Protective effects of Bidens pilosa on hepatoxicity and nephrotoxicity induced by carbon tetrachloride in rats.

The aim of this study was to assess the protective effects of oral and topical treatment with Bidens pilosa (BP) against carbon tetrachloride (CCl4)- induced toxicity. Fifty-six rats were divided into seven groups: A: CCl4 only; B: CCl4+oral BP; C: CCl4 and topical BP; D: CCl4+oral and topical BP; E: oral BP only; F: negative control; and G: positive control (cyclophosphamide). The animals were treated for 10 weeks. Blood samples were collected for tests of hepatic and renal function, and fragments of the liver, spleen, pancreas, kidney, and intestine were collected for histopathological analyses. Cells from the femoral bone marrow were used for a micronucleus test and 'comet assay'. Statistically significant differences were observed in the levels of gamma-glutamyl transpeptidase (GGT), albumin, urea and creatinine, hepatic inflammation, renal tubular lesion, and inflammation of the intestinal mucosa between the BP-treated groups and untreated group. The median number of micronuclei in group A was 4.00, in group G was 9.00 and in the other groups was 0.00. Group A had the lowest number of cells with a score of 0 and the greatest number with scores of 3 and 4, similar to the results obtained from group G using the 'comet assay'. Thus, BP effectively protected against the toxic effects of CCl4 on the liver, kidney, and intestine and exerted an antimutagenic effect on rats exposed to CCl4.

Low-polar extract from seed of Cleistocalyx nervosum var. paniala modulates initiation and promotion stages of chemically-induced carcinogenesis in rats.

BACKGROUND: Cleistocalyx nervosum var. paniala is a local fruit mainly cultivated in the north of Thailand. Our previous study has reported that the methanol extract of C. nervosum seed presented antimutagenicity in a Salmonella mutation assay. The present study focused on the effect of a low-polar extract of C. nervosum seed on the early stages of diethylnitrosamine (DEN)- and dimethylhydrazine (DMH)-induced carcinogenesis in rats. METHODS: Dried C. nervosum seed powder was extracted using dichloromethane. To study its effect on the initiation stage of carcinogenesis of rats, they were fed with various doses of C. nervosum seed extract (CSE) for 21 days. DEN injection was used to initiate hepatocarcinogenesis and partial hepatectomy was performed to amplify mutated hepatocytes resulting in micronucleated hepatocyte formation. To study the role of CSE on the promotion stage, rats were injected with DEN and DMH to induce preneoplastic lesions and the numbers of glutathione S-transferase placental form (GST-P) positive foci in the liver and aberrant crypt foci (ACF) in the colon were measured. This was followed by CSE administration for 10 weeks. The inhibitory mechanisms of CSE on initiation and promotion stages, including xenobiotic metabolism, cell proliferation and apoptosis, were investigated. RESULTS: The total phenolic content in CSE was 80.34 ± 2.29 mg gallic acid equivalents (GAE) per g of extract and 2,4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone was found to be a major flavonoid. The main terpenoids in CSE were ß-selinene, α-selinene, γ-selinene and o-cymene while 24(Z)-methyl-25-homocholesterol was a major phytosterol. CSE significantly decreased the number of micronucleated hepatocytes in DEN-initiated rats and enhanced the activities of hepatic glutathione S-transferase and UDP-glucuronyltransferase. Furthermore, the formation of preneoplastic lesions in the liver and colon was statistically reduced by CSE. CSE also diminished cell proliferation in the liver and colon indicated by the number of PCNA positive cells. However, CSE did not alter the numbers of apoptotic hepatocytes and colonocytes in DEN- and DMH-initiated rats. CONCLUSIONS: The dichloromethane extract of C. nervosum seed demonstrated chemopreventive effects on chemically-induced carcinogenesis in both initiation and promotion stages in rats. The inhibitory mechanism might be involved in the modulation of hepatic detoxifying enzymes and suppression of hepatocyte and colonocyte proliferation.

