Najla Hfaiedh

Evaluation of antioxidant and antiulcerogenic activities of Opuntia ficus indica f. inermis flowers extract in rats.

The Opuntia ficus indica f. inermis methanolic flowers extract (OMFE) was phytochemical studied, in vitro tested for their potential antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, linoleic acid peroxidation assays and in vivo evaluated for its ability to prevent ethanol-induced gastric ulcer in rats. The OMFE was rich in polysaccharide, phenolics and flavonoids contents and exhibited a moderate in vitro antioxidant activity when compared with (+)-catechin and ascorbic acid. Pre-treatment with OMFE at oral doses 250, 500 and 1000 mg/kg body weight was found to provide a dose-dependent protection against ethanol-induced gastric ulcer by averting the deep necrotic lesions of the gastric epithelium, by preserving normal antioxidant enzymes activities, by inhibiting the lipid peroxidation, the oxidation of protein and the DNA fragmentation in gastric mucosa. The antiulcerogenic activity of OMFE might be due to a possible synergistic antioxidant and antihistaminic-like effects.

Antioxidant and antiulcerogenic activities of Opuntia ficus indica f. inermis root extract in rats.

Opuntia ficus indica f. inermis methanolic root extract (ORE) was investigated for phenolic and flavonoids contents, in vitro evaluated for DPPH radical scavenging activity, reducing power and in vivo tested for its gastro-protective ability against 80% ethanol induced ulcer in rats. Phytochemical test of ORE were positive for phenolic and flavonoid contents. DPPH radical scavenging activity and reducing power of ORE showed an EC(50) of 118.65±2.51 μg/ml and 300 μg/ml respectively. In vivo the pre-treatment of rats with ranitidine (50 mg/kg) and 200, 400, and 800 mg/kg doses of ORE significantly (p<0.05) reduced the 80% ethanol induced-ulcer lesion, with a rate of 82.68%, 49.21%, 83.13%, and 92.59% respectively, and prevented the depletion of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total glutathione (GSH), and inhibited the increase of myeloperoxidase (MPO) and malondialdehyde (MDA) in rat stomach tissues when compared with ethanol group. Also pre-treatment with ORE marked a dose-dependent attenuation of histopathology changes induced by ethanol. Phenolic and flavonoids wealth, radical scavenging activity, and reducing power, have been implicated for antiulcer property of ORE.

Protective effect of cactus (Opuntia ficus indica) cladode extract upon nickel-induced toxicity in rats

The purpose of this study carried out on male Wistar rats, was to evaluate the protective effects of regular ingestion of juice from the prickly pear cactus (Opuntia ficus indica) cladodes against nickel chloride toxicity. Rats were given either normal tap water or water containing 25% of cactus juice for one month. Then, rats of each group were injected daily, for 10 days, with either NiCl(2) solution (4mg (30micromol)/kg body weight) or with the same volume of saline solution (300mM NaCl). Significant increases of lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase activities and of cholesterol, triglycerides and glucose levels were observed in blood of nickel-treated rats. In the liver, nickel chloride was found to induce an oxidative stress evidenced by an increase in lipid peroxidation and changes in antioxidant enzymes activities. Superoxide-dismutase (SOD) activity was found to be increased whereas glutathione peroxidase and catalase activities were decreased. These changes did not occur in animals previously given cactus juice, demonstrating a protective effect of this vegetal extract.

