Study of antioxidant activity and some herbal compounds of Dracocephalum kotschyi Boiss. in different ages of growth

Multivariate analysis of the phytochemical composition and antioxidant properties in twenty-five accessions across three Achillea species

This study explored the chemical composition, antioxidant activity, and total phenol content of aerial parts from 25 accessions of three Achillea species (Achillea wilhelmsii C. Koch, Achillea vermicularis Trin., and Achillea tenuifolia Lam.). The plants were collected from various natural habitats across Iran, encompassing regions such as Central, Western, Southern, Northern, Western, and Northwestern parts of the country. Subsequently, they were grown together under field conditions. The study revealed significant variation in essential oil yields among accessions of A. wilhelmsii, ranging from 0.01 to 0.107%, A. vermicularis with a range of 0.075 to 1.5%, and A. tenuifolia showing a variation of 0.1 to 2%. The study utilized Gas Chromatography-Mass Spectrometry (GC-MS) analysis, revealing 75, 49, and 75 compounds in the essential oils of A. wilhelmsii, A. tenuifolia, and A. vermicularis, respectively. Major components included camphor, 1,8-cineole, anethole, α-pinene, and phytol in A. wilhelmsii, 1,8-cineole, camphor, levo-carvone, and δ-terpinene in A. vermicularis, and β-cubebene, elixene, β-sesquiphellandrene, 1,8-cineole, camphor, and δ-terpinene in A. tenuifolia. The essential oil compositions of A. wilhelmsii and A. vermicularis were predominantly characterized by oxygenated monoterpenes, whereas that of A. tenuifolia was characterized by sesquiterpenes. Cluster analysis grouped accessions into three clusters, with A. tenuifolia forming a distinct group. Principal Component Analysis (PCA) triplot (62.21% of total variance) confirmed these results and provided insights into compound contributions. Furthermore, total phenolic content and antioxidant activity of the accessions of three species were assessed over 2 years. A. tenuifolia exhibited the highest levels in both categories, with statistically significant linear regression between antioxidant activity and total phenol content for A. tenuifolia and A. wilhelmsii. These findings emphasize significant phytochemical diversity within Achillea species, positioning them as promising natural sources of antioxidants. Further exploration and selection of specific accessions within each species are crucial for unlocking their medicinal potential and supporting cultivation and conservation efforts.

Co-inoculation of mycorrhizal fungi and plant growth-promoting rhizobacteria improve growth, biochemical and physiological attributes in Dracocephalum kotschyi Boiss. under water deficit stress

Background

Because of swift climate change, drought is a primary environmental factor that substantially diminishes plant productivity. Furthermore, the increased use of chemical fertilizers has given rise to numerous environmental problems and health risks. Presently, there is a transition towards biofertilizers to enhance crops' yield, encompassing medicinal and aromatic varieties.

Methods

This study aimed to explore the impacts of plant growth-promoting rhizobacteria (PGPR), both independently and in conjunction with arbuscular mycorrhizal fungi (AMF), on various morphological, physiological, and phytochemical characteristics of Dracocephalum kotschyi Boiss. This experimentation took place under different irrigation conditions. The irrigation schemes encompassed well watering (WW), mild water stress (MWS), and severe water stress (SWS). The study evaluated the effects of various biofertilizers, including AMF, PGPR, and the combined application of both AMF and PGPR (AMF + PGPR), compared to a control group where no biofertilizers were applied.

