Ajuga iva extract lowers plasma cholesterol and improves lipoprotein profile and lecithin: cholesterol acyltransferase (LCAT) activity in rats fed high cholesterol diet

The purpose of the study was to investigate the therapeutic and preventive effects of Ajuga iva (L) Schreber (Labiatae) (Ai) extract on hypercholesterolemic model rats. For this aim, male Wistar rats were fed a high‑cholesterol (1%) diet to establish a hypercholesterolemia model supplemented or not with aqueous extract of Ajuga Iva (Ai) (5 g/kg diet) for 4 weeks.  Ai lowered plasma total cholesterol (TC) (18%) with a reduction in cholesteryl esters (CE) (29%). Low VLDL-TC and high HDL2-TC were observed in Ai group. TC/HDL’s -C ratio was 1.64-fold lower, whereas HDL’s-C/ LDL-HDL1-C was 1.82-fold higher in Ai treated rats. Triacylglycerols (TG) were reduced in plasma and in VLDL but increased in HDL2 and HDL3 with Ai supplementation. Rats exposed to Ai diet lowered VLDL-unesterified cholesterol (UC), LDL-HDL1-amount and LDL-HDL1-CE but increased HDL3-CE. Low levels of liver phospholipids (PL) and high CE concentrations were observed in Ai group. In aorta, TC was decreased by 37% with Ai. Feeding Ai diet decreased HDL3-PL and increased HDL2-CE and plasma LCAT activity. Moreover, Ai administration (5 g/kg for 4 weeks) improved liver and kidney function, as demonstrated by decreased plasma aspartate aminotransferase (AST) activity and creatinine, and resulted in an increase of urinary and sodium excretion. We conclude that, in addition to its Strong C and TG-lowering effect, Ai improves effectively the atherogenic lipoproteins profile by reducing the LDL-HDL1 amount and increasing the HDL-cholesterol. Furthermore, Ai increases the reverse cholesterol transport by enhancement of cholesterol: acyltransferase (LCAT) activity. These beneficial effects are considered potential mechanisms through which Ai acts as a protective agent against cholesterol-induced damage, ensuring cardiovascular safety.