Chemical composition and anti-inflammatory activities of essential oil from Trachydium roylei

Chemical Composition of Litsea pungens Essential Oil and Its Potential Antioxidant and Antimicrobial Activities

Litsea pungens is a plant with medicinal and edible properties, where the fruits are edible and the leaves have medicinal properties. However, there is limited research on the chemical and pharmacological activities of the plant. In this study, essential oils were extracted by steam distillation and their antioxidant and antibacterial activities were further evaluated. Gas chromatography-mass spectrometry (GC-MS) was used to identify the chemical components of L. pungens fresh fruit essential oil (FREO) and L. pungens fresh flower essential oil (FLEO), rapeseed oil (RO) and commercial Litsea oil (CEO). The results showed that 12 chemical components were identified in FREO. Twelve chemical components were identified from FLEO, four chemical components were identified from CEO, and thirteen chemical components were identified from RO. Except for RO, the other three oils were mainly composed of terpenes, among which limonene is the main chemical component. In terms of antioxidant activity, FREO, FLEO, CEO and RO have antioxidant capacity, mainly reflected in the scavenging DPPH free radicals and the iron ion chelating ability, and the antioxidant activity shows a certain dose effect, but the antioxidant activity of FLEO is the weakest among the four oils. Meanwhile, under the stress of hydrogen peroxide, CEO demonstrated a significant antioxidant protective effect on cells. It is worth mentioning that compared with the positive control, the FREO exhibited a better antibacterial rate. When the concentration of essential oil is 20 mg/mL, the bacteriostatic rate can reach 100%. Therefore, it could be a promising candidate among medicinal and edible plants.

Secondary Metabolites of Endophytes Associated with the Zingiberaceae Family and Their Pharmacological Activities

Zingiberaceae is commonly known as the ginger family and has been extensively studied in the last decades for its pharmacological purposes. The study of ginger includes microorganisms known as endophytes, which raise interest for the research community because they can produce a wide range of secondary metabolites. This review discusses the secondary metabolites of endophytes from the Zingiberaceae family and their pharmacological activities. We detail the group of secondary metabolites, updated for its absolute structures, source and part origins, and, especially, pharmacological divided properties. Zingiberaceae endophytes have 106 volatile compounds and 52 isolated constituents, including 17 polyketides, five nonribosomal peptides, five aromatic compounds, three alkaloids, and 21 terpene-alkaloids. They have antimicrobial, anticancer, antioxidant, and anti-inflammatory activities. Secondary metabolites from plant endophytes of the Zingiberaceae family have the potential to be therapeutic drugs in the future. Research on endophytic bacteria or fungi has been little performed. Therefore, this study supports a new drug discovery from Zingiberaceae endophytes and compares them for future drug development.

In Vitro Anti-Inflammatory Activity of Essential Oil and β-Bisabolol Derived from Cotton Gin Trash

Natural α-bisabolol has been widely used in cosmetics and is sourced mainly from the stems of Candeia trees that have become endangered due to over exploitation. The in vitro anti-inflammatory activity of cotton gin trash (CGT) essential oil and the major terpenoid (β-bisabolol) purified from the oil were investigated against lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages as well as the 3t3 and HS27 fibroblast cell lines. Nitric oxide (NO), prostaglandin E₂ (PGE₂), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) were measured using Greiss reagent, enzyme-linked immunosorbent assay (ELISA), and cytokine bead array (CBA)-flow cytometry. Non-toxic concentrations of CGT oil and β-bisabolol (1.6–50.0 µg/mL) significantly inhibited the production of the inflammatory mediators in a dose-dependent manner. Maximal inhibition by β-bisabolol was 55.5% for NO, 62.3% for PGE₂, and 45.3% for TNF-α production in RAW cells. β-Bisabolol induced a level of inhibition similar to an equal concentration of α-bisabolol (50.0 µg/mL), a known anti-inflammatory agent. These results suggest β-bisabolol exerts similar in vitro effects to known topical anti-inflammatory agents and could therefore be exploited for cosmetic and therapeutic uses. This is the first study to report the in vitro anti-inflammatory activity of β-bisabolol in CGT essential oil.

