Ginsenoside Rc from Panax Ginseng Ameliorates Palmitate-Induced UB/OC-2 Cochlear Cell Injury.

By 2050, at least 700 million people will require hearing therapy while 2.5 billion are projected to suffer from hearing loss. Sensorineural hearing loss (SNHL) arises from the inability of the inner ear to convert fluid waves into neural electric signals because of injury to cochlear hair cells that has resulted in their death. In addition, systemic chronic inflammation implicated in other pathologies may exacerbate cell death leading to SNHL. Phytochemicals have emerged as a possible solution because of the growing evidence of their anti-inflammatory, antioxidant, and anti-apoptotic properties. Ginseng and its bioactive molecules, ginsenosides, exhibit effects that suppress pro-inflammatory signaling and protect against apoptosis. In the current study, we investigated the effects of ginsenoside Rc (G-Rc) on UB/OC-2 primary murine sensory hair cell survival in response to palmitate-induced injury. G-Rc promoted UB/OC-2 cell survival and cell cycle progression. Additionally, G-Rc enhanced the differentiation of UB/OC-2 cells into functional sensory hair cells and alleviated palmitate-induced inflammation, endoplasmic reticulum stress, and apoptosis. The current study offers novel insights into the effects of G-Rc as a potential adjuvant for SNHL and warrants further studies elucidating the molecular mechanisms.

Zyflamend induces apoptosis in pancreatic cancer cells via modulation of the JNK pathway.

BACKGROUND: Current pharmacological therapies and treatments targeting pancreatic neuroendocrine tumors (PNETs) have proven ineffective, far too often. Therefore, there is an urgent need for alternative therapeutic approaches. Zyflamend, a combination of anti-inflammatory herbal extracts, that has proven to be effective in various in vitro and in vivo cancer platforms, shows promise. However, its effects on pancreatic cancer, in particular, remain largely unexplored. METHODS: In the current study, we investigated the effects of Zyflamend on the survival of beta-TC-6 pancreatic insulinoma cells (ß-TC6) and conducted a detailed analysis of the underlying molecular mechanisms. RESULTS: Herein, we demonstrate that Zyflamend treatment decreased cell proliferation in a dose-dependent manner, concomitant with increased apoptotic cell death and cell cycle arrest at the G2/M phase. At the molecular level, treatment with Zyflamend led to the induction of ER stress, autophagy, and the activation of c-Jun N-terminal kinase (JNK) pathway. Notably, pharmacological inhibition of JNK abrogated the pro-apoptotic effects of Zyflamend. Furthermore, Zyflamend exacerbated the effects of streptozotocin and adriamycin-induced ER stress, autophagy, and apoptosis. CONCLUSION: The current study identifies Zyflamend as a potential novel adjuvant in the treatment of pancreatic cancer via modulation of the JNK pathway. Video abstract.

Concurrent regulation of LKB1 and CaMKK2 in the activation of AMPK in castrate-resistant prostate cancer by a well-defined polyherbal mixture with anticancer properties.

