Garlic exosome-like nanoparticles reverse high-fat diet induced obesity via the gut/brain axis.

Background: Obesity is becoming a global epidemic and reversing the pathological processes underlying obesity and metabolic co-morbidities is challenging. Obesity induced chronic inflammation including brain inflammation is a hallmark of obesity via the gut-brain axis. The objective of this study was to develop garlic exosome-like nanoparticles (GaELNs) that inhibit systemic as well as brain inflammatory activity and reverse a HFD induced obesity in mice. Methods: GELNs were isolated and administrated orally into HFD fed mice. GaELNs were fluorescent labeled for monitoring their in vivo trafficking route after oral administration and quantified the number particles in several tissues. The brain inflammation was determined by measuring inflammatory cytokines by ELISA and real-time PCR. Mitochondrial membrane permeability of microglial cells was determined using JC-10 fluorescence dye. The in vivo apoptotic cell death was quantified by TUNEL assay. The brain metabolites were identified and quantified by LC-MS analysis. Memory function of the mice was determined by several memory functional analysis. The effect of GaELNs on glucose and insulin response of the mice was determined by glucose and insulin tolerance tests. c-Myc localization and interaction with BASP1 and calmodulin was determined by confocal microscopy. Results: Our results show that GaELNs is preferentially taken up microglial cells and inhibits the brain inflammation in HFD mice. GaELN phosphatidic acid (PA) (36:4) is required for the uptake of GaELNs via interaction with microglial BASP1. Formation of the GaELNs/BASP1 complex is required for inhibition of c-Myc mediated expression of STING. GaELN PA binds to BASP1, leading to inhibition of c-Myc expression and activity through competitively binding to CaM with c-Myc transcription factor. Inhibition of STING activity leads to reducing the expression of an array of inflammatory cytokines including IFN-γ and TNF-α. IFN-γ induces the expression of IDO1, which in turn the metabolites generated as IDO1 dependent manner activate the AHR pathway that contributes to developing obesity. The metabolites derived from the GaELNs treated microglial cells promote neuronal differentiation and inhibit mitochondrial mediated neuronal cell death. GaELNs treated HFD mice showed improved memory function and increased glucose tolerance and insulin sensitivity in these mice. Conclusion: Collectively, these results demonstrate how nanoparticles from a healthy diet can inhibit unhealthy high-fat diet induced brain inflammation and reveal a link between brain microglia/diet to brain inflammatory disease outcomes via diet-derived exosome-like nanoparticles.

A pilot study to evaluate the safety and efficacy of an oral dose of (-)-epigallocatechin-3-gallate-rich polyphenon E in patients with mild to moderate ulcerative colitis.

BACKGROUND: Green tea and its main polyphenolic component, (-)-epigallocatechin-3-gallate (EGCG), exert powerful anti-inflammatory effects that are protective against both inflammatory diseases and cancer. Research with animal and human cell lines provide plausible support for these claims. Poor absorption results in low systemic bioavailability of EGCG after oral administration but high colonic mucosal exposure. METHODS: Patients with mild to moderate ulcerative colitis (UC) were randomized to daily doses of oral Polyphenon E (400 mg or 800 mg of total EGCG daily, administered in split doses) or placebo in a double-blinded, placebo-controlled pilot study. Response was measured by the UC disease activity index and the inflammatory bowel disease questionnaire on day 56. RESULTS: Twenty patients were randomized to active therapy or placebo in a 4:1 ratio. Nineteen subjects received >1 dose of study medication (15 Polyphenon E, 4 placebo). The mean UC disease activity index score at study entry was 6.5 ± 1.9 in the treatment group and 7.3 ± 1.7 in the placebo group. After 56 days of therapy, the response rate was 66.7% (10 of 15) in the Polyphenon E group and 0% (0 of 4) in the placebo group (P = 0.03). The active treatment remission rate was 53.3% (8 of 15) compared with 0% (0 of 4) for placebo (P = 0.10). Polyphenon E treatment resulted in only minor side effects. CONCLUSIONS: Administration of Polyphenon E resulted in a therapeutic benefit for patients who were refractory to 5-aminosalicylic and/or azathioprine. This agent holds promise as a novel option for the treatment of patients with UC with mild to moderately active disease.

Overview of biologic therapy for Crohn's disease.

