Antiobesity and Hypolipidemic Potential of Nitraria retusa Extract in Overweight/Obese Women: A Randomized, Double-Blind, Placebo-Controlled Pilot Study

This study aimed to assess the efficacy of Nitraria retusa extract (NRE) in reducing weight, body mass index (BMI), body fat composition (BF), and anthropometric parameters among overweight/obese women, comparing the results with those of a placebo group. Overweight/obese individuals participated in a 12-week, double-blind, randomized, placebo-controlled trial. Body weight, BMI, body composition, and anthropometric parameters were assessed. Additionally, lipid profile and safety evaluation parameters were evaluated. Compared to the placebo group, the NRE group exhibited a mean weight loss difference of 2.27 kg (p < 0.001) at the trial's conclusion. Interestingly, the most significant weight reduction, amounting to 3.34 kg ± 0.93, was observed in younger participants with a BMI > 30.0. Similarly, BMI and BF% significantly decreased in the NRE group, contrary to the placebo group (p = 0.008 and p = 0.005, respectively). The percentage of body water (BW) (p = 0.006) as well as the ratio of LBM/BF (p = 0.039) showed a significant increase after the NRE intervention compared to the placebo. After age adjustment, all variables, except LBM/BF, retained statistical significance. Additionally, all anthropometric parameters were significantly reduced only in the NRE group. Most importantly, a significant reduction in Triglyceride (TG) levels in the NRE group was revealed, in contrast to the placebo group (p = 0.011), and the significance was still observed after age adjustment (p = 0.016). No side effects or adverse changes in kidney and liver function tests were observed in both groups. In conclusion, NRE demonstrated potent antiobesity effects, suggesting that NRE supplementation may represent an effective alternative for treating obesity compared to antiobesity synthetic drugs.

Exploring the Effects of Short-Term Daily Intake of Nitraria retusa Tea on Lipid Profile: A Pre-Post, Uncontrolled Pilot Study in Both Healthy and Overweight/Obese Adults

In the present study, we aimed to explore the feasibility, compliance, and potential benefits of Nitraria retusa extract (NRE) intervention in both healthy (BMI ≤ 24.9 Kg/m2) and overweight/obese adults (BMI > 25 Kg/m2). A total of 98 participants, including 37 healthy individuals and 61 overweight/obese adults, were randomly assigned to either a low-dose (500 mg/day) or a high-dose (2000 mg/day) NRE intervention group. Plasma lipid biomarkers, liver and kidney functions, general hematology, and blood glucose levels were measured at the baseline and 10 days after intervention. While the lipid profile of the healthy participants did not show any statistically significant changes, the obese participants in the high-dose group experienced a significant decrease in triglyceride levels (within-group difference p value = 0.004) and an increase in HDL levels (within-group p value < 0.001). No significant differences were observed in other parameters, indicating that NRE at the given doses was safe. Furthermore, the study had impressive compliance and acceptability, with over 90% of participants completing the intervention and diligently following the study protocol. This pilot study represents the first investigation into the feasibility, acceptability, and potential benefits of NRE intervention on lipid profiles in human volunteers.

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa)

Introduction

neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment.

Methods

a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency.

Results

the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene B(a)P were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8µg/g and 1.7 to 4.6µg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk.

Conclusion

neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use.

Tissue quantification of radioiodine thyroid uptake in humans by an isotopic imaging technique on slides

BACKGROUND

Thyroid metabolism involves iodine, which allows us to use radioactive iodine for diagnostic and therapy purposes. The efficiency of radioiodine therapy depends on several parameters; the ability of thyroid tissue to uptake radioactive iodine is one of them.

OBJECTIVE

The objective of this work is to quantify the radioactive iodine uptake on thyroid tissue.

METHODS

In this work, we developed a method to quantify the in vivo uptake of iodine-131 on sections of thyroid glands removed by thyroidectomies. We performed an analysis of histological sections of the thyroid tissue by beta imaging. We had the opportunity to quantify the fixed radioactivity and to analyze its distribution in the thyroid gland, thanks to the good spatial resolution available with the type of detector used.

