Protective effect of green tea on the risks of chronic gastritis and stomach cancer

Integrated traditional herbal medicine in the treatment of gastrointestinal disorder: the pattern of use and the knowledge of safety among the Eastern Region Saudi population

BACKGROUND

Herbal medicine is commonly integrated with conventional medicine in Saudi Arabia, especially for the management of digestive disorders. However, the majority of Saudis use herbal remedies without prior consultation with a physician, which raises concerns about their appropriate and safe use. The aim of this study was to assess the level of awareness among the Saudi population regarding the proper utilization and potential adverse effects of frequently used herbs for the treatment of gastrointestinal (GI) diseases.

METHODS

A cross-sectional survey was conducted in Saudi Arabia from January to March 2021. An electronic self-administered questionnaire was distributed.

RESULTS

A total of 543 participants from different age groups, educational levels, and cities across Saudi Arabia completed the study questionnaire. The most commonly used herbs at home by the participants were: myrrh, parsley, black seed, chamomile, mint, anise, clove, and green tea. 57.7% of the participants perceived herbs as safer than conventional medicines; 27.3% reported that using herbal remedies over conventional medicine was a family tradition, and 21.4% used herbs because they were cheaper than conventional medicines.

CONCLUSION

Herbal remedies, including myrrh, parsley, blackseed, chamomile, mint, and anise, are commonly employed for the treatment of gastrointestinal disorders in Saudi Arabia. However, the knowledge level of participants regarding potential side effects and drug-herb interactions was found to be deficient. As such, there is a pressing need for educational campaigns and community awareness programs to elucidate the proper usage of herbal remedies and to caution against their potential adverse effects.

Tea consumption and gastric cancer: a pooled analysis from the Stomach cancer Pooling (StoP) Project consortium

BACKGROUND

Evidence from epidemiological studies on the role of tea drinking in gastric cancer risk remains inconsistent. We aimed to investigate and quantify the relationship between tea consumption and gastric cancer in the Stomach cancer Pooling (StoP) Project consortium.

METHODS

A total of 9438 cases and 20,451 controls from 22 studies worldwide were included. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) of gastric cancer for regular versus non-regular tea drinkers were estimated by one and two-stage modelling analyses, including terms for sex, age and the main recognised risk factors for gastric cancer.

RESULTS

Compared to non-regular drinkers, the estimated adjusted pooled OR for regular tea drinkers was 0.91 (95% CI: 0.85-0.97). When the amount of tea consumed was considered, the OR for consumption of 1-2 cups/day was 1.01 (95% CI: 0.94-1.09) and for >3 cups/day was 0.91 (95% CI: 0.80-1.03). Stronger inverse associations emerged among regular drinkers in China and Japan (OR: 0.67, 95% CI: 0.49-0.91) where green tea is consumed, in subjects with H. pylori infection (OR: 0.68, 95% CI: 0.58-0.80), and for gastric cardia cancer (OR: 0.64, 95% CI: 0.49-0.84).

CONCLUSION

Our results indicate a weak inverse association between tea consumption and gastric cancer.

Peptic ulcer as mediator of the association between risk of gastric cancer and socioeconomic status, tobacco smoking, alcohol drinking and salt intake

BACKGROUND

Peptic ulcer disease (PUD) and gastric cancer (GC) are more prevalent in individuals with low socioeconomic status (SES) and share several risk factors. The aim of this study was to investigate the mediating role of PUD in the association between established risk factors and GC.

METHODS

We conducted a pooled analysis of 12 studies from the Stomach Cancer Pooling Project Consortium, including a total of 4877 GC cases and 11 808 controls. We explored the mediating role of PUD in the association between SES, tobacco smoking, heavy alcohol drinking and salt intake, and GC. Also, we assessed the ORs and 95% CIs of the risk factors and both PUD and GC.

RESULTS

PUD mediated 36% of the smoking effect mainly among men. Other risk factors were only slightly mediated by PUD (SES, 5.3%; heavy alcohol drinking, 3.3%; and salt intake, 2.5%). No significant difference was found when excluding PUD diagnosed within 2 years from GC.

CONCLUSIONS

Our study provides innovative information on the mechanism of stomach mucosal damage leading to PUD and GC, with respect to the effect of tobacco smoking in particular.

Association between the Dietary Inflammatory Index and Gastric Disease Risk: Findings from a Korean Population-Based Cohort Study

Evidence suggests that diets with high pro-inflammatory potential may play a substantial role in the origin of gastric inflammation. This study aimed to examine the association between the energy-adjusted dietary inflammatory index (E-DIITM) and gastric diseases at baseline and after a mean follow-up of 7.4 years in a Korean population. A total of 144,196 participants from the Korean Genome and Epidemiology Study_Health Examination (KoGES_HEXA) cohort were included. E-DII scores were computed using a validated semi-quantitative food frequency questionnaire. Multivariate logistic regression and Cox proportional hazards regression were used to assess the association between the E-DII and gastric disease risk. In the prospective analysis, the risk of developing gastric disease was significantly increased among individuals in the highest quartile of E-DII compared to those in the lowest quartile (HRquartile4vs1 = 1.22; 95% CI = 1.08–1.38). Prospective analysis also showed an increased risk in the incidence of gastritis (HRquartile4vs1 = 1.19; 95% CI = 1.04–1.37), gastric ulcers (HRquartile4vs1 = 1.47; 95% CI = 1.16–1.85), and gastric and duodenal ulcers (HRquartile4vs1 = 1.46; 95% CI = 1.17–1.81) in the highest E-DII quartile compared to the lowest quartile. In the cross-sectional analysis, the E-DII score was not associated with the risk of gastric disease. Our results suggest that a pro-inflammatory diet, indicated by high E-DII scores, is prospectively associated with an increased risk of gastric diseases. These results highlight the significance of an anti-inflammatory diet in lowering the risk of gastric disease risk in the general population.

Revisiting Therapeutic Strategies for H. pylori Treatment in the Context of Antibiotic Resistance: Focus on Alternative and Complementary Therapies

The prevalence of Helicobacter pylori infection remains significant worldwide and it depends on many factors: gender, age, socio-economic status, geographic area, diet, and lifestyle. All successful infectious diseases treatments use antibiotic-susceptibility testing, but this strategy is not currently practical for H. pylori and the usual cure rates of H. pylori are lower than other bacterial infections. Actually, there is no treatment that ensures complete eradication of this pathogen. In the context of an alarming increase in resistance to antibiotics (especially to clarithromycin and metronidazole), alternative and complementary options and strategies are taken into consideration. As the success of antibacterial therapy depends not only on the susceptibility to given drugs, but also on the specific doses, formulations, use of adjuvants, treatment duration, and reinfection rates, this review discusses the current therapies for H. pylori treatment along with their advantages and limitations. As an alternative option, this work offers an extensively referenced approach on natural medicines against H. pylori, including the significance of nanotechnology in developing new strategies for treatment of H. pylori infection.

