Effect of Ajuga iva on enzymes involved in the metabolism of cholesterol, in rat fed a cholesterol-enriched diet

Purpose This study aims to investigate the effect of Ajuga iva (Ai) on enzymes involved in the metabolism of cholesterol, in rat fed a cholesterol-enriched diet. Design/methodology/approach Male Wistar rats (n = 12), weighing 120 ± 5 g were fed on 1 per cent cholesterol-enriched diet [hypercholesterolemic (HC)] for 15 days (d15). After this adaptation phase, HC rats (total cholesterol = 6.5 ± 0.6 mmol/L) were divided into two groups fed the same diet and treated (Ai-HC) or not with (HC) with Ai for d15. Findings At day 15, in Ai-HC group compared to HC, serum triacylglycerol (TG) values were 1.4-fold lower (p = 0.002), whereas unesterified cholesterol (UC) contents were 1.8-fold higher (p = 0.0001). Serum phospholipids (PL) and cholesteryl esters (CE) contents and liver TG, UC, PL and CE values were not sensitive to Ai. TC/HDL-C and LDL-HDL1-C/HDL-C ratios were, respectively, 1.8- and 4-fold lower (p = 0.006 and p = 0.04). HDL2-C and HDL3-C amounts were enhanced by 40 and 74 per cent, respectively (p = 0.003 and p = 0.0001). HDL3-UC was 1.6-fold higher (p = 0.006); whereas PL contents were 1.4-fold lower (p = 0.003). HDL3-apo and HDL2-CE contents were similar between groups. A decreased of hydroxy-methyl-glutaryl-coenzyme A reductase and cholesterol 7α-hydroxylase activities (−44 and −25 per cent; p = 0.003 and p = 0.02, respectively) were noted. Lecithin: cholesterol acyltransferase activity was 1.5-fold higher (p = 0.001). Originality/value In HC rat, Ai is able to induce hypotriglyceridemia. However, it turns out that Ai may reduce cardiovascular risk by decreasing the reports of atherogenicity and modifying the activities of enzymes involved in the cholesterol metabolism.