Assessment in vitro of the genotoxicity, antigenotoxicity and antioxidant of Ceratonia siliqua L. extracts in murine leukaemia cells L1210 by comet assay.

Genotoxicity of Ceratonia siliqua extracts, was investigated by assessing their capacity to induce nucleus DNA degradation of murine leukaemia cells L1210, using the "Comet assay". The ability of total oligomer flavonoids (TOF) and aqueous extracts to protect cell DNA against oxidative stress induced by H2O2, was performed by pre- co or post-treatment of cells with the before mentioned extracts for different periods preceding exposure to H2O2 stress. No significant genotoxic effect was detected at different exposure times, except at the lowest concentration of TOF extract (16.25 µg/ml). It appears that extracts decreased DNA damage, induced by H2O2. Both of TOF and aqueous extracts exhibited cellular antioxidant capacity, with EC50 values of respectively <16.25 and < 35 µg/ml, as well as, a protective capacity against lipidperoxidation inducing using L1210 cells line as a cellular model. MDA inhibition percentages reached 88.43% and 90.52% with respectively 35.5 µg/ml of TOF extract and 70 µg/ml of aqueous extract. Antioxidant properties of carob leaf extracts revealed by our study make a good antioxidant protection and thus a good candidate as food addition component.

Genoprotective and neuroprotective effects of Daphne gnidium leaf methanol extract, tested on male mice.

Methanol extract of Daphne gnidium leaves was assessed for its antigenotoxic and neuroprotective effects through antioxidant and antibutyrylcholinesterase activities. Antigenotoxic activity was evaluated against methyl methanesulfonate injected intraperitoneally to mice, using the comet assay. The protective effect of D. gnidium reached 99.12%, at the lowest tested dose (44 mg/kg b.w.) in kidney cells, and 92.16% at the dose of 88 mg/kg b.w. in blood cells. The extract was dissolved in water and administrated to mice by intraperitoneal injection. Antioxidant activity was tested against DPPH radicals. It reached a maximum of 74.52% with an IC50 value of 45 µg/ml. Anticholinesterase activity was determined against butyrylcholinesterase, an enzyme linked to Alzheimer disease. The extract exhibited antibutyrylcholinestrase effect with an inhibition percentage of 35.82% at the lowest tested dose (44 mg/kg b.w.).

In vitro and in vivo anti-melanoma effects of Daphne gnidium aqueous extract via activation of the immune system.

The purpose of this study was to assess the antitumor and immunomodulatory effects of the aqueous extract from Daphne gnidium in mice-bearing melanoma tumor. Balb/C mice were subcutaneously implanted with B16-F10 cells and treated intraperitoneally with the aqueous extract at 200 mg/Kg b.w for 21 days. After euthanization on day 22, the tumors were weighed; lymphocyte proliferation, cytotoxic T lymphocyte (CTL), and natural killer (NK) cell activities were evaluated using the MTT assay. Macrophage phagocytosis was studied by measuring the lysosomal activity. In addition to its potential to inhibit the growth of the transplantable tumor, the aqueous extract remarkably induced splenocyte proliferation and both NK and CTL activities in tumor-bearing mice. The aqueous extract was also seen to have promoted lysosomal activity of host macrophages.

In vitro antileukaemic activity of extracts from Daphne gnidium leaves against sensitive and multidrug resistant K562/R7 cells.

The antiproliferative potential of extracts of Daphne gnidium L. (Thymelaeaceae) on K562 cells was assessed, and the capacity of these extracts to disturb the cell cycle of K562 cells and to inhibit human P-glycoprotein was evaluated. The antiproliferative activity was evaluated using the MTT assay. The cell cycle analysis and the inhibition of P-glycoprotein were tested by flow cytometry. All the tested extracts exhibited significant anti-proliferative effects. Ethyl acetate extract has the strongest cytotoxic effect with an IC50 of 18.5 µg/ml. Furthermore, cell cycle analysis revealed that cells treated with chloroform, butanol and aqueous extracts were arrested predominantly in G2-M phase. Butanol extract was the most active extract. Percentage of cells arrested in G2-M was 34 %, 36.67 % and 42.63 % respectively, after treatment with 25, 75 and 100 µg/ml of the extract, versus 19 % in the cells treated with the vehicle solvent. In addition, chloroform extract had the ability to inhibit human P-glycoprotein-mediated daunorubicin in K562/R7 leukaemic cells in a dose-dependent manner compared to the positive control, cyclosporin A. These findings demonstrate that extracts from D. gnidium leaves have antileukaemic activity by perturbing the cell cycle of K562 and inhibiting human P-glycoprotein in K562/R7 cell line.

