Elemental markers in elasmobranchs: effects of environmental history and growth on vertebral chemistry

Differences in the chemical composition of calcified skeletal structures (e.g. shells, otoliths) have proven useful for reconstructing the environmental history of many marine species. However, the extent to which ambient environmental conditions can be inferred from the elemental signatures within the vertebrae of elasmobranchs (sharks, skates, rays) has not been evaluated. To assess the relationship between water and vertebral elemental composition, we conducted two laboratory studies using round stingrays, Urobatis halleri, as a model species. First, we examined the effects of temperature (16°, 18°, 24°C) on vertebral elemental incorporation (Li/Ca, Mg/Ca, Mn/Ca, Zn/Ca, Sr/Ca, Ba/Ca). Second, we tested the relationship between water and subsequent vertebral elemental composition by manipulating dissolved barium concentrations (1x, 3x, 6x). We also evaluated the influence of natural variation in growth rate on elemental incorporation for both experiments. Finally, we examined the accuracy of classifying individuals to known environmental histories (temperature and barium treatments) using vertebral elemental composition. Temperature had strong, negative effects on the uptake of magnesium (D_Mg) and barium (D_Ba) and positively influenced manganese (D_Mn) incorporation. Temperature-dependent responses were not observed for lithium and strontium. Vertebral Ba/Ca was positively correlated with ambient Ba/Ca. Partition coefficients (D_Ba) revealed increased discrimination of barium in response to increased dissolved barium concentrations. There were no significant relationships between elemental incorporation and somatic growth or vertebral precipitation rates for any elements except Zn. Relationships between somatic growth rate and D_Zn were, however, inconsistent and inconclusive. Variation in the vertebral elemental signatures of U. halleri reliably distinguished individual rays from each treatment based on temperature (85%) and Ba exposure (96%) history. These results support the assumption that vertebral elemental composition reflects the environmental conditions during deposition and validates the use of vertebral elemental signatures as natural markers in an elasmobranch. Vertebral elemental analysis is a promising tool for the study of elasmobranch population structure, movement, and habitat use.

Abstract 160: Modulation of the serum metabolomic profiles of breast cancer patients after receiving limonene intervention

Background. Limonene is a bioactive food component found in citrus peel oil that has demonstrated chemopreventive and chemotherapeutic activities in preclinical studies. To better characterize its mechanism of action in the clinical setting, we measured the serum metabolomic profiles of breast cancer patients before and after receiving a short-term limonene intervention.

Methods. Forty women with stage 0 - II breast cancer received 2 g QD limonene daily for 2 - 6 weeks (21.5 ± 8.8 days) before surgical resection of their tumor. Pre/post intervention blood draws were taken to assess serum metabolomic profiles. Metabolomic analysis was performed on the gas chromatography mass spectrometry and liquid chromatography mass spectrometry platforms established at Metabolon, Inc.

Results. Of the 397 identified biochemicals, 71 changed significantly (p<0.05) from baseline to post limonene intervention. Pathway analysis revealed several key metabolic changes. Significant increases were noted in eight bile acid conjugates following limonene intervention, including a 3-fold elevation in taurocholate, taurodeoxycholate, and glycoursodeoxycholate. There were also significant decreases in a number of steroid hormones including dehydroisoandrosterone sulfate (DHEA-S), 4-androsten-3beta, 17beta-diol disulfate, epiandrosterone sulfate, androsterone sulfate, and pregnen-diol disulfate. In addition, markers of collagen remodeling or degradation were elevated following limonene intervention. Increased circulating vitamin C, improved insulin sensitivity and glycemic control, and reduced inflammatory potential were also noted following limonene treatment. An increase in plasma levels of ten different glycerophosphocholines and four carnitines were all significantly correlated to a decrease in cyclinD1 (all p's<0.01 and Rˆ2>0.4) in an exploratory analysis.

Conclusions. This global metabolomic profiling study revealed several novel mechanistic insights into the potential clinical activities of limonene. Efforts are ongoing to correlate these metabolic changes to carcinogenesis, clinical characteristics, and risk markers measured in breast tissue and serum.

Citation Format: Jessica A. Miller, Kirk Pappan, Chengcheng Hu, Elizabeth J. Want, Hector Keun, Julie E. Lang, H-H Sherry Chow. Modulation of the serum metabolomic profiles of breast cancer patients after receiving limonene intervention. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 160. doi:10.1158/1538-7445.AM2013-160

Expression of epidermal growth factor, transforming growth factor-β1 and adiponectin in nipple aspirate fluid and plasma of pre and post-menopausal women

BACKGROUND

Nipple aspirate fluid (NAF) contains large amounts of protein thought to reflect the microenvironment of the breast, and is of interest in breast cancer prevention research. The correlation between specific NAF proteins to plasma concentrations have not been well studied in healthy women. We collected matched NAF and plasma from 43 healthy pre and postmenopausal women participating in an early phase clinical study to compare the levels of putative cancer protein biomarkers. We compared baseline NAF and plasma levels of epidermal growth factor (EGF), transforming growth factor-beta 1 (TGF-β1), and adiponectin and evaluated menopausal status and body mass index (BMI) as potential modifying factors.

