Houda Hamed

Analysis of Raw Milk Quality at Reception and During Cold Storage: Combined Effects of Somatic Cell Counts and Psychrotrophic Bacteria on Lipolysis

The objective of the article was to analyze the influence of psychrotrophic bacteria counts (PBCs) and somatic cell counts (SCCs) on the extent of lipolysis in bulk samples of cows milk at reception and during cold storage. Samples of milk were analyzed on the day of sampling and subsequently during cold storage. The acidity, fat, density, chloride content, electrical conductivity (EC), bulk milk SCCs (BMSCC), and PBC values were analyzed on the day of sampling and the levels of acidity, EC, SCC, and PBC were analyzed during cold storage at 4 °C for 72 h. The SCC value 869 × 10(3) mL(-1) was higher than the recommended threshold. Lipolysis level at sampling day was related more closely with SCC than with PBC. There was no significant correlation between milk acidity and PBC among others parameters, while the milk mean density was only significant (P < 0.01) correlated with the fat content. The EC and chloride content were consistently correlated (P < 0.001) with BMSCC that allowed them to be used as indicators of mammary gland infection. The milk acidity, EC, PBC, and lipolysis levels increased in relation to the storage time at 4 °C. The lipolysis level during storage was in closer relation to the SCC, but not relation to the PBC. Effects of SCC and PBC on lipolysis decreased throughout the chilling period. It was concluded that initial lipolysis level and intrinsic milk lipoprotein lipase appear more effective than SCC and PBC on the development of lipolysis during storage.

Total and differential bulk cow milk somatic cell counts and their relation with antioxidant factors

In the present study, the relationship between total bulk milk somatic cell counts (BMSCC), differential BMSCC (macrophage, lymphocyte, and polymorphonuclear leukocytes), and antioxidant enzymes was investigated. Forty-three samples of bulk milk were selected randomly from eight dairy farms in the region of Sfax (Tunisia) in winter, from November 2005 to February 2006. Bulk milk samples were analyzed for antioxidant enzymes such as catalase, SOD and GSHPx activity and differential SCC. After that, milks were allotted according to their total SCC to: group 1, bulk milk with SCC below 1000x10(3) ml(-1); group 2, bulk milk with SCC from 1000x10(3) to 1500x10(3) ml(-1); group 3, bulk milk with SCC above 1500x10(3) ml(-1). BMSCC levels ranged from 400x10(3) to nearly 4000x10(3) ml(-1). Lymphocytes were the predominant cell type in all groups, but their proportion declined with the total BMSCC. Catalase and GSHPx activities were found to be significantly (P<0.001) correlated with total BMSCC and with the PMN population. In contrast, a weak correlation between the activity of the SOD and total or differential bulk milk somatic cells was observed. It has been suggested that milk cells, especially PMN, could generate a situation of oxidative stress in the mammary gland. Specifically, hydrogen peroxide and hydroxyl radicals were probably the most important reactive oxygen metabolites released by PMN.

Evaluation of Tunisian milk quality in dairy herds: Inter-relationship between chemical, physical and hygienic criteria

The objective of this paper was to evaluate the global milk quality in Tunisian dairy herds. Samples of milk were analyzed for chemical, physical and hygienic parameters. Milk total solids, fat content and density were consistently correlated and one of them can be used as a chemical indicator of milk quality. The somatic cell count value of 689 × 10(3) /mL was higher than the recommended threshold. All milk samples were positive for the major pathogen Staphylococcus aureus. These hygienic parameters were related more closely with chloride content, minerals and electrical conductivity, which allows them to be used as indicators of mammary gland infection. It was concluded that milk producers have at hand rapid and easy tools for assessing the overall quality of milk.

