Effect of San-Ao-Tang on Immediate and Late Airway Response and Leukocyte Infiltration in Asthmatic Guinea Pigs

Abstract

San-Ao-Tang (SAT), a traditional Chinese medicines, has been used to treat patients with the bronchial asthma for several centuries. However, the therapeutic mechanisms of this Chinese medicine are still far from clear. To understand the mechanism of antiasthmatic property of SAT, a guinea pig model of allergic asthma was used to investigate the effects of SAT on Dermatophagoides pteronyssinus-induced immediate and late asthmatic responses and airway inflammation. Our results showed that administration of SAT (10 g/kg) extracts significantly inhibited the antigen induced immediate asthmatic responses (IAR) in actively sensitized guinea pig. Examination of bronchoalveolar lavage fluid (BALF) revealed that SAT significantly inhibited the increase in neutrophil in the airway at 1, 2, 4, 6, 8 hr after antigen challenge. Histopathologic examination showed SAT suppressed the neutrophil infiltration into lung tissue. These results suggest that the antiasthmatic effect of SAT be mainly due to its bronchodilator effect and its ability to inhibit the neutrophil into the airway. The precise mechanism of action of SAT in asthma remains to be elucidated.

Inhibitory effects of inhaled complex traditional Chinese medicine on early and late asthmatic responses induced by ovalbumin in sensitized guinea pigs

“…Different sensitization processes may induce different severities of antigen reactions. Booster sensitization by an aerosolized antigen has been widely used in recent years, as this antigen delivery route is similar to the natural physiological way, and this method can elicit responses including elevated levels of allergen-specific IgE, eosinophilic airway inflammation, and AHR [8,14-16]. On the other hand, delivery of medication directly to the airways has a quicker action than the oral route, as the drug can act immediately upon the target area.…”

“…Most of the Chinese herbs used for the treatment of bronchial asthma are either administered orally or through a gastric tube for research purposes. For example, several studies have demonstrated the anti-asthmatic effects of traditional Chinese medicine formulas such as XQLT by administering the medicine via the gastric route to guinea pigs [14-16], and simplified herbal medicine treatment also reduced several asthma features in a mouse model [27,28]. Currently, many of the western medicines used for the treatment of asthma are inhaled.…”

“…These reactions are due to the release of cytotoxic granular-associated proteins by eosinophils, including major basic protein, eosinophil cationic protein, and eosinophil peroxidase, which have a profound effect on the airway [16,37,38]. Furthermore, eosinophil activation results in the release of other mediators, such as leukotriene C 4 and platelet-activating factor, which can cause contraction of the airway smooth muscles [39,40].…”

“…In addition, in most cases, mild-to-moderate asthma can be controlled by inhalational steroids; however, long-term steroid therapy is often associated with multiple side effects that have long-term repercussions on one's health [13]. In contrast to western medicines, Chinese herbs have been used to treat asthma for many centuries, some of which have been proven to inhibit the EAR and LAR in asthma patients subjected to specific allergens [8,14-16]. Freeze-dried powder of a traditional Chinese medicine was administered via a gastric tube before or after challenge in this study.…”

“…Freeze-dried powder of a traditional Chinese medicine was administered via a gastric tube before or after challenge in this study. The results showed that the Chinese medicine attenuated the increased respiratory resistance and the amount of eosinophilia induced by the allergens [8,14-16]; however, the mechanisms are unclear. In this study, a formula of complex traditional Chinese medicines (CTCM) was used.…”