Interaction between vitamin E intake and a COMT gene variant on colorectal cancer risk among Korean adults: a case-control study.

OBJECTIVES: Previous human trials have not supported the anticarcinogenic effect of vitamin E despite biological plausibility and considerable epidemiological evidence. A possible explanation for this inconsistency is the interactive effect of the catechol-O-methyltransferase (COMT) gene and supplemental vitamin E on cancer. We examined whether a COMT gene variant modulates the effect of dietary vitamin E intake on colorectal cancer (CRC) risk. METHODS: In this case-control study of Korean adults (975 cases and 975 age- and sex-matched controls), dietary vitamin E density (mg/1,000 kcal) was measured using a semiquantitative food frequency questionnaire, COMT single nucleotide polymorphism (SNP) rs740603 (A>G) was genotyped, and CRC was verified histologically. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models with adjustments for potential confounders. RESULTS: Higher vitamin E density was associated with a lower risk of CRC (highest vs. lowest quartiles: OR, 0.72; 95% CI, 0.55 to 0.96; p-for-trend=0.002). When stratified by COMT SNP rs740603 genotype, the inverse association between vitamin E density and CRC risk was confined to those with at least 1 A allele (≥median vs.

Effect of kava (Piper methysticum) on peripheral gene expression among individuals with generalized anxiety disorder: A post hoc analysis of a randomized controlled trial.

Kava is a South Pacific plant-based medicine with anxiolytic properties, but little is known about the impact kava has on gene expression or whether gene expression can serve as a marker of kava response. This study aimed to determine whether kava treatment alters the expression of genes with physiological relevance to anxiety pathophysiology and whether the baseline expression of these physiologically relevant genes modifies the efficacy of kava treatment. In this post hoc analysis, we examined the expression of 48 genes relevant to the pathophysiology of anxiety collected from a double-blind randomized controlled trial that assessed the efficacy of kava treatment in generalized anxiety disorder. Peripheral blood gene expression was measured in 71 (34 kava, 37 placebo) adults at baseline and in 40 (19 kava, 21 placebo) after 8 weeks of treatment by reverse transcription polymerase chain reaction (PCR). Results revealed that kava decreased the expression of a subunit of the GABAA -rho receptor gene (GABRR2) and catechol-O-methyltransferase (COMT), a gene related to catecholamine metabolism. Kava efficacy was not found to be modified by baseline (pretreatment) expression of relevant genes. Although these results did not withstand statistical correction for multiple comparisons and require external validation, they support the notion that kava's mechanism of action includes interaction with GABAergic and catecholaminergic systems.

COMT Val158Met Affects the Analgesic Response to Acupuncture Among Cancer Survivors With Chronic Pain.

Catechol-O-methyltransferase (COMT) is the major enzyme involved in the catabolism of dopamine, a neurotransmitter in the brain's reward system. The common COMT polymorphism Val158Met (rs4680 G>A) modulates pain response to opioids through a reward-motivated mechanism; however, its role in nonpharmacological pain medicine has not been clinically characterized. We genotyped 325 participants from a randomized controlled trial of cancer survivors with chronic musculoskeletal pain. We found that carrying methionine at position 158 (158Met) of COMT, encoded by the A allele, significantly increased the analgesic response to electroacupuncture (74% vs 50%; odds ratio [OR]: 2.79; 95% confidence interval [CI]: 1.31, 6.05; P < .01), but not to auricular acupuncture (68% vs 60%; OR: 1.43; 95% CI: .65, 3.12; P = .37) or usual care (24% vs 18%; OR: 1.46; 95% CI: .38, 7.24; P = .61) compared to Val/Val. These findings raise the possibility that COMT Val158Met might be an important predictor of analgesic response to electroacupuncture, providing novel insights into precision nonpharmacologic pain management tailored to individual genetic backgrounds. PERSPECTIVE: This work suggests the modulating effects of the polymorphism in COMT Val158Met on the response to acupuncture. Further research needs to validate these findings, increase the mechanistic understanding of acupuncture, and guide further development of acupuncture as a precision pain management strategy.

