Metabolites Of Curcuminoids Research Articles

The influence of food matrices on the bioavailability of curcuminoids from a dried colloidal turmeric suspension: a randomized, crossover, clinical trial.

Curcuminoid absorption can be influenced by the presence of additional compounds, but there has been no study investigating this in a robust manner. The aim of this clinical trial was to assess the effect of the type of food matrix on the absorption of curcuminoids from a highly bioavailable turmeric formulation. Participants consumed the turmeric formulation in the form of capsules, a ready-to-drink fruit nectar, a sports nutrition bar, a dairy analogue (oat milk), pectin gummies, and a probiotic drink in a randomized, crossover study. Plasma samples were collected over a 24-hour period to assess the pharmacokinetics of curcuminoids. The relative bioavailability of total curcuminoids was increased in all the food matrices compared to that in the capsule formulation. The dairy analogue showed the highest increase in dose-normalized AUC24 h (+76%, p < 0.0001) and Cmax (+105%, p < 0.0001). The sports nutrition bar resulted in increased dose-normalized AUC24 h (+40%, p = 0.0112) and Cmax (+74%, p < 0.0001). The probiotic drink showed increased dose-normalized AUC24 h (+35%, p = 0.0318) and Cmax (+52%, p < 0.0001). The ready-to-drink and gummy formulations were bioequivalent to the capsules. The distribution of curcuminoid metabolites was similar in all the matrices. In conclusion, there was no negative food matrix effect; on the contrary, the bioavailability of curcuminoids can be improved when administered via food matrices, particularly those containing lipids in a suspended form or polar lipids.

Ru(II)-Arene Complexes of Curcumin and Bisdesmethoxycurcumin Metabolites.

Curcuminoids and their complexes continue to attract attention in medicinal chemistry, but little attention has been given to their metabolic derivatives. Here, the first examples of (arene)Ru(II) complexes with curcuminoid metabolites, tetrahydrocurcumin (THcurcH), and tetrahydrobisdesmethoxycurcumin (THbdcurcH) were prepared and characterized. The neutral complexes [Ru(arene)(THcurc)Cl] and [Ru(arene)(THbdcurc)Cl] (arene = cymene, benzene, or hexamethylbenzene) were characterized by NMR spectroscopy and ESI mass spectrometry, and the crystal structures of the three complexes were determined by X-ray diffraction analysis. Compared to curcuminoids, these metabolites lose their conjugated double bond system responsible for their planarity, showing unique closed conformation structures. Both closed and open conformations have been analyzed and rationalized by using density functional theory (DFT). The cytotoxicity of the complexes was evaluated in vitro against human ovarian carcinoma cells (A2780 and A2780cisR), human breast adenocarcinoma cells (MCF-7 and MCF-7CR), as well as against non-tumorigenic human embryonic kidney cells (HEK293) and human breast (MCF-10A) cells and compared to the free ligands, cisplatin, and RAPTA-C. There is a correlation between cellular uptake and the cytotoxicity of the compounds, suggesting that cellular uptake and binding to nuclear DNA may be the major pathway for cytotoxicity. However, the levels of complex binding to DNA do not strictly correlate with the cytotoxic potency, indicating that other mechanisms are also involved. In addition, treatment of MCF-7 cells with [Ru(cym)(THcurc)Cl] showed a significant decrease in p62 protein levels, which is generally assumed as a noncisplatin-like mechanism of action involving autophagy. Hence, a cisplatin- and a noncisplatin-like concerted mechanism of action, involving both apoptosis and autophagy, is possible.

Acute supplementation with a curcuminoid-based formulation fails to enhance resting or exercise-induced NRF2 activity in males and females.

