Salvia verbenaca L. essential oil: Variation of yield and composition according to collection site and phenophase

Variation in Terpenoid and Flavonoid Content in Different Samples of Salvia semiatrata Collected from Oaxaca, Mexico, and Its Effects on Antinociceptive Activity

Salvia semiatrata Zucc. (Lamiaceae) is endemic to Oaxaca, Mexico, and is known for its analgesic properties. Terpenoids and phenolic compounds with antinociceptive potential have been characterised from this species. The aim of this research was to determine the variation in terpenoids and flavonoids in ethyl acetate extracts of S. semiatrata collected from ten different localities, as well as to evaluate the antinociceptive effect between plants with higher and lower contents of these secondary metabolites. Quantification of S. semiatrata compounds was performed via HPLC-DAD, whereas in vivo evaluation of the antinociceptive effect was performed via formalin test. The results showed that the most abundant groups of metabolites are oleanolic acid (89.60-59.20 µg/mg), quercetin (34.81-16.28 µg/mg), catechin (11.30-9.30 µg/mg), and 7-keto-neoclerodan-3,13-dien-18,19:15,16-diolide (7-keto) (8.01-4.76 µg/mg). Principal component and canonical correspondence analysis showed that the most contrasting localities in terms of compound content and climatic variables are Miahuatlán and Santiago Huauclilla. The differences in metabolite content between the two locations did not affect the antinociceptive effects evaluated at a dose of 300 mg/kg, p.o. In conclusion, the results indicate that S. semiatrata is effective in relieving pain, regardless of the site of collection, reinforcing its traditional use as analgesic.

Flowering phenophases influence the antibacterial and anti-biofilm effects of Thymus vulgaris L. essential oil

BACKGROUND

Essential oils are becoming increasingly popular in medicinal applications because of their antimicrobial effect. Thymus vulgaris L. (Lamiaceae) is a well-known and widely cultivated medicinal plant, which is used as a remedy for cold, cough and gastrointestinal symptoms. Essential oil content of thyme is responsible for its antimicrobial activity, however, it has been reported that the chemical composition of essential oils influences its biological activity. In order to explore flowering phenophases influence on the chemical composition of thyme essential oil and its antibacterial and anti-biofilm activity, plant materials were collected at the beginning of flowering, in full bloom and at the end of flowering periods in 2019.

METHODS

Essential oils from fresh and dried plant materials were distilled and analyzed with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). The antibacterial activity was performed by broth microdilution and thin layer chromatography-direct bioautography (TLC-DB) assays and the anti-biofilm effect by crystal violet assay, respectively. Scanning electron microscopy was applied to illustrate the cellular changes of bacterial cells after essential oil treatment.

RESULTS

Thymol (52.33-62.46%) was the main component in the thyme essential oils. Thyme oil distilled from fresh plant material and collected at the beginning of flowering period exerted the highest antibacterial and anti-biofilm activity against Haemophilus influenzae, H. parainfluenzae and Pseudomonas aeruginosa.

CONCLUSION

The different flowering periods of Thymus vulgaris influence the antibacterial and anti-biofilm activity of its essential oils, therefore, the collection time has to be taken into consideration and not only the full bloom, but the beginning of flowering period may provide biological active thyme essential oil.

Chemical Composition and In Vitro Antioxidant Activity of Salvia aratocensis (Lamiaceae) Essential Oils and Extracts

Salvia aratocensis (Lamiaceae) is an endemic shrub from the Chicamocha River Canyon in Santander (Colombia). Its essential oil (EO) was distilled from the aerial parts of the plant via steam distillation and microwave-assisted hydrodistillation and analyzed using GC/MS and GC/FID. Hydroethanolic extracts were isolated from dry plants before distillation and from the residual plant material after distillation. The extracts were characterized via UHPLC-ESI^(+/-)-Orbitrap-HRMS. The S. aratocensis essential oil was rich in oxygenated sesquiterpenes (60-69%) and presented τ-cadinol (44-48%) and 1,10-di-epi-cubenol (21-24%) as its major components. The in vitro antioxidant activity of the EOs, measured via an ABTS^+• assay, was 32-49 μmol Trolox^® g^-1 and that measured using the ORAC assay was 1520-1610 μmol Trolox^® g^-1. Ursolic acid (28.9-39.8 mg g^-1) and luteolin-7-O-glucuronide (1.16-25.3 mg g^-1) were the major S. aratocensis extract constituents. The antioxidant activity of the S. aratocensis extract, obtained from undistilled plant material, was higher (82 ± 4 μmol Trolox^® g^-1, ABTS^+•; 1300 ± 14 μmol Trolox^® g^-1, ORAC) than that of the extracts obtained from the residual plant material (51-73 μmol Trolox^® g^-1, ABTS^+•; 752-1205 μmol Trolox^® g^-1, ORAC). S. aratocensis EO and extract had higher ORAC antioxidant capacity than the reference substances butyl hydroxy toluene (98 μmol Trolox^® g^-1) and α-tocopherol (450 μmol Trolox^® g^-1). S. aratocensis EOs and extracts have the potential to be used as natural antioxidants for cosmetics and pharmaceutical products.

