Larvicidal effect of Cedrus libani seed oils on mosquito Culex pipiens

The aim of this research was to determine the larvicidal activity of essential oils obtained from the seeds of six different Cedrus libani A. Rich. (Pinaceae) populations on Culex pipiens L. (Diptera: Culicidae). The essential oil was obtained from seeds by hydrodistillation. Third and fourth instar mortalities from six concentrations (10, 25, 50, 100, 200, and 400?ppm) of oil from each Cedrus population were compared with those of a standard larvicide, temephos. Seed oils from Pozant?, Degirmenlik, Aslankoy, Avlankuzu, Camkuyusu, and Sogutozu populations in Turkey showed high larvicidal activities, with LC₅₀ values of 47.8, 59.0, 66.6, 105.5, 109.3, and 116.0?ppm, respectively. The data showed that there were significant differences among the oils from different C. libani populations in terms of larvicidal activity. Our overall results suggest that essential oil of C. libani has potential to be used in the search for chemical components as new larvicides.     

Chemical composition and mosquito larvicidal activities of Salvia essential oils

Context: Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. In this context, essential oils have received much attention as potentially useful bioactive compounds against insects. Therefore, our present study aimed to evaluate the efficacy of essential oils from the aerial parts of Salvia elegans Vahl, Salvia dorisiana Standl., Salvia splendens Sello ex J.A. Schult Blue Ribbon, and S. splendens Sello ex J.A. Schult Scarlet Sage Red (Lamiaceae) against the fourth instar larvae of Aedes albopictus Skuse (Diptera: Culicidae).

Objective: The mosquito larvicidal activities of the essential oils and chemical composition of four taxa of Salvia are investigated in this article for the first time.

Materials and methods: Chemical compositions of essential oils obtained from four taxa of Salvia were analyzed by gas chromatography-mass spectrometry (GC-MS), GC-FID, and the effects of essential oils on fourth instar larvae of A. albopictus were investigated.

Results: The main components identified from each Salvia essential oils were as follows: spathulenol (38.73%) and caryophyllene (10.32%) from S. elegans; ledol (45.8%) and 4,4'-[(p-phenylene)diisopropylidene]diphenol (17.38%) from S. dorisiana; β-cubebene (22.9%), and caryophyllene (12.99%) from S. splendens Blue Ribbon; phytol (41.46%) and cyclooctasulfur (24.88%) from S. splendens Scarlet Sage Red. The essential oils of S. elegans and S. splendens Blue Ribbon had excellent inhibitory larvicidal effect against A. albopictus larvae, and their LC₅₀ values in 24?h were 46.4?ppm (LC₉₀?=?121.8?ppm) and 59.2?ppm (LC₉₀?=?133.0?ppm), respectively.

Discussion and conclusion: These findings demonstrate that the essential oils of these Salvia species could be considered as the powerful candidates to bring about useful botanicals so as to prevent the resurgence of mosquito vectors.     

Chemical composition and antibacterial activity of essential oils of Lantana camara,Ageratum houstonianum and Eupatorium adenophorum

Essential oils have applications in folk medicine, food preservation, and as feed additives. The essential oils of Lantana camara Linn. (Verbenaceae), Ageratum houstonianum Mill. (Asteraceae) and Eupatorium adenophorum Spreng. (Asteraceae) were analyzed by Gas chromatography-mass spectrometry (GCMS). In L. camara oil, of the total identified (83.91%) volatile constituents, five constituents [3,7,11-trimethyl-1,6,10-dodecatriene (28.86%), β-caryophyllene (12.28%), zingiberene (7.63%), γ-curcumene (7.50%) and α-humulene (3.99%)] represented the major ones. In A. houstonianum oil, among the total identified volatile constituents (94.51%), three [precocene-II (52.64%), precocene-I (22.45%) and β-caryophyllene (9.66%)] represented the major ones. In E. adenophorum oil, of the total identified volatile constituents (84.95%), six [1-napthalenol (17.50%), α-bisabolol (9.53%), bornyl acetate (8.98%), β-bisabolene (6.16%), germacrene-D (5.74%) and α- phellandrene (3.85%)] represented the major ones. The antibacterial activity expressed as Minimum Bactericidal Concentration (MBC) (μg/mL) was determined by the broth dilution method. The essential oil of E. adenophorum had antibacterial activity against Arthrobacter protophormiae, Escherichia coli, Micrococcus luteus, Rhodococcus rhodochrous, and Staphylococcus aureus with MBC values of 200, 100, 100, 12.5, and 200, respectively. The essential oil of A. houstonianum showed antibacterial activity against M. luteus and R. rhodochrous with MBC of 100 and 12.5, but not against A. protophormiae, E. coli, and S. aureus. The essential oil of L. camara showed antibacterial activity against A. protophormiae, M. luteus, R. rhodochrous and S. aureus with MBC of 50, 25, 12.5, and 200, respectively, but not against E. coli. MBC was lowest for R. rhodochrous for all the three essential oils.     