Pharmacological and Therapeutic Potential of Myristicin: A Literature Review

Natural products have been used by humanity for many centuries to treat various illnesses and with the advancement of technology, it became possible to isolate the substances responsible for the beneficial effects of these products, as well as to understand their mechanisms. In this context, myristicin, a substance of natural origin, has shown several promising activities in a large number of in vitro and in vivo studies carried out. This molecule is found in plants such as nutmeg, parsley, carrots, peppers, and several species endemic to the Asian continent. The purpose of this review article is to discuss data published in the last 10 years at Pubmed, Lilacs and Scielo databases, reporting beneficial effects, toxicity and promising data of myristicin for its future use in medicine. From 94 articles found in the literature, 68 were included. Exclusion criteria took into account articles whose tested extracts did not have myristicin as one of the major compounds.

Mint Oils: In Vitro Ability to Perform Anti-Inflammatory, Antioxidant, and Antimicrobial Activities and to Enhance Intestinal Barrier Integrity

The objectives of the study were to test the biological activities of peppermint and spearmint oils via (i) measuring in vitro anti-inflammatory effects with porcine alveolar macrophages (PAMs), (ii) determining the barrier integrity of IPEC-J2 by analyzing transepithelial electrical resistance (TEER), (iii) testing their antioxidant activities, and (iv) investigating the antimicrobial activity against enterotoxigenic Escherichia coli (ETEC) F18+. Briefly, (i) macrophages were seeded at 10⁶ cells/mL and treated (24 h) with mint oils and lipopolysaccharide (LPS). The treatments were 2 (0 or 1 μg/mL of LPS) × 5 (0, 25, 50, 100, 200 µg/mL of mint oils). The supernatants were collected for TNF-α and IL-1β measurement by ELISA; (ii) IPEC-J2 cells were seeded at 5 × 10⁵ cells/mL and treated with mint oils (0, 25, 50, 100, and 200 μg/mL). TEER (Ωcm²) was measured at 0, 24, 48, and 72 h; (iii) the antioxidant activity was assessed (0, 1, 50, 100, 200, 500, and 600 mg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power assays; (iv) overnight-grown ETEC F18+ were quantified (CFU/mL) after supplementing with peppermint and spearmint oils (0, 1.44, 2.87, 5.75, 11.50, and 23.00 mg/mL). All data were analyzed using the MIXED procedure. Both mint oils significantly inhibited (p < 0.05) IL-1β and TNF-α secretion from LPS-stimulated PAMs. Mint oil treatments did not affect TEER in IPEC-J2. Spearmint and peppermint oils exhibited (p < 0.05) strong antioxidant activities in DPPH and reducing power assays. Both mint oils also dose-dependently inhibited (p < 0.05) the growth of ETEC F18+ in vitro. The results of the study indicated that both mint oils are great candidate feed additives due to their in vitro anti-inflammatory, antioxidant, and antimicrobial effects. Further research is needed to evaluate their efficacy in vivo.

Effect of p-cymene and rosmarinic acid on gastric ulcer healing - Involvement of multiple endogenous curative mechanisms

BACKGROUND

p-Cymene and rosmarinic acid are secondary metabolites found in several medicinal plants and spices. Previous studies have demonstrated their anti-inflammatory, antioxidant, and cytoprotective effects.

PURPOSE

To evaluate their gastroduodenal antiulcer activity, gastric healing and toxicity in experimental models.

METHODS

Preventive antiulcer effects were assessed using oral pre-treatment on HCl/ethanol-induced gastric lesions and cysteamine-induced duodenal lesions models. Gastric healing, the underlining mechanisms and toxicity after repeated doses were carried out using the acetic acid-induced gastric ulcer rat model and oral treatment for 14 days.

