Chlorophyll and chromosome breakage
08 Aug 1996-Mutation Research\/environmental Mutagenesis and Related Subjects (Elsevier)-Vol. 360, Iss: 3, pp 187-191
TL;DR: It is observed that while a crude aqueous extract of Indian spinach leaf significantly reduced genotoxic effects, chlorophyll alone was ineffective and induced a significantly high frequency of chromosome breaks in bone marrow cells of mice on oral administration.
Abstract: Increased consumption of green vegetables in the diet has been associated with protection against carcinogenic effects and related mutagenic and clastogenic (chromosome breaking) activity of genotoxic agents. Chlorophyll, present in all green plant parts, has been suggested to be a major protective factor in the process. We have, however, observed that while a crude aqueous extract of Indian spinach leaf significantly reduced genotoxic effects, chlorophyll alone was ineffective. On the other hand, chlorophyll, both as an aqueous extract from the leaf and in a purified commercial form, induced a significantly high frequency of chromosome breaks in bone marrow cells of mice on oral administration. The crude aqueous extract of the leaf was non-toxic. The protective activity of the crude leaf extract may be attributed to the total effect of the interaction between different components, in which the clastogenicity of chlorophyll has been neutralized.
TL;DR: In this in vitro SCG assay, PY, BaP and CP were positive with exogeneous metabolic activation while 4NQO, BLM, MMC, MTC, hydrogen peroxide, and diepoxbutane were positive in the absence of metabolic activation, supporting the sensitivity and specificity of this assay for identifying genotoxic agents.
Abstract: To validate the alkaline single cell gel (SCG) assay as a tool for the detection of DNA damage in human leukocytes, we investigated the in vitro activity of 18 chemicals. Thirteen of these chemicals (pyrene (PY), benzo(a)pyrene (BaP), cyclophosphamide (CP), 4-nitroquinoline-1-oxide (4NQO), bleomycin (BLM), methylmercury chloride (MMC), mitomycin C (MTC), hydrogen peroxide (HP), diepoxybutane (DEB), glutaraldehyde (GA), formaldehyde (FA), griseofulvin (GF), sodium azide (NA)) are genotoxic in at least one cell system, while five compounds (ascorbic acid (AA), glucose (GL), D-mannitol (MAN), O-vanillin (VAN), chlorophyllin (CHL)) are classified as non-genotoxic. In this in vitro SCG assay, PY, BaP and CP were positive with exogeneous metabolic activation (rat S9 mix) while 4NQO, BLM, MMC, MTC, hydrogen peroxide, and diepoxbutane were positive in the absence of metabolic activation. CHL and VAN were unexpectedly found to induce a dose-dependent increase in DNA migration. AA, GL, and MAN were negative in a non-toxic range of doses. GF gave equivocal results, while FA and GA increased DNA migration at low doses and decreased DNA migration at higher doses. This behaviour is consistent with the known DNA damaging and crosslinking properties of these compounds. These data support the sensitivity and specificity of this assay for identifying genotoxic agents.
TL;DR: A comprehensive overview of the health benefits and potential medicinal applications of these pigments and the future directions of research in these fields are provided.
Abstract: BACKGROUND & OBJECTIVE Thylakoids and chloroplasts harbor several vital metabolic processes, but are most importantly associated with photosynthesis. The undisturbed functioning of this process necessitates the ceaseless synthesis of photosynthetic pigments, including closed tetrapyrroles such as chlorophylls (Chls). Chls probably represent the most abundant natural pigment molecules which are via photosynthesis not only crucial for the autotrophic production of food sources for heterotrophic organisms but have also contributed to oxygen production essential for aerobic metabolism. This review first briefly discusses the physico-chemical properties, biosynthesis, occurrence, in vivo localization and roles of the different Chl pigments. Then we provide a detailed overview of their potential applications in the food industry and medicine. These include the use of Chls and their derivatives (different chlorophyllins) as food colorants (identified as E140 and E141 in the European Union). METHOD Different sources used for industrial extraction as well as different factors influencing pigment stability during processing are also critically reviewed. The problems surrounding the nomenclature, the production and the composition of different chlorophyllin mixtures are also discussed. RESULTS & CONCLUSION Finally, a comprehensive overview of the health benefits and potential medicinal applications of these pigments and the future directions of research in these fields are provided.
TL;DR: A high performance liquid chromatography-mass spectrometry (HPLC-MS) method for determination of chlorophylls and their derivatives in Gynostemma pentaphyllum Makino, a traditional Chinese herb possessing vital biological activities.
