In vivo effect of chlorophyllin on gamma-ray-induced sister chromatid exchange in murine bone marrow cells

Normalization of nano-sized TiO2-induced clastogenicity, genotoxicity and mutagenicity by chlorophyllin administration in mice brain, liver, and bone marrow cells

The intensive uses of titanium dioxide (TiO2) nanoparticles in sunscreens, toothpaste, sweats, medications, etc. making humans exposed to it daily by not little amounts and also increased its risks including genotoxicity. Thus, the present study was designed as one way to reduce nano-titanium-induced clastogenicity, genotoxicity, and mutagenicity in mice by co-administration of the free radical scavenger chlorophyllin (CHL). In addition, markers of oxidative stress were detected to shed more light on mechanism(s) underlying nano-sized TiO2 genotoxicity. Male mice were exposed to multiple injection into the abdominal cavity for five consecutive days with either CHL (40 mg/kg bw/day), or each of three dose levels of nano-sized TiO2 (500, 1000, or 2000 mg/kg bw/day) alone, or both simultaneously and sacrificed by cervical dislocation 24 h after the last treatment. After CHL co-administration, the observed dose-dependent genotoxicity of TiO2 nanoparticles indicated by the significant elevations in frequencies of both micronuclei and DNA damage induction was significantly decreased and returned to the negative control level. The observed induced mutations in p53 exons 5, 7, & 8 and 5 & 8 in the liver and brain, respectively, were declined in most cases. Moreover, CHL significantly decreased hepatic malondialdehyde level and significantly increased glutathione level and superoxide dismutase, catalase, and glutathione peroxidase activities that were significantly disrupted in animal groups treated with nano-TiO2 alone. In conclusion, the evidenced in vivo genotoxicity of nano-TiO2 in the present study was normalized after CHL co-administration which supports the previously suggested oxidative stress as the possible mechanism for titanium toxicity.

Effect of chlorophyllin against oxidative stress in splenic lymphocytes in vitro and in vivo

Chlorophyllin (CHL) has been examined as an antioxidant/radioprotector in splenic lymphocytes from BALB/c mice. CHL inhibited lipid peroxidation induced by 2,2'-azobis(2-propionimidinedihydrochloride) (AAPH) in lymphocytes in vitro. It also partially prevented radiation-induced suppression of mitogenic stimulation of lymphocytes in vitro. Generation of intracellular reactive oxygen species (ROS) by radiation or AAPH was measured as oxidation of dichlorodihydrofluorescein diacetate (H(2)DCF-DA) using flow cytometry. Addition of CHL to lymphocytes in vitro significantly inhibited the increase in intracellular ROS. Further, lymphocytes from mice treated with CHL (100-400 microg/gbw i. p.) showed varying levels of ROS depending on the dose and the time (24 to 72 h) after injection. The extent of radiation-induced apoptosis and suppression of concanavalin A (con A)-induced mitogenesis ex vivo corresponded with changes in ROS levels in CHL-administered mice. Antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) were also estimated in lymphocytes from CHL-treated mice. CHL offered protection against whole body irradiation (WBI)-induced lipid peroxidation and apoptosis in lymphocytes at all the time points studied. These results demonstrate antioxidant effect of CHL in vivo.

Anticlastogenicity of chlorophyllin in the different cell cycle phases in cultured mammalian cells

Chlorophyllin (Chln), a sodium-copper salt derivative of chlorophyll, like chlorophyll-a and -b found in green plants, has been studied for its protective action against the carcinogenic effects of various physical and chemical agents and in relation to the mutagenic and clastogenic activities of genotoxic agents. The aim of the present study was to evaluate chlorophyllin in different phases of the cell cycle for clastogenicity and anticlastogenicity, the latter in reversing DNA damage induced by ethyl methane sulfonate (EMS). The test for chromosomal aberrations was performed in cultured mammalian cells (CHO-K1). The three Chln concentrations tested (6.25, 12.5 and 25 microg/ml) were not clastogenic and damage induced by EMS (1240 microg/ml) was reduced in cells treated with Chln as well during S (25-48%) and G2/S (70-80%). The results demonstrate a greater protective effectiveness of Chln against EMS during G2/S.

