Dietary flaxseed lignan or oil combined with tamoxifen treatment affects MCF‐7 tumor growth through estrogen receptor‐ and growth factor‐signaling pathways

This study aimed to elucidate which component of flaxseed, i.e. secoisolariciresinol diglucoside (SDG) lignan or flaxseed oil (FO), makes tamoxifen (TAM) more effective in reducing growth of established estrogen receptor positive breast tumors (MCF‐7) at low circulating estrogen levels, and potential mechanisms of action. In a 2×2 factorial design, ovariectomized athymic mice with established tumors were treated for 8 wk with TAM together with basal diet (control), or basal diet supplemented with SDG (1 g/kg diet), FO (38.5 g/kg diet), or combined SDG and FO. SDG and FO were at levels in 10% flaxseed diet. Palpable tumors were monitored and after animal sacrifice, analyzed for cell proliferation, apoptosis, ER‐mediated (ER‐α, ER‐β, trefoil factor 1, cyclin D1, progesterone receptor, AIBI), growth factor‐mediated (epidermal growth factor receptor, human epidermal growth factor receptor‐2, insulin‐like growth factor receptor‐1, phosphorylated mitogen activated protein kinase, PAKT, BCL2) signaling pathways and angiogenesis (vascular endothelial growth factor). All treatments reduced the growth of TAM‐treated tumors by reducing cell proliferation, expression of genes, and proteins involved in the ER‐ and growth factor‐mediated signaling pathways with FO having the greatest effect in increasing apoptosis compared with TAM treatment alone. SDG and FO reduced the growth of TAM‐treated tumors but FO was more effective. The mechanisms involve both the ER‐ and growth factor‐signaling pathways.     

Lactobacillus plantarum AR501 Alleviates the Oxidative Stress of D‐Galactose‐Induced Aging Mice Liver by Upregulation of Nrf2‐Mediated Antioxidant Enzyme Expression

Lactic acid bacteria (LAB) have been used as ingredients of functional foods to promote health and prevent diseases because of their beneficial effects. This study aimed to investigate the antioxidative effects of LAB on the hepatotoxicity in D‐galactose‐induced aging mice. LAB were isolated from the traditional Chinese fermented foods and screened by the tolerance of hydrogen peroxide (H₂O₂). Male ICR (Institute of Cancer Research) mice were subcutaneously injected with D‐galactose for 5 weeks and then gastric gavage with LAB for 6 weeks. The results showed that Lactobacillus plantarum AR113 and AR501, and Pediococcu pentosaceus AR243 could tolerate up to 1.5 mM H₂O₂ in vitro, and they could live through simulated gastrointestinal tract (GIT) to colonizing the GIT of host. In vivo, oral administration of L. plantarum AR113 and AR501 improved the antioxidant status of D‐galactose‐induced oxidative stress mice such as alleviated liver damages and reduced abnormal activities of superoxide dismutase, glutathione peroxidase, and catalase to normal levels. In addition, L. plantarum AR501 markedly elevated the gene expression of nuclear factor erythroid‐2‐related factor 2 and upregulated the expressions of several antioxidant genes such as glutathione reductase, glutathione S‐transferase, glutamate‐cysteine ligase catalytic subunit, glutamate‐cysteine ligase modifier subunit, and NAD(P)H quinone oxidoreductase 1 in the liver of an aging mice. Therefore, L. plantarum AR501 could be a good candidate for producing antiaging functional foods.     

