ABSTRACT
The efflux of cholesterol from macrophage to liver is known as reverse cholesterol transport (RCT). Impairedcholesterol efflux leads to cholesterol accumulation in macrophages. Therefore, how to increasing cholesterol effluxmay be an effective strategy for atherosclerosis prevention. Key molecules that play a vital role in the efflux ofcholesterol from macrophage are Adenosin Tri Phosphate (ATP)-binding casette transporters A1 and G. This study wasundertaken to clarify the effect of Catechins on the expression of specific transporters such as ATP-binding cassettesub-family A member 1 (ABCA1), ATP-binding cassette sub-family G member 1 (ABCG1) from macrophage to liver,and scavenger receptor class B type I (SRB1). This research was done on Wistar rats induced atherogenic diets. SRB1is one of the transporters to facilitate the delivery of cholesterol from the macrophage to the liver. The SRB1 pathwaymediated the selective uptake of cholesteryl ester. Catechins significantly increased the mRNA expression of ABCA1and ABCG1 in aorta as well as SRB1 of liver also increased. Thus, Catechins decreased the total cholesterol levels inaorta and serum. Catechins can be developed as a potential agent to increase ABCA1 to inhibit atherogenesis process.In conclusion, this study indicates that the potential anti-atherogenic properties of Catechins could be explained, atleast in part, as being due to upregulated expression of ABCA1, ABCG1, and SRB1 through activation liver X receptorsignaling pathway
ABSTRACT
Objective: To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone. Methods: Green tea GMB-4 clones were extracted with distilled water at 90 °C. Samples were eluted into the column with 10% ethanol. Subsequently, the column was eluted with 95% ethanol and evaporated separately. Green tea extract was identified by thin layer chromatography. Catechins were separated by the stationary phase in column chromatography using polyamide with 10% ethanol eluent and 95% ethanol. The results of isolations were analyzed by high performance liquid chromatographic (HPLC) and LC-MS/MS. Analysis of catechins by HPLC was done by external standard. Results: Fraction from 10% ethanol showed that four major peaks at retention time of 1.663, 2.367, 2.950 and 4.890, indicated the presence of four catechins components including catechin, epicatechins, gallocatechin and epigallocatechin. Whereas, fraction from 95% ethanol showed two main peaks at retention time of 5.167 and 9.82, which indicated the presence of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). EGCG (m/z 459), epigallocatechin (m/z 307), ECG (m/z 443), and epicatechin (m/z 291) were isolated and separated successfully using HPLC and LC-MS/MS. Conclusions: The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG. Four major catechins were separated and identified by LC-MS/MS, such as EGCG, epigallocatechin, ECG and epicatechin. The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.
ABSTRACT
Objective: To identify the bioactive compounds in catechins isolation and its compo-nents from green tea GMB-4 clone. Methods: Green tea GMB-4 clones were extracted with distilled water at 90 ? C. Samples were eluted into the column with 10%ethanol. Subsequently, the column was eluted with 95% ethanol and evaporated separately. Green tea extract was identified by thin layer chromatography. Catechins were separated by the stationary phase in column chroma-tography using polyamide with 10% ethanol eluent and 95% ethanol. The results of isolations were analyzed by high performance liquid chromatographic (HPLC) and LC-MS/MS. Analysis of catechins by HPLC was done by external standard. Results: Fraction from 10% ethanol showed that four major peaks at retention time of 1.663, 2.367, 2.950 and 4.890, indicated the presence of four catechins components including catechin, epicatechins, gallocatechin and epigallocatechin. Whereas, fraction from 95% ethanol showed two main peaks at retention time of 5.167 and 9.82, which indicated the presence of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). EGCG (m/z 459), epigallocatechin (m/z 307), ECG (m/z 443), and epicatechin (m/z 291) were isolated and separated successfully using HPLC and LC-MS/MS. Conclusions: The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG. Four major catechins were separated and identified by LC-MS/MS, such as EGCG, epigallocatechin, ECG and epicatechin. The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.