Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PHENOLPHTHALEINS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1994

Comparative assessment of phenolphthalein and phenolphthalein glucuronide: is phenolphthalein glucuronide a better laxative?

BACKGROUND: Phenolphthalein is widely used as a safe and effective laxative. After oral administration, phenolphthalein is absorbed in the small bowel and is conjugated in the liver to phenolphthalein glucuronide which passes into the colon where it is deconjugated and the active compound, phenolphthalein, is released. Since phenolphthalein glucuronide does not undergo enterohepatic circulation it should theoretically have a more rapid onset of action and a lower threshold dose for laxation. The present study was designed to examine this issue. METHODS: Ten normal healthy subjects volunteered for the study. All subjects were administered placebo, phenolphthalein (at doses of 15, 30, 45, 60, 75 and 90 mg) or phenolphthalein glucuronide (at equivalent doses of 24, 48, 72, 96, 120 and 144 mg) in a random order. Stool weight, the frequency and consistency of stools, and the development of symptoms were recorded at 12-h intervals for 84 h. RESULTS: There was a significant increase in the mean stool weight obtained within the first 24 h of administration of a 30 mg dose of phenolphthalein and its glucuronide equivalent compared to the values obtained with placebo. A further increase in the dose did not improve the therapeutic response. There was no difference between phenolphthalein and phenolphthalein glucuronide with respect to the rapidity of action, the threshold dose, effectiveness of laxation, or the frequency of adverse effects. CONCLUSIONS: The therapeutic response and side effect profile of the different doses favoured 30 mg phenolphthalein as the optimum laxative dose. Although theoretically superior, phenolphthalein glucuronide was not found to be a more effective laxative compared to phenolphthalein in normal subjects.

Cathartics↗
PubMed1983

Comparison of phenolphthalein and phenolphthalein glucuronide on net water transport in rat ileum and colon.

Phenolphthalein is an odorless, tasteless compound, poorly soluble in water, but readily soluble in alcohol or ether. Although its laxative activity was discovered in 1902, the mechanism of action remains unclear. Phenolphthalein has been found to be an ineffective laxative in both jaundiced patients and in experimental animals with ligated common bile ducts. In contrast to the poor solubility of phenolphthalein, phenolphthalein glucuronide is highly water-soluble. In addition, phenolphthalein glucuronide is found in bile following oral phenolphthalein administration, suggesting an enterohepatic circulation. We compared the effect of phenolphthalein and phenolphthalein glucuronide on net water absorption of the ileum and colon of Sprague-Dawley rats using a single-pass perfusion technique. Perfusion of phenolphthalein (10 mg/dl in 154 mM NaCl with 0.5% ethanol and 0.1 g/l gum arabic) resulted in significantly reduced water absorption in both the ileum and colon (66% and 64%, respectively, P less than 0.05). In contrast, phenolphthalein glucuronide did not have a significant effect on net water flux compared to control perfusion in either the ileum or colon. In the ileum only 77 +/- 3% and colon 71 +/- 1.2% of the phenolphthalein infused was recovered, suggesting that much of the infused phenolphthalein was absorbed. In contrast there was no evidence of absorption of phenolphthalein glucuronide, as 98.9 +/- 1.2% was recovered from ileal and colon perfusions. Phenolphthalein glucuronide is not the active form of phenolphthalein, although it may be an effective laxative after deconjugation by colonic bacteria.

Animals↗
PubMed1992

Simultaneous determination of phenolphthalein and phenolphthalein glucuronide from dog serum, urine and bile by high-performance liquid chromatography.

A procedure is described to simultaneously quantitate phenolphthalein and its glucuronide metabolite from dog serum, urine and bile using high-performance liquid chromatography. The major advantages of this over pre-existing methods include direct analysis of the parent compound and glucuronide metabolite without enzymatic hydrolysis, increased sensitivity and the potential for automation of a large number of samples. Analytes were extracted from serum and urine using a combination of liquid- and solid-phase extraction methodology. Bile samples were analyzed directly after a twenty-fold dilution with mobile phase. The components plus internal standard were separated by reversed-phase high-performance liquid chromatography using step gradient elution and quantitated by the absorbance of ultraviolet light at 230 nm. Limits of detection from 1 ml of serum, 0.1 ml of urine and 0.05 ml of bile were 0.1, 0.5 and 10 microgram/ml for phenolphthalein and 0.1, 10 and 50 microgram/ml for phenolphthalein glucuronide, respectively.

Animals↗
PubMed1996

NTP Toxicology and Carcinogenesis Studies of Phenolphthalein (CAS No. 77-09-8) in F344/N Rats and B6C3F1 Mice (Feed Studies).

