Essential Oil Of Ocimum Gratissimum Research Articles

Potential use of Essential Oils from Cameroonian Plants for the Control of the Red Flour Weevil (Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae)

Animal feed is food constituted for breeding stock animals because it possesses vital nutrients for animal growth. Animal feed or their ingredients as constituted by cereal flour and are stored after formulation for ulterior breeds. These provender or cereal grains used are commonly attacked by storage insects principally of the genus Tribolium . Firstly, contact and ingestion test by two essential oils of aromatics plants Ocimum gratissimum L (Lamiaceae) and Xylopia aethiopica Dunal A. Rich (Annonaceae) were done firstly on adults and aged larvae of Tribolium castaneun . Secondly, the contact and inhalation test by three essential oils of the aromatic plants Annona senegalensis L. (Annonaceae), Lippia rugosa L. (Lamiaceae) and Hyptis spicigera Lam. (Verbenaceae) were done for the control larvae, young and aged adults of the red flour weevil Tribolium castaneum Herbst (Coleoptera : Tenebrionidae) very resistant pest to chemical pesticides. Essential oils of Ocimum gratissimum and Xylopia aethiopica have no contact and ingestion effect on adults of Tribolium castaneum ; their insecticidal activity is characterized mostly by their inhibition of the nymphosis of aged larvae of the same species. On the other hand contact and inhalation tests with crude essential oils of Lippia rugosa and Hyptis spicigera are the most promising because of their efficacy on the other life stages. They are more efficient, with 100% mortality, on larvae at early stages and young adults. On resistant aged larvae and adults, the insecticidal efficacy decreases but remains significant. Since this insect, Tribolium castaneum is the major pest of stored flours and provender, the incorporation of these promising essential oils in flours or in storage formulations of these foods for animals could contribute to their better cereal food conservation. The important and indispensable element of cereals for storage, growth and reproduction animal feed could be preserved from insects attack by use of natural product and may contribute to diminish toxicity of feeder, environmental pollution and the resistance phenomenon of insects.

Pharmacological evidence of calcium‐channel blockade by essential oil of Ocimum gratissimum and its main constituent, eugenol, in isolated aortic rings from DOCA‐salt hypertensive rats

Intravenous (i.v.) treatment of conscious DOCA-salt hypertensive rats with the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) induced a hypotensive effect that seems related to an active vascular relaxation rather than withdrawal of sympathetic tone. To corroborate this hypothesis, the present study examined the vascular effects of EOOG and its main constituent, eugenol (EUG) and the putative mechanisms underlying these effects. Additionally, the role of the vascular beta(2)-adrenergic mechanism in the mediation of EOOG-induced hypotension has also been investigated. In conscious DOCA-salt hypertensive rats, the EOOG-induced hypotension was reversible and remained unchanged by i.v. pretreatment with propranolol (2 mg/kg). In isolated aorta preparations with intact endothelium from DOCA-salt hypertensive rats, EOOG (1-1000 microg/mL) and EUG (0.006-6 mM) relaxed the phenylephrine-induced contraction similarly with IC(50) [geometric mean (95% confidence interval)] values of 226.9 (147.8-348.3) microg/mL and 1.2 (0.6-2.1) mm, respectively. Vasorelaxant effects of EOOG were significantly altered by removal of the vascular endothelium [IC(50) = 417.2 (349.5-497.8) microg/mL]. In a calcium-free medium, the CaCl(2)-induced contractions were significantly reduced and even abolished by EOOG at 300 and 1000 microg/mL, respectively, whereas EOOG (1000 microg/mL) did not have any significant effect on caffeine-induced contractions. Similar results were obtained with EUG (1.8 and 6 mM) on both CaCl(2)- and caffeine-induced contractions, respectively. The data suggest that hypotensive responses to EOOG in DOCA-salt hypertensive rats are due to an active vascular relaxation, which is partly dependent upon the integrity of the vascular endothelium and seems predominantly mediated through an inhibition of plasmalemmal Ca(2+) influx rather than Ca(2+)-induced Ca(2+) release from the sarcoplasmic reticulum.

Pharmacological evidence of calcium-channel blockade by essential oil of Ocimum gratissimum and its main constituent, eugenol, in isolated aortic rings from DOCA-salt hypertensive rats

Pharmacological evidence of calcium-channel blockade by essential oil of Ocimum gratissimum and its main constituent, eugenol, in isolated aortic rings from DOCA-salt hypertensive rats

Chemical composition and antimicrobial activity of the essential oil of Ocimum gratissimum L. growing in Eastern Kenya

