George E. Rottinghaus

Resveratrol protects against global cerebral ischemic injury in gerbils

Increased oxidative stress has been implicated in the mechanisms of delayed neuronal cell death (DND) following cerebral ischemic insult. In this study, we investigated whether resveratrol, a polyphenolic antioxidant enriched in grape, may ameliorate ischemia-induced neuron cell death. Mongolian gerbils were divided into three groups, namely, sham control, ischemia and ischemia treated with resveratrol. Transient global cerebral ischemia was induced by occlusion of both common carotid arteries (CCA) for 5 min. Resveratrol was injected i.p. (30 mg/kg body weight), either during or shortly after CCA occlusion, and again at 24 h after ischemia. Cerebral blood flow was monitored before and during CCA occlusion using a laser Doppler flowmeter. Brain sections were immuno-stained for neurons, astrocytes and microglial cells. A time course study was also carried out to assess the bioavailability of resveratrol in serum, liver and brain using high performance liquid chromatography (HPLC). Morphometric measurements indicated extensive DND in the hippocampal CA1 region 4 days after ischemia and that neuron cell death was marked by the increase in reactive astrocytes and microglial cells. Administration of resveratrol, either during or after CCA occlusion, significantly (P<0.05) decreased DND as well as glial cell activation. Analysis of resveratrol after i.p. injection indicated its presence in serum, liver and brain with peak activity at 1, 4 and 4 h, respectively. This study demonstrated for the first time that resveratrol, a polyphenolic antioxidant, can cross the blood-brain barrier and exert protective effects against cerebral ischemic injury.

Similarity of bisphenol A pharmacokinetics in rhesus monkeys and mice: Relevance for human exposure

Objective Daily adult human exposure to bisphenol A (BPA) has been estimated at < 1 μg/kg, with virtually complete first-pass conjugation in the liver in primates but not in mice. We measured unconjugated and conjugated BPA levels in serum from adult female rhesus monkeys and adult female mice after oral administration of BPA and compared findings in mice and monkeys with prior published data in women. Methods Eleven adult female rhesus macaques were fed 400 μg/kg deuterated BPA (dBPA) daily for 7 days. Levels of serum dBPA were analyzed by isotope-dilution liquid chromatography–mass spectrometry (0.2 ng/mL limit of quantitation) over 24 hr on day 1 and on day 7. The same dose of BPA was fed to adult female CD-1 mice; other female mice were administered 3H-BPA at doses ranging from 2 to 100,000 μg/kg. Results In monkeys, the maximum unconjugated serum dBPA concentration of 4 ng/mL was reached 1 hr after feeding and declined to low levels by 24 hr, with no significant bioaccumulation after seven daily doses. Mice and monkeys cleared unconjugated serum BPA at virtually identical rates. We observed a linear (proportional) relationship between administered dose and serum BPA in mice. Conclusions BPA pharmacokinetics in women, female monkeys, and mice is very similar. By comparison with approximately 2 ng/mL unconjugated serum BPA reported in multiple human studies, the average 24-hr unconjugated serum BPA concentration of 0.5 ng/mL in both monkeys and mice after a 400 μg/kg oral dose suggests that total daily human exposure is via multiple routes and is much higher than previously assumed.

Neuroprotective mechanisms of curcumin against cerebral ischemia-induced neuronal apoptosis and behavioral deficits.

Increased oxidative stress has been regarded as an important underlying cause for neuronal damage induced by cerebral ischemia/reperfusion (I/R) injury. In recent years, there has been increasing interest in investigating polyphenols from botanical source for possible neuroprotective effects against neurodegenerative diseases. In this study, we investigated the mechanisms underlying the neuroprotective effects of curcumin, a potent polyphenol antioxidant enriched in tumeric. Global cerebral ischemia was induced in Mongolian gerbils by transient occlusion of the common carotid arteries. Histochemical analysis indicated extensive neuronal death together with increased reactive astrocytes and microglial cells in the hippocampal CA1 area at 4 days after I/R. These ischemic changes were preceded by a rapid increase in lipid peroxidation and followed by decrease in mitochondrial membrane potential, increased cytochrome c release, and subsequently caspase‐3 activation and apoptosis. Administration of curcumin by i.p. injections (30 mg/kg body wt) or by supplementation to the AIN76 diet (2.0 g/kg diet) for 2 months significantly attenuated ischemia‐induced neuronal death as well as glial activation. Curcumin administration also decreased lipid peroxidation, mitochondrial dysfunction, and the apoptotic indices. The biochemical changes resulting from curcumin also correlated well with its ability to ameliorate the changes in locomotor activity induced by I/R. Bioavailability study indicated a rapid increase in curcumin in plasma and brain within 1 hr after treatment. Together, these findings attribute the neuroprotective effect of curcumin against I/R‐induced neuronal damage to its antioxidant capacity in reducing oxidative stress and the signaling cascade leading to apoptotic cell death.

