Protective effect of lycopene on testicular toxicity induced by Benzo[a]pyrene intake in rats

Maternal exposure to phenanthrene induces testicular apoptosis and Sertoli cell dysfunction in F1 adult male mice: a histological and molecular study

OBJECTIVE

Phenanthrene, a polycyclic aromatic hydrocarbon, is found in abundance in environmental pollutants, food, and drinking water. This substance can accumulate in body tissues and exert harmful effects. Moreover, phenanthrene can cross the placental barrier, potentially impacting fetal development. We aimed to explore the impacts of maternal exposure to phenanthrene on testicular tissue and Sertoli cell function in F1 mice.

METHODS

Female rats with vaginal plugs were randomly assigned to one of three groups: control, sham, or phenanthrene. The control group received no intervention during pregnancy. In the sham and phenanthrene groups, corn oil and a phenanthrene solution, respectively, were administered via gavage once every 2 days. Offspring were separated by sex 21 days after birth. At 56 days postnatal, male F1 offspring were euthanized, and their testes were harvested for histological and molecular analyses.

RESULTS

Phenanthrene exposure was associated with a lower testicular weight and volume, a smaller diameter of the seminiferous tubules, and a relative thinning of the germinal epithelium. These changes were associated with increased cellular apoptosis, as shown by the upregulation of caspase 3 expression. Additionally, we observed an increase in vacuolization and residual bodies within the tissue. Conversely, the number of Sertoli cells and expression levels of Sox9, as well as the Ocln and Itgb1 genes, were found to be lowered.

CONCLUSION

Maternal exposure to phenanthrene impacts both germ cells and Sertoli cells, disrupting their function and leading to fertility disorders in male F1 offspring mice.

Heat-not-burn technology affects plasma testosterone levels and markers of inflammation, oxidative stress in the testes of rats

Introduction

Heating tobacco products (HTPs) are advanced electronic cigarette models. Classified by the FDA as a modified-risk tobacco product and can be used as part of efforts to quit smoking. Using heat-not-burn (HnB) technology, these devices heat tobacco avoiding complete combustion. Although the levels of toxicants in the mainstream are significantly lower than those observed in tobacco smoke, some recent studies have raised concerns about potential health risks associated with their use, particularly regarding their effects on male gonadal function, which remain largely unexplored.

Methods

Adult male Sprague-Dawley rats were exposed, whole body, 5 days/week for 4 weeks to HnB mainstream.

Results

The expression of the cell cycle regulators Bax/Bcl-2 ratio is not affected, along with no changes in p-38. On the other hand, an increase in oxidative stress markers, including those associated with DNA damage, was observed in exposed animals, along with the induction of NF-kB dependent pro-inflammatory mediators: TNF-α, IL-1β, IL-6 and COX-2. Furthermore, inactivation of key androgenic enzymes, such as 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase, together with decreased testosterone synthesis suggest a potential impairment of male gonadal function.

Discussion

The results indicate that animals exposed to HnB smoke show higher levels of oxidative stress markers, including those associated with DNA damage, as well as higher levels of pro-inflammatory cytokines. The impairment of some androgenic key enzymes and those related to the activity of seminiferous epithelium, together with the decrease in testosterone levels, suggest an impairment of gonadal function through the alteration of some cellular pathways typically associated with tobacco consumption.

Supplementing ageing male laying breeders with lycopene alleviates oxidative stress in testis and improves testosterone secretion

BACKGROUND

Reproductive performance is a crucial aspect of poultry production and is carefully controlled by endocrine, paracrine, and autocrine factors. This study aimed to investigate the effect of lycopene on testosterone synthesis in Leydig cells of laying breeder roosters, clarify the mechanism of lycopene improving Leydig cells function and promoting testosterone production, and explore the role of related signal transduction pathways in testosterone synthesis.

