Anti-inflammatory Study on the Constituents of Angelica sinensis (Oliv.) Diels, Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav., Angelica pubescence Maxim and Foeniculum vulgare Mill. Essential Oils.

Umbelliferae plants, which are widely used as traditional Chinese medicine because of their characteristics of relieving rheumatism, alleviating fever, circulating blood and easing pain. This experimental study was based on ear edema model caused by 12-O-tetracycline-propylphenol-13-acetic acid (TPA) in mice and compared with the Ibuprofen (Ib) group. Gas chromatography-mass spectrometry (GC-MS) was used to analyse the composition of the essential oils from the four studied Umbelliferae plants (Angelica sinensis (Oliv.) Diels, A. dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav., A. pubescens Maxim and Foeniculum vulgare Mill.). Biologically active components in volatile oils from the four studied Umbelliferae plants were evaluated. The expression levels of inflammatory cytokines Tumor Necrosis Factor-α (TNF-α), Cyclooxygenase-2 (COX-2), Interleukin-6 (IL-6) and RelA (p65) in mouse skin were determined by immunohistochemical method. The refractive index of the four essential oils was calculated. A total of 239 compounds were identified by GC-MS from the four studied plants, and the main constituents were osthole (44.61%, APEOs), obepin (0.59%, APEOs & 86.58%, FVEOs), undecanol (8.58%, ADEOs), α-muurolene (7.95%, ADEOs) and cis-anethol (9.11%, ADEOs). E-ligustilide (0.14%, APEOs & 81.14%, ASEOs), (-)-spathulenol (0.08%, FVEOs & 1.21%, ASEOs), (-)-terpinen-4-ol (4.91%, FVEOs), 2-butylthiolane (5.76%, APEOs) and α-bisabolol (3.80%, APEOs). This study showed that all the essential oils from the four studied Umbelliferae plants contained various lactones, including ligustrongolactone, trans-anisol and imperatorin. According to the results of the TPA induction test in the mouse ear edema model, the essential oils of four Umbelliferae plants reduced the levels of inflammatory cytokines TNF-α, COX-2, IL-6 and p65. All of them showed extraordinary biological activity in anti-inflammatory, so they have potential application value for biomedical products, pharmaceutical preparations, natural functional nutrients and cosmetic additives.

Chemical constituents, biological activities and anti-rheumatoid arthritic properties of four citrus essential oils.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease with predominant synovitis that has no complete cure or preventive treatment. Citrus essential oils, used in natural fragrances, contain a variety of functional ingredients that are worthy of investigation for their potential as natural anti-inflammatory drug sources. In this study, essential oils were hydro distilled from the peels of four citrus species: Citrus sinensis (L.) Osbeck (CSEOs), Citrus paradisi Macfad. (CPEOs), Citrus limon (L.) Osbeck (CLEOs) and Citri Reticulatae Pericarpium (CREOs). Altogether, 81 compounds were identified using gas chromatography-mass spectrometry (GC-MS), of which d-limonene (17.96%-94.66%) was an abundant component of all four oils. The stable 1,1-diphenyl-2-pyrrole hydrazine (DPPH) free radical test showed that all four essential oils had excellent antioxidant properties (IC50 , 0.76-13.86 µg/mL). Furthermore, the oils remarkably increased the first G1 phase of the cell cycle, which inhibited the pro-inflammatory factor expression. An immunohistochemical analysis indicated that the four essential oils inhibited the expression of tumor necrosis factor-α and cyclooxygenase-2 and they exhibited anti-inflammatory activity in a rat model that was similar to that of the common drug, Ibuprofen. These results show that the CSEOs, CPEOs, CLEOs, and CREOs have significant antirheumatic activities and thus have great potential in developing functional food or drugs for treating RA.

Variation in Compositions and Biological Activities of Essential Oils from Four Citrus Species: Citrus limon, Citrus sinensis, Citrus paradisi, and Citrus reticulata.

Species of the genus Citrus are cultivated in many regions of China and are widely used for medicinal purposes. In the present study, essential oils (EOs) were extracted from four different Citrus species using steam distillation. The chemical components of these four essential oils were separated using gas chromatography-mass spectrometry, and 52 compounds were confirmed. D-limonene was found to be the most abundant compound. All four essential oils demonstrated varied but remarkable radical scavenging capacity (IC50 ; 0.77-13.9 %). Citrus paradisi essential oil exhibited excellent antioxidant activity. Compared to ibuprofen, topical application of the four Citrus spp. essential oils significantly inhibited ear edema formation in mice. Furthermore, essential oils from the four Citrus species reduced the expression levels of interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and nuclear transcription factor kappa B p65 (NF-κB) to different degrees. The cytotoxicity of the four essential oils on BV2 microglial cells was determined using the MTT assay (IC50 ; 321.37-1558.87 µg/mL), wherein Citrus limon essential oil showed the lowest cytotoxicity. The essential oils of Citrus limon, Citrus reticulata, and Citrus paradisi had an inhibitory effect on the lung cancer cell lines H1299 by inducing a G0/G1 cell cycle arrest. Cluster and principal component analyses were used to determine the relationship among the Citrus species. These results suggest that the four Citrus essential oils have potential for use as active ingredients in functional foods or cosmeceutical products.

A comparative study on chemical compositions and biological activities of four essential oils: Cymbopogon citratus (DC.) Stapf, Cinnamomum cassia (L.) Presl, Salvia japonica Thunb. and Rosa rugosa Thunb.

ETHNOPHARMACOLOGICAL RELEVANCE: Essential oils (EOs) are important active ingredients in Chinese herbal medicine. Cymbopogon citratus (DC.) Stapf, Cinnamomum cassia (L.) Presl, Salvia japonica Thunb., and Rosa rugosa Thunb. are used in local and traditional medicine to treat inflammation-related diseases. While the constituents and bioactivities of EOs of the above four Chinese herbals have been reported previously, but their anti-inflammatory and antioxidant activities have not been systematically evaluated. AIM OF THE STUDY: The purpose of this study was to research the chemical constituents, anti-inflammatory activities, and antioxidant activities of EOs of four Chinese herbal medicines. MATERIALS AND METHODS: Fresh plant materials were collected both in August 2018. The compositions of EOs were determined by the gas chromatography-mass spectrometry (GC-MS) method. TPA (12-O-tetradecylphophenol-13-acetate)-induced mouse ear model was evaluated the anti-inflammatory activities of EOs. The reduction of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and RelA protein of the nuclear factor kappa-B (NF-κB) in the signal pathway (P65) were measured. The antioxidant activities of EOs from four plants were determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. RESULTS: A total of 217 compounds were separated and identified from four EOs, mainly including trans-cinnamylaldehyde (68.75%), citronellal (38.16%), linalool (1.02-33.73%), geraniol (19.39%) and citronellol (17.18%). All four EOs reduced the damage of the ear tissue and had certain anti-inflammatory effects, and the EOs of C. citratus (CyCEOs) and S. japonica (SJEOs) had the best anti-inflammatory activities among others, even better than ibuprofen. The four EOs exhibited different DPPH radical-scavenging activities (IC50, 0.101-1.017%), where most of them were much lower than that of EOs of C. citratus (CiCEOs) (IC50, 0.101%) and EOs of R. rugosa (RREOs) (IC50, 0.142%). CONCLUSIONS: The main components determine diverse propertise of these four EOs, our results suggested that four EOs presented anti-inflammatory and antioxidant effect via reducing the expression of TNF-a, IL-6, COX-2, and NF-κB p65, which may provide a new approach for development of new anti-inflammatory drugs.