Biological effects of essential oils - A review

Curcumin, a polyphenolic compound derived from dietary spice turmeric, possesses diverse pharmacologic effects including anti-inflammatory, antioxidant, antiproliferative and antiangiogenic activities. Phase I clinical trials have shown that curcumin is safe even at high doses (12 g/day) in humans but exhibit poor bioavailability. Major reasons contributing to the low plasma and tissue levels of curcumin appear to be due to poor absorption, rapid metabolism, and rapid systemic elimination. To improve the bioavailability of curcumin, numerous approaches have been undertaken. These approaches involve, first, the use of adjuvant like piperine that interferes with glucuronidation; second, the use of liposomal curcumin; third, curcumin nanoparticles; fourth, the use of curcumin phospholipid complex; and fifth, the use of structural analogues of curcumin (e.g., EF-24). The latter has been reported to have a rapid absorption with a peak plasma half-life. Despite the lower bioavailability, therapeutic efficacy of...

Bioavailability of curcumin: problems and promises.

Infectious Diseases Society of America.

PLoS BIOLOGY Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor Jean-Philippe Coppe 1 , Christopher K. Patil 1[ , Francis Rodier 1,2[ , Yu Sun 3 , Denise P. Mun oz 1,2 , Joshua Goldstein 1¤ , Peter S. Nelson 3 , Pierre-Yves Desprez 1,4 , Judith Campisi 1,2* 1 Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America, 2 Buck Institute for Age Research, Novato, California, United States of America, 3 Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America, 4 California Pacific Medical Center Research Institute, San Francisco, California, United States of America Cellular senescence suppresses cancer by arresting cell proliferation, essentially permanently, in response to oncogenic stimuli, including genotoxic stress. We modified the use of antibody arrays to provide a quantitative assessment of factors secreted by senescent cells. We show that human cells induced to senesce by genotoxic stress secrete myriad factors associated with inflammation and malignancy. This senescence-associated secretory phenotype (SASP) developed slowly over several days and only after DNA damage of sufficient magnitude to induce senescence. Remarkably similar SASPs developed in normal fibroblasts, normal epithelial cells, and epithelial tumor cells after genotoxic stress in culture, and in epithelial tumor cells in vivo after treatment of prostate cancer patients with DNA- damaging chemotherapy. In cultured premalignant epithelial cells, SASPs induced an epithelial–mesenchyme transition and invasiveness, hallmarks of malignancy, by a paracrine mechanism that depended largely on the SASP factors interleukin (IL)-6 and IL-8. Strikingly, two manipulations markedly amplified, and accelerated development of, the SASPs: oncogenic RAS expression, which causes genotoxic stress and senescence in normal cells, and functional loss of the p53 tumor suppressor protein. Both loss of p53 and gain of oncogenic RAS also exacerbated the promalignant paracrine activities of the SASPs. Our findings define a central feature of genotoxic stress-induced senescence. Moreover, they suggest a cell-nonautonomous mechanism by which p53 can restrain, and oncogenic RAS can promote, the development of age-related cancer by altering the tissue microenvironment. Citation: Coppe JP, Patil CK, Rodier F, Sun Y, Mun oz DP, et al. (2008) Senescence-associated secretory phenotypes reveal cell-nonautonomous functions of oncogenic RAS and the p53 tumor suppressor. PLoS Biol 6(12): e301. doi:10.1371/journal.pbio.0060301 Introduction Cancer is a multistep disease in which cells acquire increasingly malignant phenotypes. These phenotypes are acquired in part by somatic mutations, which derange normal controls over cell proliferation (growth), survival, invasion, and other processes important for malignant tumorigenesis [1]. In addition, there is increasing evidence that the tissue microenvironment is an important determinant of whether and how malignancies develop [2,3]. Normal tissue environ- ments tend to suppress malignant phenotypes, whereas abnormal tissue environments such at those caused by inﬂammation can promote cancer progression. Cancer development is restrained by a variety of tumor suppressor genes. Some of these genes permanently arrest the growth of cells at risk for neoplastic transformation, a process termed cellular senescence [4–6]. Two tumor suppressor pathways, controlled by the p53 and p16INK4a/pRB proteins, regulate senescence responses. Both pathways integrate multiple aspects of cellular physiology and direct cell fate towards survival, death, proliferation, or growth arrest, depending on the context [7,8]. Several lines of evidence indicate that cellular senescence is a potent tumor-suppressive mechanism [4,9,10]. Many poten- tially oncogenic stimuli (e.g., dysfunctional telomeres, DNA PLoS Biology | www.plosbiology.org damage, and certain oncogenes) induce senescence [6,11]. Moreover, mutations that dampen the p53 or p16INK4a/pRB pathways confer resistance to senescence and greatly increase cancer risk [12,13]. Most cancers harbor mutations in one or both of these pathways [14,15]. Lastly, in mice and humans, a senescence response to strong mitogenic signals, such as those delivered by certain oncogenes, prevents premalignant lesions from progressing to malignant cancers [16–19]. Academic Editor: Julian Downward, Cancer Research UK, United Kingdom Received June 27, 2008; Accepted October 22, 2008; Published December 2, 2008 Copyright: O 2008 Coppe et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abbreviations: CM, conditioned medium; DDR, DNA damage response; ELISA, enzyme-linked immunosorbent assay; EMT, epithelial–mesenchymal transition; GSE, genetic suppressor element; IL, interleukin; MIT, mitoxantrone; PRE, presenescent; PrEC, normal human prostate epithelial cell; REP, replicative exhaustion; SASP, senescence-associated secretory phenotype; SEN, senescent; shRNA, short hairpin RNA; XRA, X-irradiation * To whom correspondence should be addressed. E-mail: jcampisi@lbl.gov [ These authors contributed equally to this work. ¤ Current address: Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America December 2008 | Volume 6 | Issue 12 | e301

Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor

Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review

Dietary polyphenols represent a wide variety of compounds that occur in fruits, vegetables, wine, tea, extra virgin olive oil, chocolate and other cocoa products. They are mostly derivatives and/or isomers of flavones, isoflavones, flavonols, catechins and phenolic acids, and possess diverse biological properties such as antioxidant, antiapoptosis, anti-aging, anticarcinogen, anti-inflammation, anti-atherosclerosis, cardiovascular protection, improvement of the endothelial function, as well as inhibition of angiogenesis and cell proliferation activity. Most of these biological actions have been attributed to their intrinsic reducing capabilities. They may also offer indirect protection by activating endogenous defense systems and by modulating cellular signaling processes such as nuclear factor-kappa B (NF-κB) activation, activator protein-1(AP-1) DNA binding, glutathione biosynthesis, phosphoinositide 3 (PI3)-kinase/protein kinase B (Akt) pathway, mitogen-activated protein kinase (MAPK) proteins [extracellular signal-regulated protein kinase (ERK), c-jun N-terminal kinase (JNK) and P38 ] activation, and the translocation into the nucleus of nuclear factor erythroid 2 related factor 2 (Nrf2). This paper covers the most recent literature on the subject, and describes the biological mechanisms of action and protective effects of dietary polyphenols.

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Dietary Polyphenols and Their Biological Significance

Validated LC/MS/MS assay for curcumin and tetrahydrocurcumin in rat plasma and application to pharmacokinetic study of phospholipid complex of curcumin.

The genus Commiphora: a review of its traditional uses, phytochemistry and pharmacology

Grape seed extract (GSE) has been reported to exert protective effects on various forms of cardiac disorders. The cardiovascular protective effects of GSE are believed to be ascribed to its antioxidative properties. A series of studies have demonstrated that polyphenols are instrumental for the antioxidative properties of GSE. This study was undertaken to investigate whether two major polyphenols isolated from GSE (catechin and proanthocyanidin B4) could increase the endogenous antioxidant enzymes in cardiomyocytes, and whether such increased cellular defenses could provide protection against oxidative cardiac cell injury. Incubation of cardiac H9C2 cells with micromolar concentrations of catechin or proanthocyanidin B4 resulted in a significant induction of cellular antioxidant enzymes in a concentration-dependent fashion. Furthermore, catechine or proanthocyanidin B4 pretreatment led to a marked reduction in xanthine oxidase (XO)/xanthine-induced intracellular reactive oxygen species (ROS) accumulation and cardiac cell apoptosis. These results indicated that grape seed polyphenols (GSP) could protect against cardiac cell apoptosis via the induction of endogenous antioxidant enzymes. This may be an important mechanism underlying the protective effects of GSE observed with various forms of cardiovascular disorders.

Hong-Xiang Lou

Papers

Dietary Polyphenols and Their Biological Significance

Validated LC/MS/MS assay for curcumin and tetrahydrocurcumin in rat plasma and application to pharmacokinetic study of phospholipid complex of curcumin.

The genus Commiphora: a review of its traditional uses, phytochemistry and pharmacology

Grape seed polyphenols protect cardiac cells from apoptosis via induction of endogenous antioxidant enzymes

A-type proanthocyanidins from peanut skins