Chemical Composition and Antimicrobial Activity of Essential Oils from Chromolaena laevigata during Flowering and Fruiting Stages

The chemical compositions and antimicrobial activities of essential oils from the leaves, stems, capitula, and cypselas of Chromolaena laevigata were evaluated at two different phenological stages, flowering and fruiting. Thirty‐eight compounds were identified in the crude oils by GC/MS. The sesquiterpene laevigatin was the major constituent of the leaf, capitulum, and cypsela oils, while the sesquiterpene spathulenol was the main component in the stem oils. The antimicrobial activities of the oils were evaluated against Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Stem oil obtained from Chromolaena laevigata during the fruiting stage generally showed the highest activity with minimum inhibitory concentration (MIC) values of 62.5 μg/ml against Candida albicans and S. aureus, and 500 μg/ml against P. aeruginosa and E. coli. Pure laevigatin exhibited MIC values of 500 and 125 μg/ml against C. albicans and S. aureus, respectively, indicating that this constituent could be responsible, at least in part, for the antimicrobial activities detected in the crude oils. More studies concerning the biological activities of isolated derivatives are required to improve our knowledge of the antimicrobial potential of volatile compounds present in native plants.     

Chemical Composition and Antimicrobial Activity of Essential Oils from Scabiosa arenaria Forssk. Growing Wild in Tunisia

The essential oils isolated from three organs, i.e., fruits, stems and leaves, and flowers, of the endemic North African plant Scabiosa arenaria Forssk . were screened for their chemical composition, as well as their possible antibacterial, anticandidal, and antifungal properties. According to the GC‐FID and GC/MS analyses, 61 (99.26% of the total oil composition), 79 (98.43%), and 51 compounds (99.9%) were identified in the three oils, respectively. While α‐thujone (34.39%), camphor (17.48%), and β‐thujone (15.29%) constituted the major compounds of the fruit oil, chrysanthenone (23.43%), together with camphor (12.98%) and α‐thujone (10.7%), were the main constituents of the stem and leaf oil. In the case of the flower oil, also chrysanthenone (38.52%), camphor (11.75%), and α‐thujone (9.5%) were identified as the major compounds. Furthermore, the isolated oils were tested against 16 Gram‐positive and Gram‐negative bacteria, four Candida species, and nine phytopathogenic fungal strains. It was found that the oils exhibited interesting antibacterial and anticandidal activities, comparable to those of thymol, which was used as positive control, but no activity against the phytopathogenic fungal strains was observed.     

Analysis of Chemical Composition and Assessment of Antioxidant,Cytotoxic and Synergistic Antibacterial Activities of Essential Oils from Different Plant Parts of Piper boehmeriifolium

The essential oils (EOs) from leaves, stems, and whole plant of Piper boehmeriifolium were analyzed using GC/FID and GC/MS. The main constituents of P. boehmeriifolium EOs were β‐caryophyllene, caryophyllene oxide, β‐elemene, spathulenol, germacrene D, β‐selinene, and neointermedeol. The antioxidant potential of the EOs were determined using DPPH^?, ABTS^?+ and FRAP assays. In ABTS^?+ assay, the leaf oil exhibited a remarkable activity with an IC₅₀ value of 7.36 μg/mL almost similar to BHT (4.06 μg/mL). Furthermore, the antibacterial activity of the oils as well as their synergistic potential with conventional antibiotics were evaluated using microdilution and Checkerboard assays. The results revealed that the oils from different parts of P. boehmeriifolium inhibited the growth of all tested bacteria and the minimum inhibitory concentrations were determined to be 0.078 – 1.250 mg/mL. In combination with chloramphenicol or streptomycin, the oils showed significant synergistic antibacterial effects in most cases. Besides, the results of MTT assay indicated that the oil of the whole plant exhibited significant cytotoxic activities on human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF‐7). In summary, the P. boehmeriifolium oils could be regarded as a prospective source for pharmacologically active compounds.     