Phenolphthalein is used as a laboratory reagent and acid-base indicator and in over-the-counter laxative preparations. The National Cancer Institute nominated phenolphthalein for study because of its widespread use as a component in numerous laxative preparations and the lack of adequate testing for carcinogenicity in experimental animals. Male and female F344/N rats and B6C3F1 mice were exposed to phenolphthalein (98% to 99% pure) in feed for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, cultured Chinese hamster ovary cells, and mouse peripheral blood. 14-DAY STUDY IN RATS: Groups of five male and five female F344/N rats were given 0, 6,250, 12,500, 25,000, 50,000, or 100,000 ppm phenolphthalein in feed for 14 days. All rats survived to the end of the study. The final mean body weights of all exposed groups of rats were similar to those of the controls. No chemical-related gross or microscopic lesions were observed. 14-DAY STUDY IN MICE: Groups of five male and five female B6C3F1 mice were given 0, 6,250, 12,500, 25,000, 50,000, or 100,000 ppm phenolphthalein in feed for 14 days. All mice survived to the end of the study. The final mean body weights of all exposed groups of mice were similar to those of the controls. No chemical-related gross or microscopic lesions were observed. 13-WEEK STUDY IN RATS: Groups of 10 male and 9 or 10 female F344/N rats were given 0, 3,000, 6,000, 12,000, 25,000, or 50,000 ppm phenolphthalein (equivalent to average daily doses of approximately 200, 400, 800, 1,600, or 3,500 mg phenolphthalein/kg body weight to males and 200, 400, 800, 1,700, or 3,600 mg/kg to females) in feed for 13 weeks. Additional groups of 10 male and 10 female rats designated for clinical pathology evaluations were also given 0, 3,000, 6,000, 12,000, 25,000, or 50,000 ppm phenolphthalein in feed until day 21. All core study rats survived to the end of the study. The final mean body weight of the 50,000 ppm females and the body weight gains of the 25,000 and 50,000 ppm females were significantly lower than those of the controls. The final mean body weights and mean body weight gains of all other exposed groups were similar to those of the controls. There was no cathartic action or any other clinical finding attributed to exposure to phenolphthalein. The few differences in the hematology and clinical chemistry parameters were sporadic and were not considered to be chemical related. The percentage of motile sperm in the 12,000 ppm males was significantly greater than that in the controls, but no other significant differences in sperm morphology or vaginal cytology between exposed and control groups were observed. Absolute and relative liver weights of 25,000 and 50,000 ppm males were significantly greater than those of the controls. No chemical-related gross or microscopic lesions were observed. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were given 0, 3,000, 6,000, 12,000, 25,000, or 50,000 ppm phenolphthalein (equivalent to average daily doses of approximately 500, 1,000, 2,000, 4,100, or 9,000 mg phenolphthalein/kg body weight to males and 600, 1,200, 2,400, 5,000, or 10,500 mg/kg to females) in feed for 13 weeks. All mice survived until the end of the study. The final mean body weights and mean body weight gains of all exposed groups were similar to those of the controls. There was no cathartic action or any other clinical finding attributed to exposure to phenolphthalein. The absolute right cauda weight of the 12,000 ppm males and the absolute right epididymis weights of 12,000, 25,000, and 50,000 ppm males were significantly less than those of the controls. The percentages of abnormal sperm in 12,000, 25,000, and 50,000 ppm males were significantly greater than that in the control group, and the sperm concentrations in 12,000 and 50,000 ppm males were significantly less than that of the control group. The absolute and relative right testis weights of males exposed to 6,000 ppm or greater and the absolute right testis weight of 3,000 ppm mof 3,000 ppm males were significantly less than those of the controls. The incidences of hypoplasia of the bone marrow in males and females exposed to 12,000 ppm or greater were significantly greater than those in the controls. The incidences of hematopoiesis of the spleen in 25,000 and 50,000 ppm males were significantly greater than that in the controls. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female F344/N rats were given 0, 12,000, 25,000, or 50,000 ppm phenolphthalein (equivalent to average daily doses of approximately 500, 1,000, or 2,000 mg phenolphthalein/kg body weight to males and 500, 1,000, or 2,500 mg/kg to females) in feed for 2 years. Survival, Body Weights, and Clinical Findings: Survival of exposed males and females was similar to that of the controls. The mean body weights of exposed males were less than those of the controls through most of the second year of the study, and the mean body weights of exposed females were less than those of the controls from about week 16 until the end of the study. Clinical findings attributed to phenolphthalein exposure included thin appearance and ruffled fur in all exposed groups of males. Determinations of Total Phenolphthalein in Plasma: The mean plasma concentrations of total phenolphthalein (free and conjugated) after 2 years of exposure varied little with time of day. Plasma concentrations of total phenolphthalein were approximately the same between exposure groups and between males and females. Pathology Findings: The incidences of benign pheochromocytoma of the adrenal medulla in all exposed groups of males were significantly greater than those in the controls and occurred with a significant positive trend. The incidences of benign pheochromocytoma in 12,000 ppm females and of benign or malignant pheochromocytoma (combined) in 12,000 and 25,000 ppm females were significantly greater than those in the controls. The numbers of exposed males with bilateral benign pheochromocytomas exceeded the number of controls with these neoplasms. The incidences of malignant pheochromocytomas in exposed rats were similar to those in the controls. The incidences of focal hyperplasia of the adrenal medulla in the 12,000 and 50,000 ppm males were significantly greater than in the controls. The incidences of renal tubule adenoma in 50,000 ppm male rats and of renal tubule adenoma or carcinoma (combined) in 12,000 and 50,000 ppm male rats were significantly greater than those in the controls. Although the increased incidences were predominantly of renal tubule adenoma, four carcinomas were observed in exposed males (0 ppm, 0/50; 12,000 ppm, 1/50; 25,000 ppm, 1/50; 50,000 ppm, 2/50). The incidences of renal tubule neoplasms in exposed groups of females were similar to those in the controls. The findings from an extended evaluation (step section) of the kidneys of female rats were similar to those from the standard evaluation. The incidences of nephropathy in all exposed groups of females were significantly greater than in the controls, and the severity of nephropathy in all exposed groups of males and in 25,000 and 50,000 ppm females was significantly greater than in the controls. The incidences of diffuse hyperplasia of the parathyroid gland (0/41, 16/48, 14/49, 14/46), fibrous osteodystrophy of the bone (0/50, 17/50, 14/50, 12/50), and mineralization (0/50, 11/50, 5/50, 5/49) and degeneration (0/50, 11/50, 5/50, 4/49) of the glandular stomach in exposed groups of males were generally significantly greater than those in the controls. The incidences of hyperplasia of the thyroid gland C-cells (13/50, 3/50, 9/49, 4/49) in 12,000 and 50,000 ppm males were significantly less than in the controls. These lesions are commonly observed in male rats with more advanced nephropathy and are considered to be associated with a calcium/phosphorus imbalance created by compromised functional capacity of the kidney. