Medicinal plants as surface activity modifiers

Surface active agents have been used in pharmaceutical formulations for different purposes, so the study of the effect of these agent on biological membranes is necessary. The aim of this study is the evaluation of aqueous extract of Tribulus terrestris L., Trigonella foenum-graecum L. and Echium amoenum Fisch, that contain saponins on red blood cells (RBC) as a model of biological membranes. Also some physicochemical properties of the extracts including emulsification index (E24) and foam producing activity (Fh) were investigated. The aqueous extracts were prepared by maceration and then lyophilized. The different concentration of extracts in McIvan’s buffer solution were incubated with RBC in different temperatures (25 and 37°C) for different time periods (15 and 30 min). The absorbance of the samples by UV spectrophotometer determmine the degree of hemolysis. In comparison of three studied extracts, T. terrestris L, have shown the highest hemolytic effect (12.45% in 37°C and 30 min). The values of E24 and Fh showed the extract of T. terrestris L. has the highest emulsification index (24.89%) and the highest foam producing activity (14.42 mm). The extract of H. persicum, with lower hemolytic effect may be preferred in pharmaceutical preparation but if the hemolytic effect was excluded, A. dracunculus is preferred

Screening Three Strains of Pseudomonas aeruginosa: Prediction of Biosurfactant-Producer Strain

Problem statement: The chemical surfactants have some disadvantages; especially, toxicity and no biodegradability. Approach: Biosurfactants were the structurally diverse group of surface-active molecules synthesize by micro-organisms. The microbial surfactants were interesting, because of the biodegradable and have many applications in industry, agriculture, medicine. Results: In the present study, the production of biosurfactant by three strains of Pseudomonas aeruginosa (PTCC 1074, 1310 and 1430) was investigated. The hemolytic and foam forming activity of different strains were studied and consequently, P. aeruginosa PTCC 1074 was selected as the suitable strain. P. aeruginosa PTCC 1074 was grown in the nutrient broth medium and biosurfactant production was evaluated every 24 h by emulsification index and surface tension for the best of production time. After that, in order to get maximum production of biosurfactant, the selected strain was grown with different additives in nutrient broth and the best culture medium was found. The biosurfactant was isolated from the supernatant and its amphipathic structure was confirmed by chemical methods. Conclusion: Biosurfactant produced by Pseudomonas aeruginosa PTCC 1074 would be considered as a suitable surfactant in industries due to its low toxicity