Chemical composition and biological activities of the essential oils from Lippia alba and Lippia origanoides

There is an increasing interest in essential oils extracted from Verbenaceae plant species as potential sources of biologically active compounds that could provide a starting point for designing novel phyto-pharmaceuticals in aquaculture. The present study was aimed to investigate the chemical composition, antioxidant activity, acute toxicity and antimicrobial effects against Vibrio parahaemolyticus of essential oils extracted from Lippia alba and L. origanoides. Approximately 23 components were identified and quantified by gas chromatography-mass spectrometry and flame ionization detection in each species' essential oil. The most predominant compounds were geranial (23.0%), limonene (17.0%) and neral (15.5%) in L. alba, and thymol (47.2%), p-cymene (16.0%) and E-caryophyllene (11.3%) in L. origanoides. The essential oils have antibacterial activity against Vibrio parahaemolyticus presenting Minimum Inhibitory Concentration (MIC) and Bactericidal Concentration (MBC) values between 156-625 µg mL-1. The essential oils also show antioxidant potential estimated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assays, presenting IC50 of 60.16 mg mL-1 and 0.22 mg mL-1 for L. alba and L. origanoides EO, respectively. Both oils were classified as toxic to Artemia salina nauplii. Therefore, these essential oils may be useful for controlling pathogenic bacteria important to the aquaculture industry.

Nine-dimensional bioprofiles of Tunisian sages (Salvia officinalis, S. aegyptiaca and S. verbenaca) by high-performance thin-layer chromatography - effect-directed analyses

Ethyl acetate extracts of Tunisian Salvia aegyptiaca and S. verbenaca aerial parts and S. officinalis leaves were examined via bioanalytical profiling using high-performance thin-layer chromatography (HPTLC) combined with nine bioactivity assays, namely antibacterial (Aliivibrio fischeri, Bacillus subtilis, and Rhodococcus fascians), antifungal (Bipolaris sorokiniana, and Fusarium avenaceum), radical scavenging (DPPH•), and enzyme inhibitory (α-glucosidase, acetylcholinesterase, and lipase) ones. The screening, using toluene - ethyl acetate - methanol 6:3:0.5 (V/V/V) as a mobile phase, revealed five bioactive zones (a-e) that were analyzed by HPTLC-electrospray ionization-mass spectrometry (ESI-MS). Zones b and c, observed exclusively in S. officinalis, were active in all assays except α-glucosidase, and only c inhibited F. avenaceum. Compounds in these zones were identified by HPLC-high resolution tandem MS (LC-HRMS/MS) as rosmanol/epi-rosmanol and methyl carnosate, respectively. In the bioactive zones a and e, corosolic/maslinic acid and ursolic/oleanolic acid isomer pairs were present, which could be identified in all three Salvia species after their HPTLC separation using pre-chromatographic derivatization with iodine and MS detection. The triterpenes inhibited B. subtilis and R. fascians bacteria and α-glucosidase enzyme. Linoleic and linolenic acids were detected in zone d, which showed strong lipase inhibition in all three sage species.

Revalorisation of Sage (Salvia lavandulifolia Vahl) By-Product Extracts as a Source of Polyphenol Antioxidants for Novel Jelly Candies