RESULTS

The results gave a high image resolution showing the heterogeneity of iodine-131 fixation by the thyroid tissue. We were able to quantify the tissue radioactivity in mega Becquerel (MBq) per volume unit.

CONCLUSION

This work has shown that the direct quantification of the thyroid tissue uptake is possible using the beta imaging system.

Rosemary Tea Consumption Alters Peripheral Anxiety and Depression Biomarkers: A Pilot Study in Limited Healthy Volunteers

Background: Rosmarinus officinalis L.is traditionally used as an infusion in the treatment of several diseases and in particular against neuropsychiatric disorders, such as anxiety and depression. It was established that rosemary extracts show an antidepressant effect on animal models. However, to the best of our knowledge, there is no scientific data that highlights the therapeutic effects of rosemary intake on human mental health.Aim:This study investigated whether rosemary tea consumption affects the plasma levels of anxiety and depression biomarkers in healthy volunteers.Methods:Twenty-two healthy volunteers aged between 20 and 50 years old consumed rosemary tea prepared from 5 g of dried rosemary in 100 mL boiled water once a day for 10 days. Plasma concentrations of Brain-Derived Neurotrophic Factor (BDNF), Interleukine-6 (IL-6), Interleukine-4 (IL-4), Tumor Necrosis Factor- alpha (TNF-α), Interferon-gamma (IFNϒ), and cortisol were measured by enzyme-linked immunosorbent assay using commercial ELISA kits (R&D systems) before rosemary consumption and at the end of the experiment.Results:Rosemary tea consumption significantly increased the concentration of BDNF([BDNF]D0 = 22363.86 ± 12987.66 pg/mL, [BDNF]D10 = 41803.64 ± 28109.19, p = 0.006) and TNF-α([TNF-α] D0 = 39.49 ± 14.44 pg/mL, [TNF-α] D10 = 56.24 ± 39.01, p = 0.016). However, a slight variation that was statistically non-significant in INFϒ, cortisol, IL-4, IL-6 levels and in the ratio IL-4/INFϒ was observed (p > 0.05).Conclusion:Our findings highlight the promising anxiolytic and/or antidepressant effects of rosemary tea consumption in healthy volunteers since it increases the level of the most reliable depression biomarker BDNF. However, more powerful studies with larger sample size, carefully-chosen target population and, an extended intervention period are required.

GC-MS Based Metabolic Profiling of Parkinson's Disease with Glutathione S-transferase M1 and T1 Polymorphism in Tunisian Patients

AIM AND OBJECTIVE

Parkinson's disease (PD) is the second most common neurodegenerative disease. It is a multifactorial disorder (caused by aging, environmental, and genetic factors). Metabolomics can help explore the biomarker profiles for aging. Recent studies showed an association between the glutathione S-transferases (GSTs) polymorphisms and PD risk. The purpose of this study was to evaluate the association of this genetic polymorphism and the metabolomic profile in PD Tunisian patients, in order to identify effective biomarkers in the genetic differentiation.

MATERIALS AND METHODS

In this study, the metabolomic profile changes related to GSTs polymorphism were searched in 54 Tunisian PD patients treated with L-dopa, using a gas chromatography-mass spectrometry (GC-MS) technique.

RESULTS

The study results showed that mannose, methyl stearate, and three other unknown metabolites, increased in patients with GSTM1 positive genotype, while glycolic acid, porphine, monomethyl phosphate, fumaric acid, and three other unknown metabolites decreased in patients with GSTM1 positive genotype. Subsequently, the levels of glycolic acid, erythronic acid, lactic acid, citric acid, fructose, stearic acid, 2-amino-2-methyl-1,3-propanediol and three other unknown metabolites increased in patients with GSTM1 positive genotype, while the levels of proline, valine and two unknown metabolites decreased with GSTT1 positive genotype.

