Chemical composition and antimicrobial activity of the essential oils of four Ocimum species growing in Tanzania

Antimetastatic and anti-inflammatory potentials of essential oil from edible Ocimum sanctum leaves

Antimetastatic and anti-inflammatory activities of Ocimum sanctum essential oil (OSEO) have been assessed in this study. OSEO at the concentration of 250 μg/mL and above showed a significant (^*P < 0.05) decrease in the number of migrated cancer cells. In addition, OSEO at concentration of 250 μg/mL and above suppressed MMP-9 activity in lipopolysaccharide (LPS) induced inflammatory cells. A dose-dependent downregulation of MMP-9 expression was observed with the treatment of OSEO compared to the control. Our findings indicate that OSEO has both antimetastatic and anti-inflammatory potentials, advocating further investigation for clinical applications in the treatment of inflammation associated cancer.

Compositional Variability and Antifungal Potentials of Ocimum basilicum, O. tenuiflorum, O. gratissimum and O. kilimandscharicum Essential Oils against Rhizoctonia solani and Choanephora cucurbitarum

The composition of hydrodistilled essential oils of Ocimum basilicum L. (four chemovariants), O. tenuiflorum L., O. gratissimum L., and O. kilimandscharicum Guerke were analyzed and compared by using capillary gas chromatography (GC/FID) and GC-mass spectrometry (GC/MS). Phenyl propanoids (upto 87.0%) and monoterpenoids (upto 83.3%) were prevalent constituents distributed in the studied Ocimum taxa. The major constituents of the four distinct chemovariants of O. basilicum were methyl chavicol (86.3%), methyl chavicol (61.5%)/linalool (28.6%), citral (65.9%); and linalool (36.1%)/citral (28.8%). Eugenol (66.5% and 78.0%) was the major constituent of O. tenuiflorum and O. gratissimum. Eugenol (34.0%), β-bisabolene (15.4%), ( E)-α-bisabolene (10.9%), methyl chavicol (10.2%) and 1,8-cineole (8.2%) were the major constituents of O. kilimandscharicum. In order to explore the potential for industrial use, the extracted essential oils were assessed for their antifungal potential through poison food technique against two phytopathogens, Rhizoctonia solani and Choanephora cucurbitarum, which cause root and wet rot diseases in various crops. O. tenuiflorum, O. gratissimum, and O. kilimandscharicum exhibited complete growth inhibition against R. solani and C. cucurbitarum after 24 and 48 h of treatment. O. basilicum chemotypes showed variable levels of growth inhibition (63.0%–100%) against these two phytopathogens.

Essential oil from Artemisia phaeolepis: chemical composition and antimicrobial activities

Artemisia phaeolepis, a perennial herb with a strong volatile odor, grows on the grasslands of Mediterranean region. Essential oil obtained from Artemisia phaeolepis was analyzed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. A total of 79 components representing 98.19% of the total oil were identified, and the main compounds in the oil were found to be eucalyptol (11.30%), camphor (8.21%), terpine-4-ol (7.32%), germacrene D (6.39), caryophyllene oxide (6.34%), and caryophyllene (5.37%). The essential oil showed definite inhibitory activity against 10 strains of test microorganisms. Eucalyptol, camphor, terpine-4-ol, caryophyllene, germacrene D and caryophyllene oxide were also examined as the major components of the oil. Camphor showed the strongest antimicrobial activity; terpine-4-ol, eucalyptol, caryophyllene and germacrene D were moderately active and caryophyllene oxide was weakly active. The study revealed that the antimicrobial properties of the essential oil can be attributed to the synergistic effects of its diverse major and minor components.

Antimicrobial activity of traditional medicinal plants from Ankober District, North Shewa Zone, Amhara Region, Ethiopia

CONTEXT

Traditional medicinal plants have long been used in Ethiopia to treat human and livestock ailments. Despite a well-documented rich tradition of medicinal plant use in the country, their direct antimicrobial effects are still poorly known.

OBJECTIVE

To investigate the antimicrobial activity of 19 medicinal plant species that were selected based on the ethnobotanical information on their traditional use to treat infectious diseases in Ankober District.

METHODS

About 23 different ethanol extracts of plants obtained by maceration of various parts of 19 medicinal plant species were studied for potential antimicrobial activity using a broth microdilution method against Bacillus cereus, Bacteroides fragilis, Candida albicans, Clostridium perfringens, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes.

RESULTS

Plant extracts from Embelia schimperi Vatke (Myrsinaceae) showed the strongest antibacterial activity with a minimum inhibitory concentration (MIC) value of 64 µg/ml against B. cereus, L. monocytogenes, and S. pyogenes. Growth inhibitory activities were also observed for extracts of Ocimum lamiifolium Hochst. (Lamiaceae) against S. pyogenes, and those of Rubus steudneri Schweinf. (Rosaceae) against S. epidermidis at an MIC value of 128 µg/ml. Generally, 74% of ethanol extracts (17 extracts) showed antimicrobial activity against one or more of the microbial strains tested at an MIC value of 512 µg/ml or below.