Sage (Salvia lavandulifolia Vahl) aqueous extracts (SE) obtained from distillation by-products were assessed as antioxidants for nutritionally enhanced jelly candies. Two experimental SEs with a different content of phenolic acids and flavonoids were tested: (i) SE38 (37.6 mg/g) and (ii) SE70 (69.8 mg/g), with salvianic and rosmarinic acids as main polyphenols, respectively. Flavour alteration, stability of sage polyphenols, physical quality traits and antioxidant capacity (AC) were studied in strawberry candies formulated without sugars and enriched with SEs at 0.25, 0.50 and 0.75 g/kg. Despite their different quantitative composition, SE38 and SE70 provided similar antioxidant properties, which were dose dependent. Salvianic and rosmarinic acids were stable without degrading to candy processing (up to 80 °C), keeping their antioxidant potential. There were no relevant differences in flavour or physical traits (pH, °Brix and CIELab colour) between untreated and SE-enriched strawberry candies. The addition of 0.75 g SE/kg resulted in relevant increases of candy AC: (i) from 30 to 38 mg GAE/100 g (total phenolics); (ii) from 10 to 17 mg TE/100 g (DPPH^• radical scavenging assay); (iii) from 5 to 13 mg TE/100 g (ABTS^·+ radical scavenging assay); (iv) from 84 to 163 µmol Fe²⁺/100 g (FRAP capacity) and (v) from to 75 to 83% (inhibition of deoxyribose damage). Sage distillation by-products can be revalorised as a source of natural antioxidants to produce healthier candies.

Phytochemistry and Biological Properties of Salvia verbenaca L.: A Comprehensive Review

The family Lamiaceae contains several plants used in traditional medicine to fight against different diseases. Salvia verbenaca L. (S. verbenaca) is one of the Lamiaceae species distributed around the Mediterranean regions. This plant exhibits different bioactive properties, including antibacterial, anticancer, antioxidant, antileishmanial, antidiabetic, immunomodulatory, and wound healing. This review was conducted to revise previous studies on S. verbenaca addressing its botanical description, geographical distribution, and phytochemical, pharmacological, and toxicological properties. Moreover, the main pharmacological actions of S. verbenaca major compounds were well investigated. Literature reports have revealed that S. verbenaca possesses a pivotal role in medicinal applications. The findings of this work noted that S. verbenaca was found to be rich in chemical compound classes such as terpenoids, phenolics, fatty acids, sterols, and flavonoids. Numerous studies have found that S. verbenaca essential oils and extracts have a wide range of biological effects. These results support the potential pharmacological properties of S. verbenaca and its traditional uses. This analysis can constitute a scientific basis for further refined studies on its pure secondary metabolites. Therefore, the outcome of the present work may support the perspective of identifying new therapeutical applications with detailed pharmacological mechanisms of S. verbenaca to prevent the development of some diseases such as neurodegenerative disorders. However, toxicological investigations into S. verbenaca are needed to assess any potential toxicity before it can be further used in clinical studies.

Essential Oil, Aroma, and Fatty Acid Profiles of Five Endemic Salvia Taxa from Turkey with Chemometric Analysis

The essential oil, aroma, and fatty acid compositions of Salvia cerino-pruinosa var. cerino-pruinosa, S. cerino-pruinosa var. elazigensis, S. pseudeuphratica, S. rosifolia, and S. kurdica collected in 2015, 2016, and 2017 were analysed by GC-FID, GC/MS/Head Space and GC/MS. The results were evaluated chemometrically for principal component analyses and hierarchical clustering analyses using Minitab program. The main components of their essential oils have been determined as germacrene-D (41.79 % highest for these species), camphor (55.80 %), linalool (33.38 %), caryophyllene oxide (32.99 %), 1,8-cineole (26.30 %) and geraniol acetate (31.63 %), while for aroma 1,8-cineole (45.95 % highest for these species), camphor (58.54 %), D-limonene (40.83 %), linalool (27.67 %) and cis-linalool oxide (25.87 %). Oleic (72.65 % highest for these species), erucic (44.61 %), 2-palmitoleic (42.17 %) and nervonic (32.61 %) acids were determined as major components of their fatty acids. According to the PCA and HCA, the essential oil components of these Salvia taxa unaffected by the years, and accordingly, the Salvia taxa grouped among themselves.

Volatile Composition Variability of Arnica montana Wild Populations of Trentino-Alto Adige, Italy, Determined by Headspace-Solid Phase Microextraction

Arnica montana is a plant distributed in most of Europe, including the Alpine arc and Apennines in Italy, and traditionally used worldwide for medicinal properties. Twelve natural populations of the species from Trentino-Alto Adige, Italy, were characterized using Headspace-Solid Phase Microextraction analysis for their volatile profile. Fifty-one compounds were detected in flower heads, the most abundant being (E)-Caryophyllene (23.4 %), 2,2,4,6,6-Pentamethylheptane (8.3 %), α- trans-Bergamotene (7.2 %), Germacrene D (5.7 %), and Hexanal (5.3 %). A multivariate analysis performed on the ten most abundant compounds grouped these investigated accessions into five main clusters. Three clusters, comprising together five accessions, were linked to the geographical origin of two collection sites. This work is a complete characterization of volatiles of the species by SPME analysis reported to date. Furthermore, results suggest that the species' volatile profile can be linked to the geographical origin of the natural populations and, therefore, represent a tool for evaluating biodiversity within the species.