Genotoxicity studies with an ethanolic extract of Kalanchoe pinnata leaves.

Kalanchoe pinnata is a medicinal plant, used mainly in African, Brazilian, and Indian traditional medicine for the treatment of several human disorders. Whole leaf extracts, crude juice of the leaves, and aqueous and organic extracts of the leaves are used. Over the last decade, ethanolic extracts have become the most popular form of Kalanchoe medicinal preparation. In this study, an ethanolic extract of this plant leaf was tested in a battery of standard regulatory genetic toxicology tests. This extract did not induce reverse mutations in the Salmonella/microsome assay but induces a weak genotoxic response in the mouse lymphoma assay and the in vivo micronucleus assay in mice. Our results indicate that this material may cause DNA damage, and its use should be restricted.

Inhibitory effect of purple rice husk extract on AFB1-induced micronucleus formation in rat liver through modulation of xenobiotic metabolizing enzymes.

BACKGROUND: Rice husk, a waste material produced during milling, contains numerous phytochemicals that may be sources of cancer chemopreventive agents. Various biological activities of white and colored rice husk have been reported. However, there are few comparative studies of the cancer chemopreventive effects of white and colored rice husk. METHODS: This study investigated the cancer chemopreventive activities of two different colors of rice husk using in vitro and in vivo models. A bacterial mutation assay using Salmonella typhimurium strains TA98 and TA100 was performed; enzyme induction activity in murine hepatoma cells was measured, and a liver micronucleus test was performed in male Wistar rats. RESULTS: The white rice husk (WRHE) and purple rice husk (PRHE) extracts were not mutagenic in Salmonella typhimurium TA98 or TA100 in the presence or absence of metabolic activation. However, the extracts exhibited antimutagenicity against aflatoxin B1 (AFB1) and 2-amino-3,4 dimethylimidazo[4,5-f]quinolone (MeIQ) in a Salmonella mutation assay. The extracts also induced anticarcinogenic enzyme activity in a murine Hepa1c1c7 hepatoma cell line. Interestingly, PRHE but not WRHE exhibited antigenotoxicity in the rat liver micronucleus test. PRHE significantly decreased the number of micronucleated hepatocytes in AFB1-initiated rats. PRHE contained higher amounts of phenolic compounds and vitamin E than WRHE in both tocopherols and tocotrienols as well as polyphenol such as cyanidin-3-glucoside, protocatechuic acid and vanillic acid. Furthermore, PRHE increased CYP1A1 and 1A2 activities while decreasing CYP3A2 activity in the livers of AFB1-treated rats. PRHE also enhanced various detoxifying enzyme activities, including glutathione S-transferase, NAD(P)H quinone oxidoreductase and heme oxygenase. CONCLUSIONS: PRHE showed potent cancer chemopreventive activity in a rat liver micronucleus assay through modulation of phase I and II xenobiotic metabolizing enzymes involved in AFB1 metabolism. Vitamin E and phenolic compounds may be candidate antimutagens in purple rice husk.

Aloe vera modulates X-ray induced hematological and splenic tissue damage in mice.

The present study was premeditated to examine the radioprotective effects of aqueous Aloe vera gel extract against whole-body X-ray irradiation-induced hematological alterations and splenic tissue injury in mice. Healthy male balb/c mice were divided into four groups: group 1, control; group 2, A. vera (50 mg/kg body weight) administered per oral on alternate days for 30 days (15 times); group 3, X-ray exposure of 2 Gy (0.25 Gy twice a day for four consecutive days in the last week of the experimental protocol); and group 4, A. vera + X-ray. X-ray exposure caused alterations in histoarchitecture of spleen along with enhanced clastogenic damage as assessed by micronucleus formation and apoptotic index. Irradiation caused an elevation in proinflammatory cytokines like tumor necrosis factor and interleukin-6, total leucocyte counts, neutrophil counts and decreased platelet counts along with unaltered red blood cell counts and hemoglobin. Irradiation also caused an elevation in reactive oxygen species (ROS), lipid peroxidation (LPO) levels, lactate dehydrogenase activity and alterations in enzymatic and nonenzymatic antioxidant defense mechanism in plasma and spleen. However, administration of A. vera gel extract ameliorated X-ray irradiation-induced elevation in ROS/LPO levels, histopathological and clastogenic damage. It also modulated biochemical indices, inflammatory markers, and hematological parameters. These results collectively indicated that the A. vera gel extract offers protection against whole-body X-ray exposure by virtue of its antioxidant, anti-inflammatory and anti-apoptotic potential.

