Use of molecular and in silico bioinformatic tools to investigate pesticide binding to insect (Lepidoptera) phenoloxidases (PO): insights to toxicological aspects.

In the present work, the promising bioinformatic tools, based on structure-affinity analysis, allowed to screen several pesticides supposed to bind to the insect immune Phenoloxidases (PO). First, the binding of aminoparathion, a reference compound, to the PO was structurally (3D) validated in accordance with previous reports. Second, using the same docking conditions, a range of pesticides was checked for their binding ability to the crystal 3D structure (PDB 3HSS) of the insect Manduca sexta (Lepidoptera) PO. The obtained data showed that many of the tested pesticides were able to bind, in silico, to M. sexta PO. The combination of in vitro (chemical and biochemical) and in silico (automated docking) approaches was found advantageous to elucidate the behavior of phenolic pesticides as substrate-analogues when binding to the active site of insect POs. Our findings emphasize new ecotoxicological aspects of pesticide residues in the agro-chemical and environmental circles.

Green tea decoction improves glucose tolerance and reduces weight gain of rats fed normal and high-fat diet.

Green tea containing polyphenols exerts antidiabetic and antiobesity effects, but the mechanisms involved are not fully understood. In this study, we first analyzed and compared polyphenol compounds [epigallocatechin gallate (EGCG), epigallocatechin (EGC)] in decoction of green tea leaves versus usual green tea extracts. Second, the effects of acute (30 min) or chronic (6 weeks) oral administration of green tea decoction (GTD) on intestinal glucose absorption were studied in vitro in Ussing chamber, ex vivo using isolated jejunal loops and in vivo through glucose tolerance tests. Finally, we explore in rat model fed normal or high-fat diet the effects of GTD on body weight, blood parameters and on the relative expression of glucose transporters SGLT-1, GLUT2 and GLUT4. GTD cooked for 15 min contained the highest amounts of phenolic compounds. In fasted rats, acute administration of GTD inhibited SGLT-1 activity, increased GLUT2 activity and improved glucose tolerance. Similarly to GTD, acute administration of synthetic phenolic compounds (2/3 EGCG+1/3 EGC) inhibited SGLT-1 activity. Chronic administration of GTD in rat fed high-fat diet reduced body weight gain, circulating triglycerides and cholesterol and improved glucose tolerance. GTD-treated rats for 6 weeks display significantly reduced SGLT-1 and increased GLUT2 mRNA levels in the jejunum mucosa. Moreover, adipose tissue GLUT4 mRNA levels were increased. These results indicate that GTD, a traditional beverage rich in EGCG and EGC reduces intestinal SGLT-1/GLUT2 ratio, a hallmark of regulation of glucose absorption in enterocyte, and enhances adipose GLUT4 providing new insights in its possible role in the control of glucose homeostasis.

PCR-based screening for the most prevalent alpha 1 antitrypsin deficiency mutations (PI S, Z, and Mmalton) in COPD patients from Eastern Tunisia.

It is generally agreed that the protease inhibitor (PI) alleles PI*S (Val264Glu) and PI*Z (Lys342Glu) are the most common alpha 1 antitrypsin deficiency variants worldwide, but the PI*Mmalton allele (ΔPhe52) prevails over these variants in some Mediterranean regions. In eastern Tunisia (Mahdia), we screened 100 subjects with chronic obstructive pulmonary disease for these variants. The PI*S and PI*Z alleles were genotyped by the previously described SexAI/Hpγ99I RFLP-PCR. We provide here a new method for PI*Mmalton genotyping using mismatched RFLP-PCR. These methods are suitable for routine clinical application and can easily be reproduced by several laboratories, since they do not require extensive optimization, unlike the previously described bidirectional allele-specific amplification PCR for PI*Mmalton genotyping. Our results were in agreement with previous reports from central Tunisia (Kairouan), suggesting that the PI*Mmalton mutation is the most frequent alpha 1 antitrypsin deficiency-related mutation in Tunisia.

Protective effects of crude garlic by reducing iron-mediated oxidative stress, proliferation and autophagy in rats.