Essential Oils of Polyalthia suberosa Leaf and Twig and Their Cytotoxic and Antimicrobial Activities

Essential oils from the leaf and twig of Polyalthia suberosa (Roxb.) Thwaites were analyzed using GC/MS/FID. A total of sixty-three constituents were namely identified accounting for 96.03 and 94.12 % in the hydrodistilled oils of the leaf and twig, respectively. Monoterpenes, monoterpenoids, sesquiterpenes, and sesquiterpenoids were characteristic derivatives of P. suberosa essential oils. Sesquiterpenes bicyclogermacrene (26.26 %) and (E)-caryophyllene (7.79 %), and monoterpene β-pinene (12.71 %) were the major constituents of the leaf oil. Sesquiterpenes (E)-caryophyllene (17.17 %) and α-humulene (9.55 %), sesquiterpenoid caryophyllene oxide (9.41 %), and monoterpenes camphene (8.16 %) and tricyclene (6.35 %) were to be main components in the twig oil. The leaf oil indicated cytotoxic activity against three cancer cell lines HepG2, MCF7 and A549 with the IC₅₀ values of 60.96–69.93 μg/mL, while the twig oil inhibited MCF7 with the IC₅₀ value of 66.70 μg/mL. Additionally, the twig oil successfully suppressed the growth of the negative Gram bacterium Pseudomonas aeruginosa, fungus Aspergillus niger, and yeast Candida albicans with the same MIC value of 50 μg/mL, whereas the leaf oil had the same result on the negative Gram bacterium Escherichia coli.     

Antiproliferative effects of essential oils and their major constituents in human renal adenocarcinoma and amelanotic melanoma cells

Abstract. Objectives: The purpose of this study was to evaluate cytotoxic activity of Platycladus orientalis, Prangos asperula and Cupressus sempervirens ssp. pyramidalis essential oils and to identify active components involved in inhibition of population growth of human cancer cell lines. Materials and methods: Essential oils were obtained by hydrodistillation and were analysed by gas chromatography and gas chromatography coupled to mass spectrometry. Antiproliferative activity was tested on amelanotic melanoma C32 cells and on renal cell adenocarcinoma cells, using the sulphorhodamine B assay. Results: Cupressus sempervirens ssp. pyramidalis leaf oil exerted the highest cytotoxic activity with an IC₅₀ value of 104.90 µg/mL against C32, followed by activity of P. orientalis and P. asperula on the renal adenocarcinoma cell line (IC₅₀ of 121.93 and 139.17 µg/mL, respectively). P. orientalis essential oil was also active against amelanotic melanoma with an IC₅₀ of 330.04 µg/mL. Three identified terpenes, linalool, β‐caryophyllene and α‐cedrol, were found to be active on both cell lines tested. Conclusions: Our findings provide novel insights into the field of cytotoxic properties of essential oils. This study provided evidence on how cytotoxic activity of the oils is not always related to their major constituents, except for lower activity found in both cell lines for α‐cedrol. Interestingly, β‐caryophyllene and linalool exhibited comparable IC₅₀ values to the commercial drug vinblastine on the ACHN cell line. This opens a new field of investigation to discover mechanisms responsible for the observed activity.     

Evaluation of in vitro antimicrobial activity of leaf and stem essential oils of <Emphasis Type="Italic">Chloroxylon swietenia</Emphasis> DC.

The essential oils obtained by hydrodistillation of leaves and stems of Chloroxylon swietenia DC. were analysed by GC and GC-MS. The main components in the leaf oil were limonene, pregeijerene, geijerene and germacrene D, while stem oil was rich in limonene, methyl eugenol, pregeijerene and geijerene. The essential oils were evaluated for antimicrobial activity against two gram-positive and two gram-negative bacteria and four pathogenic fungi using agar disc diffusion technique. Subsequently, the minimum inhibitory concentration (MIC) from oils was determined by broth microdilution. Both the oils exhibited moderate to strong activities against all the organisms tested. Bacillus subtilis was most susceptible at 100 μg/ml of leaf and stem oils with inhibition zones of 15.9 and 13.1 mm respectively. Among all the fungi tested, A. niger inhibited effectively with a zone of inhibition of 14.9 and 11.5 mm for leaf and stem oils respectively. The results obtained suggest that the essential oils of the plant possess antimicrobial properties and serve as a biofriendly source of antimicrobial ingredients for the food and pharmaceutical industries.     

Chemical Composition,Antibacterial, Antioxidant and in Vitro Antidiabetic Activities of Essential Oils from Eruca vesicaria

This work describes the study of the chemical composition and bioactivity of the essential oils (EOs) of the different organs (leaves, flowers, stems and roots) from Eruca vesicaria. According to the GC and GC/MS analysis, all the EOs were dominated by erucin (4‐methylthiobutyl isothiocyanate) with a percentage ranging from 17.9 % (leaves) to 98.5 % (roots). The isolated EOs were evaluated for their antioxidant (DPPH, ABTS and β‐carotene/linoleic acid), antibacterial and inhibitory property against α‐amylase and α‐glucosidase. Most EOs exhibited an interesting α‐glucosidase and α‐amylase inhibitory potential. The roots essential oil was found to be the most active with IC₅₀ values of 0.80±0.06 and 0.11±0.01 μg mL^?1, respectively. The essential oil of roots exhibited the highest antioxidant activity (DPPH, PI=92.76±0.01 %; ABTS, PI=78.87±0.19; and β‐carotene, PI=56.1±0.01 %). The isolated oils were also tested for their antibacterial activity against two Gram‐positive and three Gram‐negative bacteria. Moderate results have been noted by comparison with Gentamicin used as positive control.     