DISCUSSION AND CONCLUSIONS

Results confirm the antimicrobial role of traditional medicinal plants of Ankober and warrant further investigations on promising medicinal plant species so as to isolate and characterise chemicals responsible for the observed strong antimicrobial activities.

Enhanced bactericidal effect of enterocin A in combination with thyme essential oils against L. monocytogenes and E. coli O157:H7

The combined effects of enterocin A with Thymus vulgaris essential oils (EOs) against Listeria monocytogenes and Escherichia coli O157:H7 were investigated in vitro by enumeration of surviving populations of testing pathogens and minimal inhibitory concentration (MIC) determination. Enterocin A was purified to homogeneity by RP-HPLC from the culture fluid of Enterococcus strain and thyme EOs were extracted from local Thymus vulgaris plants. The major constituent of thyme EOs oils determined by GC-MS was thymol (78.4 %). Combination of enterocin A with thyme EOs showed an enhanced bactericidal effect against Listeria monocytogenes. Checkerboard assay and isobologram construction displayed a synergistic interaction between these compounds against Listeria (FIC index <0.5). Moreover, the MIC value of enterocin A has fallen fivefold (from 4.57 to 0.9 μg/ml), while the MIC of thyme EOs decreased threefold (from 3.6 to 1.2 μg/ml). Treatments with enterocin A alone did not affect the growth of the enteric pathogen E. coli O157:H7. However, the addition of thyme EOs and enterocin A yielded a synergistic antimicrobial effect against E. coli (MIC thyme EOs decrease from 2.2 to 0.71 μg/ml). This is the first report on the combined effect of enterocin A and thyme EOs against food pathogen bacteria. This combination could be useful in food bio-preservation.

The composition and antibacterial activity of essential oils in three Ocimum species growing in Romania

In this study the glandular hair morphology, chemical composition and antimicrobial activity of the essential oils from three Ocimum species have been investigated (Ocimum basilicum L. var. Genovese, O. gratissimum and O. tenuiflorum). The indumentum shows little variation among the investigated species with both glandular and non-glandular hairs presents. Glandular hairs on the three species are peltate and capitate (with various cell numbers in the stalk and gland). The samples of essential oils obtained from the plant aerial organs by hydrodistillation have been analyzed by GC-MS. Linalool (65.38%, 74.22%, 38.60%), eugenol (5.26%, 3.47%, 10.20%) and tau-cadinol (8.18%, 3.47%, 10.20%) appear as the main components in Ocimum basilicum L. var. Genovese, O. gratissimum and O. tenuiflorum. The oils also contain lower levels of α-bergamotene, 1,8-cineole, germacrene D, β-ocimene, α-caryophyllene, camphor, and α-guaiene. All essential oils showed antibacterial activity against Staphylococcus aureus and Escherichia coli depending on their concentration. Ocimum basilicum L. var. Genovese oil produced the strongest antibacterial effect on S. aureus and E. coli.

Toxicity of essential oil of Satureja khuzistanica: in vitro cytotoxicity and anti-microbial activity

In nature, essential oils play an important role in the protection of the plants by exerting anti-bacterial, -viral, -fungal, -oxidative, -genotoxic, and free radical scavenging properties, as well as in some cases acting as insecticides. Several Satureja species are used in traditional medicine due to recognized therapeutic properties, namely anti-microbial and cytotoxic activities. The purpose of the present work was to determine the biologic activity of the essential oil of S. khuzistanica Jamzad (Lamiaceae) against four human cancer cell lines, as well as its inhibitory effects against a wide array (i.e. n = 11) of pathogenic bacteria and fungi. The essential oil was isolated by hydro-distillation and analyzed by GC-FID and GC-MS. Carvacrol (92.87%) and limonene (1.2%) were found to be the main components of the isolated oil. Anti-microbial activity of the essential oil was assessed using a disc diffusion method; an MTT cytotoxicity assay was employed to test effects of the oil on each cancer cell line. The oil exhibited considerable anti-microbial activity against the majority of the tested bacteria and fungi. The test oil also significantly reduced cell viability of Vero, SW480, MCF7, and JET 3 cells in a dose-dependent manner, with the IC50 values calculated for each cell type being, respectively, 31.2, 62.5, 125, and 125 μg/ml. Based on the findings, it is concluded that the essential oil of S. khuzistanica and its major constituents have a potential for further use in anti-bacterial and anti-cancer applications, pending far more extensive testing of toxicities in normal (i.e. primary) cells.

