The Role of Alpha-Tocotrienol during Development of Primary Hippocampal Neurons

Objectives

Alpha-tocotrienol (α-TCT), a form of vitamin E, is a lipophilic antioxidant with neuroprotective properties. We recently reported that α-TCT treatment prevents oxidative stress-induced proteolytic cleavage of B-cell lymphoma-extra large (Bcl-xL), a pro-survival mitochondrial protein necessary during neuronal growth. However, it is still unclear if α-TCT exhibits beneficial effects during the physiological development of neurons. In this study, we hypothesized that chronic α-TCT treatment advances the development of primary hippocampal neurons by improving mitochondrial function.

Methods

Primary rat hippocampal neurons were grown in neurobasal media with or without α-TCT for three weeks, and media was replaced with conditioned media containing fresh α-TCT every week. Intracellular α-TCT levels were quantified using HPLC-MS, and intracellular ATP and mitochondrial superoxide levels were determined using luciferase and mitoSOX, respectively. Neurite morphology was examined by Sholl analysis. mRNA and protein levels of Bcl-xL were quantified using qPCR and immunoblotting, respectively.

Results

Primary hippocampal neurons grown in media containing α-TCT had increased intracellular α-TCT levels and decreased mitochondrial superoxide. Treatment with α-TCT increased mRNA and protein levels of Bcl-xL, neuronal ATP, and the number of neurite branches in primary hippocampal neurons.

Conclusions

We found that primary rat hippocampal neurons treated with α-TCT developed advanced neurite complexity. We suggest that α-TCT treatment improves mitochondrial function via upregulation of Bcl-xL, supporting normal neuron development.

Funding Sources

RGC Program (University of Alabama); Crenshaw Research Fund (University of Alabama).

Diet Quality Assessed by the Dietary Inflammatory Index and the Healthy Eating Index: An Analysis of the National Health and Nutrition Examination Survey (2015–2018)

Objectives

The Healthy Eating Index (HEI) is a measure of diet quality that assesses adherence to the Dietary Guidelines for Americans. In contrast, the Dietary Inflammatory Index (DII) evaluates the inflammatory potential of the diet by assessing foods and nutrients based on their effect on inflammatory biomarkers. In study populations outside of the U.S., the HEI and DII scores were inversely associated, yet not all studies adjusted DII for energy intake whereas HEI is scored on a density basis of 1,000 calories. Thus, the purpose of this study was to evaluate the relationship between HEI-2015 and DII using tertiles of energy intake among U.S. adults.

Methods

Analyses were conducted with data from 3,322 adults (ages 20–50 years, 54.5% female) participating in the National Health and Nutrition Examination Survey 2015–2018. Both the DII and HEI-2015 were computed using data from two 24-hour recalls. Next, DII scores were converted to tertiles (low, moderate, and high) and individuals in these groupings were then placed into separate tertiles of energy intake (low, moderate, and high) resulting in nine DII-Energy groups. Differences in HEI-2015 scores across the nine energy-adjusted groups were assessed using linear regression.

Results

Low DII scores indicate a more anti-inflammatory dietary pattern and are associated with higher HEI scores (more compliant to Dietary Guidelines for Americans). Males in the Low Inflammation-Low Energy group had significantly higher HEI scores compared to High Inflammation-High Energy group (M = 63.58 and 38.99, respectively, β = 24.51, p < 0.0001). In females, those in the Low Inflammation-Moderate Energy group had significantly higher HEI scores compared to High Inflammation-High Energy group (M = 65.08 and 38.83, respectively, β = 26.95, p < 0.0001). Overall, the variance explained by the model for males and females was 29.8% and 34.1%, respectively.

Conclusions

Results suggest that adherence to the Dietary Guidelines for Americans translated into a more anti-inflammatory diet pattern in U.S. adults. Acknowledging the relationship between inflammation, diet quality, and energy, the DII may need to be energy-adjusted. This is especially true when comparing DII to other indices that account for energy intake.

Funding Sources

The authors have no funding sources to disclose for this research.

Effects of Different 16-Week Exercise Interventions on Bone Mineral Density of Sedentary Older Women

Multicomponent exercise that includes both resistance and aerobic training is recommended to prevent loss of bone mineral density (BMD) in postmenopausal women. However, optimal training frequency has not been determined. Sixty-three non-osteoporotic sedentary women ages 60y and older were randomized to one of three exercise groups for sixteen weeks: 1) one resistance and one aerobic session per week, 2) two resistance and two aerobic sessions per week, or 3) three resistance and three aerobic sessions per week. Resistance exercise included supervised sessions on weight machines, and aerobic exercise was treadmill walking. BMD of the hip and lumbar spine (L1-L4) was assessed by dual energy X-ray absorptiometry (Prodigy, GE Medical Systems Lunar, Madison, WI, software version 6.10.029), and z scores were calculated from a reference population adjusted for age and sex. Among the total cohort with BMD measurements at week 16 (n=58; 83% white), z scores improved for the trochanter, Ward’s triangle, total hip, L1 and L4. Within-group comparisons showed improvement at the trochanter, total hip, and L1 for group 2 only, while only group 1 demonstrated an increase at L4 (p<0.05 for all). However, no time-by-group interactions were observed. Sixteen weeks of combined resistance and aerobic training is effective for improving BMD of older adult women. Results suggest training frequency of two sessions per week may be optimal. Postmenopausal women should be encouraged to do aerobic exercise such as walking plus resistance training at least once weekly to prevent osteoporosis.

