An assessment of the carcinogenic potential of shea oleine in the rat

AbstractThe purpose of this paper is to report on an expert system in design that screens for potential hazards from environmental chemicals on the basis of structure-activity relationships in the study of chemical carcinogenesis, particularly with respect to analyzing the current state of known structural information about chemical carcinogens and predicting the possible carcinogenicity of untested chemicals. The structure-activity tree serves as an index of known chemical structure features associated with carcinogenic activity. The basic units of the tree are the principal recognized classes of chemical carcinogens that are subdivided into subclasses known as nodes according to specific structural features that may reflect differences in carcinogenic potential among chemicals in the class. An analysis of a computerized data base of known carcinogens (knowledge base) is proposed using the structure-activity tree in order to test the validity of the tree as a classification scheme (inference engine).

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Less Carcinogenic Chlorinated Estrogens Applicable to Hormone Replacement Therapy

International Journal of Molecular Sciences ◽

10.3390/ijms22137222 ◽

2021 ◽

Vol 22 (13) ◽

pp. 7222

Author(s):

Yoshinori Okamoto ◽

Hideto Jinno ◽

Shinji Itoh ◽

Shinya Shibutani

Keyword(s):

Hormone Replacement Therapy ◽

Replacement Therapy ◽

Hormone Replacement ◽

Metabolic Activation ◽

Ovariectomized Rats ◽

Estrogenic Potential ◽

Carcinogenic Potential ◽

Induced Tumors ◽

Carcinogenic Effects ◽

17Β Estradiol

Human estrogens prescribed for hormone replacement therapy (HRT) are known to be potent carcinogens. To find safer estrogens, several chlorinated estrogens were synthesized and their carcinogenic potential were determined. A pellet containing either 2-chloro-17β-estradiol (2-ClE2) or 4-chloro-17β-estradiol (4-ClE2) was implanted subcutaneously for 52 weeks into August Copenhagen Irish (ACI) rats, a preferred animal model for human breast cancer. 17β-Estradiol (E2) frequently induced mammary tumors while both 2-ClE2 and 4-ClE2 did not. Their 17α-ethinyl forms, thought to be orally active estrogens, were also synthesized. Neither 2-chloro-17α-ethinylestradiol (2-ClEE2) nor 4-chloro-17α-ethinylestradiol (4-ClEE2) induced tumors. The less carcinogenic effects were supported by histological examination of mammary glands of ACI rats treated with the chlorinated estrogens. A chlorine atom positioned at the 2- or 4-position of E2 may prevent the metabolic activation, resulting in reducing the carcinogenicity. 2-ClE2 and 4-ClE2 administered subcutaneously and 2-ClEE2 and 4-ClEE2 given orally to ovariectomized rats all showed uterotrophic potency, albeit slightly weaker than that of E2. Our results indicate that less carcinogenic chlorinated estrogens retaining estrogenic potential could be safer alternatives to the carcinogenic estrogens now in use for HRT.

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Carcinogenic potential of formaldehyde in occupational settings: a critical assessment and possible impact on occupational exposure levels

International Archives of Occupational and Environmental Health ◽

10.1007/s00420-007-0241-9 ◽

2007 ◽

Vol 81 (6) ◽

pp. 695-710 ◽

Cited By ~ 24

Author(s):

S. Duhayon ◽

P. Hoet ◽

G. Van Maele-Fabry ◽

D. Lison

Keyword(s):

Occupational Exposure ◽

Critical Assessment ◽

Carcinogenic Potential ◽

Exposure Levels ◽

Occupational Settings

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The role of genotoxicity in asbestos-induced mesothelioma: an explanation for the differences in carcinogenic potential among fiber types

Inhalation Toxicology ◽

10.3109/08958378.2013.807321 ◽

2013 ◽

Vol 25 (9) ◽

pp. 553-567 ◽

Cited By ~ 12

Author(s):

Christy A. Barlow ◽

Laura Lievense ◽

Sherilyn Gross ◽

Christopher J. Ronk ◽

Dennis J. Paustenbach

Keyword(s):

Fiber Types ◽

Carcinogenic Potential

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Genotoxic and carcinogenic risks associated with the dietary consumption of repeatedly heated coconut oil

British Journal Of Nutrition ◽

10.1017/s0007114510002229 ◽

2010 ◽

Vol 104 (9) ◽

pp. 1343-1352 ◽

Cited By ~ 33

Author(s):

Smita Srivastava ◽

Madhulika Singh ◽

Jasmine George ◽

Kulpreet Bhui ◽

Anand Murari Saxena ◽

...

