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 /2-hexosaminidase released from degranulated mBMMCs was measured. Real time-polymerase chain reaction was employed to examine the expression of TNF-a 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 microg/ml. Of them, Alpinia galangal showed significant [p<0.0l] inhibition at 32 microg/ml. In A23187-induced degranulation, all plants showed significant [p<0.01] inhibition at 100 microg/ml except Tamarix dioica. Again Alpinia galangal exhibited significant [p<0.0l] suppression at 32 microg/ml. In a concentration dependent assay, Alpinia galangal revealed significant suppression at 10 microg/ml against A23187-stimulated degranulation

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Acetoxychavicol acetate demonstrated significant [p<0.0l] inhibition at 3.2 microM in IgE/antigen-treated cells and at 10 microM in A23187-treated cells. Furthermore, both Alpinia galangal and acetoxychavicol acetate suppressed the IgE/antigen- and A23187-enhanced mRNA expression of inflammatory cytokines, TNF-alpha 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