The Impact of Geographical Location on the Chemical Compositions of Pimpinella lutea Desf. Growing in Tunisia

Essential oils are generally produced to confer the protection of medicinal plants against several natural enemies. Variations of chemical and physical environmental factors exert significant influences on plant development. They hence may affect the quality and quantity of volatile organic metabolites of interest and, therefore, the economic applications of essential oils. This research focused on the effects of the harvest region on the production and analytes present in Tunisian Pimpinella lutea Desf. Apiaceae that were collected in three different growing environments (North and South Bizerta and Tabarka). Essential oils extracted from a variety of genotypes were analyzed, for the first time, using gas chromatography and mass spectrometry (GC/FID and GC/MS). The determination of the percentage of essential oil components allowed the recognition of three chemotypes: α-trans-Bergamotene quantified at a percentage of 18.1% in North Bizerta (NBEO), muurola-4,10(14)-dien-1-β-ol identified in South Bizerta (10.1%, SBEO) and acora-3,7(14)-dien present in a high level of 29.1% in Tabarka population (TEO). The richness of different populations in sesquiterpenes (60.2–78.1%) suggests that Pimpinella lutea Desf. may be used in different industrial segments.

Health beneficial and pharmacological properties of p-cymene

p-cymene also known as p-cymol or p-isopropyltoluene is an alkyl-substituted aromatic compound naturally occurring in essential oils (EOs) of various aromatic plants, including the genus of Artemisia, Protium, Origanum, and Thymus. It is related to the family of terpenes, especially monocyclic monoterpenes. p-cymene is also present in several food-based plants such as carrots, orange juice, grapefruit, tangerine, raspberries and several spices. Numerous studies have demonstrated the pharmacological properties of the monoterpenes p-cymene, including antioxidant, anti-inflammatory, antiparasitic, antidiabetic, antiviral, antitumor, antibacterial, and antifungal activities. The p-cymene has also been reported to act as an analgesic, antinociceptive, immunomodulatory, vasorelaxant and neuroprotective agent. Its anticancer effects are related to some mechanisms such as the inhibition of apoptosis and cell cycle arrest. In this review, we critically highlighted the in vitro and in vivo pharmacological properties of the p-cymene molecule, providing insight into its mechanisms of action and potential applications in drug discovery. In light of this finding, in-depth in vivo studies are strongly required to validate the safety and beneficial effects of the p-cymene molecule in human healthcare and industrial applications as a potential source of drug discovery.

Chemical diversity and biological activities of essential oils from native populations of Clinopodium menthifolium subsp. ascendens (Jord.) Govaerts

This study is focused on the analysis of regional variation of the chemical compositions of three Clinopodium menthifolium subsp. ascendens (Jord.) Govaerts Tunisian accession, as well as their inhibition toward fungi and insect pests. The diversity of the chemical constituents and biological activities in front of the aforementioned variations was found to be remarkable. Essential oils were obtained by hydrodistillation of the aerial parts and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 41, 42, and 30 compounds were identified respectively from Clinopodium menthifolium essential oils harvested from three Tunisian regions, namely Ain-Draham (ADEO), Babouch (BEO), and Tabarka (TEO). All analyzed oils were rich in oxygenated monoterpenes with different major constituents. Piperitenone (34.5%), cis-piperitone oxide (26.1%), and pulegone (47.9%) were the dominant compounds in the three volatile oils, respectively. The antifungal activity was investigated in vitro using six targeted fungal strains (Aspergillus flavus, Aspergillus terreus, Candida albicans, Microsporum canis, Microsporum gypseum, and Trichophyton mentagrophytes). The toxicity and repellency of essential oils were evaluated against the stored product pest Tribolium confusum. The tested samples were differently effective toward the target fungi and the pest depending on the variability of their chemical compositions. BEO exhibited the highest fungitoxic properties toward A. terreus mold, M. canis dermatophyte, and C. albicans yeast (the MIC values ranged from 40 to 400 μg mL^-1). In addition, the data showed that TEO repelled T. confusum moderately (PR = 42.5% at 2 h after exposure). Concerning the contact treatment, both ADEO and BEO were proved to possess slightly toxic effects toward T. confusum pest (% of mortality 27.5-32.5% at 5% concentration). The results showed that the geographic origin greatly influenced the chemical composition and the associated bioactivities of Clinopodium menthifolium subsp. ascendens.

