Comparison of the efficacy of gossypol acetate enantiomers in rats with uterine leiomyoma.

Gossypol acetate (GA), as the product of racemic gossypol and acetic acid conjugated by hydrogen bond, is hydrolyzed into gossypol to exert its effect on treating uterine leiomyoma (UL), which has been listed in China. But hypokalemia and mild changes of liver function limit its clinical application. It had been reported that the biological activities of gossypol optical isomers were different. In this study, we aimed to clarify whether there were differences in the efficacy of gossypol enantiomers and whether a single gossypol optical isomer could alleviate adverse reactions in the treatment of UL. The results indicated that (-)-GA and (+)-GA had significant therapeutic effect on rats with UL. Interestingly, (-)-GA could better significantly ameliorate the pathological structure, inhibit the secretion of estrogen, and downregulate the expression of estrogen receptor-alpha (ER-α) and progesterone receptor (PR) than (+)-GA. Additionally, (-)-GA could better evidently decrease the symptoms of abnormally elevated inflammatory factors caused by UL. In contrast, (-)-GA and (+)-GA had certain effects on potassium ion concentration in serum, liver and kidney function, and the effects of (+)-GA on liver function were more obvious than (-)-GA. These findings will be of great significance to the drug development of gossypol optical isomers.

Gossypol exposure induces mitochondrial dysfunction and oxidative stress during mouse oocyte in vitro maturation.

Gossypol is a yellow natural polyphenolic compound extracted from the seeds, leaves, stems, and flower buds of the cotton plant. Several studies have shown that exposure to gossypol impacts reproductive health in both humans and animals. However, whether gossypol exposure would influence oocyte quality has not yet been determined. Here, we studied the effects of gossypol on the meiotic maturation of mouse oocytes in vitro. The results revealed that gossypol exposure did not affect germinal vesicle breakdown (GVBD) but significantly reduced polar body extrusion (PBE) rates. Moreover, we observed meiotic spindle organization and chromosome alignment were entirely disturbed after gossypol exposure. Further, gossypol exposure also caused mitochondrial dysfunction and abruptly decreased the levels of cellular ATP, and diminished the mitochondrial membrane potential (MMP). Accordingly, gossypol-induced oxidative stress was confirmed through an increased level of reactive oxygen species (ROS). Early apoptosis incidence also increased as identified by positive Annexin-V signaling. Collectively, the above findings provide evidence that gossypol exposure impaired oocyte meiotic maturation, disturbed spindle structure and chromosome dynamics, disrupted mitochondrial function, induced oxidative stress, and triggered early apoptosis. These findings emphasize gossypol's adverse effects on oocyte maturation and thus on female fertility.

A randomized, double-blind, placebo-controlled study of B-cell lymphoma 2 homology 3 mimetic gossypol combined with docetaxel and cisplatin for advanced non-small cell lung cancer with high expression of apurinic/apyrimidinic endonuclease 1.

Background Overexpression of apurinic/apyrimidinic endonuclease 1 (APE1) is an important cause of poor chemotherapeutic efficacy in advanced non-small cell lung cancer (NSCLC) patients. Gossypol, a new inhibitor of APE1, in combination with docetaxel and cisplatin is believed to improve the efficacy of chemotherapy for advanced NSCLC with high APE1 expression. Methods Sixty-two patients were randomly assigned to two groups. Thirty-one patients in the experimental group received 75 mg/m2 docetaxel and 75 mg/m2 cisplatin on day 1 with gossypol administered at 20 mg once daily on days 1 to 14 every 21 days. The control group received placebo with the same docetaxel and cisplatin regimen. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), response rate, and toxicity. Results There were no significant differences in PFS and OS between the experimental group and the control group. The median PFS (mPFS) in the experimental and control groups was 7.43 and 4.9 months, respectively (HR = 0.54; p = 0.06), and the median OS (mOS) was 18.37 and 14.7 months, respectively (HR = 0.68; p = 0.27). No significant differences in response rate and serious adverse events were found between the groups. Conclusion The experimental group had a better mPFS and mOS than did the control group, though no significant difference was observed. Because the regimen of gossypol combined with docetaxel and cisplatin was well tolerated, future studies with larger sample sizes should be performed.