BACKGROUND: Zyflamend, a blend of herbal extracts, effectively inhibits tumor growth using preclinical models of castrate-resistant prostate cancer mediated in part by 5'-adenosine monophosphate-activated protein kinase (AMPK), a master energy sensor of the cell. Clinically, treatment with Zyflamend and/or metformin (activators of AMPK) had benefits in castrate-resistant prostate cancer patients who no longer responded to treatment. Two predominant upstream kinases are known to activate AMPK: liver kinase B1 (LKB1), a tumor suppressor, and calcium-calmodulin kinase kinase-2 (CaMKK2), a tumor promotor over-expressed in many cancers. The objective was to interrogate how Zyflamend activates AMPK by determining the roles of LKB1 and CaMKK2. METHODS: AMPK activation was determined in CWR22Rv1 cells treated with a variety of inhibitors of LKB1 and CaMKK2 in the presence and absence of Zyflamend, and in LKB1-null HeLa cells that constitutively express CaMKK2, following transfection with wild type LKB1 or catalytically-dead mutants. Upstream regulation by Zyflamend of LKB1 and CaMKK2 was investigated targeting protein kinase C-zeta (PKCζ) and death-associated protein kinase (DAPK), respectively. RESULTS: Zyflamend's activation of AMPK appears to be LKB1 dependent, while simultaneously inhibiting CaMKK2 activity. Zyflamend failed to rescue the activation of AMPK in the presence of pharmacological and molecular inhibitors of LKB1, an effect not observed in the presence of inhibitors of CaMKK2. Using LKB1-null and catalytically-dead LKB1-transfected HeLa cells that constitutively express CaMKK2, ionomycin (activator of CaMKK2) increased phosphorylation of AMPK, but Zyflamend only had an effect in cells transfected with wild type LKB1. Zyflamend appears to inhibit CaMKK2 by DAPK-mediated phosphorylation of CaMKK2 at Ser511, an effect prevented by a DAPK inhibitor. Alternatively, Zyflamend mediates LKB1 activation via increased phosphorylation of PKCζ, where it induced translocation of PKCζ and LKB1 to their respective active compartments in HeLa cells following treatment. Altering the catalytic activity of LKB1 did not alter this translocation. DISCUSSION: Zyflamend's activation of AMPK is mediated by LKB1, possibly via PKCζ, but independent of CaMKK2 by a mechanism that appears to involve DAPK. CONCLUSIONS: Therefore, this is the first evidence that natural products simultaneously and antithetically regulate upstream kinases, known to be involved in cancer, via the activation of AMPK.

Characterization of the Pro-Inflammatory Cytokine IL-1ß on Butyrate Oxidation in Colorectal Cancer Cells.

Cancer, in part, is driven, by alterations in cellular metabolism that promote cell survival and cell proliferation. Identifying factors that influence this shift in cellular metabolism in cancer cells is important. Interleukin-1ß (IL-1ß) is a pro-inflammatory cytokine that has been reported to be elevated in colorectal cancer patients. While much is known toward the effect of dietary nutrients on regulating inflammation and the inflammatory response, which includes cytokines such as IL-1ß, far less is understood how cytokines impact nutrient fate to alter cancer cell metabolism. Butyrate, a nutrient derived from the fermentation of dietary fiber in the colon, is the preferential exogenous energetic substrate used by non-cancerous colonocytes, but is used less efficiently by colorectal cancer cells. To test whether IL-1ß alters colonocyte energy metabolism, we measured butyrate oxidation in HCT116 colorectal cancer cells with and without IL-1ß. We hypothesize that IL-1ß will push cancerous colonocytes away from the utilization and oxidation of butyrate. In this study, we demonstrate that pretreatment of colorectal cancer cells with IL-1ß diminished butyrate oxidation and NADH levels. This effect was blocked with the interleukin receptor antagonist A (IL-1RA). Moreover, IL-1ß suppressed basal mitochondrial respiration and lowered the mitochondrial spare capacity. By using inhibitors to block downstream targets of the interleukin-1 receptor pathway, we show that p38 is required for the IL-1ß-mediated decrease in butyrate oxidation. These data provide insight into the metabolic effects induced by IL-1ß in colorectal cancer, and identify relevant targets that may be exploited to block the effects of this cytokine. J. Cell. Biochem. 118: 1614-1621, 2017. © 2016 Wiley Periodicals, Inc.

Cellular Metabolism and Dose Reveal Carnitine-Dependent and -Independent Mechanisms of Butyrate Oxidation in Colorectal Cancer Cells.

