The effects of high-fructose corn syrup consumption on testis physiopathology-The ameliorative role of melatonin

Ameliorative effects of Myrtus communis L. extract involving the inhibition of oxidative stress on high fat diet-induced testis damage in rats

The possible protective effects of Myrtus communis L. (MC) extract on a high fat diet (HFD)-induced testicular injury in a rat model were investigated using histological and biochemical methods. Wistar albino rats were divided into three groups: a standard diet control group; a HFD group; and an HFD+MC group. The HFD and HFD+MC groups were fed with a HFD for 16 weeks. MC extract (100 mg/kg) was given orally five days a week to the rats in the HFD+MC group during the last four weeks of the experiment. Leptin, triglyceride, high-density lipoproteins, cholesterol, estrogen, testosterone, LH and FSH were analyzed in blood serum. Sperm parameters were evaluated from the epididymis. Testicular morphology, proliferative, apoptotic and NADPH oxidase-2 (NOX2)-positive cells were evaluated histologically. Testicular oxidative stress parameters were analyzed biochemically. In the HFD group, lipid and hormone profiles were changed, abnormal spermatozoa, degenerated seminiferous tubules with apoptotic and NOX2-positive cells were increased in number, and sperm motility and germinal proliferative cells decreased compared to the control group. Moreover, testicular malondialdehyde, 8-hydroxy-2-deoxyguanosine and myeloperoxidase levels increased, whereas glutathione and superoxide dismutase levels decreased in the HFD group compared to the control group. All these histological and biochemical features were ameliorated by MC treatment of HFD-fed rats. In conclusion, HFD caused alterations in sperm parameters and testicular morphology by increasing oxidative damage and apoptosis. MC extract may have potential protective effects by inhibiting oxidative damage.

Ameliorative impacts of propolis against testicular toxicity promoted by doxorubicin

Background and Aim

Doxorubicin (DOX) is often used as a chemotherapeutic agent, although it may damage testicular functions. This study was designed to investigate the protective effects of propolis on testicular histological changes, semen parameters, and testosterone concentrations as a means of protecting against testicular damage caused by DOX chemotherapy.

Materials and Methods

Forty-eight male Wistar rats were divided into four groups with 12 animals per group. The first group served as the control. Rats in the second group were administered 4 mg/kg DOX. The third group was administered 4 mg/kg of DOX and 30 mg/kg b.w. propolis. The fourth group was orally dosed daily with 30 mg/kg b.w. propolis.

Results

DOX treatment resulted in a significantly decreased weight gain (WG) rate compared with the control, whereas DOX + propolis resulted in improved WG and returned to the normal range. Testosterone levels were comparable among the experimental groups, with a significant increase in the propolis-treated group. In addition, DOX-treated groups exhibited a remarkable depletion in sperm counts, motility, and viability compared to the other groups.

Conclusion

Most of the histological and hormonal changes resulting from the toxicity of DOX returned to almost normal after treatment of rats with the aqueous extract of propolis, indicating that propolis ameliorated the effects of DOX poisoning on testicular function in male rats.

The impact of dietary fructose on gut permeability, microbiota, abdominal adiposity, insulin signaling and reproductive function

The excessive intake of fructose in the regular human diet could be related to global increases in metabolic disorders. Sugar-sweetened soft drinks, mostly consumed by children, adolescents, and young adults, are the main source of added fructose. Dietary high-fructose can increase intestinal permeability and circulatory endotoxin by changing the gut barrier function and microbial composition. Excess fructose transports to the liver and then triggers inflammation as well as de novo lipogenesis leading to hepatic steatosis. Fructose also induces fat deposition in adipose tissue by stimulating the expression of lipogenic genes, thus causing abdominal adiposity. Activation of the inflammatory pathway by fructose in target tissues is thought to contribute to the suppression of the insulin signaling pathway producing systemic insulin resistance. Moreover, there is some evidence that high intake of fructose negatively affects both male and female reproductive systems and may lead to infertility. This review addresses dietary high-fructose-induced deteriorations that are obvious, especially in gut permeability, microbiota, abdominal fat accumulation, insulin signaling, and reproductive function. The recognition of the detrimental effects of fructose and the development of relevant new public health policies are necessary in order to prevent diet-related metabolic disorders.

Protective effects of melatonin against oxidative stress induced by metabolic disorders in the male reproductive system: a systematic review and meta-analysis of rodent models

Background

Male infertility is a multifaceted issue that has gained scientific interest due to its increasing rate. Studies have demonstrated that oxidative stress is involved in male infertility development. Furthermore, metabolic disorders, including obesity, diabetes, hypo- and hyperthyroidism, are risk factors for male infertility, and oxidative stress is believed to contribute to this association. Melatonin, functioning as an oxidative scavenger, may represent a promising therapeutic approach for the prevention and treatment of metabolic disorder-associated male infertility.