Regulation of Cell Viability and Anti-inflammatory Tristetraprolin Family Gene Expression in Mouse Macrophages by Cottonseed Extracts.

Bioactive plant extracts have been used for the prevention and treatment of various diseases. One of the major classes of bioactive compounds is plant polyphenols. Cottonseed ethanol extracts were determined by HPLC-MS analysis to be essentially free of toxic gossypol. The objective of this study was to investigate the effect of cottonseed ethanol extracts on the cytotoxicity and regulation of anti-inflammatory tristrataprolin (TTP) family gene expression in mouse cells. MTT, qPCR and immunoblotting assays tested the effects of cottonseed extracts in mouse RAW264.7 macrophages and 3T3-L1 adipocytes. No cytotoxicity effect was observed in macrophages treated with extracts from the coat or kernel of glanded and glandless cottonseed. Similarly, the viability of mouse adipocytes was not affected by cottonseed extracts. In contrast, gossypol and lipopolysaccharides were toxic to macrophages but not adipocytes under high concentration or long time treatment. Cottonseed extracts exhibited modest effect on TTP family gene expression in macrophages but glandless cottonseed coat extract significantly increased TTP mRNA and protein levels with a magnitude similar to cinnamon and green tea polyphenol extract and insulin. These results demonstrated that cottonseed extracts are harmless towards the mouse cells and that glandless cottonseed coat extract stimulates TTP gene expression. We propose that glandless cottonseed is a safe source of plant polyphenols with anti-inflammatory property.

A phase II study of the orally administered negative enantiomer of gossypol (AT-101), a BH3 mimetic, in patients with advanced adrenal cortical carcinoma.

Background Adrenal cortical carcinoma (ACC) is a rare cancer with treatment options of limited efficacy, and poor prognosis if metastatic. AT-101 is a more potent inhibitor of B cell lymphoma 2 family apoptosis-related proteins than its racemic form, gossypol, which showed preliminary clinical activity in ACC. We thus evaluated the efficacy of AT-101 in patients with advanced ACC. Methods Patients with histologically confirmed metastatic, recurrent, or primarily unresectable ACC were treated with AT-101 (20 mg/day orally, 21 days out of 28-day cycles) until disease progression and/or prohibitive toxicity. The primary endpoint was objective response rate, wherein a Response Evaluation Criteria In Solid Tumors (RECIST) partial response rate of 25% would be considered promising and 10% not, with a Type I error of 10% and 90% power. In a 2-stage design, 2 responses were required of the first 21 assessable subjects to warrant complete accrual of 44 patients. Secondary endpoints included safety, progression-free survival and overall survival. Results This study accrued 29 patients between 2009 and 2011; median number of cycles was 2. Seven percent experienced grade 4 toxicity including cardiac troponin elevations and hypokalemia. None of the first 21 patients attained RECIST partial response; accordingly, study therapy was deemed ineffective and the trial was permanently closed. Conclusions AT-101 had no meaningful clinical activity in this study in patients with advanced ACC, but demonstrated feasibility of prospective therapeutic clinical trials in this rare cancer.

A phase II trial of the BCL-2 homolog domain 3 mimetic AT-101 in combination with docetaxel for recurrent, locally advanced, or metastatic head and neck cancer.

