Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2018 ( 1 )

2016 ( 1 )

2015 ( 5 )

2014 ( 13 )

Custom range...

Search Results: 1 - 10 of 102 matches for " Boubaker Jihed "
All listed articles are free for downloading (OA Articles)
Page 1 /102
Display every page Item
Antimutagenic and free radical scavenger effects of leaf extracts from Accacia salicina
Jihed Boubaker, Hedi Mansour, Kamel Ghedira, Leila Chekir-Ghedira
Annals of Clinical Microbiology and Antimicrobials , 2011, DOI: 10.1186/1476-0711-10-37
Abstract: Antioxidant activity of A. salicina extracts was determined by the ability of each extract to protect against plasmid DNA strand scission induced by hydroxyl radicals. An assay for the ability of these extracts to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 and TA 104 strains was conducted. In addition, nonenzymatic methods were employed to evaluate anti-oxidative effects of tested extracts.These extracts from leaf parts of A. salicina showed no mutagenicity either with or without the metabolic enzyme preparation (S9). The highest protections against methylmethanesulfonate induced mutagenicity were observed with all extracts and especially chloroform extract. This extract exhibited the highest inhibitiory level of the Ames response induced by the indirect mutagen 2- aminoanthracene. All extracts exhibited the highest ability to protect plasmid DNA against hydroxyl radicals induced DNA damages. The ethyl acetate (EA) and chloroform (Chl) extracts showed with high TEAC values radical of 0.95 and 0.81 mM respectively, against the ABTS.+.The present study revealed the antimutagenic and antioxidant potenty of plant extract from Accacia salicina leaves.Exposure to genotoxic chemicals present in food, in the environment, and used in medical treatment can alter the genetic material permanently, and thus may lead cancer [1]. On the other hand, oxidative stress, caused by reactive oxygen species (ROS), is known to cause the oxidation of biomolecules, leading to cellular damage. The tissue injury caused by ROS may include DNA protein and lipids damage [2,3]. Antigenotoxic plant can counter or prevent the adverse effect caused by DNA-damaging chemicals [4]. Drugs obtained from plants have been investigated for the possible presence of mutagenic and/or carcinogenic substances, following the criteria and norms established for synthetic medicines. Fortunately, numerous defense systems protect the cellular macromolecules against oxidation. DNA repa
Polar extracts from (Tunisian) Acacia salicina Lindl. Study of the antimicrobial and antigenotoxic activities
Jihed Boubaker, Hedi Mansour, Kamel Ghedira, Leila Ghedira
BMC Complementary and Alternative Medicine , 2012, DOI: 10.1186/1472-6882-12-37
Abstract: The antimicrobial activity was tested on the Gram positive and Gram negative reference bacterial strains. The Mutagenic and antimutagenic activities against direct acting mutagens, methylmethane sulfonate (MMS) and 4-nitro-o-phenylenediamine (NOPD), and indirect acting mutagens, 2-aminoanthracene (2-AA) and benzo[a]pyrene (B(a)P) were performed with S. typhimurium TA102 and TA98 assay systems. In addition, the enzymatic and nonenzymatic methods were employed to evaluate the anti-oxidative effects of the tested extracts.A significant effect against the Gram positive and Gram negative reference bacterial strains was observed with all the extracts. The mutagenic and antimutagenic studies revealed that all the extracts decreased the mutagenicity induced by B(a)P (7.5 μg/plate), 2-AA (5 μg/plate), MMS (1.3 mg/plate) and NOPD (10 μg/plate). Likewise, all the extracts showed an important free radical scavenging activity towards the superoxide anion generated by the xanthine/xanthine oxidase assay system, as well as high Trolox Equivalent Antioxidant Capacity (TEAC), against the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)+? radical. TOF-enriched extract exhibited the highest protective effect against free radicals, direct acting-mutagen and metabolically activated S9-dependent mutagens.The present study indicates that the extracts from A. salicina leaves are a significant source of compounds with the antimutagenic and antioxidant activities, and this may be useful for developing potential chemopreventive substances.Plants are rich source of natural products used for centuries to cure various diseases. The plant-derived medicines are based upon the premise that they contain natural substances that can promote health and alleviate illness. So, a retrospection of the healing power of plants and a return to natural substances are an absolute need of our time. The demonstration of the presence of natural products, such as polyphenols, alkaloids,
Isorhamnetin 3-O-robinobioside from Nitraria retusa leaves enhance antioxidant and antigenotoxic activity in human chronic myelogenous leukemia cell line K562
Boubaker Jihed,Sghaier Mohammed,Skandrani Ines,Ghedira Kamel
BMC Complementary and Alternative Medicine , 2012, DOI: 10.1186/1472-6882-12-135