FINDINGS

NAF and plasma levels of EGF, TGF-β1 and adiponectin were not correlated. EGF and TGF-β1 levels in NAF of premenopausal women were significantly higher than postmenopausal women (P's < 0.01). These differences by menopausal status were not observed in plasma. Both NAF and plasma adiponectin levels were non-significantly higher in postmenopausal women. NAF biomarker levels were not associated with BMI whereas plasma EGF, TGF-β1 and adiponectin levels in postmenopausal women were all inversely correlated with BMI (P's < 0.05).

CONCLUSIONS

Protein biomarkers differ significantly between NAF and plasma and are affected differently by both BMI and menopausal status. This study demonstrates important differences in biological information gained by characterizing biomarkers in NAF compared to plasma and suggests each sample source may independently inform on breast cancer risk.

Human breast tissue disposition and bioactivity of limonene in women with early-stage breast cancer

Limonene is a bioactive food component found in citrus peel oil that has shown chemopreventive and chemotherapeutic activities in preclinical studies. We conducted an open-label pilot clinical study to determine the human breast tissue disposition of limonene and its associated bioactivity. We recruited 43 women with newly diagnosed operable breast cancer electing to undergo surgical excision to take 2 grams of limonene daily for two to six weeks before surgery. Blood and breast tissue were collected to determine drug/metabolite concentrations and limonene-induced changes in systemic and tissue biomarkers of breast cancer risk or carcinogenesis. Limonene was found to preferentially concentrate in the breast tissue, reaching high tissue concentration (mean = 41.3 μg/g tissue), whereas the major active circulating metabolite, perillic acid, did not concentrate in the breast tissue. Limonene intervention resulted in a 22% reduction in cyclin D1 expression (P = 0.002) in tumor tissue but minimal changes in tissue Ki67 and cleaved caspase-3 expression. No significant changes in serum leptin, adiponectin, TGF-β1, insulin-like growth factor binding protein-3 (IGFBP-3), and interleukin-6 (IL-6) levels were observed following limonene intervention. There was a small but statistically significant postintervention increase in insulin-like growth factor I (IGF-I) levels. We conclude that limonene distributed extensively to human breast tissue and reduced breast tumor cyclin D1 expression that may lead to cell-cycle arrest and reduced cell proliferation. Furthermore, placebo-controlled clinical trials and translational research are warranted to establish limonene's role for breast cancer prevention or treatment.

Efficacy of amitraz-impregnated collars on white-tailed deer (Artiodactyla: Cervidae) in reducing free-living populations of lone star ticks (Acari: Ixodidae)

Over a 7 yr period, we monitored the effect of a commercially available, amitraz impregnated anti-tick collar in controlling free-living populations of lone star ticks, Amblyomma americanum (L.) when manually fitted around necks of white-tailed deer, Odocoileus virginianus (Zimmermann). Study animals in treatment and control groups were confined in 38.8 ha game-fenced and densely vegetated treatment plots in South Texas. Tick densities during years 1 and 7 served as untreated pre- and posttreatment comparisons and treatments occurred during years 2 through 5. Reductions in tick densities in the treatment plot were compared against tick densities in a control plot having similar vegetation and numbers of untreated deer. During years of treatment, indices of control pressure ranged from 18.2 to 82.6 for nymphs and 16.9-78.7 for adults, and efficacy, expressed as percentage control during the final year of treatment, was 77.2 and 85.0%, respectively, for nymphal and adult ticks. These data show that acaricidal collar treatments provide efficacies very similar to those achieved with the existing ivermectin-medicated bait and '4-Poster' topical treatment technologies to control ticks feeding on wild white-tailed deer.

Efficacy of AR-R15896AR in the rat monofilament model of transient middle cerebral artery occlusion

The monofilament technique of transient middle cerebral artery occlusion (MCAO) was used in 3 separate studies to evaluate the efficacy of the low-affinity, use-dependent N-methyl-d-aspartate receptor antagonist, AR-R15896AR. First, a dose-response curve was attempted. Wister Kyoto rats received 2 hours of MCAO. Five minutes later, a 30-minute intravenous infusion of AR-R15896AR was given, followed by subcutaneous implantation of Alzet minipumps that were calibrated to maintain specified plasma levels (approximately 682, 1885, or 2682 ng/mL) of AR-R15896 (free base) for 1 week. The highest plasma level attained significantly decreased the percentage of damage to the subcortex, cortex, and total brain. Second, the high-dose, 1-week treatment regimen was repeated to determine if neuroprotection would extend to 8 weeks after MCAO. Indeed, in separate groups of animals, significant reduction in the percentage of damage, which was generally confined to the cortex and subcortex, was observed at 1, 2, 4, and 8 weeks. Third, verification was achieved in another laboratory. Lister Hooded rats received 60 minutes of transient MCAO. At 70 minutes, an acute dose of AR-R15896AR (20.3 mg/kg) was injected intraperitoneally and the rats were killed 23 hours later. This treatment group also exhibited significant reduction in the volume of infarction in the subcortex, cortex, and total brain. The outcome of these investigations supports the ongoing Phase II clinical trials in patients with acute stroke.