BACKGROUND: AT-101 is a BCL-2 Homolog domain 3 mimetic previously demonstrated to have tumoricidal effects in advanced solid organ malignancies. Given the evidence of activity in xenograft models, treatment with AT-101 in combination with docetaxel is a therapeutic doublet of interest in metastatic head and neck squamous cell carcinoma. PATIENTS AND METHODS: Patients included in this trial had unresectable, recurrent, or distantly metastatic head and neck squamous cell carcinoma (R/M HNSCC) not amenable to curative radiation or surgery. This was an open label randomized, phase II trial in which patients were administered AT-101 in addition to docetaxel. The three treatment arms were docetaxel, docetaxel plus pulse dose AT-101, and docetaxel plus metronomic dose AT-101. The primary endpoint of this trial was overall response rate. RESULTS: Thirty-five patients were registered and 32 were evaluable for treatment response. Doublet therapy with AT-101 and docetaxel was well tolerated with only 2 patients discontinuing therapy due to treatment related toxicities. The overall response rate was 11 % (4 partial responses) with a clinical benefit rate of 74 %. Median progression free survival was 4.3 months (range: 0.7-13.7) and overall survival was 5.5 months (range: 0.4-24). No significant differences were noted between dosing strategies. CONCLUSION: Although met with a favorable toxicity profile, the addition of AT-101 to docetaxel in R/M HNSCC does not appear to demonstrate evidence of efficacy.

Mechanisms involved in reproductive damage caused by gossypol in rats and protective effects of vitamin E

BACKGROUND: Gossypol is a chemical present in the seeds of cotton plants (Gossypium sp.) that reduces fertility in farm animals. Vitamin E is an antioxidant and may help to protect cells and tissues against the deleterious effects of free radicals. The aim of this study was to evaluate the mechanisms of reproductive toxicity of gossypol in rats and the protective effects of vitamin E. Forty Wistar rats were used, divided into four experimental groups (n = 10): DMSO/ saline + corn oil; DMSO/saline + vitamin E; gossypol + corn oil; and gossypol + vitamin E. RESULTS: Fertility was significantly reduced in male rats treated with gossypol in that a significant decrease in epididy-mal sperm count was observed (P < 0.05) and the number of offspring was significantly reduced in females mated with them (P < 0.05). This dysfunction was prevented by vitamin E. Gossypol caused a significant increase in the activity of the enzymes glutathione peroxidase (P < 0.01) and glutathione reductase (P < 0.01), but vitamin E did not reduce the enzyme activities (P > 0.05). The levels of reduced glutathione and pyridine nucleotides in testis homogen-ate were significantly reduced by gossypol (P < 0.05 and P < 0.01, respectively) and this reduction was accompanied by increased levels of oxidized glutathione (P < 0.05). Vitamin E showed a preventive effect on the changes in the levels of these substances. Gossypol significantly increased the levels of malondialdehyde (P < 0.01), a lipid peroxida-tion indicator, whereas treatment with vitamin E inhibited the action of the gossypol. Vitamin E prevented a decrease in mitochondrial ATP induced by gossypol (P < 0.05). CONCLUSIONS: This study suggests that the reproductive dysfunction caused by gossypol may be related to oxidative stress and mitochondrial bioenergetic damage and that treatment with vitamin E can prevent the infertility caused by the toxin.

Gossypol promotes degeneration of ovarian follicles in rats.

The present study aimed to determine if gossypol interferes with ovarian follicles in rats. Twenty-four female Wistar rats were assigned to two equal groups: one control group and the other dosed with gossypol (25 mg/kg/day, subcutaneously) for 15 days. Ovarian follicles were histologically classified according to the stage of development and as normal or atretic. Gossypol treatment reduced the length of estrous with an increase in the duration of the diestrus phase. This compound was responsible for reduced serum levels of T4 and progesterone. Treatment with gossypol was responsible for a significant reduction in the number of normal ovarian follicles and a significant increase in the number of atretic follicles, both in all stages of development. Thus, treatment of rats with gossypol was responsible for reduction in the number of viable follicles and changes in hormone levels that resulted in interference of the estrous cycle.

A phase I study of AT-101 with cisplatin and etoposide in patients with advanced solid tumors with an expanded cohort in extensive-stage small cell lung cancer.

