Phytochemical and sensorial characterization of Hyssopus officinalis subsp. aristatus (godr.) Nyman (Lamiaceae) by GC–MS, HPLC–UV–DAD, spectrophotometric assays and e-nose with aid of chemometric techniques

The impact of Hyssop (Hyssopus officinalis) extract on activation of endosomal toll like receptors and their downstream signaling pathways

OBJECTIVES

From the ancient, medicinal benefits of Hyssop (Hyssopus officinalis L.) have been implicated for respiratory and digestive diseases despite the effects of Hyssop on viral infections have not been mechanistically investigated. In this study, we examined whether the Hyssop extract activated anti-viral innate immunity, as a sentinel for immune system, through activation of endosomal TLRs recognizing nucleic acids and their downstream signaling. The Hyssop herb extracts was prepared and co-cultured with healthy individual's peripheral blood mononuclear cells (PBMCs). After viability assay, gene expression levels of TLR3,7,8,9, as well as MyD88 and NF-κB, were evaluated in treated PBMCs using Real-time PCR. Next, the secretion level of immune related cytokines was quantified via ELISA.

RESULTS

Post 24 h, 40 µg/ml of the extract significantly inhibited the viability of less than 50% of cells compared to the control and had a maximum effect on cellular function. The Hyssop-treated PBMCs demonstrated an elevated expression of endosomal TLRs genes, as well as MyD88 and NF-κB. Moreover, the release of INF-α and β notably enhanced in cell culture supernatant, while the content of inflammatory cytokines remarkably diminished (P < 0.05). The Hyssop extract was capable of inducing antiviral innate immune responses so can be promising in antiviral drug strategies.

In vitro, in vivo and in silico evaluation of the anti-inflammatory potential of Hyssopus officinalis L. subsp. aristatus (Godr.) Nyman (Lamiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal properties of hyssop have been used in traditional medicine since ancient times, inter alia, in diseases/conditions with an inherent inflammatory process.

AIM OF THE STUDY

Accordingly, the aim of this study was to investigate the anti-inflammatory properties of hyssop herb preparations (essential oil and methanol extracts) in vivo, in vitro and in silico.

MATERIALS AND METHODS

For in vitro testing of essential oils and extracts of hyssop herb, the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzyme assays were used. In vivo anti-inflammatory potential of the extracts (at doses of 50, 100 and 200 mg/kg) was assessed using the carrageenan-induced rat paw edema test. Molecular docking and dynamics were used for in silico testing of the inhibitory activity of chlorogenic (CA) and rosmarinic (RA) acids, as the dominant compounds in the tested methanol extracts against COX-1 and COX-2 enzymes.

RESULTS

Significant inhibitory activity was shown in the COX-2 test regarding extracts (essential oils did not exhibit any significant activity). Namely, all analyzed extracts, at a concentration of 20 μg/mL, showed a percentage of inhibition of COX-2 enzyme (54.04-63.04%), which did not indicate a statistically significant difference from the positive control of celecoxib (61.60%) at a concentration of 8.8 μM. In vivo testing showed that all methanol extracts of hyssop herb, at the highest test dose of 200 mg/kg in the third and fourth hours, after carrageenan administration, exhibited a statistically significant (p < 0.05) inhibitory effect on the increase in rat paw edema in relation to control. This activity is comparable or higher in relation to the reference substance, indomethacin, at a concentration of 8 mg/kg. The preliminary in silico results suggest that investigated compounds (RA and CA) showed better inhibitory activity against COX-1 and COX-2 than standard non-steroidal anti-inflammatory drug (NSAID), ibuprofen, as evident from the free binding energy (ΔG_bind in kJ mol^-1). The binding energies of the docked compounds to COX-1 and -2 were found to be in the range between -47.4 and -49.2 kJ mol^-1. Ibuprofen, as the one NSAID, for the same receptors targets, showed remarkably higher binding energy (ΔG_bind = -31.3 kJ mol^-1 to COX-1, and ΔG_bind = -30.9 kJ mol^-1 to COX-2).

CONCLUSION

The results obtained not only support the traditional use of hyssop herb in inflammatory conditions in folk medicine, but also open the door to and the need for further in vivo testing of extracts in order to examine the molecular mechanism of anti-inflammatory activity in living systems and possibly develop a new anti-inflammatory drug or supplement.