RESULTS

A total of 96 healthy 55-week-old breeding roosters were randomly assigned to one of five dietary treatments. They were provided with a corn-soybean meal-based diet containing different levels of lycopene: 0 mg/kg (control), 50 mg/kg, 100 mg/kg, or 200 mg/kg. The experiment lasted for 6 weeks. With the increase in lycopene levels, the testosterone content in the plasma was significantly higher than in the control group. Testicular Leydig cells were isolated and cultured from fresh testicular tissue of 45-wk-old to 60-wk-old breeding roosters. Various doses of lycopene were administered to Leydig cells, and subsequently, cells were collected for the detection of cell viability and testosterone content. The optimal concentration of lycopene to be added was determined, and changes in mRNA expression and protein levels of key proteins involved in testosterone synthesis were investigated. The results showed that lycopene treatment significantly increased testosterone secretion, mRNA expression, and protein levels of steroid-producing enzymes. Cells were collected to measure the activity of antioxidant enzymes, the mRNA transcription level of apoptotic factors, and the protein expression of apoptotic factors after treatment with lycopene. The results showed that lycopene significantly increased the activities of antioxidant enzymes, and the ability to inhibit oxygen radicals, and decreased the content of malondialdehyde. Apoptosis was inhibited by regulating the expression of apoptosis-inducing and anti-apoptosis factors. After that, the MAPK signaling pathway and downstream SF-1, Nrf2 gene, and protein expression levels were detected. The results showed that lycopene treatment significantly increased the gene and protein expression of JNK, SF-1, and Nrf2, and significantly decreased the gene and protein expression of p38.

CONCLUSIONS

Lycopene treatment could promote testosterone synthesis of testicular Leydig cells by activating MAPK-SF-1 (increasing steroid-producing enzyme level) and MAPK-Nrf2 pathways (resisting oxidative damage).

Effects of in utero benzo[a]pyrene exposure on the testis of rats during puberty and the protective effect of atorvastatin

Benzo[a]pyrene (BaP) is a contaminant that is generated in the environment through processes such as smoke, incomplete combustion of fossil fuels, vehicle exhaust emissions, entry into the body is through inhalation, and consumption of contaminated food. It is an omnipresent environmental pollutant with unavoidable exposure. BaP metabolites are observed in the male reproductive system, especially in the testes and epididymis of animals, and are responsible for reduced testicular and epididymal function. The protective effect of atorvastatin (ATV) on testicular damage was investigated previously. The aim of the present study was to investigate the protective effect of ATV on testicular toxicity induced by benzo[a]pyrene (BaP) during pregnancy in Wistar rats. This experimental laboratory study involved 40 adult rats, divided into seven groups and maintained under standard environmental conditions. The groups received different diets [control, corn oil, ATV (10 mg/kg), BaP (10 and 20 mg/kg), and ATV + BaP (10 and 20 mg/kg)] at gestation Days 7-16, orally. Male offspring were examined 10 weeks after birth. Testis and serum samples were collected, and testosterone level, malondialdehyde (MDA), and glutathione (GSH) were measured. Histological and immunohistochemical assays were performed under a light microscope. Statistical analysis was conducted using SPSS, with analysis of variance and Tukey tests to assess significant differences between groups. ATV significantly reduced MDA, a marker of lipid peroxidation and oxidative stress in rat testes following BaP administration. Treatment with ATV at doses of 10 mg/kg increased GSH levels, correcting disruptions in the antioxidant system caused by BaP. Testosterone concentration in rats treated with ATV and BaP substantially prevented the decrease induced by BaP. Histomorphometry revealed that ATV significantly prevented the detrimental effects of BaP on the thickness of spermatogenic epithelium and the diameter of seminiferous tubules. Under ATV treatment, testicular tissue histopathology improved, and spermatogenesis returned to a almost back to normal state. Caspase-3 expression decreased, and apoptosis activity in testicular tissue improved under ATV treatment, indicating a positive effect of ATV in reducing apoptotic damage caused by BaP. In conclusion, exposure to BaP can induce oxidative stress-related damage to testicular tissue, as evidenced by an increase in MDA levels, which ATV treatment can mitigate. Additionally, ATV enhances intracellular antioxidant GSH and protects the testes against BaP-induced damage while increasing testosterone levels, which are reduced due to exposure to BaP.