Changes in the Visceral Adiposity Index (VAI) Among Obese Older Adults After a 12-Month Exercise and Diet Intervention

Objectives

The Visceral Adiposity Index (VAI) was developed to estimate adipose tissue dysfunction as well as visceral fat distribution. In an ancillary analysis of the CROSSROADS Study (clinicaltrials.gov #NCT00955903), this study investigated the effects of exercise with and without intentional energy restriction on VAI changes among older adults with obesity.

Methods

Participants (n = 163, 37.4% male, 70.3 ± 4.7 years) were randomized to the following groups: exercise only, exercise + nutrient-dense weight maintenance diet, and exercise + nutrient-dense energy restriction of 500 kcal/d. Visceral adiposity determined by magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA), anthropometrics, and cardiometabolic biomarkers were assessed at baseline and 12 months. Waist circumference, body mass index, triglycerides, and high-density lipoprotein (HDL) cholesterol were used to compute VAI at both time points. Data were analyzed utilizing Spearman's correlations and general linear models to determine differences among groups following adjustment for covariates.

Results

Among all participants, significant correlations were observed between VAI and glucose, insulin, tumor necrosis factor-alpha (TNF-α), and the adiponectin: leptin ratio at baseline (r = 0.343, P &lt; 0.001; r = 0.363, P &lt; 0.001; r = 0.200, P = 0.011; r = −0.246, P = 0.002, respectively). DXA and MRI measures of visceral adiposity were not significantly correlated with VAI. Upon completion of the 12-month study period, there were significant differences in VAI among groups [F (2,137) = 5.957, P = 0.003)]. Post hoc analysis revealed that VAI was significantly lower in the exercise + nutrient-dense energy restriction group compared to the exercise only group (P = 0.002).

Conclusions

Results suggest that VAI may be an adequate measure of adipose tissue dysfunction, yet its ability to estimate levels of visceral adiposity warrants further investigation to determine clinical utility. Nonetheless, results suggest that an exercise + nutrient-dense energy restriction intervention may reduce VAI among older adults with obesity.

Funding Sources

NIH.

Association of Drug Burden Index With Measures of Cognitive Function Among Older Adults

Objectives

Many conditions associated with aging result in polypharmacy, and certain medications may impact cognition. One way to assess exposure to such medications is through the use of the drug burden index (DBI)- a validated measure of exposure to anticholinergic and sedative medications, with a higher DBI score indicating a higher drug burden. The objective of this cross-sectional analysis was to investigate the association between DBI and cognitive function assessed by two widely utilized cognitive tests among older adults.

Methods

The Health, Aging, and Body Composition Study was a prospective study of community-dwelling adults ages 70–79 years at enrollment. Using baseline data, DBI was calculated by dividing the daily dose of the medication taken by the sum of the daily dose taken and the minimum efficacious dose as approved by the Food and Drug Association. After adjusting for biological sex, race, education,

and APOE genotype, the association between DBI and the Digit Symbol Substitution Test (DSST) and Modified Mini-Mental Status Exam (3MS) score was assessed by partial Spearman's rank correlation. Kruskal-Wallis tests were employed to assess significance among DBI scores by tertile.

Results

Among those with completed measures (n = 790, 52.4% male, 63.3% white), mean scores were as follows: DBI 0.84 ± 0.48, 3MS 90.12 ± 7.9, and DSST 34.7 ± 14.6. Results suggest that DBI was not significantly associated with either 3MS or DSST. However, DBI scores by tertile were significantly associated with DSST scores. Compared to tertile 2, participants in the lowest tertile had significantly lower DBI scores along with significantly higher DSST scores. Mean differences between tertile 1 and 2 were as follows: DBI = 0.1666 and DSST = 3.39.

Conclusions

Analyses among the full cohort suggest that DBI was not associated with slower processing speed as assessed by the DSST or with global cognition as assessed by 3MS. Yet with expanded analysis by tertile, results suggest that DBI scores were significantly associated with DSST scores. Future investigations on cognitive function among older adults may benefit from including the DBI analysis by tertile to explain some variance in cognitive test scores.

Funding Sources

This is an ancillary analysis, there is no funding applicable.

