Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Menthol”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1990

Yeasts and fungi occurring in ensiled whole-crop maize and other ensiled vegetable crops.

The yeast flora of whole-crop maize ensiled for two weeks was predominated by Candida holmii, C. lambica, C. milleri, Hansenula anomala and Saccharomyces dairensis. Inoculation with other yeast species reported in the literature to prevail in maize or wheat silages did not alter the yeast flora. At 25 or 30 degrees C the ascomycetous fermentative species found at 20 degrees C were accompanied with ascomycetous non-fermentative fungi, i.c. Exophiala jeanselmei and Verticillium psalliotae, by the non-fermentative imperfect basidiomycetous yeast Rhodotorula mucilaginosa and by the weakly fermentative imperfect ascomycetous yeast Trichosporon adeninovorans. The yeast flora of other vegetable crops, ensiled at 20 degrees C for two weeks, was predominated by the same species that prevailed in ensiled maize, provided the crop did not contain mustard oils or menthol. If these compounds occurred in the crops, the yeast flora was predominated by nonfermentative species like Candida famata, Stephanoascus ciferrii, Rhodotorula minuta, Rh. rubra and Trichosporon cutaneum.

Animal Feed↗
PubMed1984

Histochemical localization of primary and secondary alcohol dehydrogenases in whole-body, freeze-dried sections of mice.

Whole-body sagittal sections of frozen, C57BL/6J, adult, male mice were used for the localization of primary and secondary alcohol dehydrogenases in most tissues of the body. The reduction of Nitro BT with NAD+ as coenzyme, as described originally by Hardonk (1965), was utilized for the generation of coloured final reaction deposits. Ethanol was used as a substrate for primary alcohol dehydrogenase; 2-propanol, alpha-methylbenzyl alcohol and 2-butanol were used as substrates for secondary alcohol dehydrogenase. Liver and bronchial epithelium showed the highest activities for both enzymes; oesophageal and upper gastric epithelium showed a high activity of primary alcohol dehydrogenase. Pyrazole, indazole and imidazole inhibited primary, but not secondary, alcohol dehydrogenase. Dimethylsulphoxide and menthol slightly inhibited both enzymes. Oleic acid, sulphydryl agents, p-chloromercuribenzoate, and copper sulphate also inhibited both enzymes. Slight inhibition of secondary dehydrogenase was observed on co-administration of several alcohols. As expected, N-nitrosonornicotine did not function as a substrate for alcohol dehydrogenases. When this compound was present in the histochemical incubation media, no activity was seen at any of the usual sites of these enzymes. The distribution of the alcohol dehydrogenase activities found in this study correlates with the distribution of radioactivity in oesophagus, bronchi and liver after administration of [14C]nitrosonornicotine. This suggests that the alcohol dehydrogenases may be involved in the metabolism of hydroxylated nitrosonornicotine, a metabolite of the most abundant known carcinogen in cigarette smoke.

Alcohol Oxidoreductases↗
PubMed1982

Analysis of creams. III. Application of gas--liquid chromatography. Part I.

The possibilities of the gas--liquid chromatographic analysis with flame ionization detection of creams of the o/w emulsion type were investigated. Interferences by cream base components in the determination of the active compounds were studied. It appeared to be possible to determine active compounds with a retention index lower than 1900 on ov-17 (e.g. methyl salicylate, menthol, thymol camphor) without clean-up of the cream samples; for the determination of compounds with retention indices between 1900 and 3700, a simple clean-up step suffices. The possible analysis of some of the cream base components together with the active compounds of the creams was investigated as well. Cetomacrogol emulsifying wax, lanette was sx and cetiol v could be determined easily, whether or not a sample clean-up step was incorporated.

Cetomacrogol↗
PubMed2005

Changes in the composition of phospholipid fatty acids and sterols of maize root in response to monoterpenes.

Terpenes are thought to be important in plant plant interactions because of their phytotoxic action on seed germination and growth. Herein, the effects of five volatile monoterpenes on root sterols and phospholipid fatty acid (PLFA) composition have been studied during maize seedling germination. The investigated monoterpenes (camphor, 1-8 cineole, geraniol, menthol, and thymol) were applied at their respective IC80 (concentration causing 80% inhibition). They quantitatively affected free sterols and PLFA composition, thus producing an increase in the percentage of unsaturated PLFAs, stigmasterol of the free sterol fraction, and saturated steryl ester fatty acids. Alcoholic and nonalcoholic monoterpenes appeared to have different modes of action. The former affected unsaturated fatty acid and stigmasterol to a greater extent, and accordingly they could interfere in seedling growth by changes in the membrane lipids.

