Association between duration of obesity and severity of ovarian dysfunction in rat-cafeteria diet approach

Cafeteria Diet-Induced Obesity Alters Uterine Function by Disrupting Insulin and Sex Steroid Actions in Rats

BACKGROUND

The cafeteria diet (CAFD) model leads to obesity in rats, disrupting glucose metabolism, hormonal balance, and ovarian function, which results in macrosomic offspring. Insulin and ovarian hormones are essential for uterine growth, but there is limited research on how CAFD-induced obesity affects uterine function by modulating hormonal concentrations.

OBJECTIVE

This study aimed to assess how CAFD-induced obesity impacts uterine function in adult female rats by analyzing concentration of ovarian steroids and insulin,along with uterine responses.

METHODS

Postweaning female Sprague-Dawley rats (22 d), were divided into a control group fed pelleted rat chow and an obese group fed energy-dense snacks (CAFD) and pelleted rat chow for 32 wk. Body weight, food intake, energy intake, and estrous cycles were monitored during the experiment. After the experimental period, the uterine tissues were evaluated histologically, and protein expression was analyzed using western blotting and immunofluorescence. Serum hormone concentrations were assessed by ELISA, and uterine oxidative stress markers (superoxide dismutase, catalase, reduced glutathione, lipid peroxidase, and vitamin C) were measured using spectrophotometric methods.

RESULTS

CAFD-fed rats exhibited increased body weight, BMI, and abdominal girth, along with hyperglycemia, extended estrous cycles averaging 8.9 d and 40% reduction in uterine weight (P < 0.0001). The expression of proliferating cell nuclear antigen was elevated (P < 0.0001), with a significant increase in uterine cell proliferation. Obese rats showed lower concentrations of superoxide dismutase, reduced glutathione, and vitamin C, whereas concentrations of lipid peroxidase and catalase were higher in uteri (P < 0.0001). Exposure to CAFD significantly reduced serum concentrations of prolactin, progesterone, and estradiol. Moreover, progesterone receptor and its target molecules (Indian hedgehog homolog, peroxisome proliferator-activated receptor γ, and prolactin receptor) were upregulated, whereas estrogen receptor-α (P < 0.0001) and its responsive molecules (vascular endothelial growth factor and homeobox A11) were downregulated (P < 0.0001).

CONCLUSION

Consumption of CAFD causes obesity, which reduces ovarian steroid and insulin secretion and increases oxidative stress in the rat uterus, altering the expression of key molecules vital for uterine function.

Effects of coenzyme q10 supplementation on metabolic and reproductive outcomes in obese rats

Obesity, a global epidemic, is linked to adverse reproductive outcomes, including infertility and ovulation dysfunction. The cafeteria diet (CAF) serves as an animal model mirroring Western diet habit. Coenzyme Q10 (CoQ10), known for enhancing reproductive outcomes in various pathologies, is not fully understood for its effects on obesity treatment. Here, obesity was modeled using CAF-fed rats to assess CoQ10's impact on metabolic and ovarian disruptions caused by obesity. Wistar rats were divided into control (standard diet) and obese (CAF diet) groups. After 75 days, half of each group received oral CoQ10 (5 mg/kg) for 13 days, while the rest received a vehicle. Animals were euthanized during the estrus phase, and blood and ovaries were collected for analysis. CAF caused increased body weight gain (p < 0.01) associated with hyperglycemia, hypertriglyceridemia, and hypercholesterolemia (p < 0.05). Moreover, it caused a reduction in the number of AMH + follicles (p < 0.001), increasing follicular atresia (p < 0.05) and serum estradiol levels (p < 0.05). Obesity also altered the estrous cycle and reduced the ovulation rate (p < 0.05). CoQ10 administration showed beneficial effects on all ovarian disruptions but had no effect on the metabolic alterations induced by obesity. In summary, CoQ10 could be an additional treatment for obesity-related infertility in patients with normal metabolic profiles. While CoQ10 does not affect metabolic parameters influenced by obesity, crucial for reproductive issues and offspring health, it is recommended as part of a treatment plan that includes a balanced diet and increased physical activity for obese individuals with metabolic alterations seeking pregnancy.