Structural Modification of Stilbenoids from Acanthopanax leucorrhizus and Their Cytotoxic Activity

A new cis‐stilbenoid, 1,9‐dihydroxy‐10‐methoxy‐6H‐dibenzo[b,f]oxocin‐6‐one ( 2 ) was isolated from the AcOEt extract of the stem barks of Acanthopanax leucorrhizus, along with three known stilbenoids, 9‐hydroxy‐10‐methoxy‐6H‐dibenzo[b,f]oxocin‐6‐one ( 1 ), 5‐O‐methyl‐(E)‐resveratrol 3‐O‐β‐d ‐glucopyranoside ( 3 ), and (E)‐resveratrol 3‐O‐β‐d ‐xylopyranoside ( 4 ). Two derivatives ( 2a and 2b ) were synthesized by the structural modification of compound 2, which exhibited certain cytotoxic activities against HT‐29 and HeLa cell lines in vitro. All compounds were structurally characterized by comprehensive analysis of their spectroscopic data and comparison with literature information, and evaluated for their cytotoxic activities against three human tumor cell lines (HL‐60, HT‐29, and HeLa) by the standard MTT assay in vitro. The results showed that derivatives 2a and 2b exhibited strong activities than compounds 2 against HT‐29 and HeLa cell lines.     

Chemical Composition and Antimicrobial Activity of the Essential Oils from New Caledonian Citrus macroptera and Citrus hystrix

The essential oils from the leaves of Citrus macroptera and C. hystrix, collected in New Caledonia, have been analyzed by gas chromatography/mass spectrometry (GC/MS) and evaluated for their antimicrobial activity. A total of 35 and 38 constituents were identified, representing 99.1 and 89.0% of the essential oils, respectively. Both essential oils were rich in monoterpenes (96.1 and 87.0%, resp.), with β‐pinene as major component (33.3 and 10.9%, resp.), and poor in limonene (2.4 and 4.7%, resp.). Other main components of C. macroptera oil were α‐pinene (25.3%), p‐cimene (17.6%), (E)‐β‐ocimene (6.7%), and sabinene (4.8%). The essential oil of C. hystrix was characterized by high contents of terpinen‐4‐ol (13.0%), α‐terpineol (7.6%), 1,8‐cineole (6.4%), and citronellol (6.0%). The antimicrobial activity was evaluated against five bacteria and five fungi strains. Both oils were inactive against bacteria. However, the C. macroptera leaf oil exhibited a pronounced activity against Trichophyton mentagrophytes var. interdigitale, with a minimal‐inhibitory concentration (MIC) of 12.5 μg/ml.     

Chemical Composition and Biological Activities of Tunisian Cupressus arizonica Greene Essential Oils

The chemical composition of the essential oils obtained by hydrodistillation of leaves, stems, and female cones of Cupressus arizonica Greene , grown in Tunisia, was studied by GC‐FID and GC/MS analyses. Altogether, 62 compounds were identified, 62 in the leaf oil, 19 in the cone oil, and 24 in the stem oil. The cone and stem oils were mainly composed by monoterpene hydrocarbons (96.6 and 85.2%, resp.). In the leaf oil, the total sesquiterpene fraction constituted 36.1% and that of the monoterpene hydrocarbons 33.8% of the total oil composition. The three oils were evaluated for their in vitro herbicidal activity by determining their influence on the germination and the shoot and root growth of the four weed species Sinapis arvensis L., Lolium rigidum Gaudin , Trifolium campestre Schreb ., and Phalaris canariensis L. At the highest doses tested (0.8 and 1.0 mg/ml), the leaf essential oil inhibited either totally or almost completely the seed germination and the shoot and root growth of S. arvensis and T. campestre. The oils were also tested for their antifungal activity; however, their effects on the fungal growth were statistically not significant.     

