In vitro inhibition of food borne mutagens induced mutagenicity by cinnamon (Cinnamomum cassia) bark extract.

Cinnamon (Cinnamomum cassia) is an important spice which is widely consumed in the Indian subcontinent as well as in several other parts of the world. In the present study, NMR spectroscopy showed the presence of cinnamaldehyde to be the major component of the bark. The possible mutagenic effects of cinnamon bark ethanolic extract (CEE, 0.01-1 mg/plate) cinnamon oil (CNO, 0.125-1 mg/plate), and its active component cinnamadehyde (CLD, 0.125-1 mg/plate) were evaluated. Antimutagenic activity of CEE, CNO, and CLD was also tested against various food borne mutagens (heterocyclic amines and aflatoxin B1 (AFB1)) and sodium azide (SA) using Ames assay. Similarly, the antimicrobial activity was studied using agar well diffusion assay against various pathogens. CEE was non-mutagenic in any of the five tester strains of Salmonella typhimurium (TA97a, TA98, TA100, TA102, and TA104) in Ames test. CEE exhibited antimutagenic activity against all the mutagens tested in the higher doses. Additionally, CEE, CNO, and CLD were effective against various pathogens such as Staphylococcus aureus, Proteus vulgaris, S. typhimurium, Klebsiella pneumoniae, and Escherichia coli in the agar well diffusion assay. Promising antimutagenic and antimicrobial properties were shown by the cinnamon bark ethanolic extract and cinnamaldehyde, respectively. Therefore, their role in cancer chemoprevention, as well as a natural antimicrobial agent must be exploited and studied in depth in in vivo conditions.

Ameliorative effect of vitamin E and selenium against oxidative stress induced by sodium azide in liver, kidney, testis and heart of male mice.

The study purported to define the effects of daily administration of vitamin E (Vit E) and selenium (Se) on antioxidant enzyme activity in mice treated with high doses of sodium azide (SA). Male mice were randomly split into nine groups. Groups 1, 2 and 3 were injected daily with saline, Vit E, and Se, respectively, while groups 4, 5 and 6 administrated with different doses of SA (low, medium and high, respectively). The mice in groups 7, 8 and 9 received 100mg/kg Vit E, 17.5mg/kg Se, and a combination of Vit E and Se, respectively before the SA-treatment. Hepatic, renal, testis and heart, antioxidant enzymes as well as levels of lipid peroxidation and total antioxidant capacity levels were determined. Vit E alone affected on the antioxidant parameters of the examined tissues. Se had a preventive effect on the decrease of antioxidant parameters caused by SA and improved the diminished activities of all of them. The study demonstrates that a high dose of SA may alter the effects of normal level antioxidant/oxidative status of male mice and that Se is effective in reducing the SA-damage. Se acts as a synergistic agent with the effect of Vit E in various damaged caused by SA.

Phenotypic and biochemical profile changes in calendula (Calendula officinalis L.) plants treated with two chemical mutagenesis.

Chemical mutagenesis is an efficient tool used in mutation-breeding programs to improve the vital characters of the floricultural crops. This study aimed to estimate the effects of different concentrations of two chemical mutagens; sodium azide (SA) and diethyl sulfate (DES). The vegetative growth and flowering characteristics in two generations (M1 and M2) of calendula plants were investigated. Seeds were treated with five different concentrations of SA and DES (at the same rates) of 1000, 2000, 3000, 4000, and 5000 ppm, in addition to a control treatment of 0 ppm. Results showed that lower concentrations of SA mutagen had significant effects on seed germination percentage, plant height, leaf area, plant fresh weight, flowering date, inflorescence diameter, and gas-exchange measurements in plants of both generations. Calendula plants tended to flower earlier under low mutagen concentrations (1000 ppm), whereas higher concentrations delayed flowering significantly. Positive results on seed germination, plant height, number of branches, plant fresh weight, and leaf area were observed in the M2-generation at lower concentrations of SA (1000 ppm), as well as at 4000 ppm DES on number of leaves and inflorescences. The highest total soluble protein was detected at the concentrations of 1000 ppm SA and 2000 ppm DES. DES showed higher average of acid phosphatase activity than SA. Results indicated that lower concentrations of SA and DES mutagens had positive effects on seed germination percentage, plant height, leaf area, plant fresh weight, flowering date, inflorescence diameter, and gas-exchange measurements. Thus, lower mutagen concentrations could be recommended for better floral and physio-chemical performance.