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female B6C3F1 mice were given 0, 3,000, 6,000, or 12,000 ppm phenolphthalein (equivalent to average daily doses of approximately 300, 600, or 1,200 mg phenolphthalein/kg body weight to males and 400, 800, or 1,500 mg/kg to females) in feed for 2 years. Survival, Body Weights, and Clinical Findings: Survival of the 12,000 ppm females was significantly lower than that of the controls; survival of all other exposed groups of mice was similar to that of the controls. The mean body weights of 12,000 ppm males were slightly less than those of the controls beginning at week 93 of the study, and the mean body weights of the 3,000, 6,000, and 12,000 ppm females were less than those of the controls during most of the second year of the study. In exposed mice, there were no clinical findings related to phenolphthalein exposure. Determinations of Total Phenolphthalein in Plasma: The mean plasma concentrations of total phenolphthalein (free and conjugated) after 2 years of exposure varied little with time of day. Plasma concentrations of total phenolphthalein were approximately the same between exposure groups and between males and females. Pathology Findings: The incidences of histiocytic sarcoma in 6,000 and 12,000 ppm males and females were significantly greater than those in the controls and occurred with a significant positive trend. In this study, histiocytic sarcoma was consistently observed in the liver with several other sites (e.g., spleen, lung, bone marrow, and various lymph nodes) involved less frequently. The incidences of all types of malignant lymphoma and of lymphoma of thymic origin in all exposed groups of females were significantly greater than those in the controls and occurred with significant positive trends, while the incidences of all types of malignant lymphoma in all exposed groups of males were similar to that in the controls. The incidences of lymphoma of thymic origin were increased in exposed groups of males, but were significantly increased only in the 6,000 ppm group. The incidences of atypical hyperplasia of the thymus in 6,000 and 12,000 ppm males and in all exposed groups of females were significantly greater than those in the controls. The incidences of benign sex-cord stromal tumors of the ovary in all exposed groups of females were significantly greater than in the controls. The incidences of hyperplasia of the ovary in 3,000 and 12,000 ppm females were significantly greater than in the controls. The incidences of germinal epithelial degeneration of the testis in all exposed groups of males were significantly greater than that in the controls. There were increased incidences of myelofibrosis of the bone marrow in 12,000 ppm males (0 ppm, 3/50; 3,000 ppm, 8/50; 6,000 ppm, 8/50; 12,000 ppm, 19/49) and an increased severity but not incidence of this lesion in exposed females. There were also increased incidences of pigmentation of minimal to mild severity in the bone marrow of 6,000 and 12,000 ppm males (0/50, 2/50, 5/50, 16/49) and females (2/50, 3/50, 11/50, 11/50). Also, the incidences of hematopoietic cell proliferation in the red pulp of the spleen (10/50, 22/50, 28/50, 21/49) in all exposed groups of males were significantly greater than that in the controls, and the severity of this lesion increased with increasing exposure concentration. The incidences of hepatocellular adenoma in all exposed groups of males and females and of hepatocellular adenoma or carcinoma (combined) in 6,000 and 12,000 ppm males and all exposed groups of females were significantly less than those in the controls, and these lesions occurred with significant negative trends. Multiple hepatocellular adenomas were observed more frequently in the control groups than in the exposed groups. The incidences of clear cell and eosinophilic foci in all exposed groups of males and of mixed cell foci in 12,000 ppm males were significantly less than those in the controls. The incidences of eosinophilic foci in exposed groups of females were significantly less than that in the controls. GENETIC TOXICOLOGY: Phenolphthalein, tested in two laboratories, was not mutagenic in any of four strains of Salmonella typhimurium with or without S9 metabolic activation enzymes, and no induction of sister chromatid exchanges was observed in cultured Chinese hamster ovary cells treated with phenolphthalein with or without S9. However, significant increases in chromosomal aberrations were observed after treatment of cultured Chinese hamster ovary cells with phenolphthalein in the presence of S9, and the frequencies of micronucleated erythrocytes were increased in peripheral blood samples from male and female mice administered phenolphthalein in feed for 13 weeks. CONCLUSIONS: Under the conditions of these 2-year feed studies, there was clear evidence of carcinogenic activity of phenolphthalein in male F344/N rats based on markedly increased incidences of benign pheochromocytomas of the adrenal medulla and of renal tubule adenomas and adenomas or carcinomas (combined). There was some evidence of carcinogenic activity of phenolphthalein in female F344/N rats based on the increased incidences of benign pheochromocytomas of the adrenal medulla in the 12,000 ppm group and of benign or malignant pheochromocytomas (combined) in the 12,000 and 25,000 ppm groups. There was clear evidence of carcinogenic activity of phenolphthalein in male B6C3F1 mice based on increased incidences of histiocytic sarcomas and of malignant lymphomas of thymic origin. There was clear evidence of carcinogenic activity of phenolphthalein in female B6C3F1 mice based on increased incidences of histiocytic sarcomas, malignant lymphomas of all types, lymphomas of thymic origin, and benign sex-cord stromal tumors of the ovary. Exposure of rats to phenolphthalein in feed for 2 years resulted in increased incidences of focal hyperplasia of the adrenal medulla in males and in increased incidences and/or severity of nephropathy of the kidney in males and females. Exposure of mice to phenolphthalein in feed for 2 years resulted in increased incidences of atypical hyperplasia of the thymus in males and females, degeneration of the germinal epithelium of the testis in males, and ovarian hyperplasia in females. Exposure of mice to phenolphthalein in feed for 2 years resulted in decreased incidences of hepatocellular neoplasms and nonneoplastic lesions in males and females. Synonyms: 3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone; 3,3-bis( p-hydroxyphenyl)phthalide; a-p -hydroxyphenyl)-a- (4-oxo-2,5-cyclohexadien-1-ylidene)- o-toluic acid Trade names: Agoral®, Alophen®, Colax®, Correctol®, Dialose®, Doxidan®, Espotabs®, Evac-U-Gen®, Evac-U-Lax®, Ex-Lax®, Feen-A-Mint®, FemiLax®, Kondremul®, LaxCaps®, Lax-Pills®, Medilax®, Modane®, Phenolax®, Prulet®

