Tae-Sook Jeong

Effect of Naringin Supplementation on Cholesterol Metabolism and Antioxidant Status in Rats Fed High Cholesterol with Different Levels of Vitamin E

Some bioflavonoids are potent antioxidants and have pharmacological effects similar to those of vitamin E. The interactive effect of naringin and vitamin E was studied with respect to cholesterol metabolism and antioxidant status. Naringin supplementation (0.1%, wt/wt) with comparable levels of vitamin E was given to rats with a high-cholesterol (1%, wt/wt) diet for 5 weeks. The amount of vitamin E included in naringin-free and naringin diets was a low (low-E) and a normal (normal-E) level. The naringin supplementation significantly lowered the concentrations of plasma cholesterol and triglyceride compared to the naringin-free group in low vitamin E-fed rats. HMG-CoA reductase activity was significantly lowered by naringin supplementation within both the low-vitamin E group (794.64 ± 9.87 vs. 432.18 ± 12.33 pmol/min/mg protein, mean ± SE; p < 0.05) and normal-vitamin E group (358.82 ± 11.4 vs. 218.22 ± 9.47 pmol/min/mg protein, mean ± SE; p < 0.05) compared to each of the naringin-free group. The HMG-CoA reductase activity was also significantly lowered by increased dietary vitamin E when compared within the naringin and naringin-free group, respectively. Neither dietary naringin nor vitamin E did significantly change the activities of hepatic antioxidant enzymes and plasma thiobarbituric acid-reactive substance level. These data indicate that naringin lowers the plasma lipid concentrations when the dietary vitamin E level is low. The HMG-CoA reductase-inhibitory effect of naringin was more potent when dietary vitamin E was at a normal level. These data may contribute to understanding the interactive effect of naringin and vitamin E on cholesterol biosynthesis in high-cholesterol-fed rats.

KRIBB-BP005m: A new inhibitor of cholesteryl ester transfer protein (CETP) produced from Trichothecium roseum F1064

Abstract KRIBB-BP005m, A novel tetracyclic compound containing a lactone which inhibits cholesteryl ester transfer protein (CETP), was isolated from a culture broth of Trichothecium roseum F1064 and the structure of KRIBB-BP005m was elucidated on the basis of 500MHz NMR experiments.

GERI-BP001, a new inhibitor of acyl-CoA : cholesterol acyltransferase produced by Aspergillus fumigatus F37

Abstract GERI-BP001, a new inhibitor (IC 50 50μM) of acyl-CoA: cholesterol acyltransferase (ACAT), was isolated from a culture broth of Aspergillus fumigatus F37 and the structure elucidated on the basis of spectroscopic data.

Amplification of farnesyl protein transferase inhibitory activity from Aspergillus fumigatus F93 by Plackett-Burman design

SummaryFermentation optimization for the fungus Aspergillus fumigatus F93 was performed to amplify the most promising biological activity. Twelve active variables were analysed and optimized by the Plackett-Burman design, consisting of 16 experiments. Farnesyl protein transferase inhibitory activity showed the best response for the design, and selected parameters were confirmed by separate experiments in the optimized fermentation condition.