Elsholtzia Densa Research Articles

Bioactivities of essential oil extracted from Elsholtzia densa Benth. And its main components against Tribolium castaneum eggs and pupae

This study aimed to develop a relatively natural and safe botanical insecticide for controlling the storage pest Tribolium castaneum in the egg and pupal stages. It examined how Elsholtzia densa Benth. essential oil (EO) and its primary components, β-caryophyllene and limonene, affected T. castaneum eggs and pupae through contact and fumigation. Among th, the contact activities of β-caryophyllene against T. castaneum eggs and pupae are LD50 (median lethal dose, 50%) = 0.156 mg/cm2 and ED50 (median effective dose, 50%) = 16.35 mg/pupa respectively. The study also investigated the effect of β-caryophyllene and limonene on T. castaneum eggs and pupae through synergistic contact and fumigation. When the mixing ratio of β-caryophyllene and limonene was 7:1, the LD50 value of contact activity against T. castaneum eggs was reduced to 0.100 mg/cm2, displaying an obvious synergistic effect. Experiments were conducted to investigate the antitoxic effect of β-caryophyllene on T. castaneum eggs and pupae, as well as its effects on the enzymatic activity of acetylcholinesterase, succinate dehydrogenase, glutathione S-transferase and carboxylesterase in T. castaneum pupae. Finally, the molecular docking techniques were employed to confirm the aforementioned effects on enzyme function. The findings of this study might help improve storage pest control with T. castaneum and create eco-friendly insecticides using E. densa EO, β-caryophyllene, and limonene.

Comparative Analysis of Plastomes in Elsholtzieae: Phylogenetic Relationships and Potential Molecular Markers.

The Elsholtzieae, comprising ca. 7 genera and 70 species, is a small tribe of Lamiaceae (mint family). Members of Elsholtzieae are of high medicinal, aromatic, culinary, and ornamentals value. Despite the rich diversity and value of Elsholtzieae, few molecular markers or plastomes are available for phylogenetics. In the present study, we employed high-throughput sequencing to assemble two Mosla plastomes, M. dianthera and M. scabra, for the first time, and compared with other plastomes of Elsholtzieae. The plastomes of Elsholtzieae exhibited a quadripartite structure, ranging in size from 148,288 bp to 152,602 bp. Excepting the absence of the pseudogene rps19 in Elsholtzia densa, the exhaustive tally revealed the presence of 132 genes (113 unique genes). Among these, 85 protein-coding genes (CDS), 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (rps19 and ycf1) were annotated. Comparative analyses showed that the plastomes of these species have minor variations at the gene level. Notably, the E. eriostchya plastid genome exhibited increased GC content regions in the LSC and SSC, resulting in an increased overall GC content of the entire plastid genome. The E. densa plastid genome displayed modified boundaries due to inverted repeat (IR) contraction. The sequences of CDS and intergenic regions (IGS) with elevated variability were identified as potential molecular markers for taxonomic inquiries within Elsholtzieae. Phylogenetic analysis indicated that four genera formed monophyletic entities, with Mosla and Perilla forming a sister clade. This clade was, in turn, sister to Collinsonia, collectively forming a sister group to Elsholtzia. Both CDS, and CDS + IGS could construct a phylogenetic tree with stronger support. These findings facilitate species identification and DNA barcoding investigations in Elsholtzieae and provide a foundation for further exploration and resource utilization within this tribe.

Study on the control potential of Alternaria alternata against four species of weeds in agricultural fields on the Tibetan Plateau