Lycopene protects against ionizing radiation-induced testicular damage by inhibition of apoptosis and mitochondrial dysfunction

Ionizing radiation (IR) is one of the key contributors that cause male infertility by disturbing spermatogenesis. Lycopene, a carotenoid with strong antioxidant properties, was shown to protect against oxidative damage induced by IR in several experimental models. The present study was designed to explore the possible protective effects of lycopene against IR-induced testicular damage in C57BL/6 mice. Mice were administered lycopene (20 mg/kg) by oral gavage for seven consecutive days prior to a single dose of whole-body X-ray irradiation (4 Gy, 1 Gy/min). We observed that lycopene remarkably augmented sperm motility and reduced sperm abnormalities in mice following IR exposure. Histopathological analyses also revealed that lycopene ameliorated the structural damage of seminiferous tubules and enhanced the regeneration of seminiferous epithelium following IR stress. Moreover, lycopene attenuated IR-induced oxidative stress, as evidenced by a decreasing lipid peroxidation level and an increase in the antioxidant enzyme superoxide dismutase activity. In addition, lycopene reduced the γH2AX expression and the number of TUNEL-positive cells in the germinal epithelium, as well as restoring the imbalance of Bax/Bcl-2 expression induced by IR exposure. Furthermore, lycopene prevented mitochondrial membrane potential depolarization and ATP reduction and preserved the activities of mitochondrial complexes I-IV in the testes of mice after exposure to IR. Lycopene also improved mitochondrial biogenesis in testes of mice exposed to IR, presenting as restored expressions of PGC-1α, Nrf1, and Tfam. Taken together, our results suggest that lycopene alleviates IR-induced testicular damage, and the underlying mechanism involves at least in part the inhibition of the mitochondrial apoptotic pathway and the maintenance of mitochondrial respiration and biogenesis. The beneficial effect of lycopene highlights the therapeutic potential of this plant-derived antioxidant against impaired spermatogenesis and male infertility induced by IR.

Lycopene ameliorates aflatoxin B1-induced testicular lesion by attenuating oxidative stress and mitochondrial damage with Nrf2 activation in mice

Aflatoxin B₁ (AFB₁) is an extremely hazardous and unavoidable pollutant for cereals and feedstuff. AFB₁ can cause testicular lesion, and how to alleviate its testicular toxicity has received much attention in recent years. Lycopene (LYC), a foodborne nutrient derived from red fruits and vegetables, has protective effects against sperm abnormality and testicular lesions. To confirm the beneficial effects and mechanisms of LYC on AFB₁-induced testicular lesion, 48 male mice were exposed to 0.75 mg/kg AFB₁ or/and 5 mg/kg LYC for consecutive 30 days. Results demonstrated the LYC significantly restored the lesions of testicular microstructure and ultrastructure, and sperm abnormalities in AFB₁-exposed mice. Furthermore, LYC effectively attenuated AFB₁-induced oxidative stress and mitochondrial damage, including ameliorative mitochondrial structural, and elevated mitochondrial biogenesis for maintaining mitochondrial function. Meanwhile, LYC resisted AFB₁-induced mitochondrial-dependent apoptosis. In addition, LYC promoted nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, and upregulated the Nrf2 signaling pathway. Collectively, our findings demonstrate LYC ameliorates AFB₁-induced testicular lesion by attenuating oxidative stress and mitochondrial damage, which is related to the activation of Nrf2.