Alcohol consumption and risk of stomach cancer: A meta-analysis

Stomach cancer is one of the most common cancers in the world. The relationship between alcohol consumption and the risk of stomach cancer remains unclear. Epidemiology studies investigating this relationship have shown inconsistent findings. A meta-analysis was performed to explore the association between alcohol consumption and increased stomach cancer risk. Eighty-one epidemiology studies, including 68 case-control studies and 13 cohort studies, were included in this study. A significant association was found between alcohol consumption and increased risk of stomach cancer (OR = 1.20, 95% CI 1.12-1.27). To explore the source of the significant heterogeneity (p < 0.05, I² = 86%), analysis was stratified by study type (case-control study and cohort study), control type (hospital-based control and population-based control), gender (male, female, and mix), race (White and Asian), region (United States, Sweden, China, Japan), subsite of stomach cancer, and type of alcohol. The stratified analyses found that region and cancer subsite are major sources of the high heterogeneity. The inconsistent results in different regions and different subsites might be related to smoking rates, Helicobacter pylori infection, obesity, and potential genetic susceptibility. The positive association between drinking and increased risk of stomach cancer is consistent in stratified analyses. The dose-response analysis showed a clear trend that a higher daily intake of alcohol is associated with a higher risk of stomach cancer.

Antileishmanial Activity of Lignans, Neolignans, and Other Plant Phenols

Secondary metabolites (SM) from organisms have served medicinal chemists over the past two centuries as an almost inexhaustible pool of new drugs, drug-like skeletons, and chemical probes that have been used in the "hunt" for new biologically active molecules with a "beneficial effect on human mind and body." Several secondary metabolites, or their derivatives, have been found to be the answer in the quest to search for new approaches to treat or even eradicate many types of diseases that oppress humanity. A special place among SM is occupied by lignans and neolignans. These phenolic compounds are generated biosynthetically via radical coupling of two phenylpropanoid monomers, and are known for their multitarget activity and low toxicity. The disadvantage of the relatively low specificity of phenylpropanoid-based SM turns into an advantage when structural modifications of these skeletons are made. Indeed, phenylpropanoid-based SM previously have proven to offer great potential as a starting point in drug development. Compounds such as Warfarin^® (a coumarin-based anticoagulant) as well as etoposide and teniposide (podophyllotoxin-based anticancer drugs) are just a few examples. At the beginning of the third decade of the twenty-first century, the call for the treatment of more than a dozen rare or previously "neglected" diseases remains for various reasons unanswered. Leishmaniasis, a neglected disease that desperately needs new ways of treatment, is just one of these. This disease is caused by more than 20 leishmanial parasites that are pathogenic to humans and are spread by as many as 800 sandfly species across subtropical areas of the world. With continuing climate changes, the presence of Leishmania parasites and therefore leishmaniasis, the disease caused by these parasites, is spreading from previous locations to new areas. Thus, leishmaniasis is affecting each year a larger proportion of the world's population. The choice of appropriate leishmaniasis treatment depends on the severity of the disease and its form of manifestation. The success of current drug therapy is often limited, due in most cases to requiring long hospitalization periods (weeks to months) and the toxicity (side effects) of administered drugs, in addition to the increasing resistance of the parasites to treatment. It is thus important to develop new drugs and treatments that are less toxic, can overcome drug resistance, and require shorter periods of treatment. These aspects are especially important for the populations of developing countries. It was reported that several phenylpropanoid-based secondary metabolites manifest interesting antileishmanial activities and are used by various indigenous people to treat leishmaniasis. In this chapter, the authors shed some light on the various biological activities of phenylpropanoid natural products, with the main focus being on their possible applications in the context of antileishmanial treatment.

Phytoestrogens for Cancer Prevention and Treatment

Phytoestrogens are a large group of natural compounds found in more than 300 plants. They have a close structural similarity to estrogens, which allow them to bind to both estrogen receptors (ER), ERα and ERβ, presenting a weak estrogenic activity. Phytoestrogens have been described as antioxidant, anti-inflammatory, anti-thrombotic, anti-allergic, and anti-tumoral agents. Their role in cancer prevention has been well documented, although their impact on treatment efficiency is controversial. Several reports suggest that phytoestrogens may interfere with the effect of anti-cancer drugs through the regulation of oxidative stress and other mechanisms. Furthermore, some phytoestrogens could exert a protective effect on healthy cells, thus reducing the secondary effects of cancer treatment. In this review, we have studied the recent research in this area to find evidence for the role of phytoestrogens in cancer prevention and therapy efficacy.

FT-NIRS Coupled with PLS Regression as a Complement to HPLC Routine Analysis of Caffeine in Tea Samples

Daily consumption of caffeine in coffee, tea, chocolate, cocoa, and soft drinks has gained wide and plentiful public and scientific attention over the past few decades. The concentration of caffeine in vivo is a crucial indicator of some disorders—for example, kidney malfunction, heart disease, increase of blood pressure and alertness—and can cause some severe diseases including type 2 diabetes mellitus (DM), stroke risk, liver disease, and some cancers. In the present study, near-infrared spectroscopy (NIRS) coupled with partial least-squares regression (PLSR) was proposed as an alternative method for the quantification of caffeine in 25 commercially available tea samples consumed in Oman. This method is a fast, complementary technique to wet chemistry procedures as well as to high-performance liquid chromatography (HPLC) methods for the quantitative analysis of caffeine in tea samples because it is reagent-less and needs little or no pre-treatment of samples. In the current study, the partial least-squares (PLS) algorithm was built by using the near-infrared NIR spectra of caffeine standards prepared in tea samples scanned by a Frontier NIR spectrophotometer (L1280034) by PerkinElmer. Spectra were collected in the absorption mode in the wavenumber range of 10,000–4000 cm⁻¹, using a 0.2 mm path length and CaF₂ sealed cells with a resolution of 2 cm⁻¹. The NIR results for the contents of caffeine in tea samples were also compared with results obtained by HPLC analysis. Both techniques provided good results for predicting the caffeine contents in commercially available tea samples. The results of the proposed study show that the suggested FT-NIRS coupled with PLS regression algorithun has a high potential to be routinely used for the quick and reproducible analysis of caffeine contents in tea samples. For the NIR method, the limit of quantification (LOQ) was estimated as 10 times the error of calibration (root mean square error of calibration (RMSECV)) of the model; thus, RMSEC was calculated as 0.03 ppm and the LOQ as 0.3 ppm.