Multimodal hyperspectral imaging for the noninvasive diagnosis of cervical neoplasia

OBJECTIVE

To determine the ability of Multimodal Hyperspectral Imaging (MHI) to noninvasively detect, localize and diagnose cervical neoplasia.

MATERIALS AND METHODS

The cervical epithelium was interrogated by MHI using tissue fluorescence and reflectance measurements after the probe was placed on the ectocervix. A Papanicolaou smear was taken, and a colposcopic examination was performed and cervical histologic specimens were collected, when indicated. MHI and Pap smear sensitivity and specificity data were compared with colposcopic and histologic results.

RESULTS

Nineteen patients had CIN2 or higher, 30 had CIN1, 34 had benign cellular changes or metaplasia, and 28 were normal by both Pap smear and colposcopic examination. At equal specificity (70%) for both tests, the sensitivity of MHI was 97%, compared to 72% for the Pap smear.

CONCLUSION

MHI detected cervical cancer precursors at a rate greater than that obtained by a simultaneously collected Pap smear.

Abstract 3560: Application of metabolomics to assess serum profiles in limonene-treated breast cancer patients

Background. Limonene is a highly lipophilic monoterpene found in citrus peel that has demonstrated anticancer effects in preclinical models. Limonene likely affects multiple targets with varying potency. Advanced techniques to obtain metabolomic profiles from biofluids have the potential to provide a non-invasive means to assess these multiple effects. This strategy was applied to a clinical trial with women with early stage breast cancer receiving limonene treatment. Methods. Forty women with stage 0 - 2 breast cancer received 2 g QD limonene daily for 2 - 6 weeks (21.5 + 8.8 days) before scheduled surgical resection of their tumor. Pre/post intervention blood draws were taken for metabolomics analysis. Metabolomics profiling was conducted using ultra performance liquid chromatography tandem time-of-flight mass spectrometry (UPLC-QToF). Chromatographic separation was achieved using a gradient of two mobile phases; A: 0.1% formic acid in water, and B: 0.1% formic acid in methanol with a flow rate of 0.4 mL/min. A Waters Aquity UltraPerformance LC HSS T3 column was used. Metabolomics data was preprocessed with XCMS. Preliminary metabolite identification was conducted by mining the Human Metabolome Database (HMDB). Results. Over 1,000 metabolite features were identified by metabolomic profiling. In negative ion mode, three metabolites exhibited a 48-fold change or higher from pre to post-intervention; 183.1 m/z at 9.4 min, 177.0 m/z at 10.0 min, and 345.1 m/z 8.9 min (P's&lt;0.001). Two distinct peaks with m/z of 103.0 elute at 1.9 and 2.25 minutes respectively and changed &gt;20% (P's&lt;0.05). Twenty potential metabolites were identified in positive ion mode with &gt;20% change by the intervention (P's&lt; 0.05), of these, two exhibited 10-fold change or higher; 312.2 m/z at 8.7 min, and 369.2 m/z at 9.0 min (P's&lt;0.001). Discussion. This study demonstrates that 2 g QD daily oral limonene results in significant changes in approximately 20 metabolites in serum. Candidate compounds include limonene metabolites, carnitines and end products of arachindonic acid metabolism. Efforts are ongoing to identify these metabolites for analyte specific verification and quantitation. Further clinical trials with limonene are necessary to establish its potential role as a chemopreventive agent in breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3560. doi:1538-7445.AM2012-3560

Abstract 3558: A pilot clinical study of limonene in women with early stage breast cancer: Effects of short-term treatment on tissue limonene disposition and serum markers