Vitamin E Improves Neurite Complexity by Enhancing Mitochondrial Function

Objectives

Neurite outgrowth is a foundational process in brain development and recovery from brain injury. Assembly of the cytoskeleton and formation of new synapses during neurite outgrowth requires an abundance of energy. We have reported that the mitochondrial protein Bcl-xL is necessary for neurite outgrowth and arborization. However, Bcl-xL undergoes post-translational cleavage during oxidative stress resulting in a product that impairs mitochondrial function. Our recent publication demonstrated that treatment with alpha-tocotrienol, an antioxidant member of the vitamin E family, prevents cleavage of Bcl-xL and protects neurons from oxidative stress. In this study, we hypothesize that treatment with alpha-tocotrienol improves mitochondrial function to support the energy demanding processes of growth and development in the neurons.

Methods

Primary hippocampal neurons were grown in neurobasal media with or without alpha-tocotrienol for 3 weeks. Then, the number of neurite branches was quantified applying Sholl analysis. We also assayed the ATP/ADP ratio at neurites using the PercevalHR fluorescence biosensor. mRNA and protein levels of total Bcl-xL and cleaved Bcl-xL were measured using real time PCR and immunoblotting.

Results

Neurons grown with alpha-tocotrienol achieved more advanced neurite complexity than the control group. Treatment with alpha-tocotrienol enhanced both total ATP and local neurite ATP levels in primary hippocampal neurons. Furthermore, we found that alpha-tocotrienol Increased mRNA and protein levels of Bcl-xL without enhancing post-translational cleavage of Bcl-xL, consistent with our previous study.

Conclusions

Our data show that alpha-tocotrienol improves mitochondria-mediated ATP production by enhancing Bcl-xL to support metabolically demanding processes in neurons. We suggest a novel function of alpha-tocotrienol in normal physiological development of the brain. This study also suggests a potential therapeutic role of alpha-tocotrienol in brain diseases associated with neurite injury.

Funding Sources

RGC Program (University of Alabama) Crenshaw Research Fund (University of Alabama).

Change in Body Mass Index is Associated with Change in Cognition in Older Adults

Background: Alzheimer’s disease and related dementias affect one in ten Americans age 65y and older. Considering the rapid growth of the aging population, identifying modifiable risk factors for cognitive decline is a public health priority. Although weight change later in life is common, its impact on cognition is unclear. The objective of this study was to examine the relationship between change in body mass index (BMI) and cognition among older adults. Methods: The Health, Aging, and Body Composition Study was a prospective study of community-dwelling adults ages 70-79y at baseline (n=3,075; 49% males, 42% African-American). Using baseline and year 10 visit data, we evaluated change in BMI and change in cognition measured by the Modified Mini-Mental Status Exam (3MS) using a linear mixed model. Change in 3MS scores were regressed on changes in time-varying BMI after controlling for blood pressure, glucose, cholesterol, race, education, biological sex, and APOE genotype. Results: At baseline, average BMI was 27.4 (n=3075) and average 3MS was 90.1 (n=3061). At year 10, average BMI was 27.1 (n=1600) and average 3MS was 88.6 (n=1598). Higher BMI was associated with less cognitive decline (ceteris paribus). This finding suggests that weight gain is associated with cognitive maintenance. The effect of an increase in BMI was largest for those underweight at baseline. Conclusion: Among underweight older adults, an increase in BMI may be desirable for maintaining cognition. Although more research is needed, these findings suggest the need for interventions to prevent unintentional weight loss among older adults.

Roles of Vitamin E in Energy Metabolism During Neurite Outgrowth

Objectives

Neurite outgrowth is a pivotal process of brain development and recovery after brain injury. This metabolically demanding process requires assembly of the cytoskeleton and formation and maintenance of synapses. We have recently found that treatment with alpha-tocotrienol, an antioxidant and a member of the vitamin E family, prevents loss of mitochondrial inner membrane potential during oxidative stress. In this study, we hypothesize that the mitochondrion is the central target of alpha-tocotrienol-mediated neuroprotection, and treatment with alpha-tocotrienol may improve neuronal energy metabolism and promote neurite outgrowth.

Methods

Primary hippocampal neurons were grown in neurobasal media with or without alpha-tocotrienol for 3 weeks. Then, the morphological development of neurites, including polarity and arborization, was analyzed. We also assayed the ATP: ADP ratio in neurites using PercevalHR fluorescence biosensor after treatment with alpha-tocotrienol.

Results

Neurons grown with alpha-tocotrienol achieved neuronal polarity prior to the control group, and alpha-tocotrienol treated neurons showed longer and more branched neurites compared to the control group. Treatment with alpha-tocotrienol enhanced ATP levels in primary hippocampal neurons.

Conclusions

Our data show that alpha-tocotrienol improves mitochondria-mediated ATP production and supports the metabolically demanding process of neurite growth. This study also suggests that alpha-tocotrienol may be beneficial for recovery after brain injuries associated with neurite loss.

Funding Sources

RG14811 (University of Alabama).