Chemical Composition of Essential Oils from Leaves and Twigs of Pistacia lentiscus,Pistacia lentiscus var. chia,and Pistacia terebinthus from Turkey

The composition of the essential oils from the leaves and twigs of Pistacia lentiscus L., Pistacia lentiscus var. chia (L.), and Pistacia terebinthus L. of Turkish origin were analyzed by gas chromatography/mass spectrometry (GC/MS). Seventy-seven constituents were characterized from the essential oil of P. terebinthus leaves with α-cadinol (6.9%), phytol (5.4%), δ-cadinene (5.1%), α-terpineol (5.0%), and bornyl acetate (4.4%) as major constituents. Germacrene D (10%), β-pinene (7.5%), bornyl acetate (6.0%), α-cubebene (5.9%), and cubebol (5.4%) were found to be the main components among the 61 compounds characterized in the essential oil of P. terebinthus twigs. Forty-six compounds were characterized from the essential oil of P. lentiscus twigs with sabinene (23.2%), α-pinene (19.4%), germacrene D (14.1%), limonene (6.9%), β-phellandrene (6.5%), terpinene-4-ol (5.7%), and β-caryophyllene (5.7%) as the main constituents. Terpinene-4-ol (29.2%), β-caryophyllene (29.2%), and p-cymene (7.1%) were identified as the major components among the 64 compounds characterized in the essential oil of P. lentiscus leaves. Sixty-eight compounds were found on the essential oil of P. lentiscus var. chia leaves with germacrene D (20.1%), myrcene (13.9%), β-caryophyllene (10.8%), and α-terpinyl acetate (4.8%) as the major constituents. Myrcene (27.4%), germacrene D (21.7%), and β-caryophyllene (7.2%) were found to be the main components among 50 compounds characterized in the essential oil of P. lentiscus var. chia twigs.     

Anti-inflammatory activity of essential oil from leaves of Myrciaria tenella and Calycorectes sellowianus

The GC-MS analysis revealed that the leaf essential oils of Myrciaria tenella (DC.) Berg and Calycorectes sellowianus O. Berg (Myrtaceae) were composed of 34 and 37 compounds, respectively. The main constituents of M. tenella oil were β-caryophyllene (25.1%), and spathulenol (9.7%), while for C. sellowianus were guaiol (13.1%) and β-caryophyllene (8.6%). The anti-inflammatory effect of both essential oils was investigated in vitro and in vivo. Both oils reduced significantly (p < 0.005) the treated neutrophils chemotaxis with 93% and 91% inhibition for M. tenella and C. sellowianus, respectively. However, in the systemic treatment with the essential oils (50?mg/kg p.o.) only the M. tenella oil was able to significantly reduce the carrageenan-induced paw edema with a similar effect to that observed for indomethacin (10?mg/kg), the positive control.     

Identification of the main volatile compounds in the leaf and flower of <Emphasis Type="Italic">Tithonia diversifolia</Emphasis> (Hemsl) Gray

The composition of the essential oils of the leaves and flowers of Tithonia diversifolia (Hemsl) A. Gray, Mexican sunflower, are reported. The oils were obtained by hydrodistillation in an all-glass Clevenger-type apparatus and analyzed by GC–MS. The leaf oil was comprised of an abundance of α-pinene (32.9%), β-caryophyllene (20.8%), germacrene D (12.6%), β-pinene (10.9%) and 1, 8-cineole (9.1%). Germacrene D (20.3%), β-caryophyllene (20.1%) and bicyclogermacrene (8.0%) characterized the oil of the flower. A number of aliphatic fatty acids and a diterpenoid compound, sandaracopimaradiene, that were present in the flower, could not be detected in the leaf oil.     