BACKGROUND: A phase I, dose-escalation study of AT-101 with cisplatin and etoposide was conducted to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), safety and pharmacokinetics in patients with advanced solid tumors, with an expanded cohort in patients with extensive-stage small cell lung cancer (ES-SCLC) to assess preliminary activity. METHODS: In the dose escalation portion, increasing doses of AT-101 were administered orally BID on days 1-3 along with cisplatin on day 1 and etoposide on days 1-3 of a 21 day cycle. At the RP2D, an additional 7 patients with untreated ES-SCLC were enrolled. RESULTS: Twenty patients were enrolled in the dose-escalation cohort, and 7 patients with ES-SCLC were enrolled in the expanded cohort. The MTD/RP2D was established at AT-101 40 mg BID days 1-3 with cisplatin 60 mg/m2 and etoposide 120 mg/m2 on day 1 of a 21 day cycle with pegfilgrastim support. Two DLTs of neutropenic fever were seen at dose level 1. After the addition of pegfilgrastim, no additional DLTs were observed. Grade 3/4 treatment-related toxicities included: diarrhea, increased AST, neutropenia, hypophosphatemia, hyponatremia, myocardial infarction and pulmonary embolism. No apparent PK interactions were observed between the agents. Preliminary activity was observed with PRs in patients with ES-SCLC, high-grade neuroendocrine tumor, esophageal cancer and NSCLC. CONCLUSIONS: AT-101 with cisplatin and etoposide is well tolerated with growth factor support. Anti-tumor activity was observed in a variety of cancers including ES-SCLC, supporting further investigation with BH-3 mimetics in combination with standard chemotherapy for ES-SCLC.

Mecanismos da intoxicação do fígado de rato causada pelo gossipol / Mechanisms of the intoxication of rat liver caused by gossypol

O fígado desempenha uma função central no metabolismo devido à sua interposição entre o trato digestivo e a circulação geral do organismo. Ele é também o principal órgão envolvido na biotransformação de substâncias exógenas (xenobióticos), com capacidade de converter compostos hidrofóbicos em hidrossolúveis, mais facilmente eliminados pelo organismo. O gossipol é uma substância fenólica tóxica presente na semente de algodão (Gossypium sp). Com o objetivo de estudar os mecanismos envolvidos na hepatotoxicidade do gossipol avaliou-se os seus efeitos no sistema antioxidante do fígado de ratos no que diz respeito ao estresse oxidativo e aspectos histopatológicos. Foram utilizados ratos machos da linhagem Wistar, separados em dois grupos, sendo que um recebeu óleo de canola (veículo, grupo Controle) e o outro recebeu gossipol na dosagem de 40 mg/kg de peso vivo do animal por 15 dias (grupo Tratado). O tratamento com gossipol promoveu alterações na atividade sérica das enzimas marcadoras de dano hepático e um significativo estresse oxidativo caracterizado pela diminuição nos níveis da glutationa reduzida (GSH) e consequente aumento da glutationa oxidada (GSSG), incluindo, ainda, danos à membrana plasmática e de organelas demonstrados pela peroxidação lipídica. O resultado da avaliação histopatológica demonstrou degeneração dos hepatócitos.

The liver plays a central role in metabolism due to its interposition between the digestive tract and the general circulation of the organism. It is also the main organ involved in biotransformation of exogenous substances (xenobiotics), with ability to convert hydrophobic compounds in water-soluble, more easily eliminated by the body. Gossypol is a toxic phenolic substance present in cotton seed (Gossypium sp.). Aiming to study the mechanisms involved in the hepatotoxicity of gossypol we evaluate its effects on the antioxidant system of rat liver performing an experiment that investigated the oxidative stress and the histopathological alterations. In this study, we used Wistar rats, divided into two groups, one that received canola oil (vehicle, Control group) and another that received gossypol at a dose of 40mg/kg body weight of the animal for 15 days (Treated group). The treatment with gossypol caused alterations in the activity of seric enzymes that indicate hepatic injury and a significant oxidative stress characterized by a decrease of reduced glutathione (GSH) levels and a consequent increase in oxidized glutathione (GSSG), including further damage to the plasma membrane and organelles showed by lipid peroxidation. The result of histopathological evaluation showed degeneration of the hepatocytes.

Suppression of LPS-induced inflammatory responses by gossypol in RAW 264.7 cells and mouse models.

