Relaxant Action Of Folium Sennae Ethyl Alcohol Extract And Emodin On Airway Smooth Muscle

The traditional herb Folium Sennae is widely used in the clinical treatment and daily life.Because the Modern medical research shows that it has many biological activities such as diarrhea,antibacterial,diarrhea and heat stagnation,hemostasis,weight loss,desquamation and so on.However,we found that senna also has the effect of relaxing the airway smooth muscle(ASM).We isolated and extracted ethyl alcohol extract of Folium Sennae(EEFS)that completely and dose-dependently inhibited the precontraction in mouse tracheal rings and human airway smooth musclestrips induced by acetylcholine(ACh).In addition,the experimental results show that the monomer emodin in EEFS can completely inhibit the contraction of the ASM in mice.ACh-induced precontraction of ASM was partially inhibited by Nifedipine(a selective blocker of L-type voltage-dependent calcium channel,LVDCCs),Y27632(a specific blocker of calcium-sensitive pathway)and YM-58483(a calcium-regulated calcium channel,SOCs).The combination of three blockers can completely block the precontraction of ASM caused by ACh,and it is not affected by the dosing order.We conclude that EEFS and emodin relax the ASM by blocking LVDCCs,SOCs and calcium-sensitive pathways.In the article we further validated this inference using patch clamp and Western blot experiments.Currently,the commonly used drugs in the treatment of asthma and chronic obstructive pulmonary disease(COPD)are anti-inflammatory and antiasthmatic drugs,but the antibiotics and hormone are abused and exacerbated the disease.New drugs and treatments urgently need to be developed.This finding indicades that Folium Sennaea and emodin would be candidate of new potent bronchodilators.