Giovanna Calzaretti

Molecular inhibitory mechanisms of antioxidant enzymes in rat liver and kidney by cadmium

Catalase, Mn-superoxide dismutase (MnSOD) and Cu,Zn-superoxide dismutase (CuZnSOD) activities were studied in rat liver and kidney 6-48 h after CdCl(2) intraperitoneal administration or 10-30 days daily oral CdCl(2) intake in drinking water. This approach provided some indications as to the sensitivity of each enzyme to cadmium toxicity. These experiments showed that the formation of thiobarbituric acid reactive substance (TBARS) did not strictly depend on how well the antioxidant enzyme worked. From in vitro experiments it appeared that TBARS removal by vitamin E did not restore the three enzyme activities at all. As for cadmiums inhibitory mechanism on catalase activity, our data, obtained in the pH range 6.0-8.0, are a preliminary indication that the negative effect of this metal is probably due to imidazole residue binding of His-74 which is essential in the decomposition of hydrogen peroxide. Cadmium inhibition of liver mitochondrial MnSOD activity was completely removed by Mn(2+) ions, suggesting that the reducing effect on this enzyme is probably due to the substitution of cadmium for manganese. We also observed the antioxidant capacity of Mn(2+) ions, since they were able to normalize the increased TBARS levels occurring when liver mitochondria were exposed to cadmium. The reduced activity of CuZnSOD does not seem to be due to the replacement of Zn by Cd, nor to the peroxides formed. As this enzyme activity was almost completely recovered after 48 h, we hypothesize that the momentary inhibition is imputable to a cadmium/enzyme interaction. This causes some perturbation in the enzyme topography which is critical for its catalytic activity. The pathological implications linked to antioxidant enzyme disorders induced by cadmium toxicity are discussed.

Antioxidant effect of hydroxytyrosol (DPE) and Mn2+ in liver of cadmium-intoxicated rats.

Liver TBARS formation in cadmium-intoxicated rats was completely reduced by administering a low amount of MnCl(2) (2 mg/kg b.w.) 1 h before intoxication. A similar antioxidant effect was first shown by hydroxytyrosol (2-(3,4-dihydroxyphenyl)ethanol, (DPE), a phenolic compound present in olive oil, given twice to rats (9 mg/kg b.w.) after cadmium administration. The antioxidant properties shown in vivo by both Mn(2+) and DPE were also active in vitro when rat liver microsomes were subjected to lipid peroxidation by cadmium or other prooxidant systems. The increase in liver glutathione concentrations occurring in cadmium-intoxicated rats, was also found, for the first time, 24 h after MnCl(2) administration. Unlike cadmium intoxication, which caused a higher formation of both glutathione and TBARS, Mn(2+) induced glutathione synthesis without any TBARS formation. The same situation was also observed when cadmium plus Mn(2+) or cadmium plus DPE was given to rats. Our data show that: (a). both DPE and low Mn(2+) concentrations may have an antioxidant effect in the livers of cadmium-intoxicated rats and (b). Mn(2+), like cadmium, induces liver glutathione synthesis and this effect is probably independent of TBARS formation.

The Nrf2 transcription factor contributes to the induction of alpha-class GST isoenzymes in liver of acute cadmium or manganese intoxicated rats: comparison with the toxic effect on NAD(P)H:quinone reductase.