Radioprotective effect of grape seed extract against gamma irradiation in mouse bone marrow cells.

INTRODUCTION: Ionizing radiations produce free radicals which are often responsible for DNA damage or cell death. Grape seed extract (GSE) is a natural compound having an antioxidant that protects DNA, lipids, and proteins from free radical damages. In this study, radioprotective effect of the GSE has been investigated in mouse bone marrow cells using micronucleus test. MATERIALS AND METHODS: Four groups of mice were investigated in this study: Mice in Group 1 were subjected to injection of distilled water with no irradiation. Mice in Group 2 were exposed to 3 Gy gamma radiation after the injection of distillated water. Mice in Group 3 were injected with 200 mg/kg of the GSE without any irradiation. In another group, mice were exposed to three gray gamma irradiation after the injection of GSE. Animals were killed, and slides were prepared from the bone marrow cells 24 h after irradiation. The slides were stained with May Grunwald-Giemsa method and analyzed microscopically. The frequency of the micronucleated polychromatic erythrocytes (MnPCEs), micronucleated normochromatic erythrocyte (MnNCEs), and polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte (PCE/PCE + NCE) ratios was calculated. RESULTS: Injection of GSE significantly decreased the frequency of MnPCEs (P < 0.0001) and MnNCEs (P < 0.05) and increased the ratio of PCE/PCE + NCE (P < 0.0001) compared to the irradiated control group. DISCUSSION AND CONCLUSIONS: GSE could reduce clastogenic and cytotoxic effects of gamma irradiation in mice bone marrow cells; therefore, it can be concluded that the GSE is a herbal compound with radioprotective effects against gamma irradiation. Free radical scavenging and the antioxidant effects of the GSE probably are responsible mechanisms for the GSE radioprotective effects.

In Vitro Anti-proliferative Activity and Mechanism of Action of Anemone nemorosa.

Anemone nemorosa is part of the Ranunculaceae genus Anemone (order Ranunculales) which comprises more than 150 species. Various parts of the plant have been used for the treatment of numerous medical conditions such as headaches, tertian agues, rheumatic gout, leprosy, lethargy, eye inflammation as well as malignant and corroding ulcers. The Anemone plants have been found to contain various medicinal compounds with anti-cancer, immunomodulatory, anti-inflammatory, anti-oxidant and anti-microbial activities. To date there has been no reported evidence of its use in the treatment of cancer. However, due to the reported abundance of saponins which usually exert anti-cancer activity via cell cycle arrest and the induction of apoptosis, we investigated the mode of cell death induced by an aqueous A. nemorosa extract by using HeLa cervical cancer cells. Cisplatin was used as a positive control. With a 50% inhibitory concentration (IC50) of 20.33 ± 2.480 µg/mL, treatment with A. nemorosa yielded a delay in the early mitosis phase of the cell cycle. Apoptosis was confirmed through fluorescent staining with annexin V-FITC. Apoptosis was more evident with A. nemorosa treatment compared to the positive control after 24 and 48 h. Tetramethylrhodamine ethyl ester staining showed a decrease in mitochondrial membrane potential at 24 and 48 h. The results obtained imply that A. nemorosa may have potential anti-proliferative properties.