Role of ROS/JAK2/STAT3 signaling pathway in di-n-butyl phthalate-induced testosterone synthesis inhibition and antagonism of lycopene

Di-n-butyl phthalate (DBP) causes adverse effects on male reproduction, especially testosterone synthesis inhibition. However, the specific mechanism of DBP-induced testosterone synthesis inhibition and its effective intervention measures of prevention and treatment are scarce presently. Lycopene (LYC) plays beneficial roles in male infertility because of its antioxidant activity. Nevertheless, it is unclear whether LYC could prevent DBP-induced male reproductive toxicity. By in vitro and in vivo investigations, this study demonstrated that DBP activated ROS/JAK2/STAT3 signaling pathway, promoted mitophagy and apoptosis, which in turn inhibited testosterone synthesis. Additionally, another major finding was that LYC supplement could reverse the above change, presenting as the restraint of ROS/JAK2/STAT3 signaling pathway, reduction of mitophagy and apoptosis, and improvement of testosterone synthesis. Our study facilitates deeper understandings of the mechanism in DBP-induced testosterone synthesis inhibition, and identifies LYC as the effective prevention and control strategies for DBP poisoning.

Comparative Potential of Zinc Sulfate, L-Carnitine, Lycopene, and Coenzyme Q10 on Cadmium-Induced Male Infertility

The human exposure to toxic chemicals and heavy metals is one of the main predisposing factors contributing to male infertility. Acute exposure to cadmium chloride results in testicular damage and infertility. The purpose of the present study was to investigate and compare the curative effect of coenzyme Q10 (CoQ10), lycopene, L-carnitine (LC), and zinc sulfate against the cadmium-induced infertility in male Wistar rats. Cadmium chloride (0.4 mg/kg/day) was orally administered to rats for three consecutive days. Then, oral administration of different treatments (i.e., LC 100 mg/kg, CoQ10 20 mg/kg, lycopene 4 mg/kg, zinc sulfate 6 mg/kg, and a combination LC-CoQ10 at 500/50 mg/kg) was carried out for 30 days. The impact of different treatments on semen parameters, such as sperm count and motility, testicular antioxidants, and serum testosterone, was determined. Furthermore, the morphology of epididymis sperms and histopathology of rat testes were also assessed. Cadmium exposure decreased the sperm count, progressive sperm motility, testosterone, superoxide dismutase (SOD), and catalase and reduced glutathione (GSH). It also caused banana sperm tail, bent sperm head, vacuolization of seminiferous tubules, and oligospermia in rat testes. All treatments with nutraceuticals improved sperm count, sperm morphology, serum testosterone, vacuolization of seminiferous tubules, and oligospermia in diseased rats. Treatment with lycopene, LC, and LC-CoQ10 improved progressive sperm motility and other parameters and increased SOD, GSH, and CAT in the rat testes. CoQ10 also increased SOD activity in rat testes' tissue homogenates. It is concluded from the current study that all nutraceuticals partially improved reproductive toxicity of cadmium. The administration of lycopene and a high-dose combination of LC-CoQ10 were more efficacious in treating cadmium-induced infertility than other treatments. Treatment of cadmium-exposed rats with lycopene, LC, CoQ10, and LC-CoQ10 improved sperm count and motility through reduction of testicular oxidative stress and improving serum testosterone.

Benzo[a]pyrene exposure promotes RIP1-mediated necroptotic death of osteocytes and the JNK/IL-18 pathway activation via generation of reactive oxygen species

