Curcumin induces stress response, neurite outgrowth and prevent NF-kappaB activation by inhibiting the proteasome function.

Abstract: Cancer is a hyperproliferative disorder that is usually treated by chemotherapeutic agents that are toxic not only to tumor cells but also to normal cells, so these agents produce major side effects. In addition, these agents are highly expensive and thus not affordable for most. Moreover, such agents cannot be used for cancer prevention. Traditional medicines are generally free of the deleterious side effects and usually inexpensive. Curcumin, a component of turmeric (Curcuma longa), is one such agent that is safe, affordable, and efficacious. How curcumin kills tumor cells is the focus of this review. We show that curcumin modulates growth of tumor cells through regulation of multiple cell signaling pathways including cell proliferation pathway (cyclin D1, c-myc), cell survival pathway (Bcl-2, Bcl-xL, cFLIP, XIAP, c-IAP1), caspase activation pathway (caspase-8, 3, 9), tumor suppressor pathway (p53, p21) death receptor pathway (DR4, DR5), mitochondrial pathways, and protein kinase pathway (JNK, Akt, and AMPK). How curcumin selectively kills tumor cells, and not normal cells, is also described in detail.

Abstract: A lthough our knowledge of cancer biology has advanced a great deal, neither the incidence of cancer nor the rate of death due to cancer has changed in the last 50 years. Most drugs currently available for the treatment of cancer have limited potential because they are very toxic, highly inefficient in treating cancer, or highly expensive and thus beyond the reach of the majority. Treatments without these disadvantages are needed. Curcumin is one such agent; derived from turmeric (Curcumin longa), it has been used for thousands of years in the Orient as a healing agent for variety of illnesses. Research over the last few decades has shown that curcumin is a potent antiinflammatory agent with strong therapeutic potential against a variety of cancers. Curcumin has been shown to suppress transformation, proliferation, and metastasis of tumors. These effects are mediated through its regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. It also inhibits proliferation of cancer cells by arresting them in various phases of the cell cycle and by inducing apoptosis. Moreover, curcumin has the ability to inhibit carcinogen bioactivation via suppression of specific cytochrome P450 isozymes, and to induce the activity or expression of phase II carcinogen detoxifying enzymes, which may account for its cancer chemopreventive effects. Curcumin has been shown to have protective and therapeutic effects against cancers of the blood, skin, oral cavity, lung, pancreas, and intestinal tract, and to suppress angiogenesis and metastasis in rodents. The current review focuses on the molecular mechanisms by which curcumin mediates its effects against various cancers. Curcumin is the most active component of turmeric, a botanical agent derived from the dried rhizome of the turmeric plant (Curcuma longa), a perennial herb belonging to the ginger family that is cultivated extensively in south and southeast tropical Asia. The rhizome, or root, is processed into turmeric powder, which is 2% to 5% curcumin. Turmeric is widely consumed in 1 the Indian subcontinent, south Asia, and Japan. It has a variety of uses;

Abstract: Phenolic compounds constitute a group of secondary metabolites which have important functions in plants. Besides the beneficial effects on the plant host, phenolic metabolites (polyphenols) exhibit a series of biological properties that influence the human in a health-promoting manner. Evidence suggests that people can benefit from plant phenolics obtained either by the diet or through skin application, because they can alleviate symptoms and inhibit the development of various skin disorders. Due to their natural origin and low toxicity, phenolic compounds are a promising tool in eliminating the causes and effects of skin aging, skin diseases, and skin damage, including wounds and burns. Polyphenols also act protectively and help prevent or attenuate the progression of certain skin disorders, both embarrassing minor problems (e.g., wrinkles, acne) or serious, potentially life-threatening diseases such as cancer. This paper reviews the latest reports on the potential therapy of skin disorders through treatment with phenolic compounds, considering mostly a single specific compound or a combination of compounds in a plant extract.

Abstract: Despite significant advances in treatment modalities over the last decade, neither the incidence of the disease nor the mortality due to cancer has altered in the last thirty years. Available anti-cancer drugs exhibit limited efficacy, associated with severe side effects, and are also expensive. Thus identification of pharmacological agents that do not have these disadvantages is required. Curcumin, a polyphenolic compound derived from turmeric (Curcumin longa), is one such agent that has been extensively studied over the last three to four decades for its potential anti-inflammatory and/or anti-cancer effects. Curcumin has been found to suppress initiation, progression, and metastasis of a variety of tumors. These anti-cancer effects are predominantly mediated through its negative regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other oncogenic molecules. It also abrogates proliferation of cancer cells by arresting them at different phases of the cell cycle and/or by inducing their apoptosis. The current review focuses on the diverse molecular targets modulated by curcumin that contribute to its efficacy against various human cancers.

Abstract: Although traditional medicines have been used for thousands of years, for most such medicines neither the active component nor their molecular targets have been very well identified. Curcumin, a yellow component of turmeric or curry powder, however, is an exception. Although inhibitors of cyclooxygenase-2, HER2, tumor necrosis factor, EGFR, Bcr-abl, proteosome, and vascular endothelial cell growth factor have been approved for human use by the United States Food and Drug Administration (FDA), curcumin as a single agent can down-regulate all these targets. Curcumin can also activate apoptosis, down-regulate cell survival gene products, and up-regulate p53, p21, and p27. Although curcumin is poorly absorbed after ingestion, multiple studies have suggested that even low levels of physiologically achievable concentrations of curcumin may be sufficient for its chemopreventive and chemotherapeutic activity. Thus, curcumin regulates multiple targets (multitargeted therapy), which is needed for treatment of most diseases, and it is inexpensive and has been found to be safe in human clinical trials. The present article reviews the key molecular mechanisms of curcumin action and compares this to some of the single-targeted therapies currently available for human cancer.

