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 487 records · Page 27Linked to original sources
PubMed1979

Metabolism of Monoterpenes: Demonstration of (+)-Neomenthyl-beta-d-Glucoside as a Major Metabolite of (-)-Menthone in Peppermint (Mentha Piperita).

(-)-Menthone, the major monoterpene component of the essential oil of maturing peppermint (Mentha piperita L.) leaves (6 micromoles per leaf) is rapidly metabolized at the onset of flowering with a concomitant rise in the level of (-)-menthol (to about 2 micromoles per leaf). Exogenous (-)-[G-(3)H]menthone is converted into (-)-[(3)H]menthol as the major steam-volatile product in leaf discs in flowering peppermint (10% of incorporated tracer); however, the major portion of the incorporated tracer (86%) resided in the nonvolatile metabolites of (-)-[G-(3)H]menthone. Acid hydrolysis of the nonvolatile material released over half of the radioactivity to the steamvolatile fraction, and the major component of this fraction was identified as (+)-neomenthol by radiochromatographic analysis and by synthesis of crystalline derivatives, thus suggesting the presence of a neomenthyl glycoside. Thin layer chromatography, ion exchange chromatography, and gel permeation chromatography on Bio-Gel P-2 allowed the purification of the putative neomenthyl glycoside, and these results suggested that the glycoside contained a single, neutral sugar residue. Hydrolysis of the purified glycoside, followed by reduction of the resulting sugar moiety with NaB(3)H(4), generated a single labeled product that was subsequently identified as glucitol by radio gas-liquid chromatography of both the hexatrimethylsilyl ether and hexaacetate derivative, and by crystallization to constant specific radioactivity of both the alditol and the corresponding hexabenzoate. These results, along with studies on the hydrolysis of the glycoside by specific glycosidases, strongly suggest that (+)-neomenthyl-beta-d-glucoside is a major metabolite of (-)-menthone in flowering peppermint. This is the first report on the occurrence of a neomenthyl glycoside, and the first evidence implicating glycosylation as an early step in monoterpene catabolism.

Journal Article↗
PubMed1982

Demonstration of the Intercellular Compartmentation of l-Menthone Metabolism in Peppermint (Mentha piperita) Leaves.

The metabolism of l-menthone, which is synthesized in the epidermal oil glands of peppermint (Mentha piperita L. cv. Black Mitcham) leaves, is compartmented; on leaf maturity, this ketone is converted to l-menthol and l-menthyl acetate in one compartment, and to d-neomenthol and d-neomenthyl glucoside in a separate compartment. All of the enzymes involved in these reactions are soluble when prepared from whole-leaf homogenates. Mechanical separation of epidermal fragments from the mesophyll, followed by preparation of the soluble enzyme fraction from each tissue, revealed that the neomenthol dehydrogenase and the glucosyl transferase resided specifically in the mesophyll layer, whereas the menthol dehydrogenase and substantial amounts of the acetyl transferase were located in the epidermis, presumably within the epidermal oil glands. These results suggest that the compartmentation of menthone metabolism in peppermint leaves is intercellular, not intracellular.

Journal Article↗
PubMed1984

Metabolism of Monoterpenes : Early Steps in the Metabolism of d-Neomenthyl-beta-d-Glucoside in Peppermint (Mentha piperita) Rhizomes.

Previous studies have shown that the monoterpene ketone l-[G-(3)H] menthone is reduced to the epimeric alcohols l-menthol and d-neomenthol in leaves of flowering peppermint (Mentha piperita L.), and that a portion of the menthol is converted to menthyl acetate while the bulk of the neomenthol is transformed to neomenthyl-beta-d-glucoside which is then transported to the rhizome (Croteau, Martinkus 1979 Plant Physiol 64: 169-175). Analysis of the disposition of l-[G-(3)H]menthone applied to midstem leaves of intact flowering plants allowed the kinetics of synthesis and transport of the monoterpenyl glucoside to be determined, and gave strong indication that the glucoside was subsequently metabolized in the rhizome. Studies with d-[G-(3)H]neomenthyl-beta-d-glucoside as substrate, using excised rhizomes or rhizome segments, confirmed the hydrolysis of the glucoside as an early step in metabolism at this site, and revealed that the terpenoid moiety was further converted to a series of ether-soluble, methanol-soluble, and water-soluble products. Studies with d-[G-(3)H]neomenthol as the substrate, using excised rhizomes, showed the subsequent metabolic steps to involve oxidation of the alcohol back to menthone, followed by an unusual lactonization reaction in which oxygen is inserted between the carbonyl carbon and the carbon bearing the isopropyl group, to afford 3,4-menthone lactone. The conversion of menthone to the lactone, and of the lactone to more polar products, were confirmed in vivo using l-[G-(3)H]menthone and l-[G-(3)H]-3,4-menthone lactone as substrates. Additional oxidation products were formed in vivo via the desaturation of labeled neomenthol and/or menthone, but none of these transformations appeared to lead to ring opening of the p-menthane skeleton. Each step in the main reaction sequence, from hydrolysis of neomenthyl glucoside to lactonization of menthone, was demonstrated in cell-free extracts from the rhizomes of flowering mint plants. The lactonization step is of particular significance in providing a means of cleaving the p-menthane ring to afford an acyclic carbon skeleton that can be further degraded by modifications of the well-known beta-oxidation sequence.