Aqueous extract of Crataegus azarolus protects against DNA damage in human lymphoblast Cell K562 and enhances antioxidant activity.

The present study was carried out to characterize the cellular antioxidant effect of the aqueous extract of Crataegus azarolus and its antigenotoxic potential using human myelogenous cells, K562. The antioxidant capacity of this extract was evaluated by determining its cellular antioxidant activity (CAA) in K562 cells. Also, preceding antigenotoxicity assessment, its eventual genotoxicity property was investigated by evaluating its capacity to induce the DNA degradation of treated cell nuclei. As no genotoxicity was detected at different exposure times, its ability to protect cell DNA against H2O2 oxidative effect was investigated, using the "comet assay." It appears that 800 µg/mL of extract inhibited the genotoxicity induced by H2O2 with a rate of 41.30 %, after 4 h of incubation. In addition, this extract revealed a significant cellular antioxidant capacity against the reactive oxygen species in K562 cells.

Phytochemical potential of Daphne gnidium in inhibiting growth of melanoma cells and enhancing melanogenesis of B16-F0 melanoma.

In this study, we have investigated inhibitory capacity of ethyl acetate, total oligomer flavonoid (TOF), aqueous extracts and beta amyrin acetate, a triterpene isolated from ethyl acetate extract obtained from leaves of Daphne gnidium, on mouse melanoma (B16-F0 and B16-F10 cells) proliferation. Influence of these products on percentage cell distribution in cycle phases and melanogenesis was also studied. Cell viability was determined using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and flow cytometry was used to analyse effects of tested compounds on progression through the cell cycle. In addition, amounts of melanin and tyrosinase were measured spectrophotometrically at 475 nm. Ethyl acetate, TOF and aqueous extracts exhibited significant anti-proliferative activity after incubation with the two types of tumour skin cells B16-F0 and B16-F10. Furthermore, cell cycle analysis revealed that cells treated with ethyl acetate and TOF extracts were arrested predominantly in G2-M phase. Ethyl acetate extract has also the ability to enhance melanogenesis and tyrosinase activity of B16-F0 melanoma cells.

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.

Inhibition of proinflammatory macrophage responses and lymphocyte proliferation in vitro by ethyl acetate leaf extract from Daphne gnidium.

Medicinal plants are considered immunomodulatory as they display various biological activities. There is no report addressing the anti-inflammatory effects of Daphne gnidium. In this study, we investigated the effects of D. gnidium ethyl acetate (EA) leaf extract on mice immune cell function in vitro. Production of pro-inflammatory cytokines (IL-1ß and TNF-α), cyclooxygenase-2-derived prostaglandinE2 (PGE2) and iNOS-II-synthesised nitric oxide (NO) were examined. EA extract effect on mitogen-induced lymphocyte proliferation was also investigated. We reported for the first time that D. gnidium EA leaf extract dose-dependently inhibits macrophage proinflammatory function by reducing LPS-induced production of IL-1ß, TNF-α, COX-2-derived PGE2 and iNOS-II-synthesised NO. Mitogen-induced lymphocyte proliferation was also dose-dependently inhibited by the extract. Lectin-induced response appears to be more sensitive to the suppressive effects of the extract than LPS-stimulated response. Collectively, these results demonstrate that D. gnidium EA leaf extract acts as an in vitro anti-inflammatory factor by inhibiting mice macrophage and lymphocyte activities.