Investigation of the Antileishmanial Activity of Medicago sativa Extract: An in vitro Study

<p>Leishmaniasis is a group of parasitic diseases caused by various species of Leishmania. Cutaneous manifestations of the disease can cause protracted wounds, difficult to heal, thus it is important to discover novel compounds that can augment in wound healing. The aim of this study is to investigate antileishmanial activity of Medicago sativa extract. Parasites were treated with different concentrations of plant extract (5, 100, 250, 500 and 1000 μg/ml) for 24, 48, and 72 hours. The characterization was done by reversed phase-high performance liquid chromatography (RP-HPLC). The IC50 values were 566.62, 445.74, and 375.74 after 24, 48, and 72 hours incubation, respectively. The results showed that the survival of this parasite can be limited by increasing the incubation time and/or the extraction dosage. The analysis of extract showed that this extract includes phenolic and flavonoid compounds. The total phenolic value was more than total flavonoids compounds. The anti-Leishmania activity of M. sativa extract may be due to the high concentration of phenolic compounds, especially caffeic acid. From our results, it can be suggested that the M. sativa extract is a potential herbal drug against leishmaniasis.</p&gt

Purification and Characterization of a New Antimicrobial Peptide from Skin Secretions of Bufo Kavirensis

Introduction: Today, research in the field of antimicrobial peptides is active. Thus, the aim of this study is to purify and determine biochemical properties (especially antimicrobial effect) of new antimicrobial peptides from skin secretions of bufo kavirensis. Methods: This is a descriptive study. The skin secretions of bufo was purified by biochemical manners and antimicrobial effects was characterized by radial dffusion assay and minimal inhibitory concentration. The sequence of peptides was also determined by using MS/MS. Results: A novel antimicrobial peptide was obtained from skin secretions. This peptide is composed of 20 amino acids. This peptide does not present any similarity with the other antimicrobial peptides from the amphibians. Thus, it was named Maximin Bk. The peptide was subjected to antimicrobial activity assays. The Buforin–Kpeptide showed considerable antimicrobial activity against Gram positive and Gram negative bacteria (minimum inhibitory concentrations (MIC), 8.1 to 20.78 µg/ml) as well as fungi (MIC, 25.7 to 35.6 mg/ml). Moreover, this peptide showed higher antimicrobial activity against Gram-negative than against Gram-positive bacteria and fungi. Maximin Bk showed virtually low hemolytic activity, which, at a concentration of 100 μg/mL, induced 5% hemolysis. Thus, a very slight haemolytic activity was obtained against human erythrocytes. Conclusion: On the basis of the biological effects, Buforin–Kcan can be regarded as the potent agent for treatment of various microbial diseases

In vitroandin vivostudy of hazardous effects of Ag nanoparticles and Arginine-treated multi walled carbon nanotubes on blood cells: Application in hemodialysis membranes

One of the novel applications of the nanostructures is the modification and development of membranes for hemocompatibility of hemodialysis. The toxicity and hemocompatibility of Ag nanoparticles and arginine-treated multiwalled carbon nanotubes (MWNT-Arg) and possibility of their application in membrane technology are investigated here. MWNT-Arg is prepared by amidation reactions, followed by characterization by FTIR spectroscopy, Raman spectroscopy, and thermogravimetric analysis. The results showed a good hemocompatibility and the hemolytic rates in the presence of both MWNT-Arg and Ag nanoparticles. The hemolytic rate of Ag nanoparticles was lower than that of MWNT-Arg. In vivo study revealed that Ag nanoparticle and MWNT-Arg decreased Hematocrit and mean number of red blood cells (RBC) statistically at concentration of 100 μg mL-1. The mean decrease of RBC and Hematocrit for Ag nanoparticles (18% for Hematocrit and 5.8 × 1,000,000/μL) was more than MWNT-Arg (20% for Hematocrit and 6 × 1000000/μL). In addition, MWNT-Arg and Ag nanoparticles had a direct influence on the White Blood Cell (WBC) drop. Regarding both nanostructures, although the number of WBC increased in initial concentration, it decreased significantly at the concentration of 100 μg mL-1. It is worth mentioning that the toxicity of Ag nanoparticle on WBC was higher than that of MWNT-Arg. Because of potent antimicrobial activity and relative hemocompatibility, MWNT-Arg could be considered as a new candidate for biomedical applications in the future especially for hemodialysis membranes