Antioxidant, Antigenotoxic and Cytotoxic Activity of Essential Oils and Methanol Extracts of Hyssopus officinalis L. Subsp. aristatus (Godr.) Nyman (Lamiaceae)

Hyssopus officinalis L. is a well-known aromatic plant used in traditional medicine and the food and cosmetics industry. The aim of this study is to assess the antioxidant, genotoxic, antigenotoxic and cytotoxic properties of characterized hyssop essential oils and methanol extracts. Chemical composition was analyzed by gas chromatography - mass spectrometry (GC-MS) and liquid chromatography with diode array detection and mass spectrometry (LC-DAD-MS), respectively. Antioxidant activity was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) tests; genotoxic and antigenotoxic activity were examined by the comet assay, while cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide dye (MTT) test against tumor cell lines (SW480, MDA-MB 231, HeLa) and non-transformed human lung fibroblast cell lines (MRC-5). The essential oils were rich in monoterpene hydrocarbons (e.g., limonene; 7.99–23.81%), oxygenated monoterpenes (1,8-cineole; 38.19–67.1%) and phenylpropanoids (methyl eugenol; 0.00–28.33%). In methanol extracts, the most abundant phenolics were chlorogenic and rosmarinic acid (23.35–33.46 and 3.53–17.98 mg/g, respectively). Methanol extracts expressed moderate to weak antioxidant activity (DPPH IC₅₀ = 56.04–199.89 µg/mL, FRAP = 0.667–0.959 mmol Fe²⁺/g). Hyssop preparations significantly reduced DNA damage in human whole blood cells, induced by pretreatment with hydrogen peroxide. Methanol extracts exhibited selective and potent dose- and time-dependent activity against the HeLa cell line. Results of the current study demonstrated notable H. officinalis medicinal potential, which calls for further investigation.

Wild Italian Hyssopus officinalis subsp. aristatus (Godr.) Nyman: From Morphological and Phytochemical Evidences to Biological Activities

Three specimens of H. officinalis subsp. aristatus were collected in three areas of the Abruzzo region (Italy) and subjected to macroscopic and microscopic observation to support their botanical identification. The essential oils (EOs) obtained from the aerial parts of the samples were characterized with the object to define their phytochemical and pharmaceutical biology profile. They highlight three different chemotypes, including one never seen in previous literature (CIV17-EO, distilled from sample harvested in 2017 at Civitaretenga), that showed a fingerprinting with the predominance of (-)-limonen-10-yl-acetate (67.9%). In 2017 European Food Safety Authority (EFSA) reported the genotoxicity of similar compounds, therefore, to dismiss any safety concern for the CIV17-EO use as flavouring substance, the Ames test was performed with no evidence of mutagenic activity. Safety of use coupled with chemical characterization of this new chemotype set the stage for a better standardization of H. officinalis EOs. The ethanolic extracts, on the other hand, with qualitatively similar chemical profiles in which caftaric, chlorogenic and rosmarinic acid were the main molecules, showed interesting antioxidant activity and a slight cytotoxicity towards the A549 cell line that could indicate a starting point for the evaluation of an additional preventive tool for maintaining health status.

Potential Use of Hyssopus officinalis and Borago officinalis as Curing Ingredients in Pork Meat Formulations

Simple Summary

Health risks associated with nitrites as curing agents have led consumers to search for products without those additives. Herbs have been used in medicine for many years and are usually positively perceived by consumers. Good-quality products with medicinal plants may be an alternative for those who try to avoid additives other than salt and spices. Hyssopus officinalis and Borago officinalis were tested for their potential to be used as colour forming and antioxidant agents. Both herbs were used in pork meat formulations along with nitrate reducing bacteria. A colour formation similar to a control product containing nitrite was noted in all the samples. Borage had a stronger antioxidant effect. Those additives can be used as an alternative to nitrite cured pork products.

Abstract

The replacement of nitrites in pork meat products has been a studied issue for many years. Due to potential health threats associated with these additives, consumers tend to search for alternative meat curing methods. In this study, Hyssopus officinalis and Borago officinalis were tested for their potential to be used as colour-forming and antioxidant agents. Dry plant samples from various sources were tested for fat, protein, ash, polyphenol and nitrate content. There were significant differences between the herbs depending on source. Two control samples (containing curing salt and sodium chloride with nitrate reducing bacteria) and samples with herbs (hyssop, hyssop with nitrate reducing bacteria, borage, borage with nitrate reducing bacteria)—0.5% of the meat mass—were prepared and stored for 15 days. In the samples with herbs and bacterial cultures, a red colour was developed, the TBARS values were low and DPPH activity was strong. All the samples with herbs had lower residual nitrite levels compared to the samples with curing salt. Borage had a stronger influence on colour and antioxidant stability of the meat samples compared to hyssop. However, both herbs can be used as colour-forming and antioxidant agents along with nitrate-reducing bacteria.

Gas Sensors Based on Chemi-Resistive Hybrid Functional Nanomaterials

Chemi-resistive sensors based on hybrid functional materials are promising candidates for gas sensing with high responsivity, good selectivity, fast response/recovery, great stability/repeatability, room-working temperature, low cost, and easy-to-fabricate, for versatile applications. This progress report reviews the advantages and advances of these sensing structures compared with the single constituent, according to five main sensing forms: manipulating/constructing heterojunctions, catalytic reaction, charge transfer, charge carrier transport, molecular binding/sieving, and their combinations. Promises and challenges of the advances of each form are presented and discussed. Critical thinking and ideas regarding the orientation of the development of hybrid material-based gas sensor in the future are discussed.