Morphological studies of self-assembled cyclotides extracted from Viola odorata as novel versatile platforms in biomedical applications

Cyclotide Nanotubes as a Novel Potential Drug-Delivery System: Characterization and Biocompatibility

Cyclotides are a class of cyclic peptides that can be self-assembled. This study aimed to discover the properties of cyclotide nanotubes. We performed differential scanning calorimetric (DSC) to characterize their properties. Then, we incorporated the coumarin as a probe and identified the morphology of nanostructures. The stability of cyclotide nanotubes after 3 months of keeping at -20 °C was determined by field emission scanning electron microscopy (FESEM). The cytocompatibility of cyclotide nanotubes was evaluated on peripheral blood mononuclear cells. In vivo, studies were also conducted on female C57BL/6 mice by intraperitoneally administration of nanotubes at 5, 50, and 100 mg/kg doses. Blood sampling was done before and 24 h after nanotube administration and complete blood count tests were conducted. DSC thermogram showed that the cyclotide nanotubes were stable after heating until 200 °C. Fluorescence microscopy images proved that the self-assembled structures of cyclotide can encapsulate the coumarin. FESEM proved that these nanotubes were stable even after 3 months. The results of the cytotoxicity assay and in-vivo study confirmed that these novel prepared nanotubes were biocompatible. These results suggested that the cyclotide nanotubes could be considered as a new carrier in biological fields while they are biocompatible.

Effects of Asparagus officinalis on immune system mediated EAE model of multiple sclerosis

Background

About 5 to 10 percent of the population in developed countries are affected by autoimmune diseases. One of the most important autoimmune disease with high prevalence rate is Multiple sclerosis in which there is currently no definitive cure for it, and most medications such as interferons are used only to limit the disease. The present study aims to investigate the effect of using Asparagus Officinalis fractions in an immune system mediated model of multiple sclerosis.

Material and Methods

Fractionation was performed by maceration using n-hexane, chloroform, chloroform-methanol (9: 1), n-Butanol and methanol solvents from aerial parts of Asparagus Officinalis. Thin layer chromatography, NMR and phenolic component measurement were done and two fractions were selected for checking in MS induced in vivo model.

Results

It was observed that chloroform-methanolic and N-Butanol fractions had higher content of saponin in comparison of other extracts. Also, it was showed that the methanolic and n-Butanol extracts contains the highestportion of glycosylic steroid saponins in comparison to other fractions. Regarding experimental autoimmune encephalomyelitis (EAE) score, Butanolic and methanolic fractions with doses higher that 100mg/kg showed a potent supportive effects as long as locomotor activity protection even in lower dose in comparison to phosphate buffered saline (PBS) group.

Conclusion

Considering the proved different effects of saponin compounds on the immune system we observed that those fractions altered the circulatory peripheral blood cells and also remit the clinical signs after EAE induction along with enhanced myelin sheath content in the median region of corpus callusom. It could be inferred that this fractions are promising candidates for further investigation as dose-dependent immune system regulating compounds in multiple sclerosis patients.