OBJECTIVE

The aim of this study was to determine the effects of Ajuga iva aqueous extract on lecithin : cholesterol acyltransferase (LCAT) activity and amount and composition of high-density lipoprotein (HDL)(2) and (HDL)(3), in streptozotocin (STZ)-induced diabetic rats.

METHODS

Diabetes was induced in male Wistar rats by intraperitoneal injection of STZ (60 mg/kg body weight). Diabetic rats (n = 12) were divided into two groups. The diabetic control group (D) received a 20% casein diet and the diabetic treated group received the same diet supplemented with A. iva aqueous extract (0.5 g/100 g diet) (DAi), for 4 weeks.

RESULTS

Total cholesterol and HDL(3) -C were respectively decreased by 32% and 55% in the DAi group compared with the D group, whereas HDL(2)-C was increased by 30%. The amounts of HDL(2) and HDL(3), which were the sum of apolipoproteins, unesterified cholesterol (UC), cholesteryl esters (CEs), triacylglycerols (TGs) and phospholipids (PLs), showed no significant difference. A. iva treatment increased LCAT by 33% and its cofactor-activator, apolipoprotein A-I, by 58%. HDL(3)-PL (enzyme substrate) and HDL(3)-UC (acyl group acceptor) were respectively decreased by 70% and 57%, whereas HDL(2)-CE (product of LCAT reaction) was enhanced by 30%.

CONCLUSIONS

In STZ-induced diabetic rats, A. iva improves reverse cholesterol transport by enhancing LCAT activity, leading to anti-atherogenic effects.