Results

The findings of the study revealed that under water-stress conditions, the dry yield and relative water content of D. kotschyi Boiss. experienced a decline. However, the application of AMF, PGPR, and AMF + PGPR led to an enhancement in dry yield and relative water content compared to the control group. Among the treatments, the co-application of AMF and PGPR in plants subjected to well watering (WW) exhibited the tallest growth (65 cm), the highest leaf count (187), and the most elevated chlorophyll a (0.59 mg g-1 fw) and b (0.24 mg g-1 fw) content. Regarding essential oil production, the maximum content (1.29%) and yield (0.13 g plant -1) were obtained from mild water stress (MWS) treatment. The co-application of AMF and PGPR resulted in the highest essential oil content and yield (1.31% and 0.15 g plant-1, respectively). The analysis of D. kotschyi Boiss. essential oil identified twenty-six compounds, with major constituents including geranyl acetate (11.4-18.88%), alpha-pinene (9.33-15.08%), Bis (2-Ethylhexyl) phthalate (8.43-12.8%), neral (6.80-9.32%), geranial (9.23-11.91%), and limonene (5.56-9.12%). Notably, the highest content of geranyl acetate, geranial, limonene, and alpha-pinene was observed in plants subjected to MWS treatment following AMF + PGPR application. Furthermore, the co-application of AMF, PGPR, and severe water stress (SWS) notably increased the total soluble sugar (TSS) and proline content. In conclusion, the results indicate that the combined application of AMF and PGPR can effectively enhance the quantity and quality of essential oil in D. kotschyi Boiss., particularly when the plants are exposed to water deficit stress conditions.

Contribution of Serendipita indica on growth improvement, antioxidative capacity of Dracocephalum kotschyi, and its resistance against cadmium stress

Cadmium pollution is a severe issue worldwide which causes an elevated concern in agriculture. The utilization of plant-microbial interactions offers a promising approach for the remediation of cadmium-polluted soils. To elucidate the mechanism of Serendipita indica-mediated cadmium stress tolerance, a potting experiment was conducted to study the impact of S. indica on Dracocephalum kotschyi plants grown under different cadmium concentrations (0, 5, 10, and 20 mg/kg). The effects of cadmium and S. indica on plant growth, antioxidant enzyme activities, and accumulation of cadmium were investigated. The results showed that cadmium stress significantly decreases biomass, photosynthetic pigments, and carbohydrate content concomitantly with increasing antioxidant activities, electrolyte leakage, and hydrogen peroxide, proline, and cadmium content. Inoculation with S. indica alleviated the adverse effect of cadmium stress by enhancing shoot and root dry weight, photosynthetic pigments, and carbohydrate, proline, and catalase activity. Unlike cadmium stress, the presence of fungus led to a reduction in electrolyte leakage and hydrogen peroxide content as well as the content of cadmium in D. kotschyi leaf which mitigates cadmium-induced oxidative stress. Our findings demonstrated S. indica inoculation alleviates the adverse effects of cadmium stress in D. kotschyi plants which could prolong their survival under stressful conditions. Due to the importance of D. kotschyi and the effect of biomass increase on the amount of its medicinal substances, exploiting S. indica not only promotes plant growth, but also may be used as a potential eco-friendly method for relieving the phytotoxicity of Cd and remediating Cd-contaminated soil.

Antioxidant and Anti-Inflammatory Activities of Phenolic Acid-Rich Extract from Hairy Roots of Dracocephalum moldavica

This study evaluates the antioxidant properties and anti-inflammatory potential of polyphenolic acid-rich fractions of 80% methanolic extract from the hairy roots of Dracocephalum moldavica. The fractionation of the crude extract yielded the following: a diethyl ether fraction rich in caffeic acid (DM1) (25.85 mg/g DWE), an n-butyl fraction rich in rosmarinic acid (DM3) (43.94 mg/g DWE) and a water residue rich in salvianolic acid B (DM4) (51.46 mg/g DWE). The content of these compounds was determined using high-performance liquid chromatography (HPLC). Their antioxidant activity was evaluated based on DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt) and FRAP assays. The anti-inflammatory activity of the fractions was determined by their effect on nuclear factor kappa-B (NF-κB) activation and interleukin-1β (IL-1β) production in LPS E. coli stimulated monocytes. The level of pro-inflammatory IL-1β in cells was measured using ELISA. The activation of NF-κB in THP1-Blue™ cells, resulting in the secretion of SEAP (secreted embryonic alkaline phosphatase), was detected spectrophotometrically using Quanti-Blue reagent. Among the tested fractions, the diethyl ether fraction (DM1) showed the highest antioxidant potential, with an EC50 value of 15.41 µg/mL in the DPPH assay and 11.47 µg/mL in ABTS and a reduction potential of 10.9 mM Fe(II)/g DWE in FRAP. DM1 at a concentration of 10 mg/mL also efficiently reduced LPS-induced SEAP secretion (53% inhibition) and IL-1β production (47% inhibition) without affecting the normal growth of L929 fibroblast cells.

