Cortex phellodendri Extract Relaxes Airway Smooth Muscle

Figure 1

NBAECP inhibits high K⁺-induced contraction in TRs. (a) High K⁺ triggered contractions in a healthy (i.e., control) TR, which reached the maximum at 80 mM K⁺. Following cumulative additions of NBAECP, the sustained contraction was totally blocked. (b) An identical experiment was performed using an asthmatic TR, and a similar result was observed. (c) Dose-relaxation relationships of NBAECP from 9 control and 6 asthmatic TRs. The IC₅₀ of NBAECP was  μg/mL () in control TRs and  μg/mL () in asthmatic TRs. These data demonstrated that NBAECP could block high K⁺-induced precontraction in control and asthmatic tracheal smooth muscle.

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