Investigation of chemical compounds, antioxidant and antimicrobial properties of teucrium arduini L. (lamiaceae)

Phytochemical Traits and Biological Activity of Eryngium amethystinum and E. alpinum (Apiaceae)

Eryngium amethystinum L. is a wild vegetable used in Croatia. Both E. amethystinum and E. alpinum L. are decorative plants that can also be used in horticulture. To find out the hidden qualities of these two species, the following biological activities were studied: essential oil (EO) composition, analyzed by gas chromatography and gas chromatography with mass spectrometry (GC, GC–MS); phenolic compound content (PC), analyzed by high performance liquid chromatography (HPLC); total phenols as well as total flavonoids, analyzed by ultraviolet–visible spectrophotometry (UV/Vis); antioxidants, analyzed by 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity (DPPH), β-carotene-linoleic acid assay, chelating activity and reducing power of the extracts; and antimicrobial evaluation by micro-dilution assay and inhibition of Candida albicans blastospore germination. The major constituents of EO were β-caryophyllene (15.2%), α-pinene (10.2%) and 2,3,6-trimethylbenzaldehyde (9.3%) for E. amethystinum and caryophyllene oxide (27.9%), bicyclogermacrene (13.2%) and germacrene D (8.2%) for E. alpinum. The methanol extracts of both species showed a broad spectrum of antibacterial and antifungal activity with minimum inhibitory concentrations (MIC) less than or equal to 1.944 and 1.11 mg/mL, respectively.

A Review of the Phytochemistry, Traditional Uses and Biological Activities of the Essential Oils of Genus Teucrium

The genus Teucrium is a large and polymorphic genus of the Lamiaceae family distributed in mild climate zones, particularly in the Mediterranean basin and Central Asia. Studies of nonvolatile constituents of Teucrium species showed that they are a rich source of neo-clerodane diterpenoids, considered as chemotaxonomic markers of the genus. In addition to the nonvolatile metabolites, there has been a large interest in the essential oils of this genus. In this review, a complete survey of the chemical composition and biological properties of the essential oils isolated from Teucrium taxa is provided. In traditional medicine, since ancient times, species of this genus have been widely implemented for their biological properties, including antimicrobial, anti-inflammatory, antispasmodic, insecticidal, anti-malaria, etc. Therefore, a complete review of all of the traditional uses of Teucrium taxa are also reported.

Phytochemical Screening, Antibacterial, Antifungal, Antiviral, Cytotoxic, and Anti-Quorum-Sensing Properties of Teucrium polium L. Aerial Parts Methanolic Extract

The chemical profile of Teucrium polium L. (T. polium) methanolic extract was tested using liquid chromatography coupled with high resolution mass spectrometry (HR-LCMS). Disc diffusion and microdilution assays were used for the antimicrobial activities. Coxsackievirus B-3 (CVB3) and Herpes simplex virus type 2 (HSV-2) were used for the antiviral activities. Chromobacterium violaceum (ATCC 12472 and CV026) and Pseudomonas aeruginosa PAO1 were used as starter strains for the anti-quorum sensing tests. Isoprenoids are the main class of compounds identified, and 13R-hydroxy-9E,11Z-octadecadienoic acid, valtratum, rhoifolin, sericetin diacetate, and dihydrosamidin were the dominant phytoconstituents. The highest mean diameter of growth inhibition zone was recorded for Acinetobacter baumannii (19.33 ± 1.15 mm). The minimal inhibitory concentrations were ranging from 6.25 to 25 mg/mL for bacterial strains, and from 6.25 to 25 mg/mL for Candida species. The 50% cytotoxic concentration on VERO (African Green Monkey Kidney) cell lines was estimated at 209 µg/mL. No antiviral activity was recorded. Additionally, T. polium extract was able to inhibit P. aeruginosa PAO1 motility in a concentration-dependent manner. However, the tested extract was able to inhibit 23.66% of the swarming and 35.25% of swimming capacities of PAO1 at 100 µg/mL. These results highlighted the role of germander as a potent antimicrobial agent that can interfere with the virulence factors controlled by the quorum-sensing systems.