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) of environmental pollutants, readily produced during the processing of petroleum and fatty foods. BaP exposure can cause skeletal deformities. However, whether BaP affects osteocytes, making up over 95% of all the bone cells, remains unknown. This study aimed to investigate the effect of BaP on osteocytes in vivo and in vitro, as well as explore the underlying mechanisms. The in vivo data showed that BaP (50mg/kg) exposure for 12 weeks could cause bone destruction, and increase osteocytes death in mouse cortical femur. Our in vitro results revealed that BaP (25-100 μmol/L) exposure inhibited cell viability of MLO-Y4 cells, and resulted in cell death in a dose-dependent manner. Furthermore, BaP exposure significantly triggered necroptosis of MLO-Y4 cells, as indicated by increased propidium iodide (PI)-positive cells and up-regulation of necroptosis-related protein expressions of receptor-interacting protein kinase 1 (RIP1), RIP3, and mixed lineage kinase domain-like protein (MLKL). This necrotic effect was reversed by the RIP1 inhibitor necrostatin-1 (Nec-1). Simultaneously, BaP activated the downstream c-Jun N-terminal kinase (JNK)/ interleukin (IL)-18 signaling pathway, which was suppressed after the JNK inhibitor SP600125 or Nec-1 treatment. In addition, BaP exposure promoted the production of intracellular reactive oxygen species (ROS), mitochondrial ROS (mtROS), and elevated malondialdehyde (MDA) levels; while BaP decreased superoxide dismutase (SOD) activity and antioxidant enzymes including nuclear factor E₂-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels, leading to oxidative damage. The ROS scavenger N-acetylcysteine (NAC) inhibited this necroptotic death and the JNK/IL-18 pathway activation. Collectively, BaP exposure may cause RIP1-mediated necroptotic death of osteocytes and activate the JNK/IL-18 pathway via ROS generation.

Lycopene Alleviates Titanium Dioxide Nanoparticle-Induced Testicular Toxicity by Inhibiting Oxidative Stress and Apoptosis in Mice

PURPOSE

The research was carried out to investigate the possible ameliorative effect of lycopene on TiO₂ NPs-induced male reproductive toxicity and explore the possible mechanism.

METHODS

Ninety-six healthy male Institute of Cancer Research (ICR) mice were equally divided into eight groups (control group, 50 mg/kg TiO₂ NPs group, 5 mg/kg LYC group, 20 mg/kg LYC group, 40 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 5 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 20 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 40 mg/kg LYC group), and the mice were treated by intragastric administration every day for 30 days in this research. Sperm parameters, testicular histopathology, oxidant and antioxidant enzymes, and cell apoptosis-related protein expression in the testicular tissue were analyzed.

RESULTS

The results showed that TiO₂ NPs exposure significantly decreased sperm count and motility, and TiO₂ NPs also increased sperm malformation in the epididymis; these characteristics were improved when co-administration with LYC. Testicular histopathological lesions like disorder of germ cells arrange, detachment, atrophy, and vacuolization were observed after TiO₂ NPs exposure, and these abnormalities were effectively ameliorated by co-administration with LYC. Oxidative stress was induced by TiO₂ NPs exposure as evidenced by increased the level of MDA and decreased the activity of SOD as well as the level of anti-O₂^-, and these alterations were effectively prevented by co-administration with LYC. LYC also alleviated TiO₂ NPs-induced germ cell apoptosis by inhibiting mitochondrial apoptotic pathway, as shown by the upregulation of Bcl-2, the downregulation of Bax, Cleaved Caspase 3, and Cleaved Caspase 9.

CONCLUSION

LYC could ameliorate TiO₂ NPs-induced testicular damage via inhibiting oxidative stress and apoptosis, which could be used to alleviate the testicular toxicity associated with TiO₂ NPs intake.

Testicular toxicity of cisplatin in rats: ameliorative effect of lycopene and N-acetylcysteine

Lycopene (LP) and N-acetylcysteine (NAC) protective effects were assessed for testicular toxicity mediated by cisplatin (CP) in rats. Forty-nine rats were divided into 7 groups (n = 7); these groups included the control group (saline, PO), LP (10 mg/kg, PO), NAC (150 mg/kg, PO), CP (7.5 mg/kg, IP) on the 27th day of the study, LP + CP, NAC+CP, and LP + NAC + CP. Serum levels of testosterone were decreased following CP injection. Malondialdehyde (MDA) has been increased with considerable glutathione (GSH), and dismutase superoxide (SOD) and catalase (CAT) decline in the testis tissues after CP injection. CP caused severe alterations in testicular tissues and elevated caspase-3 expression. Besides that, LP and/or NAC administration improved CP-induced testicular toxicity and apoptosis, probably via their antioxidant properties.