The impact of garlic, known for its antioxidant activities, on iron metabolism has been poorly investigated. The aim of this work was to study the effect of crude garlic pre-treatment on iron-mediated lipid peroxidation, proliferation and autophagy for 5 weeks. Rats were fed distilled water or garlic solution (1 g/kg body weight) by gavage for the first 3 weeks as pre-treatment and received a basal diet supplemented or not with ferrous sulfate (650 mg Fe/kg diet) for the last 2 weeks of treatment. Immunohistochemistry labeling and ultrastuctural observations were used to evaluate the iron deleterious effects in the liver. Iron supplementation induced cell proliferation predominantly in non parenchymal cells comparing to hepatocytes, but not apoptosis. In addition, iron was accumulated within the hepatic lysosomes where it triggers autophagy as evidenced by the formation of autophagic vesicles detected by LC3-II staining. It also induced morphologic alterations of the mitochondrial membranes due to increased lipid peroxidation as shown by elevated iron and malondialdehyde concentrations in serum and tissues. Garlic pre-treatment reduced iron-catalyzed lipid peroxidation by decreasing the malondialdehyde level in the liver and colon and by enhancing the status of antioxidants. In addition, garlic reduced the iron-mediated cell proliferation and autophagy by lowering iron storage in the liver and protected mitochondrial membrane. Based on these results, garlic treatment significantly prevented iron-induced oxidative stress, proliferation and autophagy at both biochemical and histological levels due to its potent free radical scavenging and antioxidant properties.

Influence of garlic or its main active component diallyl disulfide on iron bioavailability and toxicity.

Garlic is regularly consumed and is known to have diverse biologic activities, particularly due to its antioxidant properties. In this study, we hypothesized that crude garlic can prevent iron-mediated oxidative stress in a rat model of nutritional iron overload, and we used an in vitro model to confirm the results. For the in vivo studies, rats received a basal diet supplemented with or without carbonyl iron (3%) and were fed distilled water or garlic solution (1g/kg body weight) by gavage for 3 weeks. The presence of both garlic and iron led to a 2-fold increase in plasma iron and a 50% increase in liver iron as compared with iron alone. However, garlic did not offer any protection against iron-induced oxidative stress. Duodenal divalent metal transporter-1 mRNA expression was fully repressed by iron and by the combined treatments but was also reduced by garlic alone. To confirm these data, we tested the effect of diallyl disulfide, one of the active components in garlic, in vitro on polarized Caco-2 cells. A 24-hour treatment decreased iron uptake at the apical side of Caco-2 cells but increased the percentage of iron transfer at the basolateral side. This probably resulted from a modest induction of ferroportin mRNA and protein expression. These results suggest that garlic, when given in the presence of iron, enhances iron absorption by increasing ferroportin expression. The presence of garlic in the diet at the dose studied does not seem to protect against iron-mediated oxidative stress.

Dermatology life quality index scores in vitiligo: reliability and validity of the Tunisian version.

BACKGROUND: Vitiligo is an important skin disease that can alter individual self-image and thus have major impact on the quality of life. AIMS: The objective of this study was to translate and to test the reliability and validity of the 10-item Dermatology Life Quality Index (DLQI) questionnaire in Tunisian vitiliginous patients. METHODS: Using a standard "forward-backward" translation procedure, the English language version of the questionnaire was translated into Persian (the Iranian official language) by two bilinguals. Seventy patients with vitiligo attending the Department of Dermatology, Regional Hospital, Medenine, Tunisia, were enrolled in this study. The reliability and internal consistency of the questionnaire were assessed by Cronbach's alpha coefficient and Spearman's correlation, respectively. Validity was performed using convergent validity. RESULTS: In all, 70 people entered into the study. The mean age of respondents was 28.3 (SD=11.09) years. Scores on the DLQI ranged from 0 to 24 (mean +/- SD, 7.05 +/- 5.13). Reliability analysis showed satisfactory result (Cronbach's alpha coefficient=0.77). There were no statistically significant differences between daily activity (DA) and personal relationship (PR) scale mean scores in generalized versus focal-segmental involvement in sufferers (P = 0.056, P = 0.053, respectively). There were also strong differences between the mean scores of the PR scale with the involvement of covered only and covered/uncovered areas (P = 0.016) that was statistically significant in the second group. CONCLUSIONS: The study findings showed that the Tunisian version of the DLQI questionnaire has a good structural characteristic and is a reliable and valid instrument that can be used for measuring the effects of vitiligo on quality of life.