Synergistic effects of calcium and melatonin on physiological and phytochemical attributes of Dracocephalum kotschyi genotypes under salinity stress

Since regulatory roles of calcium (Ca) and melatonin (MT) in physiological responses of plants to salinity stress are lacking, various Dracocephalum kotschyi genotypes (Bojnord, Urmia, Fereydunshahr, and Semirom) were pretreated with exogenous Ca (5 mM), MT (100 μM), and Ca + MT in the presence of salt (75 mM NaCl). In addition measuring the concentration of phenolic compounds by high performance liquid chromatography (HPLC), histochemical evaluations of essential oils and phenolic compounds in glandular trichomes of leaf samples were performed by light microscope. Salt stress reduced shoot fresh (SFW) and dry weight (SDW), leaf area (LA), relative water content (RWC), and maximum efficiency of photosystem II (F_v /F_m ), but enhanced total phenolic content (TPC) and total flavonoids content (TFC), phenolic compounds concentrations, DPPH radical scavenging capacity, electrolyte leakage (EL), proline and hydrogen peroxide (H₂ O₂ ) concentrations, and Na⁺ /K⁺ and essential oils and TPC of the glandular trichomes of leaves in all D. kotschyi genotypes. Foliar spraying of Ca, MT, and particularly Ca + MT on D. kotschyi seedlings improved SFW, SDW, RWC, TPC, TFC, proline and phenolic compounds concentrations, F_v /F_m , and DPPH radical scavenging capacity, but reduced H₂ O₂ , EL, and Na⁺ /K⁺ in the leaves and essential oils and TPC in the glandular trichomes of all genotypes under both non-stress and salt stress conditions. These findings indicate that the crosstalk between MT and Ca synergistically improves salt tolerance, TPC and TFC, phenolic compounds concentration, and essential oils accumulation in glandular trichomes of different D. kotschyi genotypes.

Underutilized Plant Cymbopogan martinii Derived Essential Oil Is Excellent Source of Bioactives with Diverse Biological Activities

Cymbopogan martinii, also known as Palmarosa, is an underutilized plant of tropical region. Due to outstanding antioxidant potential it has been used as a part of conventional medicine and beauty product. Regardless of its importance, complete pharmacological and phytochemical studies are still in its early stages. In the current study, Palmarosa essential oil (PRO) was extracted from Cymbopogan martinii and was evaluated for its phytochemicals, antimicrobial and antifungal, anti-inflammatory and anti-diabetic and protection from UV rays. Oil from fresh leaves was extracted and analysed for presence of phytochemicals (Tannin, Flavonoids, and Phenolics). Various antioxidant activities like DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid), Nitric oxide radical, Hydroxyl radical, iron reducing, iron cheating activity were performed. Antibacterial, anti-inflammatory, Antidiabetic, membrane integrity assay, and UV-absorption assay was also performed. Antifungal activity against "Aspergillosis" and "Mucormycosis" causing fungal strains was also evaluated. High concentration of polyphenolics like Tannin, Flavonoid, phenolics were revealed through phytochemical analysis. GC-FID revealed the presence of Geraniol, major component of Palmarosa oil and other bioactive compound in PRO. PRO showed high anti-inflammatory and anti-diabetic potential and can be used as an Antidiabetic agent due to inhibitory effect on α-amylase activity. Further study revealed that PRO inhibits α-amylase in competitive manner. Hence from the results obtained it is confirmed that the PRO possesses considerable amount of bioactive compounds and can be used in pharmaceutical, food and cosmetic industries.

