Flavor components of monoterpenes in citrus essential oils enhance the release of monoamines from rat brain slices

Abstract

Citrus essential oils have been utilized widely in traditional medicine, and there are various reports of actions such as effects on behavior and effects on pain stimulation response due to exposure. However, there are no reports concerning effects on neurotransmitters after ingestion, and uptake within the brain. We used brain tissue slices to investigate the effect of compounds in lemon essential oil on monoamine release. We investigated R-limonene, γ-terpinene and citral, major components of lemon essential oil; S-limonene, an isomer of R-limonene and metabolites of these compounds. The effect of each compound on monoamine release from brain tissue slices was found to be dose-dependent. R-Limonene and its S-isomer demonstrated differences with regard to monoamine release from brain tissue. S-Limonene and its metabolites were found to have a stronger effect than the R-isomer. Limonene metabolites taken up in vivo were also found to have a stronger effect on monoamine release than both the R-form and the S-form. In an investigation of dopamine release using stratum slices, terpinene and pinene demonstrated no clear differences in activity attributable to isomers. However, ρ-cymene, a γ-terpinene metabolite, was found to have a stronger effect than γ-terpinene. These results suggest that the metabolites of these monoterpene compounds contained in citrus essential oils have a stronger effect on monoamine release from brain tissue than the monoterpene compounds themselves.     

Conductor compounds of phenylpentane in Mycoleptodonoides aitchisonii mycelium enhance the release of dopamine from rat brain striatum slices

Monoterpene compound is a major component of essential oils in various aromatic species. Previous reports about the monoterpene compound linalool and its effect on the brain neurotransmitters glutamic acid, GABA and acetylcholine, but not catecholamines, have been reported. In this study, we investigated the effect of linalool or conductor compounds of phenylpentane, including 1-phenyl-3-pentanol and 1-phenyl-3-pentanone, on dopamine release using rat striatal slices. The edible mushroom Mycoleptodonoides aitchisonii belongs to the Climacodontaceae family, and its cultivate medium or mycelium contains derivatives of the fragrant conductor compound, phenylpentane. Compared to basal levels, 2.5 microg linalool increased dopamine from striatal slices 3-fold. A 4-fold increase in dopamine release resulted from 2.5 microg 1-phenyl-3-pentanol administration, while a half dose of this compound induced a 2.5-fold increase. A greater than 2-fold increase resulted with 2.5 microg 1-phenyl-3-pentanone. These data indicate that striatum has sensitivity for these fragrant compounds and different releasing effects result with differ structures. These actions may affect other neurotransmitters and influence brain function.     

Conductor Compounds of Phenylpentane in Mycoleptodonoides aitchisonii Mycelium Enhance the Release of Dopamine from Rat Brain Striatum Slices

Abstract

Monoterpene compound is a major component of essential oils in various aromatic species. Previous reports about the monoterpene compound linalool and its effect on the brain neurotransmitters glutamic acid, GABA and acetylcholine, but not catecholamines, have been reported. In this study, we investigated the effect of linalool or conductor compounds of phenylpentane, including 1-phenyl-3-pentanol and 1-phenyl-3-pentanone, on dopamine release using rat striatal slices. The edible mushroom Mycoleptodonoides aitchisonii belongs to the Climacodontaceae family, and its cultivate medium or mycelium contains derivatives of the fragrant conductor compound, phenylpentane. Compared to basal levels, 2.5 μg linalool increased dopamine from striatal slices 3-fold. A 4-fold increase in dopamine release resulted from 2.5 μg 1-phenyl-3-pentanol administration, while a half dose of this compound induced a 2.5-fold increase. A greater than 2-fold increase resulted with 2.5 μg 1-phenyl-3-pentanone. These data indicate that striatum has sensitivity for these fragrant compounds and different releasing effects result with differ structures. These actions may affect other neurotransmitters and influence brain function.     