Journal Article↗
PubMed2000

Induction of chromosome aberrations in vitro by phenolphthalein: mechanistic studies.

Phenolphthalein induces tumors in rodents but because it is negative in assays for mutation in Salmonella and in mammalian cells, for DNA adducts and for DNA strand breaks, its primary mechanism does not seem to be DNA damage. Chromosome aberration (Ab) induction by phenolphthalein in vitro is associated with marked cytotoxicity. At very high doses, phenolphthalein induces weak increases in micronuclei (MN) in mouse bone marrow; a larger response is seen with chronic treatment. All this suggests genotoxicity is a secondary effect that may not occur at lower doses. In heterozygous TSG-p53((R)) mice, phenolphthalein induces lymphomas and also MN, many with kinetochores (K), implying chromosome loss. Induction of aneuploidy would be compatible with the loss of the normal p53 gene seen in the lymphomas. Here we address some of the postulated mechanisms of genotoxicity in vitro, including metabolic activation, inhibition of thymidylate synthetase, cytotoxicity, oxidative stress, DNA damage and aneuploidy. We show clearly that phenolphthalein does not require metabolic activation by S9 to induce Abs. Inhibition of thymidylate synthetase is an unlikely mechanism, since thymidine did not prevent Ab induction by phenolphthalein. Phenolphthalein dramatically inhibited DNA synthesis, in common with many non-DNA reactive chemicals that induce Abs at cytotoxic doses. Phenolphthalein strongly enhances levels of intracellular oxygen radicals (ROS). The radical scavenger DMSO suppresses phenolphthalein-induced toxicity and Abs whereas H(2)O(2) potentiates them, suggesting a role for peroxidative activation. Phenolphthalein did not produce DNA strand breaks in rat hepatocytes or DNA adducts in Chinese hamster ovary (CHO) cells. All the evidence points to an indirect mechanism for Abs that is unlikely to operate at low doses of phenolphthalein. We also found that phenolphthalein induces mitotic abnormalities and MN with kinetochores in vitro. These are also enhanced by H(2)O(2) and suppressed by DMSO. Our findings suggest that induction of Abs in vitro is a high-dose effect in oxidatively stressed cells and may thus have a threshold. There may be more than one mechanism operating in vitro and in vivo, possibly indirect genotoxicity at high doses and also chromosome loss, both of which would likely have a threshold.

