Effectiveness of quercetin in an experimental rat model of allergic rhinitis

Abstract

We aimed to investigate whether quercetin had a therapeutic effect in an experimental rat model of allergic rhinitis. The study was conducted with 35 rats, which were randomly assigned into 4 groups: group 1 (n = 5), sham group; group 2 (quercetin group, n = 10) received 80 mg/kg day quercetin; group 3 (steroid group, n = 10) received steroid (mometasone furoate); and group 4 (control group, n = 10), received ovalbumin alone. Rats were sensitized by administration of ovalbumin on alternate days over 14 days via an intraperitoneal route. On day 15, in addition to ovalbumin via an intranasal route, quercetin and steroid were given over 7 days to the corresponding groups. All rats were then sacrificed and nasal turbinates were evaluated histopathologically, and serum total IgE and ovalbumin (OVA)-specific IgE values were measured before and after treatment. A significant increase in OVA-specific IgE values was detected in all groups except sham group. A significant increase was detected in post-treatment total IgE levels in the control group, while no significant change was detected in the sham, quercetin, and intranasal steroid groups. On histopathological evaluation, it was observed that findings of allergic rhinitis were suppressed in the quercetin group when compared to the control group. In immunohistochemical evaluation, it was detected that COX-2 and VIP expressions were weaker in the quercetin group compared to the control group. Based on these findings, we conclude that quercetin was effective in allergic rhinitis induced by ovalbumin in rats both histopathologically and serologically.

Testing of natural products in clinical trials targeting the SARS-CoV-2 (Covid-19) viral spike protein-angiotensin converting enzyme-2 (ACE2) interaction

“…The United States Food and Drug Administration has already approved oral doses of quercetin as safe for human consumption. Quercetin given nasally was effective in a rat model of allergic rhinitis [12], and the safety of quercetin has been favourably assessed [13]. Quercetin at high doses, like any other bioactive compound, could have potentially off-target effects.…”

Exploring Pharmacological Mechanisms of Xiang Ju Tablets in the Treatment of Allergic Rhinitis via a Network Pharmacology Approach

“…In previous studies, quercetin has been found to inhibit mast cell activation, inflammatory cytokine production, and histamine release after immunological stimulation. Quercetin may suppress AR in rats by increasing Cl transport and ciliary beat frequency [41]. Quercetin modulates the activation of inflammatory cells and neuropeptide production and results in improvement of clinical conditions of allergic diseases, especially AR [42].…”

Quercetin with the potential effect on allergic diseases

“…In immune histochemical evaluation, it was detected that COX-2 and vasoactive intestinal polypeptide (VIP) expressions were weaker in the quercetin group than the control group. According to these findings, they concluded that quercetin was effective in AR-induced by OVA in rats both histopathologically and serologically [45] (Table 2).…”