Vitamin A Supplementation During Suckling and Post-Weaning Periods Improves Systemic and Adipose Tissue Redox Status in Offspring of Rats Consuming a High-Fat Diet

Objectives

Dietary fat can contribute to oxidative stress and adipose tissue (AT) accrual which exacerbates redox imbalance. Vitamin A (VA) has been shown to regulate AT development and associated metabolic conditions in adult models; however, such effects of VA in early life stages, especially on redox status, has barely been studied. The aim of this study was to assess the effects of VA supplementation during suckling and post-weaning periods on systemic and AT redox status in rats reared by mothers consuming a high-fat diet (HFD).

Methods

Sprague-Dawley rats arrived on their second day of gestation and were randomized to either a normal-fat diet (NFD = 25% fat) or a HFD (50% fat) both with adequate VA at 2.6 mg/kg. Upon delivery of pups, half of rat mothers from the NFD cohort or HFD cohort were switched to a NFD or a HFD both with supplemented VA at 129 mg/kg (NFD + VA and HFD + VA group), respectively. The other half of mothers remained on their diets with adequate VA (NFD and HFD group). At postnatal day 14 (P14), P25, and P35, pups (n = 4 or 3/group/time point) were euthanized. Concentrations of VA, lipid peroxides, and antioxidant capacity (AC) of serum, visceral white AT (WAT) and brown AT (BAT) were measured.

Results

At all three time points, the lipid peroxides concentration in WAT was significantly lower in VA-supplemented groups as compared to their respective control (P &lt; 0.0001 for NFD + VA vs. NFD; P &lt; 0.05 for HFD + VA vs. HFD); lipid peroxides were significantly (P &lt; 0.01) higher in the HFD + VA group than in the NFD + VA group. A significantly (P &lt; 0.05) positive correlation between the amount of VA and the lipophilic AC of the WAT was noted. For BAT, the NFD + VA group showed a significantly (P &lt; 0.001) lower lipid peroxides concentration as compared to the NFD group. However, such effect was not observed in the HFD cohort. Serum lipid peroxides in the HFD + VA group were significantly (P &lt; 0.05) lower than in the HFD group. A significant (P &lt; 0.0001) negative correlation was found between the serum concentration of VA and lipid peroxides.

Conclusions

VA supplementation during suckling and post-weaning period improved both the systemic and WAT redox status of rats reared by mothers consuming a HFD, as well as the status within both WAT and BAT of pups nursed by mothers consuming a NFD. The differing results in WAT and BAT may suggest their different roles in redox biology.

Funding Sources

NIH

Differential Effects of Lycopene Supplementation on Adipose Tissue Development and Redox Status in Weanling Offspring of Rats Consuming a High Fat Diet

Objectives

Dietary patterns high in fat contribute to the onset of cardiometabolic disease through accrual of adipose tissue (AT). Nevertheless, carotenoids, such as lycopene, may disrupt these metabolic perturbations. The purpose of this study was to evaluate AT development, systemic and AT redox status, and cardiometabolic biomarkers during weaning and post-weaning periods of offspring from mothers fed high fat diets with and without lycopene supplementation.

Methods

Sprague-Dawley rats arrived on the 2nd day of gestation and were randomized to 25% normal fat diet (NFD) or 50% high fat diet (HFD). Upon delivery, half of HFD mothers were transitioned to HFD supplemented with 1% lycopene (HFDL group). Remaining mothers continued NFD or HFD without supplementation. Four pups/litter were euthanized at postnatal day 25 (P25). Beginning at P25, weanling pups were fed diets of their respective mothers until euthanization at P35 (three pups/litter). Visceral white AT (WAT) and brown AT (BAT) mass was determined, as well as lipid peroxides and antioxidant capacity (AC) of these tissues and serum. Cardiometabolic biomarkers were assessed at P25.

Results

At each time point, HFD groups had significantly greater (P &lt; 0.05) WAT accrual compared to NFD group, sufficiently representing diet-induced obesity. Compared to the HFD group, the HFDL group exhibited significantly greater BAT at P25 (P = 0.025) with a significant reduction in WAT mass (P = 0.004). Such patterns continued into P35, albeit non-significant. At both time points, serum lipid peroxides were significantly lower in the HFDL group compared to the HFD (P = 0.005, P = 0.003, respectively). In contrast, AT results were starkly different such that the HFDL group exhibited significantly greater (P &lt; 0.05) lipid peroxides in WAT and BAT at P25 and P35 compared to HFD group. No significant differences in systemic or AT AC were observed between groups. Furthermore, serum adiponectin and leptin did not differ significantly between groups despite the aforementioned modifications in AT development.

Conclusions

Results from this exploratory analysis suggest that lycopene may induce favorable alterations in AT development, yet it differentially influences redox status in serum and AT. Additional research is warranted to elucidate molecular mechanisms by which lycopene influences AT biology and redox status.

Funding Sources

NIH.

Changes in Cardiometabolic Risk Among Obese Older Adults After a 12-Month Exercise and Diet Intervention

Objectives

Obesity imposes risk to cardiometabolic health; however, intentional weight loss in obese older adults remains controversial. Using data from the CROSSROADS Study (clinicaltrials.gov #NCT00955903), this ancillary study investigated effects of exercise with and without intentional weight loss on changes in cardiometabolic risk assessed by four risk-scoring tools.