Gossypol, a yellowish polyphenolic compound originally from cotton plant, has been known to exert a potential for anti-cancer, anti-inflammatory and other important therapeutic activities. The purpose of this investigation was to determine the protection of gossypol on inflammation in Lipopolysaccharide (LPS) stimulated RAW 264.7 cells and LPS induced in vivo lung injury model. The effects of gossypol on pro-inflammatory cytokines and signaling pathways were evaluated by enzyme-linked immunosorbent assay and Western blot. The results showed that gossypol significantly inhibited the production of LPS-induced TNF-α, IL-6 and IL-1ß both in vitro and vivo. Furthermore, gossypol blocked the phosphorylation of IκBα protein, p65, p38, c-Junterminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in LPS stimulated RAW 264.7 cells. From the in vivo study, it was observed that gossypol attenuated lung histopathologic changes in mouse models. The present data suggest that gossypol suppresses the inflammation in vitro and vivo, and may be a potential therapeutic candidate for the treatment of inflammatory disorders.

A combined regimen of gossypol plus methyltestosterone and ethinylestradiol as a contraceptive induces germ cell apoptosis and expression of its related genes in rats.

Attempts to develop gossypol and steroidal hormones alone as a male contraceptive have been tested for many years; however, both caused undesirable side effects that have prevented their acceptance. In this study, we formulated a regimen of combined gossypol at a low dose of 12 mg/kg or a high dose of 50 mg/kg plus methyltestosterone 20 mg/kg and ethinylestradiol 100 g/kg daily (12 mg G+H and 50 mg G+H) administered for 6 weeks in adult rats. The possible roles of germ cell apoptosis and related genes expression were studied by techniques of TdT-mediated dUTP nick end-labeling (TUNEL), agarose gel electrophoresis of low-molecular-weight DNA, in situ hybridization and reverse transcription-polymerase chain reaction detection. Results showed that germ cell apoptosis and related genes expression were significantly induced after combined drug administration. The apoptosis index increased 3.86- and 9.65-fold in the 12-mg and 50-mg G+H-treated groups, respectively, as compared to the control group. DNA ladder formation on the agarose gel further validated the findings of TUNEL-stained apoptotic cells. The apoptosis-related genes fas mRNA expression levels increased 0.44- and 1.39-fold, bax mRNA 0.74- and 2.56-fold, caspase-3 mRNA 0.60- and 1.29-fold, and caspase-9 mRNA 2.50- and 4.08-fold, respectively, in the 12-mg and 50-mg G+H-treated groups vs. the control group. These results indicated that our drug regimen applied as a contraceptive could induce rat germ cell apoptosis. The apoptotic process involved fas system, bax and caspase family genes and the apoptotic extent and cell types were gossypol dose-dependent.

Effects of gossypol from cottonseed meal and dietary vitamin E on the reproductive characteristics of superovulated beef heifers.

Superovulated Hereford-Angus crossbred heifers (average 397 kg BW) were used to test the effect of feeding cottonseed meal (gossypol) and vitamin E on embryo quality and ovarian characteristics. Twenty-four heifers were assigned randomly to four treatments with six heifers per treatment. Treatments were the following dietary supplements: 1) SBM (soybean meal + 30 IU vitamin E/kg of diet DM); 2) SBM+E (soybean meal + 4,000 IU vitamin E x animal(-1) x d(-1)); 3) CSM (cottonseed meal + 30 IU vitamin E/kg of diet DM); and 4) CSM+E (cottonseed meal + 4,000 IU vitamin E x animal(-1) x d(-1)). Supplements based on cottonseed meal provided 43.5 g of total gossypol/d (37% negative isomer (-) and 63% positive isomer (+)). Blood samples were collected at the start of the experiment and every 3 wk thereafter up to 12 wk. Plasma a-tocopherol (alpha-T) concentration was affected by treatments (P < 0.05). Heifers supplemented with cottonseed meal had greater (P < 0.05) alpha-T concentration in plasma than heifers supplemented with soybean meal at each concentration of vitamin E. Supplementation at 4,000 IU vitamin E x animal(-1) d(-1) increased (P < 0.05) the concentration of a-T in plasma. Weight gain, hemoglobin and hematocrit were not affected by treatment. Erythrocyte osmotic fragility (EOF) increased (P < 0.05) in cottonseed meal-fed animals; however, EOF was lowered (P < 0.05) with vitamin E supplementation. Heifers fed CSM and CSM+E supplements had greater (P < 0.01) concentrations of (-)-, (+)-, and total-gossypol in plasma, corpora lutea (CL), liver, and endometrium than heifers fed SBM and SBM+E supplements. Tissue alpha-T concentration increased with increased dietary supplemental vitamin E, particularly in great amounts in the CL. Because there was no adverse effect of gossypol on superovulation response or embryo development despite concentrations of gossypol in endometrium that are toxic to embryos, it is likely that systems exist in the reproductive tract to limit gossypol toxicity.