Increased susceptibility to diet-induced obesity in female mice impairs ovarian steroidogenesis: The role of elevated leptin signalling on nodal activity inhibition in theca cells

OBJECTIVES

Susceptibility to obesity in humans is driven by the intricate interplay of genetic, environmental and behavioural factors. Moreover, the mechanisms linking maternal obesity to infertility remain largely understudied. In this study, we investigated how variable susceptibility to obesity in mice affects ovarian steroidogenesis, with a particular focus on the leptin-mediated dysregulation of Nodal signalling pathway in theca cells (TC).

METHODS

C56BL/6J (B6) and 129S1/SvlmJ (129) mice, models of maternal obesity (MO), were fed a chow diet (CD) and a high fat diet (HFD) for 16 weeks. To investigate the contrasting effects of leptin on ovarian steroidogenesis, B6 mice pharmacologically treated with leptin for 16 days on CD were used to model hyperleptinemia, while homozygous ob/ob (-/-) mice with genetic leptin deficiency, also on a CD, were used to examine the effects of obesity in the absence of leptin. Following the characterisation of the mouse phenotype, gonadal fat (GON), whole ovaries (WO), ovarian TC and granulosa cell (GC) fractions were collected for mRNA transcription and protein expression analysis. Finally, in vitro treated ovarian explants obtained from B6 mice were used to further elucidate the effects of Nodal on steroidogenesis.

RESULTS

The significant gain in body weight (BW) and fat mass (FM) in HFD-fed B6 mice (p < 0.05), was associated with increased mRNA transcription of the adipose tissue expansion genes Polymerase I and transcript release factor (Cavin), Secreted frizzled-related protein 5 (Sfrp5) and Mesoderm specific transcript (Mest) in GON (p < 0.05). Furthermore, the HFD-fed B6 mice presented also impaired glucose metabolism and insulin sensitivity (p < 0.05). In contrast, the HFD-fed 129 mice exhibited no changes in BW and FM, maintaining glucose and insulin metabolism. At the ovarian level, decreased protein expression of Steroidogenic Acute Regulatory Protein (StAR) in WO obtained from HFD-fed B6 mice (p = 0.05), was followed by reduced transcription of key steroidogenic genes like Star and Cytochrome P450 17a1 (Cyp17a) in TC (p < 0.05). Furthermore, the transcription of Nodal and its receptors was downregulated (p < 0.05), whereas mRNA levels of Suppressor of cytokine signalling 3 (Socs3) and SMAD family member 7 (Smad7) were upregulated in TC obtained from HFD-fed B6 mice (p < 0.05). No changes were seen in the genes regulating steroidogenesis, Nodal signalling, or Socs3 and Smad7 activity in the ovaries of HFD-fed 129 mice. Importantly, the pharmacological treatment of lean mice with leptin, upregulated the ovarian transcription of Socs3 and Smad7, while downregulating Nodal and its receptors (p < 0.05). Finally, in vitro pharmacological inhibition of Nodal signalling pathway in ovarian explants isolated from CD-fed B6 mice decreased the transcription of Star and Cyp17a in TC (p < 0.05), whereas Nodal treatment of explants obtained from HFD-fed B6 mice restored the transcription of both genes (p < 0.05).

CONCLUSIONS

Increased susceptibility to obesity in MO is associated with systemic hyperleptinemia and hypoestrogenism due to compromised ovarian steroidogenesis, largely driven by the inhibitory effects of leptin-Smad7 pathway on Nodal signalling activity in the TC compartment of ovarian follicles.

