TNF and asthma: Some studies have emphasized the importance of epithelial-derived cytokines in promoting Th2 immune responses.29 Several studies have identified an essential role of airway epithelial-derived cytokines in asthma pathogenesis, eg proinflammatory IL-1β and IL-6, GM-CSF (recruitment of granulocytes and monocytes), TNF-α (responsible for epithelial integrity), and TGFβ (airway remodeling).30,31 In our in vitro experiments, we validated the ability of epithelial airway cells to produce proinflammatory cytokines under T. pruni-spinosae and P. rubi-idaei extract exposure.