Journal Article↗
PubMed2005

The contribution of TRPM8 channels to cold sensing in mammalian neurones.

Different classes of ion channels have been implicated in sensing cold temperatures at mammalian thermoreceptor nerve endings. A major candidate is TRPM8, a non-selective cation channel of the transient receptor potential family, activated by menthol and low temperatures. We investigated the role of TRPM8 in cold sensing during transient expression in mouse cultured hippocampal neurones, a tissue that lacks endogenous expression of thermosensitive TRPs. In the absence of synaptic input, control hippocampal neurones were not excited by cooling. In contrast, all TRPM8-transfected hippocampal neurones were excited by cooling and menthol. However, in comparison to cold-sensitive trigeminal sensory neurones, hippocampal neurones exhibited much lower threshold temperatures, requiring temperatures below 27 degrees C to fire action potentials. These results directly demonstrate that expression of TRPM8 in mammalian neurones induces cold sensing, albeit at lower temperatures than native TRPM8-expressing neurones, suggesting the presence of additional modulatory mechanisms in the cold response of sensory neurones.

Animals↗
PubMed1995

Microbial degradation of monoterpenes in the absence of molecular oxygen.

Anaerobic degradation of natural monoterpenes by microorganisms was evaluated by using Pseudomonas citronellolis DSM 50332 and enrichment cultures containing nitrate as an electron acceptor. P. citronellolis grew anaerobically on 3,7-dimethyl-1-octanol and citronellol but not on geraniol, nerol, and alicyclic monoterpenes. In contrast, several a-, mono-, and bicyclic monoterpenes supported microbial growth and denitrification in enrichment cultures. We found that consumption of linalool, menthol, menth-1-ene, alpha-phellandrene, limonene, 2-carene, alpha-pinene, and fenchone in enrichment cultures depended on the presence of living microorganisms and nitrate. In these experiments, the ratios of number of electrons derived from complete substrate oxidation to number of electrons derived from nitrate reduction ranged from 1.2:1 to 2.9:1. Microbial degradation was accompanied by the formation of small traces of monoterpenes, which were characterized by gas chromatography-mass spectroscopy. The formation of geraniol and geranial from linalool suggested that a 3,1-hydroxyl-delta 1-delta 2-mutase reaction initiates linalool degradation. Seven strains of motile, oval to rod-shaped, facultatively denitrifying bacteria were isolated on agar bottle plates by using linalool, menthol, menth-1-ene, alpha-phellandrene, 2-carene, eucalyptol, and alpha-pinene as sole carbon and energy sources.

Anaerobiosis↗
PubMed1991

Acute behavioural comparisons of toluene and ethanol in human subjects.