Red light of the visual spectrum attenuates cell death in culture and retinal ganglion cell death in situ.

PURPOSE: To ascertain whether red light, known to enhance mitochondrial function, can blunt chemical insults to cell cultures and ischaemic insults to the rat retina. METHODS: Raised intraocular pressure (IOP, 140 mmHg, 60 min) or ischaemia was delivered in complete darkness or in the presence of low intensity red light (16.5 watts/m(2) , 3000 lux, 625-635 nm) to one eye of each rat. Animals were killed at specific times after ischemia and retinas analysis for ganglion cell numbers, the localization of specific antigens or for changes in defined RNAs. RGC-5 cell cultures were also exposed to various chemical insults in the presence or absence of red light. Significant differences were determined by t-test and anova. RESULTS: Elevation of IOP causes changes in the localization of glial fibrillary acid protein (GFAP), calretinin, calbindin, choline acetyltransferase, ganglion cell numbers and an elevation (GFAP, vimentin, HO-1 and mTORC1) or reduction (Thy-1 and Brn3a) of mRNAs in the rat retina. These negative effects to the rat retina caused by ischaemia are reduced by red light. Moreover, chemical insults to cell cultures are blunted by red light. CONCLUSIONS: Low, non-toxic levels of red light focussed on the retina for a short period of time are sufficient to attenuate an insult of raised IOP to the rat retina. Since mitochondrial dysfunctions are thought to play a major role in ganglion cell death in glaucoma, we propose the potential use of red light therapy for the treatment of the disease.

Kolaviron was protective against sodium azide (NaN3) induced oxidative stress in the prefrontal cortex.

Kolaviron is a phytochemical isolated from Garcina kola (G. kola); a common oral masticatory agent in Nigeria (West Africa). It is a bioflavonoid used--as an antiviral, anti-inflammatory and antioxidant--in relieving the symptoms of several diseases and infections. In this study we have evaluated the neuroprotective and regenerative effect of kolaviron in neurons of the prefrontal cortex (Pfc) before or after exposure to sodium azide (NaN3) induced oxidative stress. Separate groups of animals were treated as follows; kolaviron (200 mg/Kg) for 21 days; kolaviron (200 mg/Kg for 21 days) followed by NaN3 treatment (20 mg/Kg for 5 days); NaN3 treatment (20 mg/Kg for 5 days) followed by kolaviron (200 mg/Kg for 21 days); 1 ml of corn-oil (21 days-vehicle); NaN3 treatment (20 mg/Kg for 5 days). Exploratory activity associated with Pfc function was assessed in the open field test (OFT) following which the microscopic anatomy of the prefrontal cortex was examined in histology (Haematoxylin and Eosin) and antigen retrieval Immunohistochemistry to show astroglia activation (GFAP), neuronal metabolism (NSE), cytoskeleton (NF) and cell cycle dysregulation (p53). Subsequently, we quantified the level of Glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the brain tissue homogenate as a measure of stress-related glucose metabolism. Kolaviron (Kv) and Kolaviron/NaN3 treatment caused no prominent change in astroglia density and size while NaN3 and NaN3/Kv induced astroglia activation and scar formation (astrogliosis) in the Pfc when compared with the control. Similarly, Kolaviron and Kv/NaN3 did not alter NSE expression (glucose metabolism) while NaN3 and NaN3/Kv treatment increased cortical NSE expression; thus indicating stress related metabolism. Further studies on enzymes of glucose metabolism (G6PDH and LDH) showed that NaN3 increased LDH while kolaviron reduced LDH in the brain tissue homogenate (P < 0.001). In addition kolaviron treatment before (P < 0.001) or after (P < 0.05) NaN3 treatment also reduced LDH expression; thus supporting its role in suppression of oxidative stress. Interestingly, NF deposition increased in the Pfc after kolaviron treatment while Kv/NaN3 showed no significant change in NF when compared with the control. In furtherance, NaN3 and NaN3/Kv caused a decrease in NF deposition (degeneration). Ultimately, the protective effect of KV administered prior to NaN3 treatment was confirmed through p53 expression; which was similar to the control. However, NaN3 and NaN3/Kv caused an increase in p53 expression in the Pfc neurons (cell cycle dysregulation). We conclude that kolaviron is not neurotoxic when used at 200 mg/Kg BW. Furthermore, 200 mg/Kg of kolaviron administered prior to NaN3 treatment (Kv/NaN3) was neuroprotective when compared with Kolaviron administered after NaN3 treatment (NaN3/Kv). Some of the observed effects of kolaviron administered before NaN3 treatment includes reduction of astroglia activation, absence of astroglia scars, antioxidation (reduced NSE and LDH), prevention of neurofilament loss and cell cycle regulation.