Green tea (Camellia sinensis) for the prevention of cancer

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects.

OBJECTIVES

To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes.

SEARCH METHODS

We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies.

SELECTION CRITERIA

We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type.

MAIN RESULTS

In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies.

AUTHORS' CONCLUSIONS

Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

Rapid and Sensitive Determination of Methylxanthines in Commercial Brands of Tea Using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry

Recently, chromatographic techniques have the potential to be greener in order to reduce the environmental impact. In this work, a new simple, sensitive, efficient, and green analytical method based on UHPLC-MS has been developed for a quick determination of methylxanthines including caffeine, theobromine, and theophylline in tea. Under the optimum conditions, a baseline separation has been achieved within 30 seconds, using isocratic elution consisting of 90% water and only 10% acetonitrile at 0.5 mL/min flow rate (3 mL acetonitrile per hour). The mass spectrometer was operated with the SIR mode in ESI⁺. The developed method was found to be linear in the range of 0.03–5 μg/mL, with correlation coefficients greater than 0.9995 for the three compounds. The respective values of LOD were found to be 0.025, 0.015, and 0.01 μg/mL for caffeine, theobromine, and theophylline, respectively. The proposed assay was applied to 30 commercial tea samples of different brands. Both caffeine and theobromine were found in all tea samples with maximum concentration in sample no. 15, corresponding to 32.6 and 2.72 mg/g of caffeine and theobromine, respectively. On the contrary, theophylline was not detected at all in most samples. When compared with all previous studies that dealt with the same compounds in different matrices, the developed method was found to be the fastest, allowing high-throughput analyses with more than 100 samples/h. The results prove that the method is suitable for routine analysis of methylxanthines and to distinguish the quality of tea samples of various brands.

Association between tea consumption and depressive symptom among Chinese older adults

Background

Despite accumulating evidence on the protective effect of tea consumption against depression, studies specifically focusing on the elderly population are yet limited. This paper examined the association between the frequency and duration of tea drinking and depressive symptoms of older adults by gender and age groups, based on a nationally representative sample in China.

Method

The study employed the panel data from 2005, 2008/2009, 2011/2012 and 2014 waves of Chinese Longitudinal Healthy Longevity Survey (CLHLS). We used the frequency and consistency of tea drinking behaviors to identify four types of tea consumption amongst Chinese seniors. Depressive symptoms were assessed by a five-item scale. Linear mixed effects models were applied.

Results

We found that consistent and frequent tea-drinking was associated with significantly less depressive symptoms, and such impact was partially mediated by socioeconomic status, health behavior, physical health, cognitive function, and social engagement. However, the association was only significant for males and the oldest-old, rather than females and younger elders.

Conclusions

Consistent and frequent tea-drinking may effectively reduce the risk of depressive symptoms for the Chinese elderly. The promotion of the traditional lifestyle of tea drinking could be a cost-effective way towards healthy aging for China.

Electronic supplementary material

The online version of this article (10.1186/s12877-019-1259-z) contains supplementary material, which is available to authorized users.

Melatonin and (-)-Epigallocatechin-3-Gallate: Partners in Fighting Cancer

We have demonstrated previously that melatonin attenuates hepatotoxicity triggered by high doses of (−)-epigallocatechin-3-gallate (EGCG) in mice. The current work investigated the influence of melatonin on the oncostatic activity of EGCG in two cancer cell lines, wherein melatonin induced an opposite response of p21. In human tongue cancer TCA8113 cells, melatonin-induced p21 and EGCG-mediated formation of quinoproteins were positively associated with the oncostatic effects of melatonin and EGCG. Melatonin-stimulated an increase in p21 which was correlated with a pronounced nuclear translocation of thioredoxin 1 and thioredoxin reductase 1, both of which are known to induce p21 via promoting p53 trans-activation. Melatonin did not influence the EGCG-mediated increase of quinoprotein formation nor did EGCG impair melatonin-induced p21 up-regulation. Co-treatment with both agents enhanced the cell-killing effect as well as the inhibitory activities against cell migration and colony formation. It is known that p21 also plays a powerful anti-apoptotic role in some cancer cells and confers these cells with a survival advantage, making it a target for therapeutic suppression. In human hepatocellular carcinoma HepG2 cells, melatonin suppressed p21 along with the induction of pro-survival proteins, PI3K and COX-2. However, EGCG prevented against melatonin-induced PI3K and COX-2, and melatonin probably sensitized HepG2 cells to EGCG cytotoxicity via down-regulating p21, Moreover, COX-2 and HO-1 were significantly reduced only by the co-treatment, and melatonin aided EGCG to achieve an increased inhibition on Bcl2 and NFκB. These events occurring in the co-treatment collectively resulted in an enhanced cytotoxicity. In addition, the co-treatment also enhanced the inhibitory activities against cell migration and colony formation. Overall, the results gathered from these two cancer cell lines with a divergent p21 response to melatonin show that the various oncostatic activities of melatonin and EGCG together are more robust than each agent alone, suggesting that they may be useful partners in fighting cancer.

Sociodemographic and Lifestyle Factors in Relation to Gastric Cancer in a High-Risk Region of China: A Matched Case-Control Study

Objectives: To explore the role of sociodemographic and lifestyle factors in the development of gastric cancer in a high-risk region of China.Methods: In a case-control study, all newly diagnosed patients with gastric cancer were compared with healthy controls matched (1:1) by sex, age (±3 years), and place of residence during 2013-2017.Results: A total of 622 gastric cancer and 622 healthy controls were included. Larger household size (>4 family members) appeared to decrease gastric cancer risk for Helicobacter pylori-negative ones (odd ratio = 0.43, 95% CI = 0.26-0.70). Similarly, longer refrigerator ownership was associated with a 67% decreased risk in H. pylori-negative group (95% CI = 0.15-0.77). Participants with a family history of gastric cancer had nearly fivefold higher risk (odd ratio = 4.88, 95% CI = 2.49-9.55). Smoking attributed to 83% increased risk (odd ratio = 1.83, 95% CI = 1.19-2.80). Tea consumption dramatically decreased risk in whole study population (odd ratio = 0.28, 95% CI = 0.17-0.45).Conclusions: In summary, family history, smoking, H. pylori-related chronic atrophic gastritis, and H. pylori infection were positively associated with gastric cancer. Whereas, tea consumption and refrigerator use negatively associated with gastric cancer and could be promoted to reduce gastric cancer rate in high-risk populations, especially in the developing regions.

