Investigation of the anti-asthmatic activity of Oridonin on a mouse model of asthma

Oridonin is an extract obtained from a traditional Chinese medicinal herb, Xihuangcao. Previous studies have demonstrated that Oridonin exerts various pharmaceutical effects, such as anti-tumor and immunosuppressive effects, as well as modulating cytokine balance. The present study identified that Oridonin could regulate the T(h)1/T(h)2 cytokine balance in mice. However, as the anti-asthmatic effect of Oridonin is currently unknown a mouse model of asthma was used in the present study. BALB/c mice were sensitized using ovalbumin (OVA), then the sensitized mice were treated with Oridonin prior to OVA challenge. The in vivo study indicated that Oridonin decreased the OVA-induced airway hyper-responsiveness significantly (P<0.05). In addition, the results indicated that in Oridonin-treated mice, the eosinophil number and total inflammatory cell number in bronchoalveolar lavage (BAL) fluid decreased significantly in the Oridonin group when compared with the control group. Further study indicated that Oridonin significantly decreased the level of inflammatory cytokines, which were induced by OVA, in BAL fluid. Histological studies were performed to evaluate the effect of Oridonin on eosinophilia and mucus in the airway, the results indicated that Oridonin significantly inhibited the eosinophilia and mucus production in the lungs. Therefore the present study demonstrated that Oridonin regulates T(h)1/T(h)2 balance in mice and exhibited anti-asthmatic effects in a mouse model of asthma. These findings indicate that Oridonin may serve as a potential therapeutic compound for the treatment of asthma in future.