Yassine Chtourou

Evaluation of the antioxidant, anti-inflammatory and hepatoprotective properties of vanillin in carbon tetrachloride-treated rats.

The antioxidant and anti-inflammatory effects of vanillin are considered as important forces in the protection against liver injury and fibrosis. This study investigated the protective effects of vanillin against carbon tetrachoride (CCl(4))-induced hepatotoxicity in rat. Pretreatment with vanillin prior the administration of CCl(4) significantly prevented the decrease of protein synthesis and the increase in plasma alanine (ALT) and aspartate (AST) aminotransferases. Furthermore, it inhibited hepatic lipid peroxidation (MDA) and protein carbonyl (PCO) formation and attenuated the (CCl(4))-mediated depletion of antioxidant enzyme catalase and superoxide dismutase (SOD) activities and glutathione level (GSH) in the liver. In addition, vanillin markedly attenuated the expression levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) and prevented CCl(4)-induced hepatic cell alteration and necrosis, as indicated by liver histopathology. These findings suggest that the antioxidant and anti-inflammatory effects of vanillin against CCl(4)-induced acute liver injury may involve its ability to block CCl(4)-generated free radicals.

Naringenin reduces cholesterol-induced hepatic inflammation in rats by modulating matrix metalloproteinases-2, 9 via inhibition of nuclear factor κB pathway.

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of hepatic abnormalities that extends from isolated steatosis to non-alcoholic steatohepatitis (NASH) and steatofibrosis. NASH is the progressive form of the disease that can lead to fibrosis, cirrhosis and hepatocellular carcinoma. Naringenin (NGEN), a healthful food, increases resistance to oxidative stress, inflammation and protects against multiple organ injury in various animal models. However, specific mechanisms responsible for such effects are poorly understood. Thus, this study investigates the effect of treatment with NGEN (50mg/kg) on oxidative events and the molecular mechanisms underlying inflammatory changes triggered in the rat liver by a high cholesterol diet for 90 days. NGEN significantly decreased the plasma fatty acid composition, the hepatic pro-inflammatory mediators and the expression of relevant genes including tumor necrosis factor-α, interlukin-6, interleukin-1β, inducible nitric oxide synthase and matrix metalloproteinases (MMP-2, 9), EGF-like module-containing mucin-like hormone receptor-like 1 (macrophage F4/80-specific gene); which suggests a reduced macrophage infiltration, and inhibited oxidative stress related biomarker levels at the end point of the experiment. Mechanistically, studies showed that NGEN markedly reduced lipid and protein oxidations, recruited the anti-oxidative defense system and promoted extracellular matrix degradation by modulating the levels of necrotic inflammation.

Protective role of naringin against cisplatin induced oxidative stress, inflammatory response and apoptosis in rat striatum via suppressing ROS-mediated NF-κB and P53 signaling pathways

Cisplatin (Cis) is an effective chemotherapeutic agent successfully used in the treatment of a wide range of malignancies while its usage is limited due to its dose-dependent toxicity. The present study was conducted to investigate the efficacy of naringin, an ubiquitous flavonoid, against Cis-induced striatum injury in Wistar aged rats. Briefly, the experimental procedures were divided in two sets of experiments. In the first, the animals were divided into 4 groups: control, Nar 25mg/kg, Nar 50mg/kg and Nar 100mg/kg. In the second, the animals were divided into 4 groups: Cis (5mg/kg/week for 5 consecutive weeks), Cis+Nar (25mg/kg), Cis+Nar (50mg/kg) and Cis+Nar (100mg/kg). The administration of Cis (5mg/kg/week for 5 consecutive weeks) resulted in a decline in the concentrations of reduced glutathione and ascorbic acid. The activity of membrane bound ATPases and glutathione peroxidase (GPx) were decreased while the activity of catalase (CAT) and superoxide dismutase (SOD) were increased. Further, in striatum tissue, Cis significantly enhance the mRNA gene expression of P53, nuclear factor κB pathway (NFκB) and tumor necrosis factor (TNF-α). Oxidative/nitrosative stress was evident in Cis group by increased malondialdehyde (MDA), protein carbonyls (PCO), reactive oxygen species (ROS) and nitrite concentration (NO). Naringin (25, 50 and 100mg/kg) administration was able to protect against deterioration in striatum tissue, abrogate the change in antioxidant enzyme activities and suppressed the increase in MDA, PCO, NO and TNF-α concentrations. Moreover, Nar inhibited P53, NFkB and TNF-α pathways mediated inflammation and apoptosis, and improved the histological changes induced by Cis. Thus, these findings demonstrated the neuroprotective nature of Nar by attenuating the pro-inflammatory and apoptotic mediators and improving antioxidant competence in striatum tissue. These results imply that Nar has perfect effect against Cis-induced striatum injury in aged rats, which should be developed as an effective food and healthcare product for the treatment of brain injury in the future.

