Spermatogenesis and steroidogenesis disruption in a model of metabolic syndrome rats

Esculeoside A alleviates reproductive toxicity in streptozotocin-diabetic rats' s model by activating Nrf2 signaling

This examination studied if Esculeoside A (ESA) alleviates reproductive toxicity in a type 1 diabetes mellitus (T1DM) rat model and if activating Nrf2 underlies this protection. T1DM was established by a single injection of STZ. Aged-matched adult control and STZ-DM rats were administered either the vehicle (5% carboxymethyl cellulose) or ESA (100 mg/kg). An additional group [STZ-DM + ESA (100 mg) + brusatol (2 m/kg] was added. All treatments were conducted for 16 weeks. ESA failed to attenuate weight loss, hyperglycemia, and hypoinsulinemia but significantly attenuated the associated dyslipidemia in STZ-DM rats. In parallel, ESA also enhanced total sperm count, motility, survival, reduced head and tail sperm abnormalities, increased circulatory concentrations of follicular stimulating hormone (FSH), testosterone, and Luteinizing hormone (LH), and stimulated the testicular expression of several steroidogenic enzymes (StAR, CYP11A1, CYP17A1, 3β-HSD1) in STZ-DM rats. These observations were associated with a higher testicular increase in the transcription, protein levels, and nuclear activities of Nrf2 that coincided with a reduction in the total levels of MDA and keap1 and a significant increase in the total levels of some antioxidants such as HO-1, SOD, and GSH. In concomitance, ESA reduced the testicular mRNA and nuclear concentrations of NF-κB and depressed the levels of TNF-α and IL-6. Brusatol prevented all these protective effects of ESA. In conclusion, activation of Nrf2 triggers the protective potential of ESA against reproductive toxicity in STZ-DM rats.

Long-term consumption of fermented pork fat-based diets differing in calorie, fat content, and fatty acid levels mediates oxidative stress, inflammation, redox imbalance, germ cell apoptosis, disruption of steroidogenesis, and testicular dysfunction in Wistar rats

There is a dearth of experimental evidence available as to whether the consumption of fermented pork fat (FPF) food has any harmful effects on metabolism and reproduction due to its excessive calories, high fat content, and fatty acid methyl ester (FAME) levels. We hypothesized that exposure to a FPF-diet with excessive calories, a high fat content, and high FAME levels alters testicular physiology and metabolism, leading to permanent damage to the testicular system and its function. Thirteen-week-old male rats (n = 20) were assigned to a high-calorie, high-fat diet (FPF-H, fat-60%, 23 kJ/g), a moderate-calorie, moderate-fat diet (FPF-M, fat-30%, 17.5 kJ/g), a low-calorie and low-fat diet (FPF-L, fat-15%, 14.21 kJ/g) compared to the standard diet (Control, fat-11%, 12.56 kJ/g) orally for 90 days. GC-MS analysis of the three FPF-diets showed high quantities of saturated fatty acids (SFAs) and polyunsaturated fatty acids-ω6 (PUFA-ω6) and low levels of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids-ω3 (PUFA-ω3) compared to the control diet. Consequently, the levels of serum FAMEs of the FPF-diet fed rats were significantly increased. In addition, a high level of n-6:n-3 PUFA towards PUFA-ω6 was observed in the serum of FPF-diet fed rats due to the high content of linoleic, γ-linolenic, and arachidonic acid. Long-term consumption of FPF-diets disturbed the anthropometrical, nutritional, physiological, and metabolic profiles. Furthermore, administration of FPF-diets generated metabolic syndrome (dyslipidemia, leptinemia, insulin resistance, obesity, hepato-renal disorder and function), increased the cardiovascular risk factors, and triggered serum and testis inflammatory markers (interleukin-1↑, interleukin-6↑, interleukin-10↓, leukotriene B4↑, prostaglandin↑, nitric oxide↑, myeloperoxidase↑, lactate dehydrogenase↑, and tumor necrosis factor-α↑). Activated testis oxidative stress (conjugated dienes↑, lipid hydroperoxides↑, malondialdehyde↑, protein carbonyl↑, and fragmented DNA↑) and depleted antioxidant reserve (catalase↓, superoxide dismutase↓, glutathione S-transferase↓, reduced glutathione↓, glutathione disulfide↑, and GSH:GSSG ratio↓) were observed in FPF-diet fed rats. Disrupted testis histoarchitecture, progressive deterioration of spermatogenesis, poor sperm quality and functional indices, significant alterations in the reproductive hormones (serum and testis testosterone↓, serum estradiol↑, serum luteinizing hormone↓, and follicle-stimulating hormone↑), were noted in rats fed with FPF diets than in the control diet. Severe steroidogenic impairment (steroidogenic acute regulatory protein, StAR↓; 3β-hydroxysteroid dehydrogenase, 3β-HSD↓; and luteinizing hormone receptor, LHR↓), deficiency in germ cells proliferation (proliferating cell nuclear antigen, PCNA↓), and abnormally enhanced testicular germ cell apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, TUNEL assay↑; B-cell lymphoma-2, BCL-2↓; Bcl-2-associated X protein, BAX↑; and BAX/BCL-2 ratio↑) were remarked in the FPF-diet administered rats in comparison with the control diet. In conclusion, the long-term feeding of an FPF-diet with excessive calories, a high fat content, and high FAME levels induced oxidative stress, inflammation, and apoptosis, resulting in metabolic syndrome and hampering male reproductive system and functions. Therefore, the adoption of FPF diets correlates with irreversible changes in testis metabolism, steroidogenesis, germ cell proliferation, and apoptosis, which are related to permanent damage to the testicular system and function later in life.

Marginal Zinc Deficiency in Mice Increased the Number of Abnormal Sperm and Altered the Expression Level of Spermatogenesis-Related Genes

Marginal zinc deficiency is more common than severe zinc deficiency, and the effect of marginal zinc deficiency on male reproduction is unknown. This study investigated the effect of marginal zinc deficiency on spermatogenesis and its mechanism. Male ICR mice were fed normal zinc (30 mg/kg) and marginal zinc deficiency (10 mg/kg) diets for 35 days. Zinc-dependent proteins and enzymes were measured as biomarkers of zinc levels in the body. Metallothionein and Cu-Zn SOD levels in the control group were higher than those in the marginal zinc deficiency group. Hematoxylin and eosin staining showed that the marginal zinc deficiency diet caused histopathological changes in the testis and destruction of the sperm head under scanning electron microscopy. Sperm parameters and sex hormone levels were also affected by marginal zinc deficiency. In addition, marginal zinc deficiency led to alter expression level of several important spermatogenesis-related genes in the epididymis and testes. These results indicate that although zinc intake in marginal zinc deficiency is close to the recommended reference value, low zinc intake interferes with the expression of genes related to spermatogenesis and may lead to sperm abnormalities in mice.