N-acetylcysteine alleviates pulmonary inflammatory response during benzo[a]pyrene-evoked acute lung injury

Benzo[a]pyrene (BaP), a representative polycyclic aromatic hydrocarbon, exists widely in automobile emissions and polluted atmosphere. The current study aimed to describe pulmonary inflammation during BaP-induced acute lung injury (ALI). All mice except controls were intratracheally instilled with a single dose of BaP (90 μg per mouse). The alveolar structure was damaged, accompanied by numerous inflammatory cell infiltration around pulmonary interstitium and small airway. Airway wall area and mean linear intercept were reduced in BaP-exposed mouse lungs. By contrast, airway wall thickness and destructive index were elevated in BaP-exposed mouse lungs. Several inflammatory genes, such as Tnf-α, Il-1β, Il-6, Mip-2, Kc, and Mcp-1, were upregulated in mouse lungs. Phosphorylated IκBα was elevated in BaP-exposed mouse lungs. Nuclear translocation of NF-κB p65 and p50 was accordingly observed in BaP-exposed mouse lungs. Several molecules of the MAPK pathway, including JNK, ERK1/2, and p38, were activated in mouse lungs. Of interest, pretreatment with N-acetylcysteine (NAC), an antioxidant, alleviated BaP-induced ALI. Moreover, NAC attenuated BaP-induced inflammatory cell infiltration in mouse lungs and inflammatory gene upregulation in A549 cells. In addition, NAC attenuated BaP-induced NF-κB activation in A549 cells and mouse lungs. These results suggest that NAC alleviates pulmonary inflammatory response during BaP-evoked ALI.

Lycopene prevents DEHP-induced testicular endoplasmic reticulum stress via regulating nuclear xenobiotic receptors and unfolded protein response in mice

Lycopene (LYC) is a potent antioxidant synthesized by red vegetables or plants. Di-2-ethylhexyl phthalate (DEHP) is frequently detected in diverse agricultural environments and considered as a reproductive toxicant. The present research was designed to assess the potential mechanisms of DEHP-induced testicular toxicity and the treatment efficacy of LYC. In this study, after the oral administration of LYC at the dose of 5 mg per kg b.w. per day, mice were given 500 or 1000 mg per kg b.w. per day of DEHP. This research suggested that LYC prevented the DEHP-induced disorder at the levels of activity and content of CYP450 enzymes. LYC attenuated DEHP-caused enhancement in nuclear xenobiotic receptors (NXRs) and the phase I metabolizing enzymes (CYP1, CYP2, CYP3, etc.) levels. Furthermore, endoplasmic reticulum (ER) stress was induced by DEHP and triggered unfolded protein response (UPR). Interestingly, LYC could effectively ameliorate these "hit". The present study suggested that LYC prevents DEHP-induced ER stress in testis via regulating NXRs and UPRER.

Long-term exposure to environmental levels of phenanthrene disrupts spermatogenesis in male mice

Phenanthrene (Phe) is a tricyclic polycyclic aromatic hydrocarbon with high bioavailability under natural exposure. However, there are few studies on the reproductive toxicity of Phe in mammals. In this study, male Kunming mice were gavaged once every two days with Phe (5, 50, and 500 ng/kg) for 28 weeks. The accumulation levels of Phe in the testis were dose-dependently increased. Histopathological staining showed that Phe exposure reduced the number of spermatogonia, sperm and Sertoli cells. The percentage of testicular apoptotic cells was significantly increased, which was further verified by the upregulated BAX protein. The expression of the GDNF/PI3K/AKT signaling pathway was downregulated, which might suppress the self-renewal and differentiation of spermatogonial stem cells. Meanwhile, Phe exposure inhibited the expression of Sertoli cell markers (Fshr, WT1, Sox9) and the Leydig cell marker Cyp11a1, indicating damage to the function of Sertoli cells and Leydig cells. Serum estrogen and testicular estrogen receptor alpha were significantly upregulated, while androgen receptor expression was downregulated. These alterations might be responsible for impaired spermatogenesis. This study provides new insights for evaluating the reproductive toxicity and potential mechanisms of Phe in mammals.

