Abstract: Zhankuic acid A (ZAA) is the major pharmacologically active compound of Taiwanofungus camphoratus. We analyzed the structure of human TLR4/MD-2 complex with ZAA by X-score and HotLig modeling approaches. Two antibodies against MD-2 were used to verify the MD-2/ZAA interaction. The inflammation and survival of the mice pretreated with ZAA and injected with LPS were monitored. The modeling structure shows that ZAA binds the MD-2 hydrophobic pocket exclusively via specific molecular recognition; the contact interface is dominated by hydrophobic interactions. Binding of ZAA to MD-2 reduced antibody recognition to native MD-2, similar to the effect of LPS binding. Furthermore, ZAA significantly ameliorated LPS-induced endotoxemia and Salmonella-induced diarrhea in mice. Our results indicate that ZAA, which can compete with LPS for binding to MD-2 as a TLR4/MD-2 antagonist, is a potential therapeutic agent for Gram-negative bacterial infections.

Abstract: Zhankuic acid A (ZAA) could suppress phosphorylation of JAK2 and JAK3 and signaling of downstream molecules. Moreover, ZAA could inhibit the IFN-?/STAT1/IRF-1 pathway in vivo and in vitro. Furthermore, data show that pre-treatment with ZAA could significantly ameliorate Con A-induced hepatitis in mice. The above results strongly suggest that ZAA treatment could block JAK2 and JAK3 activation, and may be a valuable therapeutic approach for the treatment of immune cell induced inflammation.