Green tea extract supplementation does not modify plasma concentration of F2-isoprostanes in women who are postmenopause: Findings from a randomized controlled trial.

Green tea extract (GTE) is a potential mitigator of oxidative stress, and F2-isoprostanes are a reliable biomarker of oxidative stress. Genetic polymorphisms in the catechol-o-methyltransferase (COMT) gene may modify tea catechin metabolism, prolonging exposure. We hypothesized that GTE supplementation would decrease plasma F2-isoprostanes concentrations compared with placebo and that participants with the COMT genotype polymorphisms would experience a more significant expression of this outcome. This study was a secondary analysis of the Minnesota Green Tea Trial, a randomized placebo-controlled, double-blinded trial investigating the effects of GTE in women who were generally healthy and postmenopausal. The treatment group consumed 843 mg of epigallocatechin gallate daily for 12 months versus placebo. Participants in this study had a mean age of 60 years, were predominantly White, and most had a healthy body mass index. GTE supplementation did not significantly change plasma F2-isoprostanes concentrations compared with placebo after 12 months (P for overall treatment = .07). There were no significant interactions between treatment and age, or body mass index, physical activity, smoking history, and alcohol intake. COMT genotype did not modify the effect of GTE supplementation on F2-isoprostanes concentrations in the treatment group (P = .85). Among participants in the Minnesota Green Tea Trial, consuming GTE supplements daily for 1 year did not result in a significant decrease in plasma F2-isoprostanes concentrations. Likewise, the COMT genotype did not modify the effect of GTE supplementation on F2-isoprostanes concentrations.

Point-of-Care Testing of Enzyme Polymorphisms for Predicting Hypnotizability and Postoperative Pain.

Hypnotizability is a stable trait that moderates the benefit of hypnosis for treating pain, but limited availability of hypnotizability testing deters widespread use of hypnosis. Inexpensive genotyping of four single-nucleotide polymorphisms in the catechol-o-methyltransferase (COMT) gene was performed using giant magnetoresistive biosensors to determine if hypnotizable individuals can be identified for targeted hypnosis referrals. For individuals with the proposed optimal COMT diplotypes, 89.5% score highly on the Hypnotic Induction Profile (odds ratio, 6.12; 95% CI, 1.26-28.75), which identified 40.5% of the treatable population. Mean hypnotizability scores of the optimal group were significantly higher than the total population (P = 0.015; effect size = 0.60), an effect that was present in women (P = 0.0015; effect size = 0.83), but not in men (P = 0.28). In an exploratory cohort, optimal individuals also reported significantly higher postoperative pain scores (P = 0.00030; effect size = 1.93), indicating a greater need for treatment.

Hepatotoxicity with High-Dose Green Tea Extract: Effect of Catechol-O-Methyltransferase and Uridine 5'-Diphospho-glucuronosyltransferase 1A4 Genotypes.

The predominant catechin in green tea, epigallocatechin gallate (EGCG), may be hepatotoxic in high doses. Our objective was to investigate the influence of catechol-O-methyltransferase (COMT) and uridine 5'-diphospho-glucuronosyltransferase 1A4 (UGT1A4) genotypes on changes in liver injury biomarkers in response to long-term, high-dose green tea extract (GTE) supplementation among postmenopausal women. A secondary analysis was conducted using data from the Minnesota Green Tea Trial (N = 1,075), in which participants were randomized to consume high-dose GTE (843 mg/day EGCG) or placebo capsules for 12 months. Analysis of covariance adjusting for potential confounders was performed to examine changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST: ALT ratio, and alkaline phosphatase from baseline to months 3, 6, 9, and 12 across COMT and UGT1A4 genotypes. Mean age and BMI within the GTE group (n = 400) were 59.8 yrs and 25.1 kg/m2, respectively, and 98% of subjects were white. From baseline to month 3, mean AST: ALT ratio change was +1.0% in the COMT (rs4680) A/G genotype versus -4.8% in the A/A genotype (p = 0.03). From baseline to months 6 and 9, respectively, mean ALT change was +78.1% and +82.1% in the UGT1A4 (rs6755571) A/C genotype versus +28.0% and +30.1% in the C/C genotype (p < 0.001 and p = 0.004, respectively). The UGT1A4 (rs6755571) A/C genotype may be an important risk factor for clinically-relevant serum transaminase elevations with 6-9 months of high-dose GTE supplementation among postmenopausal women. Understanding the genetic underpinnings of GTE-related hepatotoxicity may allow for a genetically-informed paradigm for therapeutic use of GTE.

