In vitro study of gossypol's ovarian toxicity to rodents and goats

Comparison of amino acid digestibility of soybean meal, cottonseed meal, and low-gossypol cottonseed meal between broilers and laying hens

OBJECTIVE

This study aimed to determine and compare the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of amino acids (AA) in soybean meal (SBM), cottonseed meal (CSM), and low-gossypol cottonseed meal (LCSM) fed to broiler chickens and laying hens.

METHODS

Three semi-purified diets containing the identical crude protein concentration at 20% were formulated to contain SBM, CSM, or LCSM as the sole source of N. A N-free diet was also formulated to estimate the basal ileal endogenous losses of AA for broilers and hens. A total of 300 male Ross 308 chicks at one-day-old and 144 Hy-Line Brown laying hens at 30-week-old with initial egg production rate of 88.3%±1.0% were randomly allocated into 1 of 4 dietary treatments, respectively.

RESULTS

CSM and LCSM showed more Arg and Cys+Met while less Lys, Ile, Leu, and Thr relative to SBM. Significant interactions existed between species and experimental diets for AID (except for Arg, Asp, Glu, Gly, and Pro) and SID (except for Arg, His, and Phe) of most AA. Most AA in diets showed higher AID (except for Lys) and SID (except for Lys, Met, and Ser) in broilers relative to laying hens. The AID and SID of all AA were significantly different between the three diets. In broilers, the AID and SID of most indispensable AA except for Arg in SBM and LCSM was higher than CSM. In laying hens, the AID and SID of most indispensable AA except for Arg, Met+Cys, and Phe in SBM was higher than CSM and LCSM.

CONCLUSION

The accurate determination of AID and SID of AA in CSM and LCSM for broilers and layers benefits the application of CSM and LCSM in chicken diets. The cottonseed by-products CSM or LCSM showed the species-specific AA digestibility values for broilers and layers.

Lactate metabolism in rheumatoid arthritis: Pathogenic mechanisms and therapeutic intervention with natural compounds

BACKGROUND

Rheumatoid arthritis (RA) is a common chronic and systemic autoimmune disease characterized by persistent inflammation and hyperplasia of the synovial membrane, the degradation of cartilage, and the erosion of bones in diarthrodial joints. The inflamed joints of patients with RA have been recognized to be a site of hypoxic microenvironment which results in an imbalance of lactate metabolism and the accumulation of lactate. Lactate is no longer considered solely a metabolic waste product of glycolysis, but also a combustion aid in the progression of RA from the early stages of inflammation to the late stages of bone destruction.

PURPOSE

To review the pathogenic mechanisms of lactate metabolism in RA and investigate the potential of natural compounds for treating RA linked to the regulation of imbalance in lactate metabolism.

METHODS

Research advances in our understanding of lactate metabolism in the pathogenesis of RA and novel pharmacological approaches of natural compounds by targeting lactate metabolic signaling were comprehensively reviewed and deeply discussed.

RESULTS

Lactate produced by RA synovial fibroblasts (RASFs) acts on targeted cells such as T cells, macrophages, dendritic cells and osteoclasts, and affects their differentiation, activation and function to accelerate the development of RA. Many natural compounds show therapeutic potential for RA by regulating glycolytic rate-limiting enzymes to limit lactate production, and affecting monocarboxylate transporter and acetyl-CoA carboxylase to inhibit lactate transport and conversion.

CONCLUSION

Regulation of imbalance in lactate metabolism offers novel therapeutic approaches for RA, and natural compounds capable of targeting lactate metabolic signaling constitute potential candidates for development of drugs RA.

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.

Cottonseed Kernel Powder as a Natural Health Supplement: An Approach to Reduce the Gossypol Content and Maximize the Nutritional Benefits

Cottonseed is one of the important by-products of the cotton crop. Researchers claim that cottonseed with less than 0.45% of gossypol is quite good for human consumption and animal feeding because it is a rich source of protein, edible oil, and energy. Total and free gossypols are the influencing parameters that reduce the edible nature of the cottonseed. In the present work, multiple quadratic regression models have been prepared to predict the reduction in the free and total gossypol percent. This response surface method (RSM)-based approach was applied to investigate the combined effect between input parameters such as acetone level, time of extraction, liquid-to-solid ratio (LSR), and the number of extraction cycles, whereas output responses are free and total gossypol reduction percentage. Analysis of Variance (ANOVA) has been performed to determine the highly significant parameter. The optimum combination of input parameters was determined using the RSM-based desirability approach, and confirmatory experiments were performed to validate the combination. Results revealed that the number of extraction cycles and liquid-to-solid ratio significantly affects the reduction of free and total gossypol levels. The values of r-square were found above 0.9, which indicates that the developed models are suitable and reliable for predicting free and total gossypol reduction percentage.

Intramolecular Annulation of Gossypol by Laccase to Produce Safe Cottonseed Protein

The presence of the phenol gossypol has severely limited the utilization of cottonseed meal and oil in the food and animal feed industries. Highly efficient means of biodegradation of gossypol and an understanding of the cytotoxicity of its degradation products remain outside current knowledge and are of universal interest. In this work, we showed for the first time that laccase can catalyze the intramolecular annulation of the aldehyde and hydroxyl groups of gossypol for the o-semiquinone radical and originate the released ·OH radical. It was further found that the oxidation of aldehyde groups significantly decreases reproductive toxicity and hepatotoxicity. These results indicate a novel detoxification pathway for gossypol and reveal the crucial role played by radical species in cyclization. This discovery could facilitate the development of safe, convenient, and low-cost industrial methods for the detoxification of cotton protein and oil resources.

Neuroinflammation Induction and Alteration of Hippocampal Neurogenesis in Mice Following Developmental Exposure to Gossypol

BACKGROUND

Neurogenesis in the neonatal period involves the proliferation and differentiation of neuronal stem/progenitor cells and the establishment of synaptic connections. This process plays a critical role in determining the normal development and maturation of the brain throughout life. Exposure to certain physical or chemical factors during the perinatal period can lead to many neuropathological defects that cause high cognitive dysfunction and are accompanied by abnormal hippocampal neurogenesis and plasticity. As an endocrine disruptor, gossypol is generally known to exert detrimental effects in animals exposed under experimental conditions. However, it is unclear whether gossypol affects neurogenesis in the hippocampal dentate gyrus during early developmental stages.

METHODS

Pregnant Institute of Cancer Research mice were treated with gossypol at a daily dose of 0, 20, and 50 mg/kg body weight from embryonic day 6.5 to postnatal day (P) 21. The changes of hippocampal neurogenesis as well as potential mechanisms were investigated by 5-bromo-2-deoxyuridine labeling, behavioral tests, immunofluorescence, quantitative reverse transcription-polymerase chain reaction, and western-blot analyses.

RESULTS

At P8, maternal gossypol exposure impaired neural stem cell proliferation in the dentate gyrus and decreased the number of newborn cells as a result of reduced proliferation of BLBP+ radial glial cells and Tbr2+ intermediate progenitor cells. At P21, the numbers of NeuN+ neurons and parvalbumin+ γ-aminobutyric acid-ergic interneurons were increased following 50 mg/kg gossypol exposure. In addition, gossypol induced hippocampal neuroinflammation, which may contribute to behavioral abnormalities and cognitive deficits and decrease synaptic plasticity.

CONCLUSIONS

Our findings suggest that developmental gossypol exposure affects hippocampal neurogenesis by targeting the proliferation and differentiation of neuronal stem/progenitor cells, cognitive functions, and neuroinflammation. The present data provide novel insights into the neurotoxic effects of gossypol on offspring.