Dietary fiber has been suggested to suppress colorectal cancer development, although the mechanisms contributing to this beneficial effect remain elusive. Butyrate, a fermentation product of fiber, has been shown to have anti-proliferative and pro-apoptotic effects on colorectal cancer cells. The metabolic fate of butyrate in the cell is important in determining whether, it acts as an HDAC inhibitor or is consumed as a short-chain fatty acid. Non-cancerous colonocytes utilize butyrate as the primary energy source whereas cancerous colonocytes increase glucose utilization through the Warburg effect. In this study, we show that butyrate oxidation is decreased in cancerous colonocytes compared to non-cancerous colonocytes. We demonstrate that colorectal cancer cells utilize both a carnitine-dependent and carnitine-independent mechanism that contributes to butyrate oxidation. The carnitine-dependent mechanism is contingent on butyrate concentration. Knockdown of CPT1A in colorectal cancer cells abolishes butyrate oxidation. In terms of selectivity, the carnitine-dependent mechanism only regulated butyrate oxidation, as acetate and propionate oxidation were carnitine-independent. Carnitine decreased the action of butyrate as an HDAC inhibitor and suppressed induction of H3 acetylation by butyrate in colorectal cancer cells. Thus, diminished oxidation of butyrate is associated with decreased HDAC inhibition and histone acetylation. In relation to the mechanism, we find that dichloroacetate, which decreases phosphorylation of pyruvate dehydrogenase, increased butyrate oxidation and that this effect was carnitine-dependent. In conclusion, these data suggest that colorectal cancer cells decrease butyrate oxidation through inhibition of pyruvate dehydrogenase, which is carnitine-dependent, and provide insight into why butyrate shows selective effects toward colorectal cancer cells. J. Cell. Physiol. 231: 1804-1813, 2016. © 2015 Wiley Periodicals, Inc.

Omega-3 Fatty Acid Consumption and Prostate Cancer: A Review of Exposure Measures and Results of Epidemiological Studies.

Animal studies have shown that dietary omega-3 polyunsaturated fatty acids (n-3) may play a role in the development of prostate cancer, but the results of epidemiologic studies have been equivocal. Associations in humans may vary depending on study design, measurement methodology of fatty acid intake, intake ranges, and stage of cancer development. To address this, we identified 36 published studies through PubMed (Medline) from 1993 through 2013 on long-chain n-3s and prostate cancer. Exposure measurements included dietary assessment and biomarker levels. Associations for total, early, and late stage prostate cancer were examined by subgroup of study design and exposure measure type and by using forest plots to illustrate the relative strength of associations within each subgroup. We also tested for potential threshold effects by considering studies that included measurement cut-points that met intake levels recommended by the American Heart Association. We found no consistent evidence supporting a role of n-3s in either the causation or prevention of prostate cancer at any stage or grade. Results did not vary appreciably by study design, exposure measurement, intake level, or stage of cancer development.

Zyflamend, a polyherbal mixture, down regulates class I and class II histone deacetylases and increases p21 levels in castrate-resistant prostate cancer cells.

BACKGROUND: Zyflamend, a mixture containing extracts of ten herbs, has shown promise in a variety of preclinical cancer models, including prostate cancer. The current experiments were designed to investigate the effects of Zyflamend on the expression of class I and II histone deacetylases, a family of enzymes known to be over expressed in a variety of cancers. METHODS: CWR22Rv1 cells, a castrate-resistant prostate cancer cell line, were treated with Zyflamend and the expression of class I and II histone deacetylases, along with their downstream target the tumor suppressor gene p21, was investigated. Involvement of p21 was confirmed with siRNA knockdown and over expression experiments. RESULTS: Zyflamend down-regulated the expression of all class I and II histone deacetylases where Chinese goldthread and baikal skullcap (two of its components) appear to be primarily responsible for these results. In addition, Zyflamend up regulated the histone acetyl transferase complex CBP/p300, potentially contributing to the increase in histone 3 acetylation. Expression of the tumor suppressor gene p21, a known downstream target of histone deacetylases and CBP/p300, was increased by Zyflamend treatment and the effect on p21 was, in part, mediated through Erk1/2. Knockdown of p21 with siRNA technology attenuated Zyflamend-induced growth inhibition. Over expression of p21 inhibited cell growth and concomitant treatment with Zyflamend enhanced this effect. CONCLUSIONS: Our results suggest that the extracts of this polyherbal combination increase histone 3 acetylation, inhibit the expression of class I and class II histone deacetylases, increase the activation of CBP/p300 and inhibit cell proliferation, in part, by up regulating p21 expression.

Activation of nucleotide oligomerization domain containing protein 1 induces lipolysis through NF-κB and the lipolytic PKA activation in 3T3-L1 adipocytes.

