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1.  Limoniastrum guyonianum aqueous gall extract induces apoptosis in human cervical cancer cells involving p16INK4A re-expression related to UHRF1 and DNMT1 down-regulation 
Several reports have described the potential effects of natural compounds as anti-cancer agents in vitro as well as in vivo. The aim of this study was to evaluate the anti-cancer effect of Limoniastrum guyonianum aqueous gall extract (G extract) and luteolin in the human cervical cancer HeLa cell line, and, if so, to clarify the underlying mechanism. Our results show that G extract and luteolin inhibited cell proliferation and induced G2/M cell cycle arrest in a concentration and time-dependent manner. Both natural products induced programmed cell death as confirmed by the presence of hypodiploid G0/G1 cells. These effects are associated with an up-regulation of the expression of the tumor suppressor gene p16INK4A and a down-regulation of the expression of the anti-apoptotic actor UHRF1 and its main partner DNMT1. Moreover, G extract- and luteolin-induced UHRF1 and DNMT1 down-regulation is accompanied with a global DNA hypomethylation in HeLa cell line. Altogether our results show that G extract mediates its growth inhibitory effects on human cervical cancer HeLa cell line likely via the activation of a p16INK4A -dependent cell cycle checkpoint signalling pathway orchestrated by UHRF1 and DNMT1 down-regulation.
doi:10.1186/1756-9966-32-30
PMCID: PMC3695779  PMID: 23688286
Apoptosis; Epigenetic modifications; Gall extract; Tumor suppressor genes; UHRF1
2.  Antioxidant, genotoxic and antigenotoxic activities of daphne gnidium leaf extracts 
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.
doi:10.1186/1472-6882-12-153
PMCID: PMC3462690  PMID: 22974481
Daphne gnidium; Antioxidant; Antigenotoxic
3.  Isorhamnetin 3-O-robinobioside from Nitraria retusa leaves enhance antioxidant and antigenotoxic activity in human chronic myelogenous leukemia cell line K562 
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.
doi:10.1186/1472-6882-12-135
PMCID: PMC3439276  PMID: 22913434
4.  Investigation of the apoptotic way induced by digallic acid in human lymphoblastoid TK6 cells 
Background
The digallic acid (DGA) purified from Pistacia lentiscus. L fruits was investigated for its antiproliferative and apoptotic activities on human lymphoblastoid TK6 cells.
Methods
We attempt to characterize the apoptotic pathway activated by DGA. Apoptosis was detected by DNA fragmentation, PARP cleavage and by evaluating caspase activities.
Results
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.
Conclusion
In summary, DGA exhibited an apoptosis inductor effect in TK6 cells revealing thus its potential as a cancer-preventive agent.
doi:10.1186/1475-2867-12-26
PMCID: PMC3487787  PMID: 22686580
Caspase activity; DNA fragmentation; Digallic acid; PARP
5.  Polar extracts from (Tunisian) Acacia salicina Lindl. Study of the antimicrobial and antigenotoxic activities 
Background
Methanolic, aqueous and Total Oligomer Flavonoids (TOF)-enriched extracts obtained from the leaves of Acacia salicina 'Lindl.' were investigated for antibacterial, antimutagenic and antioxidant activities.
Methods
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.
Results
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.
Conclusions
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.
doi:10.1186/1472-6882-12-37
PMCID: PMC3353866  PMID: 22490278
Acacia salicina; Antigenotoxic activity; Antioxidant activities; Ames assay
6.  Antimutagenic and free radical scavenger effects of leaf extracts from Accacia salicina 
Background
Three extracts were prepared from the leaves of Accacia salicina; ethyl acetate (EA), chloroform (Chl) and petroleum ether (PE) extracts and was designed to examine antimutagenic, antioxidant potenty and oxidative DNA damage protecting activity.
Methods
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.
Results
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.+.
Conclusion
The present study revealed the antimutagenic and antioxidant potenty of plant extract from Accacia salicina leaves.
doi:10.1186/1476-0711-10-37
PMCID: PMC3267653  PMID: 22132863
7.  Leaf extracts from Nitraria retusa promote cell population growth of human cancer cells by inducing apoptosis 
Background
In this report the phytochemical profile of Nitraria. Retusa (N. Retusa) leaf extracts were identified and their ability to induce apoptosis in human chronic myelogenous erythroleukaemia (K562) was evaluated.
Methods
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.
Results
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.
Conclusion
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.
doi:10.1186/1475-2867-11-37
PMCID: PMC3224376  PMID: 22040460
9.  Comparative analysis of medicinal plants used in traditional medicine in Italy and Tunisia 
Background
Italy and Tunisia (Africa for the Romans), facing each other on the opposite sides of the Mediterranean Sea, have been historically linked since the ancient times. Over the centuries both countries were mutually dominated so the vestiges and traces of a mutual influence are still present. The aim of the present study is to conduct a comparative analysis of the medicinal species present in the respective Floras in order to explore potential analogies and differences in popular phytotherapy that have come out from those reciprocal exchanges having taken place over the centuries
Methods
The comparative analysis based on the respective floras of both countries takes into consideration the bulk of medicinal species mutually present in Italy and Tunisia, but it focuses on the species growing in areas which are similar in climate. The medicinal uses of these species are considered in accordance with the ethnobotanical literature.
Results
A list of 153 medicinal species belonging to 60 families, present in both floras and used in traditional medicine, was drawn. A considerable convergence in therapeutic uses of many species emerged from these data.
Conclusion
This comparative analysis strengthens the firm belief that ethno-botanical findings represent not only an important shared heritage, developed over the centuries, but also a considerable mass of data that should be exploited in order to provide new and useful knowledge.
doi:10.1186/1746-4269-5-31
PMCID: PMC2773757  PMID: 19857257

Results 1-9 (9)