Methods

Participants (n = 134, 39% male, 23% African American, 70.2 ± 4.7 y) were randomized to exercise (n = 48), exercise + nutrient-dense weight maintenance diet (n = 44), or exercise + nutrient-dense caloric restriction of 500 kcals/day (n = 42). The following risk scores were calculated using baseline and 12-month data: Framingham risk assessment, Cardiometabolic Disease Staging (CMDS), metabolic syndrome classification by the International Diabetes Federation (IDF), and metabolic syndrome classification by the National Cholesterol Education Program's Adult Treatment Panel (ATP III). Generalized Estimating Equations were employed to determine differences between groups with ethnicity, sex, and age as covariates.

Results

Group-time interaction was not significant in application of IDF or ATPIII. Group-time interaction was significant for Framingham and CMDS (P = 0.005 and 0.041, respectively). Upon post-hoc analysis, significant within-group improvements in Framingham scores were observed for exercise + weight maintenance (P &lt; 0.001, r = −1.682) and exercise + weight loss (P = 0.020, r = −0.881). In analysis of between-group differences in Framingham scores, a significant decrease was observed in the exercise + weight maintenance group (P = 0.001, r = −1.723) compared to the exercise group. For CMDS, the exercise + weight loss group had significant within-group improvements (P = 0.023, r = - 0.102). For between-group differences in CMDS, the exercise + weight loss group showed significant risk score reduction (P = 0.012, r = −0.142) compared to the exercise group.

Conclusions

Risk assessment by Framingham and CMDS showed greater sensitivity to change in cardiometabolic risk factors. Results suggest obese older adults can lower cardiometabolic risk by engaging in exercise + weight maintenance or exercise + weight loss by moderate caloric restriction.

Funding Sources

R01AG033094 NIA, K07AG043588 NIA, P30DK056336 NIDDK.

Vitamin A Status in Neonatal and Weanling Rats Reared by Mothers Consuming Normal and High Fat Diets with or Without Vitamin A Supplementation

Objectives

Although the circulating level of vitamin A (VA) is reported to be significantly lower in obese adults, it is unknown if maternal adiposity would influence the VA status of the offspring. The aim of this study was to investigate the status and distribution of VA in the offspring of rats consuming a normal fat diet (NFD) or a high fat diet (HFD), with or without VA supplementation.

Methods

Sprague-Dawley rats arrived on their second day of gestation and were randomized to either a NFD (25% fat) or a HFD (50% fat) both with an adequate level of VA at 2.6 mg/kg. Upon the delivery of pups, half of rat mothers from the NFD or HFD cohort were switched to a NFD or a HFD both with supplemented VA at 129 mg/kg (NFD + VA and HFD + VA group), respectively. The other half remained on their diets with adequate VA (NFD and HFD group). At postnatal day 14 (P14) and P25, 4 pups/group were euthanized. At P25, the remaining weanling pups (n = 3/group) were fed diets of their respective mothers until being euthanized at P35. Concentrations of total retinol in serum, liver, visceral white AT (WAT), and brown AT (BAT) were measured by UPLC.

Results

Through the study, pups in non-supplemented groups showed a normal serum retinol concentration but a marginal liver VA status. At all the time points, serum retinol concentration was significantly (P &lt; 0.05) increased in VA-supplemented groups as compared to non-supplemented ones; no significant difference was noted between the NFD and the HFD group. At P14, serum retinol concentration was significantly lower in the HFD + VA group than in the NFD + VA group. In liver, WAT, and BAT, both the concentration and the mass of total retinol was significantly higher in HFD + VA and NFD + VA group than in their respective control at all the time points, with no significant difference noted between the two control groups. At P25, both the concentration and the mass of total retinol in liver and in WAT was significantly higher in HFD + VA than in NFD + VA group.

Conclusions

Maternal VA supplementation added to both NFD and HFD raised VA status of the offspring. A lower VA concentration in serum but higher concentration in liver and WAT was observed in the HFD + VA group as compared to the NFD + VA group at given time points, indicating that maternal HFD consumption potentially compromised the availability of functional VA in circulation by increasing its deposition in storage organs.

Funding Sources

NIH.

