuclear cells (PBMCs). Subjects and Method PBMCs from healthy volunteers were stimulated with lipopolysaccharide (LPS) and phytohaemagglutinin (PHA) in the presence of varying concentrations of EOs. Cytotoxic effects of EOs were measured using an aqueous cell proliferation assay kit and supernatants were analyzed using enzyme-linked immunosorbent assay. Tumor necrosis factor-α (TNF-α), interleukin-5, and interferon-γ (INF-γ) protein levels were measured to determine the anti-inflammatory effects of essential oil. Results EOs were found to have cytotoxic effects on PBMCs at levels of over 1%. EOs not only could induce PBMCs to produce chemical mediators, but it also significantly inhibited the LPS induced TNF-α and INF-γ productions as well as the PHA induced INF-γ production. Conclusion EOs had cytotoxic effects at high concentrations and modulated chemical mediator productions from PBMC. These data suggest that EOs could be used to treat immunologic or inflammatory diseases. Key words: Anti-inflammation ㆍ Chamaecyparis obtusa ㆍ Essential oil ㆍ Peripheral blood mononuclear cell

Anti-inflammatory Effect of Essential Oil from Citrus aurantium L. var. amara Engl.

Essential oil has been popularly used as an alternative for the treatment of inflammation. The bioactivities of essential oil from blossoms of Citrus aurantium L. var. amara Engl (CAVAO) showed greater anti-inflammation potential than that of antioxidant, anticancer, and 3T3-L1 proliferation inhibition. CAVAO (250 μg/mL) significantly inhibited production of nitric oxide (NO) (99.54 ± 2.81%), interleukin-6 (IL-6) (98.11 ± 1.62%), tumor necrosis factor-α (TNF-α) (41.84 ± 1.52%), and interleukin-1β (IL-1β) (56.09 ± 2.21%) as well as their gene expression level. CAVAO also markedly decreased the expression levels of cyclooxygenase-2 (COX-2) gene and protein. Furthermore, CAVAO inhibited nuclear factor-κB (NF-κB) activation, which was justified by the inhibitory effect on NF-κB nuclear translocation, IκBα phosphorylation and degradation, and phosphorylation-dependent IκB kinase activation in RAW264.7 cells stimulated with lipopolysaccharides. CAVAO also suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and p38, indicating that mitogen-activated protein kinase (MAPK) signaling pathways were also blocked. The major constituents of CAVAO were characterized as linalool (64.6 ± 0.04%), α-terpineol (7.61 ± 0.03%), (R)-limonene (6.15 ± 0.04%), and linalyl acetate (5.02 ± 0.03%), which might be responsible for its observed anti-inflammation activity. It is concluded that CAVAO has great potential to be developed into a functional food for the treatment of inflammatory-associated diseases.

Anti-Inflammatory Effects of Essential Oils from Rosmarinus officinalis and Populus alba on Experimental Models of Acute and Chronic Inflammation in Rats

Anti-Inflammatory Effects of Essential Oils from Rosmarinus officinalis and Populus alba on Experimental Models of Acute and Chronic Inflammation in Rats

Phytochemical Analysis and Pharmacological Activities of Methanolic Extract and Essential Oil from Rhizomes of Alpinia malaccensis (Burm. f.) Roscoe

The present study describes chemical composition, antipyretic, analgesic and anti-inflammatory effects of essential oil and methanolic extract from rhizomes of Alpinia malaccensis. Fifty nine components were identified by gas chromatography and gas chromatography-mass spectrometry with eucalyptol (18.0%), and α-fenchyl acetate (16.7%), as the major constituents. The methanolic extract of A. malaccensis exhibited good anti-inflammatory effect (32.69%) by carrageenan induced method at a dose of 100 mg/kg b.wt. after 24 hours compared with essential oil. In acetic acid induced writhing test, essential oil exhibited significant (p<0.05) analgesic effect at both doses of 50 and 100 mg/kg b.wt. with 41.39% inhibition of writhes at 100 mg/kg b.wt. in comparision to its methanolic extract. For antipyretic activity by brewer's yeast suspension method, both essential oil and methanolic extracts exhibited significant pyrexia (p<0.05) for 50 mg/kg b.wt. and 100 mg/kg b.wt. in a dose dependent manner. The present study provided the scientific justification about the antipyretic, analgesic and anti-inflammatory properties of the essential oils and methanolic extract from A. malaccensis, thus validating its use in traditional folk medicines and hence supporting the development in the pharmacological properties of bioactive natural substances.

Essential oil of Artemisia argyi suppresses inflammatory responses by inhibiting JAK/STATs activation

Ethnopharmacological relevanceArtemisia argyi is a herbal medicine traditionally used in Asia for the treatment of bronchitis, dermatitis and arthritis. Recent studies revealed the anti-inflammatory effect of essential oil in this plant. However, the mechanisms underlying the therapeutic potential have not been well elucidated. The present study is aimed to verify its anti-inflammatory effect and investigate the probable mechanisms. Materials and methodsThe essential oil from Artemisia argyi (AAEO) was initially tested against LPS-induced production of inflammatory mediators and cytokines in RAW264.7 macrophages. Protein and mRNA expressions of iNOS and COX-2 were determined by Western blotting and RT-PCR analysis, respectively. The effects on the activation of MAPK/NF-κB/AP-1 and JAK/STATs pathway were also investigated by western blot. Meanwhile, in vivo anti-inflammatory effect was examined by histologic and immunohistochemical analysis in TPA-induced mouse ear edema model. ResultsThe results of in vitro experiments showed that AAEO dose-dependently suppressed the release of pro-inflammatory mediators (NO, PGE2 and ROS) and cytokines (TNF-α, IL-6, IFN-β and MCP-1) in LPS-induced RAW264.7 macrophages. It down-regulated iNOS and COX-2 protein and mRNA expression but did not affect the activity of these two enzymes. AAEO significantly inhibited the phosphorylation of JAK2 and STAT1/3, but not the activation of MAPK and NF-κB cascades. In animal model, oral administration of AAEO significantly attenuated TPA-induced mouse ear edema and decreased the protein level of COX-2. ConclusionAAEO suppresses inflammatory responses via down-regulation of the JAK/STATs signaling and ROS scavenging, which could contribute, at least in part, to the anti-inflammatory effect of AAEO.