Psathyrella candolleana and Agaricus bisporus Extracts Provide Protection against DNA Oxidative Damage Induced by Doxorubicin.

In this study, the aqueous extracts of fruiting bodies of Psathyrella candolleana and Agaricus bisporus were assessed in vitro for their genotoxic potential. Extracts of these 2 fungi were tested with regard to their capacity to protect genetic material against DNA damage caused by the anticancer chemotherapy drug, doxorubicin. Using chromosomal aberration, micronucleus, and comet assays, the genotoxic and genoprotective potential of these 2 fungi was assessed using P. candolleana strain RM-0861 and A. bisporus strain AB-62. Genetic damage was determined by the chromosomal aberration assay, and evaluation of oxidative damage was performed in vitro by the micronucleus test and comet assay. A significant decrease in micronucleus formation was noted in comparison with the corresponding control. None of the mushroom extract treatments in this study displayed genotoxicity or cytotoxicity. Significantly, the greatest reductions of chromosomal aberration were found with the extracts of P. condolleana for all time periods tested. The extracts tested showed a marked anticlastogenic effect against DNA damage, as evidenced by a decrease in the frequency of total breaks. The data obtained suggest that extracts of these fungi are anticlastogenic under the conditions tested. These results indicate that mushroom extracts contain bioactive compounds that may prevent oxidative DNA damage induces by doxorubicin, as measured by chromosomal aberration, comet and micronucleus assay.

Antigenotoxic effect of melatonin against mercuric chloride in human peripheral blood lymphocytes.

Melatonin (MLT) is an extraordinary antioxidant, which plays an important role in reducing reactive oxygen species (ROS) by scavenging them directly or indirectly. Mercury (Hg) is a heavy metal, which induces cytogenetic alterations via various mechanisms, leading to genotoxicity. It induces genotoxicity by enhancing the ROS chiefly. In the present study, the antigenotoxic effect of MLT was evaluated against mercuric chloride (HgCl2). All experiments were conducted in vitro in peripheral blood lymphocytes. Blood cultures were exposed to various concentrations of HgCl2 (2.63, 6.57, and 10.52 microM) for 24 h to study a range of genotoxic parameters. MLT (0.2 mM) supplementation, alone and in combination with the high concentration of Hg, was administered to blood cultures for 24 h. Genotoxic parameters, such as chromosomal aberrations (CAs; structural aberrations (chromatid gaps and breaks, chromosomal gaps and breaks) and numerical aberrations), micronuclei (MNs), and comet assay, were evaluated and analyzed using suitable statistical analysis. Hg treatment revealed a significant increase in CAs, MNs, and comet length. Co-supplementation of MLT along with Hg showed marked protection of these genotoxic end points in treated cultures. In conclusion, our findings suggest that MLT protects against Hg-induced augmentation in genotoxic indices because of its antioxidant property.

Genotoxicity evaluation of So-ochim-tang-gamibang (SOCG), a herbal medicine.

BACKGROUND: So-ochim-tang-gamibang (SOCG) is a traditional Korean medicine frequently used for depression in the clinical field. In this study, we evaluated the potential genotoxicity of SOCG using three standard batteries of tests as part of a safety evaluation. METHODS: SOCG was evaluated for potential genotoxic effects using the standard three tests recommended by the Ministry of Food and Drug Safety (MFDS) of Korea. These tests were the bacterial reverse mutation test (Ames test), in vitro mammalian chromosomal aberration test using Chinese hamster lung cells, and in vivo micronucleus test using ICR mice. RESULTS: The Ames test with Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 and the Escherichia coli strain WP2uvrA(pKM101) showed that SOCG did not induce gene mutations at any dose level in all of the strains. SOCG did not induce any chromosomal aberrations in the in vitro chromosomal aberration test (for both the 6 and 24 h test) and the in vivo micronucleus test. CONCLUSIONS: Based on the results of these tests, it was concluded that SOCG does not exhibit any genotoxic risk under the experimental conditions of this study.

