Association of paraoxonase 1 (PON1) gene polymorphisms and concentration with essential hypertension.

Human serum paraoxonase 1 (PON1) is carried by high-density lipoprotein in blood circulation and is shown to be effective in preventing oxidized phospholipids carried by low-density lipoprotein particles, thus it acts as an antioxidant. Polymorphism in this gene has been investigated for many metabolic diseases, but it is not thought to be a genetic risk factor for essential hypertension. The aim of this study was to determine whether there was an association between PON1 gene polymorphisms and concentration with essential hypertension. The study population was comprised of 100 patients with essential hypertension and 100 healthy controls. One promoter region [C(-108)T] and two coding region (Q192R and L55M) polymorphisms in the PON1 gene were genotyped in individuals by using the TaqMan assay. Plasma PON1 concentration in all volunteers was also measured spectrophotometrically by the enzyme-linked immunosorbent assay method. The genotype and allele frequencies of the PON1 C(-108)T polymorphism showed significant differences between the essential hypertensive and control groups (CT vs. CC: p<0.001; T allele vs. C allele: p<0.001). There was no significant difference for the PON1 L55M polymorphism between the groups, while the heterozygote genotype of the PON1 Q192R polymorphism showed significant difference (p = 0.03). The PON1 concentration was also found to be significantly lower in hypertensive patients (p < 0.001). Decline in the level of PON1 gene may be one of the main factors in the development of essential hypertension, and the PON1 C(-108)T polymorphism may have a prognostic value in the patients with essential hypertension.

Tannic acid exhibits anti-inflammatory effects on formalin-induced paw edema model of inflammation in rats.

The aim of the study was to determine the relationship between anti-inflammatory effects of the natural polyphenolic compound tannic acid (CAS number: 1401-55-4) and myeloperoxidase (MPO) enzyme activity in paw edema model. Thirty-five female rats were divided into five groups. The paws of rats were injected subcutaneously in the plantar surface with formalin except for the control group. Indomethacin and tannic acid were intraperitoneally administered 1 h after formalin injection. The paws volume was measured by using vernier caliper. MPO enzyme activity was determined using 4-aminoantipyrine-phenol solution as the substrate for MPO-mediated oxidation by H2O2. About 17% and 13% edema inhibition has detected in the indomethacin-applied group, at the measurements run every other hour right after the treatment. An inhibition of 16% was found at the group treated with 25 mg/kg tannic acid. However, in the group treated with 50 mg/kg tannic acid, 15% and 7% of the edema inhibition was observed. Serum and paw tissue MPO activities were decreased in treated groups with indomethacin and tannic acid according to formalin control group. Our study results suggest that tannic acid may contribute to the treatment of inflammation by decreasing MPO enzyme activity, but the molecular mechanism is still not clear.