Purpose: Exercise and (poly)phenols may activate nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor that coordinates antioxidant synthesis. The purpose of this study was to determine whether curcuminoid supplementation augments resting and exercise-induced NRF2 activity. Methods: In a double-blinded, randomised, between-subjects design, 14 males and 12 females performed plyometric exercise (100 drop jumps, 50 squat jumps) following 4 d supplementation with a curcuminoid-based formulation (CUR + EX; n = 13; ∼200 mg d-1 curcuminoids) or a placebo (PLA + EX; n = 13). NRF2/DNA binding in peripheral blood mononuclear cells, plasma glutathione peroxidase (GPX), and plasma cytokines (interleukin-6 [IL-6], tumour necrosis factor-alpha [TNF-α]) were measured pre-, post-, 1, 2 h post-exercise. Curcuminoid metabolites were measured 0, 1, 2 h post-administration of a single bolus. Results: Total area under the curve for total curcuminoid metabolites was greater in CUR + EX (p < 0.01), with bioavailability peaking at 2 h post administration (CUR + EX: [0 h] 80.9 ± 117 nM [1 h] 76.6 ± 178.5 nM [2 h] 301.1 ± 584.7 nM; PLA + EX: [0 h] 10.4 ± 1.6 [1 h] 8.5 ± 2.6 [2 h] 10.6 ± 2.1). NRF2 activity did not increase in PLA + EX (p = 0.78) or CUR + EX (p = 0.76); however, curcuminoid metabolite concentrations did positively predict NRF2/DNA binding (R2 = 0.39; p = 0.02). Exercise increased IL-6 (p = 0.03) but TNF-α was unresponsive (p = 0.97) and lower across PLA + EX (p = 0.03). GPX activity was higher in CUR + EX (p < 0.01) but not in PLA + EX (p = 0.94). Conclusion: Supplementation with a curcuminoid-based formulation failed to augment resting or exercise-induced NRF2/DNA binding; however, higher concentrations of curcuminoid metabolites predicted NRF2/DNA binding response, suggesting effects may be dependent on bioavailability.

Functional characterization of key polyketide synthases by integrated metabolome and transcriptome analysis on curcuminoid biosynthesis in Curcuma wenyujin

Leaf and tuber extracts of Curcuma wenyujin contain a mixture of curcuminoids. However, the curcuminoid constituents and their molecular mechanisms are poorly understood, and the relevant curcumin synthases remain unclear. In this study, we comprehensively compared the metabolite profiles of the leaf and tuber tissues of C. wenyujin. A total of 11 curcuminoid metabolites were identified and exhibited differentially changed contents in the leaf and tuber tissues. An integrated analysis of metabolomic and transcriptomic data revealed the proposed biosynthesis pathway of curcuminoid. Two candidate type Ⅲ polyketide synthases (PKSs) were identified in the metabolically engineering yeasts, indicating that CwPKS1 and CwPKS2 maintained substrate and product specificities. Especially, CwPKS1 is the first type Ⅲ PKS identified to synthesize hydrogenated derivatives of curcuminoid, dihydrocurcumin and tetrehydrocurcumin. Interestingly, the substitution of the glycine at position 219 with aspartic acid (G219D mutant) resulted in the complete inactivation of CwPKS1. Our results provide the first comparative metabolome analysis of C. wenyujin and functionally identified type Ⅲ PKSs, giving valuable information for curcuminoids biosynthesis.

Pharmacokinetics-Driven Evaluation of the Antioxidant Activity of Curcuminoids and Their Major Reduced Metabolites-A Medicinal Chemistry Approach.

Curcuminoids are the main bioactive components of the well-known Asian spice and traditional medicine turmeric. Curcuminoids have poor chemical stability and bioavailability; in vivo they are rapidly metabolized to a set of bioreduced derivatives and/or glucuronide and sulfate conjugates. The reduced curcuminoid metabolites were also reported to exert various bioactivities in vitro and in vivo. In this work, we aimed to perform a comparative evaluation of curcuminoids and their hydrogenated metabolites from a medicinal chemistry point of view, by determining a set of key pharmacokinetic parameters and evaluating antioxidant potential in relation to such properties.Reduced metabolites were prepared from curcumin and demethoxycurcumin through continuous-flow hydrogenation. As selected pharmacokinetic parameters, kinetic solubility, chemical stability, metabolic stability in human liver microsomes, and parallel artificial membrane permeability assay (PAMPA)-based gastrointestinal and blood-brain barrier permeability were determined. Experimentally determined logP for hydrocurcumins in octanol-water and toluene-water systems provided valuable data on the tendency for intramolecular hydrogen bonding by these compounds. Drug likeness of the compounds were further evaluated by a in silico calculations. Antioxidant properties in diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays were comparatively evaluated through the determination of ligand lipophilic efficiency (LLE). Our results showed dramatically increased water solubility and chemical stability for the reduced metabolites as compared to their corresponding parent compound. Hexahydrocurcumin was found the best candidate for drug development based on a complex pharmacokinetical comparison and high LLE values for its antioxidant properties. Development of tetrahydrocurcumin and tetrahydro-demethoxycurcumin would be limited by their very poor metabolic stability, therefore such an effort would rely on formulations bypassing first-pass metabolism.

Curcumin Metabolite Tetrahydrocurcumin in the Treatment of Eye Diseases

Curcumin is one of the most valuable natural products due to its pharmacological activities. However, the low bioavailability of curcumin has long been a problem for its medicinal use. Large studies have been conducted to improve the use of curcumin; among these studies, curcumin metabolites have become a relatively new research focus over the past few years. Additionally, accumulating evidence suggests that curcumin or curcuminoid metabolites have similar or better biological activity than the precursor of curcumin. Recent studies focus on the protective role of plasma tetrahydrocurcumin (THC), a main metabolite of curcumin, against tumors and chronic inflammatory diseases. Nevertheless, studies of THC in eye diseases have not yet been conducted. Since ophthalmic conditions play a crucial role in worldwide public health, the prevention and treatment of ophthalmic diseases are of great concern. Therefore, the present study investigated the antioxidative, anti-inflammatory, antiangiogenic, and neuroprotective effects of THC on four major ocular diseases: age-related cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). While this study aimed to show curcumin as a promising potential solution for eye conditions and discusses the involved mechanistic pathways, further work is required for the clinical application of curcumin.

The Effect of Formulation of Curcuminoids on Their Metabolism by Human Colonic Microbiota.

Turmeric (Curcuma longa L.) is the only edible plant recognized as a dietary source of curcuminoids, among which curcumin, demethoxycurcumin (DMC) and bis-demethoxycurcumin (Bis-DMC) are the most representative ones. Curcumin shows a very low systemic bioavailability and for this reason, several technologies have been adopted to improve it. These technologies generally improve curcuminoid absorption in the small intestine, however, no data are available about the effect of curcuminoid formulation on colonic biotransformation. The present study aims at investigating the human colonic metabolism of curcuminoids, prepared with two different technologies, using an in vitro model. Unformulated curcuminoid and lecithin-curcuminoid botanical extracts were fermented using an in vitro fecal model and colonic catabolites were identified and quantified by uHPLC-MSn. Native compounds, mainly curcumin, DMC and bis-DMC, were metabolized by colonic microbiota within the 24-h incubation. The degradation of curcuminoids led to the formation of specific curcuminoid metabolites, among which higher concentrations of bis(demethyl)-tetrahydrocurcumin and bis(demethyl)-hexahydrocurcumin were found after lecithin-extract fermentation compared to the concentration detected after unformulated extract. In conclusion, both curcumin-based botanical extracts can be considered important sources of curcuminoids, although the lecithin-formulated extract led to a higher production of curcuminoid catabolites. Moreover, a new curcuminoid catabolite, namely bis(demethyl)-hexahydrocurcumin, has been putatively identified, opening new perspectives in the investigation of curcuminoid bioavailability and their potential metabolite bioactivity.

Efficacy and Safety of Tetrahydrocurcuminoids for the Treatment of Canker Sore and Gingivitis.

Background Tetrahydrocurcuminoids (THCs) are among the major metabolites of curcuminoids with a higher bioavailability and physiological stability and exhibit a broad spectrum of therapeutic activities. The objective of this study was to evaluate the efficacy of THCs in patients suffering from canker sore and gingivitis designed as an exploratory clinical trial. Methods This is an open label prospective pilot clinical trial carried out at two clinical centers: Noble Hospital, Pune, Maharashtra, and Sri Venkateshwara Hospital, Bangalore, Karnataka in India. Participants were assigned to 21 days of treatment with chewable oral THCs supplement. Patients were instructed to self-administer one chewable tablet containing 100 mg of THCs twice daily for up to 21 days. This clinical trial was registered at a public Clinical Trial Registry in India (http://www.ctri.nic.in). Thirty-one canker sore and twenty-nine gingivitis patients participated in this study. Body mass index, throat numbness/relief, Visual Analog Scale (VAS) pain score, canker sore lesions, gingival appearance, inflammation and bleeding were assessed before and after treatment, at 14 and 21 days. Vital signs and laboratory parameters were assessed for safety. Results THCs treatment significantly reduced the reddening at the site, difficulty in chewing, swallowing, and VAS pain score in the canker sore patients. Further, both single and multiple lesions were completely healed. In gingivitis patients, gingival appearance, bleeding, and inflammation were significantly reduced. No adverse effects were observed during the study. Conclusion Overall, the findings of this study show that supplementation of THCs for 21 days reduced the pain and prevented the progression of the disease in patients suffering from canker sore and gingivitis without adverse side effects.

Bioactivity of Turmeric-derived Curcuminoids and Related Metabolites in Breast Cancer

While the chemotherapeutic effect of curcumin, one of three major curcuminoids derived from turmeric, has been reported, largely unexplored are the effects of complex turmeric extracts more analogous to traditional medicinal preparations, as well as the relative importance of the three curcuminoids and their metabolites as anti-cancer agents. These studies document the pharmacodynamic effects of chemically-complex turmeric extracts relative to curcuminoids on human breast cancer cell growth and tumor cell secretion of parathyroid hormone-related protein (PTHrP), an important driver of cancer bone metastasis. Finally, relative effects of structurallyrelated metabolites of curcuminoids were assessed on the same endpoints. We report that 3 curcuminoid-containing turmeric extracts differing with respect to the inclusion of additional naturally occurring chemicals (essential oils and/or polar compounds) were equipotent in inhibiting human breast cancer MDA-MB-231 cell growth (IC50=10-16µg/mL) and secretion of osteolytic PTHrP (IC50=2-3µg/mL) when concentrations were normalized to curcuminoid content. Moreover, these effects were curcuminoid-specific, as botanically-related gingerol containing extracts had no effect. While curcumin and bis-demethoxycurcumin were equipotent to each other and to the naturally occurring curcuminoid mixture (IC50=58µM), demethoxycurcumin did not have any effect on cell growth. However, each of the individual curcuminoids inhibited PTHrP secretion (IC50=22-31µM) to the same degree as the curcuminoid mixture (IC50=16µM). Degradative curcuminoid metabolites (vanillin and ferulic acid) did not inhibit cell growth or PTHrP, while reduced metabolites (tetrahydrocurcuminoids) had inhibitory effects on cell growth and PTHrP secretion but only at concentrations ≥10-fold higher than the curcuminoids. These studies emphasize the structural and biological importance of curcuminoids in the anti-breast cancer effects of turmeric and contradict recent assertions that certain of the curcuminoid metabolites studied here mediate these anti-cancer effects.

Curcuminoid Metabolism and its Contribution to the Pharmacological Effects

Curcuminoids are safe natural yellow pigments used as food coloring agents and traditional drugs with a variety of biological functions such as antitumor, anti-inflammatory and antioxidant activities. Poor oral bioavailability and the low plasma concentration of curcuminoids limited their clinical use, and one of the major reasons is their rapid metabolism in vivo. The predominant metabolic pathways are reduction and conjugation, and some drug metabolizing enzymes such as alcohol dehydrogenase, UDP-glucuronosyltransferases (UGTs) or sulfotransferases (SULTs) involved in the metabolic reactions. Besides the major metabolic pathways, dehydroxylation, cyclization and methylation can also occur in vivo. In addition, more than thirty metabolites of curcuminoids have been identified in biological matrices including the plasma, urine and bile from rats or humans by LC-MS/MS analysis and other methods. Some metabolites such as tetrahydro-curcuminoids have been reported to be active, which may explain how and why curcuminoids with poor oral bioavailability display their effectiveness in vivo. The present review mainly summarizes curcuminoid metabolism and its contribution to the pharmacological effects.

