IntroductionMast cells play an important role in allergic responses.MethodsWe herein demonstrated the mechanisms of inhibitory effect of adenine on IgE/antigen‐induced degranulation and TNF‐α release in mast cells.ResultsWe found that these effects were dependent on the amino group of adenine because purine only weakly inhibited degranulation. Adenine also inhibited Ca2+ ionophore‐ and thapsigargin‐induced degranulation, however, this inhibitory effect was weaker than that of the antigen. Therefore, the inhibitory effects of adenine on degranulation may be mediated before as well as after the Ca2+ raise under the antigen stimulus. Adenine inhibited antigen‐induced Syk and the subsequent induction of AKT and ERK activation under FcϵRI‐mediated signal. Adenine also attenuated antigen‐induced increase in Ca2+. Furthermore, adenine inhibited IgE/antigen‐induced IKKα/β activation, which is involved in degranulation. Finally, adenine protected mice against anaphylactic allergic responses in vivo.ConclusionsThe present study revealed a key role of adenine in the attenuation of allergic responses through the inhibition of Syk‐mediated signal transduction and IKK‐mediated degranulation.

Abstract:The water extract powder (WEP) from normal oleic acid peanut skins at a dose of 200 mg/kg significantly inhibited the increases of serum bilirubin and the serum concentrations of AST, ALT, and GGT, marker enzymes for liver injury, in �-galactosamine (GalN)-induced liver injury rats. However, the WEP from high-oleic acid peanuts skins appeared to be less effective than that from normal ones at the same dose. trans-Resveratrol (0.67 mg/kg) and quercetin (0.67 mg/kg) were used for comparison. Their protective effects were as strong as that of the WEP from normal oleic acid peanut skins. These results indicated the ability of the WEP of peanut skins, especially from normal oleic acid peanut varieties, to ameliorate hepatic damage and suggested that they may contain the hepatoprotective agents, thought to be mainly polyphenolic compounds. Total polyphenolic content was higher in the WEP from normal oleic acid peanut skins, while the DPPH radical scavenging activity was higher in the WEP from high oleic acid peanut skins. Compared to high oleic acid peanut skins, normal oleic acid ones had a two-fold higher content of resveratrol, whereas no great differences were observed in the quercetin content analysed by reversed phase HPLC with UV detection.