Abstract:

This study investigated the inhibitory effect of persimmon tannin on pancreatic lipase and pancreatic cholesterol
esterase activities. The binding capacity of persimmon tannin to cholesterol and bile acids was also determined by
spectrophotometry and gas chromatography. The results indicated that persimmon tannin significantly inhibited the activity
of pancreatic lipase with an IC50 value of (0.445 ± 0.021) mg/mL in an un-competitive manner, and the inhibitory constant
(Ki) was 0.406 mg/mL. Meanwhile, it also showed a strong inhibitory effect on pancreatic cholesterol esterase in an
un-competitive manner with an IC50 value of (0.442 ± 0.017) mg/mL and a Ki value of 0.488 mg/mL. At the concentration
of 10 mg/mL, the binding rates of persimmon tannin to cholic acid (CA) and deoxycholic acid (DCA) were 58% and 94%,
respectively. Persimmon tannin also could inhibit cholesterol micellization effectively, and the percentage inhibition was
found to be 67% when the concentration was 0.20 mg/mL. In addition, the cholesterol binding ability of persimmon tannin
was stronger at pH 7.0 than pH 2.0. These results suggested that persimmon tannin might decrease lipid absorption through
inhibiting the activities of pancreatic lipase and pancreatic cholesterol esterase, and binding cholesterol and bile acids. This
may explain the strong cholesterol-lowering effect of persimmon tannin in vivo.

Key words: persimmon tannin (PT), pancreatic lipase, pancreatic cholesterol esterase, bile acids, cholesterol micellization