CONCLUSION

All these altered metabolites are related to energy metabolism and it can be concluded that GSTs polymorphism based the shifting in energy metabolism and led to oxidative stress.

Effects of glutathione S-transferase M1 and T1 deletions on Parkinson's disease risk among a North African population

PURPOSE

In this study, the effects of glutathione S-transferase polymorphisms Mu1 (GSTM1) and glutathione S-transferase polymorphisms Theta1 (GSTT1) on Parkinson's disease (PD) risk factor were evaluated in a Tunisian population.

METHODS

These polymorphisms were analyzed in 229 healthy Tunisian subjects and 64 Tunisian patients with PD, using a polymerase chain reaction (PCR). Statistical analysis was performed using SPSS 18.0. The relative associations between the GST genotypes and PD were assessed by calculating the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The study results demonstrated that the individuals with GSTM1 [OR=3.93, 95% CI: 1.98-7.92, P=10^-6] and GSTT1 [OR=5.45, 95% CI: 2.90-10.30, p=10^-6] were statistically associated with the risk of PD. A significant association was also found between the individuals with both GSTM1/T1 null genotypes and PD risk [OR=22.10, 95% CI: 6.99-73.75, P=10^-6].

CONCLUSION

These genotyping findings suggest that the absence of both GSTM1 and GSTT1 activity could be a contributory factor for the development of PD.

Evaluation of Daily Laurus nobilis Tea Consumption on Lipid Profile Biomarkers in Healthy Volunteers

Introduction: Laurus nobilis is known in the field of herbal medicine and in vitro studies that it has beneficial effects such as antibacterial, antifungal, antidiabetes, and anti-inflammatory properties.Objective: We investigated whether L. nobilis tea consumption affects the plasma levels of lipid biomarkers in healthy volunteers.Methods: Thirty healthy Tunisian volunteers aged between 20 and 57 years old consumed L. nobilis infusion, prepared from 5 g of dried L. nobilis leaves in 100 ml boiled water, once a day during 10 days. Plasma concentrations of serum low-density lipoprotein (LDL) cholesterol, triglycerides and HDL (high-density lipoprotein) cholesterol were measured by Beckman Coulter D × 600 analyzer before L. nobilis consumption and at the end of the experiment.Results: L. nobilis tea consumption significantly increased the concentration of HDL cholesterol ([HDL cholesterol] D₀ = 1.34 ± 0.25 pg/mL, D₁₁=1.42 ± 0.29, p = 0.01). However, a slight decrease that was statistically non-significant in LDL cholesterol and triglycerides levels was observed (p < 0.05).Conclusions: These findings highlight the improving blood lipidic profiles, which means a possible positive effect on reducing the risk of cardiovascular disease of L. nobilis tea consumption in healthy volunteers. However, more powerful studies with an extended treatment period are required.

Bioavailability and metabolism of rosemary infusion polyphenols using Caco-2 and HepG2 cell model systems

BACKGROUND

Rosmarinus officinalis is an aromatic plant used in folk medicine as a result of the therapeutic properties associated with its phenolic composition, being rich in rosmarinic acid (RA) and caffeic acid (CA). To better understand the bioactivity of these compounds, their absorption and metabolism were assessed in human Caco-2 and HepG2 cells, as small intestine and liver models, respectively, using RA and CA standards, as well as a rosemary infusion and ferulic acid (FA).

RESULTS

Test compounds were partially up-taken and metabolized by Caco-2 and HepG2 cells, although a higher metabolization rate was observed after hepatic incubation compared to intestinal incubation. CA was the compound best absorbed followed by RA and FA, showing metabolites percentages of 30.4%, 11.8% and 4.4% in Caco-2 and 34.3%, 10.3% and 3.2% in HepG2 cells, respectively. RA in the rosemary infusion showed improved bioavailability compared to pure RA. Methyl derivatives were the main metabolites detected for CA and RA after intestinal and hepatic metabolism, followed by methyl-glucuronidates and glucuronidates. RA was also minimally hydrolyzed into CA, whereas FA only was glucuronidated. Rosemary polyphenols followed the same biotransformation pathways as the standards. In addition, phase II derivatives of luteolin were observed.