A comparison of toluene and ethanol (EtOH) induced changes in central nervous system (CNS) function and symptoms were evaluated in two studies, and when possible the effects of toluene were expressed in EtOH equivalent units. The toluene concentrations were 0, 75, and 150 ppm, bracketing the American Conference of Governmental Industrial Hygienists threshold limit value (ACGIH TLV) of 100 ppm. The socially relevant EtOH doses were 0.00, 0.33, and 0.66 g EtOH/kg body weight, equivalent to two and four 3.5% 12 ounce beers. Forty two paid college students were used in each study. In the first study, subjects were exposed to toluene and an odour masking agent menthol (0.078 ppm) for seven hours over three days. In the second study EtOH or a placebo was administered at 1530 across three days also in the presence of menthol. Verbal and visual short term memory (Sternberg, digit span, Benton, pattern memory), perception (pattern recognition), psychomotor skill (simple reaction time, continuous performance, symbol-digit, hand-eye coordination, finger tapping, and critical tracking), manual dexterity (one hole), mood (profile on mood scales (POMS), fatigue (fatigue checklist), and verbal ability were evaluated at 0800, 1200, and 1600. Voluntary symptoms and observations of sleep were collected daily. A 3 x 3 latin square design evaluated solvent effects simultaneously controlling for learning and dose sequence. An analysis of variance and test for trend were performed on am-pm differences reflecting an eight hour workday and on pm scores for each solvent, in which subjects were their own control Intersubject variation in absorbance was monitored in breath. A 5 to 10% decrement was considered meaningful if consistent with a linear trend at p less than 0.05. At 150 ppm toluene, losses in performance were 6.0% for digit span, 12.1% for pattern recognition (latency), 5% for pattern memory (number correct), 6.5% for one hole, and 3% for critical tracking. The number of headaches and eye irritation also increased in a dose-response manner. The greatest effect was found for an increasing number of observations of sleep. A range of 2 to 7% decrements suggest the ACGIH TLV of 100 ppm toluene may be a good estimate of the biological threshold supporting a re-evaluation of the TLV. At 0.66 g EtOH/kg body weight symptoms and performance decrements were 6.6% for digit span, 9.2% for pattern recognition, 4.0% for continuous performance, 7.9% for symbol-digit, 16.5% for finger tapping, 6.2% for critical tracking, and 5.2% for the one hole test. The EtOH equivalents at 150 ppm toluene for digit span (0.56g EtOH/kg/body weight), the latency for pattern recognition (0.66 g EtOH kg body weight), and the one hole element "move" (0.37 g EtOH kg body weight) show that the first two measures would be affected at or above the 50 mg% blood alcohol concentration. This concentration is recognised as the lowest alcohol concentration associated with increased numbers of automobile accidents. The results suggest that EtOH may be a useful acute standard to compare the effects of various industrial solvents and support investigating an association between exposure to solvents and increased risk to safety in industry.

Adolescent↗
PubMed2005

Effects of upper airway anaesthesia on respiratory-related evoked potentials in humans.

Cortical potentials evoked by mid-inspiratory occlusion arise from numerous receptors, many of which are probably within the upper airway. Their precise nature is not known. The aim of the current study was to improve knowledge of this by studying the effects of topical upper airway anaesthesia on respiratory-related evoked potentials. Respiratory-related evoked potentials were described through the averaging of electroencephalogram (EEG) epochs following mid-inspiratory occlusions (C3-CZ; C4-CZ). A total of 21 healthy volunteers (13 male, aged 22-52 yrs) were studied during mouth breathing, before and after topical upper airway anaesthesia (lidocaine). Moreover, 15 subjects were studied during nose breathing with and without anaesthesia. Six subjects were studied whilst inhaling L-menthol. Typical potentials were present in all the subjects, their components featuring normal amplitudes and latencies. The route of breathing and upper airway anaesthesia did not modify the EEG responses to inspiratory occlusions, qualitatively or quantitatively, during mouth or nose breathing. L-menthol had no effect. Upper airway receptors sensitive to topical anaesthesia are unlikely to contribute significantly to mid-inspiratory occlusion-evoked potentials. On the contrary, deeper receptors, such as joint and muscle receptors, could contribute dominantly to these potentials.

Administration, Inhalation↗
PubMed2006

Pain during ice water test distinguishes clinical bladder hypersensitivity from overactivity disorders.