Analgesic and Anti-Inflammatory Effects of Essential Oils of Vitex agnuscastus L. from South-West of Algeria

Analgesic and Anti-Inflammatory Effects of Essential Oils of Vitex agnuscastus L. from South-West of Algeria

Anti-inflammatory effects of essential oils from Mangifera indica.

Mangifera indica is widely found in Brazil, and its leaves are used as an anti-inflammatory agent in folk medicine. The aim of this study is to perform composition analysis of essential oils from the M. indica varieties, espada (EOMIL1) and coração de boi (EOMIL2), and confirm their anti-inflammatory properties. Twenty-three volatile compounds were identified via gas chromatography-mass spectrometry (GC-MS) in two essential oils from the leaves. Paw edema and myeloperoxidase (MPO) activity were evaluated using the carrageenan-induced paw model, while leukocyte migration was analyzed using the pleurisy model. At oral doses of 100 and 300 mg/kg, the essential oils significantly reduced edema formation and the increase in MPO activity induced by carrageenan in rat paws. For a dose of 300 mg/kg EOMIL1, 62 ± 8% inhibition of edema was observed, while EOMIL2 led to 51 ± 7% inhibition of edema. At a dose of 100 mg/kg, the inhibition was 54 ± 9% for EOMIL1 and 37 ± 7% for EOMIL2. EOMIL1 and EOMIL2 significantly reduced MPO activity at doses of 100 mg/kg (47 ± 5 and 23 ± 8%, respectively) and 300 mg/kg (50 ± 9 and 31 ± 7%, respectively). In the pleurisy model, inhibitions were also observed for EOMIL1 and EOMIL2 in the leukocyte migration test. The results of the present study show that essential oils from M. indica differ in chemical composition and anti-inflammatory activity in rats.

Anti-inflammatory effects of essential oils extracted from Chamaecyparis obtusa on murine models of inflammation and RAW 264.7 cells.

Antimicrobial, antifungal and anti-inflammatory effects of essential oils extracted from Chamaecyparis obtusa (EOCO) have previously been reported. In the present study, the anti-inflammatory effects of EOCO were investigated in two murine models of inflammation: Carrageenan-induced paw edema and thioglycollate-induced peritonitis, and in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The expression levels of proinflammatory cytokines were analyzed by ELISA, the expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were determined by western blotting, and nitrite concentration was measured using Griess reagent. In mice with carrageenan-induced edema, paw thickness and the expression levels of interleukin (IL)‑1β and IL-6 in paw homogenates were significantly decreased in the EOCO (5 and 10 mg/kg) group, as compared with the control group. In mice with thioglycollate-induced peritonitis, treatment with EOCO (5 and 10 mg/kg) reduced the number of total cells and suppressed tumor necrosis factor‑α (TNF‑α), IL‑1β and IL‑6 levels in peritoneal fluid. In addition, EOCO reduced nitric oxide, TNF‑α and IL‑6 production, and suppressed iNOS and COX‑2 expression in LPS‑stimulated RAW 264.7 cells. These results suggest that EOCO may exert anti‑inflammatory effects in vivo and in vitro, and that these effects may be associated with the inhibition of inflammatory mediators. Therefore, EOCO may be considered an effective therapeutic agent for the treatment of inflammatory diseases.

Antinociceptive and anti-inflammatory effects of essential oil extracted from Chamaecyparis obtusa in mice

Essential oil extracted from Chamaecyparis obtusa (EOCO) consists of several monoterpenes with anti-inflammatory effects. Monoterpenes are expected to have an analgesic effect through inhibition of pro-inflammatory mediators. The present study investigated the anti-nociceptive and anti-inflammatory effects of EOCO in animal models of pain. Intraperitoneal injection with EOCO (5 or 10mg/kg), aspirin (positive control, 300mg/kg), or DMSO (negative control) was performed 1h before the nociception tests: acetic acid-induced writhing response, formalin test, and hot plate test in mice, and acidic saline-induced allodynia in rats. The expression of pro-inflammatory cytokines and pro-inflammatory enzymes in formalin-injected paws was determined by ELISA and western blotting, respectively. Treatment with EOCO significantly reduced acetic acid-induced writhing and paw-licking time in late response of the formalin tests. The anti-nociceptive effect was comparable with aspirin. However, EOCO did not affect the reaction time of licking of the hind paws or jumping in hot plate test and the mechanical withdrawal thresholds in acidic saline-induced allodynia model. Formalin-injected paws of mice treated with EOCO revealed the down-regulated expression of tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, and cyclooxygenase-2, as compared with those of control mice. These data showed the anti-nociceptive and anti-inflammatory effects of EOCO. The pain-relieving effect might be attributed to inhibition of peripheral pain in association with inflammatory response. EOCO could be a useful therapeutic strategy to manage pain and inflammatory diseases.