Background: Limonene is a highly lipophilic monoterpene found in citrus peel oil that has demonstrated anticancer properties in preclinical studies. The purpose of this study was to evaluate whether limonene and its primary metabolite perillic acid (PA) would distribute extensively to the breast tissue and reach an effective drug concentration. Secondary endpoints included evaluation of changes in cancer-related biomarkers in plasma and tissue. Methods: Participants (N = 40) with newly diagnosed stage 0 - 2 breast cancer took 2 grams daily of oral limonene for 2 - 6 weeks (21.5 ± 8.8 days) prior to planned surgical tumor resection. Blood was drawn pre/post intervention for measurement of serum concentration of limonene, PA, and protein biomarkers, as well as to assess toxicity profiles. A small piece of breast tissue adjacent to the tumor mass was also collected for analysis of limonene and PA levels. Limonene and PA levels in tissue and serum were analyzed using specific chromatography-based assays. Results: Limonene was found to preferentially concentrate in breast tissue (332.3 + 336.1 uM) versus plasma (0.49 + 0.67 uM) with tissue-to-plasma concentration ratio (TPCR) of 1,667 + 312.5 (P&lt;0.001). PA did not concentrate in breast tissue (5.73 + 10.28 uM) versus plasma (3.89 + 6.81 uM) with TPCR of 1.4 + 0.56. Post-intervention serum levels of leptin, adiponectin, TGF-beta1, IGFBP-3 and IL-6 were unchanged from baseline. There was a small but statistically significant post-intervention increase in IGF-1, however the change was no longer significant after adjustment for number of days on agent. Possibly or probably related adverse events were primarily GI-related and were not dose-limiting. No clinically significant changes in complete blood count, renal, hepatic or other blood chemistry studies were noted. Analysis of the intervention effects on tissue biomarkers of proliferation, apoptosis, and cell cycle regulation is ongoing. Discussion: Oral limonene preferentially concentrates in the breast tissue and has a favorable side effect profile. PA does not readily concentrate in breast tissue when administered as oral limonene. Short-term limonene intervention resulted in minimal changes in systemic biomarkers. Further clinical trials with a longer intervention are necessary to establish limonene's potential role as a chemopreventive agent in breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3558. doi:1538-7445.AM2012-3558

Safety and Feasibility of Topical Application of Limonene as a Massage Oil to the Breast

BACKGROUND

Limonene, a major component in citrus oil, has demonstrated anti-cancer effects in preclinical mammary cancer models. However, the effective oral dose translates to a human dose that may not be feasible for chronic dosing. We proposed to evaluate topical application of limonene to the breast as an alternative dosing strategy.

MATERIALS AND METHODS

We conducted a mouse disposition study to determine whether limonene would be bio available in the mammary tissue after topical application. SKH-1 mice received topical or oral administration of limonene in the form of orange oil every day for 4 weeks. Plasma and mammary pads were collected 4 hrs after the final dosing. We also conducted an exploratory clinical study to evaluate the safety and feasibility of topically applied limonene in the form of orange oil to the breast. Healthy women were recruited to apply orange oil containing massage oil to their breasts daily for four weeks. Safety and feasibility were assessed by reported adverse events, clinical labs, and usage compliance. Pre and post-intervention nipple aspirate fluid (NAF) and plasma were collected for limonene concentration determination.

RESULTS

The mouse disposition study showed that topical and oral orange oil administration resulted in similar mammary tissue disposition of limonene with no clinical signs of toxicity. In the clinical study, the topical application of limonene containing massage oil to the breast was found to be safe with high levels of usage compliance for daily application, although NAF and plasma limonene concentrations were not significantly changed after the massage oil application.

CONCLUSIONS

Our studies showed that limonene is bio available in mammary tissue after topical orange oil application in mice and this novel route of administration to the breast is safe and feasible in healthy women.

P3-11-03: A Phase I Trial of D-Limonene in Newly Diagnosed Breast Cancer Patients: A Chemoprevention Study

Background: D-limonene (DL) is a highly lipophilic monoterpene found naturally in citrus that has been demonstrated in preclinical studies to have anticancer properties. Early phase clinical trials support the investigation of DL in the chemoprevention of breast cancer. We sought to evaluate whether DL and its presumed active metabolite perillic acid (PA) would distribute extensively to the breast tissue and reach an effective drug concentration. We hypothesized that the mechanism of DL is related to the induction of apoptosis in cancer cells.

Materials and Methods: We enrolled 40 patients with newly diagnosed Stage 0–2 breast cancer to take 2 grams daily of oral DL for 2–6 weeks prior to planned surgical intervention. Blood was drawn pre/post intervention to assess for toxicity and plasma concentration of DL and PA. Adverse effects related or possibly related to the study drug were noted. A small piece of breast tissue adjacent to the tumor mass was used to measure drug concentration for each patient. DL and PA levels in breast tissue were analyzed by gas chromatography and liquid chromatography, respectively, in tandem with mass spectrometry. Analysis of variance testing was used to determine if DL or PA preferentially concentrated in the breast tissue compared to plasma. We tested for a possible modulation of the biomarkers estrogen receptor (ER), progesterone receptor, HER2, Ki67 or grade pre/post treatment by comparing results from the core biopsy to the surgical pathology and applying pairwise Student's T tests. The caspase 3 and the annexin V assays were performed by plating 10,000 cells per well for the cell lines MCF7, MDA-231, BT474, and T47D and separately administering DL and PA acid in serial dilutions in their treatment concentration ranges in triplicate and read by microplate. Results: DL was found to preferentially concentrate in breast tissue versus plasma (tissue/plasma concentration ratio (TPCR) of 1297, p&lt;0.001) while PA did not concentrate (TPCR of 1.4, p=0.9). 20 patients (50%) reported Grade 1 eructation, which was the most common adverse effect. A slight decrease in white count from a mean of 7.1 to 6.6 (p=0.03) and a slight increase in ALT from a mean of 22.5 to 26.9 (p=0.03) were noted. No other statistically significant changes in laboratory values related to serum complete blood count, renal, hepatic or other studies were noted. No change in tissue biomarkers were noted post-treatment. DL produced a dose dependent increase in the apoptotic markers cleaved caspase 3 and annexin V for the ER positive cell lines MCF7, BT474, and T47D, however, no such response was noted for the triple negative cell line MDA-231. A PA dose response trend was noted with the annexin V but not the caspase 3 assay for each cell line.