Material and methods

We systematically searched three online databases (PubMed, Scopus, and Web of Science) for studies that evaluated the effects of melatonin therapy on metabolic disorders-induce infertility in male rodents. The favorable outcomes were histopathological parameters of testicular tissue, reproductive hormones, and markers of oxidative stress. Then, meta-analyses were done for each outcome. The results are reported as standardized mean difference (Cohen's d) and 95% confidence interval.

Results

24 studies with 31 outcomes were included. Rats and mice were the subjects. Studies have employed obesity, diabetes, hypothyroidism, hyperthyroidism, hyperlipidemia, and food deprivation as metabolic disorders. To induce these disorders, a high-fat diet, high-fructose diet, leptin, streptozotocin, alloxan, carbimazole, and levothyroxine were used. The outcomes included histopathologic characteristics (abnormal sperm morphology, apoptotic cells, apoptotic index, Johnsen's testicular biopsy score, seminiferous epithelial height, tubular basement membrane thickness, tubular diameter, sperm count, and motility), weight-related measurements (absolute epididymis, testis, and body weight, body weight gain, epididymal adipose tissue weight, and relative testis to body weight), hormonal characteristics (androgen receptor expression, serum FSH, LH, and testosterone level), markers of oxidative stress (tissue and serum GPx and MDA activity, tissue CAT, GSH, and SOD activity), and exploratory outcomes (serum HDL, LDL, total cholesterol, triglyceride, and blood glucose level). The overall pooled effect sizes were statistically significant for all histopathological characteristics and some markers of oxidative stress.

Conclusions

Melatonin can reduce damage to male rodents' gonadal tissue and improve sperm count, motility, and morphology in metabolic diseases. Future clinical studies and randomized controlled trials are needed to evaluate the safety and effectiveness of melatonin for male infertility in patients with metabolic diseases.

Apocynin Ameliorates Testicular Toxicity in High-Fat Diet-Fed Rats By Regulating Oxidative Stress

Objective: The purpose of this study was to examine the effects of apocynin (APC), an inhibitor of NADPH oxidase (NOX), on high-fat diet (HF)-induced testis cytotoxicity. Methods: Wistar albino rats were divided into three groups as control, HF and HF+APC groups. Rats in HF and HF+APC groups were fed using HF for 16 weeks and in the last four weeks of this period vehicle solution or APC (25 mg/kg) was administered orally five days a week, respectively. Control group was fed with standart lab chow for 16 weeks. Cholesterol, triglyceride, high-density lipoproteins, leptin, estrogen, testosterone, LH and FSH were estimated in blood serum. Sperm parameters were analysed from the epididymis. Testicular malondialdehyde, 8‐hydroxy‐2‐deoxyguanosine, glutathione, superoxide dismutase and myeloperoxidase levels were estimated biochemically. Testicular morphology, proliferative, apoptotic and NOX2-positive cells were analysed histologically. HF-induced obesity caused significant alterations in serum lipid and hormone profiles. Testicular malondialdehyde, 8‐hydroxy‐2‐deoxyguanosine, and myeloperoxidase levels increased, glutathione and superoxide dismutase levels decreased in this group. Moreover, altered sperm parameters, increased degenerated seminiferous tubules, apoptotic and NOX2- positive cells and decreased proliferative cells were observed in the HF group. All these biochemical and histological alterations improved in the HF+APC group. Conclusion: HF-induced obesity causes altreations in lipid values, sperm parameters and testicular morphology by increasing oxidative stress through NOX2 activity. Apocynin might prevent testis damage via regulating oxidant/antioxidant balance.

Effects of high fructose corn syrup on intestinal microbiota structure and obesity in mice

High fructose corn syrup (HFCS)-associated health problems have raised concerns. We investigated the effects of HFCS-containing drinking water on body fat, intestinal microbiota structure of mice, and the relationships between them. HFCS drinking water significantly increased body fat content and altered the intestinal microbiome. The Christensenellaceae R-7 group negatively correlated with body weight, perirenal fat, epididymal fat, and liver fat percentage.

Dietary high-fructose reduces barrier proteins and activates mitogenic signalling in the testis of a rat model: Regulatory effects of kefir supplementation

There are limited data on the influence of fructose rich diet on the male reproductive system. Kefir may have health beneficial effects, but its mechanism of action remains mostly unclear. Herein, we investigated the impact of dietary high fructose on tight junction proteins and mitogenic pathways in rat testis as well as their modulation by kefir supplementation. Twenty-two male Wistar rats (4 weeks old) were divided into the following three groups: Control; Fructose; Fructose + Kefir. Fructose was added to drinking water at concentration of 20% and administered to the rats for 15 weeks and kefir was supplemented by gavage once a day during final 6 weeks. Dietary fructose-induced testicular degeneration was associated with the downregulation of the blood-testis barrier proteins, claudin-11 and N-cadherin as well as SIRT1 expression in testicular tissue of rats. However, p38MAPK, p-p38MAPK and p-ERK1/2 levels were increased in testis of fructose-fed rats. Interestingly, JNK1 and p-JNK1 protein levels were decreased following this dietary intervention. Raf1, ERK1/2, and caspase 3 and TUNEL staining of the testis reveal the activation of apoptosis due to fructose intake. Kefir supplementation markedly promoted the expression of claudin-11, SIRT1, JNK1 and p-JNK1 but suppressed testicular mitogenic and apoptotic factors in fructose-fed rats.