Recent trends and advances in the epidemiology, synergism, and delivery system of lycopene as an anti-cancer agent

Dietary interventions are key nutritional strategies to prevent, improve, and prolong the survival of cancer patients. Lycopene, one of the strongest natural antioxidants, and its biologically active metabolites, have shown significant potential to prevent a variety of cancers, including prostate, breast, and stomach cancers, making it a promising anti-cancer agent. We review the potential regulatory mechanisms and epidemiological evidences of lycopene and its metabolites to delay the progression of cancers at different developmental stages. Recent studies have revealed that lycopene and its metabolites mediate multiple molecular mechanisms in cancer treatment such as redox homeostasis, selective anti-proliferation, apoptosis, anti-angiogenesis, tumour microenvironment regulation, and anti-metastasis and anti-invasion. Gut microbes and cholesterol metabolism are also the potential regulation targets of lycopene and its metabolites. As a dietary supplement, the synergistic interaction of lycopene with other drugs and nutrients is highlighted especially due to its binding activity with other nutrients in the diet found central to the fight against cancer. Furthermore, the application of several of novel lycopene delivery carriers are on the rise including nanoemulsions, nanostructured liposomes, and polymer nanoparticles for cancer prevention as discussed in this review with future needed development. Moreover, the synergistic mechanism between lycopene and other nutrients or drugs and novel delivery systems of lycopene should now be deeply investigated to improve its clinical application in cancer intervention in the future.

Effect of mitochondrial quality control on the lycopene antagonizing DEHP-induced mitophagy in spermatogenic cells

Di(2-ethylhexyl) phthalate (DEHP) is a widespread environmental contaminant, which is mainly used as a plasticizer to improve the flexibility of products; however, its extensive use causes male reproductive damage. Lycopene (LYC) has a protective effect on male reproductive toxicity. Nevertheless, the underlying role of LYC in DEHP-induced spermatogenic cell damage remains unclear. Our study aimed to investigate the role of LYC in DEHP-induced spermatogenic cell damage and its underlying mechanism. Male ICR mice were treated with LYC (5 mg kg-1) and/or DEHP (500 mg kg-1 or 1000 mg kg-1) for 28 days. The results showed that LYC alleviated the DEHP-induced decrease in mitochondria volume density and mitochondrial membrane potential (ΔΨm). Subsequently, LYC prevented the DEHP-induced PGC-1α-mediated reduction in mitochondrial biogenesis in spermatogenic cells. LYC exhibited a potential preventive effect against DEHP-induced mitophagy caused by mitochondrial dynamics disorder in the spermatogenic cells. Meanwhile, LYC relieved DEHP-induced mitochondrial stress in the spermatogenic cells by activating UPRmt. These results proved that mitochondrial quality control may be related to the beneficial role of LYC in preventing DEHP-induced mitophagy in spermatogenic cells. This study provides new evidence of mitochondrial quality control as a target for LYC treatment, which can prevent DEHP-induced toxicity.

Carotenoid absorption in rats fed with vacuum-fried papaya chips depends on processed food microstructure associated with saturated and unsaturated oils