Gossypol: a contraceptive for men.

Gossypol is a polyphenol isolated from the seed, roots, and stem of the cotton plant (Gossypium sp.). The substance, a yellow pigment similar to flavonoids, is present in cottonseed oil. In the plant, it acts as a natural defensive agent against predators, provoking infertility in insects. In most animals, gossypol provokes infertility, and in man it causes spermatogenesis arrest at relatively low doses. Studies carried out in China, Africa, and Brazil have shown that the substance is well tolerated, causing no side effects that lead to discontinuation. The reported hypokalemia of early studies has not been confirmed in the latest trials. The only concern at present appears to be lack of reversibility in over 20% of subjects. Gossypol should be prescribed preferably to men who have completed their families or for those who would accept permanent infertility after a few years of use.

Oral gossypol in the treatment of patients with refractory metastatic breast cancer: a phase I/II clinical trial.

Gossypol has demonstrated in vitro effects on cell cycle regulation and anti-tumor activity against mammary carcinoma cell lines. This Phase I/II study assesses both the effect of gossypol on cell cycle regulatory proteins in vivo and the clinical effect. Twenty women with refractory metastatic breast cancer received oral gossypol at daily doses between 30 and 50 mg per day. Gossypol plasma levels were measured (n = 8) and the modulation of the retinoblastoma (Rb) gene protein and Cyclin D1 was assessed by serial biopsies (n = 4). Grade I-II toxicities with gossypol treatment included nausea in 30% of patients, fatigue 15%, emesis 15%, altered taste sensation 15% and diarrhea in 10% of patients. Two of the three patients receiving 50 mg/day experienced dose limiting dermatologic toxicity (grade III). One patient had a minor response and two patients had stable disease with > 50% decline in serial assessments of the serum tumor markers. Immunohistochemical analysis of cyclin D1 and Rb expression in serial biopsies of four patients revealed both a concurrent decrease in cyclin D1 expression and an increase in nuclear Rb expression in three patients. The maximal tolerated dose (MTD) of gossypol was 40 mg/day. Gossypol appears to affect the expression of Rb protein and cyclin D1 in breast cancer metastases at doses achievable, yet had negligible antitumor activity against anthracycline and taxane refractory metastatic breast cancer. The cell cycle regulatory effects of gossypol suggest a potential role for gossypol as a modulating agent in conjunction with other cell cycle specific compounds.

Gossypol treatment of recurrent adult malignant gliomas.

Gossypol, a polyphenolic compound which depletes cellular energy by inhibition of several intracellular dehydrogenases, has been shown to have antiproliferative activity against human glial tumor cell lines in vitro and in nude mouse xenografts. Human trials of gossypol as a male contraceptive have demonstrated safety of long-term administration. We studied the activity of Gossypol 10 mg PO bid in 27 patients with pathologically confirmed glial tumors which had recurred after radiation therapy. Fifteen patients had glioblastoma, 11 patients anaplastic astrocytoma, 1 patient relapsed low grade glioma. Response was assessed every 8 weeks using CT/MRI scan and clinical criteria including decadron requirement. Treatment was continued until disease progression. Two patients had partial response (PR); 4 had stable disease for 8 weeks or more. One patient maintained a PR with improved KPS for 78 weeks. The other had a PR lasting 8 weeks. Toxicity was mild: 2 heavily pretreated patients had mild thrombocytopenia, 5 patients developed hypokalemia, 3 patients developed grade 2 hepatic toxicity and peripheral edema. Gossypol levels measured by HPLC did not correlate with response or toxicity in this study. We conclude that gossypol is well tolerated and has a low, but measurable, response rate in a heavily pretreated, poor-prognosis group of patients with recurrent glioma. The presumed novel mechanism of action, lack of significant myelosuppression, and activity in patients with advance glioma support further study of gossypol as an antineoplastic agent.