Vitiligo treatment with vitamins, minerals and polyphenol supplementation.

BACKGROUND: Mammalian pigmentation results from the synthesis and accumulation of photo protective epidermal melanin. Melanin was formed from the amino acid precursor L-tyrosine within specialized cells, the melanocytes. Oxidative stress has been suggested to be the initial pathogenetic event in melanocyte degeneration with H(2)O(2) accumulation in the epidermis of patients with active disease. Auto immunity has been also suggested as another hypothesis in the pathogenesis of depigmentation disorders. Topical corticosteroids and phototherapy as common treatment modalities have been prescribed in patients with vitiligo. However, they are often not effective and safe (epidermal atrophy). Therefore, research for alternative therapies continues. AIMS: To evaluate the beneficial effects of a supplementation with antioxidant vitamins (A, C, E) and minerals (zinc, selenium) for vitiligo treatment. METHODS: Forty experimental autoimmune vitiligo mice C57BL6, aged from 5 to 12 months showing visible signs of induced vitiligo, were sequentially randomized into five parallel groups (8 mice per group). Each group mice was allocated an identical pre coded cage. the first group (SZV) received the ED + 1,4 g zinc (Zn) + 0.04 g selenium (Se) + vitamins (A 118 UI, C 8,5 mg, E 5,4 UI) /kg diet, the second group (PSZV) received the ED + 1,4 g zinc (Zn) + 0.04 g selenium (Se) + vitamins (A 118 UI, C 8.5 mg, E 5,4 UI)/kg diet + Polyphenol orally, the group 3 (PSZ) received the ED + green tea decoction prepared from 100 g/l (polyphenol orally) + 1,4 g Zn + 0.04 g Se, the 4 (P) received the ED + green tea decoction prepared green tea decoction prepared from 100 g/l, the control group 5(C) received the ED + distilled water. Cure was defined as repigmentation of treated sites. Photographic and optical techniques were used both at the baseline and on weekly basis. RESULTS: By the end of the study, mice showed visible repigmentation. Using the investigator's global assessment, therapeutic success in terms of a clear repigmentation documented in 70% of treated mice. CONCLUSION: Our findings suggest that an antioxidant supplementation is significantly beneficial in contributing superior clinical efficacy to cure vitiligo.

Study of total antioxidant status and glutathione peroxidase activity in Tunisian vitiligo patients.

BACKGROUND: Vitiligo affects one to two percent of the word population. Its pathogenesis has not been clarified yet. Multiple mechanisms such as autoimmune, neuronal, endocrine and oxidative stress resulting from unbalanced antioxidant defense system have been proposed. AIMS: Our purpose was to study the total antioxidant status and glutathione peroxidase activity in Tunisian vitiligo patients with or without diabetes or dysthyroidism. MATERIALS AND METHODS: We studied 60 vitiligo patients and 62 healthy controls. The sex ratio male/female in vitiligo patients was (27/33 = 0.81). Patients with vitiligo were divided into three groups, according to the association with diabetes or dysthyroidism. The total antioxidant status (TAS), glutathione peroxidase activity (GPX activity) was evaluated by adaptable methods using Kits. RESULTS AND CONCLUSION: The generalized vitiligo was the most frequent type (35 patients versus 25 of focal ones). All patients having vitiligo showed low levels of TAS: 0.85 +/- 0.7 and low GPX activity: 45 +/- 0.6, as compared to the control group: 1.40 +/- 0.12 mmol/L; 49 +/- 1.8 U/L, (p < 0.01), for TAS and GPX, respectively. The association of low TAS and GPX activities was more pronounced in diabetic vitiligo patients than in dysthyroid vitiligo patients. This study demonstrated that antioxidant processes depletion (low TAS and low GPX activity) is clearly involved with vitiligo in Tunisian patients, regardless of the association of the disease with diabetes or dysthyroidism.