Discussion: D-limonene preferentially concentrates in the breast tissue and is a candidate chemopreventive agent based on its favorable side effect profile. PA does not readily concentrate in the breast when administered as oral DL. Our correlative studies establish that DL induces apoptosis in ER positive breast cancer cell lines; no definite relationship between PA and apoptosis was found. Further clinical trials of DL are necessary to establish its potential role as a chemopreventive agent in breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-11-03.

d-Limonene: a bioactive food component from citrus and evidence for a potential role in breast cancer prevention and treatment

Although limited, observations from cell culture, animal, and epidemiological studies support the presence of anti-cancer properties in citrus peel and the primary bioactive food constituent, d-limonene. Early evidence from animal models suggests that when ingested, d-limonene exhibits a wide spectrum of biologic activity including chemotherapeutic and chemopreventive effects. In some of these early models, an analog of d-limonene, perillyl alcohol, demonstrated a more potent effect than d-limonene itself. Yet, when perillyl alcohol advanced to clinical trials, several trials were ended early due to doselimiting toxicities. Alternatively, oral d-limonene administration in humans is well tolerated even at high doses supporting its investigation as a potential bioactive for cancer prevention. Though the exact mechanisms of action of d-limonene are unclear, immune modulation and antiproliferative effects are commonly reported. Here, we review the pre-clinical evidence for d-limonene’s anticancer mechanisms, bioavailability, and safety, as well as the evidence for anti-cancer effects in humans, focusing on studies relevant to its use in the prevention and treatment of breast cancer.

Adipose tissue accumulation of d-limonene with the consumption of a lemonade preparation rich in d-limonene content

d-limonene is a bioactive food component found in high concentration in citrus peel oil with anticancer effects in preclinical studies of mammary carcinogenesis. Extrapolation of preclinical data to human cancer is limited, in part, by inadequate information on the oral bioavailability and tissue disposition of d-limonene in humans. As a fat-soluble compound, d-limonene is more likely to deposit in fatty tissues such as the breast. To assess disposition of d-limonene in humans, we conducted a pilot study of oral d-limonene-rich lemonade. Following a 1-wk washout period devoid of citrus, healthy adults consumed 40 oz. of freshly prepared lemonade containing 500 to 600 mg d-limonene daily for 4 wk. On the first and last consumption days, blood and buttock fat biopsy were collected. Matched preintervention and postintervention fat biopsies (n = 7), and matched preintervention and postintervention plasma samples (n = 6), were analyzed for d-limonene levels using gas chromatography and mass spectrometry. There was a significant increase in d-limonene levels in the fat biopsies after 4 wk (P = 0.009); initial levels ranged from nondetectable to 7.79 micromol/kg tissue, and postintervention levels ranged from 53.6 to 294 micromol/kg tissue. Plasma d-limonene levels increased from 0.35 to 0.72 micromol/l initially to postintervention levels of 0.54 to 1.65 micromol/l (P = 0.016). Postintervention adipose d-limonene levels were 51.0 to 195 times higher than plasma levels (P = 0.009). Our results demonstrate accumulation of d-limonene in adipose tissue after oral dosing and support additional studies of d-limonene for chemoprevention in tissues such as the breast that are comprised of a significant fat fraction.

Resveratrol modulates drug- and carcinogen-metabolizing enzymes in a healthy volunteer study

Resveratrol has been shown to exhibit cancer-preventive activities in preclinical studies. We conducted a clinical study to determine the effect of pharmacologic doses of resveratrol on drug- and carcinogen-metabolizing enzymes. Forty-two healthy volunteers underwent baseline assessment of cytochrome P450 (CYP) and phase II detoxification enzymes. CYP1A2, CYP2D6, CYP2C9, and CYP3A4 enzyme activities were measured by the metabolism of caffeine, dextromethorphan, losartan, and buspirone, respectively. Blood lymphocyte glutathione S-transferase (GST) activity and GST-pi level and serum total and direct bilirubin, a surrogate for UDP-glucuronosyl transferase (UGT) 1A1 activity, were measured to assess phase II enzymes. After the baseline evaluation, study participants took 1 g of resveratrol once daily for 4 weeks. Enzyme assessment was repeated upon intervention completion. Resveratrol intervention was found to inhibit the phenotypic indices of CYP3A4, CYP2D6, and CYP2C9 and to induce the phenotypic index of 1A2. Overall, GST and UGT1A1 activities were minimally affected by the intervention, although an induction of GST-pi level and UGT1A1 activity was observed in individuals with low baseline enzyme level/activity. We conclude that resveratrol can modulate enzyme systems involved in carcinogen activation and detoxification, which may be one mechanism by which resveratrol inhibits carcinogenesis. However, pharmacologic doses of resveratrol could potentially lead to increased adverse drug reactions or altered drug efficacy due to inhibition or induction of certain CYPs. Further clinical development of resveratrol for cancer prevention should consider evaluation of lower doses of resveratrol to minimize adverse metabolic drug interactions.

