Statins, vascular calcification, and vitamin K-dependent proteins: Is there a relation?

The present cross-sectional clinical study aimed to examine the connection between statin exposure, coronary artery calcification (CAC), and vitamin K-dependent proteins (VKDPs) in patients with cardiovascular (CV) conditions. Two groups of patients were studied: patients with established CV disease (CVD) and healthy patients at moderate risk for CVD (a control group). The groups were also split into statin users and non-users. The following VKDPs were measured in plasma: uncarboxylated Matrix Gla-protein (ucMGP), undercarboxylated (ucOC), and carboxylated osteocalcin (cOC), Gla-rich protein (GRP). CAC score (CACS) was determined by multislice computed tomography. Among all the participants in the study, CACS was more pronounced in statin users compared to non-users; the same was found also among the CVD patients and among the controls. While the levels of ucMGP and GRP did not differ between statin users and non-users, ucOC and ucOC/cOC were significantly elevated in statin users, indicating vitamin K deficiency. There was a positive correlation between the levels of ucOC and CACS in the entire population and in the group of statin users, but not in statin non-users. No association was found between ucMGP or GRP and CACS. Statins had also an impact on the international normalized ratio and interacted with vitamin K antagonists (VKAs). Our results are in agreement with the existing evidence about positive association between statins and vascular calcification. They enlighten to a certain extent the possible mechanisms through which statins may enhance calcium accumulation in arterial wall, namely, by inhibition of vitamin K dependent proteins and functions involved in vascular protection.

Protective effect of Aronia melanocarpa fruit juice pretreatment in a model of carbon tetrachloride-induced hepatotoxicity in rats

The main active ingredients of Aronia melanocarpa fruit juice (AMFJ) are phenolic substances, mainly flavonoids from the anthocyanin subclass.

AIM

The aim of the present study was to investigate the effect of AMFJ applied as pretreatment in a model of carbon tetrachloride (CCl4)-induced hepatotoxicity in rats.

MATERIAL AND METHODS

AMFJ was given orally to rats for 2 days at doses of 5, 10 and 20 ml/kg either alone or as pretreatment before the oral application of CCl4 (0.2 ml/kg, 2 days). The plasma activities of aspartate transaminase (AST) and alanine transaminase (ALT) were measured as markers of the liver cell damage. The levels of malondialdehyde (MDA), a lipid peroxidation marker, were determined in rat liver and plasma.

RESULTS

Administration of CCl4 caused an elevation of plasma AST and ALT activities. It also induced an elevation of MDA levels in rat liver and plasma. AMFJ applied alone in the tested doses did not cause any significant changes in the measured enzyme activities and in MDA levels. AMFJ applied as pretreatment prevented the CCl4-induced increase of AST and ALT activities, and also prevented the elevation of plasma and liver MDA levels.

CONCLUSIONS

AMFJ showed a protective effect in a model of CCl4-induced hepatotoxicity in rats. This effect might be due to the antioxidant activity of its active ingredients.

Protective effect of BP 2-94, a histamine H3-receptor agonist prodrug, in a model of carbon tetrachloride-induced hepatotoxicity in rats

BP 2-94 is a prodrug of the H3-receptor agonist (R)-alpha-methylhistamine [(R)-alpha-MeHA]. BP 2-94 displayed anti-inflammatory, antinociceptive and ulcero-protective properties in experimental animals.

AIM

The aim of the present study was to investigate the effect of BP 2-94 in a model of carbon tetrachloride (CCl4)-induced hepatotoxicity in rats.

MATERIALS AND METHODS

In order to investigate the effect of BP 2-94 it was applied to rats either alone (20, 40 and 60 micromol kg(-1), 4 days) or as a pretreatment (20, 40 and 60 micromol kg(-1), 4 days) before the application of CCl4 (0,2 ml kg(-1), 2 days).

RESULTS

BP 2-94 in the tested doses did not cause significant changes in the plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities and the liver microscopic appearance was normal. Hepatocyte damage, as evident by local areas of liver necrosis and elevated levels of plasma AST and ALT, occurred in rats following acute exposure to CCl4 (0,2 ml kg(-1), 2 days). BP 2-94 applied as a pretreatment dose-dependently reduced the necrotic changes in rat liver and inhibited the increase of plasma AST and ALT activities in response to CCl4.

CONCLUSIONS

BP 2-94 had a hepatoprotective effect in a model of CCl4-induced toxicity in rats. This effect might be due the H3-agonistic activity of its active metabolite (R)-alpha-MeHA.