Anosmia does not impair the anxiolytic-like effect of lavender essential oil inhalation in mice.

AIM: The inhalation of Lavandula angustifolia (lavender) essential oil has anxiolytic-like effects in animal models and humans, but its mechanism of action is still not fully understood. The inhalation of essential oils can induce anxiolytic effects through the central nervous system (e.g., lung absorption and bloodstream transport) or stimulation of the olfactory system and secondary activation of brain regions. Thus, the main objective of the present study was to evaluate whether the perception of lavender essential oil aroma, when inhaled, is necessary to obtain its anxiolytic-like effects in mice tested in the marble-burying test. MAIN METHODS: Anosmia was induced by irrigating the nasal cavity with zinc gluconate+zinc acetate so that the mice could not detect odors in the olfactory discrimination test. The marble-burying test was used to evaluate the anxiolytic-like effects of inhaled lavender essential oil. KEY FINDINGS: Anosmia did not interfere with the anxiolytic-like effect of lavender essential oil inhalation in the marble-burying test at concentrations of 2.5% (number of marbles buried: vehicle, 4.7±1.0; zinc, 6.2±2.2; p>0.10) and 5% (number of marbles buried: vehicle, 3.4±0.8; zinc, 4.3±0.9; p>0.10). Lavender essential oil at a concentration of 0.5% was ineffective. SIGNIFICANCE: These results suggest that olfactory system activation is unlikely to participate in the anxiolytic-like effect of lavender essential oil inhalation.

Anxiolytic-like effect of lavender essential oil inhalation in mice: participation of serotonergic but not GABAA/benzodiazepine neurotransmission.

ETHNOPHARMACOLOGICAL RELEVANCE: Lavandula angustifolia (lavender) inhalation has been used in folk medicine for the treatment of anxiety, and clinical and animal studies have corroborated its anxiolytic effect, although its mechanism of action is still not fully understood. AIMS OF THE STUDY: The objective of the present study was to determine whether the GABAA/benzodiazepine complex or serotonin neurotransmission mediates the anxiolytic-like effect of lavender essential oil. MATERIALS AND METHODS: Male Swiss mice were subjected to the marble-burying test after being exposed to the aroma of lavender essential oil (1-5%), amyl acetate (5%; used as a behaviorally neutral odor), or distilled water for 15 min via inhalation. Additionally, the effect of 5% lavender essential oil was also evaluated in mice subjected to the elevated plus maze. GABAA/benzodiazepine mediation was evaluated by pretreating the mice with the GABAA receptor antagonist picrotoxin before the marble burying test and [(3)H]flunitrazepam binding to the benzodiazepine site on the GABAA receptor. Serotonergic mediation was studied by pretreating the mice with O-methyl-[3H]-N-(2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl)-N-(2-pyridinyl) cyclohexanecarboxamide trihydrochloride (WAY100635), a serotonin 5-HT1A receptor antagonist before the marble burying test. We also evaluated changes in the pharmacologically induced serotonin syndrome and the effects of combined administration of subeffective doses of lavender essential oil and the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). RESULTS: Lavender essential oil (1-5%) decreased the number of marbles buried compared with the control and amyl acetate groups. In the elevated plus maze, 5% lavender essential oil inhalation increased the percentage of time spent on and number of entries into the open arms compared with controls. No effect was seen in the number of closed arm entries or number of beam interruptions in the automated activity chamber. Pretreatment with the GABAA receptor antagonist picrotoxin (0.5mg/kg) did not modify the behavioral effect of 5% lavender essential oil in the marble-burying test. Lavender essential oil also did not alter [(3)H]flunitrazepam binding to the benzodiazepine site on the GABAA receptor. Pretreatment with the serotonin 5-HT1A receptor antagonist WAY100635 (3mg/kg) blocked the anxiolytic-like effect of lavender essential oil and the 5-HT1A receptor agonist 8-OH-DPAT (3mg/kg). A combination of ineffective doses of 8-OH-DPAT (0.5mg/kg) and lavender essential oil (0.1%) reduced the number of marbles buried. Finally, 5% lavender essential oil attenuated the serotonin syndrome induced by 40 mg/kg fluoxetine plus 80 mg/kg 5-hydroxytryptophan. CONCLUSIONS: These results indicate an important role for the serotonergic system in the anxiolytic-like effect of lavender essential oil.

Memory impairment induced by sodium fluoride is associated with changes in brain monoamine levels.

Previous studies suggest that sodium fluoride (NaF) can impair performance in some memory tasks, such as open-field habituation and two-way active avoidance. In the present study, we evaluated the effect of NaF intake (100 ppm in drinking water for 30 days) and its short-term (15 days) withdrawal on open-field habituation and brain monoamine level. Adult male rats were allocated to three groups: tap water (NaF 1.54 ppm) for 45 days (control group); 15 days of tap water followed by NaF for 30 days; and NaF for 30 days followed by 15 days of tap water. The results showed that NaF impairs open-field habituation and increases noradrenaline (NA) and serotonin (5-HT) in the striatum, hippocampus and neocortex. Dopamine (DA) increase was restricted to the striatum. Short-term NaF withdrawal did not reverse these NaF-induced changes, and both NaF treatments led to a mild fluorosis in rat incisors. No treatment effect was seen in body weight or fluid/water consumption. These results indicate that sodium fluoride induces memory impairment that outlasts short-term NaF withdrawal (2 weeks) and may be associated with NA and 5-HT increases in discrete brain regions.

Multiple taurodontism: the challenge of endodontic treatment.