Cell Membrane↗
PubMed2005

Estimation of transdermal permeation parameters in non-stationary diffusion experiments. Application to pre-treatment studies with terpenes.

PURPOSE: To estimate the applicability of transdermal drug permeation parameters in a finite-dose model for skin pre-treated with terpenes and to evaluate the enhancing effect of some terpene formulations on alprazolam permeation. METHODS: In vitro enhancement of alprazolam human skin permeation was investigated using a pretreatment with different terpene solutions. Vertical diffusion, Franz-type cells were used. Intrinsic drug permeation was also investigated. Transdermal permeation parameters were estimated from the permeation tabulates using different theoretical approaches for their calculation. Two groups of permeation parameters were calculated: modelistic (diffusion of a finite-dose of drug model) and parameters nondependent of a diffusional model. RESULTS: In control experiments, all approaches of data treatment satisfactorily described the experimental permeation profiles. When skin pre-treatment was investigated, the fitting of a mathematical sigmoid function was much better than the diffusional approach. Pre-treatment of the skin with Limonene dissolved in ethanol / propylene glycol and Menthol dissolved in propylene glycol increased 15 and 10 times respectively the permeation parameters of alprazolam. CONCLUSIONS: Using enhancers that are rapidly cleared from the skin, skin permeability does not remain constant during the permeation experiment and therefore it is not possible to calculate parameters that are usually true coefficients or definite values. In this case, non-modelistic parameters can be used to estimate an enhancing effect.

Administration, Cutaneous↗
PubMed1985

Metabolism of monoterpenes: oxidation of isopiperitenol to isopiperitenone, and subsequent isomerization to piperitenone by soluble enzyme preparations from peppermint (Mentha piperita) leaves.

Soluble enzyme extracts from peppermint leaves, when treated with polystyrene resin to remove endogenous monoterpenes and assayed with unlabeled substrates coupled with capillary gas-liquid chromatographic/mass spectrometric detection methods, were shown to oxidize isopiperitenol to isopiperitenone, and to isomerize isopiperitenone to piperitenone. The enzymes responsible for the monoterpenol dehydrogenation and the subsequent allylic isomerization were separated and partially purified by chromatography on Sephadex G-150, and were shown to have molecular weights of approximately 66,000 and 54,000, respectively. The general properties of the NAD-dependent dehydrogenase were examined, and specificity studies indicated that a double bond adjacent to the carbinol carbon was a required structural feature of the monoterpenol substrate. General properties of the isomerase were also determined, and it was demonstrated that the double bond migration catalyzed by this enzyme involved an intramolecular 1,3-hydrogen transfer. These enzymatic transformations represent two key steps in the metabolic pathway for the conversion of the initially formed cyclic olefin, (+/-)-limonene, to (-)-menthol and related monoterpenes characteristic of peppermint. Some stereochemical features of these reactions, and of the overall biogenetic scheme, are described.

Alcohol Oxidoreductases↗
PubMed1984

Receptor cell responses to odorants: similarities and differences among odorants.

An extensive exploration of the discriminating properties of olfactory receptors cells has been conducted in our laboratory through the statistical processing of single cell responses recorded in the frog's olfactory epithelium. Similarities between odorant stimulating properties could be demonstrated by comparing the complex response profiles of receptor cells, resulting in the concept of odorant groups which depicts consistent relationships found between some odorous compounds. The recording technique limits the number of odorants which can be tested and compared within the same series of experiments. Thus, based upon previous studies we have chosen a specific set of 20 odorants whose characteristics are known but, up to this time, have not been compared in the same experimental system. These odorants were: acetophenone, anisole, n-butanol, DL-camphor, cyclodecanone, 1,8-cineole, p-cymene, D-citronellol, n-heptanol, isoamyl acetate, isovaleric acid, D-limonene, methyl amylketone, L-menthol, phenol, thiophenol, pyridine, thymol, cyclohexanol, cyclohexanone. The pattern of similarities between these odorants, as delineated with the aid of correlation coefficient computation, factor analysis and non-hierarchical taxonomy, confirms the reality of several odorant groups previously suggested and describes their cross-relationships. The receptor mechanisms underlying these odorant groups are discussed. Because reliable prominent features of the olfactory stimulus space can be established on an objective basis, the findings are proposed as a reference for future studies on other aspects of olfactory discrimination.

