Anesthetic Propofol Enhances Plasma γ-Tocopherol Levels in Patients Undergoing Cardiac Surgery

Abstract

Background: Propofol (2,6-diisopropylphenol) is an anesthetic drug with antioxidant and antiinflammatory properties, documented both in vitro and in experimental models of ischemia-reperfusion injury and septic shock. These properties have been related to the similarity of its chemical structure to that of endogenous tocopherols, which are phenol-containing radical scavengers. This study evaluated the effects of propofol on ␣-and ␥-tocopherol (␣-and ␥-T) levels and on selected markers of oxidant-antioxidant and inflammatory status in patients undergoing cardiac surgery.Methods: Patients were randomly assigned for anesthesia with either propofol (propofol group, n ‫؍‬ 22) or sevoflurane (control group, n ‫؍‬ 21). Plasma levels of ␣-and ␥-T, individual antioxidant capacity, malondialdehyde, and interleukin 10 were measured before, during, and after anesthesia. In addition, levels of the proinflammatory prostaglandin E 2 as a marker of cyclooxygenase-2 activity and those of interleukin 10 were measured in whole blood cultured with bacterial lipopolysaccharide.Results: ␥-T levels increased significantly during surgery in propofol group (P < 0.0001 vs. control group). By contrast, ␣-T similarly decreased in both groups. Malondialdehyde and interleukin 10 increased markedly and individual antioxidant capacity decreased, without differences between groups. Prostaglandin E 2 levels measured 24 h after anesthesia induction were significantly lower in the propofol than in the control group. In vitro studies highlighted the different capacity of ␥-and ␣-T to impair prostaglandin E 2 synthesis by human monocytes challenged with bacterial lipopolysaccharide.Conclusions: The antiinflammatory properties of propofol that may be linked to its effect on ␥-T levels could be relevant in controlling the inflammatory response that accompanies tissue injury during reperfusion.

Beneficial Effect of Propofol on Arterial Adenosine Triphosphate-sensitive K+Channel Function Impaired by Thromboxane

“…23 Upon the comparison of these studies, it has become evident that higher plasmafree concentration of propofol (above 10 Ϫ5 M) is probably needed to inhibit the K ϩ channel function, indicating the benefit of this intravenous anesthetic in the clinical practice considering its protective effect toward oxidative stress in blood vessels. A recent study showing that propofol enhances plasma ␥-tocopherol levels in surgical patients, also suggests a multi-mode of action of this agent regarding the organ protection 24 ; further studies are required to clarify the whole scenario why this anesthetic is protective toward oxidative stress.…”

Promotion of interferon-gamma production by natural killer cells via suppression of murine peritoneal macrophage prostaglandin E2 production using intravenous anesthetic propofol

“…Furthermore, the suppressive effect can be expected in other cells producing PGE 2 , including DCs, because propofol also suppresses the COX activity of purified enzymes, with COX-2 being significantly more suppressed than COX-1 [28]. The inhibitory effect of propofol on COX is not surprising considering the similarity in the chemical structures of propofol and γ-tocopherol, which is reported to inhibit the activity of COX [47,48], but the precise mechanism of suppression remains unknown.…”

Antioxidant capacity of lipid- and water-soluble antioxidants in dogs with subclinical myxomatous mitral valve degeneration anaesthetised with propofol or sevoflurane

“…In the plasma of healthy men, vitamin E represents up to 75% of ACL [16,17]. A decrease in vitamin E (total tocopherol) during anaesthesia was demonstrated in dogs with MMVD [18], healthy dogs [19] and people [20,21], as well as a decrease in alpha tocopherol in people [22,23].Metabolism of anaesthetics and changes in tissue oxygenation during anaesthesia promote increased formation of ROS, which affects antioxidant defence system [7,24,25].…”