Investigation of HMG CoA Reductase (HMG CoA RED), Paraoxonase1, Glutathione S-Transferase (GST )enzyme activities and lipid peroxidation levels in hyperlipidemic persons

The imbalance between antioxidant defense and reactive oxygen species, which cause cellular damage and atherosklerozis, is the result of oxidative stress. Enzymatic and non-enzymatic antioxidants have important role in protecting cells against oxidative stress and preventing the development of oxidative stress related disorders. This study was formed from people who have attended Health Center due to health problems, at Yenimahalle Şentepe No. 2, Ankara Provincial Health Directorate. After examination and laboratory tests, hyperlipidemia age range is 51.4 ± 12.7 years {n: 41 (21 female, 20 male)} and the study group which have not any problem, age range were 46.8 ± 10.6 years healthy {n = 40 (20 female, 20 male )} accepted as the control group. At study and control groups the activities of HMG-CoA Reductase, paraoxonase 1 (PON 1), glutatyon s-transferase (GST) and as a lipid peroxidation marker TBARS levels were studied. When Study and control groups analysed in terms of demographic data and gender; age, weight, and BMI difference is not statistically significant, but height difference between the two groups were found significant (p <0.05). When the study analysed according to routine biochemical parameters (significant ones), total cholesterol (313.7 ± 98.4mg/dL) in the study group were found significantly high (p <0.05) versus in the control group (129.6 ± 38.1mg/dL). LDL-C and triglyceride levels were significantly high in the study group than that of control groups (respectively 181.2 ± 36.3 mg / dL and 264.0 ± 73.6 mg / dL) (respectively 64.1 ± 30.2 mg / dL, 113.4 ± 42.5 mg / dL) (p <0.05). The study and control groups were examined according to enzyme activities, both PON 1 (aryl esterase) and PON1 (paraoxonase) activities were found significantly decreased in study group than control group, respectively p=0.003 and p=0.001. However, at the control step in cholesterol biosynthesis, a significant increase is seen in the activity of the HMG-CoA Reductase than control group p = 0.04. As a result of this, both total cholesterol and LDL cholesterol levels can be shown to be significantly higher in the study group than the control group. Acting as an antioxidant enzyme, GST activity was significantly lower compared to the control group p = 0.0025. There was no significant change at the levels of TBARS which is known as the marker of lipid peroxidation (p<0,05). Diet high in fat diet and serum lipid levels in liver and also (cholesterol and triglyceride) to cause elevations in addition, the HMG-CoA Red also leads to an improvement in the activity and mRNA expression. These effects, Sp1 (specific protein 1 (SP1) mediated sterol regulatory element binding protein (SREBP) -2 activation depending on high fat diet to induce or promote activation of the HMG-CoA to cause an increase in cholesterol biosynthesis in the form disclosed. Weight control and prevent the excess rise of LDL cholesterol could reduce oxidative stress exposure and prevent the progression of atherosclerosis.