Caucasian Dragonheads: Phenolic Compounds, Polysaccharides, and Bioactivity of Dracocephalum austriacum and Dracocephalum botryoides

Dracocephalum botryoides Steven and Dracocephalum austriacum L. are unexplored species of the Dracocephalum genus (Lamiaceae family) with a distribution in the Caucasus, where they are used in folk medicine and local cuisine. There are no data on the chemical composition of these Dracocephalum species. In this study, the application of a liquid chromatography-mass spectrometry technique for the metabolite profiling of methanol extracts from herbs and roots of D. austriacum and D. botryoides resulted in the identification of 50 compounds, including benzoic acid derivatives, phenylpropanoids, flavonoids and lignans. Water-soluble polysaccharides of the herbs and roots of D. austriacum and D. botryoides were isolated and characterized as mostly pectins with additive arabinogalactan-protein complexes and starch-like compounds. The antioxidant potential of the studied extracts of Dracocephalum and selected phenolics and water-soluble polysaccharides were investigated via radical-scavenging and ferrous (II) ion chelating assays. This paper demonstrates that herbs and roots of D. austriacum and D. botryoides are rich sources of metabolites and could be valuable plants for new biologically active products. To the best of our knowledge, this is the first study of whole plant metabolites and their antioxidant activity in D. austriacum and D. botryoides.

Diversity and Distribution Patterns of Endemic Medicinal and Aromatic Plants of Iran: Implications for Conservation and Habitat Management

Iran, with its unique climatic and topographic conditions, is home to about 8200 species of vascular plants. Approximately 2300 of the 8200 species are popularly characterized as medicinal or aromatic. Here, we compile information about the endemic medicinal and aromatic plants (MAPs) of Iran and map their distributions. Our survey found 180 endemic species of MAPs, belonging to 10 families and 30 genera. The majority of species are found in Lamiaceae, Fabaceae, and Apiaceae, with 86, 30, and 18 species, respectively. Approximately 70% of these plants have been recorded in the 10 provinces of Esfahan, Kerman, Fars, Tehran, Chaharmahal va Bakhtiari, East Azarbaijan, Lorestan, West Azarbaijan, Hamadan, and Mazandaran. These provinces are located in the Iran-o-Turanian region, one of the three major phytogeographic regions in Iran, which covers five areas of endemism (i.e., Azarbaijan, Zagros, Kopet Dagh-Khorassan, Alborz, and Central Alborz). So, Iran-o-Turanian region is the main center of diversity for the Iranian endemic MAPs. The north, center and western parts of Iran are rich in MAPs and could be considered as the dominant biodiversity hotspots of Iran more seemingly due to the diverse climatic and geographic assortment which generates the highest frequency and distribution of MAPs. Many of these MAPs are at the edge of extinction due to the unwise, unscientific harvesting and/or global climate change. Therefore, there is an urgent need to conserve and propagate some of these important MAPs to save them from extinction and also to ensure the availability of raw materials for their use and future research into their efficacy. Furthermore, identifying the areas of endemism (AEs) is an essential part of ongoing regional conservation management programs in Iran and worldwide.

Plants from Genus Dracocephalum in Iran: Pharmacology and Phytochemistry Overview

BACKGROUND

Genus Dracocephalum belongs to the Lamiaceae family, representing 11 species in Iran, containing D. ghahremanii Jamzad, D. lindbergii Rech. F, D. oligadenium Bornm. & Gauba, D. kotschyi Boiss., D.multicaule, D.Aucheri, D.Subcapitatum, D.Thymifolium, D.Moldavica, D. polychaetum Borm, and D. surmandinum Rech.f. The current study aimed to investigate the morphological and phytochemical properties of Dracocephalum species in Iran and their pharmacological effects.

METHODS

The search was restricted to scientific articles from PubMed, Google Scholar, Science Direct, SpringerLink, and Scopus. The search was limited to scientific journals, books, and book chapters focusing on the medicinal properties of Dracocephalum in Iran for the era from 1993 to 2020.