Therapy for Crohn's disease (CD) is evolving at breakneck speed. Biologic therapies are assuming ever more important roles in treating this unrelenting, life-long disorder. New evidence suggests that earlier, more aggressive use of biological therapies for CD may improve overall efficacy rates, as well as reduce long-term complications. In addition to optimizing the use of older biologic therapies (antibodies against TNF-alpha), recent and ongoing clinical trials are evaluating the clinical efficacy of a large number of other biologic therapies, honing in on a wide array of immunological targets. The promise of biologic therapies stems from their ability to induce complete and long-lasting remission of symptoms in a way that 'standard' therapies have not been able to accomplish. In this review of biologic therapies for CD, we examine the latest clinical trial data and evidence for mechanism of action of a variety of current and future therapies.

Polyphenols and gastrointestinal diseases.

PURPOSE OF REVIEW: This article will review the role of polyphenols in gastrointestinal diseases. Ingested polyphenols are concentrated in the gastrointestinal tract and are not well absorbed into the rest of the body. Thus, the high luminal concentrations achieved support a potential for therapeutic uses in the gastrointestinal tract. Additionally, there is great interest from the general public in complementary and alternative medicine. RECENT FINDINGS: Dietary polyphenols are a major source of antioxidants consumed by humans. Polyphenols possess not only antioxidant properties but also antiviral, antibacterial, antiinflammatory and anticarcinogenic effects, as well as the ability to modulate certain signaling pathways such as nuclear factor-kappaB activation. Green tea polyphenols have been shown to have efficacy in various models of inflammatory bowel disease. Silymarin, or milk thistle, is hepatoprotective against many forms of experimental liver injury and is widely used in human liver diseases, such as hepatitis C and alcoholic cirrhosis, with an excellent safety profile (but with unclear efficacy). SUMMARY: Substantial in-vitro and animal studies support the beneficial effects of polyphenols in many gastrointestinal diseases. Well designed multicenter trials in humans, such as those called for in the 2005 National Institutes of Health Requests for Applications for Silymarin Centers, will be critical for defining the safety, appropriate dosing and therapeutic efficacy of such agents.

Clinical implications of oxidative stress and antioxidant therapy.

Oxidative stress occurs when there is an imbalance between generation of reactive oxygen species and inadequate antioxidant defense systems. Oxidative stress can cause cell damage either directly or through altering signaling pathways. Oxidative stress is a unifying mechanism of injury in many types of disease processes, including gastrointestinal diseases. For example, in alcoholic liver disease, reactive oxygen species have been detected through direct spin-trapping techniques and through indirect markers, such as products of lipid peroxidation. A host of antioxidants have protected against liver injury in animal models of alcoholic liver disease. Similarly, in inflammatory bowel disease, oxidative stress has been postulated to play a role in disease initiation and progression, and antioxidant therapy, such as green tea polyphenols and gene therapy with superoxide dismutase, has a markedly attenuated disease. Downregulation of specific detoxification genes may play a role in the pathogenesis of inflammatory bowel disease, especially in ulcerative colitis. Oxidative stress is postulated to play a sustaining role in acute and chronic pancreatitis. Antioxidant supplementation has been used with some success in the treatment of chronic pancreatitis. This review covers recent findings related to oxidative stress in liver disease, inflammatory bowel disease, and pancreatitis.

Nutritional supplements and alternative medicine.

PURPOSE OF REVIEW: A major health care trend in the last decade has been the increased use of complementary and alternative medicine and nutritional supplements. Indeed, we now have Physician's Desk References for both herbal therapies and dietary supplements. A large amount of out-of-pocket dollars are spent on complementary and alternative medicine each year in the United States, and complementary and alternative medicine users believe strongly in the efficacy of their treatments. RECENT FINDINGS: In the area of inflammatory bowel disease, probiotics appear to be a highly promising form of therapy. In acute pancreatitis, enteral nutrition has been shown to be safe and effective. Peppermint oil is one of the most widely used complementary and alternative medicine therapies for irritable bowel syndrome. Antioxidants are increasingly used in liver disease, especially agents involved in methionine metabolism. Both S-adenosylmethionine and betaine have shown efficacy in animal models of alcoholic liver disease, and "knockout" mice that develop S-adenosylmethionine deficiency also develop steatohepatitis. Thus, there is great interest in these complementary and alternative medicine agents in both alcoholic liver disease and nonalcoholic steatohepatitis. There are also important safety issues related to complementary and alternative medicine. Deaths of well-known athletes have highlighted the risks of ephedra, and some research suggests that complementary and alternative medicine agents are a major cause of fulminant liver failure necessitating liver transplantation. SUMMARY: Thus, physicians must be aware not only of the potential therapeutic benefits of complementary and alternative medicine agents and nutritional supplements, but also their potential risks, including toxicity and drug interactions.