ASSOCIATIONS BETWEEN COGNITIVE FUNCTION AND BIOACTIVE FOOD COMPOUNDS IN 100% WATERMELON JUICE

Objectives: Decline in cognitive function and increases in inflammation and oxidative stress are part of normal aging. Watermelon contains numerous bioactive compounds including lycopene, arginine, and citrulline that exhibit both anti-inflammatory and antioxidant functionality. Thus, the objective of this study was to examine the effect of 100% watermelon juice supplementation on cognitive performance. Methods: A placebo-controlled, randomized, double-blind, crossover trial was conducted with postmenopausal women (n = 16, 60 + 4.1y). Participants initiated a low-lycopene diet during a one-week run-in period and adhered to this diet throughout the study. For four weeks, participants were randomized to consume either two 360 mL servings of pasteurized 100% watermelon juice or a placebo beverage. Following a two-week washout period, participants received the opposite beverage for an additional four weeks. Pre/post each intervention arm, fasting blood samples were collected, and cognitive tests were administered to assess various neurocognitive domains. Statistical analyses included mixed models and Spearman correlations. Results: Serum lycopene exhibited a significant treatment effect (p=0.002); however, lycopene was not correlated with any cognitive test. In contrast, no significant treatment effect was observed for serum arginine or citrulline, yet arginine was significantly inversely correlated with Digit Span Forward (p = 0.005, r = -0.547) and Letter Fluency (p = 0.024, r = -0.507). Conclusion: Despite research supporting the relationship between lycopene and enhanced cognition, lycopene was not related to improvements in cognitive performance in this study. Nevertheless, consumption of 100% watermelon juice may be beneficial for increasing circulating levels of this antioxidant.

Effect of Acute Ingestion of Green Tea Extract and Lemon Juice on Oxidative Stress and Lipid Profile in Pigs Fed a High-Fat Diet

Green tea and its catechins have been shown to ameliorate high fat diet-induced oxidative stress and hyperlipidemia. However, low bioavailability of catechins limits their therapeutic potential. Lemon juice (LJ) has been suggested to enhance the bioavailability of catechins in vitro. This study investigated the antioxidative and hypolipidemic efficacy of a single dose of green tea extract (GTE) or GTE plus LJ (GTE + LJ) in high-fat diet fed pigs. Sixteen pigs ingested a single dose of GTE (190 mg/kg/day) or GTE + LJ (0.75 mL/kg/day) mixed with low-fat (LF; 5% fat) or high-fat (HF; 22% fat) diets and blood samples were collected for 24 h. Plasma catechin level peaked at two hours, and gradually returned to baseline after six hours following the intake. The addition of LJ significantly increased plasma catechin level. The diet containing GTE did not lower plasma cholesterol and triacylglycerol (TG) concentrations, superoxide dismutase (SOD) and catalase activity, or malondialdehyde concentration in 24 h in HF-fed pigs. Addition of a single dose of LJ, however, significantly decreased plasma TG level in LF groups but did not cause further changes on any other markers compared to the GTE alone. Our findings indicate limited effect of a single meal containing GTE on plasma antioxidant enzymes, lipid profile, and lipid peroxidation in pigs and no significant synergistic/additive action of adding LJ to GTE within 24 h in pigs. A study with a longer treatment period is warranted to further understand the potential role of GTE in reducing HF diet-induced oxidative stress and the possible synergistic role of LJ.

Watermelon Juice: a Novel Functional Food to Increase Circulating Lycopene in Older Adult Women

Because of accruing oxidative stress with advancing age, older adults may benefit from increased dietary intake of lycopene, a lipophilic carotenoid with potent antioxidant properties. Yet, intake of dietary lycopene as well as circulating lycopene levels are known to decrease with aging. Watermelon is one of the few food sources of dietary lycopene. Because heat treatment increases lycopene bioavailability, ingestion of watermelon in pasteurized juice form may be an optimal delivery vehicle to increase lycopene levels in older adults. However, due to its lipophilic nature, there are concerns that co-ingestion of dietary fat may be necessary for efficient intestinal absorption of lycopene. Thus, this feasibility study aimed to examine the effects of a one-time dose of 100% pasteurized watermelon juice on circulating lycopene concentrations of postmenopausal women after a 10-h overnight fast. Blood was sampled from eight women before and 2 h after ingestion of 360 ml of juice, and serum lycopene was measured by ultra-high performance liquid chromatography. Circulating lycopene levels increased by three-fold (p < 0.001) with increases observed for every participant. Results demonstrate that 100% watermelon juice is a palatable, effective means of increasing serum lycopene in older adult women, a group at risk for low carotenoid intake. Trial registration: Clinicaltrials.gov identifier: NCT03608254 .

Systemic and Adipose Tissue Redox Balance in Sprague-Dawley Rats Fed Standard Fat and High Fat Diets Supplemented with Lycopene (OR24-04-19)

Objectives

Dietary fat has been shown to enhance oxidative stress and adipose tissue (AT) accrual, further exacerbating redox imbalance. Lycopene is a potent lipophilic antioxidant with singlet oxygen quenching abilities. Thus, lycopene may mediate excess levels of oxidative stress imposed by a high fat diet. The purpose of this study was to evaluate systemic and AT redox balance in Sprague-Dawley rats fed lycopene-supplemented diets meeting and exceeding recommendations for fat intake in humans.

Methods

Male Sprague-Dawley rats (n = 18) at four weeks of age were fed 30% fat (control) or 60% fat purified diet (HFD) supplemented with 100 mg lycopene/d. Three rats in each diet group were euthanized at weeks 3, 7, and 10, respectively, with body weight and visceral AT weight recorded. Redox markers assessed included serum and AT lipid peroxides by the thiobarbituric acid-reactive substances (TBARS) assay and antioxidant capacity (AC) by the oxygen radical absorbance capacity assay. All statistical models were adjusted for dietary intake.

