Teucrium polium Extract Attenuates Inflammation in Asthma by Reducing RORγt Transcription and Increasing IL-10 Secretion in an Ovalbumin-induced Murine Asthma Model.

Abstract

Background: One of the inflammatory diseases of the respiratory system is asthma. Teucrium polium (TP) has anti-inflammatory and anti-allergic properties and its anti-asthmatic effects have not been investigated yet. RORγt is an inflammatory transcription factor for Th17 differentiation. By secreting IL-17, Th17 leads to neutrophilic inflammation in the lungs. As an anti-inflammatory cytokine, IL-10 reduces the dissemination of inflammatory elements in the airways.

Objective: To evaluate the effect of TP extract in asthma treatment.

Methods: Thirty female Balb/c mice were distributed into 5 groups (n=6) including the control, treated with ovalbumin (OVA), and OVA+ various doses of TP (50, 150, and 300 mg/kg). All groups except the control group were sensitized to OVA solution on days 0, 7, and 14 by subcutaneous injection. The challenge was performed on days 18 to 21 by the inhalation of 1% OVA and the treatment was done with TP extract in the treatment groups, half an hour before the challenge. On day 22, the serum and spleen samples were collected to determine IL-10 serum levels and RORγt gene expression, respectively.

Results: In the treatment groups, the expression of RORγt significantly decreased when using OVA+ Tp extract (150 mg/kg and 300 mg/kg), and IL-10 serum levels significantly increased when using OVA+ TP extract (150 mg/kg) compared with the OVA group.

Conclusion: It is possible that TP extract can be effective in improving asthma by reducing inflammation.