Abstract: Between the 1960s and 1980s, most life scientists focused their attention on studies of nucleic acids and the translation of the coded information. Protein degradation was a neglected area, conside...

Abstract: Curcumin (diferuloylmethane) is a polyphenol derived from the plant Curcuma longa, commonly called turmeric. Extensive research over the last 50 years has indicated this polyphenol can both prevent and treat cancer. The anticancer potential of curcumin stems from its ability to suppress proliferation of a wide variety of tumor cells, down-regulate transcription factors NF- κB, AP-1 and Egr-1; down-regulate the expression of COX2, LOX, NOS, MMP-9, uPA, TNF, chemokines, cell surface adhesion molecules and cyclin D1; down-regulate growth factor receptors (such as EGFR and HER2); and inhibit the activity of c-Jun N-terminal kinase, protein tyrosine kinases and protein serine/threonine kinases. In several systems, curcumin has been described as a potent antioxidant and anti-inflammatory agent. Evidence has also been presented to suggest that curcumin can suppress tumor initiation, promotion and metastasis. Pharmacologically, curcumin has been found to be safe. Human clinical trials indicated no dose-limiting toxicity when administered at doses up to 10 g/day. All of these studies suggest that curcumin has enormous potential in the prevention and therapy of cancer. The current review describes in detail the data supporting these studies. Curcumin, derived from turmeric (vernacular name: Haldi), is a rhizome of the plant Curcuma longa. The medicinal use of this plant has been documented in Ayurveda (the Indian

Abstract: The data reviewed indicate that extracts of Curcuma longa exhibit anti-inflammatory activity after parenteral application in standard animal models used for testing anti-inflammatory activity It turned out that curcumin and the volatile oil are at least in part responsible for this action It appears that when given orally, curcumin is far less active than after ip administration This may be due to poor absorption, as discussed Data on histamine-induced ulcers are controversial, and studies on the secretory activity (HCl, pepsinogen) are still lacking In vitro, curcumin exhibited antispasmodic activity Since there was a protective effect of extracts of Curcuma longa on the liver and a stimulation of bile secretion in animals, Curcuma longa has been advocated for use in liver disorders Evidence for an effect on liver disease in humans is not yet available From the facts that after oral application only traces of curcumin were found in the blood and that, on the other hand, most of the curcumin is excreted via the faeces it may be concluded that curcumin is absorbed poorly by the gastrointestinal tract and/or underlies presystemic transformation Systemic effects therefore seem to be questionable after oral application except that they occur at very low concentrations of curcumin This does not exclude a local action in the gastrointestinal tract

Abstract: When activated, NF-κB, a ubiquitous transcription factor, binds DNA as a heterodimeric complex composed of members of the Rel/NF-κB family of polypeptides. Because of its intimate involvement in host defense against disease, this transcription factor is an important target for therapeutic intervention. In the present report we demonstrate that curcumin (diferuloylmethane), a known anti-inflammatory and anticarcinogenic agent, is a potent inhibitor of NF-κB activation. Treatment of human myeloid ML-1a cells with tumor necrosis factor (TNF) rapidly activated NF-κB, which consists of p50 and p65 subunits, and this activation was inhibited by curcumin. AP-1 binding factors were also found to be down-modulated by curcumin, whereas the Sp1 binding factor was unaffected. Besides TNF, curcumin also blocked phorbol ester- and hydrogen peroxide-mediated activation of NF-κB. The TNF-dependent phosphorylation and degradation of IκBα was not observed in curcumin-treated cells; the translocation of p65 subunit to the nucleus was inhibited at the same time. The mechanism of action of curcumin was found to be different from that of protein tyrosine phosphatase inhibitors. Our results indicate that curcumin inhibits NF-κB activation pathway at a step before IκBα phosphorylation but after the convergence of various stimuli.

Abstract: The proteasome inhibitor PS-341 inhibits IκB degradation, prevents NF-κB activation, and induces apoptosis in several types of cancer cells, including chemoresistant multiple myeloma (MM) cells. PS-341 has marked clinical activity even in the setting of relapsed refractory MM. However, PS-341-induced apoptotic cascade(s) are not yet fully defined. By using gene expression profiling, we characterized the molecular sequelae of PS-341 treatment in MM cells and further focused on molecular pathways responsible for the anticancer actions of this promising agent. The transcriptional profile of PS-341-treated cells involved down-regulation of growth/survival signaling pathways, and up-regulation of molecules implicated in proapoptotic cascades (which are both consistent with the proapoptotic effect of proteasome inhibition), as well as up-regulation of heat-shock proteins and ubiquitin/proteasome pathway members (which can correspond to stress responses against proteasome inhibition). Further studies on these pathways showed that PS-341 decreases the levels of several antiapoptotic proteins and triggers a dual apoptotic pathway of mitochondrial cytochrome c release and caspase-9 activation, as well as activation of Jun kinase and a Fas/caspase-8-dependent apoptotic pathway [which is inhibited by a dominant negative (decoy) Fas construct]. Stimulation with IGF-1, as well as overexpression of Bcl-2 or constitutively active Akt in MM cells also modestly attenuates PS-341-induced cell death, whereas inhibitors of the BH3 domain of Bcl-2 family members or the heat-shock protein 90 enhance tumor cell sensitivity to proteasome inhibition. These data provide both insight into the molecular mechanisms of antitumor activity of PS-341 and the rationale for future clinical trials of PS-341, in combination with conventional and novel therapies, to improve patient outcome in MM.