BACKGROUND: The Bladder cooling reflex (BCR) i.e. uninhibited detrusor contractions evoked by intravesical instillation of cold saline, is a segmental reflex believed to be triggered by menthol sensitive cold receptors in the bladder wall, with the afferent signals transmitted by C fibres. The BCR is a neonatal reflex that becomes suppressed by descending signals from higher centres at approximately the time when the child gains full voluntary control of voiding. It re-emerges in adults with neurogenic detrusor overactivity as a consequence of loss of central descending inhibition, resulting from conditions such as spinal cord injury or multiple sclerosis. We have recently shown an increase of nerve fibres expressing the cool and menthol receptor TRPM8 in both overactive (IDO) and painful bladder syndrome (PBS), but its functional significance is unknown. We have therefore studied the bladder cooling reflex and associated sensory symptoms in patients with PBS and overactivity disorders. METHODS: The BCR, elicited by ice water test (IWT) was performed in patients with painful bladder syndrome (PBS, n = 17), idiopathic detrusor overactivity (IDO, n = 22), neurogenic detrusor overactivity (NDO, n = 4) and stress urinary incontinence (as controls, n = 21). The IWT was performed by intravesical instillation of cold saline (0 - 4 degrees C). A positive IWT was defined as presence of uninhibited detrusor contraction evoked by cold saline, associated with urgency or with fluid expulsion. Patients were asked to report and rate any pain and cold sensation during the test. RESULTS: A positive IWT was observed in IDO (6/22, 27.3%) and NDO (4/4, 100%) patients, but was negative in all control and PBS patients. Thirteen (76.5%) PBS patients reported pain during the IWT, with significantly higher pain scores during ice water instillation compared to the baseline (P = 0.0002), or equivalent amount of bladder filling (100 mls) with saline at room temperature (P = 0.015). None of the control or overactive (NDO/IDO) patients reported any pain during the IWT. CONCLUSION: The BCR in DO may reflect loss of central inhibition, which appears necessary to elicit this reflex; the pain elicited in PBS suggests afferent sensitisation, hence sensory symptoms are evoked but not reflex detrusor contractions. The ice water test may be a useful and simple marker for clinical trials in PBS, particularly for novel selective TRPM8 antagonists.

Adult↗
PubMed2003

Iontophoretic transdermal delivery of buspirone hydrochloride in hairless mouse skin.

The transdermal delivery of buspirone hydrochloride across hairless mouse skin and the combined effect of iontophoresis and terpene enhancers were evaluated in vitro using Franz diffusion cells. Iontophoretic delivery was optimized by evaluating the effect of drug concentration, current density, and pH of the vehicle solution. Increasing the current density from 0.05 to 0.1 mA/cm2 resulted in doubling of the iontophoretic flux of buspirone hydrochloride, while increasing drug concentration from 1% to 2% had no effect on flux. Using phosphate buffer to adjust the pH of the drug solution decreased the buspirone hydrochloride iontophoretic flux relative to water solutions. Incorporating buspirone hydrochloride into ethanol:water (50:50 vol/vol) based gel formulations using carboxymethylcellulose and hydroxypropylmethylcellulose had no effect on iontophoretic delivery. Incorporation of three terpene enhancers (menthol, cineole, and terpineol) into the gel resulted in a synergistic effect when combined with iontophoresis. Menthol was the most active enhancer, and when combined with iontophoresis it was possible to deliver 10 mg/cm2/day of buspirone hydrochloride.

Administration, Cutaneous↗
PubMed2026

Deep mutational scan of the pore of the cold-sensing TRPM8 channel.

Members of the Transient Receptor Potential (TRP) family of ion channels have a nearly ubiquitous role in human physiology, tuning cell signaling to remarkably diverse physical and chemical stimuli. Although there is extensive structural data on TRP channels, a systematic and unbiased interrogation of structure-function relations in these proteins is required to fully elucidate their mechanisms of function. By focusing on a critical pore region of the TRPM8 channel, which is the main detector of cold and cooling agents in sensory neurons, we show how deep mutational scanning can be used in combination with the available structural data to understand how TRP channels respond to stimuli. We define a novel mechanism whereby the extracellular pore loop, which has only been resolved in structures representing desensitized states of the channel, plays an essential role in the response of TRPM8 to menthol or cold by coordinating the movement of the S6 helices that line and gate the pore, and the ion-selectivity filter that binds permeant cations. Moreover, our screen reveals sequence determinants along the S6 helices that explain how their architecture sustains gating and, together, provide strong support for a structural mechanism of TRPM8 pore opening in response to menthol and cold.

Journal Article↗
PubMed2001

Environment and medication use influence olfactory abilities of older adults.