This article describe a rare case of multiple taurodontism involving all molars in a 17-year-old male. Volumetric cone-beam computed tomography was used to investigate internal and external root morphology, including that of a maxillary first molar which required endodontic treatment and retreatment. Medical history was not contributory; however, Klinefelter syndrome was the diagnostic hypothesis in this case.

Severe early childhood caries: an integral approach.

OBJECTIVE: To provide information with the purpose of helping pediatricians to recognize the risk factors for the onset of severe early childhood caries, allowing for early intervention and thus avoiding this preventable disease and its consequences. SOURCES: Information was collected from scientific articles published on the databases SciELO, MEDLINE and PUBMED in last 25 years, as well as technical books and guidelines of international committees. The keywords used were: early childhood caries, severe early childhood caries, dental caries, and children. SUMMARY OF THE FINDINGS: Severe early childhood caries affects infants and children. It is infectious, has a multifactor etiology and fast development, starting soon after dental eruption. Due to the presence of local sociocultural risk factors, it must be regarded as a symptom of alteration in the child's health and lack of adequate care. Its manifestations include pain, abscesses and chewing difficulty, affecting the child's feeding and sleep. Furthermore, it also affects the child's general health, speech, and self-esteem. CONCLUSIONS: Preventive methods to avoid severe early childhood caries have been developed and they should be used as early as possible by means of prevention programs carried out in the community and with families. Professionals responsible for providing care to babies and children should be aware of cases at risk for caries and interfere in order to improve their patients' health.

Cárie precoce e severa na infância: uma abordagem integral: [revisão] / Severe early childhood caries: an integral approach: [review]

OBJETIVO: Fornecer informações para auxiliar o médico pediatra a reconhecer os fatores de risco para o início da cárie precoce na infância e da cárie severa na infância (CSI), possibilitando a intervenção precoce de tais fatores, e, assim, evitar a instalação dessa doença prevenível e as suas consequências. FONTES DOS DADOS: As informações foram coletadas a partir de artigos científicos publicados nas bases de dados SciELO, MEDLINE e PUBMED nos últimos 25 anos, livros técnicos e publicações de consenso de organismos internacionais. As palavras-chave utilizadas foram: early childhood caries, severe early childhood caries, dental caries e children. SÍNTESE DOS DADOS: A CSI é uma forma de cárie dentária que afeta bebês e crianças. É infecciosa, de etiologia multifatorial e de desenvolvimento rápido, iniciando logo após a erupção dos dentes. Por apresentar fatores de risco local e sociocultural, deve ser considerada como sintoma de uma alteração na criança e de falta de cuidados adequados. Suas manifestações incluem dor, abscessos e dificuldades mastigatórias, afetando a alimentação e o sono da criança. Além disso, afeta também sua saúde geral, fala e autoestima. CONCLUSÕES: A CSI é uma doença com métodos preventivos estabelecidos, que devem ser introduzidos o mais precocemente possível, por meio de programas preventivos na comunidade e no núcleo familiar. Os profissionais que atendem bebês e crianças devem estar atentos aos casos com risco para o desenvolvimento da doença cárie e interceder a fim de se obter saúde.

OBJECTIVE: To provide information with the purpose of helping pediatricians to recognize the risk factors for the onset of severe early childhood caries, allowing for early intervention and thus avoiding this preventable disease and its consequences. SOURCES: Information was collected from scientific articles published on the databases SciELO, MEDLINE and PUBMED in last 25 years, as well as technical books and guidelines of international committees. The keywords used were: early childhood caries, severe early childhood caries, dental caries, and children. SUMMARY OF THE FINDINGS: Severe early childhood caries affects infants and children. It is infectious, has a multifactor etiology and fast development, starting soon after dental eruption. Due to the presence of local sociocultural risk factors, it must be regarded as a symptom of alteration in the child's health and lack of adequate care. Its manifestations include pain, abscesses and chewing difficulty, affecting the child's feeding and sleep. Furthermore, it also affects the child's general health, speech, and self-esteem. CONCLUSIONS: Preventive methods to avoid severe early childhood caries have been developed and they should be used as early as possible by means of prevention programs carried out in the community and with families. Professionals responsible for providing care to babies and children should be aware of cases at risk for caries and interfere in order to improve their patients' health.

Subchronic fluoride intake induces impairment in habituation and active avoidance tasks in rats.

Since clinical case reports suggest that sodium fluoride (NaF) intoxication may impair learning and memory, the objective of the present study was to evaluate the effects of NaF on two memory tasks: open-field habituation and two-way active avoidance. Adult male rats were exposed to NaF in drinking water at three concentrations for 30 days: 1.54 (control, tap water), 50 and 100 ppm NaF (corresponding to an intake of 0.10+/-0.005, 5.15+/-0.14, and 10.77+/-0.39 mg/kg of NaF, respectively). At day 30, the rats were placed in an open-field and retested after 24 h (test session) to measure habituation. In the two-way active avoidance task, another three groups of rats were trained in a 30-trial training session and tested again 24 h later (test session). Dental fluorosis was also evaluated. Habituation was impaired by 50 and 100 ppm, but not by 1.54 ppm NaF. Moreover, 100 ppm NaF reduced the number of avoidance responses in the active avoidance task. No locomotor impairment was observed. Mild dental fluorosis in rat incisor teeth was found in the 50 and 100 ppm NaF groups. Overall, these results suggest that moderate intoxication with sodium fluoride has potentially deleterious effects on learning and memory.