Reproductive disorders in male rats induced by high-fructose consumption from juvenile age to puberty

There is compelling evidence that a hypercaloric, high-fructose diet can cause metabolic syndrome (MetS) and a whole range of other metabolic changes. In the context of androgen deficiency, MetS in boys merits special attention, but the effects of fructose-rich diet in youth on future male reproductive function are still poorly evidenced. The aim of this study was to address this issue and analyse the effects of high-fructose intake starting from weaning to puberty (postnatal day 23 up to 83) on the reproductive function of male rats. For this purpose juvenile male Wistar rats were divided in two groups: control and the group receiving 10 % fructose solution instead of drinking water. Reproductive function was evaluated in terms of fertility, sperm count, testes/epididymis morphology, and serum sex hormones. The fructose-treated group showed a decrease in testosterone and twofold increase in luteinising and follicle-stimulating hormone levels in the serum. This was accompanied with lower testis/epididymis weights, sperm count, and changed testis/epididymis morphology. Their fertility remained unchanged, but the fertility of females mating with these males diminished. In addition, pre-implantation and post-implantation embryonic death rate rose in these females. Our results have confirmed that high fructose consumption from early age until puberty can impair the reproductive function of male rats, and call for further animal and epidemiological investigation.

Daily and seasonal mitochondrial protection: Unraveling common possible mechanisms involving vitamin D and melatonin

From an evolutionary point of view, vitamin D and melatonin appeared very early and share functions related to defense mechanisms. In the current clinical setting, vitamin D is exclusively associated with phosphocalcic metabolism. Meanwhile, melatonin has chronobiological effects and influences the sleep-wake cycle. Scientific evidence, however, has identified new actions of both molecules in different physiological and pathological settings. The biosynthetic pathways of vitamin D and melatonin are inversely related relative to sun exposure. A deficiency of these molecules has been associated with the pathogenesis of cardiovascular diseases, including arterial hypertension, neurodegenerative diseases, sleep disorders, kidney diseases, cancer, psychiatric disorders, bone diseases, metabolic syndrome, and diabetes, among others. During aging, the intake and cutaneous synthesis of vitamin D, as well as the endogenous synthesis of melatonin are remarkably depleted, therefore, producing a state characterized by an increase of oxidative stress, inflammation, and mitochondrial dysfunction. Both molecules are involved in the homeostatic functioning of the mitochondria. Given the presence of specific receptors in the organelle, the antagonism of the renin-angiotensin-aldosterone system (RAAS), the decrease of reactive species of oxygen (ROS), in conjunction with modifications in autophagy and apoptosis, anti-inflammatory properties inter alia, mitochondria emerge as the final common target for melatonin and vitamin D. The primary purpose of this review is to elucidate the common molecular mechanisms by which vitamin D and melatonin might share a synergistic effect in the protection of proper mitochondrial functioning.

Bee glue (propolis) improves reproductive organs, sperm quality and histological changes and antioxidant parameters of testis tissues in rats exposed to excess copper

This study was designed to determine the effects of propolis on the sperm quality, antioxidant and histological parameters in the testicular tissues of male Sprague Dawley rats exposed to excessive copper (Cu). In this aim, 24 rats were randomly divided into four groups as follows: the control, Cu, Propolis and Cu+Propolis. When compared to control group, Cu administration significantly decreased sperm motility and concentration, increased total abnormal sperm rate. It caused a significant induction the malondialdehyde (MDA), and reduction the superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) in testicular tissues. Also, it caused loss, disorganisation and vacuolation of the germinal epithelium, oedema of the interstitial tissues, proliferation of the interstitial cells, spilled immature spermatogenic cells in the lumen of some seminiferous tubules. A large number of active caspase-3-positive stained apoptotic cells and a significant decrease in Johnsen's testicular score were determined. However, significant ameliorations were observed in all sperm characteristics, MDA, SOD, CAT, GSH, seminiferous tubules, number of apoptotic cells and Johnsen's testicular score in Cu+Propolis group. Our results showed that oral supplementation of propolis had curative effect on the sperm quality, antioxidant and histological parameters in the testicular tissues of male Sprague Dawley rats exposed to Cu.