In vitro Cytotoxic and Antimicrobial Activity of Essential Oil From Satureja Intermedia

BACKGROUND

Many members of the genus Satureja have aromatic and medicinal characteristics. Objectives.

OBJECTIVES

The purpose of the present work was to determine cytotoxic activity of the essential oil of S. intermedia CA Mey (Lamiaceae) on two human cancerous cell lines and its in vitro inhibitory effects against 11 pathogenic bacteria and fungi as well.

MATERIALS AND METHODS

The essential oil was isolated by hydrodistillation and analyzed by combination of capillary GC-FID and GC-MS. The in vitro toxicological study was based on the MTT cytotoxicity assay and antimicrobial activity of the essential oil was studied according to the disc diffusion method and MIC value.

RESULTS

Thymol (34.5%), γ-terpinene (18.2%) and ρ-cymene (10.5%) were the main components of the essential oil. The toxicological study on 5637 and KYSE cell lines showed IC50 values of 156 μg/ml. The essential oil exhibited considerable antimicrobial activity on tested bacteria and fungi.

CONCLUSIONS

From the results of the present study, it may be concluded that the essential oil of S. intermedia and its major constitutes are interesting in antibacterial and anticancer applications.

In vivo anti-inflammatory activities of Ocimum suave in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Ocimum suave has been used in the Ethiopian traditional medicine to relieve pain, fever, inflammation and other disease conditions.

AIM OF THE STUDY

The aim of the present study was to investigate the anti-inflammatory activities of the aqueous and ethanol leaf extracts and some fractions of Ocimum suave in mice.

MATERIALS AND METHODS

The crude extracts were screened for their anti-inflammatory activities on carrageenan-induced mouse paw edema at three dose levels. The butanol and aqueous fractions of the aqueous extract were also evaluated for their anti-inflammatory activities using carrageenan, histamine and serotonin-induced mouse paw edema at three dose levels. Normal saline and aspirin were employed as negative and positive control groups, respectively.

RESULTS

Both ethanol and aqueous extracts significantly decreased carrageenan-induced inflammation at all the three doses used. However, greater paw edema inhibition was observed with the aqueous extract. The two fractions also showed significant reduction of inflammation against inflammatory models in which the aqueous residue exhibited the highest inhibition.

CONCLUSIONS

From the present findings, it can be concluded that the ethanol and aqueous leaf extracts as well as butanol and aqueous fractions of Ocimum suave have shown anti-inflammatory properties.

Chemical and Biological Diversity in Fourteen Selections of Four Ocimum Species

Biomass, essential oil yield, essential oil composition diversity, and antibacterial and antifungal activities of 14 selections of 4 Ocimum species [ Ocimum basilicum L. (selections: T1-T10), O. gratissimum L. (selections: T11-T12), O. tenuflorum L.f., syn. O. sanctum L. (selection: T13) and O. kilimandscharicum Baker ex. Guerke (selection: T14)] were investigated. O. basilicum selections T9 (methyl chavicol: 87.0%) and T10 {( Z)- and ( E)-methyl cinnamate: 69.1%} produced higher biomass (67.8 and 56.7 t/ha) and oil (203.4 and 141.7 kg/ha) yields relative to 8 (T1-T8) linalool (up to 58.9%), or methyl chavicol (up to 61.8%) rich selections. O. gratissimum selection T12 (eugenol: 84.1%, 254.6 kg/ha oil yield) was significantly superior to T11 (62.1% eugenol and 18.4% camphor). O. tenuiflorum (T13, methyl eugenol: 72.5%) and O. kilimandscharicum (T14, camphor: 51.7%) produced 171.7 and 96.2 kg/ha essential oil, respectively. The essential oils exhibited broad spectrum antibacterial (against 5 Gram-positive and 7 Gram-negative bacteria) and antifungal (against 10 fungi) activities. The bacterial species Bacillus subtilis, Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis, and the fungal species Epidermophyton floccosum, Microsporum gypseum, and Sporothrix schenckii were more sensitive to the essential oils.

Plants used to treat malaria in Nyakayojo sub-county, western Uganda

AIM OF STUDY

We performed an ethnobotanical study of plants used to treat malaria in Nyakayojo sub-county in south western Uganda because malaria in this region, and in Uganda at large, is still the single most important reason for ill health and mortality. Two of the most vulnerable groups affected by malaria are young children and pregnant women and plants are commonly used in their treatment.

MATERIALS AND METHODS

Twenty-eight traditional birth attendants were interviewed about how they used plants to treat malaria. Review of the literature available on all species identified was undertaken.

