Intranasal application of glucocorticoid alleviates olfactory dysfunction in mice with allergic rhinitis

Association between Administration of Systemic Corticosteroids and the Recovery of Olfactory and/or Gustatory Functions in Patients with COVID-19: A Prospective Cohort Study

AIM: This study is a prospective cohort study aimed to assess the effect of systemic corticosteroids administration time in the recovery of gustatory and olfactory sensations dysfunction (ageusia and anosmia) in COVID-19 patients. MATERIALS AND METHODS: Sixty-seven COVID-19 patients with symptoms of ageusia and anosmia were recruited (that their COVID infection was confirmed using polymerase chain reaction). Daily 10 mg of systemic corticosteroids were prescribed in the 1st week and then reduced to 5 mg in the 2nd week to all the patients to observe taste and smell sensation recovery. All data were recorded and then analyzed. Patients were then grouped into two groups (early and late groups) according to the duration of their taste and smell dysfunction. RESULTS: Regression analysis showed that early corticosteroid administration resulted in a significant decrease in recovery time of ageusia and anosmia (0.27 [0.2–0.35], p < 0.001). Patients in the early administration group (<1 week) showed faster improvement in regaining taste and smell functions than in the late administration group (>1 week) with significant difference (p < 0.001). CONCLUSIONS: The use of systemic corticosteroids in early phases of covid-19 infection help in faster recovery of ageusia and anosmia.

Activation of Dopamine D2 Receptor Alleviates Neuroinflammation in a Mouse Model of Allergic Rhinitis With Olfactory Dysfunction

PURPOSE

Allergic rhinitis (AR) is a common otolaryngology disease and one of the clinical causes of olfactory dysfunction (OD). The olfactory bulb serves as a transfer station for olfactory information transmission, and alleviating its neuroinflammation may be expected to improve AR-induced OD. Recent studies have suggested that the dopamine D2 receptor acts as a key target in regulating immune functions and neuroinflammatory reaction. However, the effect of dopamine D2 receptor on AR-induced neuroinflammation is still unknown.

METHODS

An AR mouse model with OD induced by ovalbumin were constructed. The buried food pellet test was to evaluate the olfactory function of the mice. Immunofluorescence staining, hematoxylin and eosin staining, enzyme-linked immunosorbent assay and western blotting were also used to investigate the molecular mechanisms underlying the anti-inflammatory effects of the dopamine D2 receptor in AR-induced OD.

RESULTS

We found that AR-induced OD has a relationship with inflammatory responses in the olfactory bulb. Nasal administration of quinpirole (Quin, a dopamine D2 receptor agonist, 3 mg/kg) improved olfactory function in mice, inhibited the expression of toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signalings and the levels of tumor necrosis factor-α, interleukin (IL)-1β and IL-6 in the olfactory bulb. In vitro, Quin (20 μmol/L) inhibited the release of TLR4/NF-κB signalings-dependent inflammatory cytokines in cultured microglia.

CONCLUSIONS

Activation of the dopamine D2 receptor inhibits the release of inflammatory cytokines through TLR4/NF-κB signaling in the olfactory bulb microglia, and protects olfactory function.

Turkish Guideline for Diagnosis and Treatment of Allergic Rhinitis (ART)

OBJECT

To prepare a national guideline for Otorhinolaryngologist who treat allergic rhinitis patients.

METHODS

The study was conducted by three authors, namely the writing support team. The support team made the study plan, determined the writing instructions, chose the subgroups including the advisory committee, the advisors for authors and the authors. A workshop was organized at the very beginning to explain the details of the study to the team. Advisors took the chance to meet their coworkers in their subgroups and determined the main headings and subheadings of the guideline, together with the authors. After key words were determined by the authors, literature search was done in various databases. The authors keep in touch with the advisors and the advisors with the advisory committee and the support group at every stage of the study. National and International published articles as well as the abstracts of unpublished studies, imperatively presented in National Congresses, were included in this guideline. Only Guideline and meta-analyses published in last seven years (2013-2017) and randomized controlled studies published in last two years (2015-2017) were included. After all work was completed by the subgroups, support team brought all work together and edited the article.

RESULTS

A detailed guideline about all aspects of allergic rhinitis was created.

