Protective effect of omega-3 fatty acids on diethylnitrosamine toxicity in rats.

OBJECTIVES: In this study, it was aimed to investigate the effect of n-3 fatty acids (n-3 FA) on diethylnitrosamine (DEN) toxicity with respect to alterations including nitric oxide (NO) formation, uric acid level as well as some liver related enzymes such as aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities in rats. MATERIALS AND METHODS: Forty male Wistar albino rats were used as animal materials. Animals were divided into 4 groups and treated as follows: Rats in group 1 (control) were intraperitoneally (i.p) injected with single dose of saline; rats in group 2 were i.p. injected with DEN at a dose of 150 mg/kg/body weight; rats in group 3 were treated with DEN (via single i.p. injection at 150 mg/kg/body weight) plus n-3 FA (at a dose of 0.4 g /kg/day via subcutaneous route in fish oil) for 7 days, and group 4 received n-3 FA via s.c. route at a dose of 0.4 g/kg/day in fish oil for 7 days. The plasma samples were analyzed for NO, uric acid levels as well as for activities of AST, ALT and ALP. RESULTS: Uric acid level was lower in DEN group than in control. In addition, NO level and AST, ALT, ALP activities in DEN group were significantly higher than in control. Nitric oxide concentration, ALT and ALP activities in DEN + n-3 FA treated rats were lower than in DEN alone. Uric acid level in DEN + n-3 FA group was higher than in DEN group. CONCLUSIONS: These results suggest that n-3 fatty acids could ameliorate the toxic effects of DEN in part by means of its free radical scavenging activity and may be of therapeutic value in the protection of liver against toxic effects of DEN.  

Nitric oxide concentrations, estradiol-17ß progesterone ratio in follicular fluid, and COC quality with respect to perifollicular blood flow in cows.

The objectives were to investigate relationships among concentrations of nitric oxide (NO), estradiol 17 beta (E2), and progesterone (P4) in follicular fluids (FF), and quality of cumulus oocyte complexes (COCs) with respect to perifollicular blood flow (FBF). In Experiment I, follicles (138) were classified according to the presence or absence of FBF (assessed with transvaginal Doppler ultrasonography) and diameter of follicles (small, 2-4 mm; medium, 5-8 mm; and large, ≥9 mm). Concentrations of NO in FF did not differ significantly among these size categories. However, NO concentrations in FF with FBF (54.4 ± 7.4 µmol/l) were higher (P<0.05) than in those without FBF (36.6 ± 4.1 µmol/l). There was a positive correlation (r=0.30, P<0.05) between NO concentrations and the E2:P4 in FF. Rate of E2 active (E2:P4 ≥ 1) follicles were numerically 1.2 (0.8-1.8) times higher in follicles with FBF (38.1%) compared to those without FBF (25.0%). Moreover, rates of E2 active follicles were 6.1 (0.7-55.2) and 1.3 (0.1-17.3) times higher (P<0.06) in large (43.3%) and medium (14.3%) compared to small follicles (11.1%), respectively. In Experiment II, quality of COCs from 2 to 8 mm follicles, obtained by transvaginal ovum pick up (OPU), was investigated with respect to FBF. Odds ratio to obtain higher quality COCs from follicles with FBF (47.1%) was 3.3 (1.1-9.6) fold higher (P<0.05) compared to those from follicles without FBF (14.6%). In conclusion, E2:P4, and NO concentrations in FF, as well as FBF, could be used to determine the functionality of ovarian follicles in cows. Moreover, determination of FBF could be useful to predict quality of COCs in cattle.

Changes in follicular blood flow and nitric oxide levels in follicular fluid during follicular deviation in cows.