Diversity and antimicrobial activity of endophytic fungi isolated from Nyctanthes arbor-tristis, a well-known medicinal plant of India

Endophytic fungi from Nyctanthes arbor-tristis were isolated and evaluated for their antimicrobial activity. A total of 19 endophytic fungi were isolated from 400 segments of healthy leaf and stem tissues of N. arbor-tristis. Eighteen endophytic fungi were obtained from leaf, while only ten from stem. Alternaria alternata had the highest colonization frequency (15.0%) in leaf, whereas Cladosporium cladosporioides ranked first in stem with a colonization frequency of 12%. The diversity and species richness were found higher in leaf tissues than in stem. The similarity indices between leaf and stem were 0.473 for Jaccard’s and 0.642 for the Sorenson index, respectively. Of 16, 12 (75%) endophytic fungal extracts showed antibacterial activity against either one or more pathogenic bacteria. The endophytic Nigrospora oryzae showed maximum inhibition against Shigella sp. and Pseudomonas aeruginosa. The leaf endophytes Colletotrichum dematium and Chaetomium globosum exhibited a broad range of anibacterial activity and were active against Shigella flexnii, Shigella boydii, Salmonella enteritidis, Salmonella paratyphi, and P. aeruginosa. Nine out of 16 (56.25%) endophytic fungi exhibited antifungal activity to one or more fungal pathogens. Colletotrichum dematium inhibited 55.87% of the radial growth of the phytopathogen Curvularia lunata. The antimicrobial activity of these endophytic microorganisms could be exploited in the biotechnological, medicinal, and agricultural industries.     

Chemical Composition and Biological Studies of the Essential Oil from Aerial Parts of Beta vulgaris subsp. maritima (L.) Arcang. Growing in Tunisia

The chemical composition, antioxidant, cytotoxic, anticholinesterase and anti‐tyrosinase activities of the hydrodistilled essential oil of the aerial parts of Beta vulgaris subsp. maritime (L.) Arcang . from Tunisia have been evaluated. The chemical composition of the oil (yield 0.037% [w/w]), determined by GC‐FID and GC/MS is reported for the first time. Twenty five components, accounting for 98.1% of the total oil have been identified. The oil was characterized by a high proportion of oxygenated sesquiterpenes (39.2%), followed by sesquiterpene hydrocarbons (30.3%) and one apocarotenoids (26.3%). The main compounds were γ‐irone (26.3%), α‐cadinol (12.1%), T‐cadinol (10.6%), bicyclogermacrene (10.4%) and δ‐cadinene (6.0%). The isolated oil was tested for its antioxidant activity using the DPPH^·, ABTS^+·, catalase, and paraoxonase assays and also for its cytotoxic, anticholinesterase, and anti‐tyrosinase activities. The essential oil exhibited high antioxidant activity (IC₅₀ = 0.055 ± 0.006 mg/ml) and important result oncatalase (524.447 ± 2.58 Units/mg protein). Furthermore, it exerted a significant cytotoxic effect against A549 cell line, with IC₅₀ = 42.44 ± 1.40 μg/ml. The results indicate that the essential oil of B. vulgaris subsp. maritima (L.) Arcang . aerial parts may be used in future as an alternative to synthetic antioxidant agents, with potential application in the food and pharmaceutical industries.     

Chemical Characteristics,Antimicrobial, and Cytotoxic Activities of the Essential Oil of Egyptian Cinnamomum glanduliferum Bark

The essential oil isolated from the bark of Cinnamomum glanduliferum (Wall ) Meissn grown in Egypt was screened for its composition as well as its biological activity for the first time. The chemical composition was analyzed by GC and GC/MS. The antimicrobial activity of the oil was assessed using agar‐well diffusion method toward representatives for each of Gram‐positive bacteria, Gram‐negative bacteria, and fungi. The cytotoxic activity was checked using three human cancer cell lines. Twenty seven compounds were identified, representing 99.07% of the total detected components. The major constituents were eucalyptol (65.87%), terpinen‐4‐ol (7.57%), α‐terpineol (7.39%). The essential oil possessed strong antimicrobial activities against Escherichia coli, with an activity index of one and minimum inhibitory concentration (MIC) equaling to 0.49 μg/ml. The essential oil possessed good antimicrobial activities against methicillin‐resistant Staphylococcus aureus, Geotrichum candidum, Pseudomonas aeruginosa, Bacillus subtilis, Helicobacter pylori, Aspergillus fumigatus (MIC: 7.81, 1.95, 7.81, 0.98, 31.25, and 32.5 μg/ml, respectively). A considerable activity was reported against S. aureus and Mycobacterium tuberculosis (MIC; 32.5 and 31.25 μg/ml, respectively). The extracted oil was cytotoxic to colon (HCT‐116), liver (HepG2), and breast (MCF‐7) carcinoma cell lines with IC₅₀ of 9.1, 42.4, and 57.3 μg/ml, respectively. These results revealed that Egyptian Cinnamomum glanduliferum bark oil exerts antimicrobial and cytotoxic activities mainly due to eucalyptol and other major compounds.     