Animals↗
PubMed1997

Cell-transforming activity and genotoxicity of phenolphthalein in cultured Syrian hamster embryo cells.

Phenolphthalein is a cathartic agent widely used in non-prescription laxatives. For the simultaneous assessment of in vitro carcinogenicity and mutagenicity of phenolphthalein, the ability of this chemical to induce cell transformation and genetic effects was examined using the Syrian hamster embryo (SHE) cell model. Cell growth was reduced by treatment with phenolphthalein at 10-40 microM in a dose-related manner. Treatment with phenolphthalein for 48 hr induced a dose-dependent increase in morphological transformation of SHE cells. Over the dose range that resulted in cell transformation ( 10-40 microM), treatment of SHE cells with phenolphthalein induced gene mutations at the hprt locus but not at the Na+/K+ ATPase locus. A statistically significant level of chromosomal aberrations was elicited in SHE cells treated with phenolphthalein at the highest dose (40 microM). Meanwhile, neither numerical chromosomal changes nor DNA adduct formation, analyzed by the nuclease P1 enhancement version of 32P-post-labeling, were induced by treatment with phenolphthalein at any concentrations examined. We thus report cell-transforming activity and mutagenicity of phenolphthalein assessed with the same mammalian cells in culture. Our results provide evidence that phenolphthalein has cell-transforming and genotoxic activity in cultured mammalian cells. The mutagenic and clastogenic activities of phenolphthalein could be a causal mechanism for carcinogenicity in rodents.

Animals↗
PubMed1987

Estrogenic effects of phenolphthalein on human breast cancer cells in vitro.

There is a structural similarity between phenolphthalein and the triphenylethylenes which are known to interact with the estrogen receptor of human breast tissue. Phenolphthalein (10 microM) competed with estrogen for binding to MCF-7 human breast cancer cells in tissue culture and induced the synthesis of the progesterone receptor. The antiestrogen 4-hydroxytamoxifen blocked progesterone receptor induction both by estradiol and by phenolphthalein. Both estradiol (0.1 nM) and phenolphthalein (10 microM) stimulated cell growth as measured by DNA and protein assays. This growth stimulation was blocked by 4-hydroxytamoxifen. Phenolphthalein glucuronide, the major phenolphthalein metabolite, did not inhibit estrogen binding, induce progesterone receptor synthesis, or stimulate MCF-7 cell growth in culture. Yellow phenolphthalein, an impure phenolphthalein preparation used in nonprescription laxative preparations, had similar properties to pure phenolphthalein. Physicians should be aware of the weak estrogenic action of phenolphthalein, especially when recommending laxatives for breast cancer patients with confirmed liver and mesenteric metastases.

Binding, Competitive↗
PubMed1997

In vitro free radical metabolism of phenolphthalein by peroxidases.

Phenolphthalein, a widely used laxative, is the active ingredient in more than a dozen commercial nonprescription formulations. Fast-flow EPR studies of the reaction of phenolphthalein with horseradish peroxidase (HRP) and hydrogen peroxide permit the direct detection of two free radicals. One has EPR parameters characteristic of phenoxyl radicals. The other has a broad unresolved spectrum, possibly arising from free radical polymeric products of the initial phenoxyl radical. EPR spin-trapping studies of incubations of phenolphthalein with lactoperoxidase, reduced glutathione (GSH), and hydrogen peroxide with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) demonstrate stimulated production of DMPO/.SG compared with an identical incubation lacking phenolphthalein. In the absence of DMPO, measurements with a Clark-type oxygen electrode show that molecular oxygen is consumed by a sequence of reactions initiated by the glutathione thiyl radical. Enhanced production of DMPO superoxide radical adduct is also found in a system of phenolphthalein, NADH, and lactoperoxidase. In this system the phenolphthalein phenoxyl radical abstracts hydrogen from NADH to generate NAD., which is not spin trapped by DMPO, but reacts with molecular oxygen to produce the superoxide radical detected by EPR. In the absence of DMPO, the oxygen consumption is measured using the Clark-type electrode. Production of ascorbate radical anion is also enhanced in a system of phenolphthalein, ascorbic acid, hydrogen peroxide, and lactoperoxidase. Ascorbate inhibits oxygen consumption when phenolphthalein is metabolized in the presence of either glutathione or NADH by reducing radical intermediates to their parent molecules and forming the relatively stable ascorbate anion radical. The detection of enhanced free radical production in these three systems, a consequence of futile metabolism (or redox cycling), suggests that phenolphthalein may be a significant source of oxidative stress in physiological systems. Parallel EPR and oxygen consumption studies with phenolphthalein glucuronide give analogous results, but with lesser enhancement of free radical production.