RESULTS

Findings show that Dracocephalum species were utilized to treat various disorders in traditional medicine. Phytochemical studies show that the main constituents isolated from the plant consist of lignans, phytosterol, flavonoids, phenols, alkaloids, Sesquiterpenes, and oxygenated and hydro carbonated monoterpenes. These main components are responsible for antihyperlipidemic, antimicrobial, anticancer, antispasmodic, antioxidant, and cardiovascular effects of the plant.

CONCLUSION

This plant has a good potential for drug discovery and curing different diseases. Therefore, more research will be done on the Iranian species of Dracocephalum based on clinical and animal studies to develop an effective drug formulation.

Evaluation of Antibacterial Synergism of Methanolic Extract of Dracocephalum kotschyi and Trachyspermum ammi

BACKGROUND

Chemical preservatives are now used in various foods to increase shelf life and maintain quality instead of its natural extracts with anti-bacterial properties from plants can be used. Hence this research was planned to evaluate and study the synergistic antibacterial effect of the methanolic extracts of Dracocephalum kotschyi (D. kotschyi) and Trachyspermum ammi (T. ammi) against standard pathogenic bacteria like: Pseudomonas aeruginosa (P. aeruginosa), Shigella dysenteriae (S. dysenteriae), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

METHODS

The methanolic extract of D. kotschyi and T. ammi was prepared by the Soxhlet method. The minimum inhibitory concentration (MIC) of this methanolic extracts were determined by the microdilution method. Thus, by determining the amount of fractional inhibitory concentration index (FICI), the interaction between the methanolic extracts of D. kotschyi and T. ammi on the pathogenic bacteria was determined.

RESULTS

In this study, the MIC of the extracts of D. kotschyi and T. ammi on the pathogen; S. aureus was equal to 6.25 mg/mL and 12.5 mg/mL for S. dysenteriae, E. coli and P. aeruginosa. Hence, the combination of methanolic extracts of these plants shows a synergistic antibacterial effect (FICI < 0.5), on all tested pathogenic microorganisms was proved.

CONCLUSION

Due to the antimicrobial synergistic effect and cost-effective production process of methanolic extracts of D. kotschyi and T. ammi, they are used as natural preservatives and flavouring agents to preserve foods.

Evaluation of antioxidant potential of Heliotropium bacciferum Forssk extract and wound healing activity of its topical formulation in rat

Wound healing is a dynamic process that occurs in the tissue under the skin. During this process, oxidative stress biomarkers are excessively produced, which finally lead to inflammation and cellular damage. In this study, efforts have been made to evaluate the antioxidant effect and wound healing activity topical formulation containing Heliotropium bacciferum Forssk extract. The in vitro antioxidant properties were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities and the ferric reducing antioxidant power (FRAP) assay. The herbal ointments (2.5% w/w and 5% w/w) were prepared from the hydroalcoholic extract of H. bacciferum Forssk and administrated on the induced wounds in Wistar rats. The chromatic assay, percentage of wound contraction, and histopathological studies were used for evaluating the wound healing activity. For the evaluation of reactive oxygen species (ROS), catalase (CAT) activity, superoxide dismutase (SOD), and glutathione (GSH) levels were examined. The DPPH method showed tremendous radical scavenging activities at the corresponding concentrations with EC₅₀ value of 80μg/mL. Topical application of the ointment (5% w/w) showed the highest wound contraction in comparison to the positive control (treated with CICALFATE™) and the control group (treated with normal saline). Similarly, the histological study of the group treated with the extract ointment (5% w/w) showed full collagen tissue deposition with a complete epidermal regeneration. The results of the assessment of GSH levels as well as CAT and SOD activities in the treated group (5% w/w) confirmed the scavenging property of the extract ointment. Our findings indicated the proper wound healing impact of the topical formulation of H. bacciferum Forssk due to its notable antioxidant capacity.