RESULTS

In the HCl/ethanol-induced gastric ulcer and cysteamine-induced duodenal injury, p-cymene and rosmarinic acid (50-200 mg/kg) decreased significantly the ulcer area, and so prevented lesions formation. In the acetic acid-induced ulcer model, both compounds (200 mg/kg) markedly reduced the ulcerative injury. These effects were related to an increase in the levels of reduced glutathione (GSH) and interleukin (IL)-10, and due to a decrease in malondialdehyde (MDA), IL-1β, tumor necrosis factor (TNF)-α, total and mitochondrial reactive oxygen species (ROS) levels. Downregulation of factor nuclear kappa B (NFκB) and enhanced expression of suppressor of cytokine signaling (SOCS)3 were also demonstrated. Furthermore, positive vascular endothelial growth factor (VEGF), metalloproteinase (MMP)-2, and cyclooxygenase (COX-2)-stained cells were increased in treated groups. Treatment also upregulated the platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-β and epidermal growth factor receptor (EGFR) in gastric tissues. In isolated gastric epithelial cells this healing effect seems to be linked to a modulation of apoptosis, proliferation, survival and protein phosphorylation, such as the extracellular signal-regulated kinases (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK). Oral toxicity investigation for 14 days revealed no alterations in heart, liver, spleen, and kidneys weight nor the biochemical and hematological assessed parameters. p-Cymene and rosmarinic acid also protected animals from body weight loss maintaining feed and water intake.

CONCLUSIONS

Data altogether suggest low toxicity, antiulcer and gastric healing activities of p-cymene and rosmarinic acid. Antioxidant and immunomodulatory properties seem to be involved in the curative effect as well as the induction of different factors linked to tissue repair.

Antioxidant, Antimicrobial and Anti-Inflammatory Activities of Essential Oil Derived from the Wild Rhizome of Atractylodes macrocephala

The present study investigated the chemical composition, antioxidant, antimicrobial, and anti-inflammatory activities of essential oil (EO) derived from the wild rhizomes of Atractylodes macrocephala Koidz. (AMA) growing in Qimen County (eastern China). GC/MS analysis identified fifteen compounds, representing 92.55 % of AMA EO. The major compounds were atractylone (39.22 %), β-eudesmol (27.70 %), thymol (5.74 %), hinesol (5.50 %), and 11-isopropylidenetricyclo[4.3.1.1(2,5)]undec-3-en-10-one (4.71 %). Ferricyanide reducing, 1,1-diphenyl-2-picyrlhydrazyl (DPPH) and 3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) scavenging assays revealed that AMA EO exhibited strong antioxidant capacities. Additionally, AMA EO showed inhibitory effects on growth of Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, and Bacillus subtilis, with the minimum inhibitory concentrations (MIC) ranging from 0.5 to 2.0 mg/mL. Treatments with AMA EO also significantly inhibited nitric oxide (NO) and prostaglandin E₂ (PGE₂ ) production in lipopolysaccharide-stimulated RAW264.7 cells, indicating anti-inflammatory activity of AMA EO. Furthermore, treatments with AMA EO decreased the transcriptional levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which might be the molecular mechanisms underlying its anti-inflammatory effects. Overall, these results provide a theoretical basis for further study and application of AMA EO in food and medicine products.

Mechanisms Underlying the Anti-Inflammatory Activity of Bergamot Essential Oil and Its Antinociceptive Effects

Renewed interest in natural products as potential source of drugs led us to investigate on both the anti-inflammatory and anti-nociceptive activity of Citrus bergamia Risso et Poiteau (bergamot) essential oil (BEO). Carrageenan-induced paw edema in rats was used as an experimental model of inflammation. Because of the toxicity of furocoumarins, we performed our study by using the BEO fraction deprived of these compounds (BEO-FF). Treatment with BEO-FF led to a significant inhibition of paw edema induced by a sub-plantar injection of carrageenan. Moreover, histological examination of BEO-FF-treated rat paw biopsies showed a reduction of pathological changes typical of edema. Pre-treatment with BEO-FF significantly reduced interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α levels in the paw homogenates, as well as nitrite/nitrate and prostaglandin E₂ (PGE₂) content in exudates. In addition, BEO-FF possesses antioxidant properties, as determined by cell-free assays. Furthermore, results of the writhing test showed that BEO-FF elicited a pronounced analgesic response, as demonstrated by a significant inhibition of constrictions in mice receiving acetic acid, with respect to control animals, whereas the results of the hot plate test suggested that the supra-spinal analgesia participates in the anti-nociceptive effect of BEO-FF. Our study indicates that BEO-FF exerts anti-inflammatory and anti-nociceptive effects, and suggests its potential role as an anti-edemigen and analgesic drug.