Naringenin protects cardiac hypercholesterolemia-induced oxidative stress and subsequent necroptosis in rats

BACKGROUND In earlier studies, the supplementation of the natural compound Naringenin (NGEN), improved the liver oxidative and inflammatory status, which indicates its direct effect via inhibition of the nuclear factor κB pathway on high cholesterol-induced hepatic damages. In this regard, the present study highlights the mechanisms associated with the protective efficacy of NGEN in the heart tissue of hypercholesterolemic diet rats. RESULTS The animals exposed to a high cholesterol diet (HCD) for 90 days exhibited a significant increase in the levels of serum lactate dehydrogenase (LDH) and creatine kinase (CK) activities, nitric oxide (NO) levels, protein and lipid oxidative markers and cardiac lipids profile. Moreover, hypercholesterolemia decreased the levels of enzymatic and non enzymatic antioxidants associated with mitochondrial dysfunctions as proved by the decrease in the mitochondrial complexes in comparison to controls. Importantly, cholesterol-feeding significantly increased myocardial reactive oxygen species (ROS) and nuclear DNA damage and led to the activation of gene expression of the tumor necrosis factor-α (TNF-α) and receptor-interacting protein kinase 3 (RIP3) mRNA that contributed to the elucidation of cholesterol-induced necroptosis, a recently described type of programmed necrosis, in the cardiac tissue. CONCLUSIONS Our results show that the co-administration of NGEN (50 mg/kg/bw) in HCD rats improved all the altered parameters and provided insight into a possible molecular mechanism underlying NGEN suppression of necroptosis pathway in the heart.

Artemisia campestris leaf extract alleviates early diabetic nephropathy in rats by inhibiting protein oxidation and nitric oxide end products

Chronic hyperglycemia in diabetes leads to free radicals overproduction, which contributes to the development of diabetic nephropathy. The present study investigated the effects of Artemisia campestris (Ac), a plant of the Asteraceae family, on renal impairment and oxidative stress in alloxan-induced diabetic rats. Diabetes was induced by a single subcutaneous injection of alloxan (120 mg kg(-1)) in rats. Ac (200 mg kg(-1)) was administered to diabetic rats for 3 weeks. Diabetic renal injury was associated with hyperglycemia, increased serum creatinine, urea and uric acid levels. This nephropathophysiology was associated with a surproduction of nitric oxide (NO), malondialdehyde (MDA) and advanced oxidation protein products (AOPP) levels and a decrease in glutathione (GSH) levels. In addition, hyperglycemia increased the activities of antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx), in the kidney of diabetic rats. Treatment with Ac effectively ameliorated diabetic renal dysfunction by reducing oxidative and nitrosative stress. Histological studies also supported the experimental findings. The results suggested that Ac might act as a beneficial agent against renal dysfunctions developed in alloxan-induced diabetes.

Protective role of silymarin against manganese-induced nephrotoxicity and oxidative stress in rat.

Metal toxicity may occur after exposure from many sources. Oxidative stress is thought to be involved in manganese‐induced toxicity and leads to various health disorders. Silymarin (SIL), a natural flavonoid, has been reported to have many benefits and medicinal properties. The aim of this study was to assess the toxicity of manganese (Mn) on oxidative stress and DNA damage in the kidney of rats and its alleviation by SIL. Manganese was given orally in drinking water (20 mg MnCl2/mL) with or without SIL administration (100 mg /kg intraperitoneally) for 30 days. Our data showed that SIL significantly prevented Mn induced nephrotoxicity, indicated by both diagnostic indicators of kidney injury like plasma urea, uric acid and creatinine and urinary electrolyte levels and by histopathological analysis. Moreover, Mn‐induced profound elevation of the production of reactive oxygen species (ROS) and altered the levels of oxidative stress related biomarkers in kidney tissue. This is evidenced by the increase of lipid peroxidation, protein carbonylation, DNA fragmentation and urinary hydrogen peroxide, while, the activities of enzymatic antioxidant and glutathione level were decreased. Treatment with SIL reduced the alterations in the renal and urine markers, decreasing lipid peroxidation markers, increasing the antioxidant cascade and decreasing the Mn‐induced damage. All these changes were supported by histopathological observations. These findings suggested that the inhibition of Mn‐induced damage by SIL was due at least in part to its antioxidant activity and its capacity to modulate the oxidative damage.

Carbon tetrachloride-induced nephrotoxicity and DNA damage in rats: protective role of vanillin.