In rat liver, in addition to their intrinsic transferase activity, alpha-class GSTs have Se-independent glutathione peroxidase activity toward fatty acid hydroperoxides, cumene hydroperoxide and phospholipids hydroperoxides but not toward H(2)O(2.) We have previously shown that hepatic GST activity by these isoenzymes is significantly increased 24h after cadmium or manganese administration (Casalino et al., 2004). Here it is reported that Se-independent glutathione peroxidase activity by alpha-class GSTs is also stimulated in the liver of intoxicated rats. The stimulation is associated with a higher level of alpha-class GST proteins, whose induction is blocked by actinomycin D co-administration. The observed Se-independent glutathione peroxidase activity is due to alpha-class GST isoenzymes, as indicated by the studies with diethyldithiocarbamate which, at any concentration, equally inhibits both GST and Se-independent glutathione peroxidase and is an uncompetitive inhibitor of both enzymes. As for liver Se-GSPx, it is not at all affected under these toxic conditions. For comparison, we have evaluated the status of another important antioxidant enzyme, NAD(P)H:quinone reductase, 24h after cadmium or manganese administration. NQO1 too results strongly stimulated in the liver of the intoxicated rats. In these animals, a higher expression of Nrf2 protein is observed, actively translocated from the cytoplasm to the nucleus. The results with the transcription inhibitor, actinomycin D, and the effects on Nrf2 protein are the first clear indication that acute manganese intoxication, similarly to that of cadmium and other heavy metals, increases both the hepatic level of Nrf2 and its transfer from the cytoplasm to the nucleus where it actively regulates the induction of phase II enzymes.

Antioxidant role of hydroxytyrosol on oxidative stress in cadmium-intoxicated rats: different effect in spleen and testes

Abstract Hydroxytyrosol (2-(3,4dihydroxyphenyl)ethanol, (DPE), a phenolic compound present in olive oil, is known to have antioxidant properties. The aim of this study was to investigate the effect of DPE on oxidative stress induced by cadmium injections (CdCl2 2.5 mg/kg body weight) in spleen and testes of adult male rats. Oxidative stress was evaluated by measuring lipid peroxidation by thiobarbituric acid reactive substances (TBARS) as well as superoxide dismutase (SOD) and catalase (CAT) activities in cytosol and mitochondria. We found that in spleen no TBARS formation was detected following CdCl2 injections; however, DPE induces decrease in TBARS level in treated and untreated rats. On the contrary, we observed that DPE showed no effect on cadmium-induced lipid peroxidation in testes. Cytosolic activities of SOD and CAT decreased significantly only in spleen, where DPE restores the values to the control levels. Noteworthy, mitochondrial activities of SOD and CAT were strongly reduced by cadmium treatment both in spleen and testes, and DPE was not be able to restore their activity. Overall, the results from this study indicated that the DPE has different antioxidant efficiency in spleen and testis of cadmium intoxicated rats.

Is meat quality from Longissimus lumborum samples correlated with other cuts in horse meat

The present work aims to investigate if the variation of each parameter in Longissimus lumborum muscle could correspond to the same or to a similar variation of the parameter in the other muscles. The work presents results of Pearsons correlations between Longissimus lumborum samples and other muscle samples, such as Biceps femoris, Rectus femoris, Semimembranosus, Supraspinatus and Semitendinosus in horse meat. A total of 27 male IHDH (Italian Heavy Draught Horse) breed foals were employed. They were slaughtered at 11 months of age and the above-mentioned muscles were sampled. The Longissimus lumborum muscle showed to be representative of other muscles and of the whole carcass for some chemical parameters (moisture, protein and ash) and for some fatty acids profile patterns such as C12:0, C14:0, total monounsaturated fatty acid and polyunsaturated fatty acid, but poor correlations were recorded for intramuscular fat concentration, rheological and colorimetric parameters. Although almost all the qualitative parameters in meat are affected by the anatomical site and by the muscle, the Longissimus lumborum is often not representative in horse meat with regard to modifications of this parameters.