CONCLUSION

Rosemary polyphenols are partially metabolized in both the intestine and liver. © 2018 Society of Chemical Industry.

Glutathione S-transferase M1 and T1 polymorphisms and the risk of mild hepatotoxicity induced by carbamazepine in a tunisian population study

BACKGROUND

The aim of this study was to evaluate whether the glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) null alleles may contribute to carbamazepine-induced hepatotoxicity.

METHODS

A cross-sectional prospective study was conducted to identify the frequency distribution of GSTM1 and GSTT1 alleles in 129 Tunisian epileptic patients treated with carbamazepine. Null alleles were determined using a Polymerase Chain Reaction. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by standard methods.

RESULTS

Our results showed that the frequencies of GSTM1 (-) null allele and GSTT1 null (-) allele were 74.4 and 17.8% respectively. The ALT and AST levels were elevated in 46 (35.7%) and 33 (25.6%) cases. The mean values of ALT and AST were approximately 1.32 and 3.61 times higher than the upper limit of normal levels, respectively. The values of ALT and AST were significantly higher in GSTM1 (-) allele than in GSTM1 (+) (p = 10^-3.and 0.004, respectively). The level of ALT was significantly higher in combination of GSTM1 (-)/T1(-) than in combined GSTM1(-)/T1(+) and combined GSTM1(+)/T1(+) (p = 0.2 and 0.03, respectively), and that of AST was significantly higher in combination of GSTM1(-)/T1(-) and in combination of GSTM1(+)/T1(-) than in combination of GSTM1(+)/T1(+) (p = 10^-3 and 10^-3, respectively).

CONCLUSIONS

Our findings suggest that the GSTM1 (-) allele may be considered as a key factor for the development of carbamazepine-induced hepatotoxicity. Results related to GSTT (-) allele and elevation in AST levels should be considered with caution as AST may be elevated in other pathophysiological conditions.

A Comprehensive Characterisation of Rosemary tea Obtained from Rosmarinus officinalis L. Collected in a sub-Humid Area of Tunisia

INTRODUCTION

Rosemary (Rosmarinus officinalis L.) is an aromatic plant common in Tunisia and it is widely consumed as a tea in traditional cuisine and in folk medicine to treat various illnesses. Currently, most research efforts have been focused on rosemary essential oil, alcoholic and aqueous extracts, however, little is reported on rosemary infusion composition.

OBJECTIVE

To investigate compounds present in rosemary tea obtained from Rosmarinus officinalis L. collected in a sub-humid area of Tunisia in order to assess whether the traditional rosemary tea preparation method could be considered as a reference method for rosemary's compounds extraction.

METHODOLOGY

Qualitative characterisation of Rosmarinus officinalis tea obtained after rosemary infusion in boiled water was determined by high performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS). Quantitative analysis relies on high performance liquid chromatography with diode array detector (HPLC-DAD).

RESULTS

Forty-nine compounds belonging to six families, namely flavonoids, phenolic acids, phenolic terpenes, jasmonate, phenolic glycosides, and lignans were identified. To the best of the authors' knowledge eucommin A is characterised for the first time in rosemary. Rosmarinic acid (158.13 μg/g dried rosemary) was the main compound followed then by feruloylnepitrin (100.87 μg/g) and luteolin-3'-O-(2″-O-acetyl)-β-d-glucuronide (44.04 μg/g). Among quantified compounds, luteolin-7-O-rutinoside was the compound with the lowest concentration.

CONCLUSION

The infusion method allows several polyphenols present in rosemary tea to be extracted, therefore it could be a reference method for rosemary's compounds extraction. Moreover, traditional Tunisian Rosmarinus officinalis tea consumption is of interest for its rich phenolic content. Copyright © 2017 John Wiley & Sons, Ltd.