Animals↗
PubMed1989

Analysis of avian cold receptor function.

The response characteristics of facial specific cold receptors of the pigeon were studied quantitatively by recording single unit activity from the trigeminal ganglion at various stimulus conditions and subsequent analysis of the discharge pattern. Responses to maintained temperatures as well as to cooling steps were qualitatively identical to those seen in the corresponding mammalian cold receptor populations, but avian cold receptors were generally less sensitive, particularly to dynamic stimuli. The major differences between avian and mammalian cold receptors were that avian cold units only occasionally discharged in periodic groups of impulses at constant temperatures and that there was no indication of cyclic receptor events being involved in the dynamic response to cooling, as it is the case in all mammalian cold sensors. Additionally, the temporal pattern of the grouped discharges was less regular in avian cold units. Application of calcium, EGTA and menthol revealed a comparatively low dependence of cold receptor function on external calcium. The results provide evidence that calcium-controlled processes and periodic receptor events contribute only insignificantly to the signal transduction of avian cold receptors. This indicates a different functional organization of the transducer processes of avian and mammalian cold receptors.

Action Potentials↗
PubMed1995

Effect of extracellular K+ on the intracellular free Ca2+ concentration in leech glial cells and Retzius neurones.

The effects of extracellular K+ on the intracellular free Ca2+ concentration ([Ca2+]i) of neuropile glial cells and Retzius neurones in intact segmental ganglia of the leech Hirudo medicinalis were investigated by using iontophoretically injected fura-2. In both cell types, an elevation of the extracellular K+ concentration ([K+]o) caused an increase in [Ca2+]i, which was blocked by Co2+, Ni2+ and menthol, whereas nicardipine, flunarizine, omega-conotoxin GVIA and omega-agatoxin IVA were ineffective. In Ca(2+)-free solution, the K(+)-induced [Ca2+]i increase was largely suppressed in neuropile glial cells and completely abolished in Retzius neurones. The results indicate that the K(+)-induced [Ca2+]i increase was mainly due to Ca2+ influx through voltage-dependent Ca2+ channels. The Ca2+ channels of the two cell types were activated at different membrane potentials but at the same [K+]o. In both cell types, the recovery from a K(+)-induced [Ca2+]i increase was unaltered in Na(+)-free solution, indicating that active Ca2+ transport across the plasma membrane is mediated by Na(+)-independent mechanisms.

Animals↗
PubMed1994

CHIRBASE, a molecular database for the separation of enantiomers by chromatography.

A selected review on the separation of the stereoisomers of menthol by gas chromatography serves to demonstrate a new approach to tackle the increasing number of publications on enantiomer separation. The graphical molecular database CHIRBASE covers information (structural, bibliographic and chromatographic data) on liquid chromatography, supercritical fluid chromatography and gas chromatography. CHIRBASE is based on standard database software, thus meeting the requirements of "state of the art" information management in the chemical and pharmaceutical industries and academia. The scrutiny required to create and maintain a factual database revealed that the information content of the contemporary literature with respect to chromatographic data requires improvement.

Chromatography↗
PubMed1990

Thresholds for odor and nasal pungency.

Detection thresholds were measured repeatedly for 11 chemicals in normosmic and anosmic subjects. The stimuli comprised the first eight members of the series of n-aliphatic alcohols, phenyl ethyl alcohol, pyridine, and menthol. Results showed that anosmics could detect, via pungency, all but phenyl ethyl alcohol reliably. In the aliphatic series, both odor and pungency thresholds declined with chain length in a way that implied dependence of both in part on phase distribution in the mucosa. Odor thresholds, however, declined more rapidly than pungency thresholds: the ratio of anosmics threshold/normosmics threshold increased from 23 for methanol to 10,000 for 1-octanol. The outcome of a scaling experiment employing normosmic subjects indicated that, with the exception of methanol and ethanol, pungency arose when perceived intensity reached a narrowly tuned criterion level. When thresholds were expressed as percentages of saturated vapor, an index of thermodynamic activity, thereby accounting for differences in solubility and in phase distribution in the mucosa among the various stimuli, both odor and pungency thresholds depicted a striking constancy across stimuli.

Adult↗
PubMed1990

The role of sucrose-sensitive neurons in ingestion of sweet stimuli by hamsters.