Assessment of protective potential of Nigella sativa oil against carbendazim- and/or mancozeb-induced hematotoxicity, hepatotoxicity, and genotoxicity.

Nigella sativa oil (NSO) possesses antioxidant activity. However, its protective role against the hazards of fungicides has been poorly studied. Therefore, the present work aimed at determining the ameliorative potential of NSO against hepatotoxicity induced by carbendazim (CBZ) and/or mancozeb (MNZ) in female rats. In the present study, about 120 adult female Sprague-Dawley rats were randomly divided into eight equal groups. One group of animals was kept as a negative control (Gp. 1); groups 2, 3 and 4 orally received CBZ (200 mg/kg body wt) and/or MNZ (300 mg/kg body wt) daily for 2 weeks (positive groups). In order to assess the hepatoprotective potential of NSO, in comparison with NSO-treated rats (Gp. 5), groups 6, 7 and 8 were CBZ- and/or MNZ-exposed groups pre-treated orally with NSO (2 ml/kg body wt) daily for 2 weeks (prophylactic groups). All groups were kept further for 15 days without medications to observe the withdrawal effect. At the end of exposure and withdrawal periods, the body weight of all experimental rats was recorded and blood samples were collected for hematological, clinico-biochemical, and micronucleus assays. The animals were then sacrificed, and the liver and bone marrow were harvested for oxidative stress bioassay, chromosomal aberrations, DNA fragmentation, and histopathological examinations. The results suggested that pre-treatment with NSO remarkably diminished CBZ- and MNZ-induced macrocytic hypochromic anemia, leukocytosis, lymphocytosis, eosinophilia, and neutropenia. Besides, it also minimized the elevated liver enzymes, lipid peroxidation, micronucleus incidence, DNA damage, and chromosomal aberration frequency. Conversely, NSO significantly stimulated the CBZ- and/or MNZ-induced antioxidant system suppression. The NSO also normalized the hepatic structural architecture. As far as withdrawal effect is concerned, there was almost disappearance of the bad effects of these fungicides and the values were close to the normal range especially with the use of NSO. Ultimately, the results revealed that N. sativa oil is an effective hepatoprotective agent due to its genoprotective and free radical scavenging activities.

Protective effects of pomegranate peel against hematotoxicity, chromosomal aberrations, and genotoxicity induced by barium chloride in adult rats.

CONTEXT: Pomegranate peel (PP) has health benefits including antibacterial, antioxidant, anti-inflammatory, and antimutagenic properties. OBJECTIVE: This study investigated the biochemical composition and protective effects of PP against hematotoxicity and genotoxicity induced by barium chloride (BaCl2) in adult rats. MATERIALS AND METHODS: Adult Wistar rats were divided into four groups of six each: control, barium (67 ppm via drinking water), PP (5% via diet), and their combination during 21 d. Oxidative stress was determined by MDA, AOPP, and antioxidant status: CAT, GPx, GSH, Vit C. Osmotic fragility (OF), chromosomal aberrations (CAs), and micronucleus (MN) assays were also studied. RESULTS: PP showed a rich composition of antioxidant compounds. DPPH test found IC50 value= 5.3 µg/mL and a high polysaccharides content (315 ± 5 mg/g of extract). In vivo study showed a decrease in red blood cells (70%) and platelet counts (46%), hemoglobin content (8%), hematocrit percent (7%), and an 80% increase of white blood cells in Ba-treated rats. A reduction in antioxidant status: catalase, glutathione peroxidase activities, glutathione, and vitamin C levels by 31, 21, 28, and 29%, respectively, and an increase in MDA (46%) and AOPP levels (72%) were also observed compared with controls. BaCl2-treatment showed a significant increase in the frequencies of total chromosomal aberrations with abnormal metaphases and micronucleus in bone-marrow cells. Oxidative stress induced by BaCl2 might be the major cause for chromosomal abnormalities leading to DNA damage. DISCUSSION AND CONCLUSION: A decrease in hematotoxic and genotoxic effects induced by PP is due to its powerful antioxidant capacity.