Miscellaneous contributions to the essential oils of plants from various territories. LI. On the components of essential oils of Torilis japonica (Houtt.) DC

The essential oils of Torilis japonica (Houtt.) DC. (Japanese name, Yabujirami) of the family Umbelliferae were prepared from fresh whole herbs and fruits, and investigated by using gas chromatographic and mass spectrometric analyses. The fruits of this plant had been used as a substitute in Japan for a Chinese crude drug Zya-syo-si: Cnidii Monnieri Fructus. Fifty three components were positively identified in the essential oils. The main components of the essential oil were germacrene-D (57.9-71.8% in the oil), alpha-humulene (2.4-13.2%), bicyclogermacrene (1.9-5.4%), beta-caryophyllene (1.5-4.6%), and delta-cadinene (1.0-1.9%).     

Molluscicidal and larvicidal activities and essential oil composition of Cymbopogon winterianus

Abstract

Context. Cymbopogon winterianus Jowitt ex Bor (Poaceae), known as citronella grass, is an aromatic herbaceous plant and the essential oil extracted from this grass is used in cosmetics, perfumes, hygiene and cleanliness products worldwide.

Objective: This study investigated the composition and molluscicidal and larvicidal activities of the essential oil of C. winterianus cultivated in North Brazil.

Materials and methods: The oil was obtained by hydrodistillation, analyzed by gas chromatography (GC) and GC-mass spectrometry and then its molluscicidal and larvicidal activities against snails (Biomphalaria glabrata) and hatched larvae of Artemia salina, respectively, were evaluated at concentrations from 10 to 1000?mg/L.

Results: The main constituents of oil were citronellal (26.5%), geraniol (16.2%), elemol (14.5%) and citronellol (7.3%). The molluscicidal test revealed significant lethal concentration (LC) values (LC₉₀?=?97.0?mg/L, LC₅₀?=?54.0?mg/L and LC₂₀?=?22.0?mg/L), indicating the presence of molluscicidal compounds in the oil. In addition, the oil showed moderate larvicidal activity (LC₅₀?=?181.0?mg/L) against the larvae of A. salina, which could justify its use in the aquatic environment without affecting other living organisms.

Discussion and conclusion: The results suggest that the oil of C. winterianus could be an effective alternative to control schistosomiasis, with an average margin of safety to other living organisms that coexist with snails.     

Chemical composition,antimicrobial, and cytotoxicity studies on S. erianthum and S. macranthum essential oils

Context: Solanum erianthum D. Don and Solanum macranthum Dunal (Solanaceae) are widely used in traditional medicine. The leaves act as an abortifacient and in particular to treat leucorrhoea, sores, and skin irritations.

Objective: This study was undertaken to characterize the volatile constituents of the leaf and fruit essential oils of S. erianthum and S. macranthum; their antimicrobial and in vitro cytotoxic bioassay against human breast and prostate tumor cells.

Methods: The volatile oils were obtained by hydrodistillation and analyzed for their constituents by gas chromatography-mass spectrometry (GC-MS). Minimum Inhibitory Concentrations (MIC) were determined using the microbroth dilution technique while the cytotoxic potentials were evaluated using the Cell Titre 96^(R) AQ_ueous Non-Radioactive Cell Proliferation Assay method.

Results: Solanum erianthum essential oils were characterized by the abundance of α-terpinolene (17.8%), α-phellandrene (17.5%), p-cymene (15.7%) and β-pinene (11.7%) in the leaves; α-humulene (23.1%), humulene epoxide II (20.0%), caryophyllene oxide (16.5%), methyl salicylate (11.8%) and β-caryophyllene (10.9%) in the fruits. The leaf oil of S. macranthum consisted of (E)-phytol (29.0%), pentadecanal (28.1%) and pentadecane (7.7%) while the major fruit oil constituents were α-humulene (36.5%), β-caryophyllene (17.8%), ethyl palmitate (9.4%), and methyl salicylate (8.2%). Solanum erianthum leaf volatile oil demonstrated potent inhibitory activity against Hs 578T and PC-3 human breast and prostate tumor cells respectively. In addition, the Solanum essential oils exhibited significant antimicrobial activity (19.5–625 µg/mL) on pathogens employed in the assay.