ABSTRACT The aim of this study was to investigate the potential and pathogenic mechanism of the pathogenic fungus Alternaria alternata strain GD-011-B against four major agricultural weeds on the Tibetan plateau, and to lay a foundation for the commercial production and application of this strain. The mycelial masses had herbicidal activity against the isolated leaves of the weeds Chenopodium album, Elsholtzia densa, Malva verticillata, and Amaranthus retroflexus L., with a descending herbicidal activity order of M. verticillata > E. densa > A. retroflexus > C. album. The fermentation broth also showed herbicidal activity by treating the whole plants of these four weeds in the descending order of C. album > E. densa > M. verticillata > A. retroflexus. Scanning electron microscopy revealed that GD-011-B mycelia invaded the inner part of the leaf of A. retroflexus through the stomata and epidermal tissue gap and extended to the back, damaging the leaf epidermis and tissues and sporulating on the leaf surface, ultimately resulting in leaf disease. The fermentation broth of pathogen GD-011-B was not pathogenic to Vicia faba L., Pisum sativum L., Hordeum vulgare L., or Triticum aestivum L., but it was slightly pathogenic to Brassica napus L. Therefore, Alternaria alternata can be used as a herbicidal microorganism with high potential for biological control of four major agricultural weeds on the Tibetan plateau.

Screening, identification, and observation of infection process of a herbicidal fungal strain HY‐02

AbstractThis study clarified the herbicidal activity, crop safety, classification status, and infection process of herbicidal strain HY‐02, and laid a foundation for its development and utilization. Strain HY‐02 was isolated from the leaves of Rumex patientia L. by the tissue isolation method. The pathogenicity of the strain to six broadleaf weeds and the safety for four common crops were determined by spray inoculation. The taxonomic status of HY‐02 was determined by morphology and molecular biology, and the infection process was confirmed by scanning electron microscopy. In vitro leaf experiments showed that strain HY‐02 was pathogenic to six broadleaf weeds, Polygonum aviculare L., Elsholtzia densa Benth., Chenopodium album L., Polygonum lapathifolium L., Amaranthus retroflexus L., and Malva verticillata L. The pot experiment of weeds found that the pathogenicity rates for P. aviculare, E. densa, C. album, P. lapathifolium, A. retroflexus, and M. verticillata were 100.00%, 94.44%, 95.24%, 83.33%, 73.02%, and 40.00%, respectively. Strain HY‐02 seemed safe for four crops (Hordeum vulgare L., Triticum aestivum L., Vicia faba L., and Pisum sativum L.), but not for Brassica napus L. The strain was identified as Alternaria alternata (Fries) Keissler. Scanning electron microscope observations showed that hyphae invaded leaf tissues from the stomata by destroying epidermal cells. Hyphae rapidly grew and invaded living tissues by obtaining nutrients from the tissues, destroying the whole leaf tissues, and finally forming reticular lesions. Therefore, the HY‐02 strain has the potential to be developed into microbial biocontrol agents for weed control.

Evaluation of the biocontrol potential of the fungus Botrytis euroamericana strain HZ-011 for herbicidal activity

BackgroundWeeds in farmland seriously threaten crop yield and cause huge economic losses. Due to the extensive use of chemical herbicides, a series of problems have been arisen, such as environmental pollution, soil degradation and pesticide residues. To assess the herbicidal activity, crop safety, taxonomic identity and infection process of strain HZ-011, the methods of inoculation on detached leaves in vitro and pot plants in vivo, as well as scanning electron microscopy, were used in this study.ResultsThe results indicated that strain HZ-011 had pathogenic effects on detached leaves of four weeds, including Amaranthus retroflexus Linn., Elsholtzia densa Benth., Malva crispa Linn. and Chenopodium album Linn. in vitro. Strain HZ-011 also showed high pathogenicity to C. album and A. retroflexus in vivo, in which the pathogenicity rates were 100%, meaning all plants died after 7 days in the pot test, while the pathogenicity rates for E. splendens and M. crispa were 60.00 and 29.60%, respectively. This strain was safe for local crops, including Vicia faba Linn., Pisum sativum Linn., Brassica napus Linn., Hordeum vulgare Linn. and Triticum aestivum Linn. Strain HZ-011 was identified as the fungus Botrytis euroamericana based on its morphology, molecular biology and a constructed phylogenetic tree. The infection process of B. euroamericana HZ-011 in C. album was studied by plant histopathological observations after pathogen infection. This procedure showed that the mycelium of strain HZ-011 invaded C. album tissues from the stomata, infected and propagated within the tissues, and the spores produced further damage in the C. album tissues and lesions occurred on the surfaces of C. album leaves.ConclusionThese tests provide a basis for fungus B. euroamericana HZ-011 as a potential microbial herbicide.