Possible radioprotective effect of folic acid supplementation on low dose ionizing radiation-induced genomic instability in vitro.

Ionizing radiation (IR) induces DNA damage through production of single and double-strand breaks and reactive oxygen species (ROS). Folic acid (FA) prevents radiation-induced DNA damage by modification of DNA synthesis and/or repair and as a radical scavenger. We hypothesized that in vitro supplementation with FA will decrease the sensitivity of cells to genetic damage induced by low dose of ionizing radiation. Annexin V, comet and micronucleus assays were performed in cultured CHO cells. After 7 days of pre-treatment with 0, 100, 200 or 300 nM FA, cultures were exposed to radiation (100 mSv). Two un-irradiated controls were executed (0 and 100 nM FA). Data were statistically analyzed with X2-test and linear regression analysis (P 0.05). We observed a significantly decreased frequency of apoptotic cells with the increasing FA concentration (P <0.05). The same trend was observed when analyzing DNA damage and chromosomal instability (P <0.05 for 300 nM). Only micronuclei frequencies showed significant differences for linear regression analysis (R2=94.04; P <0.01). Our results have demonstrated the radioprotective effect of folic acid supplementation on low dose ionizing radiation-induced genomic instability in vitro; folate status should be taken into account when studying the effect of low dose radiation in environmental or occupational exposure.

Analysis of the anti-inflammatory and chemopreventive potential and description of the antimutagenic mode of action of the Annona crassiflora methanolic extract.

CONTEXT: Annona crassiflora Mart. (Annonaceae) is a medicinal plant that is widely used in folk medicine, which leads to its investigation as a potential source of new pharmacological principles. OBJECTIVE: This study describes the anti-inflammatory, antiallodynic, and antimutagenic/chemopreventive activities of the leaves A. crassiflora methanolic extract. Its antimutagenic mode of action was analyzed in a plant or animal experimental model. MATERIALS AND METHODS: Total flavonoids were quantified by spectrophotometry at 415 nm and its composition was analyzed by (1)H NMR spectra. Animals received orally, 30, 100, and 300 mg/kg of extract in both tests, carrageenan-induced paw edema and myeloperoxidase activity. Animals were treated with 100 and 300 mg/kg, in all the analyzed tests, pleural cell migration and protein exudation, carrageenan-induced cell migration into the pouch, induction of joint inflammation and carrageenan-induced allodynia response in the mouse paw. To evaluate the antimutagenic/chemopreventive activity through the Allium cepa test, we used 5, 10, and 15 mg/L of extract, and for the micronucleus test in the peripheral blood, we used the dose of 15 mg/kg. RESULTS: The fractionation of the ethyl acetate (EA) fraction, resulting from the partition of the methanol extract of the A. crassiflora, afforded through chromatographic methods resulted in the isolation of kaempferol 3-O-ß-glucoside and kaempferol 3-O-ß-diglucoside. Oral treatment with 100 and 300 mg/kg of extract significantly inhibited the carrageenan-induced edema formation, with inhibitions of 53 ± 7% and 47 ± 10%; in MPO activity, the observed inhibitions were 60 ± 7% for 100 mg/kg treatment and 63 ± 7% for 300 mg/kg. The ACME reduced significantly the total leukocytes (an inhibition of 78 ± 9% with 100 mg/kg and 90 ± 7% with 300 mg/kg) and protein levels (approximately 100% inhibition with both doses) in the pleurisy model. In carrageenan-induced leukocyte migration into the pouch, the extract inhibited leukocyte migration only when administered 300 mg/kg per dose (the reduction was 43 ± 5%). Pretreatment with extract failed to reduce the zymosan-induced edema formation and did not inhibit the carrageenan-induced mechanical allodynia. Damage reduction in Allium cepa tested with different concentrations (5, 10, and 15 mg/L) was 66.17, 75.75, and 69.19% for the pre-treatment; 72.72, 33.33, and 22.22% for the simple simultaneous treatment; 100.50, 93.93, and 102.52% for the simultaneous treatment with pre-incubation; 89.39, 79.79, and 84.34%; for the post-treatment, and 86.36, 81.31, and 93.43% for the continuous treatment. The antimutagenic evaluation in the micronucleous test showed a damage reduction of 75.00 and 64.58% for the pre-treatment and simultaneous protocols, respectively. The post-treatment protocol increased the cyclophosphamide effects in 45.83%. CONCLUSION: These results suggest that this medicinal plant has chemopreventive and anti-inflammatory therapeutic potential.