Two experiments were conducted to test the hypothesis that there are dynamic changes in follicular blood flow during follicular deviation and that nitric oxide (NO) in follicular fluid (FF) plays a role in regulation of follicular blood flow. In Experiment I, follicular blood flow of the two largest follicles was monitored by using Power Doppler ultrasonography during follicular deviation in sixteen follicular waves during eight estrous cycles in eight cows. Blood flow did not differ (P>0.05) between the dominant follicle (DF) and the largest subordinate follicle (SF) until the beginning of the deviation of the follicular size, but was higher (P<0.05) in DF than in the largest SF one and two days after the beginning of diameter deviation in ovulatory (n=5) and atretic (n=11) waves; respectively. In Experiment II, FF was aspirated from DF and the largest SF on the day of diameter deviation (DF, n=6; SF, n=6) and two days later (DF, n=12; SF, n=9). Nitric oxide did not differ (P>0.05) between DF and the largest SF on the day of diameter deviation but, one or two days after observed diameter deviation NO concentrations were lower (P<0.01) in DF compared to the largest SF. On the day of diameter deviation and two days later E2 levels in FF were higher (P<0.01) in DF than in the largest SF. P4 concentrations in FF were higher (P<0.05) in DF than in the largest SF on the day of diameter deviation, but did not (P>0.05) differ two days later. E2/P4 ratio in FF was the same (P>0.05) in DF and the largest SF on the day of diameter deviation, but was higher (P<0.01) in DF than in the largest SF one or two days later. In conclusion, area of follicular blood flow of DF and the largest SF increased in parallel with follicular size during follicular deviation. Furthermore, there were relationships between changes in follicular blood flow, NO concentrations and E2/P4 ratio in FF following the beginning of diameter deviation in cattle.

Effects of reduced glutathione on nitric oxide level, total antioxidant and oxidant capacity and adenosine deaminase activity.

The aim of this study was to determine the effect of exogenous GSH, an important antioxidant containing thiol group, on total antioxidant capacity (TAC) and total oxidant capacity (TOC), adenosine deaminase (ADA), a significant indicator of cellular immunity, and nitric oxide (NO) concentrations in rabbits. Sixteen healthy New Zealand rabbits were divided into 2 groups as control and GSH-treated group. Animals in control group received single intraperitoneal (ip) administration of 0.9% saline. Rabbits in GSH-treated group received reduced L-glutathione (10 mg/kg) (ip). Blood samples were taken from the marginal ear vein 0, 3, 6 and 12 hours after injection. Plasma TAC and NO levels were not statistically different between control and GSH group at 0 and 12 hours. Plasma TAC level was found to be significantly higher (p < 0.05) while NO level was found to be significantly lower (p < 0.05) in GSH treated group when compared to control group at 3 and 6 hours. Plasma TOC and ADA activity were not statistically different between control and GSH group during experiment. In conclusion, exogenous GSH resulted in an alteration of TAC and NO but not TOC and ADA, so exogenous GSH may be a valuable enhancer of the antioxidant system.

Acute tamoxifen treatment increases nitric oxide level but not total antioxidant capacity and adenosine deaminase activity in the plasma of rabbits.

Tamoxifen is a synthetic non steroidal anti-estrogen used to treat patients with breast cancer and healthy subjects with high risk of breast cancer. It was aimed to study the short term effects of tamoxifen on the plasma total antioxidant capacity (TAC), nitric oxide (NO) and the adenosine deaminase activity (ADA) in healthy rabbits. Sixteen healthy New Zealand rabbits were allocated to 2 groups including controls and tamoxifen treated animals. Controls received a single application of 0.9% saline via oral route while the treated rabbits received orally tamoxifen (dissolved in 0.9% saline, at a dose of 5 mg/kg). Blood samples were collected at 6 and 24 hours following the treatments. Plasma TAC and ADA were not affected by Tamoxifen treatment. However, NO level in tamoxifen treated group was increased at 24 hours following tamoxifen treatment as compared to controls. In conclusion, acute tamoxifen treatment may not affect the antioxidant status and cellular immunity, as evidenced by unaltered TAC and ADA. However, NO level was increased as early as 24 hours following tamoxifen treatment.

Omega-3 fatty acid application reduces yolk and plasma cholesterol levels in Japanese quails.

The aim of this study was to determine the effects of fish oil, rich in omega-3 fatty acids, on the cholesterol levels in egg yolk and plasma in Japanese quail. Additionally, the effects of these fatty acids on selected biochemical parameters, and yolk and quail weights were investigated. Thirty healthy laying Japanese quails were divided into two groups including control and omega-3 fatty acid treated group. Fish oil capsules were administrated orally to the quails in the omega-3 treated group every other day for 3 weeks. Yolk cholesterol level was found to be significantly lower in the omega-3 treated group compared to the control. Plasma cholesterol levels were lower; plasma calcium levels were higher at 3rd week in omega-3 fatty acid treated group than those in control. On the other hand, plasma phosphorus and glucose levels in omega-3 fatty acid group were significantly lower at 3rd week than those at the beginning of experiment. In conclusion, it was found that orally supplemented omega-3 fatty acid reduced the levels of cholesterol in egg yolk and plasma in quails.