RESULTS

Altogether 56 plant species were used by the informants, 48 of which have been identified to species level. Thirty-two (67%) of the species used by the respondents are documented for antimalarial use in other studies, and nearly half (44%) have documented anti-plasmodial activity. Fifty-five percent of the species were used by 2 or more of the respondents. The most commonly used species were Vernonia amygdalina, the indigenous Aloe species, Justicia betonica, Vernonia adoensis and Tithonia diversifolia. It was common to use more than one plant in a recipe (43%). The respondents had good knowledge of the symptom of malaria, and fairly good understanding of the causes.

CONCLUSION

The interviews show that the group of traditional birth attendants has an extensive and diverse knowledge on plants used in the treatment of malaria. The literature survey may indicate a possible explanation for the use of several plants.

Composition and in vitro antibacterial activity of essential oils from four Satureja species growing in Iran

The composition and in vitro antibacterial activity of essential oils from four Satureja species (S. bachtiarica, S. khuzistanica, S. mutica and S. rechingeri) growing in Iran were determined. According to the results of GC-FID and GC-MS analysis, all oil samples were principally composed of phenolic constituents (carvacrol and/or thymol) with the percentages ranging from 41.2% (S. bachtiarica) to 77.7% (S. rechingeri). Determining antibacterial activities by the disc diffusion method against two Gram-positive and two Gram-negative bacteria revealed the maximum activity against Bacillus cereus with a range of minimum inhibitory concentration values from 0.25 to 1 mg mL(-1) and minimum bactericidal concentration values from 0.5 to 1 mg mL(-1). The oils of S. khuzistanica and S. rechingeri appeared to be more active in general than those of other species. In conclusion, the essential oils of studied Satureja species have the potential to be considered as alternatives for synthetic food preservatives.

Comparative volatile oil composition of four Ocimum species from northern India

The hydrodistilled essential oils of Ocimum basilicum L. cvs. 'Vikarsudha' and 'CIM-Soumya', Ocimum sanctum L. cvs. 'Green' (CIM-Ayu) and 'Purple', Ocimum gratissimum L. and Ocimum kilimandscharicum Guerke have been studied by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Phenylpropanoids (65.2-77.6%) constituted the major proportion of the essential oil compositions of O. sanctum, O. basilicum and O. gratissimum, whilst oxygenated monoterpenes (72.7%) constituted the major proportion of the oil composition of O. kilimandscharicum. The essential oil compositions of cvs. 'Green' and 'Purple' of O. sanctum were almost the same, and both cultivars were dominated by eugenol (67.4% and 72.8%), β-elemene (11.0% and 10.9%), β-caryophyllene (7.3% and 8.4%) and germacrene D (2.4% and 2.2%), whilst the major components in O. basilicum cvs. 'Vikarsudha' and 'CIM-Soumya' were methyl chavicol (68.0% and 64.9%) and linalool (21.9% and 25.6%), along with bicyclogermacrene (2.0% and 0.7%) and α-terpineol (1.2% and 0.1%). Eugenol (77.2%), 1,8-cineole (7.6%), germacrene D (2.7%) and β-caryophyllene (1.7%) were identified as the major constituents of O. gratissimum. On the contrary, the essential oil from O. kilimandscharicum was mainly dominated by monoterpenoids (95.8%), represented by camphor (64.9%), limonene (8.7%), camphene (6.4%) and (E)-β-ocimene (3.0%).

Essential oils of four Rwandese hepatoprotective herbs: Gas chromatography-mass spectrometry analysis and antioxidant activities

Following an ethnobotanical survey in Southern Rwanda for hepatoprotective remedies, four food and medicinal plants, Crassocephalum vitellinum, Guizotia scabra, Microglossa pyrifolia and Ocimum lamiifolium, were selected for pharmacological and chemical investigations aiming to validate their reported properties. The chemical compositions of essential oils obtained from leaves were investigated by GC-MS; essential oils and methanolic extracts were evaluated for antioxidant activity by 1,1-diphenyl-2-picryhydrazyl (DPPH) and linoleic acid peroxidation assays. C. vitellinum [limonene (34.8%), (E)-β-ocimene (21.8%), β-pinene (8.5%), α-pinene (6.6%), myrcene (6.3%)], G. scabra [germacrene-d (25.5%), limonene (9.7%), (E)-β-ocimene (6.6%)], M. pyrifolia [germacrene-d (58.3%)] and O. lamiifolium [sabinene (12.2%), alpha phellandrene (11.6%)] volatile oils scavenge DPPH (10%, 39%, 27%, and 11% quercetin equivalents) and inhibit linoleic acid peroxidation (13%, 23%, 20%, and 13% Trolox® equivalents). The four methanolic extracts were quite active on the lipid peroxidation model (93%, 93%, 70%, and 67% Trolox equivalents) with modest activity on DPPH (5%, 10%, 8%, and 11% quercetin equivalents). These properties most probably participate in the four plants hepatoprotective activities reported in ethnopharmacological and/or pharmacological studies.