Effect of fluticasone and salmeterol on tracheal responsiveness to ovalbumin and lung inflammation, administrated during and after sensitization

Abstract

The effect of duration of administration of fluticasone propionate and salmeterol on tracheal responsiveness to ovalbumin and total and differential white blood cell in sensitized guinea pig was examined. Six groups of guinea pigs (n=7) were sensitized to ovalbumin. Three groups of them were subjected to inhaled fluticasone propionate and salmeterol, one group during sensitization (A), one group after that (for 18 days, B), and the other one during sensitization but with 18 days delay before measurements (C). Three other groups were treated with placebo in the same manner. The tracheal responsiveness to ovalbumin and total and differential white blood cells of three placebo groups were significantly higher than those of control group (P<0.001 for all cases). Tracheal responsiveness to ovalbumin and total and differential white blood cell in treated groups with fluticasone propionate and salmeterol were significantly decreased compared to those of placebo groups (nonsignificant to P<0.001). The improvement in all variables in treatment groups A and C were more pronounced than group B. The results showed that fluticasone propionate and salmeterol had a prevention effect on tracheal hyperresponsiveness to ovalbumin and lung inflammation which was more pronounced when administered during than after sensitization.

Figure 1

Description of control, three placebo, and three treated sensitized groups. FP: fluticasone propionate (250 μg); SM: salmeterol (100 μg); OA: ovalbumin; NS: normal saline.

Figure 2

Individual values and mean ± SEM (big symbols with bars) of tracheal response to ovalbumin (OA) in control group and sensitized groups treated with fluticasone + salmeterol and placebo during (A), after (B), and during sensitization period and 18 days delay (C). Tracheal responsiveness to OA was measured by percent contraction obtained by 0.1% solution of OA compared to 10 μM methacholine. Comparisons of the data between control and three treated and three placebo groups were done using one-way analysis of variance (ANOVA) with Tukey-Kramer posttest, ⁺⁺: P < 0.01, and ⁺⁺⁺: P < 0.001. Comparison of the data between each treated group with fluticasone propionate + salmeterol and corresponding placebo group was done using unpaired t-test, **: P < 0.01, ***: P < 0.001, NS: nonsignificant.

Figure 3

Individual values and mean ± SEM (big symbols with bars) of total WBC count (count/mL) (b) in control group and sensitized groups treated with fluticasone + salmeterol and placebo during (A), after (B) and during sensitization period and 18 days delay (C). Tracheal responsiveness to OA was measured by percent contraction obtained by 0.1% solution of OA compared to 10 μM methacholine. Comparison of the data between control and three treated and three placebo groups were done using one way analysis of variance (ANOVA) with Tukey-Kramer posttest, ⁺⁺: P < 0.01, and ⁺⁺⁺: P < 0.001. Comparison of the data between each treated group with fluticasone propionate + salmeterol and corresponding placebo group was done using unpaired t test, **: P < 0.01, ***: P < 0.001, NS: nonsignificant.

Figure 4

Mean ± SEM of the percentages of eosinophils (a), neutrophils (b), lymphocytes (c), and monocytes (d) of lung lavage in control group and sensitized groups treated with fluticasone + salmeterol and placebo during (A), after (B), and during sensitization period and 18 days delay (C). Comparison of the data between control and three treated with fluticasone propionate + salmeterol and three placebo groups was done using one-way analysis of variance (ANOVA) with Tukey-Kramer posttest. ⁺: P < 0.05, ⁺⁺: P < 0.01, and ⁺⁺⁺: P < 0.001. Comparison of the data between each treated group with fluticasone propionate + salmeterol and corresponding placebo group was done using unpaired t-test, NS: nonsignificant, *: P < 0.05, ***: P < 0.001, and NS: nonsignificant.