Can lifelong endurance exercise improve ageing through beneficial effects on circadian timing function, muscular performance and health status in men? Protocol for a comparative cross-sectional study.

A well-synchronized circadian system is a manifestation of an individual's health. A gradual weakening of the circadian timing function characterizes aging. Regular exercise has been suggested as a modality to improve many detrimental changes associated with aging. Therefore, we aim to examine the benefits and risks of lifelong endurance exercise on age-dependent changes in the circadian time-keeping function, the performance of the muscular system and health status. The study protocol has a comparative cross-sectional design, including groups of senior (65 to 75 years old, n=16) and young (20-30 years old, n=16) endurance runners and triathletes. Age-matched groups of young and elderly sedentary men are included as controls. The circadian function is evaluated mainly by measurement of urinary 6-sulphatoxymelatonin, a metabolite of the hormone melatonin shown to participate in the modulation of sleep cycles. The 6-sulphatoxymelatonin will be assessed in urine samples collected upon awakening in the morning and in the late evening, as a marker of melatonin production. In addition, sleep/activity rhythms and sleep quality will be measured by wrist actigraphy. Performance of the muscular system will be assessed by examination of muscular strength and quantifying of gene expression in the skeletal muscle tissue samples. Health status and age-induced reduction in immune function are to be analysed via the balance of pro- and anti-inflammatory immune markers in the plasma and skeletal muscle, body composition, bone density and physical fitness.

Chronodisruption of the acute inflammatory response by night lighting in rats.

Daily oscillations are present in many aspects of the immune system, including responsiveness to infections, allowing temporal alignment of defence mechanisms with the external environment. Our study addresses whether compromised circadian timing function by dim artificial light at night (ALAN) impacts the time dependency of the acute inflammatory response in a rat model of lipopolysaccharide (LPS)-induced inflammation. After 2 weeks of exposure to low-intensity ALAN (~2 lx) or a standard light/dark cycle, male rats were challenged with LPS during either the day or the night. Dim ALAN attenuated the anorectic response when rats were stimulated during their early light phase. Next, ALAN suppressed daily variability in inflammatory changes in blood leukocyte numbers and increased the daytime sensitivity of neutrophils to the priming effects of LPS on oxidative burst. An altered renal inflammatory response in ALAN-exposed rats was manifested by stimulated T-cell infiltration into the kidney upon night-time LPS injection and the modified rhythmic response of genes involved in inflammatory pathways. Moreover, ALAN disturbed steady-state oscillations of the renal molecular clock and eliminated the inflammatory responsiveness of Rev-erbα. Altogether, dim ALAN impaired time-of-day-dependent sensitivity of inflammatory processes, pointing out a causal mechanism between light pollution and negative health effects.

A Single Infusion of Polyethylene Glycol-Coated Superparamagnetic Magnetite Nanoparticles Alters Differently the Expressions of Genes Involved in Iron Metabolism in the Liver and Heart of Rats.

This study investigated genotype- and tissue-related differences in the biodistribution of superparamagnetic magnetite (Fe3O4) nanoparticles (IONs) into the heart and liver of normotensive Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats after a single i.v. infusion of polyethylene glycol-coated IONs (~30 nm, 1mg Fe/kg) 100 min post-infusion. The effects of IONs on the expression of selected genes involved in the regulation of iron metabolism, including Nos, Sod and Gpx4, and their possible regulation by nuclear factor (erythroid-derived 2)-like 2 (NRF2, encoded by Nfe2l2) and iron-regulatory protein (encoded by Irp1) were investigated. In addition, superoxide and nitric oxide (NO) production were determined. Results showed reduced ION incorporations into tissues of SHR compared to WKY and in the hearts compared to the livers. IONs reduced plasma corticosterone levels and NO production in the livers of SHR. Elevated superoxide production was found only in ION-treated WKY. Results also showed differences in the regulation of iron metabolism on the gene level in the heart and liver. In the hearts, gene expressions of Nos2, Nos3, Sod1, Sod2, Fpn, Tf, Dmt1 and Fth1 correlated with Irp1 but not with Nfe2l2, suggesting that their expression is regulated by mainly iron content. In the livers, expressions of Nos2, Nos3, Sod2, Gpx4, and Dmt1 correlated with Nfe2l2 but not with Irp1, suggesting a predominant effect of oxidative stress and/or NO.

