The influence of the non-Newtonian properties of blood on the flow in large arteries: unsteady flow in a 90 degrees curved tube
- FJH Gijsen, E Allanic, FN van de Vosse, JD Janssen
- J. Biomechanics
November/December 1999 © Appl. Rheol. 9, 6, 254-261 (1999) Abstract Eucalyptus oil is a commonly used remedy for common colds. For a substance to be effective therapy in obstructive airway diseases, it must reduce the viscosity of respiratory mucus. The present study evaluates the effectiveness of eucalytpus oil added phospholipid mixtures as possible substitute therapies in diseases of altered mucus viscosity by studying their effect on the viscosity of mucus gel simulants in vitro. Test formulations of surfactants consisting of phospholipid-eucalyptus oil mixtures in the ratio of 1 part of oil to 9 parts of phospholipid were prepared. The phospholipids used were dipalmitoyl phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). The effects of these phospholipid-eucalyptus oil mixtures on the viscosity of Mucus Gel Simulant (MGS – a polymeric gel consisting mainly of gum tragacanth and simulating respiratory mucus) was studied by application of steady shear rates ranging from 0.512 to 51.2 s-1 in a concentric cylinder viscometer at 37°C. The change in MGS viscosity, after incubation with surfactants, with application of shear rates was found to have a Non-Newtonian flow and to follow the power law model with R2 values > 0.8. The addition of eucalyptus oil-phospholipid mixtures caused a decrease in the MGS viscosity when compared with the effect of the phospholipid alone at both low and high shear rates. The combination of PG with eucalyptus oil and of PG with eucalyptus oil and calcium caused ratios of change in MGS viscosity < 1, i.e. they caused a decrease in the MGS viscosity. Thus, the addition of eucalyptus oil improved the ability of the phospholipids to alter MGS viscosity. The combinations of PG with eucalyptus oil and PG with eucalyptus oil in the presence of calcium were even capable of lowering mucus gel viscosity and should be further researched as possible substitute therapies for diseases of altered mucus viscosity.