Modulatory influence of tin-protoporphyrin on gossypol-induced alterations of heme oxygenase activity in male wistar rats

Effect of Heating Time of Cottonseed Meal on Nutrient and Mineral Element Digestibility in Chicken (Based on Cottonseed Meal Replaced with All Soybean Meal)

A digestibility test was conducted to estimate the effects of the heating time of cottonseed meal on nutrient digestibility and mineral element absorption in chicken. A total of 36, 45-week-old healthy New Yangzhou chickens with similar body weight were randomly divided into 6 groups with 6 replicates per group and one chicken per replicate. The chickens in Group A (control group) were fed the corn-soybean meal diet. The chickens in Groups B, C, D, E, and F (experimental groups) were fed the cottonseed meal to replace all soybean meal. The cottonseed meal in the experimental groups was treated with wet heating. The heating temperature was set at 120 °C, and the humidity was set at 50%. The heating time was set to 10, 15, 20, 25, and 30 min successively. The trial period was 4 day. The digestibility of crude protein, metabolic energy, and dry matter was highest using wet-heat treating for 15 min (p < 0.05). The digestibility of Fe increased significantly from 66.78% to 70.39% when the heating time of cottonseed meal was prolonged from 10 min to 30 min (p < 0.05). Compared with Group A, the digestibility of Zn was increased in Groups B and C, and then there was a decrease in Group D. Finally, the digestibility was increased again in Group F. The opposite pattern was shown in the digestibility of Cu and Zn. There was no significant effect of wet heat treatment time on the digestibility of calcium, phosphorus, and manganese (p > 0.05). When cottonseed meal is considered as feed for 45-week-old chickens, processing conditions of 120 °C and 50% humidity for 15 min are recommended.

Gossypol inhibits cullin neddylation by targeting SAG-CUL5 and RBX1-CUL1 complexes

Cullin-RING E3 ligase (CRL) is the largest family of E3 ubiquitin ligase, responsible for ubiquitylation of ∼20% of cellular proteins. CRL plays an important role in many biological processes, particularly in cancers due to abnormal activation. CRL activation requires neddylation, an enzymatic cascade transferring small ubiquitin-like protein NEDD8 to a conserved lysine residue on cullin proteins. Recent studies have validated that neddylation is an attractive anticancer target. In this study, we report the establishment of an Alpha-Screen-based high throughput screen (HTS) assay for in vitro CUL5 neddylation, and screened a library of 17,000 compounds including FDA approved drugs, natural products and synthetic drug-like small-molecule compounds. Gossypol, a natural compound derived from cotton seed, was identified as an inhibitor of cullin neddylation. Biochemical studies showed that gossypol blocked neddylation of both CUL5 and CUL1 through direct binding to SAG-CUL5 or RBX1-CUL1 complex, and CUL5-H572 plays a key role for gossypol binding. On cellular level, gossypol inhibited cullin neddylation in a variety of cancer cell lines and selectively caused accumulation of NOXA and MCL1, the substrates of CUL5 and CUL1, respectively, in multiple cancer cell lines. Combination of gossypol with specific MCL1 inhibitor synergistically suppress growth of human cancer cells. Our study revealed a previously unknown anti-cancer mechanism of gossypol with potential to develop a new class of neddylation inhibitors.

Recent advances in gossypol derivatives and analogs: a chemistry and biology view

Gossypol as a natural occurring polyphenol has been studied in a wide range of therapeutic contexts for a long time. The chemical modifications on gossypol were limited due to the unique chemical properties of polyphenols. The design and synthesis of gossypol derivatives and the exploration of their biological activities are the interest of the synthetic chemists, medicinal chemists and pharmacologists. Thus, the progress of diverse gossypol derivatives and analogs' synthesis, biological activities, mechanism elucidation and drug discovery based on gossypol scaffold is summarized.

Gossypol-induced suicidal erythrocyte death

Side effects of gossypol, a polyphenolic component of Gossypium, with male contraceptive, anticancer, antimicrobial and antiviral activities include anemia due to accelerated demise of erythrocytes. Erythrocytes may be cleared from circulating blood following apoptosis-like suicidal death or eryptosis. Hallmarks of eryptosis are cell shrinkage and cell membrane scrambling with subsequent phosphatidylserine-exposure at the cell surface. Stimulators of eryptosis include increase of cytosolic Ca(2+)-activity ([Ca(2+)](i)). The present study explored, whether gossypol stimulates eryptosis of human erythrocytes. Utilizing flow cytometry, [Ca(2+)](i) was estimated from Fluo-3 fluorescence, cell volume from forward scatter, phosphatidylserine-exposure from annexin-V-binding, and hemolysis from hemoglobin release. A 48 h exposure to gossypol (0.75 μM) significantly increased [Ca(2+)](i), decreased forward scatter and increased annexin-V-binding. Gossypol exposure was followed by a slight but significant increase of hemolysis. Removal of extracellular Ca(2+) significantly blunted the effect of gossypol (1 μM) on annexin-V-binding. The present observations reveal a novel effect of gossypol on human erythrocytes, which contributes to or even accounts for the triggering of anemia by this substance.