The competitive strategies of poisonous weeds Elsholtzia densa Benth. on the Qinghai Tibet Plateau: Allelopathy and improving soil environment.

The competitive strategies of plants play a crucial role in their growth. Allelopathy is one of the weapons that plants use to improve their competitive advantage. In order to explore the competitive strategy of a poisonous weed Elsholtzia densa Benth. (E. densa) on the Qinghai-Tibet Plateau (QTP), the effects of decomposing substances of E. densa on growth, root border cells (RBCs) characteristics of highland crop highland barley (Hordeum vulgare L.), and soil environment were determined. The decomposing allelopathic effect of E. densa on the germination and seedling growth of highland barley mainly occurred in the early stage of decomposing. The allelopathic effects were mainly on seed germination and root growth of highland barley. After treatment with its decomposing solution, the RBC's mucilage layer of highland barley thickened, and the RBC's activity decreased or even apoptosis compared with the control. However, only the above-ground part of the treatment group showed a significant difference. The effects of E. densa decomposed substances on the soil environment were evaluated from soil physicochemical properties and bacterial community. The results showed that soil bacteria varied greatly in the early stage of decomposion under different concentrations of E. densa. In addition, E. densa decomposing substances increased the soil nutrient content, extracellular enzyme activities, and bacterial community diversity. In the process of decomposition, the bacterial community structure changed constantly, but Actinobacteriota was always the dominant phylum. These results indicated that E. densa might adopt the following two strategies to help it gain an advantage in the competition: 1. Release allelochemicals that interfere with the defense function of surrounding plants and directly inhibit the growth and development of surrounding plants. 2. By changing the physical and chemical properties of soil and extracellular enzyme activity, residual plant decomposition can stimulate soil microbial activity, improve soil nutrition status, and create a more suitable soil environment for growth.

Two new compounds from the aerial parts of Elsholtzia densa

Two new compounds, named edensa acid ( 1 ), and edensaoside A ( 2 ), as well as twenty-nine known compounds ( 3–31 ) were isolated from the aerial parts of Elsholtzia densa Benth. The chemical structures of the new compounds were determined by spectrometric data interpretation using NMR, HRESIMS, IR and UV spectroscopy. In addition, all compounds were evaluated for their anti-influenza virus activities against A/WSN/33(H1N1). Among these, compounds 18 and 19 exhibited moderate anti-influenza virus activities with IC 50 values of 18.79 μ M and 59.87 μ M respectively. • Two new and twenty-nine known compounds were isolated from the aerial parts of Elsholtzia densa Benth. • Structures were elucidated by spectroscopic analysis. • Compounds were evaluated for their anti-influenza A virus activities.

Chemical Constituents of Six Fractions Separated by Column Chromatography of Essential Oil Extracted from Elsholtzia Densa and Their Acute Toxicity Against Two Stored-Product Insects

Chemical Constituents of Six Fractions Separated by Column Chromatography of Essential Oil Extracted from Elsholtzia Densa and Their Acute Toxicity Against Two Stored-Product Insects

Chemical Constituents of the Essential Oil Extracted from Elsholtzia densa and Their Insecticidal Activity against Tribolium castaneum and Lasioderma serricorne.

