Objective To investigate the therapeutic effect of Qingyan Mixture for laryngeal cough patients with lung dryness due to yin deficiency. Methods Sixty laryngeal cough patients with lung dryness due to yin deficiency were evenly randomized into treatment group and control group. The treatment group was given oral use of Qingyan Mixture, and the control group was given oral use of Ketotifen and Carbetapentane. The course of treatment for both groups lasted for 10 days. The overall therapeutic effect, and the effect on individual symptom or sign were evaluated after treatment. Results ( 1) In the treatment group, six patients were cured, 14 were markedly effective, 8 were improved, 2 were ineffective and the total effective rate was 93.3%. In the control group, one case was cured, 7 were markedly effective, 17 were improved, 5 were ineffective and the total effective rate was 83.3%. The overall clinical effect in the treatment group was significantly higher than that in the control group (P<0.01) . (2) As for the effect on individual symptom or sign, the treatment group showed stronger effect on dry cough than the control group ( P<0.01) , while differences of dry pharynx, throat itching, foreign body sensation in the throat, and pharyngeal signs were insignificant between the two groups (P>0.05) . (3) After treatment, the total scores of main symptoms were decreased in both groups (P<0.05 or P<0.01) compared with those before treatment. Conclusion Qingyan Mixture shows certain effect on relieving symptoms and signs of laryngeal cough patients with lung dryness due to yin deficiency.

Objective To investigate the sore-throat-relieving, anti-inflammation and antitussive actions of Qingyan mixture on the animal models. Methods Sore-throat-relieving action of Qingyan mixture was observed in SD rats with acute pharyngitis induced by spray of ammonia water at volume fraction of 15%. Anti-inflammation action of Qingyan mixture was observed on mice model of xylene-induced ear edema, and antitussive action of Qingyan mixture was carried out in mice with cough induced by concentrated ammonia spray. Results (1) The results of sore-throat-relieving action of Qingyan mixture showed that the infiltration of inflammatory cells did not happen in the blank control group, but moderate/severe inflammatory cell infiltration was shown in the model group. In the positive group, 4 rats had slight inflammatory cell infiltration while the left 6 rats had no inflammatory cell infiltration. Low-dose Qingyan mixture group had no inflammatory cell infiltration in one rat, and had slight infiltration in 9 rats. In middle-and high-dose Qingyan mixture groups, 4 rats had no infiltration and 6 had slight infiltration, inflammatory cell infiltration was markedly relieved ( P<0.01) and the sore-throat-relieving action in both groups was similar to the positive medicine of Guilin mirabilitum praeparatum (P>0.05). ( 2) The anti-inflammation rate was 69.8% in the positive control group, and was 27.3%, 60.4%, 60.0% in low-, middle- and high-dose Qingyan mixture groups respectively. The inhibitory effect of middle-and high-dose Qingyan mixture on xylene-induced mice ear edema was similar to that of the positive control group ( P>0.05) . ( 3) The cough-relieving rate was 42.6%, 139.0%, 64.3%, 104.0% in positive control group, and low-, middle-and high-dose Qingyan mixture groups respectively. Mice cough latent was obviously prolonged and cough frequency was decreased in the three Qingyan mixture groups, the differences being significant compared with the model group ( P<0.05 or P<0.01) . Conclusion Qingyan mixture has certain sore-throat-relieving, anti-inflammation and antitussive actions, which can be used for the treatment of patients with actue/chironic laryngitis and the complication of cough.