EFFECT OF TASPINE ON WOUND HEALING AND FIBROBLASTPROLIFERATION

Objective To study the effect and mechanism of taspine on wound healing and fibroblast proliferation. Methods The effect of taspine on skin wound was observed in vivo. The different concentration of taspine hydrochloride was added to L 929 fibroblast cultivated in vitro, and lactate dehydrogenase was detected and MTT method was applied to observe effect of taspine on fibroblast proliferation. Results The local application of taspine 3mg/mL and 1.5mg/mL accelerated the healing of skin wounded. In vitro, 0.01～0.5μg/mL of taspine hydrochloride showed no effect on the change of lactate dehydrogenase activity and fibroblast proliferation. Conclusion Taspine is a kind of active alkaloid from leontice robustum which can enhance wound healing, its mechanism on wound healing is not by means of accelerating the proliferation of fibroblast, other mechanisms are necessary for being further studied.

Discovery of novel aporphine alkaloid derivative as potent TLR2 antagonist reversing macrophage polarization and neutrophil infiltration against acute inflammation

Toll-like receptor 2(TLR2)mediated macrophages regulate the protective immune response to infectious microorganisms,but the aberrant activation of macrophages often leads to pathological inflammation,including tissue damage.In this study,we identified antagonists of TLR2 by screening2100 natural products and subsequently identified Taspine,an aporphine alkaloid,as an excellent candidate.Furthermore,analysis of the 10 steps chemical synthesis route and structural optimization yielded the Taspine derivative SMU-Y6,which has higher activity,better solubility,and improved drug-feasible property.Mechanistic studies and seq-RNA analysis revealed that SMU-Y6 inhibited TLR2 over other TLRs,hindered the formation of TLR2/MyD88 complex,and blocked the downstream NF-κB and MAPK signaling pathway,thus suppressing the release of inflammatory cytokines.SMU-Y6 could stabilize TLR2 and bind to TLR2 protein with a Kdof 0.18μmol/L.Additionally,SMU-Y6 could efficiently reverse the M1 phenotype macrophage polarization,reduce the production of cytokines as well as infiltration of neutrophiles and alleviate the local inflammation in mice with acute paw edema and colitis.Collectively,we reported the first aporphine alkaloid derivative that selectively inhibits TLR2 with high binding affinity and superior drug-feasible property,thus providing an urgently-needed molecular probe and potential drug candidate for inflammatory and autoimmune disease therapy.