LSF, a chiral metabolite of pentoxifylline, acts as a potent anti-inflammatory agent.{17416,18148} (R)-LSF is the biologically active isomer of LSF.{17416,18148} It is a potent inhibitor of the generation of phosphatidic acid (IC50 = 0.6 µM) from cytokine-activated lysophosphatidic acyl transferase (LPAAT), which has been shown to protect mice from endotoxic shock.{17415} (R)-LSF suppresses the production of the proinflammatory cytokine IFN-y, inhibits interleukin 12-mediated STAT-4 activation, and enhances glucose-stimulated B-cell insulin secretion, reducing the onset of diabetes in a non-obese diabetic mouse model.{17414,17416}