Bambusae Caulis in Taeniam extract reduces ovalbumin-induced airway inflammation and T helper 2 responses in mice

Abstract

Ethnopharmacological relevance Bambusae Caulis in Taeniam (BC) was known as traditional herbal medicine with anti-inflammatory property in the Orient. Aim of the study Allergic asthma is inflammatory disease of airways associated with enhanced T helper (Th) 2 lymphocytes responses to allergens, leading to eosinophilic infiltration and elevated serum IgE levels. Although there were some studies that BC extract had an anti-inflammatory property, there was no study on asthma. In present study, we investigated the suitability of BC extract as a therapeutic candidate in the treatment of allergic airway disease in ovalbumin-induced asthma model. Materials and methods Balb/C mice (female, 6 weeks old) were treated by ovalbumin sensitization and nebulization, and used as asthma model. The number of eosinophil in bronchoalveolar lavage (BAL) fluid and the degree of eosinophila were investigated by hematoxylin and eosin stain and the infiltration of inflammatory cells into lung tissues was examined by staining by hematoxylin and eosin solution. The levels of interleukin (IL)-4 in BAL fluid, immunoglobulin E (IgE) in serum, interferon (IFN)-γ and IL-4 production in splenocyte culture from Balb/C mice (not treated, 6 weeks old) that incubated with or without BC extract for 48 h were determined by enzyme-linked immunosorbent assay. Results The level of eosinophils was decreased by treatment of the animals with BC extract (40 mg/kg) and correspondingly, a significantly lowered degree of eosinophila was also reported ( p < 0.01). In lung tissue, BC extract reduced the increased immune cell infiltration induced by OVA ( p < 0.05). Furthermore, the levels of IL-4 and IgE in BAL fluid or serum up-regulated by OVA was decreased by BC extract. Finally, IFN-γ production was significantly increased ( p < 0.01), while IL-4 production significantly decreased ( p < 0.01), after treatment of the culture supernatants of splenocytes with BC extract. Conclusions These results indicated that BC extract reduces OVA-induced airway inflammation and Th 2 response in mice, suggesting that BC extract can be a therapeutic candidate for allergic airway disease, including asthma.