Chemical Profiles of Korean Bee Pollens and Their Catechol-O-methyltransferase Inhibitory Activities.

Bee pollen is an apicultural product collected by honeybees from flower stamens and is consumed to help maintain a healthy diet. In this study, the chemical profiles of 11 Korean bee pollens were investigated using molecular networking analysis. This analysis elucidated the presence of two major clusters, hydroxycinnamoyl acid amides (HCAAs, molecular network 1 (MN1)) and flavonoid glycosides (MN2), in the bee pollen samples. The inhibitory properties of the bee pollens and the isolated HCAAs toward human catechol-O-methyltransferase (COMT), a key neurotransmitter involved in Parkinson's disease and depression, were determined. N1,N5,N10-(E)-tricaffeoylspermidine ((E,E,E)-1) exhibited the highest activity of the four compounds isolated, with an IC50 value 16 µM, and inhibited COMT competitively. Quantitative analysis of HCAAs showed that the amounts of N1,N10-dicaffeoyl-N5-p-coumaroylspermidine (2) and N10-caffeoyl-N1,N5-di-p-coumaroylspermidine (3) contributed to the observed differences in the COMT inhibitory activities of Korean bee pollens. This study may lead to the prevention and treatment of Parkinson's disease and depression using bee pollens.

Prospective randomized trial evaluating blood and prostate tissue concentrations of green tea polyphenols and quercetin in men with prostate cancer.

We evaluated if chronic consumption of quercetin (Q) with green tea extract (GTE) enhances the bioavailability of GT polyphenols (GTPs) and reduces methylation activity as previously observed in mouse xenograft tumors. In this prospective, randomized, parallel design, placebo controlled study, thirty-one men with prostate cancer consumed daily 1 gram of GTE (830 mg of GTP) with 800 mg of Q (GT + Q) or placebo (GT + PL) for four weeks before prostatectomy. First morning voided urine was collected at baseline, 3 weeks and the day of surgery, and prostate tissue on the day of surgery. In week 3, plasma concentration of GTPs and Q was measured in blood collected before and 2 hours after the morning dose. Prostate tissue epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) were detected in 67 and 93% of participants in the GT + Q group and 75 and 94% of participants in the GT + PL group. Q was increased 14-fold, 12-fold and 4.5-fold in plasma, urine, and prostate tissue, respectively, in the GT + Q compared to the GT + PL-group. There was a trend for decreased EGC levels in urine collected prior to prostatectomy in the GT + Q compared to GT + PL-group (p = 0.053). Plasma epigallocatechin (EGC) showed a trend to increase (p = 0.066) two hours after capsule intake in the GT + Q vs. the GT + PL-group. There was no significant difference between the groups in GTP content or methylation activity in prostate tissue or RBCs. No liver toxicity was observed. Although our findings are suggestive, further studies are warranted evaluating if Q alters GTP metabolism.

Effects of genotype on TENS effectiveness in controlling knee pain in persons with mild to moderate osteoarthritis.