Effects of EPHX1 and CYP3A4*22 genetic polymorphisms on carbamazepine metabolism and drug response among Tunisian epileptic patients

The aim of this study was to evaluate the impact of polymorphisms in the EPHX1 (c.416A > G, c.337T > C) and CYP3A4*22 genes involved in carbamazepine (CBZ) metabolism and pharmacoresistance among 118 Tunisian patients with epilepsy under maintenance dose of CBZ. These genetic polymorphisms were analyzed by PCR-RFLP. Associations between plasma CBZ concentration, CBZ-E concentration, maintenance doses and metabolic ratio (CBZ-E:CBZ, CBZ-D:CBZ-E) were analyzed with each polymorphism. Both variants of EPHX1 c.416A > G and c.337T > C are significantly associated with higher metabolic ratio CBZ-E:CBZ and seem to decrease the activity of the epoxide hydrolase. The CYP3A4*22 variant allele is significantly associated with lower CBZ-D:CBZ-E ratio and seems also to be associated with less activity of the cytochrome. Our data suggest that certain polymorphisms of metabolizing enzyme genes could influence inter-individual variability of CBZ metabolism.

The relationship between pharmacokinetic parameters of carbamazepine and therapeutic response in epileptic patients

INTRODUCTION

The prescribed dose and carbamazepine plasma concentration to achieve the optimal therapeutic efficacy are highly variable from one patient to the other. Our study aimed to determine whether biological parameters may be used as plasma markers that can individually adjust the carbamazepine dose necessary to optimize therapeutic efficacy.

MATERIAL AND METHODS

Ninety-four epileptic patients under carbamazepine monotherapy and who have never used combination therapy were recruited from the consecutive admissions at the Department of Neurology "CHU Sahloul" of Sousse Central Hospital in Tunisia from February 2010 to April 2011. The patients were monitored for epilepsy for three years on average. Carbamazepine and 10,11-epoxide-carbamazepine concentrations were analyzed through high-performance liquid chromatography. Simultaneously, therapeutic efficacy was assessed through the annual number of seizures in each patient.

RESULTS

Our results showed the absence of any significant correlations between specific dose (mg/kg/day), carbamazepine plasma concentrations and therapeutic efficacy (r = 0.0025, p = 0.30; r = 0.1584, p = 0.38 respectively), whereas both plasma 10,11-epoxide-carbamazepine concentration and 10,11-epoxide-carbamazepine to plasma carbamazepine ratio were closely correlated with therapeutic efficacy (r = 0.34, p = 0.03; r = 0.45, p = 0.008 respectively). The optimum therapeutic response was observed among patients who simultaneously had a plasma concentration of 0.8 μg/ml of metabolite and 5.5 μg/ml of carbamazepine.

CONCLUSIONS

The results suggest that plasma levels of both carbamazepine and of 10,11-epoxide-carbamazepine must be set to achieve an optimum therapeutic response.

Implications of metabolic parameters of carbamazepine in the therapeutic monitoring of Tunisian patients with epilepsy

Carbamazepine (CBZ) is widely used in the control of simple and complex focal seizures and generalized tonic-clonic seizures in patients with epilepsy. The toxic effects of CBZ are not easily predicted, and this is due to the difficulty of delivering the optimal dose and/or plasma concentration of CBZ necessary to achieve beneficial effects, and especially to prevent the onset of toxicity associated with its use. Our study aimed to determine the relationship between the administered daily dose of CBZ and its pharmacokinetic parameters, including concentrations of CBZ and carbamazepine-10,11-epoxide (CBZ-E) plasma levels, and the metabolic ratio of CBZ-E to CBZ, in Tunisian patients with epilepsy. To accomplish this, a high-performance liquid chromatography method with ultraviolet detection was used for quantification in the simultaneous analysis of CBZ and one of its active metabolites, CBZ-E, in human plasma. A statistically significant positive correlation was found between the daily doses administered (mg/kg/day) and plasma concentrations of CBZ and CBZ-E, and the CBZ-E/CBZ ratio increased significantly as a function of the specific dose (in mg/kg/day). The increase in plasma concentrations of CBZ-E was non-linear in relation to plasma concentrations of CBZ, and there was no correlation between the CBZ-E/CBZ metabolic ratio and CBZ plasma concentrations. Our findings suggest that monitoring of CBZ as well as CBZ-E blood levels should be considered, as it may play a useful role in the therapeutic management of patients with epilepsy.