Many studies indicate that food matrix microstructure and type of dietary oil or fat play a key role in carotenoid absorption. Therefore, this work was designed to highlight the relationship between processed food microstructure and carotenoid absorption. This study aimed to evaluate the consumption of a carotenoid-rich fruit snack on lipid profile, glycemia and especially on carotenoid absorption/bioconversion in Wistar rats. Animals were fed with mixtures based on vacuum-fried papaya chips with either soy oil (PC-S) or palm oil (PC-P) during 7 days, receiving 0.29 mg lycopene/kg/day and 0.35 mg total carotenoids/kg/day. Lycopene and retinoids were analyzed in plasma and liver of rats by HPLC-DAD. Results showed that the consumption of mixtures based on papaya chips did not affect the lipid profile or glycemia in rat plasma, regardless the type of oil. Wide-field and confocal microscopy analyses of food matrix helped to understand why lycopene accumulation in the liver was higher (p < 0.05) in rats fed with PC-P (0.442 µg/g liver) than in those fed with PC-S (0.291 µg/g liver). A better dissolution of crystalloid lycopene was found in PC-P. Conversely, a higher bioconversion of provitamin A carotenoids was observed for soy products. The effect of type of oil was underlined by epifluorescence microscopy of papaya mixtures showing homogeneous and small lipid droplets for soy products. These results showed that PC-S could be recommanded as a healthy snack, being a source of provitamin A carotenoids and bioavailable lycopene in a diversified diet.

Exposure to benzo(a)pyrene from juvenile period to peripubertal impairs male reproductive parameters in adult rats

Benzo(a)pyrene (BaP) is a persistent organic pollutant and endocrine disruptor that can compromise the steroidogenesis process by interacting with the StAR protein, causing adverse effects on male reproduction. However, consequences of prepubertal BaP exposure and its impacts on adult life are yet unknown. This study investigated the effects of BaP exposure from the juvenile period to peripubertal on reproductive parameters in adult male rats. Males were exposed to 0; 0.1; 1 or 10 μg/kg/day of BaP from post-natal (PND) 23 to PND 53 (by gavage). The lowest dose of BaP was able to compromise the male copulatory behavior, as evidenced by the delay in the first mount, intromission and ejaculation. Furthermore, BaP-treated groups showed lower sperm quality (disrupted motility and morphology) and quantity, reduced relative weights of the thyroid and seminal gland. Serum testosterone levels and the Leydig cells nuclei volume were decreased by BaP exposure whereas the StAR expression was increased. Histopathological changes in the testis also were detected in the males exposed to BaP. These results showed that prepubertal BaP-exposure adversely influenced the male reproductive system in the adult life, indicating that a comprehensive risk assessment of BaP-exposure on prepubertal period is necessary.

Lead-induced cardiomyocytes apoptosis by inhibiting gap junction intercellular communication via autophagy activation

Lead (Pb) is one of the most common heavy metal contaminants in the environment. Pb can cause pathophysiological changes in several organ systems, including the cardiovascular system, but the molecular mechanism remains elusive. The study aimed to study the effects of Pb on Gap junction intercellular communication (GJIC) and its role in Pb-induced apoptosis. The present study aims to determine whether Pb-induced autophagy promotes apoptosis of rat cardiac myocytes (H9c2 cells) by downregulating GJIC using CCK-8 Kit, scrape loading/dye transfer assay, Annexin V/PI assays, Western blot analysis and double-immunofluorescence experiments. The results showed that Pb elicited cytotoxicity in a time- and concentration-dependent manner and led to increased apoptosis in a concentration-dependent manner in H9c2 cells. Pb also reduced GJIC in H9c2 cells in a concentration-dependent manner through the downregulation of connexin (Cx) 43. Inhibition of gap junctions by gap junction blocker carbenoxolone disodium (CBX) resulted in increased apoptosis. Furthermore, Pb increased autophagy in a concentration-dependent manner in H9c2 cells, decreasing the distribution of Cx43 on the cell membrane, and targeted Cx43 to autophagosome via light chain 3 (LC3). However, autophagy inhibitor 3-Methyladenine (3-MA) can slow down the downregulation of Cx43 induced by Pb in H9c2 cells. In conclusion, our results provide evidence that Pb-decreased GJIC promotes apoptosis in cardiomyocytes. This is probably because of the fact that Pb-induced autophagy exacerbates GJIC inhibition and downregulation of Cx43.