BACKGROUND: Age-associated changes in eating behavior and nutritional status are often caused by changes in olfactory perception. OBJECTIVE: This study determined the relative contribution of medication use and environmental risk to age-associated change in olfaction. DESIGN: Fifty participants aged 50-96 (M = 70.4) in two groups (environmentally at-risk and low-risk) were administered a set of four olfactory tasks, WAIS Vocabulary, MMSE, and demographic questionnaires. Environmental risk was defined as having worked in places where exposure to caustic fumes (e.g., formaldehyde, toluene, etc.) was common and long-term. Olfactory tasks included detection thresholds for phenethyl alcohol (PEA; assesses olfactory function) and menthol (assesses olfactory and trigeminal function); odor recognition in a forced-choice paradigm; odor difference discrimination; and odor identification with supplied names. RESULTS: The high-risk group had significantly higher thresholds for PEA, and significant within-group variability for menthol. Medication usage and cognitive status were significantly associated with odor recognition. Only medication was strongly associated with the odor discrimination task. Medication usage, environmental risk, and age in order were found to be the greatest risk factors for odor identification. CONCLUSION: These results highlight the need to carefully consider environmental and pharmacological effects in age-associated sensory tasks.

Aged↗
PubMedDate not supplied

Smoking among Asian American and Hawaiian/Pacific Islander youth: data from the 2000 National Youth Tobacco Survey.

OBJECTIVES: One of the first steps to reducing the disproportionate burden of tobacco on racial and ethnic minorities is to understand how tobacco differentially affects these populations. This paper, based on a nationally representative sample of Asian American youth and a smaller sample of Hawaiian/Pacific Islander youth, provides the tobacco control community with important information about the smoking behavior of these youth. METHODS: The National Youth Tobacco Survey conducted during the Spring of 2000 (NYTS 2000) provides recent national estimates of smoking behavior among Asian American youth. The data also permit a limited exploration of possible differences between self-described Asians and Hawaiian/Pacific Islander youth, two groups that have been combined into a single racial/ethnic category in earlier national studies. FINDINGS: This report provides estimates and 95 percent confidence intervals for current smoking, age of smoking initiation, use of menthol cigarettes and tobacco brand preferences. CONCLUSIONS: NYTS 2000 data indicate that during the last year of high school, one third of Asian American youth are smokers. Of these youth, 60% report that their usual brand of cigarettes is a menthol brand. Among female Hawaiian/Pacific Islander youth in middle school, more than 25% report having smoked during the past month.

Adolescent↗
PubMed2003

Effect of vehicles and penetration enhancers on the in vitro percutaneous absorption of celecoxib through human skin.

The aim of this study was the comparison of three different formulations (gel, o/w emulsion, oleagenous cream) and two penetration enhancers (oleic acid and menthol) as vehicle systems for celecoxib in respect of release and penetration through excised human skin in vitro. The influence of the vehicle on the release rate was studied in vitro using a cellulose acetate membrane. The release rate could be increased by up to 6.5 and 2.5 times with gel and o/w emulsion compared to oleagenous cream respectively. Further in vitro penetration measurements using human skin on Franz diffusion cells were performed with and without oleic acid and menthol as enhancers. It was shown that the penetration rate is strongly dependent upon the enhancer type and concentration but not on the vehicle itself and could be increased by 48% when 5% oleic acid was used in oleagenous cream. In all formulations tested, celecoxib was released and penetrated into human skin more quickly and to a greater extent from the gel formulations. There is no topical formulation available of celecoxib and its penetration properties through human skin have not been investigated. Since celecoxib creates some gastrointestinal disturbances, topical formulations of celecoxib preferably in gel form including 5% oleic acid could be suggested as an alternative.

Celecoxib↗
PubMed1992

Modulation of cutaneous cold receptor function by electrolytes, hormones and thermal adaptation.

The response properties of feline cold receptors were analyzed under control conditions, during conditions of altered external calcium concentrations and during application of menthol, catecholamines and ouabain. Afferent activity was extracellularly recorded from cold fibres of an isolated preparation of the tongue. Reduced calcium levels (0.5 mM) generally enhanced and elevated calcium levels (5.0 mM) suppressed cold fibre activity. The effects of menthol (10(-5) M) on cold receptors were qualitatively similar to those of reduced calcium. Application of adrenaline and noradrenaline (10(-6) M) were predominantly inhibiting. In cold receptors, the mean discharge rate is determined by the frequency of an oscillating receptor process and the probability of each cycle of this process to initiate afferent impulses. All measures mainly affected the probability of impulse generation rather than the oscillation frequency. Application of ouabain (10(-6) M) resulted in excitatory responses, caused by an increase of both probability of impulse generation and frequency of the oscillating receptor process. It is concluded that cold receptor function is based on a specific combination of common neuronal elements rather than on specific sensory processes.

Acclimatization↗
PubMed2005

[Studies on the nasal epithelium toxicity of adjuvants and recombination hirudin (rHV2) nasal spary].

