Anti-allergic and anti-inflammatory effects of bakkenolide B isolated from Petasites japonicus leaves

Aims of the study: To elucidate the anti-allergic and anti-inflammatory effects of Petasites genus, we studied the effects of several compounds isolated from Petasites japonicas leaves.

Materials and methods: Bakkenolide B was isolated from Petasites japonicus leaves. Antigen-induced degranulation was measured in RBL-2H3 mast cells by measuring β-hexosamidase activity. Induction of inducible nitric oxide synthase and cyclooxygenase 2 was measured by Western blotting in peritoneal Macrophages. Ovalbumin-induced Asthma model was used for in vivo efficacy test of bakkanolide B.

Results: We found that bakkenolide B, a major component of the leaves, concentration-dependently inhibited RBL-2H3 mast cell degranulation. Bakkenolide B also inhibited the gene inductions of inducible nitric oxide synthase and cyclooxygenase 2 in mouse peritoneal Macrophages. Furthermore, in an ovalbumin-induced Asthma model, bakkenolide B strongly inhibited the accumulation of eosinophils, Macrophages, and lymphocytes to bronchoalveolar lavage fluid.

Conclusion: Bakkenolide B has suppressive properties for allergic and inflammatory responses and may be utilized as a potent agent for the treatment of Asthma.