The effect of cyclodextrin-solubilized curcuminoids on amyloid plaques in Alzheimer transgenic mice: brain uptake and metabolism after intravenous and subcutaneous injection

IntroductionCurcuminoids may improve pathological conditions associated with Alzheimer's disease. However, their therapeutic potential is limited by their exceedingly low bioavailability after oral administration. A method to deliver solubilized curcuminoids by injection was evaluated in Alzheimer transgenic mice.MethodsAmyloid protein precursor (APP)SWE, PS1dE9 mice were intravenously or subcutaneously injected at weekly intervals between the ages of 4 and 12 months with serum- or cyclodextrin-solubilized curcuminoids to assess their potential for plaque prevention. Alternatively, mice between the ages of 11 and 12 months were intravenously injected with cyclodextrin-solubilized curcuminoids at biweekly intervals to evaluate their ability to eliminate existing plaques. Plasma and brain levels of curcuminoids and their metabolites were also determined after subcutaneous and intravenous injection.ResultsWeekly long-term injections did not result in a significant plaque load reduction. However, intravenous injection of cyclodextrin-solubilized curcuminoids at higher curcuminoid concentrations and at a biweekly frequency between the ages of 11 and 12 months reduced the plaque load to approximately 70% of the control value. After intravenous injection, plasma levels of 100 μM curcuminoids and brain levels of 47 nmol/g could initially be achieved that declined to essentially undetectable levels within 20 minutes. The primary curcuminoid metabolites in plasma were the conjugates of glucuronide or sulfate and hexahydrocurcuminoids as reduction products. In the brain, both hexahydrocurcuminoids and octahydrocurcuminoids were detected as major metabolites. After subcutaneous injection, maximal curcuminoid plasma levels of 23 μM and brain levels of 8 nmol/g were observed at 30 minutes after injection and curcuminoids remained detectable for 2 to 3 h.ConclusionCurcuminoids are rapidly metabolized after injection and their effect on reducing plaque load associated with Alzheimer's disease may be dependent on the frequency of administration.

Isolation and Identification of Phase 1 Metabolites of Curcuminoids in Rats

Curcuminoids are natural food coloring additives with anti-inflammatory, antioxidant, and anticarcinogenic activity, which contain mainly three diarylheptanoids: curcumin, demethoxycurcumin, and bisdemethoxycurcumin. In this paper, the metabolites of curcuminoids in the feces and urine of rats after oral administration by gavage were investigated. Four new metabolites, 3-hydroxy-[1-(4-hydroxyphenyl)-7-(3-hydroxyphey)] heptane-A (M1), 3-hydroxy-[1-(4-hydroxyphenyl)-7-(3-hydroxyphey)] heptane-B (M2), 3-hydroxy-1,7-bis(3-hydroxyphenyl) heptane-A (M3) and 3-hydroxy-1,7-bis(3-hydroxyphenyl) heptane-B (M4), along with five known metabolites (M5-M9), were isolated from the feces of male Wistar-derived rats and nine known metabolites (M5-M8, M10-M14) were isolated from the urine. Their structures were elucidated by extensive spectroscopic analysis. The finding that the metabolites occurred as several pairs of enantiomers was confirmed by chiral column chromatography. Based on the metabolites' profiles, possible metabolic pathways of the curcuminoids in rats are proposed.

Curcumin Bioavailability from Enriched Bread: The Effect of Microencapsulated Ingredients

Human bioavailability of curcumin from breads enriched with 1 g/portion of free curcumin (FCB), encapsulated curcumin (ECB), or encapsulated curcumin plus other polyphenols (ECBB) was evaluated. Parental and metabolized curcuminoids and phenolic acids were quantified by HPLC/MS/MS in blood, urine, and feces collected over 24 h. The concentrations of serum curcuminoids were always below 4 nmol/L and those of glucuronides 10-fold less. Encapsulation delayed and increased curcuminoid absorption as compared to the free ingredient. Serum and urinary concentrations of ferulic and vanillic acid were between 2- and 1000-fold higher than those of curcuminoids, with ECBB eliciting the highest amounts. Fecal curcuminoids were 6-fold more abundant after ECB than FCB, while phenolic acids after ECBB quadruplicated those after ECB. Curcuminoid encapsulation increased their bioavailability from enriched bread, probably preventing their biotransformation, with combined compounds slightly reducing this effect. Phenolic acids are the major metabolites of curcuminoids and may contribute to their biological properties.