Hydro-distilled volatile oils from the leaves of Ocimum gratissimum L. (Lamiaceae) from Meru district in Eastern Kenya were analysed by gas chromatography-mass spectrometry (GC-MS) and also evaluated for antimicrobial activity. The oil was dominated by monoterpens which accounted for 92.48%. This monoterpene fraction was characterized by a high percentage of eugenol (68.8%). The other major monoterpenes were methyl eugenol (13.21%), cis-ocimene (7.47%), trans-ocimene (0.94%),
-pinene (1.10%) and camphor (0.95%). The sesquiterpenes present in fairly good amounts were germacrene D (4.25%) and trans-caryophyllene (1.69%). The minor sesquiterpenes were -farnesene (0.85%) and
- bisabolene (0.74%). The antimicrobial activities of the essential oils were evaluated against both Gram positive (Staphylococcus aureus, Bacillus spp.) and Gram negative (Escherichia coli, Pseudomonas aeruginosae, Salmonella typhi, Klebisiella pneumoniae, Proteus mirabilis) bacteria and a pathogenic fungus Candida albicans. The oil had pronounced antibacterial and antifungal activities on all the microbes.

The effect of honey and surfactant type on the antibacterial properties of the leaf essential oil of Ocimum gratissimum Linn. against common wound-infecting organisms

Summary Honey is reported to have wound healing properties. This study aimed at investigating its effect as well as those of surfactants on the antibacterial activity of the essential oil of Ocimum gratissimum L. (ocimum oil). The antibacterial activity of dispersions of ocimum oil (2%) in methanol, honey, a macrogol blend, nonionic and ionic emulsifiers were assessed by cup–plate method using type bacteria and wound isolates. Honey enhanced the antibacterial activity of ocimum oil to a greater extent than the macrogol blend. The activity of ocimum oil emulsion in cetrimide (cationic) was lower than obtained for cetrimide solution. Emulsion of the oil in sodium lauryl sulphate (anionic) exhibited a slightly higher activity than the solution of the surfactant alone. Although Tween® 20 (nonionic) and aqueous methanol had no activity, the emulsion of the oil in Tween® 20 showed lesser activity than the oil solution in methanol. Honey’s inherent antibacterial activity, surfactant charge interaction and the effect of emulsification were adduced to the observed differences in antibacterial activity of the ocimum oil formulations. Our findings indicated honey as a suitable base for ocimum oil especially in the treatment of infected wounds. Caution is, however, desirable in the use of surfactants with ocimum oil.

Antileishmanial activity of Eugenol-rich essential oil from Ocimum gratissimum

Leishmaniasis is a group of diseases with a large spectrum of clinical manifestations caused by protozoans of the genus Leishmania. Here we demonstrate the leishmanicidal activity of the essential oil of Ocimum gratissimum as well as its main constituent, eugenol. The eugenol-rich essential oil of O. gratissimum progressively inhibited Leishmania amazonensis growth at concentrations ranging from 100 to 1000 μg/ml. The IC 50 (sub-inhibitory concentration) of the essential oil for promastigotes and amastigotes were respectively 135 and 100 μg/ml and the IC 50 of eugenol was 80 μg/ml for promastigote forms. L. amazonensis exposed to essential oil at concentrations corresponding to IC 50 for promastigotes and for amastigotes underwent considerable ultrastructural alterations, as shown by transmission electron microscopy. Two or more nuclei or flagella were observed in 31% and 23.3% of treated amastigote and promastigote forms, respectively, suggesting interference in cell division. Considerable mitochondrial swelling was observed in essential oil-treated promastigotes and amastigotes, which had the inner mitochondrial membrane altered, with a significant increase in the number of cristae; in some amastigotes the mitochondrial matrix became less electron-dense. The minimum inhibitory concentration for both promastigotes and amastigotes was 150 μg/ml. Pretreatment of mouse peritoneal macrophages with 100 and 150 μg/ml essential oil reduced the indices of association between promastigotes and the macrophages, followed by increased in nitric oxide production by the infected macrophages. The essential oil showed no cytototoxic effects against mammalian cells. This set of results suggests that O. gratissimum essential oil and its compounds could be used as sources for new antileishmanial drugs.

Vascular permeability-increasing effect of the leaf essential oil of <i>Ocimum gratissimum</i> Linn as a mechanism for its wound healing property

Persistent microvascular hyperpermeability to plasma proteins is a characteristic feature of normal wound healing. Does the leaf essential oil of Ocimum gratissimum heal wounds by promoting this feature? Evan’s blue dye (20mg/kg body weight) in normal saline was administered intravenously through marginal ear vein of experimental rabbits (n=5). Each animal served as its own control. One hour after Evan’s blue dye administration, 0.1ml each of Ocimum oil, histamine dihydrochloride (30µg/ml) and normal saline were randomly administered by intra-dermal injection at the prepared sites on each of the animals. Increase in vascular permeability was assessed by dye effusion test. Analysis of the differences in vascular permeability between treatment groups showed that, Ocimum oil, in intensity and duration, was significantly (p<0.05) more effective in increasing cutaneous capillary permeability over a 24h period after treatment. The ability of Ocimum oil in increasing vascular permeability may be one of

