Objective: To evaluate the effect of ligustrazin and salvia miltiorrhiza on collagen gene expression in rat pulmonary fibrosis (PF).
Methods: The tested animals were divided into 7 groups: normal control, untreated animal groups (day 7, 14 and 29), Ligustrazin, Salvia Miltiorrhiza and hydrocortisone groups. Treatment was started from day 15 to day 28. HE stain and in situ hybridization with alpha(1) (I) and alpha(1) (III) procollagen (PC) cDNA probes were applied to rat lungs on day 29. The results were quantified by a feature analysor.
Results: All the three drugs were effective, ligustrazin the best (P < 0.01), salvia miltiorrhiza the second (P < 0.01). In untreated groups both alpha(1) (I) and alpha(1) (III) PC mRNA reached the maximum on day 7. Alpha(1) (I) PC mRNA still kept high on day 29 while alpha(1) (III) PC mRNA had decreased to normal. In ligustrazin group alpha(1) (I) PC mRNA decreased to normal (P > 0.05) but in salvia miltiorrhiza and hydrocortisone groups it was still above normal level (P < 0.01). In all groups alpha(1) (III) PC mRNA had decreased to normal on day 29.
Conclusions: Inhibitive effect of ligustrazin on alpha(1) (I) PC mRNA may play an important role in treating PF. The effect of salvia miltiorrhiza is less than ligustrazin.