Potential anti-inflammatory biomarkers from Myrtaceae essential oils revealed by untargeted metabolomics

Many species from Myrtaceae have traditionally been used in traditional medicine as anti-inflammatory, antimicrobial, antidiarrheal, antioxidant and antirheumatic, besides in blood cholesterol reduction. In the present work, the anti-inflammatory activity of essential oils from eighteen Myrtaceae spp. were evaluated according to their ex-vivo anti-inflammatory activity in human blood, and the corresponding biomarkers were determined using untargeted metabolomics data and multivariate data analysis. From these studied species, six displayed anti-inflammatory activity with percentage rates of inhibition of PGE2 release above 70%. Caryophyllene oxide (1), humulene epoxide II (2), β-selinene (3), α-amorphene (4), α-selinene (5), germacrene A (6), β-bisabolene (7), α-muurolene (8), α-humulene (9), β-gurjunene (10), myrcene (11), β-elemene (12), α-cadinol (13), α-copaene (14), E-nerolidol (15) and ledol (16) were annotated as potential anti-inflammatory biomarkers. The results obtained in this study point to essential oils from species of the Myrtaceae family as a rich source of anti-inflammatory agents.

Essential Oils from Different Myrtaceae Species from Brazilian Atlantic Forest Biome - Chemical Dereplication and Evaluation of Antitrypanosomal Activity

Chagas Disease (CD), caused by flagellate protozoan Trypanosoma cruzi, is a Neglected Tropical Diseases (NTD) that affect approximately seven million people worldwide with a restrict therapeutical arsenal. In the present study, the essential oils from 18 Myrtaceae species were extracted, chemically dereplicated, and evaluated in vitro against T. cruzi. From these, eight essential oils were considered promising (IC₅₀ <10 μg/mL and SI>10) against the protozoan: Eugenia florida, E. acutata, E. widgrenii, Calyptranthes brasilienses, C. widgreniana, Plinia cauliflora, Campomanesia xanthocarpa, and Psidium guajava. Multivariate data analysis pointed out (E)-caryophyllene, α-humulene, limonene, caryophyllene oxide, and α-copaene playing an important role in the anti-T. cruzi activity. The obtained results demonstrated the potential of essential oils of Myrtaceae species as valuable sources of bioactive compounds against T. cruzi.

In vivo anti-inflammatory activity of Fabaceae species extracts screened by a new ex vivo assay using human whole blood

INTRODUCTION

Plants have been considered a promising source for discovering new compounds with pharmacological activities. The Fabaceae family comprises a large variety of species that produce substances with diverse therapeutic potential, including anti-inflammatory activity. The limitations of current anti-inflammatories generate the need to research new anti-inflammatory structures with higher efficacy as well as develop methods for screening multiple samples, reliably and ethically, to assess such therapeutic properties.

OBJECTIVE

Validate and apply a quantification method for prostaglandin E₂ (PGE₂ ) production from an ex vivo assay in human blood in order to screen anti-inflammatory activity present in many Fabaceae species extracts.

METHODS

Human blood was incubated with extracts from 47 Fabaceae species. After lipopolysaccharide (LPS)-induced inflammation, PGE₂ was quantified in the plasma by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The extracts that presented PGE₂ production inhibition were further assessed through in vivo assay and then chemically characterised through an analysis of ultra-performance liquid chromatography electrospray ionisation quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-QTOF-MS² ) data.

RESULTS

The new ex vivo anti-inflammatory assay showed that five out of the 47 Fabaceae species inhibited PGE₂ production. Results from an in vivo assay and the metabolic profile of the active extracts supported the anti-inflammatory potential of four species.

CONCLUSION

The quantification method for PGE₂ demonstrated fast, sensitive, precise, and accurate results. The new ex vivo anti-inflammatory assay comprised a great, reliable, and ethical approach for the screening of a large number of samples before an in vivo bioassay. Additionally, the four active extracts in both ex vivo and in vivo assays may be useful for the development of more efficient anti-inflammatory drugs.

Soluble Fas ligand (sFasL) as a predictor of reduction of general psychopathology in schizophrenia after antipsychotic treatment

Introduction

Dysregulation of the apoptotic process is associated with the etiopathogenesis of schizophrenia, which is observed at the brain and peripheral blood levels. A significant negative correlation between the duration of the disease and serum sFasL concentration was demonstrated by other authors. It was shown that an increased rate of apoptosis is more pronounced in neuroleptic-free patients with the first-episode of schizophrenia than in patients with chronic disease.

Aim

Search for a predictor of good response to antipsychotic treatment based on the analysis of the sFasL plasma level and its relationship with clinical symptoms.

