Oral Administration of <i>Trichosanthes Kirilowii</i> Fruit Extract Ameliorates Airway Inflammation and Suppresses Th2 Cell Activities in Ovalbumin‐Sensitized Mice

Trichosanthes kirilowii is a plant used in traditional Chinese medicine. Its fruits, seeds, and roots can all be used medicinally. The fruit of T. kirilowii has a moistening effect on the lung for arresting cough. However, there is no scientific research to prove that the fruit of T. kirilowii can improve asthma. Herein, we evaluated whether T. kirilowii fruit extract (TK) could reduce airway inflammation and airway hyperresponsiveness (AHR) in a murine model of asthma. Female BALB/c mice were sensitized with ovalbumin to induce asthma and treated with varying oral doses of TK from days 14 to 27 of the experiment. Additionally, IL-4/TNF-α-stimulated BEAS-2B cells were treated with different doses of TK to investigate inflammatory cytokine and chemokine secretion. TK treatment significantly mitigated AHR, eosinophil infiltration, and airway inflammation in the lungs of asthmatic mice. It also alleviated goblet cell hyperplasia and lung ROS levels while modulating Th2-associated cytokine levels in the bronchoalveolar lavage fluid. Moreover, TK effectively alleviated proinflammatory cytokine, chemokine, and eotaxin in IL-4 and TNF-α-stimulated BEAS-2B cells. Our results indicate that TK effectively improved asthma symptoms in mice through suppressed Th2-cell activation, which mitigated airway inflammation, oxidative stress, and AHR.