Non-targeted metabolomics reveals diagnostic biomarker in the tongue coating of patients with chronic gastritis

Analysis of the properties of the tongue has been used in traditional Chinese medicine for disease diagnosis. Notably, tongue analysis, which is non-invasive and convenient compared with gastroscopy and pathological examination, can be used to assess chronic gastritis (CG). In order to find potential diagnostic biomarkers and study the metabolic mechanisms of the endogenous small molecules in the tongue coating related to CG, a non-targeted metabolomic analysis method was developed using ultra high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS). It was performed using two different columns in positive and negative ion scanning modes separately. The stability of the samples was evaluated and the age and gender factors of the subjects were excluded to ensure the reliability of the data in this study. Finally, under the four analysis models, 130, 229, 113 and 92 differential compounds were found using multivariate statistical methods respectively. 37 potential biomarkers were putatively identified after removing the duplicate compounds and five potential diagnostic biomarkers were putatively identified by receiver operating characteristic (ROC) curve analysis, including inosine, oleamide, adenosine, N-acetylglucosamine (GlcNAc) and xanthine. The main metabolic pathways associated with CG were purine metabolism, amino acid metabolism, sphingolipid metabolism and energy metabolism, which suggested that oxygen free radicals and energy metabolism were altered in patients with CG. These results provided a potential new basis for the quantitative diagnosis and pathogenesis of CG.

Plant Resources, Chemical Constituents, and Bioactivities of Tea Plants from the Genus Camellia Section Thea

Tea, as one of the most popular beverages with various bioactivities, is commonly produced from the fresh leaves of two widely cultivated tea plants, Camellia sinensis and C. sinensis var. assamica. Both plants belong to the genus Camellia section Thea, which was considered to have 12 species and 6 varieties according to Min's taxonomic system. Most species, except the cultivated species, are known as wild tea plants and have been exploited and utilized to produce tea by the local people of its growing areas. Thus far, six species and varieties have been phytochemically studied, leading to the identification of 398 compounds, including hydrolyzable tannins, flavan-3-ols, flavonoids, terpenoids, alkaloids, and other phenolic and related compounds. Various beneficial health effects were reported for tea and its components, involving antioxidant, antitumor, antimutagenic, antidiabetic, hypolipidemic, anti-inflammatory, antimicrobial, antiviral, antifungal, neuroprotective, hepatoprotective, etc. In this review, the geographical distribution of tea plants and the chemical constituents (1-398) reported from the genus Camellia section Thea and some tea products (green, black, oolong, and pu-erh tea) that have ever been studied between 1970 and 2018 have been summarized, taking species as the main hint, and the main biological activities are also discussed.

Risk Factors of Gastric Cancer in High-Risk Region of China: A Population-Based Case-control Study

Background: The reason for the high incidence of gastric cancer (GC) in Xianyou County of China was largely unknown. We aimed to explore the potential sociodemographic risk factors and their associations to GC. Methods: A population-based case-control study was conducted during March 2013 and April 2016 in Xianyou County. All newly diagnosed patients of GC were recruited as cases, while controls were selected by matching for cases’ sex, age (± 3 years) and the place of residence. Results: A total of 523 GC cases and 523 matched healthy controls were included in the final analysis with mean age of 66.27±8.81 years for cases and 66.31±8.83 years for controls, respectively. Participants with low socioeconomic status were observed with higher GC risk compared to those in high socioeconomic status (adjusted OR=2.10, 95% CI: 1.13-3.89). Compared to those regularly drink green tea, patients did not have this dietary habit had nearly 3-fold increased GC risk (adjusted OR=2.91, 95% CI: 1.38-6.13). Other dietary habit, including consumption of hard food, omission of breakfast, consumption of pickled vegetables 30 years ago, overeating were all associated with increased risk of GC. Interaction effect were found. Patients in low socioeconomic status and skipped breakfast had 10-fold higher risk of GC compared to reference group in high socioeconomic status and eat breakfast regularly (OR=10.71, 95% CI: 5.19-22.10). Furthermore, patients in low socioeconomic status and consumed pickled vegetable 30 years ago had 6-fold higher risk of GC compared to those in high socioeconomic status but did not intake pickled vegetables 30 years ago (OR=6.11, 95% CI: 3.87-9.66). Conclusion: High incidence of GC risk in Xianyou County might be partly attributed to various sociodemographic factors. Specific prevention effort could be target on population in low socioeconomic status combined with habit of breakfast omission or intake of pickled vegetables.

(-)-Epigallocatechin Gallate (EGCG) Enhances the Sensitivity of Colorectal Cancer Cells to 5-FU by Inhibiting GRP78/NF-κB/miR-155-5p/MDR1 Pathway

Green tea accounts for approximately 20% of the world's total tea yield. (-)-Epigallocatechin gallate (EGCG) is an active catechin in green tea, which suppresses tumor growth and enhances drug sensitivity in various cancers, but the molecular mechanism is still unclear. Chemotherapy drugs, such as 5-fluorouracil (5-FU), are a common strategy for clinical treatment of cancer patients; however, the lower response rate caused by prolonged use becomes the main reason for tumor recurrence. Therefore, discovering a safe and effective chemo-sensitizer is an urgent task required to be solved. Here, we report that EGCG reinforces the sensitivity of colon cancer cells to 5-FU, and the IC₅₀ values of 5-FU is decreased from 40 ± 4.2 μM to 5 ± 0.36 μM in one human colon carcinoma cell line-HCT-116, and from 150 ± 6.4 μM to 11 ± 0.96 μM in the other human colon carcinoma cell line-DLD1 when these cells are cotreated with 50 μM EGCG. Consistently, compared to 5-FU or EGCG treatment alone, the combination of both significantly promotes cancer cell apoptosis and DNA damage. Further mechanism research reveals that treatment of colorectal cancer (CRC) with 50 μM EGCG inhibits GRP78 expression, activates the NF-κB (2.55 ± 0.05-fold for HCT-116 and 2.27 ± 0.08-fold for DLD1) pathway, and enhances miR-155-5p (2.12 ± 0.02-fold for HCT-116 and 2.01 ± 0.01-fold for DLD1) level. The elevated miR-155-5p strongly suppresses target gene MDR1 expression, which blocks the efflux of 5-FU. The accumulation of 5-FU resulted in caspase-3 and PARP activation, Bcl-2 reduction, and Bad increase, which ultimately lead to cancer cell apoptosis. Overall, our data show that EGCG may be act as a novel chemo-sensitizer, and the GRP78/NF-κB/miR-155-5p/MDR1 pathway plays a vital role in EGCG enhancing the sensitivity of colorectal cancer to 5-FU.