BACKGROUND: This study examined the extent to which genetic variability modifies Transcutaneous Electrical Nerve Stimulation (TENS) effectiveness in osteoarthritic knee pain. METHODS: Seventy-five participants with knee osteoarthritis were randomly assigned to either: (a) High-frequency TENS, (b) Low-frequency TENS or (c) Transient Placebo TENS. Pain measures were collected pre- and post-treatment. Participants were genotyped on genes implicated in central or peripheral pain pathways: NGFB, NTRK1, EDNRA, EDNRB, EDN1, OPRM1, TAC1, TACR1, BDNF, BDKRB1, 5HTT, COMT, ESR2, IL6 and IL1B. Genetic association using linear regression modelling was performed separately for the transient placebo TENS subjects, and within the High-frequency TENS + Low-frequency TENS participants, including TENS level as a covariate. RESULTS: In the placebo group, SNPs rs165599 (COMT) was significantly associated with an increased heat pain threshold (ß = -1.87; p = .003) and rs6827096 (EDNRA) with an increased resting pain (ß = 2.68; p = .001). Within the treatment groups, TENS effectiveness was reduced by the SNP rs6537485 (EDNRA) minor allele in relationship to mechanical sensation (ß = 184.13; p = 5.5E-9). Individuals with the COMT rs4680 minor allele reported lowered pain at rest after TENS (ß = -42.30; p = .001), with a higher magnitude of pain reduction (28 unit difference) in the low-frequency TENS group compared to the high-frequency TENS group (ß = 28.37; p = .0004). CONCLUSIONS: EDNRA and COMT are implicated in osteoarthritic knee pain and provide a basis for tailoring TENS interventions according to individual characteristics. SIGNIFICANCE: Findings from this study demonstrate that genetic variation within the COMT and EDNRA genes influences the effectiveness of TENS, a non-pharmacologic pain-reduction intervention, in the context of osteoarthritic knee pain. Evidence such as this may contribute to risk models that provide a clinically useful tool for personalizing TENS interventions according to individual characteristics in order to best control pain and maximize functional status.

Structural and biochemical characterization of Rv0187, an O-methyltransferase from Mycobacterium tuberculosis.

Catechol O-methyltransferase (COMT) is widely distributed in nature and installs a methyl group onto one of the vicinal hydroxyl groups of a catechol derivative. Enzymes belonging to this family require two cofactors for methyl transfer: S-adenosyl-l-methionine as a methyl donor and a divalent metal cation for regiospecific binding and activation of a substrate. We have determined two high-resolution crystal structures of Rv0187, one of three COMT paralogs from Mycobacterium tuberculosis, in the presence and absence of cofactors. The cofactor-bound structure clearly locates strontium ions and S-adenosyl-l-homocysteine in the active site, and together with the complementary structure of the ligand-free form, it suggests conformational dynamics induced by the binding of cofactors. Examination of in vitro activities revealed promiscuous substrate specificity and relaxed regioselectivity against various catechol-like compounds. Unexpectedly, mutation of the proposed catalytic lysine residue did not abolish activity but altered the overall landscape of regiospecific methylation.

Both Val158Met Polymorphism of Catechol-O-Methyltransferase Gene and Menstrual Cycle Affect Prepulse Inhibition but Not Attentional Modulation of Prepulse Inhibition in Younger-Adult Females.

Prepulse inhibition (PPI) can be modulated by both the Val158Met (rs4680) polymorphism of the Catechol-O-Methyltransferase (COMT) gene and the menstrual-cycle-related hormone fluctuations, each of which affects the subcortical/cortical dopamine metabolism. PPI can also be modulated by attention. The attentional modulation of PPI (AMPPI) is sensitive to psychoses. Whether the Val158Met polymorphism affects the AMPPI in female adults at different menstrual-cycle phases is unknown. This study examined whether AMPPI and/or PPI are affected by the Val158Met polymorphism in 177 younger-adult females whose menstrual cycles were mutually different across the menstruation, proliferative, or secretory phases. The AMPPI was evaluated by comparing PPI under the condition of the auditory precedence-effect-induced perceptual spatial separation between the prepulse stimulus and a masking noise (PPIPSS) against that under the condition of the precedence-effect-induced perceptual spatial co-location (PPIPSC). The results showed that both the menstrual cycle and the COMT Val158Met polymorphism affected both PPIPSC and PPIPSS, but not the AMPPI (difference between PPIPSS and PPIPSC). Moreover, throughout the menstrual cycle, both PPIPSC and PPIPSS decreased monotonously in Val/Val-carrier participants. However, the decreasing pattern was not overserved in either Met/Met-carrier or Met/Val-carrier participants. Thus, in healthy younger-adult females, PPIPSC and PPIPSS, but not the AMPPI, is vulnerable to changes of ovarian hormones, and the COMT Val158Met polymorphism also has a modulating effect on this menstrual-cycle-dependent PPI variation. In contrast, the AMPPI seems to be more steadily trait-based, less vulnerable to ovarian hormone fluctuations, and may be useful in assisting the diagnosis of schizophrenia in female adults.