Oxidative stress in experimental vitiligo C57BL/6 mice.

AIM: To evaluate whether oxidative stress is implicated in melanocyte damage in vitiligo. BACKGROUND: Vitiligo is a complex disorder characterized by gradually enlarging areas of depigmentation. A new unifying hypothesis for the etiology of this pigment disorder is proposed, in which we postulate that the final destruction of melanocytes in vitiligo results from a cascade of reactions initiated by a disregulation of melanogenesis, as the result of a breakdown in free radical defense. METHODS: We evaluated 18 vitiligo mice and 12 controls that were age matched. Parameters of oxidative stress such as catalase (CAT), superoxide dismutase (SOD), and plasma malondialdehyde (MDA) were measured by spectrophotometry. RESULTS: MDA levels in vitiligo mice were significantly higher than in controls (P < 0.001). CAT, SOD, and glutathione peroxidase (GPx) activities in mice were significantly lower than controls (P < 0.05 and P < 0.001, respectively). CONCLUSION: Our results confirmed that oxidative stress plays an important role in the pathogenesis of vitiligo. Melanocyte damage in vitiligo might be linked to generalized oxidative stress. This study is the first report on antioxidant parameters in experimental vitiligo mice.

Profile of vitiligo in the south of Tunisia.

BACKGROUND: Vitiligo is a depigmentation disorder characterized by the loss of melanocytes from cutaneous cells. Its pathogenesis has not yet been clarified. OBJECTIVE: To study the epidemiologic profile of vitiligo in Tunisia and analyze its characteristics. METHODS: The clinical presentation of vitiligo was examined in 60 patients [27 males (45%) and 33 females (55%)] attending the Médenine Hospital Center, a large hospital in the south of Tunisia. RESULTS: The lower limbs were the initial site of onset of vitiligo in the majority of patients (29.8%), followed by the upper limbs, head and neck, trunk, and mucosae. The most common clinical pattern observed was vitiligo vulgaris, followed by focal, acrofacial, mucosal, segmental, and universal types. Leukotrichia was observed in 23%, koebnerization in 18.5%, and a positive family history in 18%. CONCLUSION: This study indicates that vitiligo vulgaris is the most common clinical type observed in the south of Tunisia. There were associated endocrine disorders in some patients, including diabetes, hypothyroidism, and alopecia.

Both aluminum and polyphenols in green tea decoction (Camellia sinensis) affect iron status and hematological parameters in rats.

BACKGROUND: Green tea leaves naturally contain high levels of polyphenols and aluminum (Al). Polyphenols in green tea decoction are considered to be one of the major factors responsible of low iron status. However, the effects of Al from green tea decoction on iron status and hematological parameters remained unclear. AIM OF THE STUDY: The objective was to investigate the Al absorption from green tea decoction and studied its influence on iron status and hematological parameters in rats. METHODS: During the experiment period, rats were given the experimental diet + a simple dose of Al sulfate with or without graded doses of green tea decoction (25, 50 and 100 g/l). The Al absorption was evaluated in the serum; however, iron status was evaluated by the iron concentration in the liver, kidney, spleen and femur. In addition, the hemoglobin and hematocrit were evaluated. RESULTS: Our results showed that the serum Al significantly increased between 61.5 and 342%, as tea doses-dependant. The Al sulfate significantly decreased the reserve of iron in all studied organs between 21.7 and 17% (P < 0.05). In groups receiving green tea decoction alone or Al + graded doses of tea, the reserve of iron significantly decreased in all studied organs between 59.4 and 18.5% (P < 0.01). Al alone or associated with drinking doses of tea significantly decreased hemoglobin concentration between 23.6 and 9% (P < 0.05) and hematocrit between 12.7 and 7% (P < 0.01). CONCLUSION: Our data showed that Al from green tea decoction was more absorbed in the serum than Al sulfate. Al absorption was associated with low iron status and reduction of hemoglobin and hematocrit. Considering that Al competes with iron in different stage of erythropoiesis including transferrin binding, so we could assume that the negative effect of tea on iron status arises not only from polyphenols iron complexes but also from Al released in tea decoction.