Storage pests pose a great threat to global food security. Here, we found that the essential oil (EO) extracted from E. densa possesses obvious effects against the insects that threaten stored-products. In this work, we investigated the chemical constituents of the essential oil extracted from Elsholtzia densa, and their insecticidal (contact and fumigant) toxicity against Tribolium castaneum and Lasioderma serricorne. A total of 45 compounds were identified by GC-MS, accounting for 98.74% of the total EO. Meanwhile, 11 compounds were isolated from the EO, including limonene, β-caryophyllene, ρ-cymene, trans-phytol, α-terpineol, linalool, acetophenone, 1,8-cineole, ρ-cymen-7-ol, 1-O-cerotoylgly-cerol, and palmitic acid. Furthermore, acetophenone, ρ-cymen-7-ol, and 1-O-cerotoylgly-cerol were isolated for the first time from Elsholtzia spp. The results of the bioassays indicated that the EO had the property of insecticidal toxicity against T. castaneum and L. serricorne. All of the compounds showed different levels of insecticidal toxicity against the two species of insects. Among them, 2-ethyl-1H-imidazole had no insecticidal toxicity against T. castaneum, but possessed fumigant and obvious contact toxicity against L. serricorne. ρ-Cymen-7-ol had beneficial insecticidal toxicity against the two species of insects, and fumigant toxicity against L. serricorne. ρ-Cymen-7-ol (LD50 = 13.30 μg/adult), 1-octen-3-ol (LD50 = 13.52 μg/adult), and 3-octanol (LD50 = 17.45 μg/adult) showed significant contact toxicity against T. castaneum. Acetophenone (LD50 = 7.07 μg/adult) and ρ-cymen-7-ol (LD50 = 8.42 μg/adult) showed strong contact toxicity against L. serricorne. ρ-Cymene (LC50 = 10.91 mg/L air) and ρ-cymen-7-ol (LC50 = 10.47 mg/L air) showed powerful fumigant toxicity to T. castaneum. Limonene (LC50 = 5.56 mg/L air), acetophenone (LC50 = 5.47 mg/L air), and 3-octanol (LC50 = 5.05 mg/L air) showed obvious fumigant toxicity against L. serricorne. In addition, the EO and its chemical compounds possessed different levels of repellent activity. This work provides some evidence of the value of exploring these materials for insecticidal activity, for human health purposes. We suggest that the EO extracted from E. densa may have the potential to be developed as an insecticidal agent against stored product insect pests.

New Contributions to the Flora of Beijing, China

Plant diversity is the basis of human survival and development. Beijing, the capital of China, has been experiencing rapid urbanization and development, and the conservation of its biodiversity is being threatened. It is urgent to strengthen the survey of biodiversity in order to take more effective measures for protection. To evaluate the current state of plant diversity in Beijing, we carried out a large-scale field investigation in the last ten years. The line-transect and quadrat methods were used, with the regional grid (10 km×10 km) as a survey unit. In this paper, new forms of three plant species with white flowers are described, namely,<i> Gentiana macrophylla</i> f. <i>alba</i> (Gentianaceae), <i>Pedicularis spicata</i> f. <i>alba </i>(Orobanchaceae), and<i> Elsholtzia densa</i> f. <i>alba </i>(Lamiaceae). They are all important ornamental plant resources. In addition, four newly recorded species from Beijing, including <i>Aleuritopteris grisea</i>, <i>Polypodium sibiricum</i>, <i>Androsace incana</i>, and <i>Sida spinosa</i>, are discussed. This study provides an important contribution to the flora of Beijing. The results show that Beijing has a relatively rich and complex flora in North China. With increased field expeditions, more new records will be discovered. It is noteworthy that the number of alien invasive species shows a sustained increasing trend. They may have harmful impacts on the local ecosystem, and should be paid particular attention in the future researches.

The complete chloroplast genome of Elsholtzia densa var. ianthina (Lamiaceae)

Elsholtzia densa var. ianthina has important medicinal valve and is used as Tibetan medicine. The complete chloroplast genome of E. densa var. ianthina was assembled from Illumina pair-end sequence reads. The whole plastome is 149,118 bp in length and presents a quadripartite structure consisting of two copies of inverted repeat (IR) regions (25,167) separated by a large single copy (LSC) region (81,411 bp) and a small single copy (SSC) region (17,373 bp). The plastome of E. densa var. ianthina encodes a total of 130 genes, including 85 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The overall GC content of E. densa var. ianthina plastome is 37.9%. A maximum likelihood (ML) phylogenetic analysis revealed that E. densa var. ianthina was related to Elsholtziasplendens.