CONCLUSION

The authors believe that this guideline will enable a compact and up-to-date information on allergic rhinitis to healthcare professionals. This guideline is the first in the field of Otolaryngology in Turkey. It should be updated at regular intervals.

Shufengjiedu capsules protect against neuronal loss in olfactory epithelium and lung injury by enhancing autophagy in rats with allergic rhinitis

Shufengjiedu capsules (SFJDCs), a traditional Chinese medicine, have been widely used as an antiviral, antibacterial, antitumor, and anti-inflammatory drug. However, the roles of SFJDCs in allergic rhinitis remain unclear. The purpose of this study was to investigate the effects of SFJDCs in olfaction and lung injury in rats with allergic rhinitis. An animal model of allergic rhinitis was created by intraperitoneal injection and intranasal administration of ovalbumin to rats. All rats were divided into seven groups: a model group, a low-dose SFJDC group, a medium-dose SFJDC group, a high-dose SFJDC group, a cetirizine group, and a control group. Hematoxylin and eosin (HE) staining was used to observe pathological changes in rat lung and olfactory epithelium (OE) tissue, and peripheral blood was collected and subjected to an enzyme-linked immunosorbent assay (ELISA) to detect IgE, tumor necrosis factor alpha (TNF-α), and IL-1ꞵ levels. Western blotting, immunohistochemistry staining, and immunofluorescence staining were performed to detect inflammatory cytokines and levels of the autophagy biomarker beclin1 and the apoptosis biomarker cleaeved-caspased3 in lung and OE tissue. ELISA indicated that SFJDCs significantly decreased IgE, TNF-α, and IL-1ꞵ levels in peripheral blood, the lungs, and OE tissue. In addition, Western blotting and staining indicated that SFJDCs repair lung injury, protect against neuronal apoptosis in OE, and rescue impaired autophagy in the lungs and OE tissue. In conclusion, results indicated that SFJDCs might protect against neuronal loss in the OE and lung injury by enhancing autophagy and decreasing apoptosis in rats with allergic rhinitis. Therefore, SFJDCs might serve as an alternative treatment for allergic rhinitis.

Using high-throughput metabolomics to discover perturbed metabolic pathways and biomarkers of allergic rhinitis as potential targets to reveal the effects and mechanism of geniposide

In this study, we probed the molecular mechanisms of metabolic biomarkers and pathways affected by the bioactive ingredient geniposide (GP), which was shown to protect against experimental allergic rhinitis in mice. The methods used here involved a metabolomics strategy based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-TOF/MS). Using the metabolomics strategy, serum samples of mice in control, model and GP groups were used to explore the differential production of metabolites and pathways related to defense activity of GP towards allergic rhinitis. Allergic symptom, inflammatory factors, and cell populations in the mice spleens were reversed by GP treatment. Seventeen potential biomarkers were discovered in experimental allergic rhinitis mice. GP was shown to have a regulatory effect on 12 of them, which were associated with 8 key metabolic pathways. The ingenuity pathway analysis platform was used to further understand the relationship between metabolic changes and pharmacological activity of GP. The pathways which affected by GP involved cellular growth and proliferation, organismal development, and free radical scavenging. This metabolomics study produced valuable information about potential biomarkers and pathways affected by GP during its effective prevention and therapeutic targeting of allergic rhinitis.

In this study, we probed the molecular mechanisms of metabolic biomarkers and pathways affected by the bioactive ingredient geniposide (GP), which was shown to protect against experimental allergic rhinitis in mice.

Factors that modulate olfactory dysfunction

The olfactory system is one of a few areas in the nervous system which is capable of regeneration throughout the life. Olfactory sensory neurons reside in the nasal cavity are continuously replenished with new neurons arising from stem cells. Some factors such as aging, neurodegenerative diseases, head trauma, brain tumor extraction and infection cause olfactory dysfunction which significantly influences physical wellbeing, quality of life, mental health, nutritional status, memory processes, identifying danger and is associated with increased mortality. Therefore, finding a treatment to improve olfactory dysfunction is needed. Recent research efforts in the field have shown some very promising new approaches to treat olfactory dysfunction. This review explores the current studies that have addressed therapeutic approaches to improve olfactory neuron regeneration based on cell transplantation therapy, modulation of physiological olfactory dysfunction and drug treatments.