Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Gossypol”

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
PubMed1984

Comparative in vitro spermicidal effects of (+/-)-gossypol, (+)-gossypol, (-)-gossypol and gossypolone.

The comparative in vitro spermicidal effects of (+)-gossypol, (-)-gossypol and (+/-)-gossypol were evaluated on the spermatozoa of human, monkey, rabbit, mouse, rat and hamster. The spermicidal effects of gossypol isomers were also compared with those of gossypolone, which is a proposed major metabolite of gossypol. Gossypol isomers and gossypolone were all spermicidal. (+)- and (-)-Gossypol demonstrated spermicidal activities at the same concentration at which (+/-)-gossypol shows spermicidal effects on the spermatozoa of all species tested. However, gossypolone was less potent than the gossypol isomers. The spermicidal action of gossypol may be a nonspecific effect unrelated to the antifertility mechanism of orally administered gossypol, since (+)-gossypol which is not an effective male antifertility agent also showed the equivalent spermicidal effect to that of (+/-)-gossypol.

Animals↗
PubMedDate not supplied

Studies on the male antifertility agent--gossypol acetic acid. III. Effect of gossypol acetic acid on rat testis.

Gossypol acetic acid at the dose of 5 mg/rat/day for 2 and 4 weeks did not cause any significant effect on the body weight, testis, epididymis, seminal vesicle and prostate weight, nor gossypol treatment had any significant effect on the activities of acid phosphatase and succinic dehydrogenase in the testis. Changes in the testis ATPase activity were, however, significant after gossypol treatment. During the course of present investigations no effect of gossypol treatment on 3H thymidine incorporation into DNA of testicular cells was observed, nor there were any changes in the DNA and total protein content of the testis after gossypol treatment. Gossypol treatment did not cause any effect on the plasma Na+ level. However, transient decrease in the plasma K+ level was observed; decrease in K+ level two weeks after gossypol treatment was restored to normal after 4 weeks of gossypol treatment. No changes in the histology of the testis were observed 2 weeks after gossypol treatment but marked inhibition of spermatogenesis was observed 4 weeks after gossypol treatment. Motility of vas deferens spermatozoa was also markedly inhibited 4 weeks after gossypol treatment. In the light of the present observations and those of others, there is a clear demonstration that gossypol acts directly on the spermatozoa and on the testis; at both the sites the drug interferes in the ATPase activity.

Adenosine Triphosphatases↗
PubMedDate not supplied

Studies on the male antifertility agent--gossypol acetic acid. V. Effect of gossypol acetic acid on the fertility of male rats.

Gossypol acetic acid was given to male rats at a dose of 7.5 mg/rat/day six days a week for ten weeks. After nine weeks of gossypol treatment no implantation sites were observed in the females mated with gossypol treated males. After ten weeks of gossypol treatment all the spermatozoa in the vas deferens were non-motile. Gossypol treatment did not affect the body weight and the weights of the accessory sex organs. Plasma LH and FSH levels, hCG binding in testis and succinic dehydrogenase (SDH) and adenosine triphosphatase (ATPase) activities in liver, kidney and testis were not affected by gossypol treatment. Histological observations of the testis revealed partial damage to the seminiferous tubules. Single high doses of gossypol did not induce significant changes in the body weight and weights of testis and accessory sex organs. ATPase activity in the testis was reduced significantly after gossypol treatment, the enzyme activity in liver and kidney, was however, affected at high doses only. Gossypol treatment had no effect on the histoarchitecture of the testis. Intratesticular administration of gossypol evoked localized damage in the testis. Gossypol treatment had no effect on I125 FSH binding to the rat testis homogenate in vitro.

Animals↗
PubMed2000

Gossypol blood levels and inhibition of spermatogenesis in men taking gossypol as a contraceptive. A multicenter, international, dose-finding study.