Disturbances of Hormonal Circadian Rhythms by Light Pollution.

The circadian rhythms evolved to anticipate and cope with cyclic changes in environmental conditions. This adaptive function is currently compromised by increasing levels of artificial light at night (ALAN), which can represent a risk for the development of diseases of civilisation. The causal links are not completely understood, and this featured review focuses on the chronodisruption of the neuroendocrine control of physiology and behaviour by dim ALAN. The published data indicate that low levels of ALAN (2-5 lux) can attenuate the molecular mechanisms generating circadian rhythms in the central oscillator, eliminate the rhythmic changes in dominant hormonal signals, such as melatonin, testosterone and vasopressin, and interfere with the circadian rhythm of the dominant glucocorticoid corticosterone in rodents. These changes are associated with a disturbed daily pattern of metabolic changes and behavioural rhythms in activity and food and water intake. The increasing levels of ALAN require the identification of the pathways mediating possible negative consequences on health to design effective mitigation strategies to eliminate or minimise the effects of light pollution.

Artificial Dim Light at Night during Pregnancy Can Affect Hormonal and Metabolic Rhythms in Rat Offspring.

Artificial light at night (ALAN) is considered an environmental risk factor that can interfere with the circadian control of the endocrine system and metabolism. We studied the impact of ALAN during pregnancy on the hormonal and biochemical parameters in rat pups at postnatal (P) days P3, P10, and P20. Control dams (CTRL) were kept in a standard light-dark regime, and ALAN dams were exposed to dim ALAN (<2 lx) during the whole pregnancy. A plasma melatonin rhythm was found in all CTRL groups, whereas in ALAN pups, melatonin was not rhythmic at P3, and its amplitude was lowered at P10; no differences were found between groups at P20. Plasma corticosterone was rhythmic at P20 in both groups, with decreased mesor in ALAN pups. Plasma thyroid hormones exhibited an inconsistent developmental pattern, and vasopressin levels were suppressed at the beginning of the dark phase at P20 in ALAN compared to CTRL. Glucose and cholesterol showed significant daily rhythms in CTRL but not in ALAN offspring at P3. Exposure to ALAN during pregnancy disturbed the development of daily rhythms in measured hormones and metabolites, suggesting that ALAN during pregnancy can act as an endocrine disruptor that can interfere with the normal development of the progeny.

Circadian Disruption and Consequences on Innate Immunity and Inflammatory Response.

Circadian rhythms control almost all aspects of physiology and behavior, allowing temporal synchrony of these processes between each other, as well as with the external environment. In the immune system, daily rhythms of leukocyte functions can determine the strength of the immune response, thereby regulating the efficiency of defense mechanisms to cope with infections or tissue injury. The natural light/dark cycle is the prominent synchronizing agent perceived by the circadian clock, but this role of light is highly compromised by irregular working schedules and unintentional exposure to artificial light at night (ALAN). The primary concern is disrupted circadian control of important physiological processes, underlying potential links to adverse health effects. Here, we first discuss the immune consequences of genetic circadian disruption induced by mutation or deletion of specific clock genes. Next, we evaluate experimental research into the effects of disruptive light/dark regimes, particularly light-phase shifts, dim ALAN, and constant light on the innate immune mechanisms under steady state and acute inflammation, and in the pathogenesis of common lifestyle diseases. We suggest that a better understanding of the mechanisms by which circadian disruption influences immune status can be of importance in the search for strategies to minimize the negative consequences of chronodisruption on health.

Exposure to dim light at night alters daily rhythms of glucose and lipid metabolism in rats.