Role of TNF‐α polymorphism ‐308 in neurosensory irritation

Neurosensory cutaneous discomfort in response to topical products is common, yet the relationship between symptoms such as stinging and visible irritation is currently unclear. The presence of a polymorphism at position ‐308 on the TNF‐α gene has been associated with skin irritation, i.e., erythema, dryness. Individuals with a G to A transition (AA/GA genotypes) have a lower threshold to experimentally induced irritation than those with the wild type (G allele, GG genotype). We investigated the effect of this polymorphism on neurosensory irritation (NSI). DNA genotyping was used to determine the allele type amongst a population of health care workers. The neurosensory response to lactic acid and water on the nasolabial folds and hands was assessed using a quantitative lactic acid sting test. Both genotypes had a more intense response to lactic acid compared with water on the face. The AA/GA genotypes had directionally higher scores from lactic acid (P = 0.1) and significantly higher stinging intensities from water (P = 0.001) on the face. For the hands, stinging intensities were higher for lactic acid and water amongst the AA/GA genotypes (P = 0.03 and 0.006 respectively). NSI to lactic acid was significantly higher on the face than on the hands (P < 0.05). Our findings indicate that subjects with the A transition at position ‐308 on the TNF‐α gene experience more intense NSI with common ingredients, i.e., lactic acid and water, than those with the wild type. TNF‐α polymorphism ‐308 may account for some of the inter‐individual variability in response to skin care practices.     

Myricetin attenuates lipopolysaccharide‐stimulated activation of mouse bone marrow‐derived dendritic cells through suppression of IKK/NF‐κB and MAPK signalling pathways

BACKGROUND: Myricetin is a naturally occurring flavonoid that is found in many fruits, vegetables, teas and medicinal herbs. It has been demonstrated to have anti‐inflammatory properties, but, to date, no studies have described the immunomodulatory effects of myricetin on the functions of dendritic cells (DCs). The aim of this study was to evaluate the potential for myricetin to modulate lipopolysaccharide (LPS)‐stimulated activation of mouse bone marrow‐derived DCs. RESULTS: Our experimental data showed that treatment with myricetin up to 10 µg mL⁻¹ does not cause cytotoxicity in cells. Myricetin significantly decreased the secretion of tumour necrosis factor‐α, interleukin‐6 and interleukin‐12p70 by LPS‐stimulated DCs. The expression of LPS‐induced major histocompatibility class II, CD40 and CD86 on DCs was also inhibited by myricetin, and the endocytic and migratory capacity of LPS‐stimulated DCs was blocked by myricentin. In addition, LPS‐stimulated DC‐elicited allogeneic T‐cell proliferation was reduced by myricetin. Moreover, our results confirmed that myricetin attenuates the responses of LPS‐stimulated activation of DCs via suppression of IκB kinase/nuclear factor‐κB and mitogen‐activated protein kinase‐dependent pathways. CONCLUSION: Myricetin has novel immunopharmacological activity, and modulation of DCs by myricetin may be an attractive strategy for the treatment of inflammatory and autoimmune disorders, and for transplantation. Copyright © 2012 Society of Chemical Industry     

The Quality Changes of Postharvest Mulberry Fruit Treated by Chitosan‐g‐Caffeic Acid during Cold Storage

This study aimed to characterize the effects of chitosan‐g‐caffeic acid (CTS‐g‐CA) on improving the quality and extending the shelf life of postharvest mulberry fruit during storage at 4 °C for 18 d. CTS‐g‐CA was enzymatically synthesized using laccase from Pleurotus ostreatus as a catalyst. The synergistic effects of CTS‐g‐CA treatment on mulberry fruit were evaluated using a co‐toxicity factor (cf). The results showed that the rotting rate of CTS‐g‐CA‐treated fruit was 37.67% (compared with that of the control at 97.67%) on day 18. The weight loss and malondialdehyde (MDA) contents of the CTS‐g‐CA‐treated mulberry fruit were significantly lower (P < 0.05) than those of the control, CA, CTS, and CA+CTS treatments. Moreover, the DPPH and ABTS radical scavenging activities of the CTS‐g‐CA treatment were both higher than those of the control. Furthermore, the CTS‐g‐CA treatment also maintained higher levels of main active substances, such as anthocyanins, ascorbic acid, polyphenols and flavones, in mulberry fruit than the other treatments. Therefore, CTS‐g‐CA could be used to improve the quality and extend the shelf life of postharvest mulberry fruit during cold storage.