Immunorestorative effects of caraway and marjoram extracts on Th2-mediated inflammation in house dust mite-triggered asthma.

Abstract

Allergic airway inflammation, a hallmark of asthma, is commonly driven by environmental allergens such as house dust mite (HDM). This study examined the protective effects of caraway (Carum carvi) and marjoram (Origanum majorana) extracts in a rat model of HDM-induced allergic airway inflammation. Daily HDM intranasal administration was applied over four weeks, with or without concurrent oral administration of the herbal extracts. Both treatments significantly reduced airway inflammation, total serum IgE, and pro-inflammatory cytokines (IL-6 and TNF-α), as well as the regulatory cytokine IL-10 in bronchoalveolar lavage fluid (BALF). RT-qPCR revealed a marked downregulation of Th2-associated cytokines (IL-4, IL-5, and IL-13) and the mucus-related gene Muc5ac, along with the restoration of the regulatory marker Foxp3. Consistently, ELISA analysis of BALF showed partial recovery of the Th1 cytokine IFN-γ. Western blotting confirmed reduced protein expression of NF-κB and STAT6 in treated groups. Histological examination showed notable improvement in lung architecture. Collectively, these findings suggest that caraway and marjoram attenuate HDM-induced airway inflammation through immunomodulatory and anti-inflammatory mechanisms, supporting their potential as complementary therapeutic agents for allergic asthma.