Antimicrobial, Antioxidant, and Immunomodulatory Properties of Essential Oils: A Systematic Review

Essential oils (EOs) are a mixture of natural, volatile, and aromatic compounds obtained from plants. In recent years, several studies have shown that some of their benefits can be attributed to their antimicrobial, antioxidant, anti-inflammatory, and also immunomodulatory properties. Therefore, EOs have been proposed as a natural alternative to antibiotics or for use in combination with antibiotics against multidrug-resistant bacteria in animal feed and food preservation. Most of the results come from in vitro and in vivo studies; however, very little is known about their use in clinical studies. A systematic and comprehensive literature search was conducted in PubMed, Embase®, and Scopus from December 2014 to April 2019 using different combinations of the following keywords: essential oils, volatile oils, antimicrobial, antioxidant, immunomodulation, and microbiota. Some EOs have demonstrated their efficacy against several foodborne pathogens in vitro and model food systems; namely, the inhibition of S. aureus, V. cholerae, and C. albicans has been observed. EOs have shown remarkable antioxidant activities when used at a dose range of 0.01 to 10 mg/mL in cell models, which can be attributed to their richness in phenolic compounds. Moreover, selected EOs exhibit immunomodulatory activities that have been mainly attributed to their ability to modify the secretion of cytokines.

Study of the anti-allergic and anti-inflammatory activity of Brachychiton rupestris and Brachychiton discolor leaves (Malvaceae) using in vitro models

Background

Brachychiton rupestris and Brachychiton discolor (Malvaceae) are ornamental trees native to Australia. Some members of Brachychiton and its highly related genus, Sterculia, are employed in traditional medicine for itching, dermatitis and other skin diseases. However, scientific studies on these two genera are scarce. Aiming to reveal the scientific basis of the folk medicinal use of these plants, the cytotoxicity, anti-inflammatory and anti-allergic activities of Brachychiton rupestris and Brachychiton discolor leaves extracts and fractions were evaluated. Also, phytochemical investigation of B. rupestris was performed to identify the compounds exerting the biological effect.

Methods

Extracts as well as fractions of Brachychiton rupestris and Brachychiton discolor were tested for their cytotoxicity versus hepatoma HepG2, lung A549, and breast MDA-MB-231 cancer cell lines. Assessment of the anti-allergic activity was done using degranulation assay in RBL-2H3 mast cells. Anti-inflammatory effect was tested by measuring the suppression of superoxide anion production as well as elastase release in fMLF/CB-induced human neutrophils. Phytochemical investigation of the n-hexane, dichloromethane and ethyl acetate fractions of B. rupestris was done using different chromatographic and spectroscopic techniques.

Results

The tested samples showed no cytotoxicity towards the tested cell lines. The nonpolar fractions of both B. rupestris and B. discolor showed potent anti-allergic potency by inhibiting the release of β-hexosaminidase. The dichloromethane fraction of both species exhibited the highest anti-inflammatory activity by suppressing superoxide anion generation and elastase release with IC₅₀ values of 2.99 and 1.98 μg/mL, respectively for B. rupestris, and 0.78 and 1.57 μg/mL, respectively for B. discolor. Phytochemical investigation of various fractions of B. rupestris resulted in the isolation of β-amyrin acetate (1), β-sitosterol (2) and stigmasterol (3) from the n-hexane fraction. Scopoletin (4) and β-sitosterol-3-O-β-D-glucoside (5) were obtained from the dichloromethane fraction. Dihydrodehydrodiconiferyl alcohol 4-O-β-D-glucoside (6) and dihydrodehydrodiconiferyl alcohol 9-O-β-D-glucoside (7) were separated from the ethyl acetate fraction. Scopoletin (4) showed anti-allergic and anti-inflammatory activity.

Conclusions

It was concluded that the nonpolar fractions of both Brachychiton species exhibited anti-allergic and anti-inflammatory activities.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2359-6) contains supplementary material, which is available to authorized users.