Constituents of the essential oil of sea fennel (Crithmum maritimum L.) growing wild in Turkey

The essential oils isolated by hydrodistillation from freshly obtained aerial parts of sea fennel (Crithmum maritimum L.) were found to be a yellow liquid, obtained in a yield of 0.2% (vol/wt) based on wet weight. The essential oils obtained from young leaves and branches of C. maritimum, collected at two different locations in Turkey (Sipahili and Yesilovacik), were analyzed by gas chromatography-mass spectrometry. Twenty-three components were identified accounting for more than 99% of the total oils. The oils contained mainly monoterpenes, amounting to 89.0% and 99.6%, respectively, of the oils, with gamma-terpinene (36% and 32%), beta-phellandrene (21% and 22%), and sabinene (13% and 9%) as the main components.     

Chemical composition and antifungal activity of rosemary (Rosmarinus officinalis L.) oil from Turkey

The essential oil of the aerial parts of Rosmarinus officinalis collected from Konya, Turkey was analysed by gas chromatography and gas chromatography-mass spectrometry. The oil yield of dried plant (volume/dry weight) obtained by hydrodistillation was 1.9%. Twenty compounds representing 99.93% of the oils were identified. The main constituents of the oils were p-cymene (44.02%), linalool (20.5%), gamma-terpinene (16.62%), thymol (1.81%), beta-pinene (3.61%), alpha-pinene (2.83%) and eucalyptol (2.64%). The oil consisted of monoterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpene hydrocarbons. Also, the inhibition effect of rosemary oil was investigated against Alternaria alternata, Botrytis cinerea and Fusarium oxysporum. The experiment was carried out in vitro using disc diffusion to investigate the antifungal action of the oil. Oil tested on potato dextrose agar plates exhibited an inhibitory effect. The extent of inhibition of fungal growth varied depending on the levels of essential oil used in experiment.     

Ethanol-induced inhibition of GABA release from LS and SS mouse brain slices

The effects of ethanol on K+-stimulated and spontaneous release of gamma-aminobutyric acid (GABA) were studied in cortical and cerebellar brain slices obtained from long-sleep (LS) and short-sleep (SS) mice. A superfusion technique was used. Tissue slices were perfused with ethanol (0-515 mM) for 20 min. Ethanol inhibited K+-stimulated 3H-GABA release at lower concentrations in LS cortical slices than in SS slices. Little or no inhibition of K+-stimulated 3H-GABA release was seen in both LS and SS cerebellar slices. The spontaneous release of 3H-GABA was inhibited to equal degrees in LS and SS cerebellar slices but was unaffected in cortical slices, at the concentrations used. The possibility that ethanol inhibits 3H-GABA release by stimulating prostaglandin production was partially tested by assessing the effects of prostaglandin F2 alpha (PGF2 alpha) on 3H-GABA release in cortical and cerebellar slices. No effect of PGF2 alpha on 3H-GABA release was seen in either brain region. These results support the notion that ethanol may elicit some of its actions by inhibiting neurotransmitter release. This effect appears to be influenced by genotype and brain region.     

The effects of essential oils and aqueous tea infusions of oregano (Origanum vulgare L. spp. hirtum), thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) on the copper-induced oxidation of human low-density lipoproteins

In this study, the antioxidative capacity effect of essential oils and aqueous tea infusions obtained from oregano, thyme and wild thyme on the oxidation susceptibility of low-density lipoproteins (LDL) has been studied. The results indicate a dose-dependent protective effect of the tested essential oils and aqueous tea infusions on the copper-induced LDL oxidation. The protective effect of essential oils is assigned to the presence of phenolic monoterpenes, thymol and carvacrol, which are identified as the dominant compounds in these essential oils. The strong protective effect of aqueous tea infusions is proposed to be the consequence of large amounts of polyphenols, namely rosmarinic acid and flavonoids (quercetin, eriocitrin, luteolin-7-O-glucoside, apigenin-7-O-glucoside, luteolin, apigenin), with the most pronounced effect in the case of oregano. These findings may have implications for the effect of these compounds on LDL in vivo.     

Flavonoid intake and bone health

Flavonoids, found in a wide diversity of plant foods from fruits and vegetables, herbs and spices, essential oils, and beverages, have the most potential of dietary components for promotion of bone health beyond calcium and vitamin D. Recent epidemiological studies show flavonoid consumption to have a stronger association with bone than general fruit and vegetable consumption. Bioactive flavonoids are being assessed for properties beyond their chemical antioxidant capacity, including anti-inflammatory actions. Some have been reported to enhance bone formation and to inhibit bone resorption through their action on cell signaling pathways that influence osteoblast and osteoclast differentiation. Future research is needed to determine which of the flavonoids and their metabolites are most effective and at what dose, as well as the mechanism of modulating cellular events, in order to set priorities for clinical trials.     

