Simon Yeung

Memorial Sloan-Kettering Cancer Center, New York City, New York, United States

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Publications (8)30.47 Total impact

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    ABSTRACT: The rhizome of Curcuma longa (turmeric) is often used in Asia as a spice and as a medicine. Its most well-studied component, curcumin, has been shown to exhibit poor bioavailability in animal studies and clinical trials. We hypothesized that the presence of lipophilic components (e.g., turmerones) in turmeric extract would affect the absorption of curcumin. The effects of turmerones on curcumin transport were evaluated in human intestinal epithelial Caco-2 cells. The roles of turmerones on P-glycoprotein (P-gp) activities and mRNA expression were also evaluated. Results showed that in the presence of α- and aromatic turmerones, the amount of curcumin transported into the Caco-2 cells in 2 hours was significantly increased. α-Turmerone and verapamil (a P-gp inhibitor) significantly inhibited the efflux of rhodamine-123 and digoxin (i.e., inhibited the activity of P-gp). It is interesting that aromatic turmerone significantly increased the rhodamine-123 efflux and P-gp (MDR1 gene) mRNA expression levels. The effects of α- and aromatic turmerones on curcumin transport as well as P-gp activities were shown here for the first time. The presence of turmerones did affect the absorption of curcumin in vitro. These findings suggest the potential use of turmeric extract (including curcumin and turmerones), rather than curcumin alone, for treating diseases.
    Journal of medicinal food 12/2011; 15(3):242-52. · 1.39 Impact Factor
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    ABSTRACT: Several curcuminoids and sesquiterpenoids isolated from Curcuma longa (CL) have been shown to have many pharmacological activities. In the present study, the immunomodulatory activities of the polar fractions of CL hot water extracts were investigated using human peripheral blood mononuclear cells (PBMC). Our results showed that the high polarity fraction of the hot water extract exhibited stimulatory effects on PBMC proliferation as shown in [methyl-(3)H]-thymidine incorporation assay. In an attempt to isolate the active components responsible for the activities, further partition with ethyl acetate, n-butanol and ethanol, progressively were performed. The cytokine productions (TGF-beta, TNF-alpha, GM-CSF, IL-1alpha, IL-5, IL-6, IL-8, IL-10, IL-13, etc.) have been modulated by a polysaccharide-enriched fraction as shown in ELISA and cytokine protein array. The proportion of CD14 positive stained PBMC was increased by such fraction. The composition of monosaccharide of the active fraction has been determined by GC-MS and gel permeation chromatography. The immunostimulatory effects of C. longa polysaccharides on PBMC were shown for the first time. The findings revealed the potential use of C. longa crude extract (containing curcuminoids and polysaccharides) as an adjuvant supplement for cancer patients, whose immune activities were suppressed during chemotherapies.
    International journal of biological macromolecules 10/2010; 47(3):342-7. · 2.37 Impact Factor
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    ABSTRACT: There are important safety concerns associated with dietary supplements and foods rich in phytoestrogens, especially for breast cancer patients with hormone-sensitive disease. However, no consensus has been reached concerning specific dietary items that should be avoided, and safe levels of potentially problematic foods have yet to be determined. Excellent qualitative reviews of phytoestrogens and breast cancer have been published. These list agents that contain phytoestrogens and offer general cautions. Quantitative reviews, however, are needed but not yet available. Here we review quantitative data on phytoestrogens, their interaction with estrogen receptors, their bioavailability and pharmacokinetics, and their effects on breast cancer cells and animal models. We also note foods and botanicals with substances that interact with estrogen receptors and discuss the phytoestrogens they contain. Based on current evidence, we propose recommendations for advising breast cancer patients, which may also serve as a basis for the development of clinical practice guidelines.
    Journal of the Society for Integrative Oncology 01/2010; 8(1):20-30.
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    ABSTRACT: Cancer patients commonly use dietary supplements to "boost immune function". A polysaccharide extract from Grifola frondosa (Maitake extract) showed immunomodulatory effects in preclinical studies and therefore the potential for clinical use. Whether oral administration in human produces measurable immunologic effects, however, is unknown. In a phase I/II dose escalation trial, 34 postmenopausal breast cancer patients, free of disease after initial treatment, were enrolled sequentially in five cohorts. Maitake liquid extract was taken orally at 0.1, 0.5, 1.5, 3, or 5 mg/kg twice daily for 3 weeks. Peripheral blood was collected at days -7, 0 (prior to the first dosing), 7, 14, and 21 for ex vivo analyses. The primary endpoints were safety and tolerability. No dose-limiting toxicity was encountered. Two patients withdrew prior to completion of the study due to grade I possibly related side effects: nausea and joint swelling in one patient; rash and pruritus in the second. There was a statistically significant association between Maitake and immunologic function (p < 0.0005). Increasing doses of Maitake increased some immunologic parameters and depressed others; the dose-response curves for many endpoints were non-monotonic with intermediate doses having either immune enhancing or immune suppressant effects compared with both high and low doses. Oral administration of a polysaccharide extract from Maitake mushroom is associated with both immunologically stimulatory and inhibitory measurable effects in peripheral blood. Cancer patients should be made aware of the fact that botanical agents produce more complex effects than assumed, and may depress as well as enhance immune function.
