H. Tounsi

Prognostic Impact of Angiogenesis in Nonmuscle Invasive Bladder Cancer as Defined by Microvessel Density after Immunohistochemical Staining for CD34

Bladder cancer is the second most common malignancy of the urogenital region. The majority of bladder cancer deaths occur as a consequence of metastatic disease. Microvessel density (MVD), a surrogate marker for angiogenesis, has been shown to be predictive of progression and poor prognosis. The aim of this study was to evaluate the predictive value and prognostic significance of angiogenesis in human non muscle invasive bladder cancer (NMIBC) treated by BCG immunotherapy. The frozen sections of 28 non muscle invasive bladder cancer specimens were stained with CD34 antibody to label the vascular endothelium using the standard streptavidin-biotin immunoperoxidase method. Angiogenic activity was measured using microvessel count determined by the expression of vascular markers CD34.The prognostic significance of tumor stage, grade, loci number, tumor size, age and CD34 expression in determining the risk for recurrence was studied with both univariate and multivariate methods of analysis. According to univariate analysis of the prognostic significance for tumor stage, grade, tumor size, loci number, age and CD34 expression, in patients with NMIBC, the pT1 stage and high grade seem to be associated in a statistically significant manner with higher risk for recurrence (P=0.004, P=0.004, respectively). In the other hand, multivariate Cox regression’s analysis showed that microvessel density and multiplicity were independent predictor of recurrence after BCG immunotherapy (p=0.016, p=0.032, respectively). This study provides strong evidence that CD34 MVD is associated with recurrence after BCG immunotherapy. Independent studies, however, will be required on larger cohort to validate these findings.

Myrtle berry seed aqueous extract inhibits human neutrophil myeloperoxidase in vitro and attenuates acetic acid-induced ulcerative colitis in rats

We aimed in the present study to investigate the protective effect of a myrtle (Myrtus communis L.) berry seed aqueous extract (MBSAE) on acetic acid (AA)-induced colitis in rats as well as the mechanism implicated in this coli-protection. The use of the LC/MS technique allowed us to identify 18 phenolic compounds in the MBSAE. Secondly, we found that the MBSAE inhibited the luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionylleucyl-phenylalanine (fMLF) or phorbolmyristate acetate (PMA) stimulated neutrophils in a dose-dependent manner. The MBSAE had no effect on superoxide anions, but it inhibited H2O2 production in the cell free system stimulated with horseradish peroxidase (HRPO) and MPO release from the neutrophils. In vivo, the pre-treatment of rats with sulfasalazine (100 mg kg−1) and the MBSAE (25, 50, and 100 mg kg−1) significantly reduced AA-induced colonic mucosa lesions as well as histopathological changes. The MBSAE counteracted AA-induced lipid peroxidation and the depletion of the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). We also found that the myrtle extract inhibited the increase of the plasma scavenging activity (PSA) and preserved the content of non-enzymatic antioxidants such as sulfhydryl groups (–SH) and reduced glutathione (GSH). More importantly, acetic acid administration increased colonic hydrogen peroxide (H2O2), free iron and calcium levels, while the MBSAE pre-treatment reversed all intracellular mediator perturbations. In conclusion, our data suggests that the MBSAE exerted a potential protective effect against AA-induced injury and oxidative stress in the rat colon. This coli-protection might be related in part to its antioxidant and ROS scavenging activities or by negatively regulating Fenton reaction components such as H2O2 and free iron, which are known to lead to cytotoxicity mediated by intracellular calcium deregulation.

Protective effect of Artemisia campestris extract against aspirin-induced gastric lesions and oxidative stress in rat

The present study aims at evaluating the antiulcer and antioxidant effect of Artemisia campestris aqueous extract (ACAE) as well as the mechanism of action involved in such gastroprotection. The use of LC/MS allowed the identification of 11 phenolic compounds and the colorimetric analysis demonstrated that the ACAE exhibited an important in vitro antioxidant activity. We first showed that in vivo ACAE protected against macroscopic and histological changes induced by aspirin in stomach mucosa. Aspirin administration was accompanied by an oxidative stress status assessed by an increase in malondialdehyde (MDA) level, a decrease in the content of sulfhydryl –(SH) groups and a depletion of antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Pre-treatment with ACAE protected against aspirin-induced gastric oxidative stress. More importantly, aspirin administration increased plasma and tissue hydrogen peroxide (H2O2), free iron and calcium levels, while the ACAE pre-treatment reversed all the effects of aspirin-induced intracellular mediators. In conclusion, we suggest that Artemisia campestris aqueous extract has potent antiulcer and antioxidant properties. This gastroprotection offered by ACAE might be related partly to the safety of sulfhydryl group as well as its opposite effect on some intracellular mediators such as hydrogen peroxide, free iron and calcium.

