L-threo-Dihydrosphingosine (Safingol)

Safingol is a fully saturated, nonnatural analogue of sphingosine that has anticancer properties and is being investigated for its potential as an antitumor therapy. It has been shown to inhibit both protein kinase C (PKC) and sphingosine kinase. Safingol competitively interacts at the regulatory phorbol-binding domain of PKC, which is a kinase involved in tumorigenesis. Safingol has been shown to potentiate the effect of doxorubicin (DOX) in tumor-bearing animals.1 It has been reported that safingol is able to increase the activity of DOX and other chemotherapeutic agents, including mitomycin C, by generating the pro-apoptotic second messenger ceramide, even in tumor cell lines that were resistant to chemotherapy due to mutations.2 However, a study has recently claimed that safingol induces cell death of an exclusively autophagic character and lacking any of the hallmarks of apoptosis.3 Safingol inhibited the reactive oxygen intermediates (ROI) released from isolated neutrophils and phorbol ester-induced edema and neutrophil influx. Safingol also demonstrates anti-inflammatory activity. Safingol, like the natural sphinganine, is used as a biosynthetic precursor for all complex sphingolipids although the metabolism of the natural and the nonnatural compounds are different.4