Artemisia herba-alba Asso (Asteraceae) has equivalent effects to green and black tea decoctions on antioxidant processes and some metabolic parameters in rats.

AIMS: The objective was to compare the long-term effects of Artemisia herba-alba Asso decoction with a green or black tea decoction, prepared without sugar, on the antioxidant processes in rats. METHODS: The direct parameters used in the control of antioxidant processes were total antioxidant status, glutathione peroxidase activity and conjugated dienes, as early markers of lipid peroxidation. However, the indirect parameters used in this control were the body weight gains, plasma glucose and lipid concentrations, iron, copper and zinc status. RESULTS: After 9 weeks, artemisia or tea decoctions did not influence the daily food intake of the groups; however, they significantly decreased the weight gains. They significantly increased the total antioxidant status between 83.5 and 111% and the whole blood glutathione peroxidase activity between 23 and 38%. However, only the green tea and artemisia decoctions significantly decreased the plasma conjugated diene levels by 35 and 55.5%, respectively. Regarding the trace element status, artemisia, green or black tea decoctions significantly reduced the blood Fe by 28, 30 and 17%, respectively. Also, liver Fe tended to be lower in all treated groups as compared to the control group. In contrast, artemisia significantly increased both blood and liver Cu by 50 and 28% as compared to the control group. Moreover, they significantly decreased the plasma glucose and triglyceride levels between 29 and 40%. For the cholesterol, only the artemisia decoction significantly reduced the total blood cholesterol by 17%. CONCLUSION: Artemisia as well as green tea decoctions increased the total antioxidant status, whole blood glutathione peroxidase activity and zinc and copper status, and prevented weight gains and increases in conjugated dienes, plasma glucose, lipids and iron status. The beneficial antioxidant effects were in descending order: artemisia decoction > or = green tea decoction > black tea decoction. So, artemisia could constitute a good adjuvant to combat obesity, hyperglycemia, hypertriglyceridemia, hypercholesterolemia and particularly oxidative stress.

Comparative effects of the addition of mutton or beef to a bean seed ragout on iron status in growing rats.

AIMS: The objective was to compare the effects of the addition of mutton or beef to a bean seed ragout (BSR) on iron status in growing rats. In addition, we have studied the possible interference of fat from mutton on iron status because this type of animal contains a high amount of subcutaneous fat. METHODS: The iron status was investigated through the exploration of the total iron in the blood and the reserve of iron stored in the liver, spleen, intestine, heart and tibia. RESULTS: Our findings showed that the iron concentration in the total blood significantly increased in the BSR + beef (reference group), an increase of 23% (p < 0.008) as compared to the control group (BSR). However, it significantly decreased in BSR + mutton and BSR + mutton fat groups by 23% and 30%, respectively. The reserve of iron stored in the liver and intestine significantly increased only in the BSR + beef group by 69.5% and 120% (p < 0.01), respectively. Therefore, this reserve was lower in the BSR + mutton or mutton fat groups than BSR + beef group. The iron content in the tibia significantly increased only in the BSR + beef group, an increase of 88% (p < 0.05). However, it was unchanged or decreased in the BSR + mutton and mutton fat groups as compared to the control group. Only, the reserve of iron stored in the spleen significantly increased in all groups. In the heart, our results demonstrated no significant increase of the iron level among all the groups. CONCLUSION: This preliminary study suggested that mutton, in contrast to beef, has a small or negative effect on the iron status. This negative effect might be related to the high fat, especially polyunsaturated fatty acids content in mutton.

[Evaluation of the iron bioavailability from meals prepared with lentil (Lens esculenta) or with white kidney bean seeds (Phaseolus vulgaris) in anemic rats]. / Evaluation de la biodisponibilite du fer fourni par des repas a base des lentilles (Lens esculenta) ou des haricots (Phaseolus vulgaris) chez le rat anemique.