Obesity is associated with chronic inflammation. Toll-like receptors (TLR) and NOD-like receptors (NLR) are two families of pattern recognition receptors that play important roles in the immune response and inflammation in adipocytes. Activation of TLR4 has been shown to stimulate lipolysis from adipose tissue or adipocytes. However, effects of activation of nucleotide-oligomerization domain containing protein 1 (NOD1), one of the prominent members of NLRs, on adipocyte lipolysis have not been studied. Here we report that NOD1 activation by the synthetic ligands (Tri-DAP and C12-iEDAP) stimulated lipolysis in 3T3-L1 adipocytes in a time- and dose-dependent manner. C12-iEDAP-induced lipolysis was attenuated with NOD1 siRNA knockdown, demonstrating the specificity of the effects. Moreover, inhibition of the protein kinase A (PKA)/hormone sensitive lipase (HSL) and NF-κB pathways by the pharmacological inhibitors attenuated the lipolytic effects of C12-iEDAP. Furthermore, we show NOD1 activation induced PKA activation independent of cAMP production and inhibition of NF-κB pathways attenuated phosphorylation of selected PKA lipolytic targets (phosphorylation of Perilipin Ser 517 and HSL Ser 563). Taken together, our results demonstrate a novel role of NOD1 activation, via NF-κB/PKA lipolytic activation, in inducing lipolysis in adipocytes and suggest that NOD1 activation may contribute to dyslipidemia in obesity.

Effects of dietary stearidonic acid on biomarkers of lipid metabolism.

Stearidonic acid (SDA), a highly unsaturated (n-3) PUFA, is effectively metabolized to EPA with a bioequivalence of ~5:1 as determined by the omega-3 index, a biomarker for risk of cardiovascular disease. The AHA has recommended that individuals increase their consumption of highly unsaturated (n-3) PUFA, particularly EPA and DHA, but there are concerns about achieving the recommendations through fish consumption. SDA is considered a biological surrogate for EPA. SDA-enriched soybean oil whose SDA content is ~30% could be a novel mechanism to seamlessly incorporate highly unsaturated (n-3) PUFA into the food supply; however, the effects of SDA are poorly understood, particularly at the transcriptional level. This paper reviews the human literature of the effects of dietary SDA on circulating lipids as directly compared with EPA at bioequivalent doses. These results were then compared to the effects of SDA on expression patterns of hepatic lipolytic and lipogenic genes in swine fed diets containing SDA at levels similar with those doses used in human trials. Supplementing SDA at doses of 3.7-4.2 g/d, of which the bioequivalence to EPA is ≤1 g/d, had little impact on modifying circulating TG and total, LDL, and HDL cholesterol, recapitulating the results with EPA at doses of 1.0-1.5 g/d. These results were generally supported by the gene expression patterns in swine. Although many lipolytic and lipogenic genes remained unchanged, several lipogenic genes were downregulated and a number of other biomarkers considered atheroprotective, such as C-reactive protein and paraoxonase, were favorably modified.

Conclusions and recommendations from the symposium, Heart Healthy Omega-3s for Food: Stearidonic Acid (SDA) as a Sustainable Choice.

Faculty who had presented at the symposium "Heart Healthy Omega-3s (n-3 fatty acids) for Food: Stearidonic Acid (SDA) as a Sustainable Choice" met and agreed upon conclusions and recommendations that could be made on the basis of evidence provided at the symposium. The participants also submitted manuscripts relating to their topics and these are presented in this supplement. These manuscripts were reviewed and also contributed to the conclusions and recommendations presented herein. The three major objectives of the symposium were to: 1) increase understanding of the current and emerging knowledge regarding the health benefits of (n-3) fatty acids (FA) including a focus on stearidonic acid (SDA) and EPA; 2) evaluate the importance of increasing (n-3) FA consumption in the US and the current challenge of doing so via mainstream foods; and 3) consider the health and food application benefits of SDA as a precursor to EPA and a plant-based sustainable source of highly unsaturated (n-3) FA for mainstream foods. Specific areas for future research were defined and included in the summary and conclusions herein. Overall evidence-based conclusions included: the current evidence provides a strong rationale for increasing (n-3) FA intakes in the US and other populations; current consumption of (n-3) FA in most populations is either insufficient or not efficient at providing adequate tissue levels of the long-chain (n-3) FA EPA and DHA; SDA in soybean oil appears to be a cost-effective and sustainable plant-based source that could contribute to reaching recommended levels of (n-3) FA intake, but more research and surveillance is needed; and adding SDA-enriched soybean oil to foods should be considered as a natural fortification approach to improving (n-3) FA status in the US and other populations. References for these conclusions and recommendations can be found in the articles included in the supplement.

