Time-dependent modulation of rat serum paraoxonase 1 activity by fasting

Abstract

High-density lipoprotein-associated paraoxonase 1 (PON1) protects the endothelium from the pro-oxidant activity of oxidised low-density lipoprotein. Whereas fasting has been related to increased oxidative stress, intermittent fasting and caloric restriction are associated to increased resistance to oxidative injury. Taking into consideration that serum PON1 activity is modulated by a restriction of caloric intake and because there is no evidence regarding PON1 response to total food deprivation, we investigated whether PON1 activity is involved in the response aimed to counteract the greater oxidative stress associated to fasting and whether serum PON1 activity is altered by the length of food deprivation. Male Wistar rats were randomly divided into five groups: fed and 6-, 12-, 24- or 48-h fasted rats. Serum PON1 activity increases within the first hours of fasting, representing a prompt adaptation designed to attenuate blood lipid peroxidation that cannot be sustained when fasting is prolonged. This PON1 response to early fasting could be part of the mechanisms triggered by periodically repeated short periods of food deprivation - intermittent fasting - which result in increased resistance to stress by stimulating antioxidant defences.

Gender Related Differences in Paraoxonase 1 Response to High‐fat Diet‐induced Oxidative Stress

“…As a whole, these results point to a greater oxidative status in the organism that, in part, would result from impaired antioxidant capacity. Although the antioxidant role of PON1 has recently been called into question (43), the present results and others previously described in different physiological situations characterized by changes in the oxidative status (18,19,20,44), suggest that this enzyme would be involved in the response to oxidative stress.…”

Fasting Status and Thermally Oxidized Sunflower Oil Ingestion Affect the Intestinal Antioxidant Enzyme Activity and Gene Expression of Male Wistar Rats

“…Th omas-Moy a et al (32) described that, after a 15 h fast, GPx activity in male Wistar rats was significantly lower than that observed in fed animals. In control animals, fasting affected non-Se-GPx activity, while the joint effect of fasting and altered oil consumption modified total, Se-and non-Se-GPx activities.…”

“…Thus, it can be suggested that, although total tocopherol content was decreased in the sunflower oil after frying, the presence of antioxidants in diet counterbalanced the prooxidant effect of thermal oxidized fatty acids in intestinal mucosa. Thòmas-Moyá et al found that TBARS levels displayed a nonsignificant tendency to increase (2.25 vs 1.82 nmol/g of tissue) after a 12 h fasting period. Autooxidized oil ingestion may negatively affect antioxidant defense.…”

The Human Paraoxonase Gene Cluster As a Target in the Treatment of Atherosclerosis

“…Fasting increases serum PON1 activity; effects can be seen within 6 h in rats. However, this is only a shortterm adaptation designed to attenuate blood lipid peroxidation caused by fasting and cannot be sustained long term (331).…”