Toward understanding of the methoxylated flavonoid biosynthesis pathway in Dracocephalum kotschyi Boiss

Nowadays, with the development and advancement of next-generation sequencing technologies, a new path has been provided for transcriptomic studies. In this study, the transcriptome of Dracocephalum kotschyi Boiss., as an endemic and endangered plant which is contained a large amount of valuable secondary metabolites with antioxidant and anticancer properties, was sequenced. Then functional annotation and gene ontology analysis for 165,597 assembled transcripts were performed, most were associated with the metabolic pathways. This might be because there are various active biochemical pathways in this plant. Furthermore, after comprehensive transcript annotation, the putative genes involved in the main metabolic pathways of D. kotschyi were identified. Then, the biosynthetic pathway of its valuable methoxylated flavones was proposed. Finally, the accumulations of important methoxylated-flavone metabolites in three different tissues were quantified by HPLC. The relative expression of the genes involved in the proposed pathway was investigated by qRT-PCR, which indicated high expression levels in the bud tissue. The present results may lead to the design strategies to preserve the genetic diversity of endangered D. kotschyi plants and apply the new methods for engineering its valuable methoxylated-flavones pathway.

Relationships of irrigation water and soil physical and chemical characteristics with yield, chemical composition and antimicrobial activity of Damask rose essential oil

Damask rose (Rosa damascena Mill.) is an aromatic medicinal plant rich in bioactive compounds with high value in the food, pharmaceutical and cosmetic industries. Knowledge of the factors affecting the quantitative and qualitative properties of the compounds in its essential oil (EO) and the bioactivity of this EO is important in optimizing Damask rose cultivation and production. This research studied, for the first time, the effects of irrigation water and soil chemical and physical characteristics on the EO yield of this important commercial species and on it chemical composition and antimicrobial activity. The results showed the significant effect of crop cultivation site on yield, chemical composition and inhibition zone diameter (IZD) at the 1% significance level. The highest EO yield (~0.0266%), which belonged to the Noushabad site (EON), resulted from the increased soil electrical conductivity (EC) and the higher sand, gypsum and lime contents and irrigation water salinity. Analysis of the chemical composition of the EOs showed that their main compounds at all three crop sites were citronellol, nonadecane, heneicosane and geraniol. The EO obtained from the Yazdel site (EOY) had the highest contents of citronellol and geraniol (~29.05% and ~6.85%) that were directly correlated with soil potassium and phosphorus contents and inversely correlated with soil acidity and EC and its lime, nitrogen, and organic carbon contents. Antimicrobial assays indicated that the EO extracted from the Sefidshahr site (EOS), which had the largest inhibition zone diameter (~14.67 mm) for Aspergillus brasiliensis (IZD~14.67 mm) and the lowest MIC (~31.25 μg/mL) for Staphylococcus aureus and Pseudomonas aeruginosa, exhibited efficacy similar to that of rifampin, probably due to the dominance of the alkanes in it. The EOY and EOS also exhibited the strongest inhibitory and lethal activity against Candida albicans (MIC and MBC <15.63 μg/mL for EOY and MIC and MBC = 62.5 μg/mL for EOS), which were six and four times stronger than those of nystatin, respectively. Therefore, the selected EOs can act as a potentially promising strategy for fighting microbial strains.

Chemotype of damask rose with oleic acid (9 octadecenoic acid) and its antimicrobial effectiveness

Essential oils are natural products that have great antimicrobial potential value against many fungi and bacteria. Rosa damascena Mill. is one of the most important aromatic species of the Rosaceae family from which essential oil and economically valuable products can be obtained. The present study was designed to investigate the major compositions of the essential oil of this plant in Isfahan region of Iran and to identify its antibacterial and antifungal effects against 11 microorganisms causing human diseases and food spoilage. The essential oil was extracted by using the Clevenger apparatus and was analyzed by gas chromatography-mass spectrometry (GC-MS) technique. Its antimicrobial activity was evaluated by well diffusion, minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC). The results showed that the most important compounds of the essential oil were nonadecane (24.72%), heneicosane (19.325%), oleic acid (17.63%), and citronellol (12.61%). The results also showed that the highest inhibition zone of rose essential oil was against Aspergillus brasiliensis (15.00 ± 0.00 mm) and had a significant effect on Klebsiella pneumoniae (~ 8.00 mm). Also the rose oil had a significant inhibition and lethal effect against Candida albicans (MIC and MBC ~ 125 μg/mL), which is equivalent to the nystatin antibiotic (~ 125 μg/mL). Therefore, the essential oil of Damask rose can be considered as an alternative natural product for the prevention and treatment of fungal diseases in humans and against food spoilage as well.