Effect of vitamin E and selenium separately and in combination on biochemical, immunological and histological changes induced by sodium azide in male mice.

Sodium azide (SA) is used as an active ingredient to control a broad spectrum of soil borne pathogens including insects, weeds, nematodes, fungi, and bacteria. The purpose of this study was to evaluate the ameliorator property of vitamin E (Vit E) or/and selenium (Se) against SA-induced injury in male mice at the biochemical, immunological and histological levels. The mice were divided into nine groups (10/group). The first three groups were served as control, Vit E and Se while, the second three groups were treated with three different doses of SA. The last three groups were treated with high dose of SA with Vit E or Se or Vit E and Se and all animals were treated for a period of 30 days. Exposure to SA at the three doses to mice led to an alternation of liver and kidney functions, decrease the testosterone concentration, decreased IgG and IgM levels as well as the increasing the TNF-α. The effects of SA on the biochemical parameters of mice were dose-dependent. Administration of Se or/and Vit E to SA-treated mice attenuates the toxicity of this compound, objectified by biochemical and histological improvement of liver, kidney and testis. But, the alleviation is more pronounced with the both antioxidants. Thus, the synergistic effect of Se and Vit E is most powerful in reducing the toxicity induced by SA and improving the humoral immune response of mice.

Antioxidant and antigenotoxic activities in Acacia salicina extracts and its protective role against DNA strand scission induced by hydroxyl radical.

The antioxidant potency of Acacia salicina extracts was investigated. Total antioxidant capacity was determined using an ABTS(+) assay. Superoxide radical scavenging was measured using riboflavin-light-nitro blue tetrazolium (NBT) assay. In addition, the content of phenols, total flavonoids and sterols were measured in the tested extracts. The petroleum ether exhibited a potent scavenging activity toward ABTS radical cations. Whereas, chloroform extract showed the highest activity against superoxides radicals and was also able to protect pKS plasmid DNA against hydroxyl radicals induced DNA damages. The antimutagenicity of these extracts was assayed using the Ames assay against Salmonella typhimurium TA98 and S. typhimurium TA 1535 tester strains at different concentrations. These extracts decreased significantly the mutagenecity induced by sodium azide (SA) and 4-nitro-o-phenylenediamine (NOP). The antioxidant and antimutagenecity activities exhibited by A. salicina depended on the chemical composition of the tested extracts.

Protective effects of methanol extracts from Cladonia rangiformis and Umbilicaria vellea against known mutagens sodium azide and 9-aminoacridine.

Lichens and their various extracts have been occasionally used in the treatment of many diseases. Cladonia rangiformis and Umbilicaria vellea are two important species of these lichens and they have several biological activities. In the present study, methanol extracts of these lichens, which are grown in the Eastern Anatolia Region of Turkey, were isolated, and their mutagenic and antimutagenic properties were investigated by using AMES-Salmonella and Zea mays Root Tip Mitotic Index mutagenicity and antimutagenicity assay systems. Known mutagens sodium azide (NaN(3)) and 9-Aminoacridine (9-AA) were used to determine antimutagenic properties of methanol extracts. The results showed that all methanol extracts, investigated in the present study, can be considered genotoxically safe because they do not have mutagenic activity at the tested concentrations. Besides, all of them have antimutagenic activity against 9-AA known as a model intercalator agent in the AMES-Salmonella test system. The inhibition rates obtained from the antimutagenicity assays ranged from 37.07% (C. rangiformis-5 µg/plate) to 54.39% (C. rangiformis-5 µg/plate). Furthermore, all the methanol extracts have significant antimutagenic activity against NaN(3) mutagenicity in Z. mays Root Tip Mitotic Index assay system. These activities are valuable towards an extension of the employ of these drugs as new phytotherapeutic or preservative ingredients.

A competition-based assay for the screening of species-specific antibiotics.