Abstract: Background In this report, the isorhamnetin 3-o-robinobioside and its original extract, the ethyl acetate extract, from Nitraria retusa leaves, were evaluated for their ability to induce antioxidant and antigenotoxic effects in human chronic myelogenous leukemia cell line. Methods Nitraria retusa products properties were carried out by firstly evaluating their effects against lipid peroxidation induced by H2O2, using the thiobarbituric acid reactive substances species (TBARS) assay, and proceeding to the assay of cellular antioxidant activity, then doing the comet assay. Results The isorhamnetin 3-o-robinobioside showed a protective effect against lipid peroxidation induced by H2O2. The same natural compound and ethyl acetate extract inhibited oxidation induced by 2,2′-azobis (2-amidinopropane) dihydrochloride in human chronic myelogenous leukemia cells with respectively 50% inhibitory concentration values of 0.225 mg/ml and 0.31 mg/ml, reflecting a significant antioxidant potential. The same two products inhibited the genotoxicity induced by hydroxyl radicals in the same human cell line (by 77.77% at a concentration of 800 μg/ml and by 80.55% at a concentration of 1000 μg/ml respectively). Conclusions The isorhamnetin 3- o-robinobioside and its original extract, the ethyl acetate extract, from Nitraria retusa leaves, have a great antioxidant and antigenotoxic potential on human chronic myelogenous leukemia cell line K562.
Antioxidant, genotoxic and antigenotoxic activities of daphne gnidium leaf extracts
Chaabane Fadwa,Boubaker Jihed,Loussaif Amira,Neffati Aicha
BMC Complementary and Alternative Medicine , 2012, DOI: 10.1186/1472-6882-12-153
Abstract: Background Plants play a significant role in maintaining human health and improving the quality of human life. They serve humans well as valuable components of food, as well as in cosmetics, dyes, and medicines. In fact, many plant extracts prepared from plants have been shown to exert biological activity in vitro and in vivo. The present study explored antioxidant and antigenotoxic effects of Daphne gnidium leaf extracts. Methods The genotoxic potential of petroleum ether, chloroform, ethyl acetate, methanol and total oligomer flavonoid (TOF) enriched extracts from leaves of Daphne gnidium, was assessed using Escherichia coli PQ37. Likewise, the antigenotoxicity of the same extracts was tested using the “SOS chromotest test”. Antioxidant activities were studied using non enzymatic and enzymatic method: NBT/Riboflavine and xantine oxidase. Results None of the different extracts produced a genotoxic effect, except TOF extract at the lowest tested dose. Our results showed that D. gnidium leaf extracts possess an antigenotoxic effect against the nitrofurantoin a mutagen of reference. Ethyl acetate and TOF extracts were the most effective in inhibiting xanthine oxidase activity. While, methanol extract was the most potent superoxide scavenger when tested with the NBT/Riboflavine assay. Conclusions The present study has demonstrated that D. gnidium leaf extract possess antioxidant and antigenotoxic effects. These activities could be ascribed to compounds like polyphenols and flavonoid. Further studies are required to isolate the active molecules.
Leaf extracts from Nitraria retusa promote cell population growth of human cancer cells by inducing apoptosis
Jihed Boubaker, Wissem Bhouri, Mohamed Sghaier, Ines Bouhlel, Ines Skandrani, Kamel Ghedira, Leila Chekir-Ghedira
Cancer Cell International , 2011, DOI: 10.1186/1475-2867-11-37
Abstract: Apoptosis of the human chronic myelogenous erythroleukaemia (K562) was evidenced by investigating DNA fragmentation, PARP cleavage and caspases 3 and 8 inducing activities, in the presence of N. retusa extracts.Our study revealed that the tested extracts from N. Retusa contain many useful bioactive compounds. They induced in a time-dependent manner the apoptosis the tested cancerous our cell line. This result was confirmed by ladder DNA fragmentation profile and PARP cleavage, as well as a release in caspase-3 and caspase-8 level.Our results indicate that the tested compounds have a significant antiproliferative effect which may be due to their involvement in the induction of the extrinsic apoptosic pathway.Apoptosis is a form of cell death in which a programmed sequence of events eliminates cells without damaging neighbouring cells. Apoptosis is triggered through either a death receptor mediated extrinsic pathway or a mitochondrial intrinsic pathway. Phytotherapy is considered as an alternative, to mitigate side effects due the indiscriminate use of synthetic drugs. For many years, the antiproliferative actions of chemotherapeutic drugs were ascribed solely to their ability to induce genotoxic damage [1]. Therefore, the role of plant derived polyphenols in chemoprevention of cancer has emerged as an interesting area of research. To date, many anticancer drugs have been developed and applied by clinical doctors [2]. In addition flavonoids have been shown to cause apoptosis through induction of Bax with concomitant suppression of Bcl-2, or through other molecules and pathways including up-regulation of death receptor 5, modulation of IGFBP-3, involvement of p38-MAPK, and inhibition of PI-3-kinase/Akt and ERK pathways [3]. In our case, we were interested with leaf extracts from Nitraria retusa in order to investigate an alternative phytoterapy solution to current anticancerous treatments. Its fleshy red fruits are eaten by humans and are used to prepare drinks. The le