The relationship between sweet preference and activity in sucrose-sensitive chorda tympani nerve fibers was investigated in hamsters (Mesocricetus auratus). Without exception, hamsters increased consumption of aqueous solutions of nonsweet 0.1 M NaCl, 0.001 M quinine-HCl, 0.01 M citric acid, 0.001 M dithiothreitol, 0.01 M pyridine, 0.01 M 2-phenylethanol, 0.005 M i-amyl acetate, 0.01 M vanillin, half-saturated 1-menthol and 0.033 mM capsaicin if they were made sweet by adding 0.5 M sucrose. Since sucrose activates chorda tympani S fibers, activity in these nerve fibers may be sufficient for increased preference. To determine if S-fiber activity is necessary for preference, equally preferred sweet stimuli were presented to the tongue while recording responses of single chorda tympani fibers. S fibers were clearly activated by 0.03 M sucrose, 0.001 M Na saccharin, 0.01 M D-phenylalanine, 0.1 M glycine, 0.005 M dulcin and 0.03 M Na 2-mercaptoethanesulfonate but not by 0.01 M Ca cyclamate and 0.003 M Na 3-nitrobenzenesulfonate. Ca cyclamate weakly activated H fibers and Na 3-nitrobenzenesulfonate weakly activated N fibers. Thus, S-fiber chorda tympani activity may be sufficient but not necessary for sweet preference, which may be influenced by activity in fibers of other taste nerves.

Animals↗
PubMed1995

Taste and smell losses in HIV infected patients.

Human immunodeficiency virus (HIV-1) associated wasting is an increasingly common clinical manifestation of AIDS. The pathogenesis of wasting is multifactorial and includes reduced caloric intake as a major contributing mechanism. The perceptions of taste and smell play an important role in stimulating caloric intake and in optimizing nutrient absorption through cephalic phase reflexes. The purpose of this study was to evaluate the degree of losses in taste and smell function that occur in subjects infected with HIV. Taste and smell function was evaluated in 40 HIV infected individuals and 40 healthy control subjects matched for age, sex, race, smoking behavior, and number of years of education. Chemosensory tests administered to subjects included taste and smell detection thresholds, taste and smell memory tests, taste and smell discrimination tests, and taste and smell identification tasks. Significant differences were observed between experimental and control subjects in glutamic acid taste detection threshold (p < 0.001), quinine hydrochloride taste detection threshold (p < 0.001), menthol smell detection threshold (p < 0.001) and in the taste identification task (p = 0.006). Overall the results suggest abnormalities in the peripheral and central nervous systems, and subjective distortion of taste and smell. A significant correlation was not established between CDC classification of HIV infection and taste and smell function, although trends were observed suggesting worsening function with progression of HIV disease. These results document significant taste and smell losses in HIV infected subjects which may be of clinical significance in the development or progression of HIV associated wasting.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Prevalence of food allergy and intolerance in the adult Dutch population.

The prevalence of food allergy and intolerance (FA/FI) was studied in a random sample (n = 1483) of the Dutch adult population. First, the self-reported FA/FI reactions were investigated by questionnaire. Subsequently, in a clinical follow-up study, it was determined in how many cases this self-reported FA/FI could be objectively confirmed by double-blind placebo-controlled food challenge. More than 10% of the population (12.4%) reported FA/FI to specific food(s). Of the 144 subjects potentially available for the clinical follow-up study, 73 completed the whole protocol. In 12 subjects FA/FI could be confirmed by double-blind placebo-controlled food challenge. This indicates a minimum prevalence of FA/FI in the population of 0.8% (12 of 1483). Assuming that FA/FI is equal among participants, nonparticipants, and dropouts, the prevalence of FA/FI in the Dutch adult population is estimated to be 2.4%. The food (ingredients) involved included pork, white wine, and menthol. Two persons reacted to additives. In three persons glucose intolerance was observed. However, these specific intolerances probably do not reflect the distribution in the general population because the study population formed an extremely heterogeneous group, both with regard to the offending foods and the symptoms. The majority of the subjects had no serious complaints that required medical advice. We conclude that there is a gap between self-reported FA/FI and FA/FI that can be objectively confirmed by double-blind placebo-controlled food challenge.

Adolescent↗
PubMedDate not supplied

Cerebral chemosensory evoked potentials elicited by chemical stimulation of the human olfactory and respiratory nasal mucosa.