Changes in growth rate and thyroid- and sex-hormones blood levels in rats under sub-chronic lithium treatment

Lithium therapy, mainly used in curing some psychiatric diseases, is responsible for numerous undesirable side effects. The present study is a contribution to the understanding of the pathophysiological mechanisms underlying lithium toxicity. Male and female mature rats were divided into three batches and fed commercial pellets: one batch was the control and the second and third batches were given 2 g (Li1) and 4 g (Li2) of lithium carbonate/kg of food/day, respectively. After 7, 14, 21 and 28 days, serum levels of free tri-iodothyronine (FT3), thyroxine (FT4), testosterone and estradiol were measured. Attention was also paid to growth rate and a histological examination of testes or vaginal mucosa was carried out. In treated rats, a dose-dependent loss of appetite and a decrease in growth rate were observed, together with symptoms of polydypsia, polyuria and diarrhea. Lithium serum concentrations increased from 0.44 mM (day 7) to 1.34 mM (day 28) in Li1 rats and from 0.66 to 1.45 mM (day 14) in Li2 rats. Li2 treatment induced a high mortality after 14 days, reaching 50-60% in female and male animals. From these data, the LD50 (14 days Li2 chronic treatment) was calculated to be about 0.3 g/day per kilogram of animal, leading to Li serum concentrations of about 1.4 mM. A significant decrease of FT3 and FT4 was observed in treated rats. This effect appeared immediately for the highest dose and was more pronounced for FT3, resulting in an increase of the FT4/FT3 ratio. In males, testosterone decreased and spermatogenesis was stopped. Conversely, in females, estradiol increased in a dose-dependent manner as the animals were blocked in the diestrus phase at day 28. This finding supports a possible antagonistic effect of lithium on the estradiol receptors.

Interactions d’une restriction calorique avec les effets du Nickel sur la reproduction chez le rat