Temporal variation of chemical composition and relaxant action of the essential oil of Ocimum gratissimum L. (Labiatae) on guinea-pig ileum

The medicinal plant Ocimum gratissimum L. (Labiatae) is widely encountered in the Northeast of Brasil where it is used to treat digestive problems. Its leaves have an essential oil (EOOG) content whose chemical composition varies according to the time of plant collection. We have compared the effects of the EOOG, collected at 08:00 a.m. (EOOG8) and at 12:00 a.m. (EOOG12), on the relaxation of guinea-pig isolated ileum. Both EOOG8 and EOOG12 (30-300 microg/ml) reversibly relaxed the spontaneous tonus of the guinea-pig ileum in a concentration-dependent manner, with similar IC50 values (49.3 and 23.8 microg/ml, respectively). The magnitude of the decrease in resting tonus was similar to that of the recognised smooth muscle relaxant papaverine. EOOG8 and EOOG12 relaxed 60 mM KCl-precontracted preparations similarly (38.33 +/- 9.91 microg/ml and 35.53 +/- 6.70), whereas a significantly more potent relaxant effect of EOOG12 compared to EOOG8 was observed when tissues were contracted using 10 microM acetylcholine (IC50 values of 69.55 +/- 4.93 and 128.16 +/- 15.70 microg/ml, respectively; p < 0.05). The principal constituents of the essential oil, eugenol and cineole, also relaxed KCl-precontracted preparations, although they were less potent than EOOG, suggesting that they alone were not responsible for EOOG-induced relaxations. Our results show that the essential oil extracted from the leaves of O. gratissimum L., collected at different time periods, exerts significant relaxant effects on isolated guinea-pig ileum which may underlie the therapeutic action of the plant.

Enhanced Hypotensive Effects of the Essential Oil ofOcimum gratissimumLeaves and its Main Constituent, Eugenol, in DOCA-Salt Hypertensive Conscious Rats

The cardiovascular effects of intravenous (i.v.) treatment with the essential oil of Ocimum gratissimum (EOOG) and its main constituent, eugenol (Eug) were investigated in the experimental model of deoxycorticosterone acetate (DOCA-salt)-hypertensive rats. In both conscious DOCA-salt hypertensive rats and their uninephrectomized controls, i.v. bolus injections of EOOG (1 - 20 mg/kg) or Eug (1 - 10 mg/kg) induced dose-dependent hypotension and bradycardia. Treatment with DOCA-salt significantly enhanced the maximal decreases in mean aortic pressure (MAP) elicited by hexamethonium (30 mg/kg, i.v.) as well as the hypotensive responses to both EOOG and Eug without affecting the bradycardia. However, the enhancement of EOOG-induced hypotension in hypertensive rats remained unaffected by i.v. pretreatment with either hexamethonium (30 mg/kg) or methylatropine (1 mg/kg). These results show that i.v. treatment with EOOG or Eug dose-dependently decreased blood pressure in conscious DOCA-salt hypertensive rats, and this action is enhanced when compared with uninephrectomized controls. This enhancement appears related mainly to an increase in EOOG-induced vascular smooth relaxation rather than to enhanced sympathetic nervous system activity in this hypertensive model.

Studies on the acute and sub-chronic toxicity of the essential oil of Ocimum gratissimum L. leaf.

Oral and intra-peritoneal acute toxicity and the sub-chronic intra-peritoneal toxicity of the essential oil of Ocimum gratissimum Linn, Lamiaceae (Ocimum oil), was investigated. The acute toxicity test involved the oral and intra-peritoneal administration of graded doses of Ocimum oil prepared as a 4% v/v emulsion to 2 groups each of 30 rats and mice. LD50 and LD100 were determined for both routes and species. In the sub-chronic toxicity study, 25 male Sprague-Dawley rats were randomized into 4 test groups (treated with three graded sub-lethal doses of Ocimum oil prepared as a 4% v/v emulsion) and a control. Organs and blood samples were taken for analyses after a 30 day treatment period. A dose-dependent sedative effect of Ocimum oil was observed during the acute toxicity study in mice and rats and in the sub-chronic test in rats. Evidence of treatment, route, and dose-dependent toxicity were detected in both studies. Changes in weight of the testes, hearts, kidneys, intestines and lungs of the rats were statistically insignificant (ANOVA P < 0.05). Data analyses of blood biochemical, haematological and histopathological findings showed significant differences between control and treated groups and revealed that Ocimum oil is capable of invoking an inflammatory response that transits from acute to chronic on persistent administration. While the study revealed that Ocimum oil might be better tolerated when administered orally for systemic delivery, the oil has toxic potentialities that should not be overlooked.

Antinociceptive properties of the essential oil of Ocimum gratissimum L. (Labiatae) in mice.

