## 3 Results  
LE Significantly Ameliorated Nasal Allergy Symptoms and Reduced NALFcytokine Levels in Mice with OVA-Induced AR  
Chronic inflammation, itchy nose, sneezing, and rhinorrhea are common symptoms of AR [13]. To evaluate the effectiveness of LE treatment on AR symptoms, we examined the frequency of rubbing and sneezing over a period of 10 min on the final day of intranasal OVA administration. The frequency of rubbing and sneezing was significantly higher in OVA-induced AR mice than in control mice. However, compared with the OVA group, the LE (50 or 100 mg/kg) group showed significantly fewer allergic nasal symptoms. CIC,an intranasal corticoid approved for the treatment of AR [14; 15], was used as a positive control; this also reduced allergy symptoms significantly in the OVA model (Figure 1B,C). Next, we examined cytokine levels in NALF samples from OVA-induced AR mice. IL-4 levels in NALF from the OVA group were higher than those in the control group, whereas those in the LE treatment group were lower, albeit not significantly (Figure 1D). Levels of IL-5 and IL-13 in the NALF from the OVA group were significantly higher than those in the control group (Figure 1D-F). However, when compared with OVA, LE (100 mg/kg) and CIC significantly reduced the levels of IL-5 and IL-13 in NALF. These results indicate that LE ameliorates allergic responses in AR mice by suppressing production of cytokines. LE Significantly Reduced Nasal Mucosal Thickness and the Accumulation of Eosinophils, Goblet Cells, and Mast Cells in OVA-Induced AR Mice Nasal Tissues  
Using H&E staining, the effects of LE on the nasal mucosa were then evaluated. The nasal mucosa of OVA-induced AR mice exhibited epithelial disruption, inflammatory cell infiltration, and mucosal detachment, whereas the nasal mucosa of LE-treated mice (50 mg/kg and 100 mg/kg) was protected from OVA-induced damage, as observed by measuring the nasal epithelium thickness (Figure 2A,B). Furthermore, LE suppressed OVA-induced swelling of epithelial cells. Eosinophils, crucial effector cells during allergic inflammation, have been linked to development of allergic illnesses such as asthma and rhinitis [16]. Therefore, we asked whether LE prevents eosinophil infiltration in the nasal mucosa. Significantly greater eosinophil infiltration was observed in the OVA group compared to the control group. However, the LE group displayed considerably less eosinophil infiltration than the OVA group (Figure 2C). PAS staining revealed a significant increase in goblet cell hyperplasia in the OVA group, which was significantly reduced by oral administration of LE (Figure 2A,D). To count mast cells, the nasal mucosa was then stained with toluidine blue. In the OVA group, there were significantly more mast cells than in the control group. In contrast, LE decreased nasal mast cell infiltration, indicating that LE treatment inhibits mast cell infiltration into the nasal mucosa of AR mice (Figure 2A,E). LE Significantly Suppressed Allergic Responses by Modulating OVA-Specific Immunoglobulins in the Serum of OVA-Induced AR Mice  
When exposed to allergens, IgE-primed mast cells degranulate and release a large quantity of histamine, resulting in a rapid and strong allergic response. Repeated exposure to an allergen induces production of additional IgE and IgG1, which enhances immune responses. Th1 cells, which can regulate IgE and IgG1 activity, induce immunoglobulin class switching by B cells, leading to the production of IgG2a [17; 18]. Therefore, we used an ELISA to measure the quantity of OVA-specific immunoglobulins in serum. The results show that levels of OVA-specific IgE and IgG1 were considerably greater in the OVA group, but levels of OVA-specific IgG2a in the OVA group tended to be lower than in the control group. However, the amount of OVA-specific IgE in serum fell significantly after administration of 50 mg/kg or 100 mg/kg LE (Figure 3A). At a dose of 100 mg/kg, LE significantly decreased the amount of OVA-specific IgG1 (Figure 3B).