Methanol extracts of Teucrium arduini L. and Teucrium flavum L. induce protective effect against mitomycin C in human lymphocytes in vitro

The study was designed to evaluate antigenotoxic effect of methanol Teucrium arduini and Teucrium flavum extracts against mitomycin C (MMC)-induced chromosome and DNA damage in vitro. Cytokinesis-block micronucleus (CBMN) and comet assays were used to investigate effect of plant extracts in different concentrations (125, 250, 500 and 1000 µg/mL) on human peripheral blood lymphocytes (PBLs). The obtained results showed that the all tested concentrations of T. arduini and the highest concentration of T. flavum significantly reduced the MMC-induced micronucleus (MN) frequency in comparison to positive control (only MMC). There were significantly negative correlations between the extracts concentrations and MN frequencies (Pearson, r = -0.905, p = 0.0001 for T. arduini; r = -0.861, p = 0.0001 for T. flavum). The extracts of both plants further lowered the MMC-decreased nuclear division index (NDI) in a dose dependent-manner (Pearson, r = -0.837, p = 0.001 for T. arduini; r = -0.598, p = 0.040 for T. flavum), but significantly only in the highest concentration (1000 µg/mL). Comet assay showed that extracts reduced MMC-increased genetic damage index (GDI), significantly in the concentrations of 500 and 1000 μg/mL, in comparison with positive control. Based on our results, it can be concluded that methanol T. arduini and T. flavum extracts possess protective proapoptotic and antigenotoxic effect which is indication of their medicinal relevance and use in treatment.

Anti-Candida Activity of Essential Oils from Lamiaceae Plants from the Mediterranean Area and the Middle East

Extensive documentation is available on plant essential oils as a potential source of antimicrobials, including natural drugs against Candida spp. Yeasts of the genus Candida are responsible for various clinical manifestations, from mucocutaneous overgrowth to bloodstream infections, whose incidence and mortality rates are increasing because of the expanding population of immunocompromised patients. In the last decade, although C. albicans is still regarded as the most common species, epidemiological data reveal that the global distribution of Candida spp. has changed, and non-albicans species of Candida are being increasingly isolated worldwide. The present study aimed to review the anti-Candida activity of essential oils collected from 100 species of the Lamiaceae family growing in the Mediterranean area and the Middle East. An overview is given on the most promising essential oils and constituents inhibiting Candida spp. growth, with a particular focus for those natural products able to reduce the expression of virulence factors, such as yeast-hyphal transition and biofilm formation. Based on current knowledge on members of the Lamiaceae family, future recommendations to strengthen the value of these essential oils as antimicrobial agents include pathogen selection, with an extension towards the new emerging Candida spp. and toxicological screening, as it cannot be taken for granted that plant-derived products are void of potential toxic and/or carcinogenic properties.

Genotoxic and cytotoxic properties of two medical plants (Teucrium arduini L.and Teucrium flavum L.) in relation to their polyphenolic contents

A large number of species belonging to the genus Teucrium are used in pharmacy and traditional medicine for the treatment of different diseases. This study aimed to evaluate the polyphenolic composition as well as genotoxic and cytotoxic effects of methanolic extracts from T. arduini and T. flavum, two native species found in Montenegro. We determined the total phenolic and flavonoid contents of these plants using spectrophotometric methods; the qualitative content of polyphenolic compounds was investigated by high-performance liquid chromatography (HPLC). Genotoxicity in cultured human lymphocytes was measured in the cytokinesis-block micronucleus assay (CBMN) and comet assay in the range between 125 and 1000 μg/mL. Cytotoxicity was assessed by the MTT viability assay in normal human MRC-5 fibroblasts and MDA-MB-231 breast carcinoma cells. The content of total phenolics and flavonoids in T. arduini extract was higher than in T. flavum (200.35 mg GA/g vs. 171.08 mg GA/g; 96.32 mg RU/g vs. 78.14 mg RU/g). The polyphenolic composition of both extracts was qualitatively similar and eight phenol compounds were identified. The most commonly present phenol was caffeic acid and among four flavonoids, the most common was quercetin. Both plant extracts were genotoxic in both the CBMN and comet assays at concentrations of 250, 500 and 1000 μg/mL. After 72 h of exposure, the extracts of T. arduini and T. flavum were found to induce cytotoxicity in MRC-5 fibroblasts but not in MDA-MB-231 breast cancer cells. The results suggest that the constituents of both plant species are genotoxic and cytotoxic, therefore these extracts warrant additional evaluation to be safely applied in humans.