Prognostic Value of Bcl-2 and Bax Tumor Cell Expression in Patients with Non Muscle-Invasive Bladder Cancer Receiving Bacillus Calmette-Guerin Immunotherapy

Apoptosis is the distinctive form of programmed cell death that complements cell proliferation in maintaining normal tissue homeostasis. The significance of constitutive apoptosis in the recurrence of Non Muscle Invasive Bladder Cancer has yet to be investigated. The aim of this study is to investigate the prognostic significance of Bax and Bcl-2 in terms of recurrence after BCG immunotherapy. Immunohistochemical analysis was performed on frozen biopsies to evaluate bcl-2 and Bax proteins expression in 28 cases of NMIBC. All patients with confirmed NMIBC were treated with intravesical BCG-immunotherapy. The follow up was performed for 26 months. The correlation between clinicopathological, immunohistochemical data and the response to BCG therapy was performed. Univariate analysis showed that, PT1 stage, High grade and Bax expression increased significantly the risk of recurrence (P = 0.015, P = 0.015 and P= 0.034 respectively). In addition, multivariate analysis selected the model involving stage, age, Bax and Bcl-2 expression as the best independent variables of recurrence. In conclusion, the expression of Bcl-2 and Bax in NMIBC could have a prognostic value in assessing the risk of recurrence after BCG immunotherapy. These findings require further investigations on larger cohort in order to ascertain new molecular markers of the response to BCG immunotherapy.

Ameliorative and antioxidant effects of myrtle berry seed (Myrtus communis) extract during reflux-induced esophagitis in rats

Abstract Context Myrtle, Myrtus communis L. (Myrtaceae), is a medicinal plant well known for its richness in phenolic compounds and its beneficial effects for the treatment of gastrointestinal disorders. Objective In the present work, the protective effect of the myrtle berry seed aqueous extract (MBSAE) against esophageal reflux (ER)-induced damage in esophagus mucosa as well as the mechanisms implicated was determined. Materials and methods In this respect, adult male Wistar rats were used and divided into seven groups: Control, ER, ER + various doses of MBSAE, ER + famotidine or ER + gallic acid. The ER was induced and animals were per orally (p.o.) treated with MBSAE or reference molecules during 6 h. The phytochemical screening was determined using colourimetric analysis. Results MBSAE is rich in total polyphenols and anthocyanins and exhibited an important in vitro antioxidant activity. In vivo, we firstly found that ER led to marked macroscopic and histopathological changes in esophagus. The results showed, also, that the ER was accompanied by a state of oxidative stress as assessed by an increase of lipid peroxidation, a decrease of the sulphhydryl groups and glutathione levels, as well as antioxidant enzyme activities depletion. MBSAE abrogated all morphological, histopathological and biochemical alterations. We showed also that ER increased esophageal calcium, hydrogen peroxide (H2O2) and free iron levels while MBSAE treatment protected against intracellular mediators deregulation. Conclusion Our data suggest that MBSAE exerted a potential protective effect against ER-induced damage in rat esophagus, at least in part, due to its antioxidant properties.

Protective effect of chamomile (Matricaria recutita L.) decoction extract against alcohol-induced injury in rat gastric mucosa

BACKGROUND Matricaria recutita L. (Asteraceae), German chamomile, has been widely used in the traditional Tunisian medicine because of having the powerful health benefits. the current study was conducted to determine the protective effect of chamomile (Matricaria recutita L.) decoction extract (CDE) in ethanol-induced ulcer and oxidative stress on gastric mucosa in rat. METHODS Adult male wistar rats were used and divided into seven groups: Control, EtOH, EtOH+various doses of CDE (25, 50 and 100mg/kg, b.w.), EtOH+famotidine (FAM) and EtOH+ascorbic acid (AA). Gastric ulceration was induced by EtOH (4g/kg, b.w. p.o.). RESULTS Firsly, we found that acute alcohol administration leads to mark macroscopic and histologic changes in gastric mucosa. EtOH also induced lipoperoxidation (486.99%), thiol (-SH) groups decrease (40.98%) as well as antioxidant enzyme activity depletion such as superoxide dismutase (SOD) (49.05%), catalase (CAT) (46.80%) and glutathione peroxidase (GPx) (38.20%). Our results also demonstrated that alcohol intoxication increased tissue and plasmatic hydrogen peroxide, calcium and free iron levels. More importantly, CDE reversed all macroscopic, histologic and biochemical changes induced by EtOH administration. CONCLUSION A potential gastropreotective effect of CDE against EtOH-induced ulcer and oxidative stress might be partially to its antioxidant properties as well as to various gastric mucosal defense mechanisms, including protection of gastric sulfhydryls and its opposite effect on some intracellular mediators such as free iron, hydrogen peroxide and calcium.