Cathartics↗
PubMed1995

Phenolphthalein: induction of micronucleated erythrocytes in mice.

Phenolphthalein was tested for the induction of micronucleated erythrocytes in mice. Results of an initial investigation revealed significant, dose-related increases in micronucleated polychromatic erythrocytes (MN-PCE) and normochromatic erythrocytes (MN-NCE) in peripheral blood samples of male and female mice exposed to 0.6% to 5% phenolphthalein (approximately 1100 to 10,000 mg/kg/day) in feed for 90 days (Dietz et al., 1992). Results from a second long-term feed study with Swiss CD-1 mice confirmed this effect. However, administration of comparable doses of phenolphthalein by corn oil gavage on two consecutive days gave negative results in a mouse bone marrow micronucleus test. Subsequent tests were performed to clarify the conflicting results seen in the chronic exposure, dosed-feed, peripheral blood studies and the acute, corn oil gavage, bone marrow studies. Phenolphthalein was administered to male B6C3F1 mice in feed (3%) for 14 days. Peripheral blood samples taken at 4, 7, and 14 days all showed significant increases in micronucleated PCE; bone marrow samples taken on days 7 and 14 also were clearly positive for micronucleus induction. Therefore, comparable results were obtainable from both bone marrow and peripheral blood analyses. Because of the negative results in the two-exposure gavage test, additional tests were then designed to investigate the effects of bolus vs continuous dosing, feeding vs gavage administration, and corn oil vs feed as a carrier for phenolphthalein. Results of these tests indicated that the rate of exposure to phenolphthalein affects the frequency of induced MN-PCE and that micronucleated erythrocytes can be induced by phenolphthalein either by feeding or by corn oil gavage administration. In all the acute exposure studies, relatively high doses of phenolphthalein (2000-6000 mg/kg/day for at least 2 days) were required to induce micronuclei. The positive results obtained with phenolphthalein in vivo were consistent with the results of an in vitro chromosomal aberration test in Chinese hamster ovary cells, where dose-related increases in aberrations were noted only in cells treated in the presence of induced rat liver S9.

Animals↗
PubMed1992

Subchronic (13-week) toxicity studies of oral phenolphthalein in Fischer 344 rats and B6C3F1 mice.

Phenolphthalein is a cathartic agent that is widely used in over-the-counter laxatives. Thirteen-week toxicity studies of phenolphthalein were performed using F344/N rats and B6C3F1 mice. Rats and mice were fed ad libitum with a NIH 07 diet containing 0; 3000; 6000; 12,000; 25,000; or 50,000 ppm phenolphthalein. On a milligram per kilogram body weight basis, rats and mice fed 50,000 ppm phenolphthalein ingested more drug than would be expected during human laxative abuse. Phenolphthalein produced little evidence of toxicity in rats. There was slightly lower weight gain among the 25,000 and 50,000 ppm groups. Treated rats showed elevated relative kidney weights (males only) and elevated absolute and relative liver weights at 12,000-50,000 ppm phenolphthalein. Rat serum bile acids were depressed early (Days 5 and 6) by phenolphthalein treatment. Several treatment-related toxic effects, however, were identified in mice who received more phenolphthalein per unit body weight than rats. Although there were no effects on body weight gain, elevated liver weights were noted in female mice receiving 6000-50,000 ppm phenolphthalein. The primary treatment-related findings that occurred during the mouse studies involved the reproductive and hematopoietic systems. Reproductive changes including depressed testis and right epididymal weights and sperm density, an elevated production of abnormal sperm, and morphologic alterations in seminiferous tubules occurred at all levels of exposure (3000-50,000 ppm). Hematopoietic changes included bone marrow hypoplasia (12,000-50,000 ppm), increased splenic hematopoiesis (males only; 25,000 and 50,000 ppm), and an elevated incidence of micronucleated erythrocytes (6000-50,000 ppm).

Animals↗
PubMed1996

Phenolphthalein exposure causes multiple carcinogenic effects in experimental model systems.

