Ocotea quixos Lam. essential oil: in vitro and in vivo investigation on its anti-inflammatory properties

Therapeutic Applications of Essential Oils from Native and Cultivated Ecuadorian Plants: Cutaneous Candidiasis and Dermal Anti-Inflammatory Activity

Essential oils are a complex mixture of aromatic substances whose pharmacological actions, including antimicrobial, antioxidant, anticancer, and anti-inflammatory activities, have been widely reported. This study aimed to evaluate the anti-Candida and dermal anti-inflammatory activity of essential oils from native and cultivated Ecuadorian plants. Essential oils from Bursera graveolens, Dacryodes peruviana, Mespilodaphne quixos, and Melaleuca armillaris were isolated by hydrodistillation and were characterized physically and chemically. Its tolerance was analyzed by in vitro and in vivo studies. The antifungal activity was studied against Candida albicans, Candida glabrata, and Candida parapsilosis, whereas the anti-inflammatory effect was evaluated by a mouse ear edema model. The main compounds were limonene, α-phellandrene, (E)-methyl cinnamate, and 1,8-cineole, respectively. All essential oils showed high tolerability for skin application, antifungal activity against the three Candida strains, and anti-inflammatory efficacy by decreasing edema and overexpression of pro-inflammatory cytokines. Dacryodes peruviana essential oil showed the highest antifungal activity. On the other hand, Dacryodes peruviana and Melaleuca armillaris showed the greatest anti-inflammatory potential, decreasing edema by 53.3% and 65.25%, respectively, and inhibiting the overexpression of TNF-α, IL-8, IL-17A, and IL-23. The results suggest that these essential oils could be used as alternative therapies in the treatment of both cutaneous candidiasis and dermal inflammation.

The Effect of an Essential Oil Blend on Growth Performance, Intestinal Health, and Microbiota in Early-Weaned Piglets

Essential oils (EO) are promising feed additives for their antibacterial, antioxidant, and immune-enhancing abilities with low toxicity. Carvacrol, thymol, and cinnamaldehyde are commonly used to synthesize EO. However, few studies focus on combining these three EO in early-weaned piglets. In the present study, 24 piglets weaned at 21 d of age were randomly divided into 2 groups (6 replicate pens per group, 2 piglets per pen). The piglets were fed a basal diet (the control group) and a basal diet supplemented with 400 mg/kg EO (a blend consisting of carvacrol, thymol, and cinnamaldehyde, the EO group) for 28 days. At the end of the experiment, one piglet per pen was randomly chosen to be sacrificed. Growth performance, hematology, plasma biochemical indices, antioxidant capacity, intestinal epithelial development and immunity, colonic volatile fatty acids (VFA), and microbiota were determined. The results indicated that the diet supplemented with EO significantly improved average daily feed intake (ADFI, p < 0.01) and average daily gain (ADG, p < 0.05) in the day 0 to 28 period. EO supplementation led to a significant decrease in plasma lysozyme (p < 0.05) and cortisol levels (p < 0.01). Additionally, EO significantly promoted jejunal goblet cells in the villus, jejunal mucosa ZO-1 mRNA expression, ileal villus height, and ileal villus height/crypt depth ratio in piglets (p < 0.05). The ileal mucosal TLR4 and NFκB p-p65/p65 protein expression were significantly inhibited in the EO group (p < 0.05). Colonic digesta microbiota analysis revealed that bacteria involving the Erysipelotrichaceae family, Holdemanella genus, Phascolarctobacterium genus, and Vibrio genus were enriched in the EO group. In conclusion, these findings indicate that the EO blend improves ADG and ADFI in the day 0 to 28 period, as well as intestinal epithelial development and intestinal immunity in early-weaned piglets, which provides a theoretical basis for the combined use of EO in weaned piglets.

Essential Oils of Gardenia jasminoides J. Ellis and Gardenia jasminoides f. longicarpa Z.W. Xie & M. Okada Flowers: Chemical Characterization and Assessment of Anti-Inflammatory Effects in Alveolar Macrophage

