According to the literature, anethole is the most common major component detected in fennel volatile oils and has been reported to show anti-inflammatory effects in vivo using the chronic lung inflammation (COPD) model (reduction of TNF-α and IL-6) (Kim et al., 2017) and the lipopolysaccharide-induced acute lung injury model (decreased neutrophils and macrophages numbers, and the inflammatory mediators MMP-9, TNF-α, and NO, as well as the NF-кB pathway) (Kang et al., 2013). Here, MMP9 is linked to chronic obstructive pulmonary disease.