In vitro antioxidant, anticholinesterases, anti-α-amylase, and anti-α-glucosidase effects of Algerian Salvia aegyptiaca and Salvia verbenaca

In this study, Salvia aegyptiaca and Salvia verbenaca aerial part decoction and methanol extracts (SAE DE, SAE ME, SVR DE, and SVR ME) were screened for their in vitro antioxidant, anti-Alzheimer, and antidiabetic enzymes inhibition activities. The antioxidant properties of Salvia extracts were determined using DPPH radical scavenging, ABTS radical scavenging, Alkaline DMSO superoxide radical scavenging, β-carotene bleaching, reducing power, and metal chelating activity assays. All extracts showed high antioxidant capacity and the antioxidant properties with the best performance were detected in the SAE ME and SVR ME. The extracts of S. aegyptiaca and S. verbenaca showed a low inhibitory activity of acetylcholinesterase (AChE), whereas, the methanol extract of S. aegyptiaca had the highest inhibitory activity on butyrylcholinesterase (BChE) (71.60 ± 4.33% for 100 µg/ml) compared to the other extracts. In vitro inhibitory effect on diabetic enzymes showed that the ME inhibited α-amylase enzyme with an IC₅₀ 86 and 101 µg/ml for SAE and SVR, respectively. Similarly, both extracts inhibited α-glucosidase with (IC₅₀ 97 and 150 µg/ml, respectively). The decoction extracts exhibited lower activity on both enzymes. PRACTICAL APPLICATIONS: It is becoming evident that oxidative stress is involved in several acute and chronic diseases. Counteracting free radical generation has become one of the widest fields of research worldwide. This study deals with the in vitro antioxidant activity of two plants from the Salvia genus as well as the assessment of their in vitro inhibitory properties of four key enzymes implicated in diabetes and Alzheimer's disease. Concerning the practical applications of our work, it can be explored in its antioxidant part as a food supplement to prevent the excess of free radicals in the body and also in other industrial practices. Another potential use is in the prevention and amelioration of both diabetes and Alzheimer's disease symptoms for the extracts that had enzyme inhibitory activity, but this deserves further toxicological and in vivo studies.

Geographical variation of the chemical composition in essential oils extracted from Sardinian Salvia verbenaca

Salvia verbenaca is a perennial herbaceous plant well appreciated as medicinal herb which can be found in Mediterranean area, Europe, Africa and Asia. In this study, S. verbenaca flowers and leaves were collected in six different geographical areas of Sardinia (Italy). Information about the variation of the chemical composition of plants grown in different locations were obtained from gas chromatography analysis of the extracted essential oils. Gas chromatography analysis detected 33 compounds, which have been grouped in oxygenated monoterpenes, monoterpene hydrocarbons, sesquiterpenes and other compounds. The chemical composition of each group resulted significantly affected by sampling site in terms of geography and altitude. Concerning the geographical distribution of the detected chemicals, sesquiterpenes were found in considerable amount in three localities, monoterpenes hydrocarbons in two and other compounds were predominant only in one site. Regarding the altitude level, monoterpenes, sesquiterpenes and other compounds were predominant, respectively, at medium and medium-high altitude.

New Tricks for Old Guys: Recent Developments in the Chemistry, Biochemistry, Applications and Exploitation of Selected Species from the Lamiaceae Family

Lamiaceae is one of the largest families of flowering plants comprising about 250 genera and over 7,000 species. Most of the plants of this family are aromatic and therefore important source of essential oils. Lamiaceae are widely used as culinary herbs and reported as medicinal plants in several folk traditions. In the Mediterranean area oregano, sage, rosemary, thyme and lavender stand out for geographical diffusion and variety of uses. The aim of this review is to provide recent data dealing with the phytochemical and pharmacological studies, and the more recent applications of the essential oils and the non-volatile phytocomplexes. This literature survey suggests how the deeper understanding of biomolecular processes in the health and food sectors as per as pest control bioremediation of cultural heritage, or interaction with human microbiome, fields, leads to the rediscovery and new potential applications of well-known plants.