Abstract: The objectives of this study were to develop a high performance liquid chromatography-mass spectrometry (HPLC-MS) method for determination of chlorophylls and their derivatives in Gynostemma pentaphyllum Makino, a traditional Chinese herb possessing vital biological activities Chlorophylls were extracted with a quaternary solvent system of hexane-acetone-ethanol-toluene (10:7:6:7, v/v/v/v), followed by separation of a total of 15 chlorophylls and their derivatives within 32 min using a gradient mobile phase of acetone, acetonitrile and methanol and a HyPURITY C18 column, with detection at 660 nm and flow rate at 1 mL/min Identification was carried out on the basis of retention behavior, absorption spectra and mass spectra using atmospheric pressure chemical ionization (APCI) in positive ion mode for detection Of the 15 analytes, chlorophyll a, chlorophyll b, pheophytin a and pheophytin b were quantified by using standard calibration curves, with the other 11 being quantified with an internal standard Fast Green FCF Chlorophyll extracts in G pentaphyllum were found to contain pheophytin a (25083 microg/g), pheophytin a' (1112 microg/g), chlorophyll a (1138 microg/g), chlorophyll a' (110 microg/g), hydroxypheophytin a (886 microg/g), hydroxypheophytin a' (665 microg/g), pyropheophytin a (760 microg/g), hydroxychlorophyll a (238 microg/g), pheophytin b (3196 microg/g), pheophytin b' (132 microg/g), chlorophyll b (2879 microg/g), chlorophyll b' (111 microg/g), hydroxychlorophyll b (150 microg/g), hydroxypheophytin b (112 microg/g) and hydroxypheophytin b' (85 microg/g)
TL;DR: 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 byCHL time-limited in vivo.
Abstract: 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) (20 mg/kg), CrO 3 (20 mg/kg), and CHL (20 mg/kg) 4 h before (CHL–CrO 3 ) or 4 h before and 20 h after chromium treatments (20 mg/kg; CHL–CrO 3 –CHL). Peripheral blood samples were drawn from the caudal vein at 0, 12 and 48 h, 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 48 h after the injection, reaching a four-fold increase 48 h after CrO 3 administration. Whereas treatment with 20 mg/kg of CHL prior to chromium, decreased the MN frequency induced by chromium in the 12 h samples. When the samples were analyzed 48 h 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 12 h after treatment, but it was unable to modify the frequency of MN-PCE measured 48 h after CrO 3 injection. The absence of a protective effect by CHL in the MN-PCE induction by CrO 3 at 48 h, 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.
TL;DR: The decrease in risk the authors found associated with frequent ingestion of vegetables, and especially cabbage, Brussels sprouts, and broccoli, is consistent with the decreased numbers of tumors observed in animals challenged with carcinogens and fed compounds found in these same vegetables.
Abstract: We examined the diets as reported in interviews of 256 white male patients with cancer of the colon and of 330 white male patients with cancer of the rectum. Controls were 783 patients with nonneoplastic, nondigestive system diseases distributed by age similarly to the colon cancer patients and 628 patients with nonneoplastic, nondigestive diseases distributed by age like those with cancer of the rectum. We found no increase in risk for cancer of the colon or rectum regardless of the amounts of beef or other meats ingested. However, we found an increase in risk of colon cancer with decreases in the frequency with which vegetables were eaten. A study of 214 females with cancer of the colon and 182 females with cancer of the rectum yielded similar results. The decrease in risk we found associated with frequent ingestion of vegetables, and especially cabbage, Brussels sprouts, and broccoli, is consistent with the decreased numbers of tumors observed in animals challenged with carcinogens and fed compounds found in these same vegetables.
TL;DR: In this chapter, inhibitors of mutagenesis and carcinogenesis that can arise as components of diet have been reviewed and most of the inhibitors have been demonstrated to be effective against a specific class of mutagens or carcinogens.
Abstract: Dietary inhibitors of mutagenesis and carcinogenesis are of particular interest because they may be useful for human cancer prevention. Several mutagenesis inhibitors have been demonstrated to be carcinogenesis inhibitors also, e.g., ellagic acid, palmitoleic acid, and N-acetylcysteine. This means that the search for mutagenesis inhibitors may be useful for discovering anticarcinogenic agents. Many mutagenesis inhibitors have been discovered by the use of short-term assays, particularly the Ames Salmonella test. This simple in vitro system has provided opportunities to elucidate the mechanisms of inhibition. The elucidation of the mechanism may allow us to infer the possible anticarcinogenic activity of the reagent. In this chapter, inhibitors of mutagenesis and carcinogenesis that can arise as components of diet have been reviewed. Most of the inhibitors have been demonstrated to be effective against a specific class of mutagens or carcinogens. Therefore, it may be argued that these inhibitors are antagonistic only to those particular agents. Here again, understanding of the mechanisms of these inhibitions is necessary for the assessment. Dietary inhibitors reviewed in this article include: (1) as inhibitors of mutagenesis: porphyllins, fatty acids, vitamins, polyphenols, and sulfhydryl compounds, (2) as inhibitors of carcinogenesis: vitamins A, E and C, ellagic acid, sulfhydryl compounds, fats, selenium, calcium, and fiber. Further studies in this area of science appear to help establish the recipe of a healthy diet.