Immune-modulatory effects of bu-zhong-yi-qi-tang in ovalbumin-induced murine model of allergic asthma.
Bu-zhong-yi-qi-tang (BZYQT), an herbal formula of traditional Chinese medicine, has been an effective regimen of allergic diseases for nearly 800 years. Our previous report has demonstrated its anti-inflammatory effects in patients with perennial allergic rhinitis, and the aim of this study is to investigate the anti-asthmatic effect of BZYQT.
Female BALB/cByJNarl mice were sensitized with normal saline (control group) or OVA. Mice sensitized by OVA were fed with distilled water (OVA group), oral 0.5 g/Kg (low-dose group) or 1 g/Kg (high-dose group) of BZYQT solution once daily on days 36-40 besides their routine diet. Airway hyper-responsiveness (AHR), eosinophil infiltration, levels of cytokines and total immunoglobulin E (IgE) in broncho-alveolar lavage fluid (BALF) were determined. The lungs and tracheas were removed, and histopathologic examination was subsequently performed.
AHR was significantly reduced in both low- and high-dose BZYQT groups compared with the OVA group after inhalation of the highest dose of methacholine (50 mg/ml). The levels of eotaxin, Th2-related cytokines (IL-4, IL-5, IL-13), IgE, and eosinophil infiltration in BALF were significantly decreased in both BZYQT groups compared with the OVA group. Histopathologic examination revealed that eosinophil infiltration of the lung and trachea tissues was remarkably attenuated in both BZYQT groups.
Oral administration of BZYQT solution may exert anti-asthmatic effect by relieving AHR in OVA-sensitized mice, which is compatible with our clinical experience. Although detailed mechanism is to be determined, we surmise that it may be correlated with the immune-modulatory effects of inhibiting Th2 responses on the basis of our limited results.
Bu-zhong-yi-qi-tang, an ancient formula of Chinese medicine usually used in the treatment of allergic diseases, was evaluated in the treatment of patients with perennial allergic rhinitis. In this study, 60 patients allergic to house dust mite allergen confirmed by skin test and MAST test were recruited and randomized. An experimental group of 36 patients was treated with Bu-zhong-yi-qi-tang, whereas a control group of 24 patients was treated with a non-effective formula Ping-wei-san for 3 months. The nasal symptomatic scores and the responses of polymorphonuclear neutrophils (PMN) to IL-4-stimulation were measured after treatment. The nasal symptomatic scores in the experimental group were significantly improved (3.78+/-0.09 before treatment vs. 0.57+/-0.06 after treatment). In contrast, no change was found in symptomatic scores in the control group (3.17+/-0.12 before treatment vs. 2.79+/-0.14 after treatment). Moreover, total serum IgE and the IL-4-stimulated production of PGE(2) and LTC(4) by PMN was significantly suppressed in the experimental group after treatment compared to the control group. The COX-2 mRNA expression in IL-4-stimulated PMN was also significantly suppressed after Bu-zhong-yi-qi-tang treatment. These results suggest that Bu-zhong-yi-qi-tang but not Ping-wei-san was beneficial to the patients with perennial allergic rhinitis via suppressed nasal inflammation by an antiinflammatory effect.