Methods

Fifty-three patients with chronic schizophrenia and 46 healthy individuals were enrolled in the study. The concentration of sFasL was measured by ELISA. Clinical assessments (PANSS, SANS, SAPS) and blood analyses were conducted three times: during the active phase of disease (at admission), after 4 weeks of pharmacotherapy, and after reaching remission.

Results

In the schizophrenia group, non-altered levels of sFasL (P = 0.1; U Mann-Whitney test), compared to the control, were detected at admission. The initial level of sFasL correlated negatively (r = −0.33; P = 0.04; Spearman's rank) with blood leukocyte count. Despite clinical improvement, no significant changes in the level of sFasL were observed. However, the sFasL level correlated negatively with the PANSS general psychopathology reduction after 4 weeks of pharmacotherapy (r = −0.7; P = 0.04) and after remission (r = −0.39; P = 0.026).

Conclusions

The results indicate a possible role of sFasL in apoptosis of blood leukocytes and suggest that the reduction of sFasL level can predict level of PANSS general psychopathology after antipsychotic treatment in schizophrenia.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Selected metabolites of kynurenine pathway and response to antipsychotic treatment in schizophrenia

Introduction

Deficit of glutamatergic transmission and aberrant function of kynurenine pathway, with disturbed synthesis of glutamate receptors antagonist, kynurenic acid (KYNA) and neurotoxic metabolite of kynurenine, 3-hydroxykynurenine (3-OH-KYN) have been implicated in the pathogenesis of schizophrenia.

Objectives

Demonstrated by others higher level of KYNA in the brain may cause relative deficiency of glutamate-mediate transmission with resulting behavioural and cognitive changes.

Aims

Search for predictors of satisfactory response to antipsychotic treatment based on the analysis of KYNA and 3-OH-KYN serum levels.

Methods

Fifty-three patients with chronic schizophrenia and 46 healthy individuals were enrolled in the study. Quantitative analyses of KYNA and 3-OH-KYN were performed using high-pressure liquid chromatography (HPLC) and electrochemical detection, respectively. Clinical assessments (PANSS, SANS, SAPS) and blood analyses were conducted at 3 time-points: during the active phase of disease, after 4 weeks of modified pharmacotherapy, and after reaching remission.

Results

In schizophrenia group, lower levels of KYNA (P = 0.002) and non-altered levels of 3-OH-KYN (p = 0.195), as compared to control, were detected during active phase of disease. Despite clinical improvement, no significant changes in the level of studied metabolites were observed later on. The initial level of 3-OH-KYN correlated negatively (r = –0.368; Spearman's rank) with clinical improvement (negative symptoms) (P < 0.05).

Conclusions

1. The peripheral dysregulation of kynurenine pathway metabolites in chronic schizophrenia manifests as relative increase in the ratio between neurotoxic 3-OH-KYN and neuroprotective KYNA. 2. The higher serum level of 3-OH-KYN during relapse of schizophrenia seems to predict poor response to antipsychotic treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Assessing the Chemical Composition and Antimicrobial Activity of Essential Oils from Brazilian Plants-Eremanthus erythropappus (Asteraceae), Plectrantuns barbatus, and P. amboinicus (Lamiaceae)

The chemical composition and antimicrobial activity of essential oils obtained from three Brazilian plant species-leaves and branches of Eremanthus erythropappus (Asteraceae), leaves of Plectranthus barbatus, and leaves of P. amboinicus (Lamiaceae)-were determined. Analysis by GC/MS and determination of Kovats indexes both indicated δ-elemene (leaves-42.61% and branches-23.41%) as well as (-)-α-bisabolol (leaves-24.80% and stem bark-66.16%) as major constituents of E. erythropappus essential oils. The main components of leaves of P. barbatus were identified as (Z)-caryophyllene (17.98%), germacrene D (17.35%), and viridiflorol (14.13%); whereas those of leaves of P. amboinicus were characterized as p-cymene (12.01%), γ-terpinene (14.74%), carvacrol (37.70%), and (Z)-caryophyllene (14.07%). The antimicrobial activity against yeasts and bacteria was assessed in broth microdilution assays to determine the minimum inhibitory concentration (MIC) necessary to inhibit microbial growth. In addition, the crude oil of branches of E. erythropappus was subjected to chromatographic separation procedures to afford purified (-)-α-bisabolol. This compound displayed biological activity against pathogenic yeasts, thus suggesting that the antimicrobial effect observed with crude oils of E. erythropappus leaves and branches may be related to the occurrence of (-)-α-bisabolol as their main component. Our results showed that crude oils of Brazilian plants, specifically E. erythropappus, P. barbatus, and P. amboinicus and its components, could be used as a tool for the developing novel and more efficacious antimicrobial agents.