Conclusion: The Solanum essential oils possess strong antimicrobial activity in addition to the potent cytotoxic potential of S. erianthum leaf oil against Hs 578T and PC-3 cells.     

Chemical composition and bioactivity of essential oils of Hypericum helianthemoides. Hypericum perforatum and Hypericum scabrum

Context: A number Hypericum species are well known for their therapeutic efficacy and use in traditional medicine. The various species of Hypericum have been traditionally used for the treatment of wounds, eczema, burns, trauma, rheumatism, neuralgia, gastroenteritis, ulcers, hysteria, bedwetting and depression.

Objective: This study evaluated the in vitro antioxidant, antibacterial and phytochemical properties of essential oils of Hypericum helianthemoides (Spach) Boiss., Hypericum perforatum L. and Hypericum scabrum L. (Hypericaceae) collected from alpine region of Southwest Iran.

Materials and methods: The essential oils obtained from dried flowering aerial parts of three Hypericum species were analyzed by gas chromatography and gas chromatography/mass spectrometry to determine chemical compositions. The antibacterial activity of essential oils within concentration ranges from 16 to 500?µg/mL was individually evaluated against Bacillus cereus, Listeria monocytogenes. Proteus vulgaris and Salmonella typhimurium. The 1,1-diphenyl-2-picrilhydrazyl (DPPH) radical scavenging activity of essential oils was determined using DPPH assay.

Results: Essential oil yield of H. helianthemoides. H. scabrum and H. perforatum were 0.12, 0.20 and 0.21?mL/100?g dried material, respectively. The major constituents of the essential oils were α-pinene (12.52–49.96%), β-pinene (6.34–9.70%), (E)-β-ocimene (4.44–12.54%), β-caryophyllene (1.19–5.67%), and germacrene-D (2.34–6.92%). The essential oils of three Hypericum species indicated moderate-to-good inhibitory activities against four bacteria, especially against L. monocytogenes.

Discussion and conclusion: The essential oils of the three studied Hypericum species sourced in alpine region of West Iran were rich in monoterpene and sesquiterpenes hydrocarbons. Among the three tested species, the essential oil of H. scabrum showed the highest antibacterial and antioxidant activities.     

Synergistic terpene combinations as larvicides against the dengue vector Aedes aegypti Linn.

Most of the essential oils (EO) known for mosquitocidal activity contain terpenes as part of their chemical constituents. In this study, four monoterpenes namely γ-terpinene (T), R-(+)-limonene (L), carvacrol (C), and trans-anethole (A) were screened against late third instar Aedes aegypti Linn. larvae singly and in combination to find out the synergistic interaction. The monoterpenes γ-terpinene, R-(+)-limonene, trans-anethole, and carvacrol showed larvicidal activity with LC₅₀ values of 9.76, 11.88, 50.19, 48.57 ppm and LC₉₀ values of 16.99, 17.78, 65.21, 75.02 ppm, respectively for Ae. aegypti when tested individually. Prepared binary combinations at LC₂₀ values and studied the synergistic interactions based on cotoxicity factor (CTF) and found that all the binary combinations showed synergistic interactions (CTF > 20). Further, the binary (1:1), ternary (1:1:1), and quaternary (1:1:1:1) terpene combinations on equal weight basis were prepared, evaluated against Ae. aegypti larvae and synergistic interactions were studied by Wadley's method. Among the eight combinations two combinations viz. LC (LC₅₀10.42 ppm) and LA (LC₅₀11.86 ppm) were showing synergistic interactions (R > 1.5) and others were exhibiting additive effect (1.5 ≥ R > 0.5) and none of the combinations showed antagonism (R < 0.5). Among the two methods used the Wadley's method found suitable when combinations were made on an equal weight basis. The two binary combinations found in this study are promising synergistic mixtures which has scope in designing mosquito larvicidal EOs by enriching the EOs with terpenes or by producing EO combinations with these terpenes as chemical constituents in the correct proportions.     

