Effect of Pakistani medicinal plants on IgE/antigen- and ionophore-induced mucosal mast cells degranulation.

Cumulative evidence has now demonstrated the stimulation of mucosal mast cells by both allergic and non-allergic triggers and their inhibition as a potential therapeutic target in many diseases like food allergy and ulcerative colitis. Hence, we screened medicinal plants from Pakistan against antigen- and ionophore-induced degranulation of mucosal mast cells. Aqueous ethanol extracts were screened. IgE/antigen- and A23187-induced degranulation of mucosal-type murine bone marrow derived mast cells (mBMMCs) were screening assays and β-hexosaminidase released from degranulated mBMMCs was measured. Real time-polymerase chain reaction was employed to examine the expression of TNF-α and IL-4 mRNA. Acetoxychavicol acetate, was examined by degranulation assays and real time-PCR. Among the ten plants screened against IgE/antigen stimulated degranulation, five plants; Alpinia galangal, Mentha arvensis, Myrtus communis, Polygonum bistorta and Syzygium aromaticum demonstrated significant (p<0.01) suppression of the degranulation at 100 μg/ml. Of them, Alpinia galangal showed significant (p<0.01) inhibition at 32 mg/ml. In A23187-induced degranulation, all plants showed significant (p<0.01) inhibition at 100 μg/ml except Tamarix dioica. Again Alpinia galangal exhibited significant (p<0.01) suppression at 32 μg/ml. In a concentration dependent assay, Alpinia galangal revealed significant suppression at 10 μg/ml against A23187-stimulated degranulation. Acetoxychavicol acetate demonstrated significant (p<0.01) inhibition at 3.2 μM in IgE/antigen-treated cells and at 10 μM in A23187-treated cells. Furthermore, both Alpinia galangal and acetoxychavicol acetate suppressed the IgE/antigen- and A23187-enhanced mRNA expression of inflammatory cytokines, TNF-a and IL-4, in mBMMCs. Our findings revealed the suppressive effect of Alpinia galangal and acetoxychavicol acetate on degranulation of mBMMCs by allergic and non-allergic stimuli, which can be utilized for future drug development against food allergy or ulcerative colitis.