Many patients suffer from lung infl ammatory disorders including asthma, bronchitis and chronic obstructive pulmonary disorders (COPD). Several classes of drugs including bronchodilators, antitussives, steroids and leukotriene (LT) receptor antagonists have been used to treat these disorders. However, these drugs sometimes do not provide fundamental care, even though the major symptoms are alleviated (Jeffery, 2001). Thus, new effective drugs with novel action mechanism(s) are needed to treat lung infl ammatory disorders. In this regard, natural products may be applied safely for treating human lung infl ammation and bronchitis.The root barks of Broussonetia papyrifera (L.) Vent. (Moraceae) distributed in China, Japan and Korea have been used as anti-infl ammatory and antitussive agents in traditional Chinese medicine, especially for the treatment of older people having bronchitis (Editorial Committee, 1999). Recently, the 95% ethanol extracts of the radix, stems, leaves and fruits of B. papyrifera showed antinociceptive and anti-infl ammatory activity in vivo, with radix having the strongest activity (Lin et al., 2008). Lonicera japonica (Thunb.) (Caprifoliaceae) is a Broussonetia papyrifera and Lonicera japonica have long been used in the treatment of infl ammatory disorders, especially respiratory infl ammation, in Chinese medicine. Previously, phytoformula (BL) containing B. papyrifera and L. japonica was found to exert strong anti-infl ammatory activity in vitro and in vivo. In this study, the effects of BL on lung infl ammation including bronchitis were examined in vitro and in vivo. BL (10-100 μg/ml) inhibited nitric oxide (NO) production of lipopolysaccharide (LPS)-treated alveolar macrophages, MH-S cells, primarily by down-regulating inducible NO synthase. BL also inhibited production of the proinfl ammatory cytokines, TNF-α and IL-6. Against an animal model of pleural cavity infl ammation, BL (200-400 mg/kg) signifi cantly inhibited 5 h and 24 h carrageenan-induced pleurisy in rats when administered orally. Additionally, BL inhibited experimental bronchitis induced by intratracheal instillation of LPS to rats. Taken together, these results indicate that BL may be effective for the treatment of human lung infl ammation as well as bronchitis.