Effects of Spirulina platensis on lipid peroxidation, antioxidant defenses, and tissue damage in kidney of alloxan-induced diabetic rats

Chronic hyperglycemia in diabetes causes free radicals overproduction, which contributes to the development of diabetic nephropathy. In modern medicine, no satisfactory therapy is available to cure diabetes mellitus. In that context, we investigated the potential therapeutic action of spirulina-enriched diet on renal impairment and oxidative stress in diabetic rats. Diabetes was induced by a single subcutaneous injection of alloxan (120 mg·kg-1) in rats. Following alloxan treatment, male Wistar rats were fed daily with 5% spirulina-enriched diet or treated with insulin (0.5 IU·rat-1) for 3 weeks. Diabetes was associated with hyperglycemia, increase in renal oxidative parameters (lipid peroxidation, thiobarbituric-acid reactive substances, protein carbonyl and advanced oxidation protein products levels, changes in antioxidant enzyme activities), and nephropathology markers. The renal injury induced by alloxan was confirmed by histological study of the diabetic rat kidney. Treatment with spirulina or insulin significantly ameliorated renal dysfunction by reducing oxidative stress, while rats recovered normal kidney histology. Overall, this study indicates that spirulina is efficient in inhibiting hyperglycemia and oxidative stress induced by diabetes, and suggests that the administration of this alga may be helpful in the prevention of diabetic complications. This amelioration was even more pronounced than that caused by insulin injection.

Beneficial effects of fermented camel milk by lactococcus lactis subsp cremoris on cardiotoxicity induced by carbon tetrachloride in mice

Carbon tetrachloride (CCl4) is a xenobiotic present in the environment, can cause harmful effects on human health. In the present study, we attempted to elucidate the cardiopreventive potential of the fermented camel milk by lactococcus lactis subsp cremoris (FCM-LLC) against the toxic effects of acute exposure to CCl4 on heart tissue of mice. Twenty-eight mices were divided into four groups of seven each: group (C) served as control; group (FCM-LLC) received only 100mgL of FCM-LLC/kg body weight daily for 15days; group (CCl4) was administered by a single dose of CCl4 (10mL/kg in 0.3% olive oil, i.p) at day 14 and group (FCM-LLC+CCl4) pretreated with FCM-LLC and received a single dose of CCl4 on day 14. The exposure to a single dose of CCl4 caused cardiotoxicity expressed by an increase in lipid peroxidation (TBARS), protein carbonyls (PC) levels and in antioxidant markers (superoxide dismutase (SOD), catalase (CAT), gluthathione peroxidase (GPx), glutathione (GSH) and Vitamin C levels) in the CCl4-treated group when compared with the untreated group. Furthermore, treatment with CCl4 significantly elevated the cardiac toxicity markers while increasing of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase MB (CKMB) and Troponin I activities. The pre-treatment of experimental mices with FCM-LLC has allowed an improvement through lowering oxidative stress and attenuating cardiac toxicity. These modifications were further evident through histopathological aspects of the heart. Overall, the present data provide evidence of the beneficial effects of fermented camel milk by lactococcus lactis subsp creemoris clearly revealed through the reduction of the CCl4 induced heart oxidative damages.

Immunomodulatory and antioxidant protective effect of Sarcocornia perennis L. (swampfire) in lead intoxicated rat

Abstract Lead (Pb) is a very toxic metal present in the environment, causing disturbances of several functions. Preventive or curative effects of halophytic plants against these disorders may be a promising and safe therapeutic strategy. Thus, this study was designed to evaluate in vivo immunomodulatory and antioxidant effects of Sarcocornia perennis extract (Sp) against lead toxicity in rats. Groups of six animals each were treated with plant extract (via food), 6 g/L lead acetate (via drinking water) or a combination of both. At the end of the three-week period, rat exposure to lead caused reduction of liver weight but an increase of that of kidney. Moreover, lead intoxication-induced oxidative stress manifested by significant increases of inflammatory cytokines (except IL-10) and lipid peroxidation (TBARS), compared with the control group. Meanwhile, interleukin-10 (IL-10) and glutathione levels (GSH), as well as antioxidant activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were decreased. Considering liver and renal markers, lead treatment induced a significant increase in the activities of aminotransferases (AST, ALT), and in the levels of urea, creatinine and phosphorous, whereas total plasma protein, albumin and calcium levels were significantly decreased. S. perennis extract alone did not induce any significant changes in hepatic or renal markers, whereas the antioxidant markers were significantly increased. S. perennis supplementation significantly reduced the lead-induced elevation of serum IL-1ß, IL-6, TNF-α, IFN-γ and TBARS but increased the IL-10 and antioxidant enzyme activities. Overall, plant components ameliorated hepatorenal damages caused by lead.