Phenolphthalein (a triphenylmethane derivative) has been commonly used as a laxative for most of the twentieth century, but little is known about its long-term carcinogenic potential in experimental studies. In our studies, phenolphthalein administered continuously in the feed for 2 years to F344 rats at doses of 0, 12,500, 25,000, and 50,000 ppm and to C57BL/6 x CH3 F1 (hereafter called B6C3F1) mice at doses of 0, 3,000, 6,000, and 12,000 ppm caused multiple carcinogenic effects. Treatment-related neoplasms occurred in the kidney and adrenal medulla in male rats, adrenal medulla in female rats, hematopoietic system in male and female mice (histiocytic sarcomas and malignant lymphomas), and ovary of female mice. Phenolphthalein has been shown to have estrogenic and clastogenic properties. Previous studies of other estrogenic chemicals (e.g., zearalenone) in the F344 rat and B6C3F1 mouse have not shown the same spectrum of carcinogenic activity as that found with phenolphthalein, suggesting that phenolphthalein estrogenic activity alone is not responsible for the spectrum of tumors observed. It is more likely that the multiple biological properties of phenolphthalein, including its ability to form free radicals, its clastogenic activity, and its estrogenic activity, contributed to the carcinogenic effects observed. These studies show that phenolphthalein is a multisite/multispecies carcinogen. One of the sites for neoplasm that is of particular concern is the ovary, and epidemiology studies are under way to identify any potential effects of phenolphthalein exposure at this site in humans.

Animals↗
PubMed1998

Measurement of micronucleated erythrocytes and DNA damage during chronic ingestion of phenolphthalein in transgenic female mice heterozygous for the p53 gene.

Phenolphthalein, a common ingredient in nonprescription laxatives and a multisex, multispecies rodent carcinogen, was evaluated under chronic exposure conditions for genotoxicity in transgenic female mice heterozygous for the p53 gene (heterozygous TSG-p53 mice). Phenolphthalein was administered in the diet at 200, 375, 750, 3,000, and 12,000 ppm (corresponding to a time-weighted average of 37, 71, 146, 569, and 2,074 mg/kg/day, respectively) for 6 months (183 days). On days 39, 92, 137, and 183 of treatment, peripheral blood samples were collected and evaluated for the frequency of micronucleated polychromatic and normochromatic erythrocytes (MN-PCE and MN-NCE, respectively), the percentage of PCE (%PCE) among total erythrocytes, and the extent of DNA damage (single strand breaks, alkali labile sites, DNA crosslinking) in leukocytes. In addition, the extent of DNA damage was evaluated in liver parenchymal cells sampled from mice at the end of the 6-month treatment period. DNA damage was evaluated using the alkaline (pH > 13) Single Cell Gel (SCG) assay. In addition, using a modified SCG technique, the frequencies of leukocytes and liver parenchymal cells with extremely low molecular weight DNA (indicative of apoptosis and/or necrosis) were determined. At each sample time, phenolphthalein induced a highly significant, dose-dependent increase in the frequency of MN-PCE and MN-NCE and in %PCE. Maximal induction of MN-PCE and %PCE decreased with increasing treatment duration, most likely due to a treatment duration-dependent decrease in the relative amount of ingested phenolphthalein. A comparative analysis of the kinetochore status of MN in erythrocytes sampled from control mice and mice ingesting phenolphthalein at 12,000 ppm for 183 days indicates that the induced MN resulted predominantly but not exclusively from numerical chromosomal damage. The analysis for increased levels of DNA damage in blood leukocytes was inconclusive, with a small but statistically significant increase in DNA migration on days 39 and 137 but not on days 92 and 183. The extent of DNA migration in liver parenchymal cells sampled from mice at the end of treatment was not altered significantly. The frequencies of apoptotic and/or necrotic leukocytes and liver parenchymal cells were not increased among mice ingesting phenolphthalein. The lowest effective dose at which a significant genotoxic response (i.e., the induction of MN-NCE) was detected was 200 ppm, the lowest dose tested in this study. This dose in mice is comparable to doses (on a mg/m2 basis) experienced by humans.

Administration, Oral↗
PubMed1985

The disaccharide effect of sucrose feeding on glucuronide excretion and bile concentration of injected phenolphthalein in guinea pigs.

The hypothesis tested was that feeding guinea pigs sucrose produces a more rapid concentration in the bile and excretion in the feces and urine of substances catabolized by the liver than does feeding invert sugar (50:50 mixture of glucose and fructose). Fifty male guinea pigs of the Hartley strain were divided into two groups of 25 animals each and fed for 4 wk repelleted nonpurified diet with 20% of total energy provided by sucrose or invert sugar. At the end of 4 wk all 50 animals were injected i.p. with a dose of 15 mg/kg body weight of phenolphthalein. Phenolphthalein is excreted almost quantitatively in feces. After injection all guinea pigs were housed in metabolism cages. Urine and feces were recovered and analyzed for free glucuronic acid and glucuronide content by a modified naphthoresorcinol procedure over 24 h. Guinea pigs fed sucrose produced more urine than those fed invert sugar, although there was no difference in water intake. After 24 h 15 animals in each group were killed, and the bile was sampled from their gall bladders to determine its phenolphthalein content. The remaining 10 animals in each group were held three additional days when they were killed and their bile was sampled to determine its phenolphthalein content. All biliary phenolphthalein was in conjugated form. Guinea pigs fed sucrose had less free glucuronic acid in their feces than those fed invert sugar. Feeding sucrose resulted in a higher bile conjugated phenolphthalein content 4 d after injection than did feeding invert sugar.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Effect of phenolphthalein on monkey intestinal water and electrolyte transport.