The aim of our study was to evaluate the iron bioavailability from lentil seeds and white kidney bean seeds. The iron bioavailability from diets was measured in rat by the depletion-repletion hemoglobin method and the reserve of iron stored in the liver. Our results showed that the iron bioavailability from meal based on cooked lentil seeds was significantly low (3.9 +/- 0.9%) as compared to the reference group fed with ferrous sulfate (20.4 +/- 4.9%) (p < 0.01) or to the group fed with cooked white kidney bean seeds (14.3 +/- 2.4%) (p < 0.01). Moreover, the reserve of iron stored in the liver was significantly low in rats fed with cooked lentil seeds (80.4 microg) compared to the reference group or to the group fed with cooked white kidney bean seeds (99 microg in the two groups, p < 0.01).

Effect of green tea decoction on long-term iron, zinc and selenium status of rats.

AIMS: The objective was to examine the effect of green tea decoction given at two different concentrations on the long-term (6 weeks) iron, zinc and selenium status of rats. METHODS: During the experimental period, the rats were given ad libitum a basic diet + ultra pure water (control group), a basic diet + green tea decoction prepared from 50 g/l (tea 50 group), or a basic diet + green tea decoction prepared from 100 g/l (tea 100 group). The zinc and iron status was evaluated by determining their concentrations in the serum, blood precipitate, liver, spleen, femur, heart and kidney. Selenium status was evaluated by the serum selenium concentration and whole blood glutathione peroxidase activity. RESULTS: Green tea decoction significantly reduced serum iron by 26% in the tea groups (p < 0.01). The blood precipitate of iron was significantly decreased by 25 and 41% in the tea 50 and tea 100 groups (p < 0.01), respectively. The reserve of iron stored in the liver, spleen and femur was significantly reduced in the tea 100 group by 32% (p < 0.02), 20% (p < 0.04) and 35% (p < 0.005), respectively. Moreover, the two concentrations of green tea significantly decreased the reserve of iron stored in the kidney (p < 0.005) and heart (p < 0.02). In contrast with its effects on iron status, green tea decoction significantly increased the serum zinc in the tea 100 group by 24% (p < 0.001). It also increased the blood precipitate of zinc by 50 (p < 0.01) and 75% (p < 0.0001) in tea 50 and tea 100 groups, respectively. In the kidney, heart and femur, zinc significantly increased in the tea groups dependent on the tea dose. Similarly, the high concentration of green tea decoction significantly increased the serum selenium concentration by 16% (p < 0.004). In addition, both concentrations of green tea decoction significantly increased the whole blood glutathione peroxidase activity by 102 and 130% (p < 0.01). CONCLUSION: Green tea decoction reduced the iron status and improved the zinc and selenium status of rats. These effects may constitute another beneficial effect of the green tea decoction which could play an important role in the antioxidant processes.

Iron bioavailability and weight gains to iron-deficient rats fed a commonly consumed Tunisian meal 'bean seeds ragout' with or without beef and with green or black tea decoction.

The Fe bioavailability and the weight gains were evaluated in rats fed a commonly consumed Tunisian meal 'bean seeds ragout' (BSR), with or without beef and with black or green tea decoction. The Fe bioavailability was evaluated in Fe-deficient rats by the hemoglobin repletion method and the Fe stored in the liver. The addition of beef to the BSR significantly increased the Fe bioavailability from this meal by 147% and the reserve of Fe stored in the liver by 77% (P < 0.001). In contrast, both black and green tea decoctions caused a significant decrease of the Fe bioavailability from BSR meal (-19.6 +/- 4.9% and -14.9 +/- 4.1%, respectively). The reserve of Fe stored in the liver was significantly lower in the BSR, the black and the green tea groups than in the positive control group (FeSO4). The weight gains were significantly lower in the black and the green tea groups (3.9 +/- 5.7 g, 13 +/- 1.9 g, respectively) than in the BSR group (24.9 +/- 6 g). The addition of beef to BSR meal counteracted the inhibitory effect of the kidney bean and considerably improved the Fe bioavailability and the Fe stored in the liver of rats. The green tea decoction, which constitutes an important source of antioxidant factors, had the same inhibitory effect as the black tea decoction on the Fe bioavailability from BSR meal. In addition, both black and green teas significantly reduced the weight gains, where the black tea decoction has the most effect.