[Effect of ligustrazine on airway remodeling in asthmatic rats]

To observe the effect and mechanism of ligustrazine on the airway remodeling.

Thirty-two SD rats were randomly divided into 4 groups: the normal group (A), the model group (B), the ligustrazine low-dose group (C, 40 mg/kg) and the ligustrazine high-dose group (D, 80 mg/kg), with 8 rats in each group. The chronic asthmatic model was established by repeated inhalation of ovalbumin. The changes of collagen and transforming growth factor-beta(1) (TGF-beta(1)) contents in the airway wall, the thickness of smooth muscle and basement membrane, inner and outer diameter were measured by the computerized image analysis system.

The thickness of smooth muscle and basement membrane were (11.3 +/- 1.3, 11.3 +/- 1.7) microm in D group, (19.7 +/- 1.8, 19.8 +/- 1.6) microm in B group, the difference being significant (P < 0.01), as compared with A group [(10.6 +/- 1.2) microm, (9.8 +/- 1.6) microm] and C group [(11.6 +/- 0.9) microm, (12.3 +/- 1.8) microm], the difference being not significant (all P > 0.05). The difference in the ratio of inner diameter to outer diameter was significant between D group (0.77 +/- 0.06) and B group (0.63 +/- 0.05), P < 0.01. The contents of collagen type III and TGF-beta(1) were (21 +/- 5, 26 +/- 5) in D group, (55 +/- 7, 69 +/- 14) in B group, the difference being significant (P < 0.01). The differences were also significant when C group [32 +/- 8, 38 +/- 10] was compared with D group (P < 0.05) and B group (P < 0.01). The contents of collagen type I showed no difference among the 4 groups (A group: 34 +/- 13, B group: 44 +/- 8, C group: 36 +/- 8, D group: 39 +/- 8; all P > 0.05). A close correlation between TGF-beta(1) and collagen type III was demonstrated (r = 0.844 2, P < 0.01).

Ligustrazine might suppress airway remodeling by decreasing the expression of TGF-beta(1) and reducing deposition of collagen.