Biological weed control using Trichoderma polysporum strain HZ-31

To develop a potential bio herbicide, herbicide activity and crop safety of fungal strain HZ-31 isolated from naturally infected weed Cirsium arvense (L.) Scop. were investigated. The study was conducted in vitro and in vivo during the summers of 2017 and 2018. Strain HZ-31 showed broad-spectrum herbicidal activity, both in vitro and in vivo, when targeting Elsholtzia densa Benth., Polygonum lapathifolium L., Lepyrodiclis holosteoides (C.A. Mey.) Fenzl ex Fisch. & C.A. Mey., Avena fatua L., Chenopodium album L. and Polygonum aviculare L. Exposure to HZ-31 in vitro induced heavy levels of damage in the leaves of E. densa, A. fatua, and P. aviculare. Exposure to HZ-31 in vivo resulted in high mortality in E. densa, A. fatua, and P. lapathifolium. Although the exposure of various weeds to HZ-31 caused severe damage, the strain did not cause any deleterious effects in Vicia faba L. and Pisum sativum L., two of the five crops tested. Our results suggest that fungal strain HZ-31 could be a potential mycoherbicide candidate for weed control in V. faba and P. sativum fields. Based on its morphological characteristics and ITS nucleotide sequence analysis, the fungus was classified as Trichoderma polysporum (Louk:Fr.) Rifai. New perspectives for weeds control by T. polysporum and its use in V. faba and P. sativum crops were prospected, considering the bioherbicide selectivity described in this study.

The complete chloroplast genome sequence of Elsholtzia densa, a herb with volatile aroma component

The complete chloroplast genome sequence of Elsholtzia densa was analysed. The results indicated that the size of the chloroplast genome was 149,095 bp in length with a large single-copy region (LSC) of 81,497 bp, a small single-copy region (SSC) of 17,364 bp, and a pair of inverted repeat (IR) regions of 25,117bp. The overall GC content of the cpDNA genome was 37.86%, while the corresponding values of the LSC, SSC, and IR regions were 35.96%, 31.92%, and 43.16%, respectively. A total of 132 functional genes were identified, including 84 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The maximum likelihood phylogenetic tree suggested that E. densa was closely related to the species in the family Labiatae.

Composition and acaricidal activity of essential oil from Elsholtzia densa Benth against Sarcoptes scabiei mites in vitro

Plant-based natural products represent an alternative to chemical compounds for the control of mites in veterinary medicine. Here, the essential oil of Elsholtzia densa (E. densa) Benth was extracted using hydrodistillation at a rate of 1.2%. The chemical composition of the essential oil was determined by gas chromatography-mass spectrometry (GC-MS) analysis. The GC-MS analysis indicated that the principal compounds in the volatile oil of the sample were 4-Pyridinol (28.16%) and thymol (26.58%). The acaricidal activity of E. densa oil against Sarcoptes scabiei (S. scabiei) was tested in vitro. Toxicity test data were analysed using a complementary log-log (CLL) model. The E. densa oil was prepared in five concentrations by dilution with liquid paraffin (1, 2, 4, 8 and 16 mg/ml) and exhibited strong toxicity against S. scabiei with LT&lt;sub&gt;50&lt;/sub&gt; values of 16.637, 5.075, 2.884, 1.184 and 0.760 h, respectively. The LC&lt;sub&gt;50&lt;/sub&gt; values were 7.678, 4.623, 2.543, 1.502, 1.298 and 0.981 mg/ml for S. scabiei at 1, 2, 4, 8, 16 and 24 h, respectively. Compared to the control, the essential oil showed significant effects against S. scabiei in vitro. At 16 mg/ml, E. densa oil was found to kill all mites within a 16-h period. The results indicate that E. densa oil possesses potential acaricidal activity in vitro and may be exploited as a novel drug for the effective control of S. scabiei.

