Gossypol

1 Thespesia sp.

Growth inhibitory effects of gossypol and related compounds on fungal cotton root pathogens.[Pubmed:24713043]

Lett Appl Microbiol. 2014 Aug;59(2):161-8.

UNLABELLED: The effect of the terpenoids Gossypol, 6-methoxyGossypol, 6,6'-dimethoxyGossypol, Gossypolone and apoGossypolone on growth of fungal soil pathogens was investigated. The compounds were tested at a concentration of 100 mug ml(-1) in a Czapek Dox agar medium at 25 degrees C. Gossypol, Gossypolone and apoGossypolone demonstrated strong growth inhibitory activity (>/=90%) against Pythium irregulare, Pythium ultimum and Fusarium oxysporum. These same terpenoids provided good growth inhibition against most Rhizoctonia solani isolates. Methylated Gossypol derivatives generally yielded reduced growth inhibition against the tested fungi compared with Gossypol. Dose-response effects of Gossypol, Gossypolone and apoGossypolone were determined over a concentration range of 5-100 mug ml(-1) against P. irregulare CR1, P. ultimum ATCC 56081 and R. solani CR15. At lower concentrations, Gossypol proved to be a more potent growth inhibitor of P. irregulare (ED50 = 4 mug ml(-1) ) and P. ultimum (ED50 = 13.2 mug ml(-1) ) than the other tested compounds. Rhizoctonia solani CR15 was more resistant to growth inhibitory effects of all tested terpenoids (ED50 = 35-43 mug ml(-1) ). SIGNIFICANCE AND IMPACT OF THE STUDY: This work demonstrates that Gossypol is an effective natural antimicrobial agent against a wide range of potential fungal pathogens of cotton. Relative to Gossypol, methylated Gossypol derivatives that are also found naturally in root tissue were less effective at inhibiting the growth of soil fungal pathogens. However, by virtue of their significant concentration in root tissue, they still may contribute to cotton defence.

Gossypol increases expression of the pro-apoptotic BH3-only protein NOXA through a novel mechanism involving phospholipase A2, cytoplasmic calcium, and endoplasmic reticulum stress.[Pubmed:24778183]

J Biol Chem. 2014 Jun 6;289(23):16190-9.

Gossypol is a putative BH3 mimetic proposed to inhibit BCL2 and BCLXL based on cell-free assays. We demonstrated previously that Gossypol failed to directly inhibit BCL2 in cells or induce apoptosis in chronic lymphocytic leukemia (CLL) cells or platelets, which require BCL2 or BCLXL, respectively, for survival. Here, we demonstrate that Gossypol rapidly increased activity of phospholipase A2 (PLA2), which led to an increase in cytoplasmic calcium, endoplasmic reticulum (ER) stress, and up-regulation of the BH3-only protein NOXA. Pretreatment with the PLA2 inhibitor, aristolochic acid, abrogated the increase in calcium, ER stress, and NOXA. Calcium chelation also abrogated the Gossypol-induced increase in calcium, ER stress, and NOXA, but not the increase in PLA2 activity, indicating that PLA2 is upstream of these events. In addition, incubating cells with the two products of PLA2 (lysophosphatidic acid and arachidonic acid) mimicked treatment with Gossypol. NOXA is a pro-apoptotic protein that functions by binding the BCL2 family proteins MCL1 and BFL1. The BCL2 inhibitor ABT-199 is currently in clinical trials for CLL. Resistance to ABT-199 can occur from up-regulation of other BCL2 family proteins, and this resistance can be mimicked by culturing CLL cells on CD154(+) stroma cells. We report here that AT-101, a derivative of Gossypol in clinical trials, overcomes stroma-mediated resistance to ABT-199 in primary CLL cells, suggesting that a combination of these drugs may be efficacious in the clinic.

Identification of glucuronidation and biliary excretion as the main mechanisms for gossypol clearance: in vivo and in vitro evidence.[Pubmed:24555821]

Xenobiotica. 2014 Aug;44(8):696-707.

1. The natural polyphenol Gossypol possesses many therapeutic benefits. Here we aim to determine the elimination pathways of Gossypol in vivo and in vitro. 2. Metabolite elucidation of Gossypol was performed using UPLC-QTOF/MS coupled with Metabolynx analysis. Clearance of Gossypol was evaluated in bile duct cannulated rats and in the single-pass perfused rat intestine model. In vitro glucuronidation of Gossypol was characterized using liver and intestine microsomes as well as recombinant UDP-glucuronosyltransferase (UGT) enzymes. 3. Analysis of rat plasma, urine, and feces revealed glucuronidation as the only metabolic pathway for Gossypol. In bile duct cannulated rats, considerable amounts of glucuronides (G1, G2 and G3; 58.8-83.2% of dose) and parent compound (5.0-20%) were excreted into bile after IV administration. In the perfused rat intestine model, Gossypol was well absorbed with a [Formula: see text] (the dimensionless effective permeability) value of 4.4. Significant amounts of glucuronides (G1, G2 and G3) were excreted into the gut lumen (2.5%) and into the bile (4.8%). Biliary excretion of unchanged Gossypol (6.0%) was comparable to that of glucuronides. Further, Gossypol was subjected to rapid glucuronidation by liver and intestine microsomes. Reaction phenotyping showed that multiple UGT1A enzymes (including UGT1A1, 1A3, 1A7 and 1A8) are mainly responsible for Gossypol metabolism. 4. In conclusion, glucuronidation was the only metabolic pathway for Gossypol in rats. Excretion of unchanged Gossypol into bile was also an important clearance mechanism.

