Teratological assessment of five oxidative hair dyes in the rat

The Effect of Resorcinol on Bovine Spermatozoa Parameters in Vitro

The goal of this study was to observe the effect of resorcinol on motility, viability and morphology of bovine spermatozoa. The semen was used from six randomly chosen breeding bulls. Ejaculate was diluted by different solutions of resorcinol in 1:40 ratio. Samples were divided into 7 groups with different concentrations of resorcinol (Control, RES1 - 4 mg/ml, RES2 - 2 mg/ml, RES3 - 1 mg/ml, RES4 - 0.5 mg/ml, RES5 - 0.25 mg/ml and RES6 - 0.125 mg/ml). Motility of spermatozoa was detected using CASA method at temperature of 37 °C in time periods 0, 1, 2, 3, 4 hours from the start of the experiment. Significant motility differences between all groups except control and RES6 with difference of 5.58 %, as well as between RES1 and RES2 groups with difference of 2.17 % were found. Progressive motility had the same significant differences. Spermatozoa viability (MTT test) decreased compared to control in all experimental groups during the entire duration of experiment. Observing morphologically changed spermatozoa, no significant changes were observed and a higher percentage of spermatozoa with separated flagellum in all experimental resorcinol groups compared to control were detected. Also, increased number of spermatozoa with broken flagellum, acrosomal changes and other morphological forms in the group with the highest concentration of resorcinol (RES1) were found. Results of our study clearly show negative effects on motility parameters of spermatozoa which depend on concentration, cultivation temperature and time period.

Development of a micellar electrokinetic capillary chromatography method for the determination of four naphthalenediols in cosmetics and a comparison with a HPLC method

A micellar electrokinetic capillary chromatography (MEKC) method with ultraviolet visible (UV) detection was used for the determination of 1,7-naphthalenediol, 2,3-naphthalenediol, 1,5-naphthalenediol, and 2,7-naphthalenediol in cosmetics. The current method for their determination in various cosmetics is high-performance liquid chromatography (HPLC). Separation conditions affecting the MEKC method were optimized as 20 mM Na₂ B₄ O₇ -50mM SDS, pH 9.8, with 22 kV applied voltage and UV detection at 230 nm. Under optimal conditions, electrophoretic analysis was completed in less than 6 min, with limit of detection (LOD) of 0.070-0.19 μg/mL and limit of quantitation (LOQ) of 0.23-0.63 μg/mL. A good linear relationship (r² > 0.99) was obtained at the range of 0.75-20 μg/mL. Recoveries for the four naphthalenediols in lotion, loose powder, and sun cream are between 91.2-107.2% with relative standard deviation (RSD) less than 4.04%. The method has been successfully applied to the determination of the four naphthalenediols in different kinds of cosmetics. A comparison with HPLC-UV method was also carried out according to the National Standards of the People's Republic of China. The results obtained by MEKC and HPLC methods are comparable, but the proposed MEKC method can help us obtain a much shorter detection time and low cost.

2: Final Report on the Safety Assessment of Retinyl Palmitate and Retinol

Retinol is the naturally occurring form of vitamin A; Retinyl Palmitate is the ester of Retinol and Palmitic Acid. In acute oral studies, Retinol was slightly toxic to mice, and Retinyl Palmitate was practically nontoxic in mice and rats. Large single doses can be lethal. It is recognized that Retinol is essential for reproduction; however, high intake of Retinol has produced adverse effects on several reproductive functions. Vitamin A was nonmutagenic in several in vitro tests. There is no evidence that vitamin A is carcinogenic. However, the vitamin has both enhanced and inhibited responses to viral or chemical carcinogens. Cosmetic products containing 0.1-1% Retinyl Palmitate were, at most, slightly irritating and nonsensitizing when tested on a total of 607 subjects. Results of cumulative irritation tests of two products containing 0.1% Retinyl Palmitate indicated that the products were nonirritating and non-sensitizing. On the basis of the available animal and clinical data presented in this report, it is concluded that Retinyl Palmitate and Retinol are safe as cosmetic ingredients in the present practices of use and concentration.