Composition,Antifungal and Antiproliferative Activities of the Hydrodistilled Oils from Leaves and Flower Heads of Pterocephalus nestorianus Nábělek

This article reports the first study of the chemical composition, and antifungal and antiproliferative properties of the volatile extracts obtained by hydrodistillation of the flower heads and leaves of the traditional Kurdish medicinal plant Pterocephalus nestorianus Nábělek , collected in the wild. A total of 55 constituents, 43 of the flower heads’ oil (PFO) and 46 of the leaves’ oil (PLO), respectively, were identified by GC/MS, constituting 99.68% and 99.04% of the two oils, respectively. The oils were obtained in 0.15% and 0.10% yields (w/w), respectively, on air‐dried vegetable material. The prevalent constituents of the PFO were α‐terpineol (2.41%), α‐linalool (6.42%), 6,10,14‐trimethylpentadecan‐2‐one (2.59%), myristic acid (24.65%), and lauric acid (50.44%), while the major components of PLO were (E)‐hex‐2‐enal (2.26%), (E)‐hex‐2‐en‐1‐ol (2.04), myristic acid (34.03%), and lauric acid (50.35%). The two oils showed significant inhibitory and fungicidal activities against the medically important fungi Candida albicans, Candida tropicalis, Microsporum canis, and Trichophyton mentagrophytes, with minimum inhibitory concentration ranging from 0.7 to 3.3 mg/ml and minimum fungicidal concentration varying from 1.4 to 6.6 mg/ml. The antiproliferative activity of the two oils was assayed against one normal and six human tumor cell lines. Both oils showed selective cytotoxic activity, with IC₅₀ values ranging from 1.4 to 3.3 μg/ml.     

Chemopreventive and Antioxidant Activity of the Chamazulene‐Rich Essential Oil Obtained from Artemisia arborescens L. Growing on the Isle of La Maddalena,Sardinia, Italy

The essential oils of Artemisia arborescens growing in Sardinia (Italy), collected during three plant growth stages, i.e., from the vegetative stage to post‐blooming time, were characterized. Moreover, the in vitro antiproliferative and antioxidant activities of the oil isolated from aerial parts collected in February were evaluated. The essential oils belonged to the β‐thujone/chamazulene chemotype, notably with the highest amount of chamazulene (ca. 52%) ever detected up to now in the genus Artemisia and, in general, in essential oils. Quantitative variations in the oil composition were observed as the plant passes from the vegetative to the blooming stage. The oil was tested for its potential tumor cell growth‐inhibitory effect on T98G, MDA‐MB 435S, A375, and HCT116 human cell lines, using the MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) assay. The highest activity was observed on A375 and HCT116 cell lines, with IC₅₀ values of 14 μg/ml. Moreover, the in vitro antioxidant and free radical‐scavenging assays revealed the oil to be an effective scavenger of the ABTS radical cation, with an activity comparable to that of Trolox^®. These results support the use of A. arborescens oil for the treatment of inflamed skin conditions. Finally, the composition of the polar fraction of the A. arborescens aerial parts was also examined, and the main component detected was 5‐O‐caffeoylquinic acid, which was identified for the first time in this plant.     

Chemical Constituent,Antimicrobial Activity,and Synergistic Effect of the Stem,Leaf, and Flower Essential Oil of the Artemisia fragrans Willd. from Khoy

Artemisia fragrans is commonly used as a folk medicine as antispasmodic, anti-pyretic, anti-inflammatory, and abortifacient agents. The villagers use its pungent odor to repel rodents, mites, and pests, as well as its essential oil and smoke after burning to treat lung infections after uprooting the plant. Herein, we extracted the essential oils (EOs) of different parts of the plant and analyzed their chemical compositions and antibacterial activities. The chemical analysis led to the identification of 73, 59, and 57 compounds in the EOs of the stem, leaf, and flower, respectively. All of the EOs exhibited antibacterial activities against both G+ and G− bacteria. The EOs of the leaf and flower were more effective against tested bacteria, except B. anthracis and P. aeruginosa, compared to that of the stem. The binary combination of the EOs (stem and flower) or (stem and leaf) showed a synergistic effect. Statistical analysis indicated EOs of leaf and flower are more potent than that of the stem. These findings suggest the application of leaf and flower of the plant, which not only can prevent its uprooting but also ensure better therapeutic function.     