Zyflamend, a combination of herbal extracts, attenuates tumor growth in murine xenograft models of prostate cancer.

Prostate cancer (PrC) is the second deadliest cancer of males in the United States Hormone deprivation therapy (HDT), a common therapy for advanced forms of the disease, results in tumor regression; unfortunately, tumors inevitably become castrate-resistant. Diet is not an appropriate primary therapy for refractory forms of the disease; however, diet may be effective as an adjuvant to HDT, potentially extending the latency period and delaying relapse and/or inhibiting refractory growth. Zyflamend® is a combination of extracts from multiple herbs, each with reported anticancer properties. Zyflamend can inhibit growth of various PrC cell lines, but no studies have investigated its potential use in vivo using a model of castrate-resistant PrC. In this study, oral doses of Zyflamend at human equivalent doses inhibited androgen-dependent and castrate-resistant tumor growth in a mouse model that mimics advanced stages of the disease, and reduced the expression of a number of biomarkers linked to PrC progression including pAKT, prostate specific antigen, histone deacetylases, and androgen receptor. In summary, this is the first article to report that Zyflamend, when provided at human equivalent doses, can potentiate the effects of hormone deprivation on tumor regression and growth inhibition of androgen-dependent and castrate-resistant PrC tumors in vivo.

Stearidonic and eicosapentaenoic acids inhibit interleukin-6 expression in ob/ob mouse adipose stem cells via Toll-like receptor-2-mediated pathways.

Increased adipose tissue positively correlates with circulating inflammatory cytokines such as IL-6. We previously reported that adipose stem cells from genetically obese ob/ob mice produce significantly higher levels of IL-6 compared with other cell types such as adipocytes and macrophages within adipose tissue. We also demonstrated that (n-3) PUFA have antiinflammatory effects on adipocyte IL-6 secretion. Based on these findings, we hypothesized that EPA [20:5 (n-3)] and stearidonic acid [SDA, 18:4 (n-3)] would decrease LPS (200 µg/L)-induced IL-6 secretion and IL-6 mRNA content in the adipose stem cells. SDA (100 µmol/L) and EPA (100 µmol/L) significantly reduced LPS-induced IL-6 secretion and decreased IL-6 mRNA expression. To determine the underlying intracellular mechanisms, we tested whether LPS-induced Toll-like-receptor (TLR) 4 and TLR2 expression were modulated by these fatty acids using Western-blot analysis. EPA and SDA suppressed LPS-induced TLR2 but not TLR4 protein expression in the adipose stem cells. Furthermore, SDA and EPA significantly lowered the activation and translocation of NF-κB, a TLR2 downstream signaling target, while protein expression of extracellular signal-regulated kinases-1/2 were unaffected. Collectively, our results suggest that EPA and SDA inhibit LPS-induced IL-6 secretion and IL-6 mRNA expression in the adipose stem cells by decreasing TRL2-mediated signaling pathways.

Zyflamend reduces the expression of androgen receptor in a model of castrate-resistant prostate cancer.