    Journal of Cancer Research and Clinical Oncology 03/2009; 135(9):1215-21. · 2.91 Impact Factor
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    ABSTRACT: We sought to determine whether an acupuncture technique specially developed for a surgical oncology population (intervention) reduces pain or analgesic use after thoracotomy compared with a sham acupuncture technique (control). One hundred sixty-two patients with cancer undergoing thoracotomy were randomized to group A (preoperative implantation of small intradermal needles that were retained for 4 weeks) or group B (preoperative placement of sham needles at the same schedule). The numeric rating scale of pain and total opioid use was evaluated during the in-patient stay, and the Brief Pain Inventory and Medication Quantification Scale were evaluated after discharge up to 3 months after the operation. The principal analysis, a comparison of Brief Pain Inventory pain intensity scores at the 30-day follow-up, showed no significant difference between the intervention and control groups. Pain scores were marginally higher in the intervention group (0.05; 95% confidence interval, 0.74 to -0.64; P = .9). There were also no statistically significant differences between groups for secondary end points, including chronic pain assessments at 60 and 90 days, in-patient pain, and medication use in the hospital and after discharge. A special acupuncture technique, as provided in this study, did not reduce pain or use of pain medication after thoracotomy more than a sham technique.
    The Journal of thoracic and cardiovascular surgery 01/2009; 136(6):1464-9. · 3.41 Impact Factor
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    ABSTRACT: Turmeric has been extensively utilized in Indian and Chinese medicine for its immune-modulatory properties. Dendritic cells (DCs) are antigen-presenting cells specialized to initiate and regulate immunity. The ability of DCs to initiate immunity is linked to their activation status. The effects of turmeric on human DCs have not been studied. Here we show that hydroethanolic (HEE) but not lipophilic "supercritical" extraction (SCE) of turmeric inhibits the activation of human DCs in response to inflammatory cytokines. Treatment of DCs with HEE also inhibits the ability of DCs to stimulate the mixed lymphocyte reaction (MLR). Importantly, the lipophilic fraction does not synergize with the hydroethanolic fraction for the ability of inhibiting DC maturation. Rather, culturing of DCs with the combination of HEE and SCE leads to partial abrogation of the effects of HEE on the MLR initiated by DCs. These data provide a mechanism for the anti-inflammatory properties of turmeric. However, they suggest that these extracts are not synergistic and may contain components with mutually antagonistic effects on human DCs. Harnessing the immune effects of turmeric may benefit from specifically targeting the active fractions.
    Planta Medica 12/2008; 75(4):312-5. · 2.35 Impact Factor
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    ABSTRACT: To determine the immediate and long-term effects of true acupuncture versus sham acupuncture on hot flash frequency in women with breast cancer. Seventy-two women with breast cancer experiencing three or more hot flashes per day were randomly assigned to receive either true or sham acupuncture. Interventions were given twice weekly for 4 consecutive weeks. Hot flash frequency was evaluated at baseline, at 6 weeks, and at 6 months after initiation of treatment. Patients initially randomly assigned to the sham group were crossed over to true acupuncture starting at week 7. The mean number of hot flashes per day was reduced from 8.7 (standard deviation [SD], 3.9) to 6.2 (SD, 4.2) in the true acupuncture group and from 10.0 (SD, 6.1) to 7.6 (SD, 5.7) in the sham group. True acupuncture was associated with 0.8 fewer hot flashes per day than sham at 6 weeks, but the difference did not reach statistical significance (95% CI, -0.7 to 2.4; P = .3). When participants in the sham acupuncture group were crossed over to true acupuncture, a further reduction in the frequency of hot flashes was seen. This reduction in hot flash frequency persisted for up to 6 months after the completion of treatment. Hot flash frequency in breast cancer patients was reduced following acupuncture. However, when compared with sham acupuncture, the reduction by the acupuncture regimen as provided in the current study did not reach statistical significance. We cannot exclude the possibility that a longer and more intense acupuncture intervention could produce a larger reduction of these symptoms.
    Journal of Clinical Oncology 01/2008; 25(35):5584-90. · 18.04 Impact Factor
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    ABSTRACT: Herbal supplements are being used by an increasing number of cancer patients for symptom relief both during and after treatment. But botanicals contain biologically active compounds that can interfere with chemotherapeutic drugs and other medications. Research is underway to determine the mechanism of action and beneficial effects of botanicals.
    12/2007: pages 161-180;