Zinc transporter SLC39A11 polymorphisms are associated with chronic gastritis in the Korean population: the possible effect on spicy food intake

Herein, we hypothesized that ZIP11 variants would be important risk factors for chronic gastritis and that there would be an interaction effect of the relationship between their variants and spicy food intake on the development of chronic gastritis. Participants in this cross-sectional study (n = 3882 + 252) were recruited from a cohort of the Korean Genome and Epidemiology Study in 2001. Age, sex, education, smoking and drinking status, exercise, stress, and income level of all participants were determined by a questionnaire. Demographic and anthropometric data were collected. Fasting blood samples were collected to determine the serum levels of glucose, insulin, total bilirubin, total cholesterol, high-density lipoprotein cholesterol, and triglycerides. The presence of chronic gastritis was defined as a confirmed diagnosis by a physician. Food consumption was determined using a semiquantitative food frequency questionnaire. We found 8 different single nucleotide polymorphisms (SNPs) that are significantly different between subjects without gastritis and those with gastritis. Of these 8 SNPs, 3 SNP (rs17183225 [C/T], rs17780814 [A/C], and rs17780820 [A/G]) are closely located in the intronic region of zinc transporter SLC39A11, commonly known as ZIP11, and show linkage disequilibrium (D' = 1.0). We also found that participants with (TCA + TCG) haplotype of ZIP11 at high levels of dietary intake of spicy foods show a significantly increasing tendency in the odds of having chronic gastritis when compared with those with CAA haplotype (odds ratio, 2.620; 95% confidence interval, 1.207-5.689). The data indicate positive associations between higher meal frequency and lower spicy food preference and gastritis. In conclusion, we found that zinc transporter gene ZIP11 is associated with chronic gastritis in the Korean population and it may interact with spicy food, which suggests ZIP11 as a therapeutic target for precision nutrition.

Association between tea consumption and risk of cognitive disorders: A dose-response meta-analysis of observational studies

Background

The epidemiological evidence for a dose-response relationship between tea consumption and risk of cognitive disorders is sparse. The aim of the study was to summarize the evidence for the association of tea consumption with risk of cognitive disorders and assess the dose-response relationship.

Methods

We searched electronic databases of Pubmed, Embase, and Cochrane Library (from 1965 to Jan 19, 2017) for eligible studies that published in the international journals. A random-effects model was used to pool the most adjusted odds ratios (ORs) and the corresponding 95% confidence intervals (CIs).

Results

Seventeen studies involving 48,435 participants were included in our study. The meta-analysis showed that a higher tea consumption was associated with a significant reduction in the risk of cognitive disorders (OR=0.73, 95% CI: 0.65-0.82). When considering the specific types of tea consumption, the significantly inverse association is only found in green tea consumption (OR=0.64, 95% CI: 0.53-0.77) but not in black/oolong tea consumption (OR=0.75, 95% CI: 0.55-1.01). Dose-response meta-analysis indicated that tea consumption is linearly associated with a reduced risk of cognitive disorders. An increment of 100 ml/day, 300 ml/day, and 500 ml/day of tea consumption was associated with a 6% (OR=0.94, 95% CI: 0.92-0.96), 19% (OR=0.81, 95% CI: 0.74-0.88), and 29% (OR=0.71, 95% CI: 0.62-0.82) lower risk of cognitive disorders.

Conclusions

Tea consumption is inversely and linearly related to the risk of cognitive disorders. More studies are needed to further confirm our findings.

Association between green tea intake and risk of gastric cancer: a systematic review and dose-response meta-analysis of observational studies

OBJECTIVE

To examine and quantify the potential dose-response relationship between green tea intake and the risk of gastric cancer.

DESIGN

We searched PubMed, EMBASE, Web of Science, CBM, CNKI and VIP up to December 2015 without language restrictions.

SETTING

A systematic review and dose-response meta-analysis of observational studies.

SUBJECTS

Five cohort studies and eight case-control studies.

RESULTS

Compared with the lowest level of green tea intake, the pooled relative risk (95 % CI) of gastric cancer was 1·05 (0·90, 1·21, I 2=20·3 %) for the cohort studies and the pooled OR (95 % CI) was 0·84 (0·74, 0·95, I 2=48·3 %) for the case-control studies. The pooled relative risk of gastric cancer was 0·79 (0·63, 0·97, I 2=63·8 %) for intake of 6 cups green tea/d, 0·59 (0·42, 0·82, I 2=1·0 %) for 25 years of green tea intake and 7·60 (1·67, 34·60, I 2=86·5 %) for drinking very hot green tea.

CONCLUSIONS

Drinking green tea has a certain preventive effect on reducing the risk of gastric cancer, particularly for long-term and high-dose consumption. Drinking too high-temperature green tea may increase the risk of gastric cancer, but it is still unclear whether high-temperature green tea is a risk factor for gastric cancer. Further studies should be performed to obtain more detailed results, including other gastric cancer risk factors such as smoking and alcohol consumption and the dose of the effective components in green tea, to provide more reliable evidence-based medical references for the relationship between green tea and gastric cancer.

The therapeutic effect of zerumbone on chronic gastritis via antioxidant mechanisms

Effects of zerumbone on chronic gastritis remain unclear. The purpose of this study was to investigate the mechanism of the protective effect of zerumbone on the treatment of chronic gastritis in rats. The animal models of chronic gastritis in rats were established, and the surface damage of gastric mucosa was observed by gross anatomy; the changes of gastric mucosal tissue and surface morphology were observed by pathological sections of gastric mucosal tissues; the expressions of heme oxygenase-1 (HO-1) and nuclear factor E2-related factor 2 (Nrf-2) proteins of gastric mucosal tissues in each group were detected by western blot analysis; the activities of superoxide dismutase (SOD) and catalase (CAT) as well as the contents of reduced glutathione (GSH) and malondialdehyde (MDA) in gastric mucosal tissues were detected by kits. The results indicated that zerumbone could significantly relieve red and swelling as well as erosion of the gastric mucosal tissues in rats with chronic gastritis; zerumbone could significantly ameliorate the loose arrangement of cells in the lamina propria of gastric mucosa, epithelial cell deformation and abscission, and inflammatory cell infiltration. The results of western blot analysis showed that compared with the model group, zerumbone could significantly upregulate the expression of HO-1 and Nrf-2 in gastric mucosal tissues. Compared with the model group, the activities of SOD and CAT as well as GSH levels in gastric mucosal tissues of rats in the zerumbone groups were obviously increased, but MDA contents were significantly decreased. Zerumbone has a protective effect on chronic gastritis in rats, which is achieved by improving the antioxidant capacity of gastric mucosal tissues through inhibiting lipid peroxidation.