Antimicrobial,antibiofilm and antitumor activities of essential oil of Agastache rugosa from Xinjiang,China

In the study, we evaluated chemical composition and antimicrobial, antibiofilm, and antitumor activities of essential oils from dried leaf essential oil of leaf and flower of Agastache rugosa for the first time. Essential oil of leaf and flower was evaluated with GC and GC–MS methods, and the essential oil of flower revealed the presence of 21 components, whose major compounds were pulegone (34.1%), estragole (29.5%), and p-Menthan-3-one (19.2%). 26 components from essential oil of leaf were identified, the major compounds were p-Menthan-3-one (48.8%) and estragole (20.8%). At the same time, essential oil of leaf, there is a very effective antimicrobial activity with MIC ranging from 9.4 to 42 μg ml⁻¹ and potential antibiofilm, antitumor activities for essential oils of flower and leaf essential oil of leaf. The study highlighted the diversity in two different parts of A. rugosa grown in Xinjiang region and other places, which have different active constituents. Our results showed that this native plant may be a good candidate for further biological and pharmacological investigations.     

Novel cytotoxic chalcones from Litsea rubescens and Litsea pedunculata

Two novel flavonoids with chalcone skeleton, together with seven known flavonoids, were isolated from the stem barks of Litsea rubescens and Litsea pedunculata. The structures of the new compounds were elucidated on the basis of spectral methods including IR, UV, 1D and 2D NMR. The new chalcones were found to contain the rare epoxy or ethylidenedioxy group. This is the first report on the presence of chalcone in the plant genus Litsea. The cytotoxic potential of two new chalcones was evaluated in vitro against three human tumor cell lines. Both new chalcones displayed potent cytotoxic activities against myeloid leukaemia (HL-60) and epidermoid carcinoma (A431) cell lines and more active than cisplatin (DDP). Interestingly, compound 1 exhibited cytotoxic activity against HL-60 with IC₅₀ value 2.1-fold more sensitive to DDP.     

Antimicrobial,Antioxidant, and Anti-Inflammatory Activities of Essential Oils from Five Selected Herbs

Eucalyptus bridgesiana, Cymbopogon martinii, Thymus vulgaris, Lindernia anagallis, and Pelargonium fragrans are five species of herbs used in Asia. Their essential oils were analyzed by GC-MS, and a total of 36 components were detected. The results of our study indicated that, except for the essential oil of P. fragrans, all of the essential oils demonstrated obvious antimicrobial activity against a broad range of microorganisms. The C. martinii essential oil, which is rich in geraniol, was the most effective antimicrobial additive. All of the essential oils demonstrated antioxidant activities on 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, β-carotene/linoleic acid assay, and nitric oxide radical scavenging assay. Furthermore, the T. vulgaris essential oil, which possesses plentiful thymol, exhibited the highest antioxidant activity. For P. acnes-induced secretion of pro-inflammatory cytokines, the essential oils of P. aeruginosa, C. martinii, and T. vulgaris reduced the TNF-α, IL-1β, and IL-8 secretion levels of THP-1 cells.     

Composition, and antimicrobial and remarkable antiprotozoal activities of the essential oil of rhizomes of Aframomum sceptrum K. Schum. (Zingiberaceae)

The essential oil from the rhizomes of Aframomum sceptrum (Zingiberaceae) was analyzed by GC/MS, and its major constituents were found to be β‐pinene (12.7%), caryophyllene oxide (10.0%), and cyperene (6.0%). The oil was also evaluated for antimicrobial activities, in comparison with β‐pinene, caryophyllene oxide, and the leaf essential oil of Melaleuca alternifolia (Myrtaceae). The A. sceptrum essential oil exhibited bacteriostatic activity against the Gram‐positive bacteria Bacillus subtilis, Staphylococcus epidermidis, and S. aureus, but not against Gram‐negative bacteria. Moreover, it showed mild fungicidal activity against Candida albicans and Aspergillus fumigates, and remarkable antiprotozoal activity against Trypanosoma brucei brucei (MLC of 1.51 μl/ml) and Trichomonas vaginalis (IC₅₀ of 0.12±0.02 and MLC of 1.72 μl/ml).