COMT and Alpha-Tocopherol Effects in Cancer Prevention: Gene-Supplement Interactions in Two Randomized Clinical Trials.

BACKGROUND: Vitamins are among the most frequently used supplements (48% of US adults). However, little is known about contributions of genetic variation to their efficacy and safety. Multiple pathways link catechol-O-methyltransferase (COMT) to the vitamin E supplement, alpha-tocopherol, and cancer. METHODS: Here we determined if COMT exerted pharmacogenetic effects on cancer prevention in two randomized trials of alpha-tocopherol supplementation. Pharmacogenetic effects of common COMT rs4680 (val158met), which encodes a nonsynonymous valine-to-methionine substitution, were examined in the trial plus a 10-year post-trial follow-up (overall) period of The Women's Genome Health Study (WGHS, N = 23 294), a 10-year alpha-tocopherol and aspirin trial with 10 years post-trial follow-up. Results were validated in a case/control (N = 2396/2235) subset of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC, N = 29 133). The primary outcome was total cancers. Rates of cancer types prevalent in women (colorectal, breast, lung, uterine, and lymphoma/leukemia) were also examined. All statistical tests were two-sided. RESULTS: Random-effects meta-analysis of rs4680 genotype strata, in WGHS and ATBC overall periods, revealed differential alpha-tocopherol effects compared with placebo: met/met (hazard ratio [HR] = 0.88; 95% confidence interval [CI] = 0.80 to 0.97; P = .01), val/met (HR = 0.99; 95% CI = 0.92 to 1.06; P = .74), and val/val (HR = 1.18; 95% CI = 1.06 to 1.31; P = .002) with a statistically significant COMT by alpha-tocopherol interaction (Pinteraction <.001). Timing of effects differed, with stronger effects in WGHS trial and ATBC post-trial. CONCLUSION: Pharmacogenetic analysis of COMT and cancer prevention in two large randomized trials revealed statistically significant COMT by alpha-tocopherol interaction, such that alpha-tocopherol was beneficial among rs4680 met-allele (28.0%), but not val-allele (22.8%) homozygotes. These effects indicate the need for additional studies of genetic variation as a determinant of the benefits and possible harms of over-the-counter supplements, like alpha-tocopherol, used for health promotion.

Genetic polymorphism of catechol-O-methyltransferase modulates the association of green tea consumption and lung cancer.

Tea polyphenols are strong antioxidants, which can be rapidly O-methylated by catechol-O-methyltransferase (COMT). Thus, it is possible that the genetic polymorphism of COMT can modulate the association of green tea consumption and lung cancer. Here, we designed a case-control study to evaluate the combined effect of green tea consumption and COMT genotypes on the risk of lung cancer. A total of 237 lung cancer patients and 474 healthy controls were recruited. Questionnaires were administered to obtain demographic data, smoking status, green tea consumption, fruits and vegetables intake, exposure to cooking fumes, and family history of lung cancer. Genotypes for COMT were identified by PCR. Smoking, green tea consumption, exposure to cooking fumes, and family history of lung cancer were associated with the development of lung cancer. When green tea drinkers carrying COMT HL/LL genotypes were selected as the reference group, drinkers carrying the COMT HH genotype had a higher risk for the development of lung cancer (odds ratio: 1.97, 95% confidence interval: 0.99-3.91). Among the current and ever smokers, the elevated risk for lung cancer was more apparent in green tea drinkers carrying the COMT HH genotype compared with green tea drinkers carrying COMT HL/LL genotypes (odds ratio: 5.84, 95% confidence interval: 1.75-19.45). Green tea drinkers with greater activity of the COMT genotype, whereby polyphenols are effectively excluded, will gain fewer protective benefits against lung cancer development.

Genetic Predictors of Response to Acupuncture for Aromatase Inhibitor-Associated Arthralgia Among Breast Cancer Survivors.