Functional Characterization of a New Tea (Camellia sinensis) Flavonoid Glycosyltransferase

Tea (Camellia sinensis) is an important commercial crop, in which the high content of flavonoids provides health benefits. A flavonoid glycosyltransferase (CsUGT73A20), belonging to cluster IIIa, was isolated from tea plant. The recombinant CsUGT73A20 in Escherichia coli exhibited a broad substrate tolerance toward multiple flavonoids. Among them, kaempferol was the optimal substrate compared to quercetin, myricetin, naringenin, apigenin, and kaempferide. However, no product was detected when UDP-galactose was used as the sugar donor. The reaction assay indicated that rCsUGT73A20 performed multisite glycosidation toward flavonol compounds, mainly forming 3-O-glucoside and 7-O-glucoside in vitro. The biochemical characterization analysis of CsUGT73A20 showed more K7G product accumulated at pH 8.0, but K3G was the main product at pH 9.0. Kinetic analysis demonstrated that high pH repressed the glycosylation reaction at the 7-OH site in vitro. Besides, the content of five flavonol-glucosides was increased in CsUGT73A20-overexpressing tobaccos (Nicotiana tabacum).

Pharmacological Intervention through Dietary Nutraceuticals in Gastrointestinal Neoplasia

Neoplastic conditions associated with gastrointestinal (GI) tract are common worldwide with colorectal cancer alone accounting for the third leading rate of cancer incidence. Other GI malignancies such as esophageal carcinoma have shown an increasing trend in the last few years. The poor survival statistics of these fatal cancer diseases highlight the need for multiple alternative treatment options along with effective prophylactic strategies. Worldwide geographical variation in cancer incidence indicates a correlation between dietary habits and cancer risk. Epidemiological studies have suggested that populations with high intake of certain dietary agents in their regular meals have lower cancer rates. Thus, an impressive embodiment of evidence supports the concept that dietary factors are key modulators of cancer including those of GI origin. Preclinical studies on animal models of carcinogenesis have reflected the pharmacological significance of certain dietary agents called as nutraceuticals in the chemoprevention of GI neoplasia. These include stilbenes (from red grapes and red wine), isoflavones (from soy), carotenoids (from tomatoes), curcuminoids (from spice turmeric), catechins (from green tea), and various other small plant metabolites (from fruits, vegetables, and cereals). Pleiotropic action mechanisms have been reported for these diet-derived chemopreventive agents to retard, block, or reverse carcinogenesis. This review presents a prophylactic approach to primary prevention of GI cancers by highlighting the translational potential of plant-derived nutraceuticals from epidemiological, laboratory, and clinical studies, for the better management of these cancers through consumption of nutraceutical rich diets and their intervention in cancer therapeutics.

Functional Characterization of Tea (Camellia sinensis) MYB4a Transcription Factor Using an Integrative Approach

Green tea (Camellia sinensis, Cs) abundantly produces a diverse array of phenylpropanoid compounds benefiting human health. To date, the regulation of the phenylpropanoid biosynthesis in tea remains to be investigated. Here, we report a cDNA isolated from leaf tissues, which encodes a R2R3-MYB transcription factor. Amino acid sequence alignment and phylogenetic analysis indicate that it is a member of the MYB4-subgroup and named as CsMYB4a. Transcriptional and metabolic analyses show that the expression profile of CsMYB4a is negatively correlated to the accumulation of six flavan-3-ols and other phenolic acids. GFP fusion analysis shows CsMYB4a's localization in the nucleus. Promoters of five tea phenylpropanoid pathway genes are isolated and characterized to contain four types of AC-elements, which are targets of MYB4 members. Interaction of CsMYB4a and five promoters shows that CsMYB4a decreases all five promoters' activity. To further characterize its function, CsMYB4a is overexpressed in tobacco plants. The resulting transgenic plants show dwarf, shrinking and yellowish leaf, and early senescence phenotypes. A further genome-wide transcriptomic analysis reveals that the expression levels of 20 tobacco genes involved in the shikimate and the phenylpropanoid pathways are significantly downregulated in transgenic tobacco plants. UPLC-MS and HPLC based metabolic profiling reveals significant reduction of total lignin content, rutin, chlorogenic acid, and phenylalanine in CsMYB4a transgenic tobacco plants. Promoter sequence analysis of the 20 tobacco genes characterizes four types of AC-elements. Further CsMYB4a-AC element and CsMYB4a-promoter interaction analyses indicate that the negative regulation of CsMYB4a on the shikimate and phenylpropanoid pathways in tobacco is via reducing promoter activity. Taken together, all data indicate that CsMYB4a negatively regulates the phenylpropanoid and shikimate pathways. Highlight: A tea (Camellia sinensis) MYB4a is characterized to encode a R2R3-MYB transcription factor. It is shown to repressively control the phenylpropanoid and shikimate pathway.

Nutrition and Helicobacter pylori: Host Diet and Nutritional Immunity Influence Bacterial Virulence and Disease Outcome

Helicobacter pylori colonizes the stomachs of greater than 50% of the world's human population making it arguably one of the most successful bacterial pathogens. Chronic H. pylori colonization results in gastritis in nearly all patients; however in a subset of people, persistent infection with H. pylori is associated with an increased risk for more severe disease outcomes including B-cell lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma) and invasive adenocarcinoma. Research aimed at elucidating determinants that mediate disease progression has revealed genetic differences in both humans and H. pylori which increase the risk for developing gastric cancer. Furthermore, host diet and nutrition status have been shown to influence H. pylori-associated disease outcomes. In this review we will discuss how H. pylori is able to create a replicative niche within the hostile host environment by subverting and modifying the host-generated immune response as well as successfully competing for limited nutrients such as transition metals by deploying an arsenal of metal acquisition proteins and virulence factors. Lastly, we will discuss how micronutrient availability or alterations in the gastric microbiome may exacerbate negative disease outcomes associated with H. pylori colonization.

Dietary Intervention of Artemisia and Green Tea Extracts to Rejuvenate Helicobacter pylori-Associated Chronic Atrophic Gastritis and to Prevent Tumorigenesis

OBJECT

As nonmicrobial dietary approach is capable of controlling Helicobacter pylori infection, we evaluated the efficacy of long-term dietary administration of Artemisia and/or green tea extracts on H. pylori-initiated, high-salt-promoted chronic atrophic gastritis and gastric tumorigenesis mouse model.

METHODS

Helicobacter pylori-infected and high-salt-diet-administered C57BL/6 mice were administered with Artemisia extracts (MP group) and/or green tea extracts (GT group) for 36 weeks in addition to the control group (ES group, gastroprotective drug, ecabet sodium 30 mg/kg, diet pellet). Gross and pathological gastric lesions were evaluated after 24 and 36 weeks, respectively, and their underlying molecular changes were measured in gastric homogenates. Detailed mechanisms were further evaluated in in vitro cell models.