OBJECTIVE: To investigate the nasal epithelium toxicity of adjuvants and rHV2 nasal spary(HVS). METHOD: Ciliary movement were evaluated with in situ toad palate model; The histology assessment of nasal epithelium were carried out after long-lasting and repeated use of HVS. RESULT AND CONCLUSION: Adjuvants included SDS, Brij 35, azone, lecithin, EDTA, menthol, nipagin and thiomersal were able to significantly inhibited the ciliary movement, while tween80, glycyrrhizic acid monoammonium salt, benzalkonium bromide, sodium benzoate and adhensive materials investigated had less influence on it. HVS was able to damaged the nasal epithelium, but this effect recovered soon after stopping administration. It was demonstrated that SDS, Brij 35, azone,lecithin, EDTA, menthol, nipagin and thiomersal. It had significant cilitoxity, while tween80, glycyrrhizic acid monoammonium salt, benzalkonium bromide, sodium benzoate and adhensive materials investigated had no significance; Chitosan co-administration with some adjuvants may make the cillitoxity severer; It is available that rHV2 be administered by nasal spary.

Adjuvants, Pharmaceutic↗
PubMed2006

[The role of four natures of medicine in acupoint sticking therapy].

OBJECTIVE: To investigate the effect of four natures of medicine on therapeutic effect of acupoint sticking therapy. METHODS: Sixty-one cases of primary dysmenorrhea were randomly divided into a capsaicin group (n=20), a menthol group (n=20) and a control group (n=21). They were treated respectively with capsaicin and menthol, which are extracts of Lajiao (Fructus Capsici) and Bohe (Herba Menthae) with same pungent in flavor and different cold (cool) and heat in property, and application of Tongjing Jiu Tieji (plaster for dysmenorrhea) at Shenque (CV 8). Changes of clinical symptoms before and after treatment were observed. RESULTS: After treatment, the cumulative scores of symptoms and the scores of pain decreased significantly in the 3 groups (P < 0.01), with no significant differences among the 3 groups (P > 0.05). CONCLUSION: In acupoint sticking therapy, the four natures of medicine have no obvious effect on the therapeutic effect, so the four natures of medicine should not used as main standard of medicine selection.

Acupuncture Points↗
PubMed1991

[Dragées bengué with cocaine. Historic review of legislation concerning cocaine].

The Bengué sugar-coated pills with menthol and cocaine, followed by the "B.M.C. pills" (with borax, methanol and cocaine) were delivered freely at the chemist's shop. The fact that nobody seemed shocked by the free delivery of this dope does not result only from the circumstance that it was allowed by law, but also because, in our countries, in the XIXth century, there were as good as no cases of cocaine mania. Owing to personal experiments, it became known in wide social circles that cocaine was not only an anesthetic and pain-killing remedy, but also an intoxicating drug that can quickly lead to addiction. Physicians began to search for means of eliminating the plague of addiction: a first International Opium-meeting was held in Shanghai in 1909. After that time, international meetings were held in The Hague (1912) and Geneva (1924 and 1925). Strangely enough, we find that in the promulgated laws an exception is made for pharmaceutical products which contain less than 0.2% morphine or less than 0.1% cocaine. When the medical world began to devote more attention to the danger of cocaine mania, the pharmaceutical and the chemical world became alarmed. A synthetic substitute was searched for and found; it should be less toxic and less addicting. The producers of the BMC pills eagerly adopted the new drugs. They replaced cocaine by amylocaine. The name of the pills was changed into BMA pills (borax-menthol-amylocaine). The coat of the pills remained the same and not one single patient ever noticed the substitution!

Belgium↗
PubMed1987

Capsaicin and its effects on olfaction and trigeminal chemoreception.

Capsaicin injections severely reduced or eliminated nasal trigeminal responses to 3 odorants (Experiment 1). However, capsaicin treated animals exhibited no deficits in locating buried food, in odor avoidance learning, or in operant odor detection and discrimination (Experiments 2 and 3). In addition, capsaicin desensitization did not affect responsiveness to salty or sour, but may have raised rejection thresholds for bitter (Experiment 4). Finally, while desensitized animals rejected menthol solution, they consumed relatively more than controls, suggesting that capsaicin may have menthol sensitivity. The present results suggest that substance P-containing fibers mediate trigeminal responsiveness to odorants and irritants but that the loss of this responsiveness does not appreciably affect smell or taste, per se.

Animals↗