Nocturnal light pollution has been rapidly increasing during the last decades and even though dim artificial light at night (ALAN) has been associated with metabolic diseases, its mechanism is still far from clear. Therefore, the aim of our study was to thoroughly analyze the effects of ALAN on energy metabolism, metabolites, metabolic hormones, and gene expression. Male Wistar rats were kept in either the standard light:dark (12:12) cycle or exposed to ALAN (∼2 lx) during the whole 12-h dark phase for 2 weeks. Energy metabolism was measured in metabolic cages. In addition, we measured plasma and hepatic metabolites, clock and metabolic gene expression in the liver and epididymal adipose tissue, and plasma hormone levels. In ALAN rats, we observed an unexpected transitory daytime peak of locomotor activity and a suppression of the peak in locomotor activity at the beginning of the dark period. These changes were mirrored in the respiratory exchange ratio. Plasma metabolites became arrhythmic, and plasma and hepatic cholesterol levels were increased. Lost rhythmicity of metabolites was associated with disrupted behavioral rhythms and expression of metabolic genes. In the liver, the rhythms of metabolic sensors were either phase-advanced (Ppara, Pgc1a, Nampt) or arrhythmic (Sirt1, Lxra) after ALAN. The rhythmic pattern of Ppara and Sirt1 was abolished in the adipose tissue. In the liver, the amplitude of the daily rhythm in glycogen content was attenuated, the Glut2 rhythm was phase-advanced and Foxo1 lost its daily rhythmicity. Moreover, hepatic Foxo1 and Gck were up-regulated after ALAN. Interestingly, several parameters of lipid metabolism gained rhythmicity (adiponectin, Hmgcs2, Lpl, Srebf1c) in the liver, whereas Noct became arrhythmic in the adipose tissue. Peripheral clock genes maintained their robust oscillations with small shifts in their acrophases. Our data show that even a low level of ALAN can induce changes in the daily pattern of behavior and energy metabolism, and disturb daily rhythms of genes encoding key metabolic sensors and components of metabolic pathways in the liver and adipose tissue. Disturbed metabolic rhythms by ALAN could represent a serious risk factor for the development and progression of metabolic diseases.

Disrupted Circadian Control of Hormonal Rhythms and Anticipatory Thirst by Dim Light at Night.

AIMS: Our study addresses underlying mechanisms of disruption of the circadian timing system by low-intensity artificial light at night (ALAN), which is a growing global problem, associated with serious health consequences. METHODS: Rats were exposed to low-intensity (∼2 lx) ALAN for 2 weeks. Using in situ hybridization, we assessed 24-h profiles of clock and clock-controlled genes in the suprachiasmatic nuclei (SCN) and other hypothalamic regions, which receive input from the master clock. Moreover, we measured the daily rhythms of hormones within the main neuroendocrine axes as well as the detailed daily pattern of feeding and drinking behavior in metabolic cages. RESULTS: ALAN strongly suppressed the molecular clockwork in the SCN, as indicated by the suppressed rhythmicity in the clock (Per1, Per2, and Nr1d1) and clock output (arginine vasopressin) genes. ALAN disturbed rhythmic Per1 expression in the paraventricular and dorsomedial hypothalamic nuclei, which convey the circadian signals from the master clock to endocrine and behavioral rhythms. Disruption of hormonal output pathways was manifested by the suppressed and phase-advanced corticosterone rhythm and lost daily variations in plasma melatonin, testosterone, and vasopressin. Importantly, ALAN altered the daily profile in food and water intake and eliminated the clock-controlled surge of drinking 2 h prior to the onset of the rest period, indicating disturbed circadian control of anticipatory thirst and fluid balance during sleep. CONCLUSION: Our findings highlight compromised time-keeping function of the central clock and multiple circadian outputs, through which ALAN disturbs the temporal organization of physiology and behavior.

Evidence That Artificial Light at Night Induces Structure-Specific Changes in Brain Plasticity in a Diurnal Bird.

We recently reported that artificial light at night (ALAN), at ecologically relevant intensities (1.5, 5 lux), increases cell proliferation in the ventricular zone and recruitment of new neurons in several forebrain regions of female zebra finches (Taeniopygia guttata), along with a decrease of total neuronal densities in some of these regions (indicating possible neuronal death). In the present study, we exposed male zebra finches to the same ALAN intensities, treated them with 5'-bromo-2'-deoxyuridine, quantified cell proliferation and neuronal recruitment in several forebrain regions, and compared them to controls that were kept under dark nights. ALAN increased cell proliferation in the ventricular zone, similar to our previous findings in females. We also found, for the first time, that ALAN increased new neuronal recruitment in HVC and Area X, which are part of the song system in the brain and are male-specific. In other brain regions, such as the medial striatum, nidopallium caudale, and hippocampus, we recorded an increased neuronal recruitment only in the medial striatum (unlike our previous findings in females), and relative to the controls this increase was less prominent than in females. Moreover, the effect of ALAN duration on total neuronal densities in the studied regions varied between the sexes, supporting the suggestion that males are more resilient to ALAN than females. Suppression of nocturnal melatonin levels after ALAN exhibited a light intensity-dependent decrease in males in contrast to females, another indication that males might be less affected by ALAN. Taken together, our study emphasizes the importance of studying both sexes when considering ALAN effects on brain plasticity.