Equid milk production: evaluation of Martina Franca jennies and IHDH mares by Wood’s model application

The present work aims to evaluate milk production aptitude of two equid species: horse and donkey. The trial was conducted on the Italian Heavy Draught breed horse (IHDH) and on the Martina Franca breed donkey. Data were collected from 23 multiparous nursing IHDH mares aged from 6 to 10 years, with an average bodyweight (BW) (mean ± s.d.) of 822.3 ± 61.8 kg and from 28 multiparous nursing donkeys of Martina Franca breed aged from 7 to 12 years, with an average BW (mean ± s.d.) of 389.5 ± 21.2 kg. Milk yield was recorded on 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180 days in milk (DIM). At each milk yield evaluation day, a milk sample was collected and its composition was analysed. All data were normalised according metabolic weight (MBW) of animals, so to make comparable results of the two considered species. Wood’s lactation model was used to describe milk, fat, protein and lactose yield. Peak lactation was reached on DIM 69 in IHDH horse and on DIM 48 in Martina Franca donkey with a milk production of 10.693 kg/100 kg MBW (R2 = 0.9139) and 5.264 kg/100 kg MBW (R2 = 0.9428), respectively. Persistency index of milk lactation curve was higher in Martina Franca donkey then in IHDH mares (7.0338 vs 6.2672). IHDH mares showed higher fat and protein production. Lactose curves showed a similar trend in both the species although IHDH’s curve was characterised by higher values. Data reported in the present work underline that both breeds considered are characterised by good milk production aptitude. Moreover, high R2 values obtained applying Wood’s model to milk, fat, protein and lactose production, calculated on the metabolic bodyweight basis, are indices of goodness of model fit.

An assessment of sire-breed effects on carcass and meat quality traits of lambs at the ages of 40 and 100 days from Comisana ewes crossed with Suffolk or Bergamasca rams

The aim was to compare lambs at two different ages at slaughter (40 vs 100 days) and three breeds or crossbreeds including an Italian dairy breed (Comisana (Com)) and its crosses with the two meat breeds of Bergamasca (Ber × Com) and Suffolk (Suf × Com) with 20 male lambs per age per breed group. At both slaughter ages, crossbreeds were more productive, with higher liveweight (P = 0.02), carcass weight (P = 0.03) and dressing percentage (P = 0.04) than the Com group. Meat from the younger lambs showed lower C10:0, C14:0 and C22:0 (P < 0.05) and higher C18:1 (P < 0.01) concentrations, resulting in higher monounsaturated fatty acid (P < 0.01) and lower saturated fatty acid (P < 0.01) content. Moreover, their meat has lower redness (a*), yellowness (b*) and chroma (C*) values (P < 0.01). Crossbreeding dairy breed ewes with sires of high meat production breeds improves liveweight and carcass weight. Meat from younger lambs had lower intramuscular fat content and higher concentrations of polyunsaturated fatty acid.

Survey on basal blood plasma catecholamine concentrations in Martina Franca donkey (Equus asinus)

BACKGROUND Catecholamines are among the most frequently investigated parameters for studying sympathoadrenal activity in response to stress conditions. OBJECTIVES To evaluate basal plasma concentrations of catecholamines (adrenaline, noradrenaline and dopamine) in healthy donkeys. STUDY DESIGN Cross-sectional study. METHODS Catecholamine concentrations from 440 Martina Franca donkeys were determined: 269 females and 171 entire males, aged from 4 months to 24 years. Animals were subdivided into four age categories: under 12 months old (64 males and 54 females), from 13 to 36 months (56 males and 75 females), from 37 to 120 months (49 males and 80 females) and over 120 months (24 males and 38 females). Indwelling jugular catheters were inserted at least 12 h before drawing blood. The data set was subjected to analysis of variance considering age, sex and the two-way interaction between them as independent variables. Pearsons correlation coefficients between the three catecholamines were evaluated. RESULTS Confidence intervals (CI) for noradrenaline concentration ranged between 239.98 and 255.07 ng/L (mean 247.52 ng/L), for adrenaline between 129.27 and 137.90 ng/L (mean 133.59 ng/L), dopamine concentrations between 149.62 and 160.80 ng/L (mean 155.21 ng/L) and noradrenaline/adrenaline ratio between 1.91 and 2.05 (mean 1.98). Catecholamine plasma concentrations were not influenced by sex. Donkeys older than 37 months had lower adrenaline and noradrenaline plasma concentrations (P<0.001) and higher noradrenaline/adrenaline ratios (P<0.01) than younger animals. MAIN LIMITATIONS Indwelling catheters and blood drawing procedures may have influenced catecholamine levels. CONCLUSIONS Catecholamine concentrations were established within a large group of healthy Martina Franca donkeys.

