Supplementation with Commercial Mixtures of Conjugated Linoleic Acid in Association with Vitamin E and the Process of Lipid Autoxidation in Rats

Abstract

CLA has been studied for its beneficial effects on health. However, the possibility of adverse effects, such as increased oxidative stress, must also be considered. The present work aims to assess the effect of CLA supplementation on the process of lipid autoxidation, both in the presence and in absence of an antioxidant. The investigation consisted in a biological assay with 60 rats divided into six groups: C (control), CE (control + vitamin E), AE (AdvantEdgeCLA), AEE (AdvantEdgeCLA + Vitamin E), CO (CLA One) and COE (CLA One)+ vitamin E). The CLA amount was 2% of feed consumption. Animals were supplemented for 42 days. As indicators of lipid autoxidation, peroxide (IP), malondialdehyde (MDA), 8-iso-PGF2(alpha) isoprostane and catalase were determined. Hepatic IP results indicated that CLA increased oxidation: values for CLA-supplemented groups, particularly group CO (84.38 +/- 10.97 mequiv/kg), were higher than those of the control group (54.75 +/- 9.70 mequiv/kg). In contrast, serum MDA results showed that CLA reduces oxidation both for group AE (1.8 +/- 0.67 mg of MDA/l) and for group CO (2.43 +/- 0.61 mg of MDA/l) as compared to the control group (3.85 +/- 0.24 mg of MDA/l). Serum catalase indicated a reduction of oxidation: groups AE and CO displayed 4734.23 +/- 1078.93 kU/l and 5916.06 +/- 2490.71 kU/l, respectively. These values are significantly lower than those of the control group. An increase in 8-iso-PGF2(alpha) in urine was observed, particularly in group AE (95.13 +/- 20.26 pg/ml) as compared to the control group (69.46 +/- 16.65 pg/ml). It was concluded that the influence of CLA on lipid autoxidation is dependent on supplement type, supplement dosage and chosen indicator, including its tissue and determination methodology.

High conjugated linoleic acid enriched ghee (clarified butter) increases the antioxidant and antiatherogenic potency in female Wistar rats

“…Hence, higher CAT & SOD activities in group fed with high CLA ghee diet may offer higher protection to the cells against oxidants. Similar results were reported by Santos Zago et al, [11], wherein they showed that administration of CLA to the diet of rats increased the catalase and lipid peroxidases, which finally lead to an improvement in the antioxidative process. Higher CAT and SOD activities in response to CLA diet given to rats have also been reported by Ip et al [12] and Bhatia [13].…”

Conjugated linoleic acid isomers strongly improve the redox status of bovine mammary epithelial cells (BME-UV1)

“…Hence, enhancing SOD, GPx1, and GST activity the CLA treatment may offer higher protection to the cells against oxidants. Similar results were reported by in vivo studies on laboratory animals fed with CLA at high levels (Ip et al, 1991;Santos Zago et al, 2007;Chinnadurai et al, 2013). Those studies showed that administration of CLA to the diet of rats increased catalase, SOD, and GST enzyme activities, which finally led to an improvement in the antioxidative process.…”

Effect of conjugated linoleic acid, vitamin E and their combination on lipid profiles and blood pressure of Iranian adults with active rheumatoid arthritis

“…The absence of such effects of CLAs supplementation should not be attributed to the interference of weight, physical activity, dietary intake or medication because these variables did not change during the study period and the patients had good compliance in taking their supplements. α-Tocopherol possibly has power to inhibit oxidation induced by α-tocopheroxyl radical (Singh et al 2005) and known synergistic action between vitamin E and CLAs (Kim et al 2005; Santoz-Zago et al 2007). Other studies have also shown that CLAs supplementation had no effect on HDL lipid composition (Nicolosi et al 1997; Gavino et al 2000; Stangl 2000).…”