Pirfenidone is an inhibitor for TGF-β production and TGF-β stimulated collagen production, reduces production of TNF-α and IL-1β, and also has anti-fibrotic and anti-inflammatory properties.

Hesperetin is a flavanone extracted from the peel of citrus that exhibits inhibition of PDE4 and UGT. Hesperetin has antioxidative and anti-inflammatory effects as well. Hesperetin dose-dependently inhibited cleavage activity of the 3CLpro with IC50 value of 8.3μM in the cell-based assay.