Rosmarinic acid improves tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats

@#Objective: To evaluate the effect of rosmarinic acid on tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats. Methods: Rats were randomly divided into six groups: the control group, the asthmatic group, and the asthmatic groups treated with dexamethasone (1 mg/kg; oral gavage) or three doses of rosmarinic acid (0.5, 1, and 2 mg/kg; oral gavage). For induction of asthma, rats received intraperitoneal injections and inhalation of ovalbumin. After 21 days, bronchoalveolar lavage fluid and lung samples were collected for histopathological analyses. Moreover, total and differential white blood cell counts were determined. Results: The rosmarinic acid-treated group had significantly lower tracheal smooth muscle responses to methacholine than the asthmatic group. In addition, rosmarinic acid reduced white blood cell count and the percentages of eosinophils, monocytes, and neutrophils while increasing the percentage of lymphocytes. Ovalbumin-induced lung pathological changes were significantly improved by treatment with rosmarinic acid. Conclusions: Rosmarinic acid improves tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.

The preventive effects of natural adjuvants, G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-? (th1/th2 balance) in sensitized guinea pigs

OBJECTIVE: The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs. METHODS: The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n = 7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin. RESULTS: The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases). CONCLUSIONS: These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs. .

Effect of inhaled fluticasone and salmeterol on tracheal responsiveness and lung inflammation: Influence of administration time and allergen-free period.

Background: The effect of inhaled fluticasone propionate (FP) and salmeterol (SM) on tracheal responsiveness (TR) to methacholine and lung pathology of sensitized guinea pig was examined. Materials and Methods: Six groups of guinea pigs (n = 7) were sensitized to ovalbumin (OA). Three groups were subjected to inhaled FP and SM, one group during (A), one group after sensitization (for 18 days, B) and other group during sensitization but with 18-days delay before measurements (C). Other three groups were treated with placebo. Results: The TR to methacholine and tracheal muscle contractility were significantly higher than those of control group (P < 0.001 for all cases). The lungs of placebo groups showed variable pathological changes (nonsignificant to P < 0.001) compared to control group. TR, intra-alveolar and interabronchoal hemorrhagie (P < 0.001 in only group A) in treated groups with FP and SM were significantly decreased compared to placebo groups. The improvement in all variables in treatment groups A and C were more pronounced than group B. Conclusion: These results showed a protective effect of FP and SM on tracheal responsiveness and lung pathology during sensitization which was more effective than after sensitization.

The effect of Nigella sativa extract on tracheal responsiveness and lung inflammation in ovalbumin-sensitized guinea pigs

OBJECTIVE: To examine the preventive effect of a hydro-ethanolic extract of Nigella sativa on the tracheal responsiveness and white blood cell count in the lung lavage fluid of sensitized guinea pigs. METHODS: Three groups of guinea pigs sensitized to intraperitoneally injected and inhaled ovalbumin were given drinking water alone (group S), drinking water containing a low concentration of N. sativa extract (group S+LNS) or drinking water containing a high concentration of N. sativa extract (group S+HNS). The tracheal responses of control animals (group C) and the three groups of sensitized guinea pigs (n = 7 for all groups) to methacholine were measured by the assessment of the tracheal smooth muscle response to increasing concentrations of methacholine, and the effective concentration causing 50 percent of the maximum response (EC50) was determined. Tracheal responses to 0.1 percent ovalbumin and white blood cell counts in the lung lavage fluid were also examined. RESULTS: The tracheal response of the group S guinea pigs to both methacholine and ovalbumin was significantly higher than the response of the controls (p<0.01 for both cases). The tracheal responses of the S+LNS and S+HNS groups to both methacholine and ovalbumin were significantly decreased compared to those of the S group (p<0.05 to p<0.01). The total white blood cell and eosinophil counts in the lung lavage fluid of group S were significantly higher than those of group C (p<0.01). The white blood cell counts in both treated groups showed significant improvements (p<0.01 for both cases). CONCLUSIONS: These results demonstrate the preventive effect of the N. sativa extract on the tracheal response and lung inflammation in sensitized guinea pigs.