Pidobenzone is a melanin synthesis inhibitor that blocks melanin deposition, eliminates melasma and brightens skin.

H-Ala-Ala-OH (L-Alanyl-L-alanine; Ala-Ala) is a nonpolar dipeptide that is absorbed by human intestinal Caco-2 cells. The transport of alanine (Ala), like proton/amino acid symport, can lead to cytoplasmic acidification.

Jatrorrhizine chloride is a potent and orally active uptake-2 transporter inhibitor. It exhibits a critical neuroprotective role in H2O2-induced apoptosis via inhibition of the MAPK pathway in HT22 hippocampal neurons.