Effects of therapeutic dose of ivermectin on plasma nitric oxide and total antioxidant capacity in rabbits.

BACKGROUND: Ivermectin, an acaricide and anthielmintic drug of the family of avermectins may produce free radicals thus resulting cytotoxic effect on the parasite. Nitric oxide (NO) acts as free radicals and as host defense mechanisms. The antioxidant capacity (TAC) can be described by the analysis of single components in the defense systems against free radicals. It was aimed to study the effects of therapeutic doses of ivermectin on the plasma adenosine deaminase (ADA) and gamma glutamyl transpeptidase activities (GGT), total antioxidant capacity (TAC), nitric oxide (NO) and total protein, albumin, globulin levels in rabbits. MATERIAL AND METHODS: Twenty healthy New Zealand rabbits were allocated to 2 equal groups. Group I received 0.5 mg/kg and Group II received 1 mg/kg of ivermectin via subcutaneous injection. Blood samples were collected before the experiment, at 24 and 120 hours following the treatments. RESULTS: Ivermectin at therapeutic doses increased plasma NO level at 24 h while decreased TAC at 120 h and did not alter other parameters. CONCLUSION: These findings may suggest that ivermectin is a safe antiparasitic drug for mammals but to less extent, it may have an effect on the oxidant/antioxidant balance.

Serum sialic acid and oxidative stress parameters changes in cattle with leptospirosis.

This study was designed to disclose some indicators of oxidative stress and inflammation in natural cases of bovine leptospirosis. For this purpose, 12 bulls exhibiting clinical signs of leptospirosis and 10 healthy bulls were used. Animals were subjected to thorough clinical examination and the clinical signs were recorded. All animals were blood sampled in order to determine serum total sialic acid (TSA), lipid bound sialic acid (LBSA), malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), uric acid (UA), total protein (TP), albumin and glucose. Urine samples were collected from each animal and examined under dark-field microscope to observe spirochetes. Diseased animals exhibited clinical signs suggesting leptospirosis and the diagnosis was supported by positive dark-field microscope examination. Mean TSA (mmol/L), LBSA (mmol/L), TP (g/dl), albumin (g/dl), glucose (mg/dl), MDA (micromol/L), GSH (mg/dl), NO (nmol/ml), and UA (mg/L) levels were 1.63 +/- 0.02, 0.40 +/- 0.10, 7.18 +/- 0.24, 3.23 +/- 0.5, 64.96 +/- 1.88, 5.71 +/- 0.11, 78.68 +/- 0.72, 7.94 +/- 0.34, and 8.75 +/- 0.41 in healthy bulls, and 2.50 +/- 0.05, 0.70 +/- 0.2, 9.27 +/- 0.17, 2.55 +/- 0.62, 107.93 +/- 2.52, 8.82 +/- 0.14, 47.85 +/- 1.85, 14.57 +/- 0.63 and 15.85 +/- 0.80 in leptospirosis cases, respectively. The differences between the two groups were statistically significant (P < 0.001). Increased TSA, LBSA, MDA, NO, UA, TP, glucose and decreased GSH and albumin concentrations were suggestive of inflammation and oxidative stress in diseased bulls. The results obtained may suggest that oxidative damage along with other mechanisms might have taken part in the pathogenesis of bovine leptospirosis and further detailed studies are needed to fully understand the mechanism(s) of the disease.

Protective effect of L-carnitine against oxidative damage caused by experimental chronic aflatoxicosis in quail (Coturnix coturnix).

This study was designed to evaluate the effect of L-carnitine supplementation on the plasma malondialdehyde (MDA) and whole blood reduced glutathione (GSH) concentrations in experimentally-induced chronic aflatoxicosis in quails. For this purpose, a total of 80 quails up to 8 weeks old were divided into four equal groups. Group I served as control, Group II was given L-carnitine at the dose of 200 mg/litre in the drinking water for 60 days, Group III was given 60 microg total aflatoxin/kg diet for 60 days, and Group IV was given both 60 microg total aflatoxin/kg diet and 200 mg L-carnitine/litre in the drinking water for 60 days. Aflatoxin treatment caused a significant increase in plasma MDA and a significant decrease in blood GSH concentrations. On the other hand, there was a significant decrease in plasma MDA and a significant increase in whole blood GSH in the L-carnitine-supplemented group. The present study demonstrated that L-carnitine brought about the inhibition of lipid peroxidation by enhancing antioxidant capacity in quails with chronic aflatoxicosis.