Exploration of Medicinal Plants as Sources of Novel Anticandidal Drugs

BACKGROUND

Human infections associated with skin and mucosal surfaces, mainly in tropical and sub-tropical parts of the world. During the last decade, there have been an increasing numbers of cases of fungal infections in immunocompromised patients, coupled with an increase in the number of incidences of drug resistance and toxicity to anti fungal agents. Hence, there is a dire need for safe, potent and affordable new antifungal drugs for the efficient management of candidal infections with minimum or no side effects.

INTRODUCTION

Candidiasis represents a critical problem to human health and a serious concern worldwide. Due to the development of drug resistance, there is a need for new antifungal agents. Therefore, we reviewed the different medicinal plants as sources of novel anticandidal drugs.

METHODS

The comprehensive and detailed literature on medicinal plants was carried out using different databases, such as Google Scholar, PubMed, and Science Direct and all the relevant information from the articles were analyzed and included.

RESULTS

Relevant Publications up to the end of November 2018, reporting anticandidal activity of medicinal plants has been included in the present review. In the present study, we have reviewed in the light of SAR and mechanisms of action of those plants whose extracts or phytomolecules are active against candida strains.

CONCLUSION

This article reviewed natural anticandidal drugs of plant origin and also summarized the potent antifungal bioactivity against fungal strains. Besides, mechanism of action of these potent active plant molecules was also explored for a comparative study. We concluded that the studied active plant molecules exhibit potential antifungal activity against resistant fungal strains.

Antimicrobial, Antioxidant, and Cytotoxic Activities of Ocimum forskolei and Teucrium yemense (Lamiaceae) Essential Oils

Background:Ocimum forskolei and Teucrium yemense (Lamiaceae) are used in traditional medicine in Yemen. Methods: The chemical composition, antimicrobial, antioxidant and cytotoxic activities of the essential oils isolated from the leaves of Ocimum forskolei Benth. (EOOF) and two different populations of Teucrium yemense Deflers., one collected from Dhamar province (EOTY-d), and another collected from Taiz (EOTY-t) were investigated. The antimicrobial activities of the oils were evaluated against several microorganisms with the disc diffusion test or the broth microdilution test. The essential oils were screened for in-vitro cytotoxic activity against human tumor cells. EOOF and EOTY-d were screened for free-radical-inhibitory activity using the DPPH radical scavenging assay. Results: Sixty-four compounds were identified in (EOOF) representing 100% of the oil content with endo-fenchol (31.1%), fenchone (12.2%), τ-cadinol (12.2%), and methyl (E)-cinnamate (5.1%) as the major compounds. In EOTY-d, 67 compounds were identified, which made up 91% of the total oil. The most abundant constituents were (E)-caryophyllene (11.2%), α-humulene (4.0.%), γ-selinene (5.5%), 7-epi-α-selinene (20.1%), and caryophyllene oxide (20.1%), while the major compounds in EOTY-t were α-pinene (6.6%), (E)-caryophyllene (19.1%) α-humulene (6.4%), δ-cadinene (6.5%), caryophyllene oxide (4.3%), α-cadinol (9.5%), and shyobunol (4.6%). The most sensitive microorganisms for EOOF were B. subtilis, S. aureus, and C. albicans with inhibition zones of 34, 16, and 24 mm and MIC values of, 4.3 mg/mL, 4.3 mg/mL, and 8.6 mg/mL, respectively. EOTY-t showed antimicrobial activity against S. aureus, B. cereus, A. niger, and B. cinerea with MIC values of 0.156, 0.156, 0.313 and 0.313 mg/mL, respectively. Neither essential oil showed remarkable radical inhibition (IC₅₀ = 31.55 and 31.41 μL/mL). EOTY-d was active against HT-29 human colorectal adenocarcinoma cell lines with IC₅₀ = 43.7 μg/mL. Consistent with this, EOTY-t was active against both MCF-7 and MDA-MB-231 human breast adenocarcinoma cells. Conclusions: The antimicrobial activity of Ocimum forskolei essential oil against B. subtilis and C. albicans is consistent with its traditional use in Yemeni traditional medicine to treat skin infections. Both O. forskolei and T. yemense show wide variations in their respective essential oil compositions; there remains a need to investigate both species botanically, genetically, and phytochemically more comprehensively.

