Hirudin (54-65)

Glioma is one of the most common intracranial tumors, and the prognosis is poor though more and more treatments are employed. ERK/MAPK signaling has been reported to be associated with glioma. In the present study, we aimed to investigate hirudin as an antineoplastic drug inhibits ERK/MAPK signaling in glioma growth in vitro. The cell proliferation and apoptosis rate were detected using MTS and Annexin V staining assay, cell cycle distribution was detected using flowcytometry assay. Furthermore, the relevant molecules of ERK/MAPK signaling were examined using Western blot analysis and immunofluorescence staining assay. We provide the first evidence that hirudin increase inactivation state of ERK1/2, down-regulate the expression of canonical ERK/MAPK signaling pathway and establish an important role for hirudin in the treatment of glioma cells.

HirudinP6 is a glycosylated and sulfated high affinity thrombin inhibitory protein isolated from Hirudineria manillensis. In this study, designing of novel bivalent thrombin inhibitory peptides based on this hirudin isoform is described. The structural and functional impact of varying linker length and glycosylation on their inhibitory potencies and binding kinetics were assessed. The bivalent peptides were obtained by tethering an active-site blocking fPRP motif with the carboxy terminal 22 residue segment of hirudin P6 (HP642-63 ) by varying number of glycine residues in the linker region. Among them, analog BiG1 -HP6 inhibited thrombin with a Ki of 5.12nM which was comparable to that of glycosylated (disaccharide bearing) and non-sulfated full length hirudin P6 protein (Ki =6.38nM). Binding kinetics studies revealed increasing linker length can decrease the association rates of peptide-thrombin interactions. Similarly, glycosylation was found to negatively modulate the inhibitory potencies of these peptides by decreasing their rates of association with thrombin.

The concept of Unani medicine is based on balancing body humours, the imbalance of which causes diseases. The application of leech therapy in medical and dental science is well recognized. Although easy and non-invasive, complications also exist. The article aims to presents a brief review on the applications of leech therapy. The physiological effect, along with its therapeutic role in cancer, diabetes and dentistry have been underlined. Complications of leech therapy have also been dealt with.

In order to study the biological performance of surface-modified biomedical polymer materials, a model of the functional mechanism of nonspecific adsorption resistance was constructed. Cell behaviors on the surface and in vivo transplantation features of intraocular lens (IOL) materials, such as hydrophobic acrylic ester and polymethyl methacrylate (PMMA), were investigated. The results of cell adhesion and proliferation studies showed that the addition of hirudin can significantly resist epithelial cell adhesion, better than the pure amination process, and thereby inhibit excessive proliferation on the surface. Experiments on the eyes of rabbits indicated that the IOL surfaces with hirudin modification reduced the incidence of cell aggregation and inflammation. Combined with a study of protein-resistance layer construction with recombinant hirudin on the material surface, the mechanism of surface functionalization was determined. The biological performance indicated that nonspecific adsorption is greatly decreased due to the existence of amphiphilic ions or hydration layers, which lead to stability and long-term resistance to non-specific adsorption.