Interaction of skullcap (Scutellaria baicalensis Georgi) and buckwheat (Fagopyrum esculentum Moench) extracts with lipid bilayers

Abstract

In this paper, we report the effect of skullcap (Scutellaria baicalensis Georgi) root (SR) and buckwheat (Fagopyrum esculentum Moench) husk and stalk (BH and BS) extracts on lipid organization and fluidity of model membranes, examined by monitoring of the thermotropic phase transition of dimyristoylphosphatidylcholine (DMPC) with differential scanning calorimetry, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and fluorescence spectroscopy. Despite the very high biological activity of these extracts, such a study has not been undertaken previously. Calorimetric results on the thermotropic parameters of DMPC membranes suggest that BH and BS extracts modify them to a greater extent than SR. Fluorescence and ATR-FTIR results confirm that the compounds contained in the SR extract concentrate in the hydrophilic area of the DMPC bilayer, causing an increase in the order of the polar heads of the lipid, and they do not penetrate the hydrophobic area. Compounds contained in the BS and BH extracts also concentrate in the hydrophilic area of the bilayer; however, they partially affect the hydrophobic-hydrophilic interface of the bilayer as well as the upper part of the acyl chain region.

Application of the DSC and spectroscopy methods in the analysis of the protective effect of extracts from the blueberry fruit of the genus Vaccinium in relation to the lipid membrane

“…The effect of WB, HB and LB extracts on packing arrangement and fluidity of lipids in the model lipid membrane (DPPC and egg phosphatidylcholine (EPC) liposomes) was investigated using the fluorimetric method described earlier in Bonarska-Kujawa et al [22,23] with minor modifications. Small unilamellar liposomes (SUVs) used for fluorimetric experiments were composed of DPPC or EPC lipids.…”

“…Samples for DSC consisted of multilamellar vesicles (MLVs) made of DPPC and modified with WB, HB and LB extracts in accordance with the procedure described earlier [23,25]. The measurements were taken on 34-36 mg samples using Mettler Toledo Thermal Analysis System D.S.C., 821 e , operated at scanning speed of 2°C min -1 .…”

“…The main phase transition (T m ) is from the lamellar gel phase to liquid (fluid) phase; however, DPPC shows a more complicated phase behavior: There is also so-called intermediate (ripple) P b 0 phase, in which the surface of the bilayer is distorted by a periodic ripple, and L b 0 phase in which the molecules are tilted at an angle of about 30°relative to bilayer normal. The change from L b 0 to P b 0 is commonly referred to as the pretransition (T p ) [22][23][24][25][31][32][33][34][35].…”

Influence of cytotoxic butyltin complexes with 2-sulfobenzoic acid on the thermotropic phase behavior of lipid model membranes

“…The method was applied as described earlier [14,20] with a few modifications. Mixtures of DPPC dissolved in chloroform (1 mg) and butyltin complexes dissolved in ethanol were placed on ZnSe crystal and were dried under nitrogen for a few minutes and under vacuum for 24 h. The dried films of DPPC or BTsbz/DPPC were hydrated in distilled water above the main phase transition of DPPC for 4 h. Molar ratio of BTsbz/DPPC was 0.2.…”

“…The effect of the BTsbz on the lipid bilayer phase transition was examined mainly by the differential scanning calorimetry (DSC)-a method useful for studying the nature of biological systems such as lipids or proteins [14][15][16][17], and additionally by fluorescence and infrared spectroscopy. The above-mentioned methods have been employed to systematically monitor the influence of the BTsbz on different membrane regions.…”