Knowledge and practices of, and attitudes towards, the use of hair dyes among females visiting a teaching hospital in Riyadh, Saudi Arabia

BACKGROUND AND OBJECTIVES

Use of hair dye is extremely common worldwide. However, our literature search failed to find studies concerning the knowledge and attitudes of the public with regard to hair dyes. We sought to explore the knowledge and practices of, and attitudes towards, the use of hair dye among females.

DESIGN AND SETTING

A cross-sectional survey conducted on females who attended various outpatient clinics at King Khalid University Hospital in Riyadh, Saudi Arabia, a tertiary referral hospital open to the general public.

PATIENTS AND METHODS

A self-administered questionnaire about the use of hair dyes was distributed randomly among females attending the outpatient clinics at a university hospital in 2008.

RESULTS

The response rate was 87.2%, with completion of 567 of the 650 distributed questionnaires. The mean (SD) age of respondents was 32.0 (10.2) years. Among respondents, 82.6% (464/562) had at some point dyed their hair. Furthermore, 69.3% (334/482) had dyed their hair in the past 12 months. The mean (SD) age of the participants when they first dyed their hair was 22.2 (7.1) years (range, 7-50). Of the participants, 76.8% (354/461) used permanent dyes, and about the same percentage of participants believed such dyes were the safest hair dye type. However, 52.4% (278/531) of the participants believed that hair dyes are harmful, and 36% (191/531) believed that hair dyes could cause cancer. Younger females tend to dye their hair less frequently (P<.001), whereas those with less education tend to dye their hair more frequently (P=.013).

CONCLUSION

Use of hair dye is very common among females. Because the practice starts at a very young age, we conclude that hair dyes are overused and misused. The public should be informed about the risks associated with excessive hair dye use.

Correlation of chemical structure with reproductive and developmental toxicity as it relates to the use of the threshold of toxicological concern

In the absence of toxicological data on a chemical, the threshold of toxicological concern (TTC) approach provides a system to estimate a conservative exposure below which there is a low probability of risk for adverse health effects. The original toxicology dataset underlying the TTC was based on NOELs from repeat dose studies. Subsequently there have been several efforts to assess whether or not these limits are also protective for reproductive/developmental effects. This work expands the database of chemicals with reproductive and developmental data, presents these data in a comprehensive and transparent format and groups the chemicals according to the TTC "Cramer Class" rules. Distributions of NOAELs from each of these classes were used to assess whether the previously proposed TTC values based on repeat dose data are protective for reproductive/developmental toxicity endpoints as well. The present analysis indicates that, for each Cramer Class, the reproductive and developmental endpoints would be protected at the corresponding general TTC tiers derived by Munro et al. (1996).

Two-Generation Reproductive Toxicity Study of Resorcinol Administered Via Drinking Water to Crl:CD(SD) Rats

The potential adverse effects of resorcinol, delivered via drinking water at 0, 120, 360, 1000, and 3000 mg/L (palatability limit), were assessed in a regulatory guideline compliant two-generation reproduction study in Crl:CD(SD) rats. Expanded end points of thyroid gland (TG) function were added because of clinical case reports indicating human TG toxicity. Average daily resorcinol intake (mg/kg) at the 3000 mg/L concentration was 233 in F0 and F1 males, whereas in females it was 304 (premating/gestation) and 660 (lactation). No resorcinol ingestion-related clinical signs of toxicity were observed. Furthermore, neither gross morphologic anomalies nor effects on reproductive function or thyroid hormone levels were detectable. Body weight reductions occurred in 3000 mg/L F0 and F1 animals and were more pronounced in males. However, there was no evidence of either cumulative toxicity in the second generation or of enhanced sensitivity to resorcinol in pregnant/lactating females. Water intake was lower in 3000 mg/L rats of both generations and intermittently, to a lesser extent, at 1000 mg/L; however, concurrent feed intake and utilization were unaffected. Decreased TG follicular colloid content (conventional histopathology; confirmed by quantitative stereomicroscopy) in the 3000 mg/L F0 males was attributed to resorcinol but not considered adverse. The 3000 mg/L intake level appeared to have caused an adaptive thyroid response to a new homeostatic level with no adverse physiological consequences in either males (the more susceptible gender) or females. There were no differences in TG histology in F0 rats of either sex at 1000 mg/L. Thus, resorcinol intake at maximum palatability via a route and mode relevant to potential human exposures via contaminated drinking water at presently unknown environmental concentrations caused no detectable adverse effects on any reproduction or TG end points. The 3000 mg/L resorcinol exposure level was the no-observed-adverse-effect level (NOAEL) for parental systemic and offspring toxicity, while 1000 mg/L was the no-observed-effect level (NOEL).