Prostate cancer is the most commonly diagnosed solid malignancy, and tumor cells eventually transform to castrate resistance through multiple pathways including activation of the androgen receptor via insulin-like growth factor receptor (IGF-1R) signaling involving phospho-AKT (pAKT). In this study, a mixture of herbal extracts, Zyflamend®, was used as a treatment in a model of castrate-resistant prostate cancer using CWR22Rv1 cells. Zyflamend reduced androgen receptor and IGF-1R expression along with a reduction of IGF-1-mediated proliferation of CWR22Rv1 cells. IGF-1 induced downstream AKT phosphorylation; however, the induction of pAKT was not associated with androgen receptor expression. Further, constitutively active form of AKT had no effect on nuclear expression of androgen receptor, indicating that upregulation of pAKT did not promote androgen receptor expression or nuclear translocation in castrate-resistant CWR22Rv1 cells. Conversely, Zyflamend reduced androgen receptor expression following IGF-1 stimulation and in cells overexpressing pAKT. These results demonstrated that Zyflamend inhibited IGF-1-stimulated cell growth, IGF-1R expression, and androgen receptor expression and its nuclear localization, but these effects were not dependent upon phosphatidylinositol 3-kinase/pAKT signaling. In conclusion, Zyflamend decreased cell proliferation and inhibited IGF-1R and androgen receptor expression in a phosphatidylinositol 3-kinase/pAKT independent manner.

Conversion of dietary polyunsaturated fats between humans and rodents: A review of allometric scaling models.

The purpose of this research was to explore various allometric scaling models for dietary nutrients to improve translational validity between preclinical experimental rodent models and humans, focusing on polyunsaturated fats. Currently, there is no authoritative document that provides standardized guidelines for which dietary designs can be based on to improve translational fidelity between species. This paper reviews the challenges of using a rodent model, the major allometric scaling models, the use of these mathematical models to extrapolate human equivalent doses, and then tests one of these models using data generated in mice, with comparisons of data generated in human clinical trials. Mice were fed diets containing micro- and macronutrient compositions that approximated the US diet based on energy distribution and were then supplemented with increasing levels of various n-3 and n-6 polyunsaturated fatty acids at human equivalent doses. Changes in plasma and erythrocyte fatty acid phospholipid compositions were determined and compared to corresponding data generated in humans. Our findings suggest that basing lipid composition on percent of energy may result in comparable outcomes between mice and humans and that extrapolation of non-energy producing nutrients between species might be done using differences in energy needs (based on food intake).

Zyflamend, a unique herbal blend, induces cell death and inhibits adipogenesis through the coordinated regulation of PKA and JNK.

The prevalence of obesity and its comorbidities has sparked a worldwide concern to address rates of adipose tissue accrual. Recent studies have demonstrated a novel role of Zyflamend, a blend of natural herbal extracts, in regulating lipid metabolism in several cancer cell lines through the activation of the AMPK signalling pathway. Yet, the role of Zyflamend in adipogenic differentiation and lipid metabolism remains largely unexplored. The objective of this study is to investigate the effects of Zyflamend on white 3T3-MBX pre-adipocyte differentiation and elucidate the molecular mechanisms. We demonstrate that Zyflamend treatment altered cell cycle progression, attenuated proliferation, and increased cell death of 3T3-MBX pre-adipocytes. In addition, treatment with Zyflamend inhibited lipid accumulation during the differentiation of 3T3-MBX cells, consistent with decreased expression of lipogenic genes and increased lipolysis. Mechanistically, Zyflamend-induced alterations in adipogenesis were mediated, at least in part, through the activation of AMPK, PKA, and JNK. Inhibition of AMPK partially reversed Zyflamend-induced inhibition of differentiation, whereas the inhibition of either JNK or PKA fully restored adipocyte differentiation and decreased lipolysis. Taken together, the present study demonstrates that Zyflamend, as a novel anti-adipogenic bioactive mix, inhibits adipocyte differentiation through the activation of the PKA and JNK pathways. ABBREVIATION: 7-AAD: 7-amino-actinomycin D; ACC: acetyl-CoA carboxylase; AKT: protein kinase B; AMPK: AMP-activated protein kinase; ATGL: adipose triglyceride lipase; C/EBPα: CCAAT-enhancer binding protein alpha; DMEM: Dulbecco's Modified Eagle Medium; DMSO: dimethyl sulphoxide; DTT: dithiothreitol; EGTA: ethylene glycol-bis-(2-aminoethyl)-N,N,N',N'-tetraacetic acid; ERK: extracellular signal-regulated kinases; FASN: fatty acid synthase; FBS: foetal bovine serum; GLUT: glucose transporter; HSL: hormone-sensitive lipase; IR: insulin receptor; IRS: insulin receptor substrate; JNK: c-JUN N-terminal kinase; MGL: monoacylglycerol lipase; NaF: sodium fluoride; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; PBS: phosphate buffered- saline; PCB: pyruvate carboxylase; PDE: phosphodiesterase; PKA: protein kinase cAMP-dependent; PMSF: phenylmethylsulfonyl fluoride; PPARγ: perilipin peroxisome proliferator-activated receptor gamma; PREF-1: pre-adipocyte factor 1; PVDF: polyvinylidene fluoride; RIPA: radio-immunoprecipitation assay; SDS-PAGE: sodium dodecyl sulphate polyacrylamide gel electrophoresis; SEM: standard error of the mean; SOX9: suppressor of cytokine signalling 9; TGs: triacylglycerols.