High-fat diet and fructose drink introduced after weaning rats, induces a better human obesity model than very high-fat diet

In the present study, we associated a high-fat diet (HF group: 45% kcal from lipids) or very high-fat (VHF group: 60% kcal from lipids) diet with a fructose drink (10% fructose) for hydration. Normal rat chow that received the control diet (content 16.3% kcal from lipid-AIN93G) and water. The treatments were introduced soon after weaning and were administered for 70 days. We aimed to compare HF and VHF groups and find which acts as a better model mimicking human obesity. Body mass gain, final body weight, adipocyte area in inguinal depots, visceral and subcutaneous adipose depots, serum triacylglycerol, and VLDL-c were all higher in the HF group, followed by the VHF group, compared to the C group. Only the HF group showed hyperinsulinemia and hyperleptinemia and higher total caloric intake, Lee index, HOMA2-IR, and total cholesterol. Serum TNF-α and IL-6 levels were lower in the HF and VHF groups than in the C group at the end for 70 days. In Summary, the HF (45%) diet administered with fructose induced a higher similarity of metabolic and hormonal alterations associated with human obesity. PRACTICAL APPLICATIONS: High intake of lipids with sugary drinks has been associated with obesity and its comorbidities. Although a diet with 45% or 60% of lipids is considered hyperlipidic, they are different in their effects on eating behavior and also probably from a metabolic point of view. Common sense is that the reduction in intake of lipids is favorable to health. Our study shows that this is not wholly true, and this information contributes to the guidelines for the treatment of obesity. In addition, the scientific literature on the subject has shown the most diverse results and also the use of experimental models with few similarities with human obesity. Our findings can contribute as a good model of obesity initiated during childhood to investigate possible using nutritional strategies, or the adoption of ergogenic nutritional resources in future studies, for example.

Homocysteine level, body mass index and clinical correlates in Chinese Han patients with schizophrenia

Obesity is common comorbidity in patients with schizophrenia. Previous studies have reported that homocysteine (Hcy) is increased in schizophrenia. However, no study has reported the association between BMI and Hcy levels in schizophrenia. This cross-sectional naturalistic study aimed to evaluate the relationship between BMI, Hcy and clinical symptoms in Chinese Han patients with chronic schizophrenia. Clinical and anthropometric data as well as plasma Hcy level and glycolipid parameters were collected. Psychopathology was measured with the Positive and Negative Syndrome Scale (PANSS). Our results showed that compared with the low BMI group, the high BMI group had a higher PANSS general psychopathology subscore, higher levels of blood glucose, total cholesterol and high-density lipoprotein (HDL) cholesterol (all p < 0.05). Hcy levels were negatively associated with BMI in patients (p < 0.001). Hcy level, the PANSS general psychopathology subscale, total cholesterol and education (all p < 0.05) were the influencing factors of high BMI. Our study suggest that Hcy level may be associated with BMI in patients with schizophrenia. Moreover, patients with high BMI show more severe clinical symptoms and higher glucose and lipid levels.

Betaine ameliorates impaired steroidogenesis and apoptosis in mice granulosa cells induced by high glucose concentration