Mosquito larvicidal activity of botanical-based mosquito repellents

The larvicidal activity of 4 plant essential oils--innamon oil, lemon eucalyptus oil, sandalwood oil, and turmeric oil--previously reported as insect repellents was evaluated in the laboratory against 4th instars of Aedes albopictus, Ae. aegypti, and Culex pipiens. Sandalwood oil appeared to be the most effective of the larvicides, killing larvae of all 3 mosquito species in relatively short times. The values of LT50 and LT90 at the application dosage (0.2 mg/ml) were 1.06 +/- 0.11 and 3.24 +/- 0.14 h for Ae. aegypti, 1.82 +/- 0.06 and 3.33 +/- 0.48 h for Ae. albopictus, and 1.55 +/- 0.07 and 3.91 +/- 0.44 h for Cx. pipiens, respectively. Chemical compositions of these essential oils were also studied, and the lavicidal activity of their major ingredient compounds was compared with that of each of the essential oils. The acute toxicity of the 4 essential oils to fathead minnows was also evaluated. The safe use of these natural plant essential oils in future applications of mosquito control was discussed.     

Enhancing effect of Mycoleptodonoides aitchisonii on synthesis of nerve growth factor and releasing dopamine in the rat brain

The effects of edible mushroom Mycoleptodonoides aitchisonii on the synthesis of nerve growth factor (NGF) and neurotransmitter metabolism in rat brain were examined in Wistar strain rats fed a controlled diet for 14 days. Then each brain was dissected to detect the levels of neurotransmitters and NGF in various regions. Dopamine concentration in the cerebral cortex was 1.5-fold significantly increased in the M. aitchisonii feeding group than the control group. However, NGF concentration of the M. aitchisonii feeding was significantly low. NGF concentration in this remaining area of brain from where the cerebral cortex, striatum, hippocampus, cerebellum, hypothalamus and amygdala were removed was significantly higher in the M. aitchisonii feeding. At the same time, in the striatum, the dopamine metabolite DOPAC was significantly increased in the M. aitchisonii feeding. Thereafter, we measured dopamine release from striatal slices using aqueous extract of M. aitchisonii, there was an enhancing effect on dopamine release. These results suggested that M. aitchisonii has enhancing effect on the synthesis of NGF and catecholamine metabolites in the rat brain.     

Enhancing Effect ofMycoleptodonoides aitchisoniion Synthesis of Nerve Growth Factor and Releasing Dopamine in the Rat Brain

Abstract

The effects of edible mushroom Mycoleptodonoides aitchisonii on the synthesis of nerve growth factor (NGF) and neurotransmitter metabolism in rat brain were examined in Wistar strain rats fed a controlled diet for 14 days. Then each brain was dissected to detect the levels of neurotransmitters and NGF in various regions. Dopamine concentration in the cerebral cortex was 1.5-fold significantly increased in the M. aitchisonii feeding group than the control group. However, NGF concentration of the M. aitchisonii feeding was significantly low. NGF concentration in this remaining area of brain from where the cerebral cortex, striatum, hippocampus, cerebellum, hypothalamus and amygdala were removed was significantly higher in the M. aitchisonii feeding. At the same time, in the striatum, the dopamine metabolite DOPAC was significantly increased in the M. aitchisonii feeding. Thereafter, we measured dopamine release from striatal slices using aqueous extract of M. aitchisonii, there was an enhancing effect on dopamine release. These results suggested that M. aitchisonii has enhancing effect on the synthesis of NGF and catecholamine metabolites in the rat brain.     