Dim Light at Night Disturbs Molecular Pathways of Lipid Metabolism.

Dim light at night (dLAN) is associated with metabolic risk but the specific effects on lipid metabolism have only been evaluated to a limited extent. Therefore, to explore whether dLAN can compromise lipid metabolic homeostasis in healthy individuals, we exposed Wistar rats to dLAN (~2 lx) for 2 and 5 weeks and analyzed the main lipogenic pathways in the liver and epididymal fat pad, including the control mechanisms at the hormonal and molecular level. We found that dLAN promoted hepatic triacylglycerol accumulation, upregulated hepatic genes involved in de novo synthesis of fatty acids, and elevated glucose and fatty acid uptake. These observations were paralleled with suppressed fatty acid synthesis in the adipose tissue and altered plasma adipokine levels, indicating disturbed adipocyte metabolic function with a potential negative impact on liver metabolism. Moreover, dLAN-exposed rats displayed an elevated expression of two peroxisome proliferator-activated receptor family members (Pparα and Pparγ) in the liver and adipose tissue, suggesting the deregulation of important metabolic transcription factors. Together, our results demonstrate that an impaired balance of lipid biosynthetic pathways caused by dLAN can increase lipid storage in the liver, thereby accounting for a potential linking mechanism between dLAN and metabolic diseases.

Differential Effects of Constant Light and Dim Light at Night on the Circadian Control of Metabolism and Behavior.

The disruption of circadian rhythms by environmental conditions can induce alterations in body homeostasis, from behavior to metabolism. The light:dark cycle is the most reliable environmental agent, which entrains circadian rhythms, although its credibility has decreased because of the extensive use of artificial light at night. Light pollution can compromise performance and health, but underlying mechanisms are not fully understood. The present review assesses the consequences induced by constant light (LL) in comparison with dim light at night (dLAN) on the circadian control of metabolism and behavior in rodents, since such an approach can identify the key mechanisms of chronodisruption. Data suggest that the effects of LL are more pronounced compared to dLAN and are directly related to the light level and duration of exposure. Dim LAN reduces nocturnal melatonin levels, similarly to LL, but the consequences on the rhythms of corticosterone and behavioral traits are not uniform and an improved quantification of the disrupted rhythms is needed. Metabolism is under strong circadian control and its disruption can lead to various pathologies. Moreover, metabolism is not only an output, but some metabolites and peripheral signal molecules can feedback on the circadian clockwork and either stabilize or amplify its desynchronization.

Artificial Light at Night Increases Recruitment of New Neurons and Differentially Affects Various Brain Regions in Female Zebra Finches.

Despite growing evidence that demonstrate adverse effects of artificial light at night (ALAN) on many species, relatively little is known regarding its effects on brain plasticity in birds. We recently showed that although ALAN increases cell proliferation in brains of birds, neuronal densities in two brain regions decreased, indicating neuronal death, which might be due to mortality of newly produced neurons or of existing ones. Therefore, in the present study we studied the effect of long-term ALAN on the recruitment of newborn neurons into their target regions in the brain. Accordingly, we exposed zebra finches (Taeniopygia guttata) to 5 lux ALAN, and analysed new neuronal recruitment and total neuronal densities in several brain regions. We found that ALAN increased neuronal recruitment, possibly as a compensatory response to ALAN-induced neuronal death, and/or due to increased nocturnal locomotor activity caused by sleep disruption. Moreover, ALAN also had a differential temporal effect on neuronal densities, because hippocampus was more sensitive to ALAN and its neuronal densities were more affected than in other brain regions. Nocturnal melatonin levels under ALAN were significantly lower compared to controls, indicating that very low ALAN intensities suppress melatonin not only in nocturnal, but also in diurnal species.

Dim Light at Night Impairs Daily Variation of Circulating Immune Cells and Renal Immune Homeostasis.