Effects of glutathione S-transferase M1 and T1 deletions on epilepsy risk among a Tunisian population

Glutathione-S-transferases enzymes are involved in the detoxification of several endogenous and exogenous substances. In this present study, we evaluated the effects of two glutathione-S-transferase polymorphisms, (GSTM1 and GSTT1) on epilepsy risk susceptibility in a Tunisian population. These polymorphisms were analyzed in 229 healthy subjects and 98 patients with epilepsy, using a polymerase chain reaction (PCR). Odds ratio (ORs) was used for analyzing results. The study results demonstrated that individuals with the GSTM1 null genotype were at an increased risk of developing epilepsy [OR=3.80, 95% confidence interval (CI) (2.15-4.78)], whereas no significant effects were observed between individuals with GSTT1 null genotype and epilepsy risk [OR=1.15, 95% CI (0.62-2.12)]. These genotyping finding revealed that the absence of GSTM1 activity could be contributor factor for the development of epilepsy disease.

Analysis of thiopurine S-methyltransferase phenotype-genotype in a Tunisian population with Crohn's disease

This study was conducted to investigate the thiopurine S-methyltransferase TPMT activity distribution and gene mutations in Tunisian population with positive diagnostic for Crohn's disease. TPMT activity was measured in Tunisian population (n = 88) by a high performance liquid chromatography assay. Polymerase chain reaction-based methods were used to determine the frequency of TPMT mutant alleles TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C. TPMT activity was normally distributed, ranging from 4.58 to 35.27 nmol/(h ml) RBC with a mean of 18.67 ± 7.10 nmol/(h ml) RBC. Seven TPMT*3A heterozygotes and one TPMT*3C homozygote were found in 88 patients, with allele frequencies of 0.039 and 1.13, respectively. TPMT*3A and the TPMT*3C, which cause the largest decrease in enzyme activity, were both variant alleles detected in the Tunisian population.

Role of CYP1A2 polymorphisms in breast cancer risk in women

Cytochrome P4501A2 (CYP1A2) is a key enzyme in the etiology of breast cancer (BC). It is involved in breast carcinogen activation [aromatic (AAs) and heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs)], in the production of beneficial oestrogen [2-hydroxyestrone (2-OHE1)] and in converting arachidonic acid (AAc) to epoxyeicosatrienoic acids (EETs), which have anti-inflammatory properties. Within a hospital-based case-control study, the effect of functional CYP1A2 variants [-3860G/A (rs2069514), -2467T/delT (rs3569413), -163C/A (rs762551)] and their interactions with environmental factors in BC risk was investigated. The study population included 125 BC cases and 43 non-cancer controls. Genotyping was performed in RT-PCR using Taqman assays. The gene-environment interaction was appraised using a case-only study design. We found that the -3860A variant, independently from environmental factors, as well as by interacting with fried foods (p=0.025) and indoor exposure to pollutants (p=0.050), reduced the risk of BC (p=0.025), whereas its interaction with coffee (p=0.045) increased the BC risk. This is the first study indicating that the -3860A variant, by decreasing CYP1A2 activity, modifies BC risk by interacting with environmental factors, thereby supporting the hypothesis that reduced CYP1A2 activity contributes to BC risk in different ways, for example, it may be protective by reducing the activation of pro-carcinogens such as AAs, HAs and PAHs, but would increase risk by reducing the beneficial formation of 2-OHE1 and EETs.