Potential Use of Phenolic Acids as Anti-Candida Agents: A Review

There has been a sharp rise in the occurrence of Candida infections and associated mortality over the last few years, due to the growing body of immunocompromised population. Limited number of currently available antifungal agents, undesirable side effects and toxicity, as well as emergence of resistant strains pose a considerable clinical challenge for the treatment of candidiasis. Therefore, molecules that derived from natural sources exhibiting considerable antifungal properties are a promising source for the development of novel anti-candidal therapy. Phenolic compounds isolated from natural sources possess antifungal properties of interest. Particularly, phenolic acids have shown promising in vitro and in vivo activity against Candida species. However, studies on their mechanism of action alone or in synergism with known antifungals are still scarce. This review attempts to discuss the potential use, proposed mechanisms of action and limitations of the phenolic acids in anti-candidal therapy.

Morphological, genetic and phytochemical variation of the endemic Teucrium arduini L. (Lamiaceae)

Analysis of the morphological traits of leaves, genetic variability (analyzed by AFLP) and chemical composition of essential oils (analyzed by GC-MS) was conducted on eleven populations of the endemic Illyric-Balcanic species Teucrium arduini L. in Croatia, Bosnia and Herzegovina, and Montenegro. Average blade length and width ranged from 20.00 to 31.47mm and from 11.58 to 15.66mm, respectively. Multivariate analysis (PCA, UPGMA) of morphological traits distinguished two continental Bosnian populations from the remaining populations. AFLP analysis separated the investigated populations into two groups based primarily on geographical distance. Essential oil analysis showed a total of 52 compounds, with two chemotypes distinguished based on the essential oil profile. The first was a sesquiterpene chemotype, with β-caryophyllene, germacrene D or caryophyllene oxide as the major compounds, while the second was an oxygenated monoterpene chemotype, with pulegone and piperitone oxide as the main components. The Mantel test showed a stronger correlation between the morphological traits and AFLP than between the essential oil profile and AFLP. The test also showed a stronger association between the essential oil profile and geographical position than between the morphological traits and geographical position.

Antioxidant and Antiacetylcholinesterase Activity of Teucrium hyrcanicum

Background:

Teucrium hyrcanicum belonging to the Lamiaceae family is a native plant in Iran; it is called Maryam nokhodi-e-jangali in Farsi.

Objective:

The aim of this study is to evaluate acetylcholinesterase inhibition (AChEI), antioxidant activity and flavonoids content of T. hyrcanicum methanol extract.

Materials and Methods:

The air-dried and the ground aerial parts of T. hyrcanicum were extracted by percolation method with methanol. Antioxidant activity of the extract was investigated by using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power assay (FRAP) methods. In addition, AChEI and flavonoid content of T. hyrcanicum methanol extract were measured.

Results:

The results showed that total flavonoid content of T. hyrcanicum in reference to the standard curve for quercetin was 20.70 ± 0.05 mg quercetin equivalents/g of extract. In the FRAP method, the antioxidant activity of T. hyrcanicum extract and butyl hydroxyanisole (BHA) (as a positive control) were 657.5 ± 0.04 and 880 ± 0.06 mmol Fe II/1 g dried extract. According to results of DPPH assay, half maximal inhibitory concentration (IC₅₀) value for DPPH radical-scavenging activities of T. hyrcanicum methanol extract, vitamin E and BHA were 74.6, 14.12 and 7.8 μg/mL, respectively. IC₅₀ value for AChEI of T. hyrcanicum and donepezil as a positive control were 2.12 mg/mL and 0.013 mg/mL.

Conclusion:

The results of the present study showed T. hyrcanicum is a natural antioxidant that the flavonoid content can be responsible for extract effects.

Genetic and phytochemical variability of six Teucrium arduini L. populations and their antioxidant/prooxidant behaviour examined by biochemical, macromolecule- and cell-based approaches

Teucrium arduini L., an Ilyric-Balcanic endemic species, has been reported for decades as a valuable plant used in traditional medicine for treating digestive disorders. The present study evaluated genetic and phytochemical variability of six T. arduini populations in order to determine factors that influence an accumulation of polyphenolic compounds. Results strongly suggest that a phytochemical variation was caused by environmental rather than genetic factors. T. arduini leaf extract from the locality Učka, which accumulated significantly more polyphenolic phytochemicals in comparison to others, showed antioxidant activity in DNA and lipid bioassays. Furthermore, the same extract exhibited prooxidant behaviour at protein level and induce formation of reactive oxygen species in human laryngeal carcinoma cells causing cytotoxic activity, in a dose dependent manner. All the results of the present study suggested that T. arduini extract could be responsible for antioxidative/prooxidative mechanisms and would help in determination of optimal conditions for their ethnopharmacological use.