Dietary n-3 polyunsaturated fatty acids enhance hormone ablation therapy in androgen-dependent prostate cancer.

Hormone ablation therapy typically causes regression of prostate cancer and represents an important means of treating this disease, particularly after metastasis. However, hormone therapy inevitably loses its effectiveness as tumors become androgen-independent, and this conversion often leads to death because of subsequent poor responses to other forms of treatment. Because environmental factors, such as diet, have been strongly linked to prostate cancer, we examined the affects of dietary polyunsaturated fatty acids (PUFAs; at 1.5 wt%) on growth of androgen-dependent (CWR22) and androgen-independent (CWR22R) human prostatic cancer xenografts, the acute response of CWR22 tumors to ablation therapy, and their progression to androgen independence. Significant diet-induced changes in tumor n-3 or n-6 PUFA content had no affect on CWR22 or CWR22R tumors growing with or without androgen support, respectively. However, dietary changes that increased tumor eicosapentaenoic acid and linoleic acid content enhanced responses to ablation therapy, measured by cancer cell apoptosis and mitosis. In addition, relapse to androgen-independent growth (measured by renewed increases in tumor volume and serum prostate-specific antigen after ablation) positively correlated with tumor arachidonic acid content. There was no correlation between expression of 15-lipoxygenase isozymes or their products and tumor growth or responses to ablation. In conclusion, dietary n-3 PUFA may enhance the response of prostate cancer to ablation therapy and retard progression to androgen-independent growth by altering tumor PUFA content.

Dietary stearidonic acid is a long chain (n-3) polyunsaturated fatty acid with potential health benefits.

The therapeutic and health-promoting effects of (n-3) long-chain PUFA (LCPUFA) from fish are well known, although these same benefits may not be shared by their precursor, alpha-linolenic acid (ALA). World-wide agencies and scientific organizations (i.e. FDA, AHA, International Society for the Study of Fatty Acids and Lipids, Institute of Medicine, WHO, etc.) have made similar dietary recommendations for (n-3) LCPUFA; however, due to concerns regarding the safety of consuming fish, alternative sources of (n-3) LCPUFA are being investigated. One such lipid is stearidonic acid (SDA), a naturally occurring (n-3) PUFA that may have similar biological properties to eicosapentaenoic acid (EPA), a major (n-3) PUFA in fish oil. Existing and novel plant sources rich in SDA are being cultivated and promoted as potential alternatives to marine-based (n-3) PUFA. This critical review provides a direct comparison of SDA with other dietary (n-3) PUFA under similar experimental conditions. The comparative results suggest that SDA shares many of the biological effects of (n-3) LCPUFA and functions most similarly to dietary EPA compared with ALA when consumed in a typical Western diet. Therefore, although SDA may not replace fish as a major dietary source of (n-3) LCPUFA, it could become a prominent surrogate for EPA in the commercial development of foods fortified with (n-3) PUFA.

Towards establishing dietary reference intakes for eicosapentaenoic and docosahexaenoic acids.