Chemical composition and cytotoxic activity of the leaf essential oil of <Emphasis Type="Italic">Eugenia zuchowskiae</Emphasis> from Monteverde,Costa Rica

The leaf essential oil of Eugenia zuchowskiae from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC–MS. The principal constituents of E. zuchowskiae leaf oil were α-pinene (28.3%), β-caryophyllene (13.2%), α-humulene (13.1%), and α-copaene (8.1%). The leaf essential oil of E. zuchowskiae showed pronounced in-vitro cytotoxic activity against MCF-7, MDA-MB-468, and UACC-257 human tumor cell lines. The major components showed cytotoxic activities comparable to doxorubicin (LC₅₀ 14–70 μg/ml).     

Insecticidal Activities of the Leaf Oils of Eight Cinnamomum. species Against Aedes aegypti. and Aedes albopictus.

Abstract

The leaf oils of eight Cinnamomum. species (C. rhyncophyllum. Miq., C. microphyllum. Ridl., C. pubescens. Kochummen, C. mollissimum. Hook. f., C. impressicostatum. Kosterm, C. scortechinii. Gamb., C. sintoc. Bl., and C. cordatum. Kosterm) were investigated for their larvicidal and adulticidal activities against Aedes aegypti. (Aedes aegypti Lynn) and Aedes albopictus. (Aedes albopictus Skuse). Acute mortalities of the fourth instar larvae and the adult mosquitoes were determined according to the standard WHO methods. Among the essential oils studied, the leaf oils of C. rhyncophyllum., C. microphyllum., C. pubescens., C. mollissimum., and C. impressicostatum. showed significant effects against the larvae of Ae. aegypti. and Ae. albopictus. with concentrations that caused 50% mortality (LC₅₀) values of less than 12.8 and 11.8 µg ml^?1, respectively. The essential oils that showed strong larvicidal effects also demonstrated relatively strong adulticidal effects on the mosquitoes after 3 h exposure with LC₅₀ values ranging from 133.0 to 243.0 µg ml^?1 against Ae. aegypti. and from 118.0 to 194.0 µg ml^?1 against Ae. albopictus.. The efficacy of the oils toward the larvae and adult mosquitoes of both species was nonselective as the LC₅₀ values showed little variation. The chemical composition of the oils was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). This study suggested that the essential oils containing high levels of benzyl benzoate and benzyl salicylate exhibited strong insecticidal activities against the larvae and adult mosquitoes.     

Chemical composition and larvicidal activity of essential oils from Peganum harmala,Nepeta cataria and Phellodendron amurense against Aedes aegypti (Diptera: Culicidae)

Essential oils from aerial parts of the herbs Peganum harmala and Nepeta cataria, and leaves of the tree Phellodendron amurense were analyzed by GC-FID and GC-MS, and their larvicidal activities were assayed on the early fourth instar larvae of Aedes aegypti. The major constituents of the oils were limonene (14.5%) and thymol (11.5%) in P. harmala, thymol (46.5%), 4aα,7α,7aβ-nepetalactone (18.3%) and 4aα,7β,7aα-neptalactone (19.7%) in N. cataria, eugenol (14.5%) andγ-eudesmol (9.5%) in P. amurense.The oil of N. cataria had a strong larvicidal activity (LC₅₀ < 50 µg/mL; LC₉₀ < 86.8 µg/mL) on A. aegypti while the remaining oils showed a moderated killing effect. The larvicidal activity of N. cataria oil was associated to the contents of 1,8-cineol, camphor, 4aα,7α,7aβ-Nepetalactone, 4aα,7β,7aα-Nepetalactone and thymol. Our results indicate that the oil of N. catariadeserves to be used as a source of larvicidal agents against A. aegypti.     

Chemical composition and antibacterial activity of essential oils of <Emphasis Type="Italic">Eugenia</Emphasis> species

The essential oils of the leaves of Eugenia brasiliensis, Eugenia beaurepaireana, and Eugenia umbelliflora were analyzed by GC–MS. The major compounds found in the oil of E. brasiliensis were spathulenol (12.6%) and τ-cadinol (8.7%), of E. beaurepaireana were β-caryophyllene (8.0%) and bicyclogermacrene (7.2%), and of E. umbelliflora were viridiflorol (17.7%) and β-pinene (13.2%). These oils were assayed to determine their antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. All of the oils analyzed showed antibacterial activity, ranging from moderate to strong, which was most accentuated for the E. umbelliflora and E. brasiliensis oils, which strongly inhibited the growth of S. aureus giving values of MIC = 119.2 and 156.2 μg/mL, respectively.     