Results

At weeks 3 and 7, there were no significant differences in serum or AT redox markers or AT mass between the two groups; however, body weight was significantly lower in the HFD group at both time points (p = 0.016 and p = 0.008, respectively). At week 10, AT was significantly higher (p = 0.028) in the HFD group, yet there were no significant differences in lipid peroxides between the two groups. Of interest, AT in the HFD group exhibited significantly greater lipophilic AC (p = 0.031). Significant correlations between serum and AT TBARS (p = 0.036, r = 0.841) and serum and AT lycopene (p = 0.021, r = 0.879) were only observed at week 10.

Conclusions

Despite a 30% greater provision of dietary fat to the HFD group with subsequent AT accrual, no significant differences in systemic and AT oxidative stress measures were observed between the two groups at study completion; however, the HFD group exhibited increased lipophilic AC. Results suggest that lycopene may modulate systemic redox balance through the attenuation of AT oxidative stress.

Funding Sources

University of Alabama Pilot Grant.

Adipose Tissue Development and Metabolic Profile of Neonatal and Weanling Sprague-Dawley Rats in Response to a Maternal High Fat Diet Supplemented with Lycopene (P08-050-19)

Objectives

Excess adipose tissue (AT) may undergo adipocyte differentiation in response to nutritional stimuli. It is unknown if lycopene may metabolically activate adaptive thermogenesis and disrupt the ensuing dysfunction of an excessive energy burden. The purpose of this study was to assess AT development and metabolic profiles of Sprague-Dawley offspring from mothers fed high fat diets (HFD = 50% fat) supplemented with 1% lycopene during the suckling and post-weaning period.

Methods

Three Sprague-Dawley rats arrived on their 2nd day of gestation, and after three days of acclimation, mothers were randomized to a 25% normal-fat diet (NFD) or HFD. Upon delivery, one of the HFD mothers was transitioned to a HFD supplemented with 1% lycopene. Four pups/litter were euthanized at postnatal day 14 and 25 (P14 and P25, respectively) with body weight (BW) as well as the mass of visceral white AT (WAT) and brown AT (BAT) recorded. Serum samples from the P25 necropsy were analyzed for glucose, lipids, leptin, adiponectin, and inflammatory biomarkers. At P25, the remaining weanling pups (3 pups/litter) were fed the diets of their respective mothers until euthanizing at postnatal week 5 (P35).

Results

The HFD was effective in inducing weight gain as evidenced by increases in BW and WAT in the HFD group not receiving lycopene supplementation compared to pups from the NFD litter across all time points. At P14, WAT was 42.5% lower (P = 0.003) in rats reared by mothers consuming lycopene-supplemented HFD compared to the non-supplemented HFD group. At P25, significant decreases in WAT (P = 0.004, 25.6% lower) were also observed concomitantly with significant increases in BAT (P = 0.025, 40% increase) in rats reared by mothers consuming lycopene-supplemented HFD compared to the HFD group not receiving lycopene. Furthermore, at P25, glucose was 24% lower (P = 0.004) in the lycopene-supplemented HFD group. Albeit non-significant, BW and WAT in the lycopene-supplemented HFD group remained lower while BAT remained higher through P35.

Conclusions

Results suggest that lycopene may influence cardiometabolic outcomes such as accrual of AT mass and, subsequent obesity, as well as blood glucose dynamics. Additional research is warranted to determine diet-induced signaling pathways by which lycopene may influence adipocyte differentiation.

Funding Sources

NIH; University of Alabama Pilot Grant.

Maternal Vitamin a Supplementation Modulates Adipose Tissue Development in Offspring of Rats Consuming a High-Fat Diet (FS06-02-19)

Objectives

Vitamin A (VA) is a key regulator of obesity development and associated metabolic complications in adults. The aim of this study is to assess the impacts of VA supplementation during suckling and post-weaning periods on the adipose tissue (AT) development in rats reared by mothers consuming a high-fat diet (HFD).

Methods

Four Sprague-Dawley rats arrived on their 2nd day of gestation. After 3 days of acclimation, they were randomized to either a normal-fat diet (NFD = 25% fat) with adequate VA at 2.6 mg/kg (n = 2) or a HFD (50% fat) with the same amount of VA (n = 2). Upon delivery, pups were transferred to achieve a same number of n = 11/litter. Two mother rats, one from each group, were switched to a NFD and a HFD both with supplemented VA at 129 mg/kg (NFD + VA and HFD + VA), respectively. The other two remained on their diets with adequate VA through lactation (NFD and HFD). At postnatal day 14 (P14) and P25, 4 pups/litter were euthanized with body weight (BW), visceral white AT (WAT) mass, and brown AT (BAT) mass recorded. Serum samples from P25 necropsy were analyzed for glucose, lipids, leptin, adiponectin, and inflammatory biomarkers. At P25, the rest weanling pups (n = 3/group) were fed the diets as their respective mothers until they were euthanized at P35.