Fatty acid composition and mechanisms of the protective effects of myrtle berry seed aqueous extract in alcohol-induced peptic ulcer in rat

This study aimed to investigate the antiulcer and antioxidant activities of myrtle berry seed aqueous extract (MBSAE) in a peptic ulcer model induced by ethanol in male Wistar rats. MBSAE is rich in total polyphenols, total flavonoids, and unsaturated fatty acids, particularly linoleic (18:2) and oleic (18:1) acids. MBSAE also exhibited in vitro antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50 = 172.1 μg/mL) and superoxide anion (IC50 = 200.24 μg/mL) scavenging activities. In vivo, MBSAE provided dose-dependent protection against ethanol-induced gastric and duodenal macroscopic and histological alterations. Also, it inhibited secretory profile disturbances and lipid peroxidation, and preserved normal antioxidant enzyme activities and nonenzymatic antioxidant levels. More importantly, we showed that acute alcohol intoxication increased gastric and duodenal calcium, hydrogen peroxide, and free iron levels, whereas MBSAE treatment protected against intracellular mediator deregulation. In conclusion, we suggest that MBSAE has potent protective effects against alcohol-induced peptic ulcer in rat. This protection might be related in part to its antioxidant properties as well as its opposite effects on some studied intracellular mediators.

Histopathological, biochemical and molecular changes of reproductive function after malathion exposure of prepubertal male mice

We aimed in the present work to evaluate the implication of oxidative stress in the toxicological effects of subchronic malathion exposure on reproductive function in mice. In this respect, we used prepubertal male mice separated into two groups: a control and a malathion treated group. Animals were treated by gavage (per orally, p.o.) with malathion at 200 mg kg−1, body weight (b.w.) during thirty days. We found that malathion treatment leads to the alteration of semen parameters such as a decrease of testosterone level and acetylcholinesterase activity, an induction of apoptosis and necrosis in spermatozoa as well as a decrease of reproductive performance of male mice. The histopathological examination showed a marked change in the testis tissue. Malathion intoxication was by an increase of malondialdehyde (MDA) level, a decrease of sulfhydril groups (–SH) content, as well as a depletion of antioxidant enzyme activities such as catalase (CAT), total superoxide dismutase (SOD), Cu/Zn–SOD and Mn–SOD in testis and epididymis. More importantly, malathion treatment clearly induced a decrease in mRNA expression of COX isoenzyme in cauda and epididymis as well as GPx-4 in testis and GPx-5 in epididymis. These data suggest that a marked deregulation of reproductive function in prepubertal male mice exposed to malathion might be partly due to pro-oxidant properties of the examined compound.

Hepatoprotective effect of carob against acute ethanol-induced oxidative stress in rat

The present study was undertaken to determine whether subacute treatment with aqueous extract of carob (Ceratonia siliqua L.) pods (AECPs) protects against ethanol (EtOH)-induced oxidative stress in rat liver. Animals were divided into four groups: control, carob, EtOH and EtOH + carob. Wistar rats were intraperitoneally pretreated with AECP (600 mg/kg body weight (bw)) during 7 days and intoxicated for 6 h by acute oral administration of EtOH (6 g/kg bw) 24 h after the last injection. We found that acute administration of EtOH leads to hepatotoxicity as monitored by the increase in the levels of hepatic marker aspartate aminotransferase and alanine aminotransferase as well as hepatic tissue injury. EtOH also increased the formation of malondialdehyde in the liver, indicating an increase in lipid peroxidation and depletion of antioxidant enzyme activities as superoxide dismutase, catalase and glutathione peroxidase. Subacute carob pretreatment prevented all the alterations induced by EtOH and returned their levels to near normal. Importantly, we showed that acute alcohol increased hepatic and plasmatic hydrogen peroxide and free iron levels. The carob pretreatment reversed EtOH effects to near control levels. These data suggest that carob could have a beneficial effect in inhibiting the oxidative damage induced by acute EtOH administration and that its mode of action may involve an opposite effect on plasma and tissue-free iron accumulation. Indeed, carob can be offered as a food additive to protect against EtOH-induced oxidative damage.

Epidemiological trends and clinicopathological features of cutaneous melanoma in sporadic and xeroderma pigmentosum Tunisian patients

Epidemiological features and trends of cutaneous melanoma (CM) in North‐African populations remain unclear. Those populations are of particular interest as they belong to a mosaic of various other origins (sub‐Saharan, European Ancestry, and North‐African Berbers). The aim of this study is to draw epidemiological profile and clinicopathological features of CM in the Tunisian population.