There is considerable interest in the impact of (n-3) long-chain PUFA in mitigating the morbidity and mortality caused by chronic diseases. In 2002, the Institute of Medicine concluded that insufficient data were available to define Dietary Reference Intakes (DRI) for eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), noting only that EPA and DHA could contribute up to 10% toward meeting the Adequate Intake for alpha-linolenic acid. Since then, substantial new evidence has emerged supporting the need to reassess this recommendation. Therefore, the Technical Committee on Dietary Lipids of the International Life Sciences Institute North America sponsored a workshop on 4-5 June 2008 to consider whether the body of evidence specific to the major chronic diseases in the United States--coronary heart disease (CHD), cancer, and cognitive decline--had evolved sufficiently to justify reconsideration of DRI for EPA+DHA. The workshop participants arrived at these conclusions: 1) consistent evidence from multiple research paradigms demonstrates a clear, inverse relation between EPA+DHA intake and risk of fatal (and possibly nonfatal) CHD, providing evidence that supports a nutritionally achievable DRI for EPA+DHA between 250 and 500 mg/d; 2) because of the demonstrated low conversion from dietary ALA, protective tissue levels of EPA+DHA can be achieved only through direct consumption of these fatty acids; 3) evidence of beneficial effects of EPA+DHA on cognitive decline are emerging but are not yet sufficient to support an intake level different from that needed to achieve CHD risk reduction; 4) EPA+DHA do not appear to reduce risk for cancer; and 5) there is no evidence that intakes of EPA+DHA in these recommended ranges are harmful.

Pyruvate kinase M2: A simple molecule with complex functions.

Pyruvate kinase M2 is a critical enzyme that regulates cell metabolism and growth under different physiological conditions. In its metabolic role, pyruvate kinase M2 catalyzes the last glycolytic step which converts phosphoenolpyruvate to pyruvate with the generation of ATP. Beyond this metabolic role in glycolysis, PKM2 regulates gene expression in the nucleus, phosphorylates several essential proteins that regulate major cell signaling pathways, and contribute to the redox homeostasis of cancer cells. The expression of PKM2 has been demonstrated to be significantly elevated in several types of cancer, and the overall inflammatory response. The unusual pattern of PKM2 expression inspired scientists to investigate the unrevealed functions of PKM2 and the therapeutic potential of targeting PKM2 in cancer and other disorders. Therefore, the purpose of this review is to discuss the mechanistic and therapeutic potential of targeting PKM2 with the focus on cancer metabolism, redox homeostasis, inflammation, and metabolic disorders. This review highlights and provides insight into the metabolic and non-metabolic functions of PKM2 and its relevant association with health and disease.

Dietary supplementation with Zyflamend poly-herbal extracts and fish oil inhibits intimal hyperplasia development following vascular intervention.

The polyherbal blend Zyflamend™ has been shown to have anti-inflammatory properties and attenuate inflammatory-modulated pathologies. Fish oils have also been shown to have cardioprotective properties. However, the beneficial effects of their combination have not been investigated. Intimal hyperplasia (IH), a pathological remodeling response of a vessel to injury, is heavily regulated by an immune-mediated reaction. The objective of this study was to determine if dietary supplementation with Zyflamend and/or Wholemega could affect inflammatory-dependent vascular remodeling mechanisms when provided at human equivalent doses. Based on their anti-inflammatory properties and protective benefits demonstrated in previous pre-clinical studies, we hypothesized administration of these supplements would prevent IH in an animal model of vascular injury. The diets of aged male rats were supplemented with human equivalent doses of Zyflamend (Zyf) and/or Wholemega (WMega) or placebo (Plac) for 1wk prior to balloon angioplasty (BA)-induced injury of the left carotid artery. At 28d post-injury morphometric analysis of carotid tissue revealed IH was decreased in Zyf + WMega animals compared to placebo, while Zyf or WMega independently had no significant effect. Serum cytokine screening indicated injury-induced interleukin family isoforms, interferon-γ, and macrophage inflammatory proteins were downregulated by Zyf + WMega. Immunohistochemical staining for monocyte/macrophage phenotypic markers revealed that while overall monocyte/macrophage vessel infiltration was not affected, Zyf + WMega limited the alternative differentiation of M2 macrophages and reduced the presence of myofibroblasts in the injured vessel wall. In summary, dietary supplementation with Zyf + WMega attenuated the acute inflammatory response following vascular injury and inhibited IH development in vivo.