Final report on the safety assessment of HC Yellow No. 5

HC Yellow No. 5 is a direct hair dye. Hair dyes containing HC Yellow No. 5, as "coal tar" hair dye products, are exempt from the principal adulteration provision and from the color additive provision of the Federal Food, Drug, and Cosmetic Act of 1938 when the label bears a caution statement and "patch test" instructions for determining whether the product causes skin irritation. Preliminary testing on or by individuals should be done using an open patch test that is evaluated at 48 h after application of the test material. Users, therefore, would be able to determine their individual reactions to hair dye products containing HC Yellow No. 5. Absorption of HC Yellow No. 5 is minimal through skin (< 0.2%). The oral LD(50) for rats is 555.56 mg/kg. No significant toxic effects were observed after chronic oral exposure of HD Yellow No. 5 to dogs. Mild dermal irritation, but no dermal sensitization or ocular irritation was observed in laboratory animals. Results of fertility and reproductive performance, teratology, and developmental studies were negative. HC Yellow No. 5 was found to be nonmutagenic and noncytotoxic in standard laboratory assays. A current review of the hair dye epidemiology literature identified that use of direct hair dyes, although not the focus in all investigations, appears to have little evidence of an association with cancer or other adverse events. Based on the available safety test data on HC Yellow No. 5, the Panel determined that this ingredient likely would not have carcinogenic potential as used in hair dyes. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that HC Yellow No. 5 is safe as a hair dye ingredient in the practices of use and concentration as described in this safety assessment.

The Oral Toxicity of Resorcinol During Pregnancy: A Case Report

Resorcinol (1,3 benzenediol; m-dihydroxybenzene: resorcin) is a pharmaceutical agent used topically in dermatological treatments such as acne and related skin conditions. It could also be used in combination with the other acne treatment agents such as sulphur. It could be very hazardous if taken orally and there are limited reports on its toxic effects in human. The present work aimed to report a resorcinol poisoning case in which resorcinol was taken accidentally by a woman at 30 weeks of pregnancy. The major clinical findings were unconsciousness, drowsiness, and respiratory failure that required mechanical ventilation along with tonic-clonic seizures and hypothermia. In addition, the laboratory findings were leucocytosis, high bilirubin levels, severe metabolic acidosis, and green-colored urine. The fetus was considered dead 24 h after delivery; however, mother's prognosis was well with supportive management. It could be concluded that the basic approach to the patient with resorcinol poisoning should include the initial stabilization of immediate life-threatening problems and elimination of the toxin. This is the first report on resorcinol poisoning in pregnant women, indicating its major clinical and laboratory findings.

Toxicology review and risk assessment of resorcinol: thyroid effects

Resorcinol administered at high doses to rodents can disrupt thyroid hormone synthesis and can produce goitrogenic effects. These effects were not seen in a 2-year bioassay at doses of up to 520 mg/kg/day. There are species-specific differences in synthesis, binding, and transport of thyroid hormone that complicate interpretation of goitrogenesis in rodents. Clinical case reports from patients undergoing resorcinol therapy for dermatological indications reveal thyroid side effects when copious amounts of resorcinol-containing ointments are applied to integrity-compromised skin for months to years. Effect levels were greater than 34 mg/kg/day. Occupational epidemiology studies provide no evidence that exposure to resorcinol at levels greater than found in the general environment causes thyroid dysfunction. Studies investigating the relationship between endemic goiter and exposure to "phenolics," including resorcinol, in drinking water do not fulfill accepted scientific criteria for establishing resorcinol as a cause of thyroid disease. Those reports neither quantify exposure levels nor demonstrate dose-response relationships or rule out confounding by the multiple other chemicals present in water supplies, by bacterial contamination of water, or by nutritional factors. A risk assessment comparing potential worst-case exposures to resorcinol through its use in dermatological preparations supports the conclusion that under real-world conditions, human exposures to resorcinol are not expected to cause adverse effects on thyroid function.