Anti-inflammation effects of 8-oxo-9-octadecenoic acid isolated from Undaria peterseniana in lipopolysaccharide-stimulated macrophage cells

The aim of this study was to investigate the anti-inflammatory activity of 8-oxo-9-octadecenoic acid (OOA) isolated from Undaria peterseniana by examining its ability to inhibit the lipopolysaccharide (LPS)-induced production of inflammatory mediators in RAW 264.7 macrophage cells. We found that OOA significantly suppressed the LPS-induced production of nitric oxide (NO) and inflammatory cytokines. OOA downregulated the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins. With respect to proinflammatory signaling pathways, OOA inhibited LPS-induced mitogen-activated protein kinase signaling by inhibiting the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). Moreover, OOA inhibited LPS-induced nuclear factor (NF)-κB signaling by reducing the phosphorylation of IκB-α and p50 proteins. These results indicate that OOA significantly reduces proinflammatory signaling, which results in reduced expression of cytokines and proinflammatory mediators. Taken together, these results suggest that OOA has potent anti-inflammatory effects and could be considered an effective anti-inflammatory agent.

Selected essential oils inhibit key physiological enzymes and possess intracellular and extracellular antimelanogenic properties in vitro

Essential oils (EOs) extracted from six medicinal herbs and food plants [Cinnamomum zeylanicum (CZ), Psiadia arguta (PA), Psiadia terebinthina (PT), Citrus grandis (CGp), Citrus hystrix (CH), and Citrus reticulata (CR)] were studied for any inhibitory potential against key physiological enzymes involved in diabetes (α-glucosidase), skin aging (collagenase and elastase), and neurodegenerative disorders (acetylcholinesterase). Kinetic studies of the active EOs on the aforementioned enzymes were determined using Lineweaver–Burk plots. The intracellular and extracellular antimelanogenic potential of the EOs were evaluated on B16F10 mouse melanocytes. CH and CR were found to significantly inhibit (2.476 ± 0.13 μg/mL and 3.636 ± 0.10 μg/mL, respectively) acetylcholinesterase, compared with galantamine (3.989 ± 0.16 μg/mL). CH inhibited collagenase (50% inhibitory concentration 28.71 ± 0.16 μg/mL) compared with the control (24.45 ± 0.19 μg/mL). The percentage inhibition in the elastase assay of CH was 63.21% compared to the positive control (75.09%). In addition, CH, CR, CGp, CZ, and PT were found to significantly inhibit α-glucosidase (276.70 ± 0.73 μg/mL, 169.90 ± 0.58 μg/mL, 240.60 ± 6.50 μg/mL, 64.52 ± 0.69 μg/mL, and 313.0 ± 5.0 μg/mL, respectively), compared to acarbose (448.80 ± 0.81 μg/mL). Active EOs showed both uncompetitive and competitive types of inhibition. The EOs also inhibited intracellular (50% inhibitory concentration 15.92 ± 1.06 μg/mL, 23.75 ± 4.47 μg/mL, and 28.99 ± 5.70 μg/mL for CH, CR, and CGp, respectively) and extracellular (< 15.625 μg/mL for CH, CR, CGp, and PT) melanin production when tested against B16F10 mouse melanocytes. Results from the present study tend to show that EOs extracted from these medicinal plants can inhibit key enzymes and may be potential candidates for cosmetic and pharmaceutical industries.

Monoterpene esters and aporphine alkaloids from Illigera aromatica with inhibitory effects against cholinesterase and NO production in LPS-stimulated RAW264.7 macrophages

Three new monoterpene phenylpropionic acid esters, illigerates A-C (1-3), and one new aporphine alkaloid, illigeranine (4), as well as four known ones, actinodaphnine (5), nordicentrine (6), 8-hydroxy carvacrol (7), and 3-hydroxy-α,4-dimethyl styrene (8), were isolated from the tubers of Illigera aromatica. The structures of 1-4 were identified by HRESIMS, 1D and 2D NMR, and electronic circular dichroism spectra. Compound 1 potently inhibited NO production in LPS-stimulated RAW264.7 cells with an IC₅₀ value of 18.71 ± 0.85 μM; compound 1, 3, and 4 showed moderate butyrylcholinesterase inhibitory activities with the IC₅₀ values of 46.86 ± 0.65, 53.51 ± 0.71, and 31.62 ± 1.15 μM, respectively. Compound 4 showed weak AChE inhibitory activity with an IC₅₀ value of 81.69 ± 2.07 μM, and compounds 5 and 6 possessed moderate AChE inhibitory activities with the IC₅₀ values of 47.74 ± 1.66 and 40.28 ± 2.73 μM, respectively. This paper provides a chemical structure and bioactive foundation for using I. aromatica as an herbal medicine.