Khaled Bellassoued

Impact of proline application on cadmium accumulation, mineral nutrition and enzymatic antioxidant defense system of Olea europaea L. cv Chemlali exposed to cadmium stress

Proline plays an important role in plant response to various environmental stresses. However, its involvement in mitigation of heavy metal stress in plants remains elusive. In this study, we examined the effectiveness of exogenous proline (10 and 20 mM) in alleviating cadmium induced inhibitory effects in young olive plants (Olea europaea L. cv. Chemlali) exposed to two Cd levels (10 and 30 mg CdCl2 kg(-1) soil). The Cd treatment induced substantial accumulation of Cd in both root and leaf tissues and a decrease in gas exchange, photosynthetic pigments contents, uptake of essential elements (Ca, Mg and K) and plant biomass. Furthermore, an elevation of antioxidant enzymes activities (superoxide dismutase, catalase, glutathione peroxydase) and proline content in association with relatively high amounts of hydrogen peroxide, thiobarbituric acid reactive substances and electrolyte leakage were observed. Interestingly, the application of exogenous proline alleviated the oxidative damage induced by Cd accumulation. In fact, Cd-stressed olive plants treated with proline showed an increase of antioxidant enzymes activities, photosynthetic activity, nutritional status, plant growth and oil content of olive fruit. Generally, it seems that proline supplementation alleviated the deleterious effects of young olive plants exposed to Cd stress.

Protective effect of kombucha on rats fed a hypercholesterolemic diet is mediated by its antioxidant activity

Abstract Context: Kombucha (KT) is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature. Objective: The present study investigates the effects of Camellia sinensis (GT) Linn. (Theaceae) and KT, two natural drinks, on cholesterol and antioxidant status using a hypercholesterolemia rat model. Materials and methods: The present study compared the free-radical scavenging abilities and polyphenol levels of GT and KT. Wistar rats fed cholesterol-rich diets were given KT or GT (5 mL/kg body weight per day, po) for 16 weeks, then fasted overnight and sacrificed. The plasma lipid levels, thiobarbituric acid reactive substances (TBARS) and aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transpeptidase (GGT) serum levels, antioxidant activities of superoxide dismutase (SOD) and catalase (CAT), and creatinine and urea rats were examined. Results: KT had a phenolic compound of 955 ± 0.75 mg GAE/g) followed, by GT (788.92 ± 0.02 mg GAE/g). The free radical scavenging activity of KT was higher than GT. Compared with GT, KT induced lowered serum levels of TC, TG, VLDL-C, and LDL-C by 26, 27, 28, and 36%, respectively, and increased the serum level of high-density lipoprotein cholesterol (HDL-C). KT induced a 55% decrease of TBARS level in liver and 44% in kidney, compared with those of rats fed a cholesterol-rich diet alone. Moreover, CAT and SOD activities were reduced by 29 and 33%, respectively, in liver and 31 and 35%, respectively, in kidney, after oral administration of KT, compared with those of HCD-fed rats. Conclusion: The findings revealed that KT administration induced attractive curative effects on hypercholesterolemic, particularly in terms of liver–kidney functions in rats. Its effect on humans needs to be studied further.

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.

Protective effect of Dunaliella sp., lipid extract rich in polyunsaturated fatty acids, on hepatic and renal toxicity induced by nickel in rats

Abstract Aims: The present study was undertaken to investigate the protective effect of lipid extract of Dunaliella sp. (LE) rich in polyunsaturated fatty acids (PUFA), against oxidative stress induced by nickel in experimental rats. Methods: Our investigation evaluated the antioxidant activity of LE using both DPPH and NBT assays. Twenty female albino Wistar rats, randomly allocated into four experimental groups, namely (C): control, (Nit): nickel-treated rats with 5 mg/kg/d of NiCl2 during 30 days, (LEa): lipid extract-administered rats with 5  mg/kg BW/d during 30 days and (Nit + LEa): rats treated with Ni and LE-administered during 30 days. Results: The in vitro antioxidant activity demonstrated that LE presents an important antioxidant potential. In vivo, the (Nit + LEa) cotreatment decreased the level of malondialdehyde and restored the antioxidant enzyme activities (superoxide dismutase, catalase and glutathione peroxidase) in livers and kidneys in comparison with those treated with Ni only. LE administration to rats treated with Ni also ameliorated biochemical and histological parameters as compared to only Ni-treated group. LE of Dunaliella sp., rich in polyunsaturated fatty acids showed a significant hepato- and reno-protective effect against metal-induced toxicity. Conclusion: LE of Dunaliella sp., rich in PUFA has been proven to be effective in protection against Ni-induced toxicity.

Hepatotoxicity in rats induced by the poisonous dreamfish (Sarpa salpa)

Abstract Aims: The present study was aimed to assess the cytotoxic effects of not-yet identified compounds present in organ extracts of Sarpa salpa, collected in autumn, the period with a peak in health problems. Methods: The toxicity was assessed by mouse bioassay of extract of the fish’s organs. Wistar rats received daily extracts of different organs of S. salpa by gastric gavage for 7 d (0.3 ml of extract/100 g body weight, BW). The dose of tissue extracts of viscera, liver, brain and flesh of S. salpa administered to rats were as follows: 17.2, 31.3, 205, 266 mg/100g BW, respectively. No deaths occurred during the period of treatment. Results: The lethal dose (LD50%) determined for the crude ciguatoxin (neurotoxins) extracts of viscera, liver, brain and flesh of S. salpa were as follows: 1.2, 2.2, 14.4, 18.6 g/kg mouse, respectively. Changes in locomotor activity during the first 2 h and failure breathing and no evident signs of gastrointestinal problems were recorded. We observed: (1) Induction of oxidative stress, indicated by an increase in lipid peroxidation (TBARS) in groups that received extracts of liver (+490%) or viscera (+592%). Accompanied by a significant decrease in antioxidant enzyme activities (SOD, CAT, GPx) in liver tissue by 15%, 17%, 18% (LT: animals receiving liver extracts) and by 19%, 22%, 22% (VT: animals receiving viscera extracts), respectively. In contrast the administration of extracts of flesh and brain induced an increase in antioxidant enzyme activities (SOD, CAT, GPx) in liver tissue by 15%, 19%, 15% (FT: flesh extract) and 18%, 55%, 55% (BT: brain extract), respectively; (2) A significant increase in total metallothionein levels in liver tissue was recorded in (FT), (BT), (LT) and (VT) by 55%, 88%, 255% and 277%, respectively, (3) The histological findings confirmed the biochemical results. Conclusions: Liver and especially visceral part of S. salpa presented toxicity, which clearly indicates the danger of using this fish as food.