Chemical Composition and Antibacterial Activity of the Essential Oil of Centella asiatica. Growing in South Africa

ABSTRACT

In South Africa, Centella asiatica. (L.) Urb is used traditionally for the treatment of various diseases. Analyses of the essential oil of this medicinal plant revealed 11 monoterpenoid hydrocarbons (20.20%), nine oxygenated monoterpenoids (5.46%), 14 sesquiterpenoid hydrocarbons (68.80%), five oxygenated sesquiterpenoids (3.90%), and one sulfide sesquiterpenoid (0.76%). α.-Humulene (21.06%), β.-caryophyllene (19.08%), bicyclogermacrene (11.22%), germacrene B (6.29%), and myrcene (6.55%) were the predominant constitutes. The essential oil extract exhibited a broad spectrum of antibacterial activities against Gram-positive (Bacillus subtilis, Staphylococcus aureus.) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Shigella sonnei.) organisms.     

Chemical composition and in vitro cytotoxic effects of the essential oil from Nectandra leucantha leaves

Abstract

Context: Nectandra (Lauraceae) species have been used in folk medicine as an antidiarrheal, analgesic, antifungal, etc., and have many pharmacological proprieties.

Objective: Investigation of the chemical composition and cytotoxicity of essential oil from Nectandra leucantha Nees & Mart. leaves. This is the first study involving N. leucantha reported in the literature.

Material and methods: The essential oil of N. leucantha leaves was obtained by hydrodistillation. Its chemical composition was determined using a combination of GC/FID, GC/MS, and determination of Kovats index (KI). In vitro cytotoxic activity was evaluated against six cancer cell lines – murine melanoma (B16F10-Nex2), human glioblastome (U-87), human cervical carcinoma (HeLa), human colon carcinoma (HCT), human breast adenocarcinoma (MCF7), and human cervical tumor (Siha) as well as against one non-tumorigenic cell line – human foreskin fibroblast (HFF).

Results: Thirty-three compounds were identified primarily sesquiterpenes (81.41%), the main compounds being bicyclogermacrene (28.44%), germacrene A (7.34%), spathulenol (5.82%), and globulol (5.25%). Furthermore, monoterpenes were also found in the analyzed oil (12.84%), predominantly α- and β-pinenes (6.59 and 4.57%, respectively). The crude essential oil displayed significant cytotoxic activity against B16F10-Nex2 (IC₅₀ 33?±?1?μg/mL) and U87 (IC₅₀ 75.95?±?0.03?μg/mL) and HeLa (IC₅₀ 60?±?12?μg/mL) cell lines. The main identified compound, bicyclogermacrene, displayed IC₅₀ ranging from 3.1?±?0.2 to 21?±?6?μg/mL.

Discussion and conclusion: The results indicate that the crude oils from leaves of N. leucantha displayed cytotoxic activity being bicyclogermacrene, the main compound identified in the crude oil responsible, at least in part, for this potential.     

Chemical analysis and in vitro antiviral and antifungal activities of essential oils from Glechon spathulata and Glechon marifolia

Abstract

Context: Glechon spathulata Benth. and Glechon marifolia Benth. (Lamiaceae, Mentheae) are aromatic plants used in traditional medicine for the treatment of viral infections.

Objective: The chemical composition and antiviral and antifungal activities of Glechon spathulata and Glechon marifolia essential oils were investigated.

Materials and methods: The oils were obtained by hydrodistillation and analyzed by GC–FID and GC–MS. Anti-herpes virus (HSV-1) activity was examined in Vero cells by yield reduction assay, in doses of 0.0095% v/v and 0.039% v/v, for G. spathulata and G. marifolia oil, respectively. Antifungal activity was carried by the broth microdilution method, in oil concentrations that ranged from 5.2 to 500?µg/mL.

Results: β-Caryophyllene (14.2% and 32.2% for G. spathulata and G. marifolia, respectively) and bicyclogermacrene (17.1% and 16.5%, respectively) were the major components of both oils. At noncytotoxic concentrations of the essential oils, the viral titer was reduced by up to 2 log₁₀ for KOS and VR-733 strains. The antifungal activity was observed against Trichophyton rubrum (MIC 10–83?µg/mL) and Epidermophyton floccosum (MIC 83–500?µg/mL). The oil of G. spathulata exhibited activity against the three strains tested (KOS, VR733, and 29-R), whereas G. marifolia oil was active against two strains, KOS and VR733.