Betaine is a bioactive peptide whose beneficial effects on diabetes complications have been considered, previously. The present study aimed to investigate the possible protective effects of betaine against hyperglycemia-induced steroidogenesis impairment and apoptosis in mice granulosa cells. Ovarian granulosa cells were isolated from C57/BL6 mice and cultured in steroidogenesis medium (SM) containing 30 ng/ml FSH and 0.5 µM testosterone. The cells were cultured in SM containing low (5 mM) or high (30 mM) glucose concentrations for 24 h in the presence or absence of betaine (5 mM). At the end of the experiment, estradiol and progesterone were measured by ELISA in the culture medium. Expression of apoptosis and steroidogenesis associated genes and caspase-3 activity were determined by qRT-PCR and colorimetric assays, respectively. Exposure of mice granulosa cells to high glucose concentration inhibited the steroidogenesis by decreasing estradiol and progesterone secretion and downregulation of steroidogenesis-related genes including 3βHSD, Cyp11a1, Cyp19a1, and StAR. Betaine treatment could ameliorate the steroidogenesis impairment at molecular and biochemical levels. High glucose concentration also enhanced apoptosis in mice granulosa cells that were characterized by elevation of caspase-3 activity, upregulation of bax gene and downregulation of bcl2 gene. Betaine treatment could attenuate the apoptotic-related changes induced by high glucose concentration in granulosa cells. According to the results of the present study, betaine could ameliorate the adverse effects of hyperglycemia on the physiological function of ovarian granulosa cells. The results highlight the potential role of betaine for the intervention of ovarian dysfunction in diabetic patients. Abbreviations: AABA: Betaine-α-aminobutyric acid; AGEs: Advanced glycation end products; bax: bcl2 Associated X; bcl2: B-cell lymphoma 2; AMPK: AMP-activated protein kinase; BHMT: Betaine homocysteine methyltransferase; C/EBP: CCAAT-enhancer-binding proteins; Cyp11a1: Cholesterol side-chain cleavage cytochrome P450; Cyp19a1: Cytochrome P450 aromatase; DM: Diabetes mellitus; E2: Estradiol; ERS: Endoplasmic reticulum stress; GCs: Granulosa cells; GLUT: Glucose transporter; FSH: Follicle-stimulating hormone; 3βHSD: 3β-hydroxysteroid dehydrogenase; IL-1β: interleukin-1ß; LH: Luteinizing hormone; MDCK: Madin-Darby Canine Kidney cell; MT: Methionine synthase, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NLRP3: NLR Family Pyrin Domain Containing 3; NF-κB: Nuclear factor κB; P4: Progesterone; ROS: Reactive oxygen species; SGLT: Sodium dependent glucose transporter; SLC7A6: Solute Carrier Family 7 Member 6; StAR: Steroidogenic acute regulatory protein; STZ: Streptozotocin; Tumor necrosis factor α: TNF-α; TXNIP: Thioredoxin interacting protein.

Non-esterified fatty acids in the ovary: friends or foes?

A majority of common metabolic diseases can result in excessive lipolysis, leading to elevated levels of non-esterified fatty acids (NEFAs) in the body fluids. In females, increased NEFA levels in the follicular fluid markedly alter the functions of intrafollicular cells such as granulosa cells (GCs) and oocytes. Therefore, elevated levels of NEFAs have been suggested to be a significant player of subfertility in females of both human and economically important animal species such as cattle, buffalo, sheep, pig, chicken, and dog. However, the effects imposed by saturated and unsaturated fatty acids (SFAs and UFAs) on ovarian follicles are controversial. The present review emphasizes that SFAs induce apoptosis in granulosa and cumulus cells of ovarian follicles in different species. They further could adversely affect oocyte maturation and developmental competence. Many types of UFAs affect steroidogenesis and proliferation processes and could be detrimental for follicular cells, especially when at elevated concentrations. Interestingly, monounsaturated fatty acids (MUFAs) appear to contribute to the etiology of the polycystic ovarian syndrome (PCOS) as they were found to induce the transcription and translation of the androgenic transcription factor SOX9 while downregulating its estrogenic counterpart FOXL2 in GCs. Overall, this review presents our revised understanding of the effects of different fatty acids on the female reproductive success, which may allow other researchers and clinicians to investigate the mechanisms for treating metabolic stress-induced female infertility.

Effect of Myristica fragrans extract on total body composition in cafeteria diet induced obese rats

It is of interest to evaluate the effect of Myristica fragrans on body composition of cafeteria diet induced obese rats. Thirty rats (150-160g) grouped into 5 and each group contains 6 rats. Group-1 was normal control and 2-5 groups were fed with cafeteria diet for 15 weeks to induce obesity. From 16th week to 25th week test drugs were given as mentioned in the experimental protocol. Body weight, BMI, changes in body composition was measured by TOBEC, adipose tissue weights, organ weights, abdominal circumference were measured according to standard methods. After 70days of treatment with MFE 200mg/kg, 400mg/kg Body weight reduced by 9.29%, 12.87% respectively. BMI was also decreased. Abdominal circumference, total fat percentage, organ weights, was substantially reduced. At 400mg/kg of MFE has shown maximum potentiality when compared with 200mg/kg. Orlistat 50mg was used as standard drug. Tetrahydrofuran, flavonoids, saponins, present in Myristica fragrans has shown anti obesity activity. Our findings explain the potentiality of phytochemicals as a potent anti obesity agent, provide scientific evidence for its traditional use and suggest the possible mechanism of action.