Ethyl acetate extract and its major constituent, isorhamnetin 3-O-rutinoside, from Nitraria retusa leaves, promote apoptosis of human myelogenous erythroleukaemia cells.

OBJECTIVE: Fractionation of ethyl acetate extract (EA) obtained from Nitraria retusa leaves was assessed using different methods of chromatography, and isorhamnetin3-O-rutinoside (I3-O-R) was isolated from this extract. Its structure was determined using data obtained from (1) H and (13) C NMR spectra, as well as by various correlation experiments (COSY, HMQC and HMBC). Both EA extract and I3-O-R were investigated for their ability to induce apoptosis in human chronic myelogenous erythroleukaemia cells (K562). MATERIALS AND METHODS: Apoptosis of cells from the K562 line was detected by DNA fragmentation, PARP cleavage and by evaluating activities of caspases 3 and 8. RESULTS: Apoptosis, revealed by DNA fragmentation and PARP cleavage, was observed after 48-h incubation of these human myelogenous erythroleukaemia cells (K562), with the tested products. Likewise, caspase 3 and caspase 8 activities were induced in the presence of the EA extract and I3-O-R after 48 h of incubation. CONCLUSION: Our results strongly suggest the involvement of the extrinsic pathway of apoptosis in cells treated by both the original EA extract and its major component, I3-O-R.

Antimutagenic, antigenotoxic and antioxidant activities of phenolic-enriched extracts from Teucrium ramosissimum: combination with their phytochemical composition.

The evaluation of the mutagenic and antimutagenic actions of extracts obtained from aerial part of Teucrium ramosissimum was assayed using the Salmonella typhimurium assay system. The effect of the same extracts on genotoxicity and SOS response induced by aflatoxin B(1) as well as nitrofurantoin was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The different extracts showed no mutagenicity when tested with Salmonella typhimurium strains TA100, TA98 and TA1535 either with or without S9 mix. In contrast, our results prove that T. ramosissimum extracts possess antimutagenic effects against sodium azide, aflatoxin B1, benzo[a]pyrene and 4-nitro-o-phenylenediamine. Moreover, the T. ramosissimum tested extracts exhibited no genotoxicity either with or without the external S9 activation mixtures. However, all the extracts significantly decreased the genotoxicity induced by aflatoxin B(1) and nitrofurantoin. The result obtained by the Ames test confirms those of SOS chromotest. Antioxidant capacity of the tested extracts was evaluated using the enzymatic (xanthine/xanthine oxidase assay) and the non enzymatic (NBT/riboflavine, DPPH and ABTS assays) systems. All extracts exhibited high antioxidant activity except the chloroform and the methanol extracts in DPPH and NBT/riboflavine assays respectively. Our results underline the potential of T. ramosissimum to avoid mutations and also its antioxidant potential.

Chemical investigation of different crude extracts from Teucrium ramosissimum leaves. Correlation with their antigenotoxic and antioxidant properties.

The effect of extracts obtained from Teucrium ramosissimum leaves on genotoxicity and SOS response induced by aflatoxin B(1) (0.5 µg/assay) as well as nitrofurantoin (5 µg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The T. ramosissimum tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly the total oligomers flavonoids (TOF) extract significantly decreased the genotoxicity induced by aflatoxin B(1) and nitrofurantoin. Antioxidant capacity of the tested extracts was evaluated using the enzymatic (xanthine/xanthine oxidase assay) (X/XOD) and the non-enzymatic (NBT/Riboflavine assay) systems. TOF extract was the most effective one in inhibiting both xanthine oxidase activity and NBT reduction. Our findings emphasize the potential of T. ramosissimum to prevent mutations and also its antioxidant effect.

Assessment of phenolic content, free-radical-scavenging capacity genotoxic and anti-genotoxic effect of aqueous extract prepared from Moricandia arvensis leaves.

The present study was undertaken to provide a set of data on the safety of an aqueous extract (AQE) from Moricandia arvensis. For this reason, Escherichia coli tested strains PQ35 and PQ37 were used to detect induction of DNA lesions by AQE. The SOS Chromotest showed that AQE induced a marginally genotoxic effect, as expressed by the induction factor (IF) value only with E. coli PQ37 tested strain (IF=1.77 at a dose of 250 microg/assay). The measurement of the anti-genotoxic activity of the AQE was also studied by inhibition of beta-galactosidase induction. A significant anti-genotoxic effect was observed with different tested doses of AQE, which suggests that M. arvensis extract has the potential to protect DNA from the action of nitrofurantoïn (NF) and free radicals generated by hydrogen peroxide (H2O2). In addition to anti-genotoxic activity, AQE showed a free-radical-scavenging capacity towards ABTS+* and DPPH*. Total phenolic content was also evaluated following Folin-Ciocalteu method and results indicated high correlation between total phenol content and anti-genotoxic and antioxidant activities for AQE, but the highest correlation was showed with its capacity to stabilize ABTS+* (R2=0.9944).

Antigenotoxic and antioxidant activities of Pituranthos chloranthus essential oils.

The SOS-chromotest in Escherichia coli is a widely used bacterial genotoxicity assay to test potential carcinogens. The aim of this work is to evaluate the genotoxic and antigenotoxic activities of essential oils obtained from aerial parts of Pituranthos chloranthus. The tested essential oils were not genotoxic towards both E. coli PQ37 and PQ35 strains. These essential oils reduced significantly Nifuroxazide and H(2)O(2)-induced genotoxicity. Essential oils showed a protective effect against damages induced by radicals, obtained from the photolysis of H(2)O(2), on DNA plasmid through free radical scavenging mechanisms. The scavenging capacity of these essential oils was also estimated by evaluating the inhibition of ABTS(+.) radical.