HPLC Analysis of Curcuminoids in Dietary Supplements and in vitro Digestion Fractions

Curcumin (Cur), demethoxycurcumin (DMC), and bis‐demethoxycurcumin (BDMC) are the main curcuminoids in Curcuma longa used to prepare the spice turmeric. Cur has been shown to reduce the risk of cancer, inflammation and Alzheimers. As such, it has become increasingly popular in foods and dietary supplements. To examine content and bioaccessibility of commercial Cur products, we developed and validated an HPLC method to measure Cur and metabolites. Dietary supplements were processed via an in vitro digestion (simulated gastric and small intestinal phases) and Caco‐2 cellular uptake (Chitchumroonchokchai et al., J. Nutr. 2004). Cur, DMC, BDMC were monitored at 425nm for sensitive detection and 280nm was monitored to detect the internal standard, Flavone, and cellular metabolites of curcuminoids. Three products were tested containing from 10% to 95% curcuminoids. The micellarized Cur was stable in cell culture medium for at least 4 hrs. Transfer of Cur from the supplements to micelles during the small intestinal phase of digestion varied markedly between the two products. Micellarization was more efficient as polarity increased, i.e., BDMC&gt; DMC&gt;Cur. Efficiency (%) of incorporation into micelles was higher for Curcu‐Gel™ than Turm’Brite 10% sd Cur, 29.1% vs 8.7%. Cur in synthetic micelles was taken up by the cells in a time and concentration dependent manner. (Supported in part by Tishcon Corp., Westbury, NY)

Pharmacokinetics of curcuminoids contained in the phytopreparation arthroflex

Curcuminoids are the main active components in the extract of curcuma roots (Curcuma longa), which is widely used as an anti-inflammatory agent. We have studied the bioavailability and determined the pharmacokinetic parameters of curcuminoids contained in the complex phytopreparation Arthroflex studied experimentally in vitro and in vivo. The release of curcuminoids from Arthroflex into a nonconventional biphase system modeling conditions in the gastrointestinal tract was investigated in vitro and the dissolution rate constants were calculated. The pharmacokinetics of curcuminoids was investigated in vivo. It was established that curcumin in the initial form was missing from the blood plasma, and only two metabolites of curcuminoids were found by thin layer chromatography. The pharmacokinetic parameters of the major metabolite were determined.

Curcuminoids Form Reactive Glucuronides In Vitro

Curcumin is of current interest because of its putative anti-inflammatory, anticarcinogenic, and anti-Alzheimer's activity, but its pharmacokinetic and metabolic fate is poorly understood. The present in vitro study has therefore been conducted on the glucuronidation of curcumin and its major phase I metabolite, hexahydro-curcumin, as well as of various natural and artificial analogs. The predominant glucuronide generated by rat and human liver microsomes from curcumin, hexahydro-curcumin, and other analogs with a phenolic hydroxyl group was a phenolic glucuronide according to LC-MS/MS analysis. However, a second glucuronide carrying the glucuronic acid moiety at the alcoholic hydroxyl group was formed from the same curcuminoids, but not hexahydro-curcuminoids, by human microsomes. Curcuminoids without a phenolic hydroxyl group gave rise to the aliphatic glucuronide only. The phenolic glucuronides of curcuminoids, but not of hexahydro-curcuminoids, were rather lipophilic and, in part, unstable in aqueous solution, their stability depending strongly on the type of aromatic substitution. The phenolic glucuronide of curcumin and of its natural congeners, but not the parent compounds, clearly inhibited the assembly of microtubule proteins under cell-free conditions, implying chemical reactivity of the glucuronides. These novel properties of the major phase II metabolites of curcuminoids deserve further investigation.

Detection and quantitation of curcumin in mouse lung cell cultures by matrix-assisted laser desorption ionization time of flight mass spectrometry

A method to detect and quantify curcumin and two curcuminoid metabolites in biological matrices, including mouse serum and mouse lung cell cultures, was developed. Standard curves between 0.04 and 10.00 nmol curcumin were prepared in serum, giving correlation coefficients of 0.94–0.99. Alcoholic extraction, concentration, and addition of dilute hydrochloric acid to stabilize the curcumin were essential to the reproducibility of the protocol. Untreated and curcumin-treated mouse lung fibrotic and nonfibrotic cell cultures were analyzed by matrix-assisted laser desorption ionization time of flight mass spectrometry utilizing this method. Curcumin uptake was calculated to be 7.0–11.6% for the saline-treated cells and 7.4–11.9% for the bleomycin-treated cultures. Curcumin was not detected in untreated cells. Two additional peaks ( m/ z = 399 and 429) were observed in the curcumin-treated cells. These may be curcumin-derived products resulting from HCl treatment of the tissue samples.