The anti-atherosclerotics activity of tocotrienols (TCT) compared to alpha-Tocopherol (α-TOC) in in vitro study is not much being reported especially in human endothelial cells. The aim of the present study was to study the effects of TTMF, TCT and α-TOC on monocytes adherence to stimulated endothelial cells and to investigate the correlation between monocytes adherence and adhesion molecules in endothelial cells treated with TTMF, pure TCT isomers and α-TOC. Human umbilical vein endothelial cells (HUVECs) were incubated with TTMF, TCT isomers and α-TOC (0.3-10 µM) together with lipopolysaccharide, LPS (1 μg/ml). Monocytes adherence was measured by Rose Bengal staining. Soluble ICAM-1, VCAM-1 and e-selectin and NFκB binding were measured by ELISA. TTMF and TCT isomers inhibit monocytes adhesion to LPS-stimulated HUVECs but not α-TOC. δ-TCT exhibit the highest % inhibition of monocytes adhesion compared to the other TCT isomers. Only TCT isomers show positive correlation of monocytes adhesion with certain adhesion molecules and NFκB but not TTMF and α-TOC. In conclusion, TTMF and TCT isomers exhibit reduction of adhesion of monocytes to LPS stimulated endothelial cells. The reduction of monocytes adhesion by TCT isomers especially δ-TCT are positively correlated with reduction of adhesion molecules and NFκB deactivation. It can be suggested that TCT especially the δ-TCT isomers is beneficial in the prevention of early atherogenesis in human.
Human umbilical vein endothelial cells (HUVECs) were cultured on microcarrier beads to accommodate different experiment apparatus such as rotating wall vessel. In this study, fluid operating apparatus (FPA) was used. However, the effect of inflammation and endothelial activation biomarkers in HUVECs cultured on different culture surface and containers are not well established. The effects of temperature changes on these biomarkers in HUVECs grown in FPA, a spaceflight hardware, are still unclear. The objective of this study was to compare the protein and gene expression of inflammation and endothelial activation biomarkers in (i) HUVECs cultured on microcarrier beads in conventional culture flask (CCFMC) vs. conventional culture flask (CCF) (ii) HUVECs cultured on microcarrier in FPA (FPAMC) vs. CCFMC and (iii) HUVEC cultured in FPAMC with ideal temperature (37°C) (FPAMC) vs. simulated space travel temperature(25-37°C), (FPAMC-ST). sICAM-1 and sVCAM-1protein expression in HUVECs grown in CCFMC were higher than CCF. FPAMC had higher IL-6, TNF-α, ICAM-1, VCAM-1, e-selectin, NFκB and eNOS gene expression than in CCFMC. FPAMC-ST had higher ICAM-1 and e-selectin protein expression than FPAMC- in ideal temperature. HUVECs are cultured onto microcarrier in simulated space flight temperature compared with ideal temperature had higher protein expression of sICAM-1 and e-selectin but the protein and gene expression of other biomarkers of inflammation and endothelial activation are comparable. This suggests that differences in culture surface and container are have an impact on the expression of inflammation and adhesion molecule by HUVECs.
Vitamin E is known to have potent antioxidant activity and plays an important role in reducing oxidative stress, a pivotal step in atherogenesis. However, several randomised clinical trials using α-tocopherol have failed to demonstrate consistent beneficial effects of antioxidants against atherosclerosis and clinical endpoints. Tocotrienol, a vitamin E compound analogue is shown to have more potent antioxidant activity compared to tocopherol. Finding the optimal anti-oxidative dose is crucial and may effectively be applied for cardioprotection in human. The objective of this study was to determine the optimal dose of tocotrienol rich fraction (TRF) with highest antioxidant activity in vitro using the ferric thiocyanate (FTC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2’, 7’- dichlorofluorescein diacetate (DCFHDA) assays. It was found that TRF exhibited potent antioxidant and free radical scavenging activities with an IC50 of 22.10 + 0.01 µg/ml. In all assays, TRF had optimal antioxidant activity at moderate concentrations (10-100 µg/ml). In conclusion, TRF has potent antioxidant activity, which is optimal at moderate concentrations.
The extract of Cinnamomum microphyllum showed strong antioxidant activity when it was tested against auto-oxidation of linoleic acid, superoxide, and DPPH radical scavenging activity. Further detailed investigations of the plant constituents and bioactivity studies led to the isolation and identification of known compounds consisting of three lignans, a coumarin, an ester and β-sitosterol. The structures of the compounds were determined using detailed spectroscopic analysis. The lignans were found to possess a significant antioxidant activity when tested against the three assay systems.