IFNG and pulmonary fibrosis: In bleomycin-induced pulmonary fibrosis in rats, a water extract of H. cordata significantly reduced the concentrations of superoxide dismutase, malondialdehyde, and hydroxyproline, showing stronger antioxidant activity than vitamin E. Otherwise, H. cordata can relieve the pathological changes of lung tissue caused by bleomycin (Ng et al., 2007), and the increasing level of IFN-γ and inhibition of the TGF-β1/Smad signalling pathway might be a significant mechanism.