Effects of rosmarinic acid on the inflammatory response in allergic rhinitis rat models after PM2.5 exposure

Abstract

Background Studies have shown the promising prospects of rosmarinic acid (RosA) for the prevention and treatment of allergic diseases. Objective The aim of this study was to investigate the effects of RosA on inflammatory reaction in rat models of allergic rhinitis (AR) after PM2.5 exposure. Methods Allergic rhinitis rat models were established by ovalbumin sensitization, and PM2.5 was applied at a concentration of 1000 μg/m3, 3 h a day for 30 consecutive days. RosA was administered via intraperitoneal injection (20 mg/kg/d) for seven consecutive days. Allergic nasal symptoms were recorded. The expressions of interleukin (IL)‐4, IL‐13, interferon (INF)‐γ, and OVA‐sIgE were determined by ELISA. Histopathological changes in nasal mucosa were observed by HE staining. mRNA expressions of T‐bet and GATA‐3 in nasal mucosa were detected by RT‐PCR. NF‐κBp65 in cell nuclei and IκBα in cytoplasm were analyzed by Western blot. Results PM2.5 exposure worsened allergic nasal symptoms in AR rats, while RosA ameliorated these symptoms. Histopathologically, AR rats exhibited disorganized nasal mucosal epithelium, cell exfoliation, eosinophilic infiltration of lamina propria, gland swelling, and submucosal vascular congestion, which were aggravated by PM2.5 exposure and alleviated by RosA. RosA decreased the expressions of IL‐4, IL‐13, and increased the level of IFN‐γ in PM2.5‐exposed AR rats. After RosA intervention, the expressions of GATA‐3 mRNA and NF‐κBp65 in PM2.5‐exposed AR rats were significantly reduced, while those of T‐bet mRNA and IκBα were markedly increased. Conclusion Rosmarinic acid may alleviate symptoms of AR rat models exposed to PM2.5 through the modulation of the NF‐κB pathway and Th1/Th2 balance.

Effects of rosmarinic acid on immune response and intestinal microbiota in ovalbumin‐induced intestinal allergy mice

“…36,37 RA has been widely reported to relieve allergic symptoms through regulating the balance of Th1/Th2 cytokines in atopic dermatitis, allergic rhinitis, asthma and so forth. 19,38 Interestingly, the expressions of IL-4 and IL-5 were markedly upregulated in the mice of the model group, but significantly decreased by oral administration of RA (Fig. 5).…”

“…15,16 For anti-anaphylaxis, RA has been widely reported to exert protective effects on atopic dermatitis, asthma and allergic rhinitis. [17][18][19] Moreover, RA has also been extensively studied for clinical application in inflamed colon, diabetes and even cancers. [20][21][22] However, little is known about the role of RA in regulating the immune response and the intestinal flora to prevent intestinal food allergy.…”

“…Rosmarinic acid (RA), an active polyphenol found in many edible medicinal herbs, has been reported to possess a broad range of pharmacological activities, like anti‐inflammatory, cardioprotective and anti‐allergic activities 15,16 . For anti‐anaphylaxis, RA has been widely reported to exert protective effects on atopic dermatitis, asthma and allergic rhinitis 17‐19 . Moreover, RA has also been extensively studied for clinical application in inflamed colon, diabetes and even cancers 20‐22 .…”

Hepatoprotective Effects of Rosmarinic Acid on Ovalbumin-Induced Intestinal Food Allergy Mouse Model

“…The immunomodulatory impacts of RA also make it a novel potential agent for the treatment of immune disorders of the body [ 23 ]. In allergic rhinitis, dermatitis, and asthma, RA showed obvious beneficial effects in alleviating allergic reactions such as mild anaphylactic symptoms, reduction in specific IgE and immune-mediators, and relieved tissue damage [ 24 , 25 , 26 ]. In this study, RA intervention at 30, 90, and 270 mg/kg significantly inhibited the OVA challenge-induced diarrheal, anaphylactic symptoms, and hypothermia ( Figure 1 B,C).…”

A Combined NMR and UV–Vis Approach to Evaluate Radical Scavenging Activity of Rosmarinic Acid and Other Polyphenols

“…RA belongs to the group of hydroxycinnamic acids (HCA), and its chemical structure consists of two moieties: the ester of caffeic acid and 3,4-dihydroxyphenyllactic acid ( Figure 1 ). RA has shown remarkable antioxidant properties in vitro and in vivo [ 25 , 26 , 27 ], and its effectiveness in neutralizing free radicals has been widely documented [ 28 , 29 , 30 , 31 ]. Its important ability to capture free radicals is attributed to the presence of hydroxyl groups in the phenolic rings, which allows it to donate and accept electrons, thus stabilizing radical species and preventing cell damage.…”