OBJECTIVES: To develop a high throughput screening-compatible assay for the selection of species-specific antibiotics that do not harm human cells. METHODS: Staphylococcus aureus and human reporter cells continuously generating a fluorescence signal were competitively co-cultivated. The fluorescence signals were determined in the presence and absence of the specific antibiotic streptomycin and the toxic compound sodium azide. The results were compared with a standard cfu assay. RESULTS: In the absence of an effective antibiotic, S. aureus outgrew the human reporter cells and thus abolished the fluorescence signal. Conversely, the addition of streptomycin resulted in the growth of the reporter cells and a strong fluorescence signal. When sodium azide was added instead of streptomycin, only a very low background signal was obtained indicating toxicity and damage to the human reporter cells. The assay proved to be highly reliable (Z-factor >0.9) and high fluorescence signals correctly correlated with the efficient inhibition of S. aureus, as determined in comparative cfu assays. CONCLUSIONS: In contrast to conventional cfu assays, the co-cultivation system allows the effects of a drug candidate on pathogens and human cells to be monitored simultaneously. Cytotoxic compounds can, therefore, be quickly ruled out during a primary screen. The nature of the screen also enables effective antibiotics to be identified without engineering the target pathogen to yield a fluorescence signal.

Moricandia arvensis extracts protect against DNA damage, mutagenesis in bacteria system and scavenge the superoxide anion.

The mutagenic potential of total aqueous, total oligomers flavonoids (TOF), ethyl acetate (EA), chloroform (Chl), petroleum ether (PE) and methanol (MeOH) extracts from aerial parts of Moricandia arvensis was assessed using Ames Salmonella tester strains TA100 and TA1535 with and without metabolic activation (S9), and using plasmid pBluescript DNA assay. None of the different extracts produced a mutagenic effect, except aqueous extract when incubated with Salmonella typhimurium TA100 after metabolic activation. Likewise, the antimutagenicity of the same extracts was tested using the "Ames test". Our results showed that M. arvensis extracts possess antimutagenic effects against sodium azide (SA) in the two tested Salmonella assay systems, except metabolized aqueous and PE extracts when tested with S. typhimurium TA100 assay system. Different extracts were also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals, except PE and aqueous extracts. 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 more effective one in inhibiting both xanthine oxidase activity and NBT reduction.

Maternal and developmental toxicity study of sodium azide in rats.

Sodium azide (NaN(3)) is being proposed for use as an active ingredient to control a broad spectrum of soil borne pathogens including insects, weeds, nematodes, fungi, and bacteria. The purpose of this study was to determine the maternal and developmental toxicity of NaN(3) in rats. Sperm-positive Sprague-Dawley rats were treated with NaN(3) via oral gavage once daily from Gestation Day (GD) 6 through 19 at respective dose levels of 0, 1, 5, and 17.5mg/kg/day. From GD 10-12, the high-dose was reduced to 10mg/kg/day due to maternal mortality. Cesarean section was performed on GD 20 and implantation and resorptions sites, live and dead fetuses were counted. Fetuses were weighed, sexed externally and processed for gross external, visceral and skeletal examinations. A high rate of maternal mortality; reduced gestation body weight, gestation body weight changes and food consumption; decreased corrected body weight and corrected weight gain were observed at 17.5/10mg/kg/day. Fetal weight was also reduced at 17.5/10mg/kg/day. There were no maternal deaths, clinical signs or body weight effects that were considered related to NaN(3) at 1 and 5mg/kg/day. No increase in the incidence of malformations and variations were observed at any of the doses evaluated. Based on the results of this study, the No Observed Adverse Effect Level (NOAEL) and the Lowest Observed Adverse Effect Level (LOAEL) for maternal and developmental toxicity of NaN(3) in rats were considered to be 5 and 17.5/10mg/kg/day, respectively.

Antioxidant activity and inhibition of aflatoxin B1-, nifuroxazide-, and sodium azide-induced mutagenicity by extracts from Rhamnus alaternus L.

The effect of extracts obtained from Rhamnus alaternus L. leaves on genotoxicity and SOS response induced by aflatoxin B(1) (10 microg/assay) as well as nifuroxazide (20 microg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The evaluation of the mutagenic and antimutagenic actions of the same extracts against the sodium azide (1.5 microg/plate)-induced mutagenicity was assayed using the Salmonella typhimurium assay system. The R. alaternus tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly aqueous extract (A) and its chloroformic fraction (A(2)) significantly decreased the genotoxicity induced by aflatoxin B(1) and nifuroxazide. Moreover, the different extracts showed no mutagenicity when tested with Salmonella typhimurium strains TA1535 and TA1538 either with or without the S9 mix. Aqueous extract as well as its A(2) fraction exhibited the highest level of protection towards the direct mutagen, sodium azide-induced response in TA1535 strain with mutagenicity inhibition percentages of 83.6% and 91.4%, respectively, at a dose of 250 microg/plate. The results obtained by the Ames test assay confirm those of SOS chromotest. These same active extracts exhibited high xanthine oxidase (XOD) inhibiting with respective IC(50) values of 208 and 137 microg/ml, and superoxide anion-scavenging effects (IC(50) values of 132 and 117 microg/ml) when tested in the XOD enzymatic assay system. Our findings emphasize the potential of R. alaternus to prevent mutations and also its antioxidant effect.

Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa.

Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 microg/ml for 3 h and curcumin was given at 5, 10 and 20 microg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 microg/ml in Allium cepa root meristem cells.

The study of antioxidant and anticarcinogenic green tea and black tea.

Tea is one of the most popular beverages consumed worldwide. The relationship between tea consumption and human cancer incidence is an important concern. The effect of tea extract and ingredients, polyphenol and caffeine on the mutagenicity of Sodium Azide was examined in vitro by using Salmonella typhimurium TA100, TA98 and TA1535 in the presence of induced rat liver S9 fractions. Experimental studies have demonstrated the significant antimutagenic and anticarcinogenic effects of both Green and Black tea and its polyphenol and caffeine multiple mutational assay. Caffeine was the less active. Tea comes in many variants. Common tea such as Black tea contains little antioxidant and the amount of caffeine. Green tea has about the caffeine, but contains a good amount of antioxidant.

Modulatory effect of phenolic fractions of Terminalia arjuna on the mutagenicity in Ames assay.

We determined the antimutagenicity of phenolic fractions of Terminalia arjuna (soluble and insoluble in chloroform) against two direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and sodium azide, and against the S9-dependent mutagen 2-aminofluorene (2AF), in TA98 and TA100 tester strains of Salmonella typhimurium. We found that the phenolic fractions of T. arjuna inhibited revertants induced by the S9-dependent mutagen more remarkably than the direct-acting mutagens. Furthermore, the phenolic fractions showed maximum inhibition of 98% and 101.55%, respectively, in the pre-incubation mode of treatment against the mutations induced by 2AF. Overall, the fractions inhibited the revertants induced by S9-dependent mutagens more effectively than those induced by direct-acting mutagens. The percentage of inhibition was higher in the pre-incubation than with direct acting mutagens. The fraction insoluble in chloroform showed more inhibition than the soluble one, which corresponds to a higher polyphenol content in the insoluble fraction than in the soluble extract.

A correlative study on antimutagenic and chemopreventive activity of Acacia auriculiformis A. Cunn. and Acacia nilotica (L.) Willd. Ex Del.

The present study provides a correlation of the antimutagenic and chemopreventive activity of the barks of two commonly observed plants viz. Acacia auriculiformis and Acacia nilotica. We used the Ames antimutagenicity assay and the mouse mammary gland organ culture (MMOC) model. The plants were extracted with organic solvents to obtain chloroform fractions and acetone extracts. The antimutagenic activity was determined in two different strains using both direct-acting [4-nitro-o-phenylenediamine (NPD) or sodium azide] and indirect-acting [2-aminofluorene (2AF)] mutagens. The anticarcinogenic activity was evaluated based on the development of preneoplastic lesions in response to the chemical carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). The results showed that the activity resulting from the 2AF mutagen was selectively greater than the activity from the direct-acting mutagens. Moreover, in general, acetone extracts were more potent in suppressing mutagenesis than the chloroform extracts. The antimutagenicity results obtained with extracts using the 2AF--TA100 system were comparable to the chemopreventive results with DMBA-induced mammary lesions. The order of activity in both tests was A. nilotica > A. auriculiformis. These results exhibited a good correlation between the antimutagenesis assay and the MMOC model, suggesting that these plants may contain active chemopreventive agents.

Modulatory effects of a tannin fraction isolated from Terminalia arjuna on the genotoxicity of mutagens in Salmonella typhimurium.

A fraction isolated from Terminalia arjuna was studied for its antimutagenic effect against 4-nitro-o-phenylenediamine (NPD) in TA98, sodium azide in TA100 and 2-aminofluorene (2AF, S9-dependent), a promutagen, in both TA98 and TA 100 tester strains of Salmonella typhimurium using the Ames assay. The fraction inhibited the mutagenicity of 2AF very significantly in both strains while the revertant colonies induced by NPD and sodium azide were reduced moderately. 1H-NMR, 13C-NMR, IR and UV-spectroscopic data of the fraction revealed it to be tannin in nature.