THE EFFECTS OF EXPOSURE TO COLD UPON EXPERIMENTAL INFECTION OF THE RESPIRATORY TRACT

1. Respiratory infection of rabbits with Bacillus bovisepticus (snuffles) is favored by chilling the animals after they have been accustomed to heat. 2. The character of this disease, which occurs frequently in rabbits under natural conditions, makes the application of the experimental results to similar respiratory conditions in man less open to objection than in similar experiments with other infections. 3. The weight of experimental evidence, including our own, does not justify the elimination of exposure to cold as a possible though secondary factor in the incidence of acute respiratory disease. 4. From the limited data of our last two experiments it is suggested that any marked change of temperature predisposes rabbits to this infection, the severity of which varies with the amount of change, and that a change from low to high temperature has an even more marked effect than that from high to low.

Abstract A57: High-dose resveratrol modulates drug and carcinogen metabolizing enzymes in a healthy volunteer study

Purpose: Resveratrol (RES) or 3, 4′, 5-trihydroxystilbene has been shown to inhibit carcinogenesis by affecting various molecular events in the initiation, promotion and progression stages. The cancer chemopreventive activity of RES has been demonstrated in vivo in a wide variety of tumors including skin, mammary, gastrointestinal, and liver cancer models. Modulation of Phase I and Phase II enzymes has been suggested to be one of the mechanisms responsible for the cancer preventive effect of RES. We conducted a clinical study to determine the effect of pharmacological doses of RES on drug and carcinogen metabolizing enzymes.

Methods: Forty-two healthy volunteers underwent baseline assessment of Phase I and Phase II enzymes. A cocktail of cytochrome P450 (CYP) metabolic probe drugs, including caffeine, dextromethorphan, losartan, and buspirone, were administered to assess the activity of CYP1A2, 2D6, 2C9, and 3A4, respectively. Blood and urine samples were collected for 8 hours after probe drug administration to determine parent probe drug and metabolite concentrations for measurements of CYP enzyme activities. Blood lymphocyte glutathione S-transferase (GST) activity and GST-π level, and serum total and direct bilirubin, a surrogate for UDP-glucuronosyl transferase (UGT) 1A1 activity, were measured to assess Phase II enzymes. After the baseline evaluation, study participants took 1 gm of RES once daily for 4 wks. Enzyme assessment was repeated upon intervention completion.

Results: RES intervention was found to suppress the activity of CYP3A4, 2D6, and 2C9. The geometric mean change of the activity index of CPY3A4, 2D6, and 2C9 was 33% (p = 0.01), 70% (p = 0.01), and 171% (p &lt; 0.0001), respectively. CYP1A2 activity was induced; the geometric mean change of the activity index was 16% (p = 0.005). The overall GST and UGT1A1 activity index were minimally affected by the intervention while an induction of GST-π level (84%, p = 0.002) and UGT1A1 activity index (20%, p = 0.0089) was observed in individuals with baseline enzyme level/activity in the lowest tertile.

Conclusion: We conclude that high doses of RES administration may modulate enzyme systems involved in carcinogen activation and detoxification, which may be one mechanism by which RES inhibits carcinogenesis. However, high doses of RES administration may lead to clinically relevant metabolic drug interactions. Further clinical studies are needed to determine whether lower doses of RES could be used to achieve cancer preventive activities. (Supported by N01CN35158 from the National Cancer Institute, Division of Cancer Prevention)

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A57.

Abstract A79: Human breast tissue bioavailability of topically applied limonene

Purpose: Limonene is a monocyclic monoterpene found at high concentration in citrus peel oil and has demonstrated anti-cancer effects in preclinical studies of mammary carcinogenesis. However, the effective oral dose determined in rodents extrapolates to a human dose that may not be feasible for long-term consumption. Limonene is highly lipophilic and has been long explored as an enhancer for percutaneous absorption of pharmaceutical drugs, including tamoxifen. Preliminary work from our group demonstrated that topically applied limonene is absorbed through the mouse skin and accumulates in the mammary glands.

Methods: We conducted a pilot clinical study to determine whether limonene would be bioavailable in the breast following topical application. In the first study phase, we recruited 19 healthy women to apply limonene containing massage oil to the breast daily or 3x/wk. Nipple aspirate fluid (NAF) and plasma samples were collected before and after 4 weeks of limonene massage application. Sample limonene concentrations were determined using gas chromatography-mass spectrometry. In the second study phase, we recruited 25 healthy women to undergo 4 weeks of daily limonene massage oil application to the breast. Potential agent effect biomarkers were determined in NAF and plasma collected before and after the limonene massage application.