Alveolar macrophage is the predominant cell type in the lung and is thought to be the major target for anti-inflammatory therapy in chronic obstructive pulmonary disease (COPD). Aromatherapy using natural essential oils with anti-inflammatory effects for inhalable administration is a potential complementary and alternative therapy for COPD treatment. The Gardenia jasminoides flower is famous for its fragrance in East Asia and is used for treating colds and lung problems in folk medicine. Therefore, in the present study, flower essential oils from two main medicinal gardenia varieties (G. jasminoides J. Ellis and G. jasminoides f. longicarpa Z.W. Xie & M. Okada) were extracted by hydro-distillation, and their chemical components were analyzed by GC-MS. The anti-inflammatory effects of the two essential oils and their main ingredients were further studied on lipopolysaccharide (LPS)-induced models in murine alveolar macrophages (MH-S). The results indicated that the chemical constituents of the two gardenia varieties were quite different. Alcohol accounted for 53.8% of the G. jasminoides essential oil, followed by terpenes (16.01%). Terpenes accounted for 34.32% of the G. jasminoides f. longicarpa essential oil, followed by alcohols (19.6%) and esters (13.85%). Both the two gardenia essential oils inhibited the LPS-induced nitric oxide (NO) release and reduced the production of tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2) in the MH-S cells. Linalool and α-farnesene dose-dependently reduced the NO release in the MH-S cells. Linalool and α-farnesene did not affect the PGE2 production but regulated the expression of TNF- α. In addition to linalool and α-farnesene, other components in the gardenia flower essential oils appeared to be able to act as anti-inflammatory agents and influence the PGE2 pathway.

Essential oils from Ocotea species: Chemical variety, biological activities and geographic availability

This review describes the chemical composition and biological properties of essential oils from plants of the Ocotea genus, from different origin. This taxon belongs to the Laureaceae family, which in turn, is best known for medicinal use, often related to the essential oils. The text includes studies about Ocotea species distributed mainly on the South American continent, but also reporting species located in North America and Africa. Brazil, Colombia, Costa Rica and Ecuador are countries with highest number of species mentioned in the review. Also, the major components of each essential oil, its chemical structures, as well as the description and extent of biological activities related to essential oils are detailed in this review. Finally, the text discusses the chemical and biological aspects of these studies in a comparatively way, also informing additional data such as yield, biome of origin and pharmacobotanical location.

Chemical and Enantioselective Analysis of the Essential Oils from Different Morphological Structures of Ocotea quixos (Lam.) Kosterm

The traditional Ecuadorian spice Ishpingo, characterized by a strong cinnamon-like aroma, is constituted by the dry cupules of Amazonian species Ocotea quixos. Nevertheless, bark and leaves also present aromatic properties and are sometimes used as substitutes. In the present study, the essential oils, distilled from these morphological structures, are comparatively analyzed for their chemical and enantiomeric compositions. A total of 88 components were identified with 2 orthogonal GC columns, whereas 79, corresponding to more than 94%, were also quantified with at least 1 column. Major compounds were (E)-methyl cinnamate in cupules (35.9-34.2%), (E)-cinnamaldehyde in bark (44.7-47.0%), and (E)-cinnamyl acetate (46.0-50.4%) in leaves. For what concerns the enantioselective analysis, 10 chiral terpenes and terpenoids were detected, of which 6 were present as enantiomeric pairs in at least 1 essential oil, the others being enantiomerically pure. Both quantitative and enantioselective analyses were submitted to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), where their results confirmed significative difference among the three products.

Ocotea nutans (Nees) Mez: structural elucidation of C-hetorosides flavonoids and evaluation of their antioxidant and antibacterial properties from ethyl acetate extract

The Ocotea genus exhibits a variety of pharmacological, antibacterial and antioxidant effects. The aim of the present study was to evaluate the antioxidant potential and antibacterial properties of the ethyl acetate fraction of Ocotea nutans leaves. Isolation and identification of the phenolic compounds from the fraction was also carried out. The isolated compounds were characterised by one- and two-dimensional nuclear magnetic resonance analysis and identified as vitexin (1) and isovitexin (2). The ethyl acetate fraction of Ocotea nutans leaves demonstrated considerable antioxidant potential. The observed minimum inhibitory concentration of 250 µg.mL^-1 was classified as a moderate antibacterial activity against Enterococcus faecalis. Findings from this study demonstrate the utility of this plant as a potential source of antioxidant and antibacterial agents.

