Effects of Grape Wine and Apple Cider Vinegar on Oxidative and Antioxidative Status in High Cholesterol-Fed Rats

Background: Oxidative stress is the result of an imbalance between the rates of free radical production and elimination via endogenous antioxidant mechanisms such as antioxidant enzymes; glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT). Antioxidants widely available in fruits, vegetables, seeds have been possessed a broad spectrum of biological, pharmacological and therapeutic properties against oxidative stress. Consumption of fruits and vegetables are essentials much as their products such as fruit juices, wines and vinegars, which contain significant amount of polyphenolic compounds. Vinegar is produced mainly from different varieties of wine by two fermentation process, ethanol and acetic acid fermentations. Followed by wine production there are mainly two vinegar production methods. One is surface also known as traditional method. The second method is submerging technique involving submerged culture where the oxygenation has been greatly improved (industrial method). Objective: The aim of the study is to determine the effects of grape and apple cider vinegar consumption against oxidative stress in high cholesterol-fed rats. Methods: Fifty-four male, adult Wistar albino rats were included in the study. Rats were divided into six groups of nine. 1 mL of 2.5% cholesterol (at 5pm) and 1 mL of different vinegar samples (at 9 am) were administered daily for 7 weeks by oral gavage. Control-diet group (CNT) received 1mL of normal saline solution concurrently with the experiment groups. Rats were sacrificed at the end of the experiment and blood samples were collected. The erythrocyte samples were washed three times in normal saline (0.9%, v/w) and then hemolyzed with 2mL of cold bidistillated water. CAT activity was measured following the method of Aebi. MDA was determined by the double heating method of Draper and Hadley. GSH-Px activity was measured according to the method of Paglia and Valentine [19]. SOD activity was analyzed according to the method of Woolliams et al.[20] Both were analyzed in Beckmann Coulter AU 5800 autoanalyzer by using RANDOX kits (Randox Laboratories Ltd. Ardmore, Crumlin, UK). Vinegars were obtained after the grape and apple vinegar fermentations using surface culture method and industrial submerge methods. Grape and apple juices were immediately inoculated with Saccharomyces cerevisiae (0.02%) for ethanol fermentation for 30 day at 25°C. After the completion of the ethanol fermentation, acetic acid fermentation of wines was initiated with the addition of two-year aged vinegar (1:3 ratio) using surface technique at 25°C and continued for 60 days at 25°C.Vinegars produced by the industrial submerge method for 24 hours at 25°Cwere transported to theDepartment of Food Engineering laboratories from the Carl Kuhne Vinegar Plant located in Afyonkarahisar, Turkey. Total antioxidant activity of vinegar samples were measured by Oxygen Radical Absorbance Capacity (ORAC) and 2,2’-azinobis (3-ethlybenzthiazoline)-6-sulfonic acid (ABTS) methods. Results: Levels of CAT, GSH-Px, SOD in CHCNT group were significantly decreased while MDA levels were significantly increased when compared to CNT group. Levels of MDA which is the end-product of lipid peroxidation was significantly decreased in the apple cider vinegar administered groups (TAV and IAV) when compared to the CHCNT (P<0.05). MDA levels of grape wine vinegar administered groups were decreased (TGV, IGV), however the difference was not significant. GSH-Px levels were significantly increased in both TGV and TAV groups, which were fed with the vinegars produced by traditional surface methods (P=0.03, P=0.001 respectively) as compared to the CHCNT. GSH-Px levels of rats fed with vinegars produced with industrial submerge methods (IGV, IAV), showed no significant difference when compared to CHCNT group. SOD levels of TGV, IGV, TAV, IAV were significantly increased as compared to CHCNT group (p<0.05). TEAC and ORAC values of vinegar samples (TGV and TAV) produced with surface methods were higher than other samples. ORAC and TEAC values of TAV sample was 5.89 µmol trolox/ml and 5.5 mM, respectively. Conclusions: Present research showed that high cholesterol diet increased lipid peroxidation and consumed the antioxidant enzymes. Although the degree of the effect of vinegars on antioxidant enzyme activity differs, the use of vinegar especially the ones produced by surface culture methods have seem to have favorable effect in vivo. These findings are in concordance with the ORAC and TEAC values of vinegars. Keywords: Oxidative stress, grape vinegar, apple cider vinegar, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT)