In vitro effects of Ginkgolide B on lymphocyte activation in atopic asthma: Comparison with cyclosporin A

The effects of Ginkgolide B (BN52021) on in vitro activation responses of h uman peripheral blood mononuclear cells (PBMC) from asthmatic patients was measured using 2-channel flow cytometric analysis of activation-associated cell surface antigens or ELISA assays for cytokines known to be expressed b y PBMC during T1 or T2 immunological activation. BN52021 is an anti-inflamm atory extract of Ginkgo biloba and has been used therapeutically. It is a k nown inhibititor of platelet activating factor (PAF), which is important in the pathogenesis of asthma, and may synergise with cyclosporin A (CyA) to inhibit pathogenic immune activation in asthmatics. We compared the inhibit ory effects of BN52021 and CyA (1 mu M each) on activation of PBMC of asthm atic patients stimulated by phorbol myristate acetate and calcium ionophore . Inhibition of production of the cytokines IL-4 and IL-5 by BN52021 was in significant compared to CyA. However, BN52021 significantly reversed the in crease in activation-associated CD45RA expression, with a trend towards dec reased expression of HLA-DR. Lymphocyte activation markers were not signifi cantly altered by CyA. Since they appear to have differing effects on activ ated cells, the anti-inflammatory effects of CyA and BN52021 in atopic asth ma is potentially additive. The present approach may be useful for prelimin ary evaluation of novel therapeutic modalities for asthma treatment.