Anti-mycobacterial and immunomodulatory activity of n-hexane fraction and spathulenol from Ocotea notata leaves

Abstract Ocotea notata (Lauraceae) is popularly known as white-cinnamon. Ocotea species have several medicinal uses, especially for treating chest pain, rheumatism and wounds. The present study aimed to analyze the chemical composition of O. notata n-hexane fraction, in addition to its anti-mycobacterial and immunomodulatory activities. The n-hexane fraction was analyzed by GC-MS and was chromatographed to afford 15 subfractions (SF1-15), where SF5 was identified, by GC-MS and NMR, as the sesquiterpene spathulenol. The n-hexane fraction was the most potent in inhibiting nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) production on LPS-stimulated macrophages (IC50 8.3 ± 0.9 and 5.9 ±1.0 μg/mL, respectively). SF4, a major subfraction, that presents a spathulenol analogous as a constituent, also inhibited NO and TNF-α production. Spathulenol only modulated NO production (IC50 45.6 ± 1.4 μg/mL). The n-hexane fraction, SF4, and spathulenol revealed antimycobacterial activity against Mycobacterium bovis BCG, M. tuberculosis H37Rv, and M299 strains. Spathulenol inhibited the growth of Mtb H37Rv with MIC50 36.9 ± 1.5 μg/mL (167.5 ± 6.8 μM), and Mtb M299 with MIC5042.1 ± 0.5 μg/mL (191.0 ± 2.2 μM). This is the first report describing the isolation of spathulenol from O. notata leaves and its anti-mycobacterial activity.

Rapid structural characterisation of benzylisoquinoline and aporphine alkaloids from Ocotea spixiana acaricide extract by HPTLC-DESI-MSn

INTRODUCTION

Lauraceae alkaloids are a structurally diverse class of plant specialised secondary metabolites that play an important role in modern pharmacotherapy, being useful as well as model compounds for the development of synthetic analogues. However, alkaloids characterisation is challenging due to low concentrations, the complexity of plant extracts, and long processes for accurate structural determinations.

OBJECTIVE

The use of high-performance thin layer chromatography coupled with desorption electrospray ionisation multistage mass spectrometry (HPTLC DESI-MSⁿ ) as a fast tool to identify alkaloids present in Ocotea spixiana extract and evaluate the extract's acaricide activity.

METHODS

Ocotea spixiana twigs were extracted by conventional liquid-liquid partitioning. HPTLC analysis of the ethyl acetate extract was performed to separate isobaric alkaloids prior to DESI-MSⁿ analysis, performed from MS³ up to MS⁷ . The extract's acaricide activity against Rhipicephalus microplus was evaluated by in vitro (larval immersion test) and in silico tests.

RESULTS

HPTLC-DESI-MSⁿ analysis was performed to identify a total of 13 aporphine and four benzylisoquinoline-type alkaloids reported for the first time in O. spixiana. In vitro evaluation of the extract and the alkaloid boldine showed significant activity against R. microplus larvae. It was established in silico that boldine had important intermolecular interactions with R. microplus acetylcholinesterase enzyme.

CONCLUSION

The present study demonstrated that HPTLC-DESI-MSⁿ is a useful analytical tool to identify isoquinoline alkaloids in plant extracts. The acaricide activity of the O. spixiana ethyl acetate extract can be correlated to the presence of alkaloids.

Dehydrodieugenol B and hexane extract from Endlicheria paniculata regulate inflammation, angiogenesis, and collagen deposition induced by a murine sponge model

The present study reports the evaluation of hexane extract from Endlicheria paniculata and its main metabolite dehydrodieugenol B in the inflammatory response induced by a murine implant sponge model. As a result, a reduction in the inflammatory markers (myeloperoxidase and N-acetyl-β-D-glucosaminidase) and number of mast cells were observed in comparison to the control group. All doses were also able to reduce angiogenic parameters evaluated in fibrovascular tissue. In implants treated with dehydrodieugenol B a reduction in total collagen deposition and types I and III collagen fibers were observed, while an increased in total collagen deposition and types I and III collagen fibers were observed in the treatment with hexane extract. Docking studies into cyclooxygenase-2 active site revealed that the dehydrodieugenol B had binding modes and energies comparable with celecoxib, diclofenac and ibuprofen. Therefore, dehydrodieugenol B was able to alter key components of chronic inflammation, resulting in a reduced inflammatory response and also presenting antifibrogenic and antiangiogenic effects. However, treatment with hexane extract resulted in a reduced inflammatory response with antiangiogenic effects, but caused fibrogenic effects.