The micronucleus assay in mammalian cells in vitro to assess health benefits of various phytochemicals.

We evaluated the protective effects of Gentiana lutea extracts (GLEx) and 6-Gingerol (6-G) on clastogenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 7,12-dimethylbenz(α) anthracene (DMBA) in vitro on HepG2 cells using the frequencies of induced micronuclei (MN) as the end point. Pre-, post- and simultaneous treatments with GLEx or 6-G and the carcinogens were carried out. Both GLEx post- and simultaneous treatments reduced the frequencies of MN induced by MNNG and DMBA. Probably this effect is due to an increase of cytostasis and a physico-chemical interaction between GLEx and DMBA under simultaneous treatment. Pre- and simultaneous treatments with 6-G significantly reduced the yield of MNNG-induced micronuclei without affecting % of cytostasis. Simultaneous treatment with 6-G plus DMBA resulted in reduction in the frequency of MN and an increase in cytotoxicity compared to sample treated alone with DMBA, whereas a post-treatment, caused a significant decrease in the yield of MN compared with DMBA alone without any cytotoxic effect. These results are compared with our earlier data obtained in the same system with other phytochemicals. It is concluded that for a critical evaluation of the protective effects of phytochemicals, both the influence on the induced MN and induced cytostasis have to be considered.

[THE EFFECT OF PLANT EXTRACTS ON THE CYCLOPHOSPHAMIDE INDUCTION OF MICRONUCLEUS IN RED BLOOD CELLS OF OUTBRED WHITE MICE].

Antimutagenic properties flavonoids extracts of the three plants Gratiola officinalis L., Helichrysum arenarium L., anthocyanin forms Zea mays L. were investigated. Analysis was performed by counting the micronucleus in peripheral blood erythrocytes outbred white mice; the mutagen was cyclophosphamide. Selected extracts reduce the number of micronucleus. Gratiola officinalis L. extract reduces the mutagenic action of cyclo- phosphamide at a dose of 200 mg/kg, Helichrysum arenarium L. extract--at doses of 100 and 200 mg/kg (maximum protective effect was observed at a dose of 200 mg/kg), anthocyanin forms Zea mays L. extract at doses of 50, 100 and 200 mg/kg (a dose of 50 mg/kg--maximum antimutagenic effect).

Influence of selenium on radiogenic collagen destruction and the degree of collagen tissue maturation in stage III oral squamous cell carcinoma patients undergoing therapeutic irradiation.

INTRODUCTION: We set out to assess whether selenium, an antioxidant mineral could influence radiogenic collagen maturation. MATERIALS AND METHODS: The study comprise of normal (Group I), untreated oral carcinoma cases (Group II) (n = 20), cases who underwent radiotherapy (Group IIa) n = 10 and cases supplemented with selenium along with radiotherapy (Group IIb) n = 10. RESULTS: Spectrophotometric estimation and luminescence spectral assignment of collagen showed improved collagen maturation status. Measurement of the mature collagen cross-links hydroxylysylpyridinoline and lysylpyridinoline by high-performance liquid chromatography on irradiated tissues showed a considerable decrease in the selenium Group IIb (P < 0.05) indicating a decrease in collagen fragments. Electron microscopic studies showed significant morphological alteration in the selenium group. The micro nucleus frequency, decreased in radiation group (P < 0.05) compared with untreated (P < 0.05). While much more decrease observed in the selenium group (P < 0.05). DISCUSSION: The results represent the effect of selenium treatment with a bearing on carcinogenic process to curtail it, thus enhancing the maturity of collagen.