The safety and efficacy of gossypol continues to be controversial. The aim of this study was to evaluate gossypol as a contraceptive pill for men at doses lower than those previously prescribed and in men from various ethnic origin. A total of 151 men from Brazil, Nigeria, Kenya, and China were divided into two groups. Both groups received 15 mg gossypol/day for 12 or 16 weeks to reach spermatogenesis suppression. Subjects were then randomized to either 7.5 or 10 mg/day for 40 weeks. In addition, 51 men were enrolled as a control group. In all, 81 subjects attained spermatogenesis suppression. Only one man discontinued treatment because of tiredness. Potassium levels fluctuated within the normal range. FSH increased consistently. Testicular volume decreased, but after discontinuation, values returned to levels not statistically different from admission. Of 19 subjects on the 7.5 mg/day dose group, 12 recovered sperm counts >20 million/mL within 12 months of discontinuing gossypol. In the 10 mg/day group, sperm counts recovered in only 10 of 24 subjects. Eight of the 43 patients remained azoospermic 1 year after stopping gossypol. All men diagnosed with varicocele failed to reverse spermatogenesis suppression. Gossypol blood levels indicated that sperm suppression occurs independently of concentration, whereas spermatogenesis recovery appears to be concentration-dependent. Gossypol may become a medical alternative to surgical vasectomy when the delay in onset of infertility is acceptable. When taken for 1 year, gossypol causes no reduction in sexual desire or frequency of intercourse. The possibility of reversal, occurring in 51% of the men on this regimen within 1 year after stopping gossypol, is an advantage of this compound as compared with surgical sterilization in many parts of the world.

Adult↗
PubMed1988

The effects of gossypol on nuclear protein in rat testes. II. The synthesis of histones and testis-specific proteins after gossypol treatment.

This communication is to report the effects of gossypol on the synthesis of chromosomal basic proteins in the spermiogenic cells. A double-labelling experiment has been performed. The control rats received 14C-arginine, whereas the gossypol-treated rats received a 3H-arginine injection. An equal volume of the tissues (from control and gossypol-treated) were combined, and the total nuclear basic proteins (TNBP) from round spermatids (RS) and elongating spermatids (ES) were extracted for electrophoretic separation. By studying the ratio of 3H/14C, it was indicated that the synthesis of H1, H3, H2B plus H2A and TP1 in the RS was reduced by gossypol. The amount of inhibition of these proteins were 48%, 19%, 27%, and 11%, respectively. In the ES, the synthesis of H1, H3, H2B plus H2A, H4 plus TP2, TP3, and TP1 was reduced by gossypol, the reduction was 33%, 22%, 26%, 14%, 33%, and 8%, respectively. The synthesis of S1 protein was not inhibited by gossypol in both RS and ES.

Administration, Oral↗
PubMed1986

Studies on structure-activity relationship of gossypol, gossypol ethers and three naphthaldehydes in the inhibition of spermatozoal metabolism.

Gossypol tetramethyl ether [C30 H24 O2(OCH3)4] and gossypol hexamethyl ether [C30 H24 O2(OCH3)6], which in contrast to gossypol are stable compounds, were tested for their ability to depress fructose degradation in fresh human sperm cells. Both ethers inhibited spermatozoal fructolysis, yet less effectively than did the parent compound. A synthetic compound, O-hydroxylnaphthaldehyde, and two commercially available preparations, 1- and 2-naphthaldehydes, were also tested under the same experimental conditions. These preparations represent about half of the gossypol molecule and possess a reactive aldehyde group in their molecules. Their inhibitory effect on fructose degradation in fresh human sperm cells, however, was considerably smaller than that of gossypol itself. It thus appears that the whole ring structure of gossypol rather than the intact aldehyde group is required for an effective inhibition of spermatozoal energy metabolism.

Aldehydes↗
PubMedDate not supplied

The correlation between the gossypol contents in blood plasma, rete testis fluid, and cauda epididymal fluid following chronic treatment with gossypol in rats.