Fumonisin toxicity in broiler chicks

The effects of dietary fumonisin B1 were evaluated in young broiler chicks. The experimental design consisted of 5 treatments each with 9 randomly allotted male broiler chicks. Day-old chicks were fed diets containing 0 (feed control), 100, 200, 300, or 400 mg fumonisin B1/kg feed for 21 days. Response variables measured were chick performance, organ weights, serum biochemistry, and histologic parameters. Body weights and average daily gain dramatically decreased with increasing dietary fumonisin B1, and liver, proventriculus, and gizzard weights increased. Diarrhea, thymic cortical atrophy, multifocal hepatic necrosis, biliary hyperplasia, and rickets were present in chicks fed diets containing fumonisin B,. Serum calcium, cholesterol, and aspartate aminotransferase levels all increased at higher fumonisin dietary levels. Results indicate that fumonisin, from Fusarium moniliforme culture material, is toxic in young chicks.

Resveratrol protects against neurotoxicity induced by kainic acid.

Increased oxidative stress has been implicated in the mechanisms of excitotoxicity in hippocampus induced by kainic acid (KA), an excitatory glutamate receptor agonist. Resveratrol, a polyphenolic antioxidant compound enriched in grape, is regarded as an important ingredient in red wine to offer cardiovascular and neural protective effects. This study was designed to investigate whether resveratrol treatment may ameliorate neuronal death after KA administration. Adult Sprague Dawley male rats were treated with KA (8 mg/kg) daily for 5 days and another group was treated similarly with KA plus resveratrol (30 mg/kg/day). Three hr after the last treatment protocol, animals were sacrificed, and brain sections were obtained for histochemical and immunohistochemical identification of neurons, astrocytes and microglial cells. After KA administration, significant neuronal death and activation of astrocytes and microglial cells were observed in the hippocampal CA1, CA3 and polymorphic layer (hilar) of the dentate gyrus (DG) (P < 0.001). The KA-induced hippocampal neuronal damage was significantly attenuated by treatment with resveratrol (P < 0.001). Resveratrol also suppressed KA-induced activation of astrocytes and microglial cells. Since increased oxidative stress is a key factor for KA-induced neurotoxicity, this study demonstrated the ability of resveratrol to act as free radical scavenger to protect against neuronal damage caused by excitotoxic insults.

Effects of turmeric (Curcuma longa) on the expression of hepatic genes associated with biotransformation, antioxidant, and immune systems in broiler chicks fed aflatoxin

The objective of the present study was to evaluate the efficacy of curcumin, an antioxidant found in turmeric (Curcuma longa) powder (TMP), to ameliorate changes in gene expression in the livers of broiler chicks fed aflatoxin B(1) (AFB(1)). Four pen replicates of 5 chicks each were assigned to each of 4 dietary treatments, which included the following: A) basal diet containing no AFB(1) or TMP (control), B) basal diet supplemented with TMP (0.5%) that supplied 74 mg/kg of curcumin, C) basal diet supplemented with 1.0 mg of AFB(1)/kg of diet, and D) basal diet supplemented with TMP that supplied 74 mg/kg of curcumin and 1.0 mg of AFB(1)/kg of diet. Aflatoxin reduced (P < 0.05) feed intake and BW gain and increased (P < 0.05) relative liver weight. Addition of TMP to the AFB(1) diet ameliorated (P < 0.05) the negative effects of AFB(1) on growth performance and liver weight. At the end of the 3-wk treatment period, livers were collected (6 per treatment) to evaluate changes in the expression of genes involved in antioxidant function [catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST)], biotransformation [epoxide hydrolase (EH), cytochrome P450 1A1 and 2H1 (CYP1A1 and CYP2H1)], and the immune system [interleukins 6 and 2 (IL-6 and IL-2)]. Changes in gene expression were determined using the quantitative real-time PCR technique. There was no statistical difference in gene expression among the 4 treatment groups for CAT and IL-2 genes. Decreased expression of SOD, GST, and EH genes due to AFB(1) was alleviated by inclusion of TMP in the diet. Increased expression of IL-6, CYP1A1 and CYP2H1 genes due to AFB(1) was also alleviated by TMP. The current study demonstrates partial protective effects of TMP on changes in expression of antioxidant, biotransformation, and immune system genes in livers of chicks fed AFB(1). Practical application of the research is supplementation of TMP in diets to prevent or reduce the effects of aflatoxin in chicks fed aflatoxin-contaminated diets.