Environmental distal renal tubular acidosis in Thailand: an enigma.

Distal renal tubular acidosis is a common health problem in northeastern Thailand, with the population background of the low potassium intake, low urine citrate, and decreased red blood cell Na-K adenosine triphosphatase (ATPase) activity and the environment of the high soil vanadium. The disease is usually seen in the people with low socioeconomic status in summer. The patients have decreased gastric acidity and low urine potassium. There are varying degrees of renal function from normal to impairment. Gastric hypoacidity is an important clue. Defects in H-K ATPase and anion exchange (AE2) mechanism are considered. The urine vanadium is higher in the patients than that of normal rural northeastern villagers. Inhibition of H-K ATPase by vanadium seems possible and requires more supporting evidence. AE1 gene mutation is noted in few patients. The cause of dRTA is not apparent. The AE2 gene and H-K ATPase gene remain to be studied. Both environmental and genetic factors could contribute to the pathogenesis of the disease.

Effect of gossypol on hepatic and serum gamma-glutamyltransferase activity in rats.

A single intraperitoneal dose (25 mg/kg) of gossypol given to male Sprague-Dawley rats caused marked changes in the activity of the hepatic and serum gamma-glutamyltransferase (GGT) and microsomal monooxygenases. The GGT activity in liver homogenate, S-9 supernatant fraction and microsomes was significantly depressed; however, the level of serum GGT was elevated. While the hepatic glutathione concentration was not greatly changed, the aminopyrine N-demethylase activity and microsomal cytochrome P450 content of the liver were significantly decreased in the treated rats. At necropsy, the livers of the treated rats appeared generally pale with distinct pinpoint foci. Histopathological examination of the liver showed degenerative changes and coagulative necrosis. The results indicate that gossypol is a strong hepatotoxic agent which can produce severe hepatic damage.

[The antifertility effect of gossypol plus testosterone and estrogen].

In order to reduce the side effect of gossypol, gossypol was used in combination with steroid hormones so that the dose of both drugs can be reduced. Silastic capsules containing testosterone (T) + estradiol (E) were implanted under the skin male wister rats for 8 weeks. After removing the implants, testosterone was given orally at the dose of 15 mg.kg-1 which is only 50% of the usual antifertility dose. Mating tests showed that the male rats became infertile. Microscopic examination of the heart, liver and kidneys showed no pathologic changes. The treated rats gained body weight as well as the controls. The fertility of the treated rats recovered four to five weeks after treatment. Thus, gossypol in combination with testosterone and estrogen exhibited a low degree of side effect and high antifertility activity.

Desarrollo y evaluación de un panqué enriquecido con harina de algodón / Development and evaluation of an enriched cake with cottonsedd meal

En Venezuela, los problemas nutricionales, específicamente la desnutrición caloricoproteica, se ha acentuado en los últimos años. Una posible solución lo constituye el enriquecimiento de alimentos con fuentes de proteínas, como las que contiene el residuo o torta de la extracción del aceite de las semillas de algodón. En este trabajo se caracterizaron las harinas de algodón obtenidas industrialmente y se utilizó hasta en un 15 por ciento en un panqué enriquecido, susceptible a ser utilizado en la merienda escolar. Se seleccionó el panqué de vainilla con 45 por ciento de harina de algodón debido a que la aceptabilidad a nivel de laboratorio fue de 97 por ciento. Se probó en una escuela con 1.009 niños de distintas edades, la aceptabilidad fue de 97 por ciento. Se concluyó que este producto, que suministra 395 Kcal y 13 g de proteínapor cada 100 g, podría ser utilizado para mejorar el aporte calóricoproteico de la merienda escolar