L-Cystine

L-Cystine is an orally active extracellular form of L-Cysteine (HY-Y0337), occurring in proteins of plants and animals. L-Cystine elevates Nrf2 protein expression and activates Nrf2 transcription factor. L-cystine reduces ROS generation and protects against oxidant- or Doxorubicin (HY-15142A)-induced apoptosis. L-Cystine combined with L-theanine (HY-15121) enhances the production of antigen-specific IgG by increasing glutathione (GSH) levels and T helper 2 (Th2) mediated responses in mice. L-Cystine is promising for research of cystinuria and kidney stones^{[1][2][3][4][5][6]} In Vitro:L-Cystine (83 µM or 200 µM, 24 h or 72 h) effectively reverses the growth inhibition of both Sulfasalazine (HY-14655) and Erastin (HY-15763) in Huh6 cells^[1].
L-Cystine ( 0.8 mM, 4 h) induces Nrf2 protein expression elevation in a Keap1-dependent manner in HeLa cells^[6].
In Vivo:L-Cystine (280 mg/kg, p.o., 11 days) administrated with L-theanine (HY-15121) enhances antigen-specific IgG production partly through augmentation of glutathione (GSH) levels and T helper 2 (Th2)-mediated responses in mice^[2].
L-Cystine (200 mg/kg, p.o., 11 days) administrated with L-theanine (HY-15121) (80 mg/kg, p.o., 11 days) significantly decreases the serum IL-10/IFN-γ ratio 6 hours after DNP-KLH antigenic stimulation, but increases the serum IL-10/IFN-γ ratio 24 hours after DNP-KLH antigenic stimulation in mice^[2].