Objective: To evaluate the associations between polymorphisms in two genes, catechol-O-methyltransferase and T-cell leukemia/lymphoma 1 A, and acupuncture-mediated pain reduction among breast cancer survivors with aromatase inhibitor-associated arthralgia. Design, Setting, and Subjects: Biospecimens were obtained from 38 patients enrolled in a clinical trial of acupuncture for aromatase inhibitor-associated arthralgia in postmenopausal hormone receptor-positive breast cancer survivors. Methods: We used polymerase chain reaction to genotype the rs4680 (Val158Met) and rs4633 (His62His) variants in the catechol-O-methyltransferase gene and rs2369049 (A > G) and rs7158782 (A > G) variants in the T-cell leukemia/lymphoma 1 A gene. Response to acupuncture was defined by 30% reduction in end-of-treatment average pain, measured by the Brief Pain Inventory. We used Fisher exact tests to evaluate associations between genotype and treatment response. Results: Among participants, all six (15.8%) subjects who expressed AA in locus rs4680 responded to acupuncture. In a combined analysis, the 18 (47.4%) subjects with the responder genotype at either rs4680 (AA) or rs2369049 (GG or AG) were significantly more likely to respond to acupuncture than those without (77.8% vs 45.0%, P = 0.039). Conclusions: Specific genetic variations at loci rs4680 and rs2369049 are associated with response to acupuncture-type intervention for management of arthralgia. These results serve as a proof of concept for applying a precision medicine framework to the study of cancer pain management.

COMT Genotype and Sensory and Sensorimotor Gating in High and Low Hypnotizable Subjects.

We investigated the association between hypnotizability, COMT polymorphism, P50 suppression ratio, and prepulse inhibition of acoustic startle response (ASR) in 21 high (HH) and 19 low (LH) hypnotizable subjects. The frequency of Met/Met carriers of COMT polymorphysm was higher in HH than in LH group (33.3% versus 10.6%, p = .049). Increased ASR amplitude and latency and decreased prepulse inhibition at 120 ms lead interval were found in the HH compared to the LH group. The effect of COMT genotype on prepulse inhibition was observed in LH group only. No between-group differences in P50 measures were found. The obtained results suppose the participation of dopamine system in mechanisms of hypnotizability and different allocation of attentional resources in HH and LH subjects.

Meta-analysis on the association between genetic polymorphisms and prepulse inhibition of the acoustic startle response.

Sensorimotor gating measured by prepulse inhibition (PPI) of the acoustic startle response (ASR) has been proposed as one of the most promising electrophysiological endophenotypes of schizophrenia. During the past decade, a number of publications have reported significant associations between genetic polymorphisms and PPI in samples of schizophrenia patients and healthy volunteers. However, an overall evaluation of the robustness of these results has not been published so far. Therefore, we performed the first meta-analysis of published and unpublished associations between gene polymorphisms and PPI of ASR. Unpublished associations between genetic polymorphisms and PPI were derived from three independent samples. In total, 120 single observations from 16 independent samples with 2660 study participants and 43 polymorphisms were included. After correction for multiple testing based on false discovery rate and considering the number of analyzed polymorphisms, significant associations were shown for four variants, even though none of these associations survived a genome-wide correction (P<5∗10-8). These results imply that PPI might be modulated by four genotypes - COMT rs4680 (primarily in males), GRIK3 rs1027599, TCF4 rs9960767, and PRODH rs385440 - indicating a role of these gene variations in the development of early information processing deficits in schizophrenia. However, the overall impact of single genes on PPI is still rather small suggesting that PPI is - like the disease phenotype - highly polygenic. Future genome-wide analyses studies with large sample sizes will enhance our understanding on the genetic architecture of PPI.

Effect of catechol-O-methyltransferase Val158Met polymorphism on resting-state brain default mode network after acupuncture stimulation.