In this study, the protective effects of vanillin were evaluated against carbon tetrachloride (CCl4)-induced kidney damages in Wistar albino rats. CCl4 (1 ml/kg, intraperitoneally [i.p.]) caused a significant induction of renal disorder, oxidative damage and DNA fragmentation as evidenced by increased plasma creatinine, urea and uric acid levels, increased lipid peroxidation (malondialdehyde [MDA]) and protein carbonyl. Furthermore, glutathione levels, catalase, superoxide dismutase, glutathione transferase and glutathione peroxidase activities were significantly decreased. A smear without ladder formation on agarose gel was also shown, indicating random DNA degradation. Pretreatment of rats with vanillin (150 mg/kg/day, i.p.), for 3 consecutive days before CCl4 injection, protected kidney against the increase of MDA and degradation of membrane proteins compared to CCl4-treated rats and exhibited marked prevention against CCl4-induced nephropathology, oxidative stress and DNA damage. Kidney histological sections showed glomerular hypertrophy and tubular dilatation in CCl4-treated rats, however, in vanillin pretreated rats, these histopathological changes were less important and present a similar structure to that of control rats. These data indicated the protective role of vanillin against CCl4-induced nephrotoxicity and suggested its significant contribution of these beneficial effects.

Endocrine disrupting potential and reproductive dysfunction in male mice exposed to deltamethrin

Pesticide exposure may affect semen quality and male fertility in humans. The aim of the present work was to elucidate the adverse effects of deltamethrin (Delta), a synthetic pyrethroid, on exposed male mice and their offspring. Adult male Albino/Swiss mice received deltamethrin (5 mg/kg) daily for 35 days and mated with untreated females to produce offspring. Classical measurements of ejaculate and sperm quality and testicular histopathological changes were assessed. Deltamethrin treatment affects sperm quality and quantity in the ejaculated semen of mice that had also markedly impaired libido as measured by indices of mating and fertility and number of pregnant females housed with male mice exposed to this pesticide. Exposure mice to deltamethrin significantly decreased their testosterone and inhibin B levels and affected reproductive performance. Testes of exposed mice showed marked histopathological alterations as compared to the control group. The mice exposed to 5 mg/kg body weight/day of deltamethrin showed severe alterations of the seminiferous tubules, sloughing of the germ cells, the vacuolization of germ cell cytoplasm, and the disruption of spermatogenic cells compared to the control group. Altered pregnancy outcomes were directly attributed to damage of sperm of male mice exposed to deltamethrin compared to the control group. We concluded that exposure to deltamethrin affected the reproductive system of male mice explored by altered total sperm density, motility, and morphology in mice spermatozoa.

Protective effect of vanillin against carbon tetrachloride (CCl4)-induced oxidative brain injury in rats

This study investigated the protective effects of vanillin against acute brain damage induced by carbon tetrachloride (CCl4) in rats. The study was performed on 32 male rats divided into four groups: a control group, vanillin group ([Va] 150 mg/kg/day, intraperitoneally [i.p.]) and CCl4 toxication groups received a single injection of CCl4 (1 ml/kg, i.p.; CCl4 and Va + CCl4 groups). The degree of protection in brain tissue was evaluated by the levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase, glutathione transferase, glutathione peroxidase and nitric oxide (NO). Vanillin showed a significant brain-protective effect by decreasing the level of lipid peroxidation and NO2 and elevated the activities of antioxidative enzymes and level of GSH. Consequently vanillin blocked oxidative brain damage induced by CCl4 in rats.

Naringin inhibits the invasion and migration of human glioblastoma cell via downregulation of MMP-2 and MMP-9 expression and inactivation of p38 signaling pathway

Gliomas are the most common and malignant primary brain tumors. They are associated with a poor prognosis despite the availability of multiple therapeutic options. Naringin, a common dietary flavonoid abundantly present in fruits and vegetables, is believed to possess strong anti-proliferative and anti-cancer properties. However, there are no reports describing its effects on the invasion and migration of glioblastoma cell lines. Our results showed that the treatment of U251 glioma cell lines with different concentrations of naringin inhibited the invasion and migration of these cells. In addition, we revealed a decrease in the levels of matrix metalloproteinases (MMP-2) and (MMP-9) expression as well as proteinase activity in U251 glioma cells. In contrast, the expression of tissue inhibitor of metalloproteinases (TIMP-1) and (TIMP-2) was increased. Furthermore, naringin treatment decreased significantly the phosphorylated level of p38. Combined treatment with a p38 inhibitor (SB203580) resulted in the synergistic reduction of MMP-2 and MMP-9 expressions correlated with an increase of TIMP-1 and TIMP-2 expressions and the anti-invasive properties. However, p38 chemical activator (anisomycin) could block these effects produced by naringin, suggesting a direct downregulation of the p38 signaling pathway. These data suggest that naringin may have therapeutic potential for controlling invasiveness of malignant gliomas by inhibiting of p38 signal transduction pathways.