A Novel Insulinotropic Peptide from the Skin Secretions of Amolops loloensis Frog.

Various kinds of biologically active peptides have previously been isolated from the skin secretions of Amolops loloensis frog, such as antimicrobial peptides, bradykinin-like peptides and algesic peptides. A novel insulinotropic peptide named amolopin was identified in A. loloensis frog's skin secretion. Its primary structure sequence was determined by Edman degradation as: FLPIVGKSLSGLSGKL-NH2. BLAST search indicates that the amino acid sequence of amolopin is quite different from other known insulin secretagogues, including mastoparan, exendins and α-latrotoxin, nor does it like incretins (e.g. glucagons like peptide-1 and glucose-dependent insulinotropic ploypeptide) either. However, amolopin shows certain structural similarity with amphibian antimicrobial temporins and vespid chemotactic peptides isolated from Vespa magnifica. Amolopin can stimulate insulin release in INS-1 cells in a dose-dependent manner. Primary investigation on its action mechanisms reveals that amolopin does not increase the influx of Ca(2+). In conclusion, a novel 16-amino acid peptide with insulin-releasing activity is initially discovered from the skin secretion of A. loloensis frog. Further work is necessary to evaluate its potential as novel anti-diabetic candidate.

[Functional identification and application of horsefly as a representative form of traditional Chinese medicine].

As important traditional Chinese medicine materials, medicinal animals have been highly appreciated due to their strong bioactivities. Among these, medicinal insects have been thought to be significant, especially in preventing and treating modern diseases and tumors. Some of the most famous medicinal insects, such as horseflies, blister beetles and American cockroaches (Periplaneta americana) have been well known due to their reported effects in anti-thrombosis and fighting cancer. In general, identifying the medicinal functions and active components of medicinal insects has been a gradual processes. Originally, these medicinal insects were collected from open fields and usually their whole bodies were adopted. But, currently, most medicinal insects are under large-scale artificial propagations and only their purified active components are in use. In this article, we reviewed the historical process of the application of the horsefly in traditional Chinese medicine and tried to provide useful references for the modernization of traditional Chinese medicines via discussing the interrelationship between traditional Chinese medicine and western medicine.