RESULTS

The erythematous and nodular changes and mucosal ulcerative and erosive lesions were noted in the control group at 24 weeks. MP, GT, MPGT, and ES groups all showed significantly ameliorated pathologic lesion compared to the control group (p < .05). After the 36 weeks, scattered nodular masses with some central ulcers and thin gastric surface were noted in the control stomach, whereas no tumorous lesion and milder atrophic changes were observed in all MP, GT, and MPGT groups except ES group (p < .05). On molecular analysis, increased expressions of COX-2, TNF-α, IL-6, lipid peroxide, and activated STAT3 relevant to H. pylori infection were significantly decreased with MPGT administration (p < .01), whereas HSP70 was significantly increased. PGDH expressions, core tumor suppressor involved in carcinogenesis, were significantly decreased with H. pylori infection (p < .05), but significantly increased in MPGT group (p < .05). Increased mucosal apoptotic index noted in the control group was significantly decreased with MP and/or GT along with significantly preserved gastric gastroprotective mediators (p < .01) such as mucins, HSP27, and HSP70. H. pylori-induced serum TNF-α and NF-κB activations were significantly decreased with MPGT administration (p < .05).

CONCLUSION

Long-term dietary intake of MP and/or GT can be an effective strategy either to rejuvenate H. pylori atrophic gastritis or to suppress tumorigenesis.

Establishment of drug delivery system nanocapsulated with an antioxidant (+)-catechin hydrate and sodium meta borate chelator against sodium fluoride induced oxidative stress in rats

Oxidative stress a major cause of fluoride induced toxicity and mitochondrial impairment in common in experimental rats during chronic exposure of fluoride. Attempts have been made in the present experiment to diminish oxidative damage, combined therapy with (+)-catechin hydrate (an antioxidant) and sodium meta borate (chelator) were used. Fluoride intoxication in rats was performed by using 13mg/kg NaF and both antioxidant CH and chelator SMB were used at a concentration of 8.98μM/kg body weight. Mixture of CH and SMB in free or in PLGA nanocapsule encapsulated form were prepared. The efficacies of those formulations were tested in combating free radical mediated oxidative insult produced by sodium fluoride (NaF). The amalgamated therapy used in this experiment was shown to reduce fluoride levels in liver, brain and kidney from 9.5, 5.5, 6.3μg/g to 4.6, 2, 2.6μg/g, respectively. Our result indicated that the combined chelator and antioxidant therapy in nanocapsulated drug delivery system could provide a projection in combating fluoride induced mitochondrial impairment in rat model.

Landscape of dietary factors associated with risk of gastric cancer: A systematic review and dose-response meta-analysis of prospective cohort studies

BACKGROUND

The associations between dietary factors and gastric cancer risk have been analysed by many studies, but with inconclusive results. We conducted a meta-analysis of prospective studies to systematically investigate the associations.

METHODS

Relevant studies were identified through searching Medline, Embase, and Web of Science up to June 30, 2015. We included prospective cohort studies of intake of dietary factors with risk estimates and 95% confidence intervals for gastric cancer.

RESULTS

Seventy-six prospective cohort studies were eligible and included in the analysis. We ascertained 32,758 gastric cancer cases out of 6,316,385 participants in relations to intake of 67 dietary factors, covering a wide ranging of vegetables, fruit, meat, fish, salt, alcohol, tea, coffee, and nutrients, during 3.3 to 30 years of follow-up. Evidence from this study indicates that consumption of total fruit and white vegetables, but not total vegetables, was inversely associated with gastric cancer risk. Both fruit and white vegetables are rich sources of vitamin C, which showed significant protective effect against gastric cancer by our analysis too. Furthermore, we found concordant positive associations between high-salt foods and gastric cancer risk. In addition, a strong effect of alcohol consumption, particularly beer and liquor but not wine, on gastric cancer risk was observed compared with nondrinkers. Dose-response analysis indicated that risk of gastric cancer was increased by 12% per 5 g/day increment of dietary salt intake or 5% per 10 g/day increment of alcohol consumption, and that a 100 g/day increment of fruit consumption was inversely associated with 5% reduction of risk.

CONCLUSION

This study provides comprehensive and strong evidence that there are a number of protective and risk factors for gastric cancer in diet. Our findings may have significant public health implications with regard to prevention of gastric cancer and provide insights into future cohort studies and the design of related clinical trials.

Hereditary diffuse gastric cancer--An overview

The incidence of gastric cancer varies by up to ten fold throughout the world, and the geographic distribution of hereditary cases is not well explored. Familial clustering is seen in 10% of cases, and approximately 3% of all gastric cancers develop due to hereditary diffuse gastric cancer (HDGC). In this review, the characteristics of HDGC are presented according to molecular particularities, geographic distribution, and other parameters. Based on our experience and the data from the literature, we discuss the possibility of applying a mutation signature (spectrum) study and adductomic approaches to a comparative carcinogenesis of HDGC. We also provide a comprehensive, up-to-date review of genetic counseling and criteria for screening and surveillance of eligible families.

Association of risk of gastric cancer and consumption of tobacco, alcohol and tea in the Chinese population

This study aimed at summarizing epidemiological research findings on associations between tobacco, alcohol and tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed, Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases and reference lists of review papers for all studies published in English or Chinese languages. Information extracted, via two independent researchers, from retrieved articles included first author, year of publication, study design, sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95% confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematic search found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in terms of pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI: 1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies ranged from 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses. All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The study revealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while tea drinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should be interpreted with caution given the fact that most of the included studies were based on a retrospective design and heterogeneity among studies was relatively high.

Medicinal plants in the treatment of Helicobacter pylori infections

CONTEXT

Helicobacter pylori is a small, spiral, Gram-negative bacillus that plays a role in the pathogenesis of a number of diseases ranging from asymptomatic gastritis to gastric cancer. Schedule compliance, antibiotic drug resistance, and side-effects of triple or quadruple therapy have led to research for novel candidates from plants.

OBJECTIVE

The purpose of this paper is to review the most potent medicinal plants of recently published literature with anti-H. pylori activity. For centuries, herbals have been used by traditional healers around the world to treat various gastrointestinal tract disorders such as dyspepsia, gastritis, and peptic ulcer disease. The mechanism of action by which these botanicals exert their therapeutic properties has not been completely and clearly elucidated. Anti-H. pylori properties may be one of the possible mechanisms by which gastroprotective herbs treat gastrointestinal tract disorders.