ResumeDes études épidémiologiques chez l’homme ont montré qu’il existait, depuis 1960, des signes de diminution de plusieurs paramètres du spermogramme avec augmentation de certaines pathologies génitales masculines. La contamination croissante de l’environnement par des composés chimiques semble être un facteur de causalité. Par ailleurs, divers auteurs avancent l’hypothèse que la restriction calorique a un effet bénéfique sur la santé ou la longévité.Ce travail a pour objectif de comparer les effects du nickel sur les processus de reproduction de rats nourris soit tous les jours, soit une jour sur deux, afin d’évaluer les possibles effets bénéfiques, ou non, d’une restriction calorique sur la fécondité des rats.Dans ce but, nous avons utilisé des rats mâles et femelles de soucheWistar, nourris soit tous les jours (N) soit un jour sur deux: jeûne intermittent (J). Après un mois de ce traitement, les rats (N) et (J) ont été répartis en 2 groupes: l’un abreuvé avec de l’eau du robinet (groupes NO et JO), l’autre abreuvé avec la même eau enrichie en chlorure de nickel (100 mg/L, groupes NNi et JNi). Le jeûne intermittent se poursuit parallèlement au traitement par le nickel, et ceci durant 2, 4, 10, 16, 30 et 60 jours. Pour l’exploration du dialdéhyde malonique (MDA), le nickel est administré par injection intra-péritonéale à raison de 4 mg NiCl2/kg de poids corporel durant 1, 3, 5, et 10 jours.Nos résultats montrent que le nickel entraîne une atrophie des tubes séminifères avec une diminution du nombre des spermatozoïdes, et une diminution du taux de la testostérone sérique. Chez les femelles une diminution du nombre de follicules cavitaires a été observée.Le jeûne intermittent a induit les mêmes types de perturbations avec des diminutions du nombre des spermatozoïdes mobiles et du taux de testostérone plus importantes qu’après exposition au nickel. Avec les deux facteurs associés, jeûne et nickel, les effets déjà observés ne sont pas amplifiés.L’analyse des croisements intergroups a montré que le taux de gestation et surtout le nombre moyen d’implantations étaient diminués chez les rats exposés au nickel et/ou soumis au jeûne intermittent. Le taux de gestation le plus faible (55%) a été observé chez des femelles (NNi) croisées avec des mâles témoins (NO). Le nombre d’implantations le plus bas a été observé chez les femelles témoins (NO) croisées avec des mâles (NNi). Le nickel n’a pas entraîné de baisse complémentaire de la fertilité chez les rats soumis au jeûne intermittent.Le dosage du MDA a montré que le nickel induit une péroxydation lipidique au niveau des tissus utérin et ovarien. Cependant l’augmentation relative du taux de MDA est plus faible chez les rats JNi que NNi, c’est-à-dire dans le cas où le nickel est associé au jeûne intermittent.Nos résultats suggèrent que le nickel et le jeûne intermittent diminuent la fertilité des rats par deux mécanismes différents dont les effects ne s’additionnent pas. Associé au jeûne intermittent, le nickel devient non toxique, ceci est confirmé par le suivi des taux du MDA. L’effet hypocalorique du jeûne intermittent pourrait être à l’origine de l’inhibition des effets cytotoxiques du nickel métal classé parmi les stress oxydants.AbstractHuman epidemiological studies have demonstrated signs of a reduction, since 1960, of several parameters of the sperm count with an increase of certain male genital tract diseases. The increasing contamination of the environment by chemical compounds appears to be an aetiological factor. Various authors have also proposed the hypothesis that caloric restriction has a beneficial effect on health or longevity.This study was deisgned to compare the effects of nickel on the reproductive functions of rats fed either daily or every second day, in order to evaluate the possible beneficial effects of caloric restriction on rat fertility.This study was conducted with male and female Wistar rats, fed either daily (N), or every second day: intermittent fasting (F). After one month of this treatment, (N) and (F) rats were divided into 2 groups: one group received tap water (NO and FO groups), and the other received the same water enriched with nickel chloride (100 mg/L, NNi and FNi groups). Intermittent fasting was continued in parallel with nickel treatment with for 2, 4, 10, 16, 30 and 60 days. To study malonic dialdehyde (MDA) levels, nickel was administered by intraperitoneal injection at the dosage of 4 mg NiCl2/kg of body weight for 1, 3, 5 and 10 days.Our results show that nickel induces atrophy of the seminiferous tubules with a reduction of the sperm count and a reduction of serum testosterone levels. A reduction of the number of ovarian follicles was observed in females.Intermittent fasting induced the same types of disturbances with more marked reductions of the number of mobile spermatozoa and serum festosterone levels than those observed after exposure to nickel. The combination of the two factors, fasting and nickel, did not amplify these effects.Analysis of intergroup crosses showed that the pregnancy rate and especially the mean number of implantations were decreased in rats exposed to nickel and/or submitted to intermittent fasting. The lowest pregnancy rate (55%) was observed in (NNi) females crossed with (NO) control males. The smallest number of implantations was observed in (NO) control females crossed with (NNi) males. Nickel did not induce any additional reduction of fertility in rats submitted to intermittent fasting.MDA assays showed that nickel induces lipid peroxidation in ovarian and uterine tissues. However, the relative increase of the MDA level was lower in FNi than NNi rats, i.e. when nickel was associated with intermittent fasting.Our results suggest that nickel and intermittent fasting decrease fertility in rats via two different mechanisms whose effects are not additive. When associated with intermittent fasting, nickel becomes non-toxic, as confirmed by montoring of MDA levels. The low-calorie effect of intermittent fasting could be responsible for inhibition of the cytotoxic effects of metallic nickel classified as an oxidative stress.

Chemical Composition and Antioxidant, Analgesic, and Anti-Inflammatory Effects of Methanolic Extract of Euphorbia retusa in Mice

Plants provide an alternative source to manage different human disorders due to various metabolites. The aim of this study is to investigate the phytochemical constituents of the methanolic extracts of Euphorbia retusa and to evaluate their antioxidant, anti-inflammatory, and analgesic activities. The phytochemical results obtained by HPLC and by chemical assay reactions have revealed the richness of the methanolic extract of E. retusa in active compounds, in particular polyphenols, flavonoids, and tannins. The methanolic extract shows significant antioxidant activities in vitro, in the DPPH and the FRAP assays. The antinociceptive activity was evaluated using acetic acid and hot-plate models of pain in mice. The anti-inflammatory activity was evaluated by carrageenan-induced paw edema. Oral pretreatment with the methanolic extract of E. retusa (200u2009mg/kg) exhibited a significant inhibition of pain induced either by acetic acid or by the heating plate and in a manner comparable to the standard drug paracetamol. E. retusa significantly reduced paw edema starting from the 3rd hour after carrageenan administration by increasing the activity of antioxidant enzymes (SOD, CAT, and GPx) in liver and paw tissues and decreasing the levels of MDA. These results may confirm the interesting potential of this plant as a treatment of various inflammatory and pain diseases.