Extraction of essential oil from Dracocephalum kotschyi Boiss. (Lamiaceae), identification of two active compounds and evaluation of the antimicrobial properties

ETHNOPHARMACOLOGICAL RELEVANCE

Dracocephalum kotschyi is a medicinal plant widely used in traditional medicine to treat pain, fever, inflammation, and seizures.

AIM OF THE STUDY

Due to the importance of this plant and the well-known antibacterial activity of essential oils, the aim of the present study was to investigate the composition of essential oil and evaluate the antimicrobial activity of its main active compounds.

MATERIALS AND METHODS

In order to test its possible application at industrial level the oil was extract from the cultivated and wild plants. The epigean parts were collected in June 2018 from the same region of Daran (Isfahan, Iran). The extraction of essential oil was carried out using a Clevenger apparatus. The composition of the essential oil was assayed by using a gas chromatography/mass spectroscopy apparatus (GC/MS).

RESULTS

Results showed that the predominant compounds of essential oil of cultivated plants were α-pinene (13.66%), (E)-citral (12.89%), neral (11.25%), methyl geranate (8.66%), limonene (8.33%), campholenal (6.22%) and geraniol (5.69%), while those found in naturally grown plants were two main compounds: cyclohexylallene (52.63%) and limonene (35.88%). The antimicrobial properties of the plant were determined against 12 strains of microorganism by evaluating inhibition halo, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The highest inhibition halo for both oils from cultivated and wild plants was obtained against Aspergillus brasiliensis. The MIC value against Gram-positive Bacillus subtilis was 31.25 μg/ml, it was the lowest value provided by the essential oil obtained from the cultivated sample, the MIC was significantly lower than that obtained by treating the same strain with Rifampin. On the other hand, Candida albicans had the highest sensitivity (MIC value of 31.25 μg/ml) for the essential oil obtained from wild plants as the inhibitory concentration was lower than that obtained treating the yeast with Nystatin.

CONCLUSIONS

Therefore, according to the results of the present study, the use of the essential oil obtained from D. kotschyi can be used to protect food and to treat microbial infections.

Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

Chemical composition and antimicrobial activity of essential oils obtained from leaves and flowers of Salvia hydrangea DC. ex Benth

The majority of essential oils obtained from vascular plants have been demonstrated to be effective in treating fungal and bacterial infections. Among others, Salvia hydrangea is an endemic half-shrub belonging to the Lamiaceae family that has been widely used from ancient times in Iranian traditional medicine. The aim of this study was to compare the composition and antimicrobial properties of essential oils obtained from leaves or flowers of this plant, collected from the Daran region of Iran during June 2018. The oils were obtained using Clevenger apparatus, their composition was evaluated by means of gas chromatography/mass spectrometry (GC/MS) and the antimicrobial properties were assayed by measuring inhibition halos, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The yield of leaf oil was ~ 0.25% and that of flower oil was ~ 0.28%. Oil composition was affected by the part of the plants used: the most abundant bioactives contained in leaf essential oil were (+)-spathulenol (16.07%), 1,8-cineole (13.96%), trans-caryophyllene (9.58%), β-pinene (8.91%) and β-eudesmol (5.33%) and those in flower essential oil were caryophyllene oxide (35.47%), 1,8-cineole (9.54%), trans-caryophyllene (6.36%), β-eudesmol (4.11%), caryophyllenol-II (3.46%) and camphor (3.33%). Both the oils showed a significant inhibitory and lethal effect on the Gram-negative bacteria Pseudomonas aeruginosa (MIC ~ 16 µg/mL), Shigella dysenteriae and Klebsiella pneumoniae (MIC ~ 62 µg/mL). Therefore, the essential oils obtained from both leaves and flowers of S. hydrangea may have potential application as bactericidal agents against some bacteria.