Effects of velvet antler polypeptide on sexual behavior and testosterone synthesis in aging male mice

Twenty-four-month-old male C57BU6 mice with low serum testosterone levels were used as a late-onset hypogonadism （LOH） animal model for examining the effects of velvet antler polypeptide （VAP） on sexual function and testosterone synthesis. These mice received VAP for 5 consecutive weeks by daily gavage at doses of 100, 200, or 300 mg kg-1 body weight per day （n = 10 mice per dose）. Control animals （n = 10） received the same weight-based volume of vehicle. Sexual behavior and testosterone levels in serum and interstitial tissue of testis were measured after the last administration of VAP. Furthermore, to investigate the mechanisms of how VAP affects sexual behavior and testosterone synthesis in vivo, the expression of steroidogenic acute regulatory protein （STAR）, cytochrome P450 cholesterol side-chain cleavage enzyme （P450scc）, and 3β-hydroxysteroid dehydrogenase （3βHSD） in Leydig cells was also measured by immunofluorescence staining and quantitative real-time PCR. As a result, VAP produced a significant improvement in the sexual function of these aging male mice. Serum testosterone level and intratesticular testosterone （ITT） concentration also increased in the VAP-treated groups. The expression of STAR, P450scc, and 3β-HSD was also found to be enhanced in the VAP-treated groups compared with the control group. Our results suggested that VAP was effective in improving sexual function in aging male mice. The effect of velvet antler on sexual function was due to the increased expression of several rate-limiting enzymes of testosterone synthesis （STAR, P450scc, and 3β-HSD） and the following promotion of testosterone syothesis in vivo.

Biological effect of velvet antler polypeptides on neural stem cells from embryonic rat brain

Background Velvet antler polypeptides (VAPs), which are derived from the antler velvets, have been reported to maintain survival and promote growth and differentiation of neural cells and, especially the development of neural tissues This study was designed to explore the influence of VAPs on neural stem cells in vitro derived from embryonic rat brain Methods Neural stem cells derived from E12 14 rat brain were isolated, cultured, and expanded for 7 days until neural stem cell aggregations and neurospheres were generated The neurospheres were cultured under the condition of different concentration of VAPs followed by immunocytochemistry to detect the differentiation of neural stem cells Results VAPs could remarkablely promote differentiation of neural stem cells and most neural stem cells were induced to differentiate towards the direction of neurons under certain concentration of VAPs Conclusion Neural stem cells can be successfully induced into neurons by VAPs in vitro , which could provide a basis for regeneration of the nervous system

Comparison of Structure and Biological Activity of Natural Polypeptide from Velvet Antlers of Cervus elaphus with Those of Synthesized Polypeptide

Biochemical techniques including ion-exchange chromatography, gel filtration chromatography and re- versed-phase high-performance liquid chromatography（RP-HPLC） were used to isolate and purify the natural poly- peptide from velvet antler（nVAP） of Cervus elaphus（C, elaphus）, which has a molecular weight of 3215.8 and the primary structure of VLSAADKSNVKAAWGKVGGNAPAFGAEALLRM. The homology of the protein sequence in nVAP with known protein sequence is less than 50%, suggesting that nVAP appears to be a new bioactive substance. At a level of 0.4--50 gg/mL, nVAP promotes mitosis in epidermal ceils, chondrocytes and NIH3T3 fibroblasts pri- marily cultured in a significant way. Given that a yield of high-purity nVAP isolated from C. elaphus is 0.001%, nVAP is artificially synthesized to prepare synthetic velvet antler polypeptide（sVAP） according to its primary struc- ture. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis（SDS-PAGE） of sVAP shows a single band, and its HPLC spectrum displays a single peak. The matrix-assisted laser desorption ionization time-of-flight mass spectro- metry（MALDI-TOF-MS） was used to identify sVAP to be of a molecular weight of 3200 and the consistency between primary structures of sVAP and nVAE Bioactivity test shows that at a dose of 5--40 μg/mL, sVAP promotes the pro- liferation of primarily cultured epidermal cells and NIH3T3 cell line. From the traditional Chinese medicine theory, velvet antler from Cervus nippon（C, nippon） and velvet antler from C. elaphus are considered as the same medicine, but differences between biochemical base and pharmacological effect of these two velvet antlers have been observed. We compared the total polypeptide mapping of the two velvet antlers, discovering that nVAP is active polypeptide and only exists in the velvet antler of C. elaphus, sVAP is similar to nVAP in physicochemical property and biological activity. These studies extend the possible utility of sVAP to be the promising compound to prepare velvet antler polypeptide of C. elaphus.