Discussion and conclusion: The chemical composition for G. spathulata and G. marifolia essential oils is very similar. The oil of G. spathulata can be promising as a new antifungal agent against dermatophytes. The findings add important information to the biological activity of Glechon species essential oils, specifically its antiviral and antidermatophytic properties.     

Effects of β-caryophyllene and Murraya paniculata essential oil in the murine hepatoma cells and in the bacteria and fungi 24-h time–kill curve studies

Context: Orange Jessamine [Murraya paniculata L. (Rutaceae)] has been used worldwide in folk medicine as an anti-inflammatory, antibiotic and analgesic.

Objective: The objective of this study is to investigate the in vitro antioxidant, cytotoxic, antibacterial and antifungal activity and the time-kill curve studies of orange jessamine essential oil and β-caryophyllene, as well as the chemical composition of the essential oil.

Material and methods: The cytotoxic activity of M. paniculata and β-caryophyllene (7.8–500?μg/mL) was evaluated using the MTT assay on normal fibroblasts and hepatoma cells. The minimal inhibitory concentration and time–kill curves (24?h) were evaluated against those of Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Enterococcus faecallis, Aspergillus (niger, fumigates and parasiticum) and F. solani by the broth microdilution method. The antioxidant activity was measured by the DPPH and ABTS assays. Chemical composition was evaluated by GC/MS analyses.

Results: GC/MS analyses identified 13 compounds, with β-caryophyllene as the major compound. The oil exhibited moderate antibacterial activity (MIC <1.0?mg/mL) and strong antifungal activity. Time–kill curve studies showed that either the essential oil or β-caryophyllene presented rapid bacterial killing (4?h for S. aureus) and fungicidal effect (2-4?h for F. solani); however, both displayed weak free radical scavenger capacity. The cytotoxic activity exhibited a prominent selective effect against hepatoma cancer cells (IC₅₀ value =63.7?μg/mL) compared with normal fibroblasts (IC₅₀ value =195.0?μg/mL), whereas the β-caryophyllene showed low cytotoxicity.

Discussion and conclusion: The experimental data suggest that the activities of M. paniculata essential oil are due to the synergistic action among its components.     

Chemical composition and antibacterial activity of essential oils of Tripleurospermum disciforme in three developmental stages

Context: Tripleurospermum disciforme (C.A. Mey) Schultz Bip. (Asteraceae) is a widespread biennial species which also has traditional medicinal uses. According to the few recent studies, essential oils of this species exhibit anti-inflammatory, antispasmodic, antiseptic, antifungal, antiulcer, and antioxidant activity.

Objective: The chemical compositions of the hydrodistilled oils of T. disciforme of Iranian origin are studied in the stages of prior to flowering, flowering, and post flowering, for the first time. Also, we investigated the antibacterial activities of the oils.

Materials and methods: The essential oils of air-dried T. disciforme were obtained by hydrodistillation in three different developmental stages and analyzed by gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the isolated essential oil, in the three stages, was also investigated against four Gram-positive and four Gram-negative bacteria.

Results: Twenty-one components were identified in the essential oils of T. disciforme, and the highest amount of oil was extracted at the flowering stage. The main component of the species in the flowering stage was β-farnesene (22.46%) and the other major components were β-sesquiphellandrene (17.85%), p-methoxy-β-cyclopropylstyrene (16.64%), heptadecane (10.6%), p-methoxy-humulene oxide (6.88%) and benzene acetaldehyde (9.3%). The MIC of essential oil was evaluated from 4 µL ml^?1 against Staphylococcus subtilis and Bacillus cereus to 22 µL ml^?1 against Citrobacter amalonaticus.

Discussion and conclusion: This study demonstrates the occurrence of β-farnesene/β-sesquiphellandrene chemotype of T. disciforme in western regions of Iran that are different from previous reports. The findings also showed that the essential oils T. disciforme have excellent antibacterial activities and thus have great potentiality to be used as a resource for natural health products.