Acetylcholinesterase inhibitory activities and bioguided fractionation of the Ocotea percoriacea extracts: HPLC-DAD-MS/MS characterization and molecular modeling of their alkaloids in the active fraction

In vitro acetylcholinesterase activities of the hexane, dichloromethane, ethyl acetate, n-butanol and aqueous extracts of leaves of Ocotea percoriacea Kosterm. (Lauraceae) were evaluated. The bioguided fractionation of the most active extract (dichloromethane) using silica gel open-column chromatography led to an active alkaloidal fraction composed of isocorydine N-oxide, isocorydine N-oxide derivative, palmatine, roemerine and roemerine N-Oxide. The identification of the chemical structure of these compounds was carried out with high-performance liquid chromatography coupled to electrospray ionization multiple-stage mass spectrometry (HPLC-ESI-MS/MS). Aiming to understand their inhibitory activities, these alkaloids were docked into a 3D model of Electrophorus electricus Acetylcholinesterase (EelAChE) built in the Modeller 9.18 employing homology modeling approach. The results suggest that the alkaloids had the same binding mode and, possibly, the inhibition mechanism of classic drugs (ex. tacrine and donepezil). The structural difference of these compounds opens a new opportunity for the optimization of leading compounds.

Chemical Diversity, Biological Activity, and Genetic Aspects of Three Ocotea Species from the Amazon

Ocotea species present economic importance and biological activities attributed to their essential oils (EOs) and extracts. For this reason, various strategies have been developed for their conservation. The chemical compositions of the essential oils and matK DNA sequences of O. caudata, O. cujumary, and O. caniculata were subjected to comparison with data from O. floribunda, O. veraguensis, and O. whitei, previously reported. The multivariate analysis of chemical composition classified the EOs into two main clusters. Group I was characterized by the presence of α-pinene (9.8-22.5%) and β-pinene (9.7-21.3%) and it includes O. caudata, O. whitei, and O. floribunda. In group II, the oils of O. cujumary and O. caniculata showed high similarity due amounts of β-caryophyllene (22.2% and 18.9%, respectively). The EO of O. veraguensis, rich in p-cymene (19.8%), showed minor similarity among all samples. The oils displayed promising antimicrobial and cytotoxic activities against Escherichia coli (minimum inhibitory concentration (MIC) < 19.5 µg·mL^-1) and MCF-7 cells (median inhibitory concentration (IC₅₀) ≅ 65.0 µg·mL^-1), respectively. The analysis of matK gene displayed a good correlation with the main class of chemical compounds present in the EOs. However, the matK gene data did not show correlation with specific compounds.

Antispasmodic and myorelaxant effects of the flavoring agent methyl cinnamate in gut: potential inhibition of tyrosine kinase

Methyl cinnamate (MC) is a safe flavoring agent useful to food industry. Although chemically analog to tyrosine kinase inhibitors, there is little information regarding its biological actions. Here, we aimed at assessing the MC effects on gastrointestinal contractility and the putative involvement of tyrosine kinase in the mediation of these effects. Isometric contractions were recorded in rat isolated strips from stomach, duodenum and colon segments. In gastric strips, MC (3-3000 µM) showed antispasmodic effects against carbachol-induced contractions, which remained unchanged by either l-NAME or tetraethylammonium pretreatment and occurred with potency similar to that obtained against contractions evoked by potassium or U-46619. In colon strips, MC was four times more potent than in gastric ones. MC and the positive control genistein inhibited phasic contractions induced by acetylcholine in Ca2+-free medium, an effect fully prevented by sodium orthovanadate. Both MC and genistein decreased the spontaneous contractions of duodenal strips and shortened the time necessary for gastric fundic tissues to reach 50% of maximal relaxation. In freshly isolated colon myocytes, MC decreased the basal levels of cytoplasmic Ca2+, but not the potassium-elicited cytoplasmic Ca2+ elevation. Colon strips obtained from rats subjected to intracolonic acetic acid instillation showed reduced contractility to potassium, which was partially recovered in MC-treated rats. Inhibitory effect of nifedipine against cholinergic contractions, blunted in acetic acid-induced colitis, was also recovered in MC-treated rats. In conclusion, MC inhibited the gastrointestinal contractility with a probable involvement of tyrosine kinase pathways. In vivo, it was effective to prevent the deleterious effects of colitis resulting from acetic acid injury.

A review on anti-inflammatory activity of phenylpropanoids found in essential oils

The search for alternative drugs capable of disrupting the inflammatory process has become an important issue in scientific research, especially with reference to the use of natural substances and the reduction of undesirable side effects. Essential oils represent an important source of such substances, since their active constituents often exhibit an array of pharmacological properties, including anti-inflammatory activity. This review presents an overview of the anti-inflammatory action exerted by phenylpropanoids from essential oils and discusses possible mechanisms of action involved in the anti-inflammatory response, assessed through specific experimental models.