Polyphenol contents and antioxidant activities of extracts from flowers of two Crataegus azarolus L. varieties

Phenolic contents of the ethyl acetate extracts prepared from floral buds and opened flowers harvested on Crataegus azarolus trees native in two localities were performed. The antioxidant activity was measured by DPPH' (2,2-diphenyl-picrylhydrazyl), ABTS+ (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals scavenging using spectrophotometric method. The C. azarolus var. aronia (Willd.) Batt., producing yellow fruits, was richer in total phenols (1638.7 +/- 89.9 mg acid gallic/100 g dry weight) according to C. azarolus var. eu-azarolus Maire (1415.5 +/- 23.8 mg acid gallic/100 g dry weight), producing red ones. Ethyl acetate extract from opened flowers has less content in total phenols, proanthocyanidins and flavonoids compared to this from floral buds. Floral buds from the two C. azarolus varieties occurring in Siliana-Djebel Serdj showed the highest radical scavenging activities (2431.8 +/- 32.7 and 2267.7 +/- 22.7 micromol Trolox/100 g dry weight). Hawthorn from Tunisia contains eight antioxidants of phenolic type (chlorogenic acid, hyperoside, rutin, spiraeoside, isoquercitrin, quercetin, (-)-epicatechin and the dimer procyanidin B2). These compounds identified specially in floral bud extracts presented a strong radical-scavenging activity.

Marked differences between mutagenicity in Salmonella and tumour-initiating activities of dibenzo[a,e]fluoranthene proximate metabolites; initiation inhibiting activity of norharman

Dibenzofluoranthene-12,13-dihydrodiol (DBF-12,13-DHD) is six times more mutagenic in Salmonella TA100 than dibenzofluoranthene-3,4-dihydrodiol (DBF-3,4-DHD). However, these two major dibenzo[a,e]fluoranthene (DBF) proximate metabolites, which are immediate precursors of the corresponding diolepoxides, showed on an equimolar basis nearly identical initiation activities on mouse skin; they induced three times more papillomas than the parent hydrocarbon. On the other hand the epithelioma initiation capacities, i.e. the number of papillomas progressing to malignant tumours, of DBF or the two dibenzofluoranthene dihydrodiols were equivalent. Norharman, a putative vicinal diolepoxidation inhibitor in DBF metabolism when administered topically together with the initiation dose (100 nmol), strongly inhibited the induction of tumours by DBF-3,4-DHD and DBF. The relationship between in vitro mutagenic activity in Salmonella and the carcinogenicity of DBF metabolites in mice appears to be qualitative rather than quantitative.

Possible involvement of a vicinal, non-bay-region dihydrodiol-epoxide in the activation of dibenzo[a,e]fluoranthene into bacterial mutagens

Dibenzo[a,e]fluoranthene, its 7-hydroxy, 3,4- and 12,13-dihydrodiol metabolic derivatives as well as three synthetic, structurally related hydrocarbons, were tested for mutagenicity towards Salmonella typhimurium TA100 strain in the presence of 3-methylcholanthrene-treated rat and mouse liver post-mitochondrial supernatants. Of these compounds, the 12,13-dihydrodiol showed the highest activity, being 6-10 times more mutagenic than the parent compound. Our data, in conjunction with those of previous studies on the liver microsomal metabolism and DNA binding of dibenzo[a,e]fluoranthene and its dihydrodiols, indicate that activation of dibenzo[a,e]fluoranthene to bacterial mutagens may occur predominantly through a vicinal, non-bay-region 12,13-dihydrodiol epoxide.