A stimulation method was employed by which chemosensory evoked potentials were recorded without tactile somatosensory contamination. The purpose of the study was to determine whether potential components evoked by stimulation of the chemoreceptors of the trigeminal nerve can be distinguished from those of the olfactory nerve. The stimulants (vanillin, phenylethyl alcohol, limonene, menthol, anethol, benzaldehyde, carbon dioxide and a mixture of vanillin and carbon dioxide) were presented in a randomized order to 13 volunteers. Chemosensory evoked potentials to substances which anosmics are unable to perceive (vanillin, phenylethyl alcohol) were termed olfactory evoked potentials; potentials to CO2, which effected no olfactory sensations were termed chemo-somatosensory potentials. Analysis of variance revealed that the different substances resulted in statistically significant changes in the amplitudes and latencies of the evoked potentials, and also in the subjective estimates of intensity. An increased excitation of the somatosensory system resulted in reduced latencies and enhanced amplitudes of the evoked potentials. Responses to the mixture of carbon dioxide and vanillin appeared significantly earlier (50-150 msec) than responses to either substance alone.

Adult↗
PubMedDate not supplied

Chromosome-damaging activity of saliva of betel nut and tobacco chewers.

Saliva of volunteers chewing betel quid, cured betel nut (Areca catechu), betel leaves (Piper betle), a mixture of quid ingredients (dried betel nut flakes, catechu, cardamon, lime, copra and menthol) and Indian tobacco was collected and examined for its genotoxic activity. Chromosome aberrations (chromatid breaks and chromatid exchanges) in Chinese hamster ovary (CHO) cells were used to estimate the genotoxic effect. No detectable levels of clastogenic activity were observed in the saliva of non-chewing individuals. After 5 min of chewing betel quid, betel nut, betel leaves, quid ingredients and Indian tobacco, the saliva samples showed relatively potent clastogenic activities. The addition of transition metals Mn2+ and Cu2+ to the saliva samples of betel nut and Indian tobacco chewers enhanced their clastogenic activities, whereas Fe3+ increased the clastogenicity of the betel nut saliva but decreased the genotoxic effect of the saliva of Indian tobacco chewers. After removal of the betel quid or its components from the mouth, the clastogenic activity disappeared within 5 min. The western-type chewing tobacco did not produce a genotoxic activity in the saliva of chewers. A possible association between the genotoxicity in the saliva of betel quid chewers and the development of oral, pharyngeal and esophageal carcinomas is discussed.

Areca↗
PubMed1990

AMS (acute mountain sickness), a vascular occlusive disease.

It is hypothesized that a cause of AMS could be vascular occlusion due to hemostatic plugs formed by DIPA (decompression-inducible platelet aggregation). Ex vivo experiments led to the current hypothesis that the rate of fibrin polymerization is accelerated by decompression and decelerated by compression. When experimental pressure is 253 torr (as at the top of Mt. Everest): (1) DIPA takes place independently of PO2; (2) ex vivo DIPA can be inhibited by menthol, thymol, piracetam and pentoxifylline. The experimental design was based on the premise that oppositely charged amino acid residues of adhesive site(s) are juxtaposed. Interaction of oppositely charged residues results in relaxation of electric constriction which causes the volume of the solution to increase. Because of the pressure-volume relationship, decompression alone can induce platelet aggregation. It is concluded that DIPA can be prevented and/or reversed by recompression, and by agents with a large electric dipole moment. It is suggested that the data presented here could be useful for DIPA investigations in vivo toward the prevention and/or alleviation of AMS.

Air Pressure↗
PubMed1991

Alcohol drinking and cigarette smoking: an exploration of the association in middle-aged men and women.

The association of alcohol and cigarette consumption was explored among 13,673 black or white persons aged 40-49 years, who received check-ups from mid-1979 to 1985. Alcohol use was strongly associated with number of cigarettes smoked per day, but not with tar-yield, mentholation and presence of filters. Duration of cigarette use, frequency and depth of inhalation, proportion of cigarette smoked and greater time from arising to first cigarette were significantly related to alcohol use in some but not all race-sex groups. Among smokers who consumed alcohol, liquor drinkers smoked the most cigarettes per day and wine drinkers the least. Thus, the association between alcohol drinking and cigarette smoking is strong in middle-aged persons but there are race- and sex-related disparities when specific aspects of smoking behaviour are considered.

Black or African American↗