Cysteamine HCl

Cysteamine has been shown to increase intracellular glutathione levels in cystinotic cells, thus restoring the altered redox state of the cells. Also increased rates of apoptosis in cystinotic cells, which are thought to be the result of increased caspase 3 and protein kinase Cε activity, is counteracted by Cysteamine administration. Cysteamine has antioxidant properties as a result of increasing glutathione production. Cysteamine is an excellent scavenger of ^OH and HOCl; it also reacts with H₂O₂. Cysteamine increases the production of several heat shock proteins (HSP), including the murine Hsp40. Cysteamine exerts a dose-dependent effect on the doxorubicin-induced death of cancer cells, measured in both HeLa cells and B16 cells, whereas Cysteamine treatment alone had no influence on cell survival. In addition, in a doxorubicin-resistant breast cancer cell line, the addition of Cysteamine to doxorubicin results in a dramatic increase in cell death. ^[1] Cysteamine (100 μM) significantly is able to increase the intracellular GSH levels and the percentage of embryos that developed to the blastocyst stage of culture matured oocytes. ^[2]

Cysteamine is introduced as a treatment for cystinosis by depleting lysosomal cystine. Cystamine can inhibit transglutaminase activity by binding to the cysteine in its active center. Cysteamine increases brain levels of brain-derived neurotrophic factor (BDNF), which is caused by the increased expression of the heat shock DNAJ-containing protein 1 (HSJ1). Cysteamine inhibits the formation of gastric and mammary tumors that are induced chemically or after irradiation, respectively. The administration of Cysteamine is also able to inhibit the metastasis of pancreatic cancer in a mouse model by decreasing the expression and activity of metalloproteinases. ^[1]