Results: In samples collected from the first study phase, no significant increase in NAF and plasma limonene levels was observed following the limonene massage application, possibly because limonene deposits in the fatty breast tissue with minimal secretion to NAF or systemic circulation. Changes in agent effect biomarkers in NAF, including TGF-beta, EGF, and adiponectin, were evaluated in the second study phase for determination of the breast tissue limonene bioavailability. There were no consistent changes in the agent effect biomarkers overall or in pre-menopausal women following the limonene massage application. However, among the post-menopausal women (n =8), there were significant increases in NAF levels of TGF-beta (p = 0.005) and EGF (p = 0.032), and there was an increasing trend in adiponectin (p = 0.164, n=5 due to limited NAF volume).

Conclusions: We conclude that breast massage application of limonene containing massage oil did not result in consistent changes in limonene secretion to the NAF and the potential drug effect biomarkers in NAF. However, limonene massage application increased the NAF expression of TGF-beta and EGF in post-menopausal women, indicative of the intervention effects in the breast tissue. Further studies are needed to explore the potential effects of topical limonene massage intervention on carcinogenesis biomarkers in a larger cohort of post-menopausal women. Supported by Department of Defense, BCRP Idea Award, BC061529

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A79.

The effects of temperature and water concentration on the otolith incorporation of barium and manganese in black rockfish Sebastes melanops

Observations of multiple years of geographic variation in [Ba:Ca](otolith) and [Mn:Ca](otolith) in black rockfish Sebastes melanops prompted this study to examine the effects of temperature and water concentration on the otolith incorporation of Ba and Mn in this wholly marine species. The replicated experiment design consisted of two water temperatures (7.4 and 13.0 degrees C) and four water concentrations of Ba:Ca and Mn:Ca. A positive, linear relationship between [Ba:Ca](water) and [Ba:Ca](otolith) was observed at both temperatures. A positive temperature effect was also observed with mean partition coefficients for Ba (D(Ba)) greater in the 13 degrees C than in the 7.4 degrees C treatments (mean = 0.061 and 0.048, respectively). There was no relationship between [Mn:Ca](water) and [Mn:Ca](otolith) although a negative temperature effect was observed. Mean partition coefficients for Mn (D(Mn)) were lower in the 13 degrees C than in the 7.4 degrees C treatments (mean = 0.027 and 0.036, respectively). The data presented support the assumption of a positive, linear relationship between water and otolith Metal:Ca concentrations for Ba:Ca but not for Mn:Ca. Thus, although indicative of residence in distinct water masses, observed variation in [Metal:Ca](otolith) may not reflect variation in water concentration and can be affected by temperature. Caution should be applied in the interpretation of geographic variation of [Mn:Ca](otolith) until the mechanisms regulating its incorporation are more fully understood.

Efficacy of eprinomectin and doramectin against Amblyomma americanum (Acari: Ixodidae) on cattle

Steers were treated with doramectin or eprinomectin by daily oral capsule for 28 consecutive days. The level of doramectin in the serum of steers treated at 200 microg/kg/d reached a maximum of 104.0 +/- 22.1 ppb at day 21 and declined from 93.3 +/- 20.5 ppb on the final day of treatment to below detectable by day 56. Steers treated at 50 microg/kg/d reached a maximum level of doramectin in the serum of 24.7 +/- 1.2 ppb on day 21 and declined from 24.7 +/- 0.6 ppb on the final day of treatment to less than detectable on day 42. Both doramectin dosages provided 100% control of estimated larvae (EL) of Amblyomma americanum (L.) (Acari: Ixodidae) throughout the 28-d treatment period. Daily oral treatment with eprinomectin at a dosage of 200 microg/kg for 28 consecutive days produced a maximum concentration in the serum of 41.6 +/- 11.0 ppb at day 14. On the final day of eprinomectin treatment, the serum concentration was 38.3 +/- 5.9 ppb. Seven days later at day 35, eprinomectin was not detectable in the serum. For steers treated at 50 microg/kg/d for 28 consecutive days, the serum level of eprinomectin reached a maximum of 10.0 +/- 3.0 ppb on day 28 and was undetectable on day 35. Both eprinomectin dosages provided complete control of EL of A. americanum during the 28-d treatment period. Because eprinomectin is efficacious against A. americanum at lower serum levels in cattle and is eliminated from the serum at a more rapid rate than either doramectin or ivermectin, it provides advantages for use in applications such as the medicated bait for control of ticks on white-tailed deer and could have potential for use in the Cattle Fever Tick Eradication Program.