Micronucleated erythrocytes in newborns of rat dams exposed to ultraviolet-A light during pregnancy; protection by ascorbic acid supplementation.

Pregnant hairless rat dams were exposed to ultraviolet-A light (UVA) to induce micronucleated erythrocytes (MNE) in their fetuses. The control group was exposed to conventional light; the experimental groups were exposed to UVA (365nm) during gestational days 16-21. In some cases, ascorbic acid (Asc) was administered in the drinking water from gestational day 15 until delivery. Dams were sampled at 48-h intervals during gestation, from day 16 until delivery. Blood was also obtained from neonates at birth; MNE, micronucleated polychromatic erythrocytes (MNPCE), and polychromatic erythrocytes (PCE) were scored. Increased MNE and MNPCE were observed in neonates born to mothers exposed to UVA for 40, 80 or 160min, compared to the control group. Asc treatment reduced MNE and MNPCE induction.

Purple rice bran extract attenuates the aflatoxin B1-induced initiation stage of hepatocarcinogenesis by alteration of xenobiotic metabolizing enzymes.

Pigmented rice bran has been suggested to be a valuable source of beneficial phytochemicals. We investigated genotoxic and anti-genotoxic effects of purple rice bran extract (PRBE) in rats using a liver micronucleus assay. Purple rice bran was extracted with methanol, obtaining large amounts of phenolic compounds, including anthocyanins and small amounts of gamma-oryzanol. The experimental protocols were divided into two sets. Male rats were divided into three groups. Group 1 was a negative control, while Groups 2 and 3 were fed with 100 and 500 mg/kg bw of PRBE, respectively, for 28 days. PRBE had no effect on micronucleus formation or xenobiotic metabolizing enzymes in rat liver. Experiments concerning the effect of PRBE on AFB1 showed that PRBE significantly lessened the amount of micronucleated hepatocytes in AFB1 treated rats. Furthermore, it modulated metabolic activation of AFB1 metabolism in the liver by suppressing activity and protein expression of CYP1A2, CYP3A and CYP 450 reductase, and enhancing phase II enzymes including GST and UGT. Overall, purple rice bran extract was not genotoxic in rats. It exhibited anti-genotoxicity by modulation some xenobiotic enzymes active in AFB1 metabolism.

MWCNT uptake in Allium cepa root cells induces cytotoxic and genotoxic responses and results in DNA hyper-methylation.

Advances in nanotechnology have led to the large-scale production of nanoparticles, which, in turn, increases the chances of environmental exposure. While humans (consumers/workers) are primarily at risk of being exposed to the adverse effect of nanoparticles, the effect on plants and other components of the environment cannot be ignored. The present work investigates the cytotoxic, genotoxic, and epigenetic (DNA methylation) effect of MWCNT on the plant system- Allium cepa. MWCNT uptake in root cells significantly altered cellular morphology. Membrane integrity and mitochondrial function were also compromised. The nanotubes induced significant DNA damage, micronucleus formation and chromosome aberration. DNA laddering assay revealed the formation of internucleosomal fragments, which is indicative of apoptotic cell death. This finding was confirmed by an accumulation of cells in the sub-G0 phase of the cell cycle. An increase in CpG methylation was observed using the isoschizomers MspI/HpaII. HPLC analysis of DNA samples revealed a significant increase in the levels of 5-methyl-deoxy-cytidine (5mdC). These results confirm the cyto-genotoxic effect of MWCNT in the plant system and simultaneously highlight the importance of this epigenetic study in nanoparticle toxicity.