Preliminary approach to heat treatment traceability in donkey milk

Mauritania, with its geographical position, is a Sahelian country whose climatic and socio-economic conditions make it a dromedary breeding country par excellence. The camelin population is estimated at 1.4 million heads for a population close to 3 million inhabitants. Dromedaries play an important role in the Mauritanian economy through their supply of meat and milk, transport and other services. With the urbanization and the population growth in the country are accompanied by an increase in demand for milk and dairy products. In recent years, we have seen the growth of camelin breeding near large cities and urban centers. This developed peri-urban camelin system is for the promotion of milk which is highly prized by Mauritanians. During the night, consumers go to the outlets to buy fresh camel milk sold on site. These points of sale are easily identifiable and are generally located on the roads of urban centers. In big cities such as Nouakchott and its periphery, there is a large estimated number of 2000 to 2,500 head of dromedaries, particularly for dairy production. In dromedaries, two milking per day are practiced after stimulation of the camel by the camel. The daily production is of the order of 8 to 10 liters at the rate of 4 to 5 liters / milking. Dairy females raised in these urban centers are selected and selected from the best dairy in pastoral areas.Enterococci are commensal organisms of human and animals, and may cause diseases in particular conditions. Several virulence factors are responsible in the production of diseases. The aim of this study was to isolate enterococci from fish and to determine virulence factors of the isolates. A total of 26 (13%) Enterococcus faecalis strains were isolated from live, moribund and dead fish collected from fish farms in Aegian Region. Cytolysin and gelatinase activities and aggregation substance production of these strains were examined.Cytolysin production was not detected in any of E. faecalis strains. Of 26 strains tested, 27% was found to produce aggregation substance. Gelatinase activity was found in 11.5% of strains. The presence of strains with important virulence factors in enterococci from fish was established. It was suggested that these strains have the potential of producing disease in human and animals.Yumurtaci tavuklarda bitkilerin ve bitkisel urunlerin kullaniminin performans ve taze yumurta kalitesine etkileri uzerine calismalar yapilmis olmasina ragmen depolama kalitesine uzerine etkileri hakkinda oldukca sinirli bilgi mevcuttur. Calisma; Mentha Piperitaekstraktinin ve ozsuyunun sirasiyla yem ve su katkisi olarak kullanilmasinin farkli depolama surelerinde yumurta kalitesine etkisini arastirmak amaciyla planlanmistir. Calismanin hayvan materyalini 252 Babcock irki yumurta tavugu teskil etmistir. Hayvanlar 7 ana gruba ve devaminda 4 alt gruba ayrilmis ve her alt grup 9 hayvandan olusmustur. A Grubu rasyonunda herhangi bir katki kullanilmamis ve kontrol grubu olarak belirlenmistir. B, C ve D gruplari sirasiyla nane ekstraktini 50, 100 ve 200 mg/kg dozlarinda yem katkisi olarak; E, F ve G gruplari ise ayni dozlarda nane ozsuyunu icme suyu katkisi olarak tuketmislerdir. Calisma sonunda (56 gun) 252 yumurta (her gruptan 36 yumurta olmak uzere) rastgele olarak toplanmistir. 84 adet yumurta depolama oncesi analiz edilmis, diger ornekler +4°C’de depolanmistir. Depolanan yumurtalardan 84 tanesinin analizleri depolamanin 15 gununde, geri kalan 84 yumurtanin ise analizleri depolamanin 30 gununde yapilmistir. Calisma sonucunda yumurta kalite parametrelerinden yumurta kabugu kirilma mukavemeti, yumurta sarisi rengi, haugh birimi ve yumurta agirligi, farkli depolama surelerinde gruplar arasinda istatistiksel farklilik (P>0.05) gostermemistir.