A sustained release gel formulation of doramectin for control of lone star ticks (Acari: Ixodidae) and horn flies (Diptera: Muscidae) on cattle

A gel formulation formed by incorporating technical doramectin into a 10% hydroxypropyl methylcellulose aqueous solution was used to subcutaneously inject steers at varying dosages. Doramectin serum concentration of steers receiving 600 microg (AI)/kg body weight declined from 21.9 ppb at 0.5 wk to below detectable at 8 wk postinjection. The 1,200 microg (AI)/kg injection resulted in serum concentrations of 29.1 ppb at 0.5 wk and declined to 0.5 ppb at 8 wk postinjection. Both the 600 and 1,200 microg (AI)/kg injections provided 100% inhibition of index of fecundity (IF) in adult lone star ticks, Amblyomma americanum L. (Acari: Ixodidae) through week 8, after which inhibition declined to 79.4 and 45.3%, respectively, during the 12th week posttreatment. For steers treated at 600 microg (AI)/kg, mortality of adult horn flies, Hematobia irritans L. (Diptera: Muscidae), declined from 16.9% during week 2 to 3.1% during week 7 postinjection. The blood from steers treated at 1,200 microg (AI)/kg resulted in a similar decline in mortality of blood fed adult horn flies from 29.4% during week 1 to 4.0% during week 7. The 600 microg (AI)/kg treatment provided complete control of larval horn flies in the manure for 9 wk, whereas the 1,200 microg (AI)/kg injection gave complete control for 14 wk posttreatment. The doramectin gel formulation provided long-lasting delivery of doramectin to cattle and extended control of lone star ticks and larval horn flies. Such a simple and inexpensive formulation could be useful in tick eradication programs by reducing the frequency of gathering cattle.

Reduced interference by gray squirrels with 4-poster deer treatment bait stations by using timed-release bait

When white-tailed deer, Odocoileus virginianus, feed on corn bait dispensed by 4-poster tick control devices, they rub against paint rollers impregnated with acaricide. Gray squirrels, Sciurus carolinensis, also feed on the corn bait in the feeding troughs of 4-posters, but in doing so, leave abundant corn fragments and meal that impede the flow of uneaten corn into the troughs. Large accumulations of fragments and meal adversely affect the operation of 4-posters and their use by deer. A battery-operated closure mechanism controlled by a photo sensor was developed to block the flow of corn into the troughs during the day when squirrels are active and deer infrequently visit 4-posters. The effectiveness of the diurnal corn restriction (DCR) concept and restriction mechanism was tested in a field trial at a tick-infested site in Maryland. DCR effectively eliminated accumulation of whole corn, partially eaten corn and corn meal in corn troughs associated with squirrel feeding. At the same time, deer usage of 4-posters was not diminished.

Determination of d-limonene in adipose tissue by gas chromatography-mass spectrometry

We developed a novel method for analyzing d-limonene levels in adipose tissue. Fat samples were subjected to saponification followed by solvent extraction. d-Limonene in the sample extract was analyzed using gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring. Linear calibration curves were established over the mass range of 79.0-2529 ng d-limonene per 0.1g of adipose tissue. Satisfactory within-day precision (R.S.D. 6.7-9.6%) and accuracy (%difference of -2.7 to 3.8%) and between-day precision (R.S.D. 6.0-10.7%) and accuracy (%difference of 1.8-2.6%) were achieved. The assay was successfully applied to human fat biopsy samples from a d-limonene feeding trial.

The effect of oral contraceptives on the nitric oxide system and renal function

We have demonstrated that oral contraceptive (OC) users exhibit elevated angiotensin II levels and angiotensin II type 1 receptor expression, indicative of renin-angiotensin system (RAS) activation, yet the renal and systemic consequences are minimal, suggesting that there is increased vasodilatory activity, counteracting the effect of RAS activation. We hypothesized that the nitric oxide (NO) system would be upregulated in OC users and that this would be reflected by a blunted hemodynamic response to l-arginine infusion. All subjects were studied after a 7-day controlled sodium and protein diet. Inulin and para-aminohippurate clearance techniques were used to assess renal function. l-Arginine was infused at 100, 250, and 500 mg/kg, each over 30 min. Skin endothelial NO synthase mRNA expression was assessed by real-time PCR. While OC nonusers exhibited significant increases in effective renal plasma flow (670.8 +/- 35.6 to 816.2 +/- 59.7 ml.min(-1).1.73 m(-2)) and glomerular filtration rate (133.4 +/- 4.3 to 151.0 +/- 5.7 ml.min(-1).1.73 m(-2), P = 0.04) and declines in renal vascular resistance (81.1 +/- 6.1 to 63.5 +/- 6.2 mmHg.ml(-1).min, P = 0.001) at the lower l-arginine infusion rates, the responses in OC users were blunted. While l-arginine reduced mean arterial pressure at the 250 and 500 mg/kg doses in OC nonusers, OC users only exhibited a decrease in mean arterial pressure at the highest infusion rate. In contrast, tissue endothelial NO synthase mRNA levels were higher in the OC users (P = 0.04). In summary, these findings suggest that the NO system is upregulated by OC use in young, healthy women. Increased activity of the NO pathway may modulate the hemodynamic effects of RAS activation in OC users.