Dim light at night (dLAN) has become a pervasive part of the modern world, and growing evidence shows its association with increased health risks. Though this link is attributed to a disturbed circadian clock, the underlying mechanisms that can explain how circadian disruption from dLAN causes negative health effects remain unclear. Here, we exposed rats to a light-dark cycle (12:12 h) with low-intensity light at night (~2 lx) for 2 and 5 weeks and explored the steady-state pattern of circulating immune cells and renal immune-related markers, which are well controlled by the circadian clock. After 5 weeks, dLAN impaired the daily variation in several types of white blood cells, especially monocytes and T cells. Two-week dLAN caused a reduction in blood monocytes and altered gene expression of macrophage marker Cd68 and monocyte-attracting chemokine Ccl2 in the kidney. Interestingly, dLAN decreased renal 3-nitrotyrosine levels and resulted in up-regulation of the main endogenous antioxidant pathways, indicating a disturbance in the renal redox balance and an activation of compensatory mechanisms. These effects paralleled the altered renal expression of the molecular clock components and increased plasma corticosterone levels. Together, our results show that chronic exposure to dLAN weakened the circadian control of daily variation of circulating immune cells and disturbed renal immune and redox homeostasis. Consequences of this dLAN-disturbed immune balance on the ability of the immune system to cope with other challenges should by clarified in further studies.

Artificial light at night affects brain plasticity and melatonin in birds.

Artificial light at night (ALAN), which disrupts the daily cycle of light, has vast biological impacts on all organisms, and is also associated with several health problems. The few existing studies on neuronal plasticity and cognitive functions in mammals indicate that a disruption of the circadian cycle impairs learning and memory and suppresses neurogenesis. However, nothing is known about the effect of ALAN on neuronal plasticity in birds. To this end, zebra finches (Taeniopygia guttata) were exposed to ecologically relevant ALAN intensities (0.5, 1.5 and 5 lx), treated with BrdU to quantify cell proliferation in their ventricular zone (VZ), and compared to controls that were kept under dark nights. We found, in our diurnal birds, that ALAN significantly increased cell proliferation in the VZ. However, neuronal densities in two brain regions decreased under ALAN, suggesting neuronal death. In addition, ALAN suppressed nocturnal melatonin production in a dose-dependent manner, and might also increase body mass. Taken together, our findings add to the notion of the deleterious effect of ALAN.

Dim light at night attenuates circadian rhythms in the cardiovascular system and suppresses melatonin in rats.

AIMS: Cardiovascular parameters exhibit significant 24-h variability, which is coordinated by the suprachiasmatic nucleus (SCN), and light/dark cycles control SCN activity. We aimed to study the effects of light at night (ALAN; 1-2 lx) on cardiovascular system control in normotensive rats. MAIN METHODS: Heart rate (HR) and blood pressure (BP) were measured by telemetry during five weeks of ALAN exposure. From beat-to-beat telemetry data, we evaluated spontaneous baroreflex sensitivity (sBRS). After 2 (A2) and 5 (A5) weeks of ALAN, plasma melatonin concentrations and the response of BP and HR to norepinephrine administration were measured. The expression of endothelial nitric oxide synthase (eNOS) and endothelin-1 was determined in the aorta. Spontaneous exploratory behaviour was evaluated in an open-field test. KEY FINDINGS: ALAN significantly suppressed the 24-h variability in the HR, BP, and sBRS after A2, although the parameters were partially restored after A5. The daily variability in the BP response to norepinephrine was reduced after A2 and restored after A5. ALAN increased the BP response to norepinephrine compared to the control after A5. Increased eNOS expression was found in arteries after A2 but not A5. Endothelin-1 expression was not affected by ALAN. Plasma melatonin levels were suppressed after A2 and A5. Spontaneous exploratory behaviour was reduced. SIGNIFICANCE: ALAN decreased plasma melatonin and the 24-h variability in the haemodynamic parameters and increased the BP response to norepinephrine. A low intensity ALAN can suppress circadian control of the cardiovascular system with negative consequences on the anticipation of a load.

Consequences of low-intensity light at night on cardiovascular and metabolic parameters in spontaneously hypertensive rats 1.