Maternal occupational exposure to chemical substances and the risk of infants small-for-gestational-age

BACKGROUND

The association between maternal occupational exposure to specific chemical substances (organic solvents, carbon tetrachloride, herbicides, chlorophenols, polychlorinated biphenyls, aromatic amines, lead and lead compounds, mercury and mercury compounds) and birth of small-for-gestational-age (SGA) infants was evaluated using data from a prospective cohort study of 3,946 pregnant women in West Germany from 1987 to 1988.

METHODS

Occupational, medical, and psychosocial information was gathered through a questionnaire from pregnant women who were recruited between 15 and 28 gestational weeks. Exposure to chemical substances at the current workplace was assessed by a job-exposure matrix constructed by Pannett in 1985 and weighted for the number of working hours per week. Women not working at the time of the interview, women with multiple births, and women with stillbirths were excluded from analysis. Data were analyzed using dichotomous and polytomous logistic regression to control for age, smoking status, alcohol consumption, body mass index, and number of former births.

RESULTS

The results of the dichotomous logistic regression analysis suggest that leather work might be associated with the birth of infants small-for-gestational-age through exposure to chlorophenols (P = 0.02) and aromatic amines (P = 0.05). In the polytomous logistic regression analysis, only the association between exposure to mercury and growth retardation reached statistical significance (P = 0.02); however, the power of the study is limited. Further adjustment for income, shift work, and heavy physical work had no substantial effect on the results.

CONCLUSIONS

These findings suggest that maternal exposure to specific chemicals at work may be a risk factor for the birth of SGA infants.

Prenatal adverse effects of various drugs and chemicals. A review of substances of frequent concern to mothers in the community

Using the number of calls to the Canadian Motherisk Program as an indicator of the drugs and chemicals frequently of concern to mothers during pregnancy, the risks to the fetus of exposure to these compounds have been reviewed. The drugs which were of concern, and have been proven to be teratogenic, included alcohol, alkylating and antimetabolite agents, stilboestrol, disulfiram, heparin, lithium carbonate, phenytoin, tretinoin (retinoic acid), troxidone and valproic acid. For other compounds studied, there was either no data in the literature or no clear evidence of teratogenicity. The combination of doxylamine and pyridoxine, for example, has been associated with limb reduction defects in isolated case reports: cohort and case-control studies have failed to show a higher-than-baseline risk of malformations. In some cases of exposure to compounds with no known teratogenic potential, other adverse effects to the fetus are possible, and these effects are discussed in detail. In conclusion, when advising a pregnant woman about the potential teratogenic effect of a particular drug or chemical exposure, the health professional should also discuss other factors such as age, obstetric and medical history and the history of other exposures (including alcohol and smoking). In every pregnancy there is a 1 to 5% risk of mayor malformations, and even if the exposure does not appear to increase the teratogenic risk, such a risk still exists.

A tier system for developmental toxicity evaluations based on considerations of exposure and effect relationships

The backlog of untested chemicals and the rate at which new substances enter the marketplace exceed our capacity for developmental effects testing by standard in vivo methods. However, conservative use of two observations in a manner consistent with present day understanding of abnormal developmental biology can more accurately focus attention and resources on those agents in greatest need of complex testing for effects on in utero development. These two observations are 1) most chemicals are no more toxic to embryonic development than they are to adult homeostasis and 2) most human exposure to chemicals is de minimus, i.e., so small that it is inconsequential. Recently devised in vitro assays to quantitatively rank chemicals according to their developmental hazard index, when used in conjunction with more conventional in vivo methods and appropriate considerations of exposure, permit evaluation of a significantly larger number of chemicals than is currently achieved. The methods described apply a tier approach to establish testing priorities that markedly reduce the time, cost, and number of laboratory animals needed for evaluation of developmental toxicity.