Effects of chlorophyllin on mouse embryonic and fetal development in vivo

Chlorophyllin (CHL) has proven that there is antimutagenic and anticarcinogenic activity in several organisms without causing lethal effects. However, there is no information about its effects when it is administered in gestation. In the present study, we assessed possible effects of CHL when it was administered to CD-1 mice on the 8th day of gestation using the same doses and administration route used in ours previous antimutagenic and antigenotoxic studies. Females were exposed to a single dose of CHL by i.p. injection (20, 40, 50, or 100mg/kg b.w.). On day 18 all dams were subjected to cesarean section and the fetuses were examined with common teratological methods. Results show that CHL-treatment induced total litter loss and is dose-dependent, probably due to either the interaction between CHL and some general control mechanisms of embryo development or by an impairment of maternal-fetal interactions. The analysis of uterine horns of the CHL-treated females with total litter loss revealed the presence of green rings in the uterus. Results show the inverse relationship between the number of live implants and the frequency of green rings, indicating implantation sites where embryo death and early resorptions occurred. Although CHL was given in a single dose on day 8 in this study, the results indicate that CHL is associated with significant embryo lethality.

Anticlastogenic effect of Spirulina maxima extract on the micronuclei induced by maleic hydrazide in Tradescantia

The aim of this investigation was to determine if extracts of Spirulina maxima reduce the genotoxic damage induced by maleic hydrazide (MH) using the Tradescantia biosssay. Two types of extracts from the alga were prepared: an aqueous extract with two different concentrations, 100 and 500 mg/ml, and a second one, the extract of a 1% solution of dimethyl sulfoxide (DMSO) which corresponded to 100 mg/ml of the alga. The capacity of MH to induce micronuclei (MN) was initially established by administering 0.005, 0.01, and 0.015 mg/ml of the chemical to the Tradescantia inflorescences, and observing its effect after 24 h.The results of this experiment showed a significant MN increase with the two high concentrations tested, although no dose-response effect was observed. For the anticlastogenic assay, the extracts of Spirulina were applied to the inflorescences alone or immediately before the application of MH (0.01 mg/ml) and the induced MN were observed 24 h later. We found that none of the extracts increased the MN level with respect to the untreated plants; also, that MH more or less doubled the basal micronuclei frequency, and finally, that all tested extracts reduced the genotoxic damage caused by MH. The inhibitory indices obtained for the aqueous extracts (100 and 500 mg/ml) and for the DMSO extract were respectively 59, 85, and 56.3%. These data indicate that Spirulina is an anticlastogenic agent and suggest that it is advisable to extend studies on this matter using other biological models.

Effect of chlorophyllin on chromium trioxide-induced micronuclei in polychromatic erythrocytes in mouse peripheral blood

The effect of chlorophyllin on micronucleated polychromatic erythrocytes (MN-PCE) induction by chromium trioxide (CrO(3)) exposure in peripheral blood of mice was studied. Animals were treated with a single intraperitoneal dose of chlorophyllin (CHL) (20mg/kg), CrO(3) (20mg/kg), and CHL (20mg/kg) 4h before (CHL-CrO(3)) or 4h before and 20h after chromium treatments (20mg/kg; CHL-CrO(3)-CHL). Peripheral blood samples were drawn from the caudal vein at 0, 12 and 48h, and analyzed by the acridine orange (AO) technique. The results obtained in present study shown that CHL injection did not modify the number of MN-PCE. CrO(3) treatment resulted in a significantly increases 12 and 48h after the injection, reaching a four-fold increase 48h after CrO(3) administration. Whereas treatment with 20mg/kg of CHL prior to chromium, decreased the MN frequency induced by chromium in the 12h samples. When the samples were analyzed 48h after CrO(3) injection, no significant differences between CHL-CrO(3) and CHL-CrO(3)-CHL in comparison with CrO(3) treatment, were observed. These results indicate that increase of MN-PCE by CrO(3) is CHL-blocked in both protocols used (CHL-CrO(3) and CHL-CrO(3)-CHL) at 12h after treatment, but it was unable to modify the frequency of MN-PCE measured 48h after CrO(3) injection. The absence of a protective effect by CHL in the MN-PCE induction by CrO(3) at 48h, show that CHL has action only on one of the times of MN induction and suggests the possible action of CrO(3) by two different mechanisms, and not by CHL time-limited in vivo.