Circadian rhythms are an inherent property of physiological processes and can be disturbed by irregular environmental cycles, including artificial light at night (ALAN). Circadian disruption may contribute to many pathologies, such as hypertension, obesity, and type 2 diabetes, but the underlying mechanisms are not understood. Our study investigated the consequences of ALAN on cardiovascular and metabolic parameters in spontaneously hypertensive rats, which represent an animal model of essential hypertension and insulin resistance. Adult males were exposed to a 12 h light - 12 h dark cycle and the ALAN group experienced dim light at night (1-2 lx), either for 2 or 5 weeks. Rats on ALAN showed a loss of light-dark variability for systolic blood pressure, but not for heart rate. Moreover, a gradual increase of systolic blood pressure was recorded over 5 weeks of ALAN. Exposure to ALAN increased plasma insulin and hepatic triglyceride levels. An increased expression of metabolic transcription factors, Pparα and Pparγ, in the epididymal fat and a decreased expression of Glut4 in the heart was found in the ALAN group. Our results demonstrate that low-intensity ALAN can disturb blood pressure control and augment insulin resistance in spontaneously hypertensive rats, and may represent a serious risk factor for cardiometabolic diseases.

Age-specific patterns of maternal investment in common gull egg yolk.

While the general patterns of age-specific changes in reproductive success are quite well established in long-lived animals, we still do not know if allocation patterns of maternally transmitted compounds are related to maternal age. We measured the levels of yolk testosterone, carotenoids and vitamins A and E in a population of known-aged common gulls (Larus canus) and found an age-specific pattern in yolk lutein and vitamin A concentrations. Middle-aged mothers allocated more of these substances to yolk compared to young and old mothers. These results can be explained through differences in age-specific foraging, absorption or deposition patterns of carotenoids and vitamins into yolk. If these molecules play a role in antioxidant defence and immune modulation, our results suggest a possible physiological pathway underlying the age-specific changes in reproductive success of long-lived birds in the wild.

Effect of oral contraceptives intake on postural stability in young healthy women throughout the menstrual cycle.

The purpose of the study was to investigate the effect of oral contraceptives on static postural stability in young healthy women during their menstrual cycle. Twenty-three women with the regular menstrual cycle, using or not using oral contraceptives, participated in this study. Salivary progesterone and estradiol levels were measured during one menstrual cycle. Measurements of balance were performed during a quiet stance on a firm and foam surface by the force platform, with eyes either opened or closed, on day 2, 7, 14, 21 and 28 of the cycle. Results of stability on a firm surface with eyes opened showed a significant effect in the amplitude of body sway in the anterior-posterior direction since women using oral contraceptives had a lower amplitude compared to control women on day 28. During stance on a firm surface with eyes closed we showed only impact of the menstrual cycle on postural stability of women. In condition of stance on a foam surface with the eyes opened or closed no significant effects were found. Our results showed that oral contraceptives intake can improve the static postural stability before the onset of menstruation and decrease a risk of injury of young healthy women.

In ovo yolk carotenoid and testosterone levels interactively influence female transfer of yolk antioxidants to her eggs.

Mothers can influence prenatal conditions by varying the amount of nutrients, hormones or antioxidants they provide to their developing young. Some of these substances even affect the transfer of these compounds in the next generation, but it is less clear how different maternally transmitted compounds interact with each other to shape reproductive resource allocation in their offspring. Here, we found that female Japanese quails (Coturnix japonica) that were exposed to high carotenoid levels during embryonic development transferred lower concentrations of yolk antioxidants to their own eggs later in life. This effect disappeared when both testosterone and carotenoid concentrations were manipulated simultaneously, showing long-term and interactive effects of these maternally derived egg components on a female's own egg composition. Given that exposure to high levels of testosterone during embryo development stimulates the production of reactive oxygen species (ROS) and impairs antioxidant defenses, we propose that carotenoids act as in ovo antioxidants in an oxidatively stressful environment (i.e. when levels of testosterone are high) but might have prooxidant properties in an environment where they are not used to counteract an increased production of ROS. In line with this hypothesis, we previously showed that prenatal exposure to increased concentrations of yolk carotenoids leads to a rise of oxidative damage at adulthood, but only when yolk testosterone concentrations were not experimentally increased as well. As a consequence, antioxidants in the body may be used to limit oxidative damage in females exposed to high levels of carotenoids during development (but not in females exposed to increased levels of both carotenoids and testosterone), resulting in lower amounts of antioxidants being available for deposition into eggs. Since prenatal antioxidant exposure is known to influence fitness-related traits, the effect detected in this study might have transgenerational consequences.