MATERIALS AND METHODS

Electronic databases such as PubMed, Google scholar, EBSCO, and local databases were explored for medicinal plants with anti-H. pylori properties between 1984 and 2013 using key words "medicinal plants" and "Helicobacter pylori" or "anti-Helicobacter pylori".

RESULTS

A total of 43 medicinal plant species belonging to 27 families including Amaryllidaceae, Anacardiaceae, Apiaceae, Apocynaceae, Asclepiadoideae, Asteraceae, Bignoniaceae, Clusiaceae, Chancapiedra, Combretaceae, Cyperaceae, Euphorbiaceae, Fabaceae, Geraniaceae, Lamiaceae, Lauraceae, Lythraceae, Menispermaceae, Myristicaceae, Myrtaceae, Oleaceae, Papaveraceae, Plumbaginaceae, Poaceae, Ranunculaceae, Rosaceae, and Theaceae were studied as herbs with potent anti-H. pylori effects.

CONCLUSION

Traditional folk medicinal use of some of these plants to treat gastric infections is substantiated by the antibacterial activity of their extracts against H. pylori.

A case-control study of stomach cancer in relation to Camellia sinensis in China

OBJECTIVE

The purpose of our study was to investigate the association between green tea (Camellia sinensis) drinking habits and risk of stomach cancer in China.

METHOD

A 1:2 matched hospital-based case-control study including 160 cases and 320 controls was conducted. A self-designed questionnaire was used to collect information on possible risk factors of stomach cancer, and to assess the green tea drinking habit. Conditional logistic regression was used to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

RESULT

Our study proposed that green tea was associated with risk of stomach cancer. Regular drinking (OR = 0.72), larger amount of consumption (≥35 g/week) (OR = 0.53) were protective factors. Among regular tea drinkers, lower temperature and longer interval between tea being poured and drunk also reduced the risk. Moreover, a strong agreement was found between temperature at which tea was drunk and tea interval (Correlation coefficient p value = 0.73).

CONCLUSION

Habits of green tea drinking, including regular drinking, larger amount of consumption, lower temperature and longer interval were strongly associated with a lower risk of stomach cancer.

Efficient extraction of major catechins in Camellia sinensis leaves using green choline chloride-based deep eutectic solvents

Choline chloride-based deep eutectic solvents (DESs), composed of alcohols, organic acids and saccharides, were used as green solvents for extraction of major catechins inCamellia sinensisleaves.

Color measurement of tea leaves at different drying periods using hyperspectral imaging technique

This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb*) and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380–1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR) models. Competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR]) were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (r_p) of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs) ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

Health education and guidance improve preventive and therapeutic effects on chronic gastritis

Chronic gastritis (CG) is a disease frequently encountered in gastroenterology department, and it is characterized by high incidence, longer course and easy relapse. Therefore, CG has a severe impact on people's health and quality of life. Simple drug treatment often cannot achieve desired efficacy, and the curative effect is unsustained. This situation is closely related to the lack of awareness and attention of this disease. Thus, strengthening health education and guidance in patients is very important for improving the clinical control effect for this disease. This review aims to review the significance of health education and guidance for CG and propose specific methods to provide a reference for clinical treatment of this disease.

Evaluation and clinical significance of the stomach age model for evaluating aging of the stomach-a multicenter study in China

Background

A higher prevalence of chronic atrophic gastritis (CAG) occurs in younger adults in Asia. We used Stomach Age to examine the different mechanisms of CAG between younger adults and elderly individuals, and established a simple model of cancer risk that can be applied to CAG surveillance.

Methods

Stomach Age was determined by FISH examination of telomere length in stomach biopsies. Δψm was also determined by flow cytometry. Sixty volunteers were used to confirm the linear relationship between telomere length and age while 120 subjects were used to build a mathematical model by a multivariate analysis. Overall, 146 subjects were used to evaluate the validity of the model, and 1,007 subjects were used to evaluate the relationship between prognosis and Δage (calculated from the mathematical model). ROC curves were used to evaluate the relationship between prognosis and Δage and to determine the cut-off point for Δage.

Results

We established that a tight linear relationship between the telomere length and the age. The telomere length was obvious different between patients with and without CAG even in the same age. Δψm decreased in individuals whose Stomach Age was greater than real age, especially in younger adults. A mathematical model of Stomach Age (real age + Δage) was successfully constructed which was easy to apply in clinical work. A higher Δage was correlated with a worse outcome. The criterion of Δage >3.11 should be considered as the cut-off to select the subgroup of patients who require endoscopic surveillance.

Conclusion

Variation in Stomach Age between individuals of the same biological age was confirmed. Attention should be paid to those with a greater Stomach Age, especially in younger adults. The Δage in the Simple Model can be used as a criterion to select CAG patients for gastric cancer surveillance.

Role of the flavan-3-ol and galloyl moieties in the interaction of (-)-epigallocatechin gallate with serum albumin

The principal green tea polyphenol, (-)-epigallocatechin-3-O-gallate (EGCg), may provide chemoprotection against conditions ranging from cardiovascular disease to cancer. Binding to plasma proteins stabilizes EGCg during its transport to targeted tissues. This study explored the details EGCg binding to bovine serum albumin. Both fluorescence lifetime and intensity data showed that the hydrophobic pocket between subdomains IIA and IIIA is the binding site for EGCg. Fluorescence and circular dichroism were used to establish the roles of the flavan-3-ol and galloyl moieties of the EGCg in binding and to demonstrate a binding-dependent conformational change in the protein. Competitive binding experiments confirmed the location of binding, and molecular modeling identified protein residues that play key roles in the interaction. This model of EGCg-BSA interactions improves the understanding of the likely physiological fate of this green tea-derived bioactive polyphenol.

The characterization of caffeine and nine individual catechins in the leaves of green tea (Camellia sinensis L.) by near-infrared reflectance spectroscopy

Near-infrared reflectance spectroscopy (NIRS) was used to determine the contents of caffeine and nine individual catechins in tea leaves. A total of 665 samples were scanned by NIRS, and also by high performance liquid chromatography coupled to a diode array detector to determine the contents of caffeine and nine individual catechins. The calibration models for caffeine, EGC, C, EGCG, EC, ECG, and total catechins had high r(2) (more than 0.90) and RSP (the ratio of standard deviation of reference data to SEP(C) in the external validation set) values (more than 4.1), indicating a good correlation between reference values and NIRS predicted values. In contrast, the calibration models of GC and EGCG-3Me had low r(2) and RSP values (below 0.8 and 2.0). Therefore, these results suggest that NIRS could be applied for the rapid determination of the contents of caffeine, EGC, C, EGCG, EC, ECG, and total catechins in tea leaves for breeding programs that develop high-quality tea plants.