Cardiopreventive effects of camel milk against carbon tetrachloride induced oxidative stress, biochemical and histological alterations in mice

Abstract The present study was designed to examine the preventive effects of camel milk (CM) against the toxic effects of acute exposure to carbon tetrachloride (CCl4) on the heart tissue of mice. Administration of a single dose of CCl4 caused cardio toxicity as monitored by an increase in lipid peroxidation (thiobarbituric acid reactive substances), protein carbonyl level and antioxidant markers (superoxide dismutase, catalase, glutathione peroxidase, glutathione and vitamin C) in the heart tissue. Moreover, CCl4 caused a distinguished rise of plasma aspartate aminotransferase, lactate dehydrogenase, troponin I, and creatine kinase activities. Furthermore, CM ameliorated biochemical and histological parameters as compared to CCl4-treated group. Overall, this study indicates that CM is efficient in inhibiting oxidative stress induced by CCl4 and suggests that the administration of this milk may be helpful in the prevention of cardio-toxicity complications.

Modulatory Effects of Rosemary Leaves Aqueous Extraction against oxidative stress and related damages in experimental model of CCl4-induced cardiac toxicity in mice

Rosmarinus officialis L., Lamiaceae, has been traditionally used in Tunisia to treat several diseases. The aim of the present study is to analyze the cardiopreventive effect of Aqueous Extract of Rosemary (Rosmarinus officinalis) Leaves (AERL) against oxidative stress induced by carbon tetrachloride in experimental mice. The current study was performed on female Wistar mice divided into four groups of seven animals each. Cardiotoxity was induced by a single intraperitoneal injection of CCl4 (10ml/kg in 0.3 % olive oil) in mice which were gavaged daily with 100 mg of AERL for 15 days. CCl4 exposure caused a disturbance of cardiac markers such as LDH, γGT, CK, CKMB and Troponin I. Moreover, cardiotoxicity indices such as TBARS and protein carbonyls levels exhibited remarkable increases, while antioxidant enzymes activities (CAT, SOD and GPx) and GSH level decreased when compared with control group. Besides, the triglycerides, the total cholesterol, and low-density lipoprotein cholesterol levels and the transaminases activities (ALT, AST and ALP) decreased. The pretreatment with AERL can also significantly prevent the heart damage through the correction of electrolytes (Na+, K+, Cl- and Ca2+) and lipid parameters, leading to a good defense against cardiotoxicity as well as good antioxidant status. The histological analysis of cardiac tissues further established the positive effect of AERL. These findings could be due to the high phenolic content and to important antioxidant capacity of Rosmarinus officinalis. Overall, this study suggests that the administration of AERL displays high potential to quench free radicals and alleviates CCl4-induced cardiotoxicity in mice.

Effects of Zeolite supplementation on dairy cow production and ruminal parameters – a review

Abstract In recent years, the use of both natural and synthetic zeolites in livestock feeds fed to lactating cows has increased, mainly to improve their performance, health, and to protect against mycotoxins intoxication. Data of scientific literature were compiled to analyze the effects of the incorporation of non-nutritional adsorbent zeolite on production performance and ruminal environment parameters of lactating cows. At moderate levels (200–400 g/cow/day), milk yield was increased by zeolite. Milk fat and protein contents and DMI were not altered and all ruminal parameters were improved: acetate was enhanced, propionate was reduced and consequently, acetate to propionate ratio was increased. The rumen pH was increased and rumen ammonia nitrogen was reduced. When the level of zeolite exceeded 400 g/d/cow, all production and ruminal parameters were negatively altered. These data suggest that zeolite level in the diet has a significant effect on the response of dairy production and ruminal environment characteristics.