Results

At P14 and P25, the BW and WAT mass of pups in the HFD group were significantly (P < 0.05) higher than those in the NFD groups. Comparatively, these measures were significantly reduced in the HFD + VA group as compared to the HFD litter. A similar pattern of change in WAT mass was observed at P35. Additionally, at P25, the BAT mass of pups was significantly reduced by the maternal HFD, but VA supplement restored the level to that in the NFD groups. Serum analysis from P25 revealed a significantly higher adiponectin level in the HFD + VA group. In contrast, VA supplement showed a trend to reduce the glucose and leptin levels that were raised by the maternal HFD consumption.

Conclusions

Results support a regulatory role of VA supplementation during suckling and post-weaning period in the AT development in offspring from mothers consuming a HFD as evidenced by reduced BW and WAT mass, increased BAT mass, and modulation of adipokines. Future analysis will be conducted to study the mechanisms by which VA may impact the adipogenesis, WAT browning, and AT secretory functions.

Funding Sources

NIH.

Lycopene Protects Cortical Neurons via Oxidative Stress-mediated ΔN-Bcl-xL Formation (FS05-08-19)

Objectives

B-cell lymphoma-extra large (Bcl-xL) is a protein found in the mitochondrial membrane with anti-apoptotic properties. Bcl-xL has demonstrated neuroprotective effects by enhancing mitochondrial function. However, during oxidative stress, Bcl-xL undergoes cleavage to form pro-cell death ∆N-Bcl-xL. Accumulation of ∆N-Bcl-xL causes abnormal mitochondrial channel activity associated with neuronal death. Therefore, strategies that prevent formation of ∆N-Bcl-xL protect the brain. In this study, we hypothesize that cleavage of Bcl-xL can be controlled by nutritional intervention. We test if treatment with lycopene, a potent antioxidant with neuroprotective effects, can protect primary neurons via improving intracellular redox status by reducing production of ∆N-Bcl-xL.

Methods

Primary cortical neurons were treated with lycopene, hydrogen peroxide (a ROS donor), or both. Levels of superoxide, cell viability and cytotoxicity, and protein levels of Bcl-xL and ∆N-Bcl-xL were quantified.

Results

Hydrogen peroxide increased cytotoxicity while treatment with lycopene protected oxidative stress-induced cortical death. Lycopene prevented N-terminal cleavage of Bcl-xL and thus inhibited formation of ∆N-Bcl-xL.

Conclusions

These data show that the formation of ∆N-Bcl-xL is induced in part by reactive oxygen species and high levels of oxidative stress. The antioxidant properties of lycopene help reduce oxidative stress and prevent cleavage of Bcl-xL to ∆N-Bcl-xL, thus maintaining an anti-apoptotic environment.

Funding Sources

RG14811.

Intention of Older Women to Consume 100% Watermelon Juice for Vascular Health: An Application of Theory of Planned Behavior

To strengthen randomized controlled trials (RCT) evaluating the efficacy of 100% watermelon juice on vascular function of older women, theory-driven behavioral analysis as well as comparative sensory analysis of the intervention and placebo were conducted. The Theory of Planned Behavior was adopted to assess psychosocial determinants of intention to consume watermelon juice. Sensory attributes were assessed utilizing hedonic scales. Analysis included Structural Equation Modeling with maximum likelihood. The measurement model provided a good fit (x² = 70.22, df = 38; RMSEA = 0.07, CFI = 0.98; NFI = 0.95). Attitude (γ = 0.36), subjective norm (γ = 0.43), and perceived behavioral control (γ = 0.21,) were significant predictors (p < 0.001) of intention. Participants identified no significant differences in sensorial attributes between beverages, thereby minimizing sensory bias and discrimination. Similar approaches may help other RCT investigating novel foods and bioactive compounds bridge gaps between efficacy and effectiveness.

Modulating Oxidative Stress and Inflammation in Elders: The MOXIE Study

Cardiovascular disease (CVD) is the leading cause of death among women in the United States. Endothelial dysfunction and arterial stiffness increase with advancing age and are early predictors of future CVD outcomes. We designed the Modulating Oxidative Stress and Inflammation in Elders (MOXIE) study to examine the effects of 100% watermelon juice as a "food-first" intervention to reduce CVD risk among African American (AA) and European American (EA) women aged 55-69 years. Vascular dysfunction is more pronounced in AA compared to EA women due in part to lower nitric oxide bioavailability caused by higher oxidative stress. However, bioactive compounds in watermelon may improve vascular function by increasing nitric oxide bioavailability and antioxidant capacity. This trial will use a randomized, placebo-controlled, crossover design to investigate the potential of 100% watermelon juice to positively impact various robust measures of vascular function as well as serum biomarkers of oxidative stress and antioxidant capacity. This nutrition intervention and its unique methodology to examine both clinical and mechanistic outcomes are described in this article.