Soy Isoflavones Have an Antiestrogenic Effect and Alter Mammary Promoter Hypermethylation in Healthy Premenopausal Women

We determined if soy isoflavones have dose-related estrogenic and methylation effects. Thirty-four healthy premenopausal women were randomized to 40 mg or 140 mg isoflavones daily through one menstrual cycle. Breast specific and systemic estrogenic effects were assessed measuring the estrogenic marker complement (C)3 and changes in cytology, whereas methylation assessment of 5 cancer related genes (p16, RASSF1A, RAR β 2, ER, and CCND2) was performed on intraductal specimens. Serum genistein significantly increased after consuming both isoflavone doses. Cytology did not significantly change at either isoflavone dose. Serum C3 levels posttreatment were inversely related to change in serum genistein ( r =–0.76, P = 0.0045) in women consuming low but not high dose isoflavones. The RAR β 2 hypermethylation increase posttreatment correlated with the posttreatment genistein level considering the entire group ( r = 0.67, P = 0.0017) and those receiving high-dose isoflavones ( r = 0.68, P = 0.021). At the low but not the high isoflavone dose, CCND2 hypermethylation increase correlated with posttreatment genistein levels ( r = 0.79, P = 0.011). In summary, the inverse correlation between C3 and genistein suggests an antiestrogenic effect. Isoflavones induced dose-specific changes in RAR β 2 and CCND2 gene methylation, which correlated with genistein levels. This work provides novel insights into estrogenic and methylation effects of dietary isoflavones.

Efficacy of Turmeric (Curcuma longa), Containing a Known Level of Curcumin, and a Hydrated Sodium Calcium Aluminosilicate to Ameliorate the Adverse Effects of Aflatoxin in Broiler Chicks

A 3-wk feeding study was conducted to evaluate the efficacy of turmeric (Curcuma longa) powder (TMP), containing a known level of curcumin, and a hydrated sodium calcium aluminosilicate (HSCAS; Improved Milbond-TX, IMTX, an adsorbent, Milwhite Inc., Houston, TX) to ameliorate the adverse effects of aflatoxin B(1) (AFB(1)) in broiler chicks. Four pen replicates of 5 chicks each were assigned to each of 7 dietary treatments, which included the basal diet not containing TMP, HSCAS, or AFB(1) (control); basal diet supplemented with 0.5% food grade TMP that contained 1.48% total curcuminoids (74 mg/kg); basal diet supplemented with 0.5% HSCAS; basal diet supplemented with 1.0 mg/kg AFB(1); basal diet supplemented with 0.5% TMP and 1.0 mg/kg AFB(1); basal diet supplemented with 0.5% HSCAS and 1.0 mg/kgAFB(1); and basal diet supplemented with 0.5% TMP, 0.5% HSCAS, and 1.0 mg/kg AFB(1). The addition of TMP to the AFB(1) diet significantly (P < 0.05) improved the weight gain of chicks, and the addition of HSCAS to the AFB(1) diet significantly (P < 0.05) improved feed intake and weight gain, and reduced relative liver weight. The addition of TMP or HSCAS and TMP with HSCAS ameliorated the adverse effects of AFB(1) on some of the serum chemistry parameters (total protein, albumin, cholesterol, calcium). Further, decreased antioxidant functions in terms of level of peroxides, superoxide dismutase activity, and total antioxidant concentration in liver homogenate due to AFB1 were also alleviated by the inclusion of TMP, HSCAS, or both. The reduction in the severity of hepatic microscopic lesions due to supplementation of the AFB(1) diet with TMP and HSCAS demonstrated the protective action of the antioxidant and adsorbent used in the present study.

Fumonisin Mycotoxicosis in Broilers: Performance and Pathology

Fusarium moniliforme culture material containing fumonisin B1 at 300 mg/kg was incorporated into a broiler starter ration and fed ad libitum to 1-day-old broiler chicks for 2 weeks in two experiments. Clinical features of the disease produced included diarrhea, a 19% reduction in body weight, a 30% increase in relative liver weight, and a worsening of feed conversion by 20 points at 2 weeks of age. Histologically, chicks fed fumonisin had multifocal hepatic necrosis, biliary hyperplasia, muscle necrosis, intestinal goblet-cell hyperplasia, and rickets. Simultaneous feeding of 0.5% aluminosilicate had no effect on the clinical disease or lesions. The clinical disease and lesions induced mimicked those of a viral enteritis.

Surfactant modified zeolites--new efficient adsorbents for mycotoxins

The in vitro mycotoxins adsorption by natural clinoptilolite––heulandite rich tuff modified with different amounts of octadecyldimethyl benzyl ammonium chloride (Do) and dioctadecyldimethyl ammonium chloride (Pr) was investigated. Two methods of preparation of the organo-zeolites (OZs) were used––wet process (activation in suspension) and dry process (tribochemical process). The chemical stability of the two organically modified zeolites (OZs) obtained by wet and dry processes was investigated after an electrolyte treatment at pH 1, 7 and 10 by thermal (DTA/DDTA/TG) analysis and IR spectroscopy. Results of IR and thermal analysis, after electrolyte treatment, confirm that OZs obtained by wet and dry processes are completely stable in the investigated pH region. Mycotoxin binding studies showed that all the OZs effectively adsorbed aflatoxin B1, zearalenone, ochratoxin A and the ergopeptine alkaloids. The method of preparation of the OZs had no influence on adsorption of mycotoxins. The non-linear shape of the mycotoxin adsorption isotherms of OZs suggests that modification of zeolitic tuff with long chain organic cation Pr, by both wet and dry processes of preparation, formed the same specific active sites which are relevant for adsorption of aflatoxin B1, zearalenone and ochratoxin A by OZs.