Skyrin is a non-peptidic anthraquinone, mycotoxin with in vitro cytotoxic activity. It suppresses the growth of HeLa, Vero, K562, Raji, Wish and Calu-1 cell lines. Skyrin treatment induces DNA fragmentation and other morphological changes leading to apoptosis in Human HL-60 promyelotic leukemia cells. Skyrin was found to serve as an anti-diabetic agent by selectively binding to the glucagon receptor acting as its antagonist. Regular binding of glucagon to its receptor on hepathocyte plasma membrane activates adenylate cyclase indirectly. As a result, the cAMP produced activates protein kinase A with a consequent increase in both glycogen breakdown and gluconeogenesis leading to glucose output. Skyrin was shown to block this signal transduction sequence, such th at the interaction of glucagons with its receptor does not result in an increase in cAMP production. Skyrin was also found to efficiently scavenge free radical species as ?OH, ?R and of singlet oxygen (1O2). Based on Skyrin selective toxicity towards insect cell line Sf9, it may be useful as an agent for pest control.