Multi-step metabolism of the carcinogen dibenzo[a,e]fluoranthene. II. Metabolic pathways

The structural identification of nineteen metabolites of dibenzo[a,e]fluoranthene (DBF) obtained by incubation in rat and mouse liver microsomes, allows one to establish a qualitative and semi-quantitative metabolic chart, involving up to three distinct oxidative attacks. The primary steps lead to dihydrodiols on rings A and D and phenols on rings A and E. Secondary vicinal epoxidation of dihydrodiols is a minor route as compared to attack at a second peripheral ring. Even after a third oxidation, one of the peripheral rings A, D and E remains unsubstituted. A model for cytochrome P-450 enzymatic activity which takes into account most of the observations is proposed. It requires that the catalytic site for monooxygenation is 0.6 nm apart from the center of an hydrophobic protein site accommodating one of the unsubstituted peripheral benzenoid rings. both trans diequatorial dihydrodiols of ring A and D corresponding to the 'bay' and 'pseudo bay region'; of DBF appear in the activation pathways for the in vivo carcinogenesis. The ultimate metabolite reacting with DNA is thus, most probably, a vicinal dihydrodiol epoxide of ring A or D. The great complexity of the metabolic chart of DBF as compared to other carcinogenic polycyclic aromatic hydrocarbons leaves also the possibility of sequential reactions at these two distinct sites of the molecule.

Binding to DNA of bay region and pseudo bay region diol-epoxides of dibenzo[a,e]fluoranthene and comparison with adducts obtained with dibenzo[a,e]fluoranthene or its dihydrodiols in the presence of microsomes

When dibenzo[a,e]fluoranthene (DBF) is incubated in vitro with mouse liver microsomes in the presence of calf thymus DNA, several metabolites bind covalently to DNA. The metabolite-nucleoside adducts were separated by h.p.l.c. after enzymatic hydrolysis. The elution profile of this chromatogram exhibits six main peaks, labeled from A to F in order of decreasing polarity. It was compared to those obtained by direct reaction of DNA with 3,4-dihydroxy-1,2-epoxy 1,2,3,4-tetrahydro DBF (the bay region diol-epoxide) or 12,13-dihydroxy 10,11-epoxy 10,11,12,13-tetrahydro DBF (the pseudo bay region diol-epoxide). In both cases the retention period of the peak of the adduct was identical to that of the main peak E. The fluorescence spectra of these two adducts were similar to those of the corresponding tetrols. When DNA is reacted in the presence of microsomes with 3,4-dihydrodihydroxy DBF, the elution profile of the adducts indicates that vicinal epoxidation of the dihydrodiol and direct reaction is dominant. The metabolic reaction with 12,13-dihydrodihydroxy DBF appears more complex as revealed by the observed number of adducts which correspond to vicinal epoxidation of dihydrodiol as well as further oxidation at other sites.

Multi-step metabolism of the carcinogen dibenzo[a,e]fluoranthene. I. Identification of the metabolites from rat microsomes

The metabolism of the polycyclic hydrocarbon dibenzo[a,e]fluoranthene (DBF) has been investigated. Two new primary metabolites have been identified by proton n.m.r. as the trans diaxial dihydrodiols of the bay and of the pseudo bay regions of DBF. In addition, twelve new metabolites arising from secondary and tertiary metabolic transformations have been identified. The stereochemistry of eleven of these products has been established by proton n.m.r. spectroscopy. In contrast with other alternant carcinogenic polycyclic hydrocarbons, a vicinal diol epoxidation at the bay region of the trans diequatorial dihydrodiols is a minor reaction relative to attack at distant sites, which leads principally to phenolic derivatives of the dihydrodiols and, with a lower yield, to a bis-dihydrodiol (3,4,12,13-tetrahydro-3,4,12,13-tetrahydroxy-DBF). This offers a possibility of bifunctional metabolic activation in the carcinogenicity of DBF. A catechol of the benzanthracenic moiety of DBF has also be identified, dibenzo[a,e]fluoranthene 3,4-catechol. In summary, all three external rings of DBF can be attacked enzymatically, but apparently ring E does not undergo epoxidation while more usual trans diaxial and diequatorial dihydrodiols, as well as tetraols of rings A and D, were detected.