Antifungal activity of essential oils against fungi isolated from air

Fungal contamination of indoor air is an issue of increasing public health concern. Essential oils have been demonstrated to have antifungal capabilities, but there are limited studies investigating the efficacy of essential oils against fungi relevant to air quality. This study provides a preliminary screening of the antifungal properties of clove, lavender and eucalyptus essential oils against a range of fungal species isolated from environmental air samples. The ability of the essential oils to inhibit fungal growth was examined using the disk diffusion assay on malt extract agar and was compared with vinegar, bleach and limonene, with phenol as a positive control. Results identified essential oils which demonstrated antifungal potential against species of environmental origin. Clove oil was found to be most efficacious, with eucalyptus and lavender oils showing some antifungal potential albeit less broad spectrum and with less persistence over time in this assay. All essentials oils performed better than traditional cleaning compounds such as vinegar. Clove oil would be a suitable candidate for further research to validate its use in improving indoor air quality. Further research should next take into consideration the practical application method, concentration and long-term persistence of antifungal properties.     

Microbial flora on restaurant beverage lemon slices

Restaurateurs often place a lemon slice on the rim of a beverage glass, or afloat in the beverage, as a flavor-enhancer or a decorative garnish. The handling of the lemons before their placement in the beverage may not follow sanitary procedures. The study reported here investigated whether beverage lemon slices contain microbial contamination that could be consumed by a restaurant patron. Swabbed samples of the flesh and rind of lemon slices on the rims of beverage glasses were analyzed for microbial contents. Seventy-six lemons from 21 restaurants were sampled during 43 visits. Fifty-three (69.7 percent) of the lemon slices produced microbial growth. Twenty-three (30.3 percent) of the lemon slices produced no microbial growth. A total of 25 different microbial species were recovered from the samples.     

Monoamine reuptake inhibition and mood-enhancing potential of a specified oregano extract

A healthy, balanced diet is essential for both physical and mental well-being. Such a diet must include an adequate intake of micronutrients, essential fatty acids, amino acids and antioxidants. The monoamine neurotransmitters, serotonin, dopamine and noradrenaline, are derived from dietary amino acids and are involved in the modulation of mood, anxiety, cognition, sleep regulation and appetite. The capacity of nutritional interventions to elevate brain monoamine concentrations and, as a consequence, with the potential for mood enhancement, has not been extensively evaluated. The present study investigated an extract from oregano leaves, with a specified range of active constituents, identified via an unbiased, high-throughput screening programme. The oregano extract was demonstrated to inhibit the reuptake and degradation of the monoamine neurotransmitters in a dose-dependent manner, and microdialysis experiments in rats revealed an elevation of extracellular serotonin levels in the brain. Furthermore, following administration of oregano extract, behavioural responses were observed in mice that parallel the beneficial effects exhibited by monoamine-enhancing compounds when used in human subjects. In conclusion, these data show that an extract prepared from leaves of oregano, a major constituent of the Mediterranean diet, is brain-active, with moderate triple reuptake inhibitory activity, and exhibits positive behavioural effects in animal models. We postulate that such an extract may be effective in enhancing mental well-being in humans.     

Ethanol-induced inhibition of norepinephrine release from brain slices obtained from LS and SS mice

The effects of ethanol or prostaglandin E₂ (PGE₂) on K⁺-ion-stimulated or spontaneous (³H)-norepinephrine release were assessed in slices prepared from cortex and cerebellum of long-sleep (LS) and short-sleep (SS) mice. These lines were selectively bred for differences in ethanol-induced sleep time. Ethanol inhibited K⁺-stimulated release from LS cortical slices at lower concentrations than that required to inhibit release from SS cortical slices. Spontaneous release, on the other hand, was enhanced at lower ethanol concentrations in SS cortical slices. Ethanol inhibited K⁺-stimulated release equally in LS and SS cerebellar slices. Similarly, ethanol increased spontaneous release equally in LS and SS cerebellar slices. Thus, genotype and brain region influence the effect of ethanol on norepinephrine release. Since PGE₂ has been reported to inhibit norepinephrine release, the effect of PGE₂ on K⁺-stimulated norepinephrine release was examined in LS and SS cortical slices. PGE₂ inhibited norepinephrine release equally in the two mouse lines. These data indicate that ethanol may elicit some of its depressant effects by altering norepinephrine release. The difference between the lines in inhibition of release probably does not involve differences in sensitivity to PGE₂. Differences in ethanol-induced PGE₂ production could, however, explain the differences in sensitivity of LS and SS cortical slices to ethanol-induced inhibition of K⁺-stimulated norepinephrine release.     