Distribution Characteristics and Implication of n-alkanes in Soils and Plants in Alpine Meadow

The present study was conducted to investigate the n-alkane composition of typical alpine meadows. Plant and soil samples were collected and analyzed to characterize the n-alkane components. The results show that the n-alkane with maximum concentration (Cmax) was C22 in Ligularia virgaurea and Aconitum pendulum, C29 in Elsholtzia densa, Pedicularis kansuensis and Oxytropis kansuensis, and C31 in Potentilla anserine and Leontopodium nanum. Furthermore, the C29 and C31 concentrations in the surface soil from typical alpine meadow were higher than that in sub-layer soil; however, the opposite relationship was seen in soil from degraded alpine meadow. In addition, the correlation between the long chain n-alkanes in soils and plants was strongly significant (p < 0.01, r = 0.816). The change of the C29 and C31 concentration with soil depth could be related to the plant succession of the alpine meadow.

Essential oil composition of leaves and inflorescences of Elsholtzia densa Benth. from western Himalaya

ABSTRACTThe essential oil compositions of leaves and inflorescences of Elsholtzia densa Benth. from western Himalaya were studied and compared using gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. Altogether, forty constituents comprising 83.3–83.7% of essential oil composition were identified. The leaf essential oil of E. densa was characterized by citral (52.2%), geranyl acetate (3.3%) and geraniol (3.1%), whereas the inflorescence essential oil of E. densa was found to be dominated by pinocarvone (51.9%), cis-pinocamphone (5.2%) and citronellyl acetate (3.4%). The essential oil compositions were compared with earlier reports on Elsholtzia spp. from different geographic regions that revealed noteworthy compositional variability.

The effect of Elsholtzia densa methanolic extract modulates inflammation in vitro and in vivo

Inflammatory diseases being one of the back bending global burden are alarming the world. Established anti-inflammatory drugs exert side-effects, demanding for the development of alternative drugs, likely from natural source because of their diverse chemical nature. The anti-inflammatory activity of aerial part methanol extract of Elsholtzia densa collected from the natural forest of Naranag area of Kashmir valley was evaluated both in vitro and in vivo model systems using Macrophages RAW 264.7 cells and acute (carrageenan and histamine-induced rat paw edema) and chronic model (formaldehyde induced arthritis) respectively. The EDM extract exhibited a significant decline in the paw volume being at par with the standard drug Diclofenac (10 mg/kg) as compared with the control group. The reduction was observed in dose dependent manner with 300 mg/kg resulting in 27.27% and 100 mg/kg in 16.88% inhibition at 3rd h. A statistically significant (p < 0.05) decline in the secretion of serum pro-inflammatory cytokines like TNF-α, IL-1 β and IL-6 was found with 80.93%, 75.33% and 67.09%, and 83.25%, 62.11% and 66.69% in EDM-300 as compared with the carrageenan and histamine group respectively. The pro-inflammatory cytokines levels showed clampdown in LPS stimulated RAW264.7 by the extract treatments. The LC–MS data revealed the presence of Quercetin 3-glycosides, Apigenin 7-(2″-acetyl-6″-methylglucuronide) and betulinic acid as major compounds present in EDM extract. Results obtained from in vivo experiments demonstrate that oral administration of EDM extract significantly attenuated inflammation in carrageenan and histamine-induced paw edema, and improved chronic models (formaldehyde induced arthritis).

Hepatoprotective Potential of Elsholtzia densa Against Acute and Chronic Models of Liver Damage in Wistar Rats.

The aim of the present study was to evaluate the hepatoprotective activity of methanolic extract of Elsholtzia densa against experimentally induced acute (CCl4) and chronic (paracetamol) liver injury in albino wistar rats. Activity was measured by monitoring the serum levels of ALT, ALP AST and LDH, total protein levels, bilirubin and albumin. The results of the CCl4 and paracetamol-induced liver toxicity experiments showed that the rats treated with the methanolic extract of Elsholtzia densa exhibited a significant decrease in biochemical parameters as well as the proteins, which were all elevated in the CCl4 and paracetamol group. The extract at a concentration of 300 mg/kg body wt. showed a significant decline (P≤0.05) in the levels of AST, ALT, ALP and LDH to 69.50±2.23IU/L, 60.01±2.25IU/L,46.20±2.24 IU/L and 150.21±5.68IU/L in CCl4 injected animals and 51.12±2.20 IU/L,49.15±3.25 IU/L, 44.12±2.56 IU/L and 125.15±4.45 IU/L in paracetamol-treated animals when compared to the control group. The activities of tissue antioxidants GSH, GPx, GR, GST and CAT was significantly (P≤0.05) restored in dose dependent manner in animals treated with extracts as with acute and chronic hepatotoxic models. The current study confirmed the hepatoprotective effect of methanolic extract of Elsholtzia densa against the model hepatotoxicant CCl4 and paracetamol.