Investigation of the apoptotic way induced by digallic acid in human lymphoblastoid TK6 cells
Wissem Bhouri, Jihed Boubaker, Ines Skandrani, Kamel Ghedira, Leila Chekir Ghedira
Cancer Cell International , 2012, DOI: 10.1186/1475-2867-12-26
Abstract: We attempt to characterize the apoptotic pathway activated by DGA. Apoptosis was detected by DNA fragmentation, PARP cleavage and by evaluating caspase activities.The inhibition of lymphoblastoid cell proliferation was noted from 8.5?μg/ml of DGA. The induction of apoptosis was confirmed by DNA fragmentation and PARP cleavage. We have demonstrated that DGA induces apoptosis by activating the caspase-8 extrinsic pathway. Caspase-3 was also activated in a dose dependent manner.In summary, DGA exhibited an apoptosis inductor effect in TK6 cells revealing thus its potential as a cancer-preventive agent.Polyphenols were described to be beneficial against human diseases such as cancer and metastasis [1,2]. It has been shown, in both in vitro test and small animal model study, that polyphenols induce responses consistent with the protective effects of diets rich in fruits and vegetables against degenerative conditions such as cardiovascular disease and carcinogenesis [3,4]. Furthermore, they can be obtained without prescriptions. For example, fresh green tea contains large amounts of catechin polyphenol, while flavonoids resveratrol and quercetin are important in grapes, red wine, and other food products [5]. Epidemiologic studies suggest that diet can affect the risk for cancer and, particularly a diet rich in vegetables reduces this risk [6,7]. Apoptosis, or programmed cell death, is an important physiologic process in the normal development [8], and induction of apoptosis is a highly desirable mode as a therapeutic strategy for cancer control [9,10]. The major challenge in treating cancer is that many tumor cells carry mutations in key apoptotic genes such as p53, BCL family protein, or those affecting caspase signaling [11]. The BCL-2 family determines the life-or-death of a cell by controlling the release of mitochondrial apoptogenic factors associated with death proteases called caspases which are considered as a central player for the apoptotic process and cascade o
Reducibility of systems and existence of solutions for almost periodic differential equations
Jihed Ben Slimene,Joel Blot
Electronic Journal of Differential Equations , 2012,
Abstract: We establish the reducibility of linear systems of almost periodic differential equations into upper triangular systems of a. p. differential equations. This is done while the number of independent a. p. solutions is conserved. We prove existence and uniqueness of a. p. solutions of a nonlinear system with an a. p. linear part. Also we prove the continuous dependence of a. p. solutions of a nonlinear system with respect to an a. p. control term.
A bound for ratios of eigenvalues of Schrodinger operators with single-barrier potentials
Jamel Ben Amara,Hedhly Jihed
Mathematics , 2015,
Abstract: M. Horvath and M. Kiss $\left[\text{Proc. Amer. Math. Soc},\left(2005\right) \right],$ proved that the upper estimate $\frac{\lambda_{n}}{% \lambda_{m}}\leq \frac{n^{2}}{m^{2}}$ $\left(n>m\geq 1\right) $ of Dirichlet Shrodinger operators with nonnegative and single-well potentials. In this paper we discuss the case of nonpositive potentials $q(x)$ defined and continuous on the interval $\left[0,1\right] $. Namely, we prove that if $q(x)\leq 0$ \ and single-barrier$\ $then $\frac{\lambda_{n}}{\lambda_{m}}\geq \frac{n^{2}}{m^{2}}$ for $\lambda_{n}>\lambda_{m}\geq -2q_{\_},$ where $q_{\_}=\min \left\{q(x),\text{}x\in \left[0,1\right] \right\} $. Moreover we show that there exixst $l_{0}\in \left(0,1\right] $ such that if $\ q(x)\leq 0$ and single-barrier, then the associated eigenvalues $% \left(\lambda_{n}\left(\ell_{0}\right) \right)_{n\geq 1}$ satisfy $% \lambda_{1}\left(\ell_{0}\right) >0$ and $\frac{\lambda _{n}\left(\ell _{0}\right)}{\lambda_{m}\left(\ell_{0}\right)}\geq \frac{n^{2}}{m^{2}}$ for $n>m\geq 1$.
Preludes to the Lattice Compatibility Theory LCT: Urbach Tailing Controversial Behavior in Some Nanocompounds
K. Boubaker
ISRN Nanomaterials , 2012, DOI: 10.5402/2012/173198
A Confirmed Model to Polymer Core-Shell Structured Nanofibers Deposited via Coaxial Electrospinning
K. Boubaker
ISRN Polymer Science , 2012, DOI: 10.5402/2012/603108
Page 1 /102
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.