Biochemical Studies on the Toxicity of Tetraethyl Lead and Other Organo-Lead Compounds

The actions of purified tetra-, tri-, and di-ethyl lead on rats and rat brain slices and brain brei have been examined. A method based on a reaction with dithizone and capable of estimating tri- and di-ethyl tin in rat tissues has been developed.

After injection into rats tetraethyl lead is converted into triethyl lead and this is responsible for the toxic effects. Diethyl lead is much less toxic and the effects are different. The utilization of lactate and the oxidation of glucose by brain brei and slices respectively are inhibited by triethyl lead. A similar effect is seen in slices taken from rats poisoned with tetra- or tri-ethyl lead. Rat liver cell microsomes readily convert tetraethyl to triethyl lead and the latter is stable and remains in the animal tissues for several days. The concentration of triethyl lead in the brain is not high in comparison with other tissues but brain tissue appears to be unduly sensitive to its toxic action.

Neither tetra- nor tri-ethyl lead reacts with B.A.L. or ethylene-diamine-tetra-acetic acid (E.D.T.A.). Diethyl lead reacts with B.A.L. but not with E.D.T.A.

     

EFFECT OF CORTISOL ON GLUCOSE METABOLISM

Cortisol reduces glucose metabolism by rat adipose tissue slices and partially inhibits the glucose metabolism stimulating effect of epinephrine. Cortisol has no influence on the release of unesterified fatty acids by adipose tissue slices.     

Antioxidative properties of water extracts obtained from herbs of the species Lamiaceae

Essential oils and extracts of aromatic herbs obtained by organic solvents have been extensively studied for their antioxidant activity in lipid substrates. Very little is known about the possible presence of antioxidants in polar extracts from herbs used in preparation of infusions and decoctions. In this work water extracts of six different herbs of the Lamiaceae family (dittany, lemon balm, mint, sage, sideritis and sweet marjoram) were prepared. The extracts were examined for their effect against lipid oxidation in comparison to a tea water extract. Sweet marjoram, sage and dittany extracts were found to have a remarkable capacity in retarding lipid oxidation. Examination by thin-layer chromatography of the freeze-dried extracts, before and after hydrolysis, showed that the extracts were rich in bound forms of phenolic compounds such as hydroxycinnamic acids and flavonoids. Rosmarinic and caffeic acids were detected in all extracts with the exception of those from mint and sideritis. These results indicate that certain plants used for the preparation of infusions could be further studied like tea as sources of antioxidants.     

锰对神经细胞内质网应激信号分子的影响

目的 观察锰对大鼠脑片神经细胞内质网应激信号分子的影响及其与细胞凋亡的关系. 方法 以胎大鼠脑片为模型,用400μmo/L锰分别处理脑片612、18、24 h后,检测培养液中乳酸脱氢酶（LDH）的释放量,神经细胞凋亡率以及脑片中GRP78、CHOP及caspase 12的表达. 结果 随着锰处理时间的增加,脑片细胞损伤明显,LDH释放量,细胞凋亡率和GRP78、CHOP及caspase 12的表达均逐渐上升. 结论 锰可以时间依赖性地活化内质网应激信号分子,促使细胞凋亡.     

Antioxidative properties of water extracts obtained from herbs of the species Lamiaceae

Essential oils and extracts of aromatic herbs obtained by organic solvents have been extensively studied for their antioxidant activity in lipid substrates. Very little is known about the possible presence of antioxidants in polar extracts from herbs used in preparation of infusions and decoctions. In this work water extracts of six different herbs of the Lamiaceae family (dittany, lemon balm, mint, sage, sideritis and sweet marjoram) were prepared. The extracts were examined for their effect against lipid oxidation in comparison to a tea water extract. Sweet marjoram, sage and dittany extracts were found to have a remarkable capacity in retarding lipid oxidation. Examination by thin-layer chromatography of the freeze-dried extracts, before and after hydrolysis, showed that the extracts were rich in bound forms of phenolic compounds such as hydroxycinnamic acids and flavonoids. Rosmarinic and caffeic acids were detected in all extracts with the exception of those from mint and sideritis. These results indicate that certain plants used for the preparation of infusions could be further studied like tea as sources of antioxidants.