Concentrations of gossypol in blood plasma, rete testis fluid, and fluid from the caudia epididymidis were measured simultaneously by high performance liquid chromatography in rats treated with gossypol (15 mg/kg daily for 3 weeks). Antispermatogenic effects were demonstrated by loss of sperm motility in the cauda epididymidis and structural changes in the testis. It was found in these treated rats that concentrations of gossypol were lower in rete testis fluid compared with blood plasma but increased significantly in fluid from the cauda epididymidis. The results indicate a restriction of the blood-testis barrier to gossypol and its local concentration in the epididymis after fluid resorption.

Animals↗
PubMed1988

The toxicology of gossypol acetic acid and (-)-gossypol.

The toxicity of gossypol has been investigated in Sprague-Dawley rats at dosages of 0, 0.5, 5.0 and 25 mg/kg per day of (+/-)-gossypol acetic acid. The most significant toxicological finding was marked suppression of body weight gain in rats receiving 25 mg/kg per day. Terminal studies showed 6 out of 20 rats receiving 25 mg/kg per day to have varying degrees of testicular pathology. Five mg/kg per day was shown to be a "no effect" level. A study in cynomolgus monkeys at 25 mg/kg per day of (+/-)-gossypol acetic acid for 13 weeks induced death, a variety of clinical signs, extensive biochemical change and pathology in the heart, liver, kidney and testes. The toxicity of (-)-gossypol was investigated in male cynomolgus monkeys at dosages of 1.5, 4 or 5 mg/kg/day for 4 weeks. No animals died. Clinical signs involving the gastrointestinal tract, adverse effects on body weight gain, consistent biochemical changes in serum proteins, calcium, inorganic phosphorus and serum cholesterol were recorded at 4 mg/kg per day and above. Morphological change was not induced.

Animals↗
PubMedDate not supplied

Studies on the male antifertility agent-gossypol acetic acid. II. Effect of gossypol acetic acid on the motility and ATPase activity of human spermatozoa.

A marked reduction in the motility of the human spermatozoa was observed when spermatozoa were incubated with 10 and 100 microgram of gossypol acetic acid for different time period at 37 degrees C; the motility was reduced from 83% to 4% after 210 minutes (P less than 0.001). A significant decrease in the activities of Ca++ and Mg++ activated ATPase in the spermatozoa was observed after gossypol treatment (P less than 0.005). Changes in the zinc++ concentration in the spermatozoa after gossypol treatment were, however, not significant. The present investigations suggest that inhibition of the sperm motility after gossypol treatment may be due to the inhibition of the ATPase activity in the spermatozoa.

Adenosine Triphosphatases↗
PubMedDate not supplied

Studies on the male antifertility agent gossypol acetic acid. VI. Effect of gossypol acetic acid on the fertility of bonnet monkey. Macaca radiata.

Gossypol acetic acid (4 mg/day/5 days a week) suspended in Tonoferon tonic was given to male bonnet monkeys, Macaca radiata, by oral route for 3 months. Marked reduction in the sperm count/ejaculate and sperm motility were observed after gossypol treatment; both motility and sperm count/ejaculate returned to the normal level 8-10 weeks after termination of gossypol treatment. The citric acid and fructose levels in the semen of gossypol treated monkeys were not different from those of the controls.

Animals↗
PubMed1990

[Studies on the resolution of racemic gossypol. III. Study on the chemical and physical properties of the amino condensates of gossypol].

Fifteen condensates of chiral amines and racemic gossypol were prepared. Their 1HNMR spectra indicated that all the amine condensates tested had the same keto-enamine structures and shifts of protons on C11, C11 of various condensates were analyzed for their structural relationship. The Rf and delta Rf values (difference between (+) and (-)gossypol condensates) on TLC of these derivatives and stability of eight condensates of (-)gossypol were examined. All these properties were discussed in light of the configuration of gossypol. These studies not only provided rational basis of selecting resolving agent, but also gave indications of their relative absorbability and stereochemistry of the condensates which might be useful in postulating their in vivo behaviors and designing derivatives with better pharmacological actions.