Incidences de la restriction calorique et du Nickel sur l'aromatase testiculaire du rat

ResumeDes études épidémiologiques chez l’homme ont montré qu’il existait, depuis 1960, des signes d’augmentation de certaines pathologies génitales masculines. La contamination croissante de l’environnement par des composés chimiques semble être un facteur de causalité. Par ailleurs, divers auteurs avancent l’hypothèse que la restriction calorique a un effet bénéfique sur la reproduction masculine.Ce travail a pour objectif de comparer les effets du nickel sur les processus de reproduction, entre autres l’étude de l’aromatase, chez des rats mâles nourris soit tous les jours, soit un jour sur deux, afin d’évaluer les possibles effets bénéfiques, ou non, d’une restriction calorique sur la fertilité des rats mâles.Dans ce but, nous avons utilisé des rats mâles de souche « Wistar » nourris, soit tous les jours (groupe N), soit un jour sur deux (jeûne intermittent) (groupe J). Après un mois de ce traitement, les rats des deux lots (N) et (J) sont répartis chacun en deux groupes: l’un injecté intra-péritonéalement avec du NaCI 9‰ (groupes NO et JO), l’autre injecté intra-péritonéalement avec du NiCl2 à raison de 4mg/kg (groupes NNi et JNi). Le jeûne intermittent se poursuit parallèlement au traitement par le nickel, et ceci durant 1, 3, 5 et 10 jours.Nous avons choisi pour notre étude comme biomarqueurs sexuels: dosage sérique des oestrogènes, dosage des ARN totaux et l’exploration moléculaire de l’ARNm de l’aromatase testiculaire.L’étude de l’aromatase montre que le nickel seul stimule l’activité de l’aromatase testiculaire et provoque la dégradation des ARN totaux durant le 3èmeet le 10ème jours de traitement.Le jeûne intermittent seul n’induit pas de variations significatives. Dans le cas où le nickel est associé au jeûne intermittent, il semble que pour le taux des ARN totaux testiculaires, l’effet du jeûne l’emporte, pas de dégradation des ARN totaux, d’où ses effets bénéfiques en protégeant les ARN totaux des effets délétères du nickel. On note aussi une surexpression de l’ARNm de l’aromatase vers le 10ème jours de traitement.L’effet hypocalorique du jeûne intermittent pourrait être à l’origine de l’inhibition des effets cytotoxiques du nickel, métal classé parmi les stress oxydants.AbstractThis study was designed to determine whether intermittent fasting induces malnutrition that, according to many authors, accentuates the cytotoxic effects of environmental pollutants, or caloric restriction that reduces these effects.Ninety six male Wistar rats (180g) were divided into two groups: one group was fed daily (N) and the other group was fed every second day (J) for one month. At the end of one month, each group was then divided into two subgroups, one subgroup received an injection of 0.9% NaCI (groups NO and JO), the other subgroup received an injection of 4 mg/kg NiCIb2 (groups NNi and JNi).Intermittent fasting was continued in parallel to treatment for 1, 3, 5 and 10 days.Under these experimental conditions, nickel increased testicular aromatase activity and altered total RNA, while no alteration of these biomarkers was observed with intermittent fasting.The combination of these two factors, nickel and intermittent fasting, did not amplify these effects. In contrast, protection of RNA by intermittent fasting was observed, especially overexpression of aromatase mRNA.