Novel hemostatic biomolecules based on elastin-like polypeptides and the self-assembling peptide RADA-16.

BACKGROUND: Safe and effective hemostatic materials are important for reducing mortality resulting from excessive hemorrhage. In this work, new biomaterials with hemostatic effects were created by fusing the gene coding for RADA-16, a self-assembling peptide with the sequence RADARADARADARADA, to the 3'-end of the open reading frame (ORF) encoding elastin-like polypeptides through gene recombination. RESULTS: The fusion proteins, termed 36R, 60R and 96R, were solubly over-expressed in Escherichia coli BL21 (DE3) based on genetic manipulation of the high-efficiency prokaryotic expression vector pET28a (+) and bacterial transformation. Western Blot analysis showed that the over-expressed proteins were the target fusion proteins. The target proteins 36R with 94.72% purity, 60R with 96.91% purity and 96R with 96.37% purity were prepared using an inverse phase transition cycle at 65 °C followed by His-tag affinity chromatography. The proliferation results of the mouse fibroblast cell line L929 and hippocampus neuron cell line HT22 indicated that the fusion proteins did not cause obvious cell toxicity. The lyophilized spongy film of the purified 36R, 60R and 96R could stop the hemorrhage of a 2 × 2 mm bleeding wound in the mouse liver after 27.21 ± 1.92 s, 18.65 ± 1.97 s and 15.85 ± 1.21 s, respectively. The hemostasis time was 21.23 ± 1.84 s for rat-tail collagen and 14.44 ± 1.33 s for RADA-16 lyophilized on gauze. The hemostatic time of three treated groups were all significantly superior to that of the negative control without any hemostasis treatment, which spontaneously stopped bleeding after 37.64 ± 1.34 s. Statistical analysis showed that the spongy film with purified 96R exhibited an exciting hemostatic effect that was superior to rat-tail collagen and close to that of RADA-16 lyophilized on gauze. CONCLUSIONS: These results revealed that the fusion proteins achieved by gene recombination technology could serve as a promising hemostatic material.

Neuroprotective effects of active ingredients isolated from Pegasus laternarius on cultured cerebral neurons.

Seamoth (Pegasus laternarius Cuvier) is extensively used to treat various diseases on the coastland of Guangdong Province in China, such as scrofula, cough, and diarrhea. The total extract of Pegasus laternarius (EP) was subjected to column chromatography to acquire three different constituents (EPC1, EPC2, and EPC3). Cerebral neuron injury was induced by glutamate, H2O2, and serum deprivation. After treating with or without different extracts, cell viability was assessed with the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and cell apoptosis was analyzed with Hoechst 33258 staining and agarose gel electrophoresis. We also determined the levels of lactate dehydrogenase (LDH), maleic dialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). The results showed that both EP and EPC2 promoted the outgrowth of cultural neurons, increased antioxidant enzyme activity, and protected neurons from neuronal injury or apoptosis induced by glutamate, H2O2, and serum deprivation. EPC1 and EPC3 had little or no effect on neurons. These results suggest that the active ingredients obtained from Pegasus laternarius have potential neuroprotective effects on injured neurons by promoting the outgrowth of cultured neurons, increasing the activity of intracellular antioxidants, and exerting antiapoptotic effects. This neuroprotection may be attributable to specific active ingredients, such as taurine, novel ceramide, and cholesterol.

New medicinal properties of mangostins: analgesic activity and pharmacological characterization of active ingredients from the fruit hull of Garcinia mangostana L.

The fruit hull of Garcinia mangostana L. contains oxygenated and prenylated phenol derivatives, such as xanthones or xanthen-9H-ones, and is used by people in Southeast Asia as a traditional medicine for the treatment of abdominal pain, dysentery, wound infections, suppuration, and chronic ulcer. We isolated the active ingredients from the crude ethanol extract of G.mangostana L. (CEM) and investigated their analgesic effects and underlying mechanisms. CEM at intragastric (i.g.) doses of 0.5, 1, and 3 g/kg clearly exhibited antinociceptive effects in the hot-plate and acetic acid-induced writhing tests in mice. Two isolated compounds, alpha-mangostin and gamma-mangostin, exhibited analgesic effects at doses of 25 and 50 mg/kg (i.g.) in the hot-plate and formalin tests, respectively. CEM at doses of 0.5, 1, and 3 g/kg significantly inhibited xylene-induced release of inflammatory mediators. CEM, alpha-mangostin, and gamma-mangostin each dose-dependently demonstrated the ability to scavenge reactive oxygen species. In conclusion, our results demonstrate that CEM and mangostins possess potent peripheral and central antinociceptive effects in mice and suggest that xanthones may be developed as novel analgesics and anti-inflammatory drugs.