Effects of dietary gossypol concentration on growth performance, blood profiles, and hepatic histopathology in meat ducks.[Pubmed:24902707]

Poult Sci. 2014 Aug;93(8):2000-9.

The objective of this study was to determine the effects of Gossypol from cottonseed meal (CSM) on growth performance, blood biochemical profiles, and liver histopathology of ducks. A total of 900 1-d-old ducks were randomly allocated to 5 treatments with 12 pens/treatment and 15 ducks/pen. The 5 experimental diets were formulated in such a way that 0% (a corn-soybean meal basal diet, diet 1), 25% (diet 2), 50% (diet 3), 75% (diet 4), and 100% (diet 5) of protein from soybean meal were replaced with that from CSM. All diets were formulated on a digestible amino acid basis. The experiment included 2 phases, the starter phase (1 to 3 wk) where the test diets contained graded levels of CSM and the growth phase (4 to 5 wk) where birds were fed a corn-soybean basal diet to examine the recovery of ducks after CSM withdrawal. Dietary CSM and Gossypol linearly (P < 0.01) and quadratically (P < 0.01) decreased ADG and ADFI during d 1 to 14. The threshold of daily total Gossypol (TG) and free Gossypol (FG) intake based on ADG on d 1 to 7 and d 7 to 14 were 32.20 and 2.64 mg/d, and 92.12 and 9.62 mg/d, respectively. Serum alanine aminotransferase increased (P < 0.05) linearly with increasing level of Gossypol in the diets (d 7), whereas aspartate aminotransferase increased (P < 0.05) linearly and quadratically (d 14). Serum albumin concentration decreased (P < 0.05) quadratically with increasing dietary CSM concentrations on d 21. The degree of damage to the liver increased markedly with increasing dietary CSM and Gossypol content and the length of CSM and Gossypol intake. On d 35, there was no difference on BW and blood profiles of ducks among all treatments. These results suggest that meat ducks' dietary TG and FG concentration should be lower than 928.9 and 77.2 mg/kg, respectively, during d 1 to 21 of age and that a 2-wk withdrawal of diets containing Gossypol should be considered.

Molecular mechanism of gossypol-induced cell growth inhibition and cell death of HT-29 human colon carcinoma cells.[Pubmed:12818369]

Biochem Pharmacol. 2003 Jul 1;66(1):93-103.

Gossypol, a male contraceptive drug, has been demonstrated to have antiproliferative and antimetastatic effects on many kinds of cancer cells in vitro. HT-29 human carcinoma cell line is one of the most susceptible cell lines to Gossypol-induced cell death. Here, it is shown that treatment of HT-29 cells with Gossypol not only induces cell cycle arrest on the G0/G1 phase, but also induces apoptosis. With a serial of Western blot analysis, it is revealed that Gossypol-induced cell cycle arrest is involved in P21 up-regulation and cyclin D1 down-regulation; Gossypol-induced apoptosis triggers down-regulation of anti-apoptosis Bcl-2 members: Bcl-X(L), Bag-1 and Mcl-1, up-regulation of pro-apoptosis Bcl-2 member Bak, activation of caspase-3, -6, -7, -8, and -9, up-regulation of Apaf-1, release of cytochrome c (cyto-c) from mitochondria, and activation of both DFF45 and PARP. Taken together, Gossypol-induced cell death initiates extensive alterations of cell cycle and apoptosis proteins. Gossypol-induced apoptosis of HT-29 cells is through first the mitochondrial pathway, then the death receptor pathway, and the mitochondria pathway is, at least in part, involved in cyto-c release.

Gossypol: a contraceptive for men.[Pubmed:12020773]

Contraception. 2002 Apr;65(4):259-63.

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.

Gossypol: prototype of inhibitors targeted to dinucleotide folds.[Pubmed:10702620]

Curr Med Chem. 2000 Apr;7(4):479-98.

Gossypol, a disesquiterpene from cottonseed, exhibits multiple biological properties, including male antifertility activity and anticancer activity. Gossypol also inhibits the growth of numerous parasitic organisms and shows antiviral activity against a number of enveloped viruses, including the AIDS virus. Derivatives of Gossypol, in which the aldehyde functional groups that contribute to toxicity have been modified, retain or even show enhanced biological activity. Ring substituted 2,3-dihydroxy-1-naphthoic acids, which are structural analogs of Gossypol, share with Gossypol the ability to complex with dehydrogenases at the dinucleotide fold (Rossmann fold) with selectivity, suggesting that Gossypol may be considered the prototype of a new class of drugs targeted to dehydrogenases. Most of the biological activities of Gossypol and related compounds may result from inhibition of dehydrogenases.

Gossypol, a natural product isolated from cottonseeds and roots, binds to Bcl-xL protein and Bcl-2 protein with Kis of 0.5-0.6 μM and 0.2-0.3 mM, respectively.

Gossypol,303-45-7,90141-22-3;AT-101;AT101,Natural Products, buy Gossypol , Gossypol supplier , purchase Gossypol , Gossypol cost , Gossypol manufacturer , order Gossypol , high purity Gossypol