We have investigated the antinociceptive effects of the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) in two classical models of pain in male Swiss mice (25-35 g), the writhing test and the formalin test. At doses of 30, 100 and 300 mg/kg (po), EOOG produced a dose-dependent inhibition (from 58.3 4.4 to 40.7 6.3, 36.4 3.6 and 24.6 3.6, respectively; N = 8-10, P<0.05) of acetic acid-induced writhing, causing up to a ~60% inhibition at the highest dose used, comparable to that obtained with indomethacin (10 mg/kg, po). At the same doses, EOOG predominantly inhibited the late (inflammatory) phase of the formalin-induced pain response (from 59.3 8.3 to 40.4 4.8, 23.2 2.8 and 25.3 5.5, respectively; N = 6, P<0.05), with a maximal reduction of ~60% of the control, although a significant reduction of the initial (neurogenic) phase was also observed at 300 mg/kg (from 62.5 6.07 to 37 5.9; P<0.05). On the basis of these data, we conclude that EOOG possesses interesting antinociceptive properties in the writhing and formalin tests. Due to the relatively low toxicity of EOOG, further detailed examination is strongly indicated for a better characterization of its pharmacological properties and its potential therapeutic value.

Antimicrobial study of essential oils of Ocimum gratissimum leaves and Zanthoxylum xanthoxyloides fruits from Cameroon

An investigation of antimicrobial activities of essential oils of fresh leaves of Ocimum gratissimum and the essential oil of the dried fruits of Zanthoxylum xanthoxyloides was carried out. The essential oils showed extensive inhibition zones and are, therefore, effective antimicrobial systems.

Relaxant effects of the essential oil of Ocimum gratissimum on isolated ileum of the guinea pig

The effects of the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) on guinea pig ileum were studied. EOOG (0.1–1000 μg/ml) reversibly and concentration-dependently relaxed the basal tone of the ileum and reversed the tonic contractions induced by 60 mM KCl and 10 μM acetylcholine, with IC 50 values of 23.8±5.2, 18.6±4.0 and 70.0±4.6 μg/ml, respectively. Our results show that EOOG exerts relaxant effects on intestinal smooth muscle, consistent with the popular use of the plant to treat gastrointestinal disorders.

Essential Oil of Ocimum gratissimum from Benin

The essential oils of Ocimum gratissimum were isolated from fresh aerial plant parts by steam distillation with yields from 0.2-0.9%. Analysis by GC and GC/MS identified 35 constituents, of which γ-terpinene (2.2-30.2%), p-cymene (13.5-37.1%) and thymol(2.3-32.1%) were the most abundant. Three samples were especially rich in p-cymene (38.2-47.1%), accompanied by γ-terpinene (2.2%) and myrcene (2.8%). Percentage of these compounds are included beetween 45-65%.

Chemical variation during daytime of constituents of the essential oil of Ocimum gratissimum leaves

Variation of chemical composition of the essential oil of Ocimum gratissimum eugenol type was studied for 11 h during the daytime. Microwave oven technique was used for the serial extraction and the obtained oils were analysed by GC/MS. A considerable variation was observed in the eugenol yield, 98% at 12.00 am. to 11% at 05.00 p.m. These results show the influence of the solar light on eugenol production and can be useful to indicate the optimal time for collection of the plant.

Studies on the essential oil bearing plants of Bangladesh. Part VI. Composition of the oil ofOcimum gratissimum L.

The composition of the essential oil of Ocimum gratissimum L. obtained from plants originating from Bangladesh and from plants introduced into Bangladesh from India is reported. The oil obtained from plants native of Bangladesh can be classified as thymol-type according to its thymol content (58.2%), while the oil obtained from plants introduced from India can be classified as eugenol/ocimene type according to its content of eugenol (66.5%) and ocimenes (18.9%). © 1998 John Wiley & Sons, Ltd.

Composition of the Essential Oil ofOcimum gratissimumGrown in Rwanda1

The essential oil of OCIMUM GRATISSIMUM, growing wild in Rwanda, was investigated by LSC, GLC, and GC-MS. The oil contained 35% thymol and 11% eugenol, which may indicate the occurrence of a new chemotype of the species. A large amount of hydrocarbons (42%) including 18% P-cymene was also found. The oil showed a relatively strong antimicrobial effect. The oil of O. GRATISSIMUM, cultivated in Rwanda from seeds collected in Cameroon, consisted of 47% thymol and only 0.3% eugenol. This sample contained 49% hydrocarbons, including 23% gamma-terpinene. Most of the constituents detected in the oil samples were not previously known to be present in the essential oil of O. GRATISSIMUM.

Biogenesis of the essential oil of Ocimum gratissimum (author's transl)

The quantitative and qualitative variability of compounds in the essential oil of Ocimum gratissimum has been examined during one growing period.