Keyword(s):

Edible Oils ◽

Health Hazard ◽

Coconut Oil ◽

Oral Intake ◽

Dependent Manner ◽

Repeated Heating ◽

Dietary Consumption ◽

Carcinogenic Potential ◽

Altered Hepatic Foci ◽

Polycyclic Aromatic

Repeated heating of vegetable oils at high temperatures during cooking is a very common cooking practice. Repeated heating of edible oils can generate a number of compounds, including polycyclic aromatic hydrocarbons (PAH), some of which have been reported to have carcinogenic potential. Consumption of these repeatedly heated oils can pose a serious health hazard. The objectives of the present study were to evaluate the genotoxic and carcinogenic risks associated with the consumption of repeatedly heated coconut oil (RCO), which is one of the commonly consumed cooking and frying medium. The PAH were analysed using HPLC in fresh CO, single-heated CO (SCO) and RCO. Results revealed the presence of certain PAH, known to possess carcinogenic potential, in RCO when compared with SCO. Oral intake of RCO in Wistar rats resulted in a significant induction of aberrant cells (P < 0·05) and micronuclei (P < 0·05) in a dose-dependent manner. Oxidative stress analysis showed a significant (P < 0·05) decrease in the levels of antioxidant enzymes such as superoxide dismutase and catalase with a concurrent increase in reactive oxygen species and lipid peroxidation in the liver. In addition, RCO given alone and along with diethylnitrosamine for 12 weeks induced altered hepatic foci as noticed by alteration in positive (γ-glutamyl transpeptidase and glutathione-S-transferase) and negative (adenosine triphosphatase, alkaline phosphatase and glucose-6-phosphatase) hepatospecific biomarkers. A significant decrease in the relative and absolute hepatic weight of RCO-supplemented rats was recorded (P < 0·05). In conclusion, dietary consumption of RCO can cause a genotoxic and preneoplastic change in the liver.

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Preliminary experimental findings using intraperitoneal assays to determine carcinogenic potential of man made mineral fibres: relevance to recent proposals for classification testing.

Occupational and Environmental Medicine ◽

10.1136/oem.52.10.700-a ◽

1995 ◽

Vol 52 (10) ◽

pp. 700-701 ◽

Cited By ~ 3

Author(s):

C Collier

Keyword(s):

Carcinogenic Potential ◽

Experimental Findings

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An International Appraisal of the Minimum Duration of Chronic Animal Toxicity Studies

Human & Experimental Toxicology ◽

10.1177/096032719201100302 ◽

1992 ◽

Vol 11 (3) ◽

pp. 155-162 ◽

Cited By ~ 14

Author(s):

Cynthia E. Lumley ◽

Christopher Parkinson ◽

Stuart R. Walker

Keyword(s):

Data Base ◽

Toxicity Tests ◽

Repeat Dose ◽

Carcinogenic Potential ◽

New Findings ◽

Regulatory Guidelines ◽

The Usa ◽

Adequate Data ◽

Pathology Data

1 There are international differences in regulatory guidelines for the appropriate duration of chronic, two species repeat-dose animal tests for new medicines intended for long-term use in man, ranging from 6 months in Europe to 12 months in Japan and the USA.1 2 An adequate data base is necessary to support any challenge to the scientific rationale behind regulatory guidelines with regard to the design, duration and relevance of toxicity tests of new medicines. 3 The Centre for Medicines Research has established an international toxicology data base which has been expanded to enable a comparison of data obtained within 6 months, with information from longer periods, for 154 studies. 4 Although new findings were revealed after 6 months for 9/75 cases for which pathology data are available at 6 and 12 months or longer, and 21/80 with data at 1 or 3 (but not 6 months) and 12 months or longer, in no instance did these influence the decision to drop or further develop the compounds in question. 5 These data suggest that a 6-month period of dosing is all that is routinely required for evaluating the chronic toxic (excluding carcinogenic) potential of a new chemical entity intended for therapeutic use.

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