Gossypol↗
PubMed1984

Analysis of gossypol and gossypol-acetic acid by high-performance liquid chromatography.

Gossypol, a bis-sesquiterpenoid cotton pigment, is of current interest as a male fertility-regulating agent. For the purposes of analyzing material to be studied biologically, a method is described for the analysis of gossypol by high-performance liquid chromatography. This has been used for examining the purity of gossypol-acetic acid using a UV-absorbance ratio technique.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Studies on the male antifertility agent gossypol acetic acid. VII. Effect of motility stimulated factors on the revival of human spermatozoal motility after gossypol treatment in vitro.

Human spermatozoa were incubated with gossypol acetic acid (100 micrograms/1 X 10(6) spermatozoa/ml) at 37 degrees C for 30 min. The drug treatment inhibited the spermatozoal motility significantly. Washing of the spermatozoa, after gossypol treatment, did not effect their motility. A partial revival in the motility of the spermatozoa was observed when gossypol treated spermatozoa were incubated, after washing, with motility stimulating factors, e.g. theophylline, dibutyryl-cAMP and Kallikrein.

Bucladesine↗
PubMed1988

A bioenergetic model of gossypol action: effects of gossypol on adult rat spermatogenic cells.

Rat spermatogenic cells have glycolytic rates of 124 +/- 36 nmol lactate.mg protein-1.h-1. Maximum glycolytic rates in the absence of oxidative phosphorylation do not exceed the basal rates by greater than 40%. From the rates of oxygen consumption and lactate production it can be calculated that less than 8% of the total ATP produced by spermatogenic cells is provided by glycolysis. These properties of spermatogenic cells would render them highly susceptible to cytotoxicity due to the action of agents like gossypol that impair mitochondrial oxidative phosphorylation or to conditions that produce testicular hypoxia. The main effect of gossypol on spermatogenic cell energy metabolism is to uncouple mitochondrial oxidative phosphorylation. In the absence of glucose, this uncoupling action of gossypol would change the NAD+/NADH redox coupling and, consequently, could modify metabolic fluxes through the lactic dehydrogenase catalyzed reaction.

Adenosine Triphosphate↗
PubMed1985

Antifertility effect of polyvinylpyrrolidone-gossypol and gossypol in male rats.

Thirty-nine adult male Wistar rats were administered 20 mg/kg or 24.3 mg/kg polyvinylpyrrolidone-gossypol (PVP-G) and 20 mg/kg gossypol acetic acid (G-A) 6 times a week for 6 weeks. Mating test was taken to evaluate the antifertility effect. Caudal sperm count, body weight, sex and accessory sex organ weights were recorded. At the end of 6 weeks treatment, the recovery period of 6 weeks was investigated. The results showed that the onset of antifertility action and recovery with PVP-G are faster than with G-A.

Animals↗
PubMed1996

[Suppressive effect of Gossypol, Gossypolone and serum from Gossypol treated rats on steroidogenesis in cultured porcine granulosa cells].

Gossypol (GP), a male antifertility agent, and Gossypolone (GN), a major metabolite of GP, have been shown to have a suppressive effect on steroidogenesis in bovine luteal cells. We examined the effect of GP, GN and serum obtained from rats given GP (GP-serum) on steroidogenesis in porcine granulosa cells (PGC). To obtain GP-serum, 50-60 day old Copenhagen rats received GP (12.5 mg/kg B.W./day, sc) for 14 days. PGC were incubated with GP, GN and GP-serum at different doses for 24 hours. GP and GN significantly suppressed Progesterone (P4) and Estradiol (E2) release in a dose-dependent manner, respectively. GP-serum also significantly suppressed P4 release in a dose-dependent manner. The magnitude of suppression of P4 obtained by GP-serum could not be explained by the amount of GP remaining in the serum. Therefore, the inhibition of P4 release by GP-serum could not be solely attributed to GP.

Animals↗