The protective effect of Naringenin against ovalbumin-induced allergic rhinitis in rats.

BACKGROUND Allergic rhinitis (AR) is a ubiquitous chronic disease with a growing incidence. We aimed to investigate the protective effect of naringenin against AR induced in rats. METHODS Thirty-two Sprague Dawley rats were divided into four groups of eight animals each. Group 1 represented the control group. The other 24 rats were sensitized with intraperitoneal 0.3 mg ovalbumin (OVA) and 30 mg aluminum hydroxide every other day for 14 days to induce AR. Ten microliters OVA was administered to both nostrils by inhalation for the following seven days to provoke AR. Group 2 represented the AR group and received no treatment. Group 3 was treated as the reference group and received 5 mg/kg desloratadine every day between days 15 and 21. Group 4 received 100 mg/kg naringenin orally between days 15 and 21. All animal's sneezing and nasal itching scores were recorded on day 22. The rats were then sacrificed. Serum total IgE, IL4 and IL5 values were studied, and nasal structures were extracted 'en bloc' for histopathological examination. RESULTS Significant clinical recovery was achieved in the group treated with naringenin. Serum total IgE, IL4 and IL5 values in the naringenin group were significantly lower than in the AR group, and significant histopathological improvement was observed compared to the AR group. CONCLUSIONS Naringenin produced significant clinical, biochemical and histopathological benefits in rats with induced AR. These effects suggest that naringenin is a promising agent for the treatment of AR.