Inhibition of radiation-induced DNA damage in plasmid pBR322 by chlorophyllin and possible mechanism(s) of action

Naturally occurring compounds capable of protecting DNA against ionizing radiation and chemical mutagens have considerable potential for prevention of mutation-based health impairment including cancer and other degenerative diseases. Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, has been examined for its ability to protect DNA against radiation induced strand breaks using an in vitro plasmid DNA system. Gamma-radiation, up to a dose of 6 Gy (dose rate 1.25 Gy/min), induced a dose-dependent increase in single-strand breaks (ssbs) in plasmid pBR322 DNA. CHL per se did not induce, but inhibited radiation-induced ssbs in a concentration-dependent manner; 500 microM giving about 90% protection. The protection afforded by CHL was comparatively less than that of trolox, a water-soluble analogue of alpha-tocopherol. To elucidate the underlying mechanism(s), reaction of CHL with the radiation-derived hydroxyl radical (.OH) and deoxyribose peroxyl radical (ROO.) was studied by pulse radiolysis. CHL exhibited a rate constant of 6.1+/-0.4x109 M-1 s-1 with.OH and 5.0+/-1.3x107 M-1 s-1 with ROO. To our knowledge, this is the first report providing direct evidence of free radical-scavenging properties of CHL. The results showed that CHL, effectively protects plasmid DNA against ionizing radiation, in an in vitro system independent of DNA repair or other cellular defense mechanisms. The ability of CHL to scavenge. OH and ROO., may contribute to its protective effects against radiation induced DNA damage in the pBR322 system.

Different effects of newly isolated saponins on the mutagenicity and cytotoxicity of the anticancer drugs mitomycin C and bleomycin in human lymphocytes

Aim of the present paper was to assess by using the in vitro micronucleus (MN) test in human lymphocytes the effect of two plant extracts isolated from Blupeurum fruticosum (saponins) on the clastogenicity and cytotoxicity of the anticancer drugs mitomycin C (MMC) and bleomycin (BLM). One saponin showed a dose-dependent MMC-induced mutagenesis inhibition together with co-genotoxic effect on BLM-treated cultures. The remaining saponin did not significantly alter MN induction of both chemotherapeutic agents whereas it enhanced BLM cytotoxicity.

Inhibitory effect of chlorophyllin on the frequency of sister chromatid exchanges produced by benzo[a]pyrene in vivo

The study was designed to determine the antigenotoxic potential of chlorophyllin (Chl), against the frequency of sister-chromatid exchanges (SCE) produced by benzo[a]pyrene (B[a]P) in vivo. We used the mouse bone marrow test system to measure the effect of a single injection of the compounds: 40 mg/kg of B[a]P, and 1 h later, 1.0, 2.0, 4.0 and 8.0 mg/kg of Chl. As controls we included both chemicals using the dosages mentioned above as well as mineral oil (0.25 mg/kg). The results indicated the following: (1) Chl per se was not genotoxic, showing SCE values in the range of the control level; (2) B[a]P increased the rate of SCEs three times in relation to the basal level; (3) the SCE level produced with B[a]P was diminished by all 4 doses of Chl, but better results were obtained with 2-4 mg/kg, a range which induced Inhibition Indices of 80.9% and 77.5% respectively; (4) the Average Generation Time Index was not modified by the compounds used in the experiment; and (5) the Mitotic Index also showed no significant modification induced by the chemicals, with respect to the control value.

Effect of chlorophyllin on gamma ray induced micronuclei in polychromatic erythrocytes of murine peripheral blood determined by the ABC strategy

The effect of chlorophyllin on micronucleated polychromatic erythrocyte (MN-PCE) induction by gamma ray exposure in peripheral blood of mice was studied. The area beneath the curve (ABC) of MN-PCE frequency versus time was used as an index of total MN-PCE induction. The dose of 200 mg chlorophYllin per kg of body weight caused a slight, but not significant, reduction of the MN-PCE caused by 1.0 Gy exposure. This result indicates that chlorophyllin did not protect the cells against MN induction. In previous studies it was observed that the same chlorophyllin dose was able to protect 100% against sister chromatid exchange (SCE) induction by 1.0 gamma rays in both murine spermatogonia and bone marrow cells. These contradictory results indicate that chlorophyllin did not protect cells by scavenging free radicals, but by other mechanism, i.e. stimulating repair of lesions involved in SCE induction.

In vivo radioprotective effect of chlorophyllin on sister chromatid exchange induction in murine spermatogonial cells

The radioprotective capacity of chlorophyllin was determined by measuring the reduction of gamma-ray-induced sister chromatid exchange (SCE) in murine spermatogonia in vivo. The results obtained in experiments using 100 and 200 micrograms of chlorophyllin per gram of body weight (bw) and irradiated either before or after BrdU incorporation, indicate that a chlorophyllin dose of 200 micrograms/g bw protects 100% against the induction of SCE by 0.75 Gy of gamma-rays and 100 micrograms/g bw protects less than 50%. Chlorophyllin per se did not have any effect on the SCE frequency.