&lt;i&gt;In vitro&lt;/i&gt; antioxidant, antibacterial and anti-tumor activities of total flavonoids from &lt;i&gt;Elsholtzia densa&lt;/i&gt; Benth

Purpose : To investigate the in vitro antioxidant, antibacterial and anti-tumor activities of total flavonoids from Elsholtzia densa Benth of Sichuan Province, China. Methods : The total flavonoids of Elsholtzia densa Bent were extracted utilizing the ultrasonic extraction method, and purified by D101 macroporous adsorption resin. An in vitro antioxidant test, 3-(4,5dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and iCELLigence system were used to evaluate their antioxidant, antibacterial and anti-tumor activities. Results : The results showed that the total flavonoids exhibited good scavenging ability in hydroxyl radical (•OH), DPPH free radical (DPPH•), and super oxide anion radical (O 2 - •). Antioxidant activity was higher than for control (ascorbic acid). Their antibacterial activity was good with minimum inhibitory concentration (MIC) of 2, 4 and 14 μg/mL against Escherichia coli, Staphylococcus aureus and Bacillus subtilis, respectively. Anti-proliferation data from the iCELLigence system studies showed that the total flavonoids significantly inhibited the growth of five types of cells, including a normal human hepatocytes cell line (L02), two human hepatocellular carcinoma cell line (SMMC-7721 and HepG-2), a human cervical cancer cell line (Hela) and a Baby Hamster Syrian Kidney cell line (BHK-21) (p < 0.05). AO/EB staining indicate that the total flavonoids might cause apoptosis of Hela cells. Conclusion : The results suggest that the total flavonoids from Elsholtzia densa Bent are potential natural antioxidants and antimicrobial agent, with anti-cancer properties. Keywords : Elsholtzia densa Benth., Total flavonoids, Antioxidant activity, Antibacterial activity, Antitumor activity

Target-guided isolation and purification of antioxidants from Elsholtzia densa benth. var. densa by DPPH antioxidant assay and dual-mode HSCCC

Elsholtzia densa Benth. var. densa (Lamiaceae) is a famous medicinal herb which has been widely used for treatment of colds, headaches, pharyngitis, fever, diarrhea, digestion disorder, rheumatic arthritis, nephritises, and nyctalopia in China. In this study, fraction of the ethyl alcohol extract of E. densa (aerial part) by different polarity solvents indicated that the ethyl acetate soluble fraction exhibited a potent 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity with the IC50 value of 148.2 μg/mL. Under the target guidance of DPPH experiment, isoquercitrin, trachelogenin, ethyl caffeate, and arctigenin were separated with purities 95.98%, 92.98%, 96.07%, and 88.83%, respectively, by a dual-mode high-speed counter-current chromatography (HSCCC) method using n-hexane–ethyl acetate–methanol–water (4.5:5:3:4, v/v/v/v) as the solvent system. In order to evaluate the scientific basis, antioxidant activity of four isolated compounds was assessed by the radical scavenging effect on DPPH radical; isoquercitrin and ethyl caffeate showed stronger antioxidant activities with IC50 values of 9.4 μg/mL and 9.2 μg/mL, respectively, while trachelogenin and arctigenin showed weak antioxidant activities with IC50 values of &gt;500 μg/mL and 72.8 μg/mL, respectively. Results of the present study indicated that the combinative method using DPPH antioxidant assay and dual-mode HSCCC could be widely applied for rapid screening and isolating of antioxidants from complex traditional Chinese medicine extract.