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Abstract: The antiviral neuraminidase inhibitor oseltamivir (OSV) is widely used to suppress viral replication in the treatment of influenza. Here, we report that OSV administration significantly suppressed respiratory mucosal secretory IgA responses with respect to antigen (Ag)-specific antibody (Ab) production and also the induction of Ag-specific IgA Ab-forming cells, but not systemic IgG responses, in weanling mice as a model of pediatric influenza. Neutralizing activities of the airway fluids in oral OSV-treated mice were significantly less than those of sham-treated mice. Our findings suggest the risk of re-infection in patients showing a low mucosal response following OSV treatment. [Copyright &y& Elsevier]

Aromatherapy and plant-based essential oils are widely used as complementary and alternative therapies for symptoms including anxiety. Furthermore, it was reportedly effective for the care of several diseases such as Alzheimer's disease and depressive illness. To investigate the pharmacological effects of essential oils, we developed an in vitro assay system using immortalized hypothalamic neuronal cells (GT1-7 cells). In this study, we evaluated the effects of essential oils on neuronal death induced by hydrogen peroxide (H2O2), aluminum, zinc, or the antagonist of estrogen receptor (tamoxifen). Among tests of various essential oils, we found that H2O2-induced neuronal death was attenuated by the essential oils of damask rose, eucalyptus, fennel, geranium, ginger, kabosu, mandarin, myrrh, and neroli. Damask rose oil had protective effects against aluminum-induced neurotoxicity, while geranium and rosemary oil showed protective activity against zinc-induced neurotoxicity. In contrast, geranium oil and ginger oil enhanced the neurotoxicity of tamoxifen. Our in vitro assay system could be useful for the neuropharmacological and endocrine pharmacological studies of essential oils.

Trace elements including iron, zinc, copper, and manganese play essential roles in the maintenance of brain functions. Accumulating evidence suggests that dyshomeostasis of trace elements is implicated in the pathogenesis of neurodegenerative diseases including Alzheimer's disease, vascular type of dementia, prion diseases, and dementia with Lewy bodies. These diseases share similarity in the formation of β-sheets containing amyloid fibrils from disease-associated proteins, including the β-amyloid protein (AβP), the prion protein, α-synuclein, and polyglutamine, and the introduction of apoptotic degeneration. Trace elements can bind to these proteins and cause their conformational changes. Furthermore, these proteins reportedly play crucial roles in the regulation of trace elements. Considering that these proteins colocalize in synapses, it is possible that the interactions between the disease-associated proteins and trace elements are based on the physiological roles of these proteins. We review here the current understanding of the pathology of neurodegenerative diseases based on metal binding to disease-associated proteins and on the disruption of metal homeostasis.

The nasal route for vaccination offers both mucosal and systemic immunity for the prophylaxis of respiratory diseases. In order to induce maximal protective mucosal immunity, co-administration of mucosal adjuvant is essential. In the present review, we discuss natural pulmonary surfactant and its synthetic compound as safe and effective mucosal adjuvants, particularly for the children. The intranasal administration of influenza hemagglutinin(HA) vaccine with the natural compound or its mimicking synthetic compound induced both anti-HA sIgA and IgG in the airway and in the serum, the efficacy being almost equivalent to cholera toxin. No inflammatory cytokine induction and no inflammatory cell migration were detected in nasal cavity. These data suggest that pulmonary surfactant and its synthetic compound are safe and effective mucosal adjuvants that enhance the protective immunity without incurring a risk of inflammation.