The effects of acupuncture can be characterized by clear individual differences. Several revealing studies suggest an underlying role of inherited genetic factor in interindividual variability in response to acupuncture treatment. It remains unclear, however, if the modulation of acupuncture on resting brain function is influenced by genetic factors. Catechol-o-methyltransferase (COMT) Val158Met polymorphism has been shown to regulate the resting brain network, especially in the default mode network (DMN), which is a target area that responds to acupuncture stimulation. Therefore, the present study investigated the effect of COMT Val158Met polymorphism on the modulation of acupuncture in DMN connectivity in healthy Chinese young adults. Using mixed-design ANOVA analysis, we found a significant interactive effect between acupuncture and the COMT gene. For subjects carrying the Val/Met genotype, acupuncture induced decreased DMN connectivity with the left middle frontal gyrus during the post-acupuncture stage compared with the pre-acupuncture stage, which was not observed in Val/Val homozygous subjects. These results demonstrated that during sustained periods after acupuncture stimulation, the brain network is likely under genetic control, and COMT might be a candidate gene that regulates the resting DMN response to acupuncture stimulation.

[Effect of Electroacupuncture on Expression of Catechol-O-methyltransferase in the Inferior Colliculus and Auditory Cortex in Age-related Hearing Loss Guinea Pigs].

OBJECTIVE: To observe the expression of catechol-O-methyltransferase (COMT) in inferior colliculus and auditory cortex of guinea pigs with age-related hearing loss(AHL) induced by D-galactose, so as to explore the possible mechanism of electroacupuncture(EA) underlying preventing AHL. METHODS: Thirty 3-month-old guinea pigs were randomly divided into control group, model group and EA group(n=10 in each group), and ten 18-month-old guinea pigs were allocated as elderly group. The AHL model was established by subcutaneous injection of D-galactose. EA was applied to bilateral "Yifeng"(SJ 17) and "Tinggong"(SI 19) for 15 min in the EA group while modeling, once daily for 6 weeks. After treatment, the latency of auditory brainstem response(ABR) Ⅲ wave was measured by a brain-stem evoked potentiometer. The expressions of COMT in the inferior colliculus and auditory cortex were detected by Western blot. RESULTS: Compared with the control group, the latencies of ABR Ⅲ wave were significantly prolonged and the expressions of COMT in the inferior colliculus and auditory cortex were significantly decreased in the model group and the elderly group(P<0.05). After the treatment, the latency of ABR Ⅲ wave was significantly shortened and the expressions of COMT in the inferior colliculus and auditory cortex were significantly increased in the EA group in comparison with the model group (P<0.05). CONCLUSIONS: EA at "Yifeng" (SJ 17) and "Tinggong" (SI 19) can improve the hearing of age-related deafness in guinea pigs, which may contribute to its effect in up-regulating the expression of COMT in the inferior colliculus and auditory cortex.

A Randomized Controlled Trial of Green Tea Extract Supplementation and Mammographic Density in Postmenopausal Women at Increased Risk of Breast Cancer.

Epidemiologic and animal studies suggest a protective role of green tea against breast cancer. However, the underlying mechanism is not understood. We conducted a randomized, double-blinded, placebo-controlled phase II clinical trial to investigate whether supplementation with green tea extract (GTE) modifies mammographic density (MD), as a potential mechanism, involving 1,075 healthy postmenopausal women. Women assigned to the treatment arm consumed daily 4 decaffeinated GTE capsules containing 1,315 mg total catechins, including 843 mg epigallocatechin-3-gallate (EGCG) for 12 months. A computer-assisted method (Madena) was used to assess MD in digital mammograms at baseline and month 12 time points in 932 completers (462 in GTE and 470 in placebo). GTE supplementation for 12 months did not significantly change percent MD (PMD) or absolute MD in all women. In younger women (50-55 years), GTE supplementation significantly reduced PMD by 4.40% as compared with the placebo with a 1.02% PMD increase from pre- to postintervention (P = 0.05), but had no effect in older women (Pinteraction = 0.07). GTE supplementation did not induce MD change in other subgroups of women stratified by catechol-O-methyltransferase genotype or level of body mass index. In conclusion, 1-year supplementation with a high dose of EGCG did not have a significant effect on MD measures in all women, but reduced PMD in younger women, an age-dependent effect similar to those of tamoxifen. Further investigation of the potential chemopreventive effect of green tea intake on breast cancer risk in younger women is warranted. Cancer Prev Res; 10(12); 710-8. ©2017 AACR.