Ioannis Zervos

Potential of long-term dietary administration of rosemary in improving the antioxidant status of rat tissues following carbon tetrachloride intoxication

In this study, 24 Wistar rats were allocated to 4 groups of 6 animals each. Groups 1 and 2 were fed a basal diet, while groups 3 and 4 were fed the basal diet supplemented further with ground rosemary at 1% level. Following 6-weeks feeding, groups 2 and 4 were injected 1 ml CCl(4)/kg bw and after six hours all animals were sacrificed. Results showed that feeding rosemary before CCl(4) treatment resulted in decline (P<0.05) of the increased aspartate transaminase, alanine transaminase and alkaline phosphatase activities and increase (P<0.05) of the reduced cholesterol and triacylglycerols in serum. It also decreased (P<0.05) lipid peroxidation and increased (P<0.05) the reduced hydroxyl anion radical and hydrogen peroxide scavenging activities in serum, liver, kidney and heart tissues. In addition, it increased (P<0.05) the reduced ABTS radical cation and the superoxide anion scavenging activities in all tissues except in heart and in kidney and heart tissues, respectively. These results suggest that dietary rosemary has the potential to become a promising functional food component.

CCl4 induces tissue-type plasminogen activator in rat brain; protective effects of oregano, rosemary or vitamin E

The high metabolic rate and relatively low antioxidant defenses of the lipid-rich brain tissue render it highly susceptible to reactive oxygen species (ROS) and oxidative stress, whereas the implication of ROS in the pathogenesis of several diseases in the central nervous system is well-established. The plasminogen activator (PA) system is a key modulator of extracellular proteolysis, extracellular matrix remodeling and neuronal cell signaling and has been implicated in the pathogenesis of these diseases. This study evaluates the role of tissue-type PA (t-PA) in oxidative stress and the protective role of dietary antioxidants in the rat brain. We used the CCl4 experimental model of ROS-induced lipid peroxidation and evaluated the antioxidant effect of oregano, rosemary or vitamin E. CCl4-treated Wistar rats exhibited elevated brain t-PA activity, which was decreased upon long-term administration of oregano, rosemary or vitamin E. PA inhibitor-1 (PAI-1) activity was also slightly elevated by CCl4, but this increase was not affected by the antioxidants. We hypothesize that the CCl4-induced t-PA activity indicates extracellular proteolytic activity that may be linked to neuronal cell death and brain damage. Vitamin E or antioxidants present in oregano or rosemary are effective in inhibiting t-PA elevation and can be considered as a potential protection against neuronal damage.

Simultaneous Determination of Retinoic Acid, Retinol, and Retinyl Palmitate in Ram Plasma by Liquid Chromatography

Abstract A liquid chromatographic method is described for the simultaneous determination of retinoic acid, retinol, and retinyl palmitate in ram plasma. Samples of 0.2 mL are extracted with 2‐propanol‐dichloromethane, the extracts are centrifuged, the supernatants are collected, evaporated, reconstituted in mobile phase, and analyzed on a C8 column using two consecutive isocratic elutions with methanol tetrahydrofuran‐acetate buffer. Detection is performed at 350 and 325 nm using wavelength change during the run. The method exhibits analytical characteristics well within acceptable limits. Overall recoveries were 73.7% for retinoic acid, 90.2% for retinol, and 87.7% for retinyl palmitate. Precision values, expressed as % relative standard deviation, were in the range of 1.16–6.18%, while limits of detection were in the range of 0.3–10.0 ng/mL for all analytes.

Crocetin administration ameliorates endotoxin-induced disseminated intravascular coagulation in rabbits.

Disseminated intravascular coagulation (DIC), a life-threatening secondary complication in several diseases, is characterized by large amounts of thrombin that lead to fibrin deposition and microthrombus formation throughout the microcirculation. Recent in-vitro studies suggest that crocin, crocetin or safranal, carotenoid constituents of the spice Crocus sativus L. (saffron), have antithrombotic properties, especially anti-Xa activity. The present study was designed to evaluate the effect of crocetin on thrombosis procedure using a rabbit model of bacterial endotoxin-induced DIC. Crocetin administration (3 mg/kg), 30 min before the beginning of endotoxin infusion, improved DIC-related haemostatic indices such as platelet blood counts (P ⩽ 0.05), blood plasma fibrinogen and protein C concentration (P ⩽ 0.05). In addition, it ameliorated DIC-associated disease and fibrin deposition in the glomeruli (P ⩽ 0.05). These results indicate that crocetin reveals a preventive antithrombotic role in vivo and prescribe further investigation on the possibility of developing crocetin-based DIC treatment modalities.

Seasonal Variation of Plasminogen Activator Activity in Spermatozoa and Seminal Plasma of Boar, Buck, Bull and Stallion

Plasminogen activators (PA) are proteolytic enzymes present in the spermatozoa and seminal plasma of various species. They play a role in the binding of the spermatozoon and its penetration through the layers surrounding the oocyte. Plasminogen activator activity (PAA) is modulated by hormones that have a seasonal variation, such as testosterone and melatonin. The present study investigates the seasonal variation of PA activity in sperm extracts and seminal plasma of four farm animal species: boar, buck, bull and stallion. Semen samples were collected every second week during a 12-month period and PAA was determined. With respect to sperm enzyme activity, the boar showed a peak from late January until the beginning of April, whereas the activity in the bull was at the highest levels from April until October and gradually declined during autumn and winter period. Plasminogen activator activity of stallion spermatozoa peaked during March and April, and remained low throughout the rest of the year, whereas in the buck sperm, PAA increased from late October until the end of January. No biologically significant variation was detected regarding the seminal PAA activity in any of the species studied. While seasonality of reproduction is typically studied from the female perspective, the present data provide compelling information about a factor that may affect the reproductive ability of the male.

Dietary omega-3 polyunsaturated fatty acids induce plasminogen activator activity and DNA damage in rabbit spermatozoa.

The aim of this study was to determine the effect(s) of dietary omega‐3 polyunsaturated fatty acids (ω‐3 PUFA) on rabbit semen. Adult rabbit bucks were assigned to two groups that were given two diets, a standard diet (control) and a diet supplemented with ω‐3 PUFA. Sperm samples were collected from all bucks with the use of an artificial vagina in 20‐day intervals, for a total period of 120 days. The enrichment of membranes in ω‐3 PUFA was manifested by the elevation of the 22:5 ω‐3 (docosapentaenoic acid [DPA]) levels within 40 days. This increase in DPA content did not affect semen characteristics (i.e., concentration, motility and viability). However, it was associated with the induction of lipid peroxidation in spermatozoa, as determined on the basis of the malondialdehyde content. Lipid peroxidation was associated with DNA fragmentation in ω‐3 PUFA‐enriched spermatozoa and a concomitant increase in plasminogen activator (PA) activity. The effects of ω‐3 PUFA on sperm cells were evident within 40 days of ω‐3 PUFA dietary intake and exhibited peack values on day 120. Our findings suggest that an ω‐3 PUFA‐rich diet may not affect semen characteristics; however, it may have a negative impact on the oxidative status and DNA integrity of the spermatozoa, which was associated with an induction of PAs activity.