To assess Na-K-ATPase inhibiton and prostaglandin synthesis stimulation as the mechanism of the secretory (cathartic) action of phenolphthalein in the primate, we investigated water and electrolyte transport and Na-K-ATPase levels in monkey intestine. Both jejunum and colon were studied with in vivo perfusion and in vitro Ussing chamber techniques. Water, Na, and Cl absorption was inhibited or secretion was induced by phenolphthalein (10(-3) M) in the jejunum and colon when the drug was present in the mucosal bathing (perfusion) solution. Serosal addition of phenolphthalein (10(-4) or 10(-3) M) induced Na and anion absorption in the jejunum but not in the colon. Phenolphthalein inhibited Na-K-ATPase activity in the test tube, but assays of intestine previously perfused or bathed in the drug showed no inhibiton. Indomethacin, in doses sufficient to inhibit prostaglandin synthesis in the intestine, inhibited the secretion induced by phenolphthalein in the jejunum but not in the colon. These inconsistencies cast doubt on the role of Na-K-ATPase inhibition or the role of prostaglandin synthesis stimulation in the mechanism of action of phenolphthalein.

Animals↗
PubMed2000

Phenolphthalein induces chromosome aberrations in human and Chinese hamster liver cells (CHEL) cultured in vitro.

Phenolphthalein is a nonprescription laxative agent that has been widely used during this century. Recent studies in animal models have shown that phenolphthalein has carcinogenic activity. In order to assess cytogenetic effects on human cells in vitro, we tested phenolphthalein in a chromosome aberration assay in human embryo cells derived from amniotic fluid. Our results show that phenolphthalein induces a significant increase in the frequency of chromosome aberrations in human cells. The lowest dose level at which the clastogenic effect is evident is 23.2 microg/ml. Similar positive results were obtained in a Chinese hamster liver cell line, which is metabolically competent to activate different classes of promutagens and procarcinogens into biologically active metabolites. Instead, parallel experiments in Chinese hamster ovary cells did not show any clastogenic effect due to phenolphthalein. These latter data suggested that phenolphthalein acts as a promutagen and must be metabolically activated to exert its clastogenic effect. Teratogenesis Carcinog. Mutagen. 20:209-217, 2000.

Amniotic Fluid↗
PubMedDate not supplied

Phenolphthalein induces thymic lymphomas accompanied by loss of the p53 wild type allele in heterozygous p53-deficient (+/-) mice.

Epidemiology studies have indicated that many human cancers are influenced by environmental factors. Genetically altered mouse model systems offer us the opportunity to study the interaction of chemicals with genetic predisposition to cancer. Using the heterozygous p53-deficient (+/-) mouse, an animal model carrying one wild type p53 gene and one p53 null allele, we studied the effects of phenolphthalein on tumor induction and p53 gene alterations. Earlier studies showed that phenolphthalein caused carcinogenic effects in Fisher 344 rats and B6C3F1 mice after a 2-yr dosing period (Dunnick and Hailey, Cancer Res. 56: 4922-4926, 1996). The p53 (+/-) mice received phenolphthalein in the feed at concentrations of 200, 375, 750, 3,000, or 12,000 ppm (approximately 43, 84, 174, 689, or 2,375 mg/kg body weight/day or 129, 252, 522, 2,867, or 7,128 mg/m2 body surface area/day) for up to 6 mo. A target organ cancer site that accumulated p53 protein in the B6C3F1 mouse (i.e., thymic lymphoma) was also a target site for cancer in the p53 (+/-) mouse. In the p53 (+/-) mouse, treatment-related atypical hyperplasia and malignant lymphoma of thymic origin were seen in the control and dosed groups at a combined incidence of 0, 5, 5, 25, 100, and 95%, respectively. Twenty-one of the thymic lymphomas were examined for p53 gene changes, and all showed loss of the p53 wild type allele. Chemical-induced ovarian tumors in the B6C3F1 mouse showed no evidence for p53 protein accumulation and did not occur in the p53 (+/-) mouse. The p53-deficient (+/-) mouse model responded to phenolphthalein treatment with a carcinogenic response in the thymus after only 4 mo of dosing. This carcinogenic response took 2 yr to develop in the conventional B6C3F1 mouse bioassay. The p53-deficient (+/-) mouse is an important model for identifying a carcinogenic response after short-term (< 6 mo) exposures. Our studies show that exposure to phenolphthalein combined with a genetic predisposition to cancer can potentiate the carcinogenic process and cause p53 gene alterations, a gene alteration found in many human cancers.

Animals↗