Effects and mechanisms of tea for the prevention and management of cancers: An updated review.

Tea is a traditional and popular beverage worldwide, and the consumption of tea has been demonstrated to possess many health benefits, such as cardiovascular protection, anti-obesity, anti-diabetes, and anticancer. Epidemiological studies have shown that the consumption of tea is inversely associated with the risk of several cancers. In addition, experimental studies have revealed that the anticancer actions of tea are mainly attributed to tea polyphenols, such as epigallocatechin-3-gallate and theaflavins. Both in vitro and in vivo studies have demonstrated that the possible anticancer mechanisms are the inhibition on proliferation, anti-angiogenesis, induction of apoptosis, suppression on metastasis, inhibition on cancer stem cells, and modulation on gut microbiota. Its synergetic anticancer effects with drugs or other compounds could promote anticancer therapies. Furthermore, clinical trials have elucidated that intervention of tea phytochemicals is effective in the prevention of several cancers. This paper is an updated review for the prevention and management of cancers by tea based on the findings from epidemiological, experimental and clinical studies, and special attention is paid on the mechanisms of action.

Comparison of Antioxidant Activities of Different Grape Varieties.

Grapes are widely consumed in the world, and different grape varieties could exhibit distinctly different antioxidant activities. In this study, the free radical-scavenging and antioxidant activities of lipophilic, hydrophilic, and insoluble-bound fractions from 30 grape varieties were evaluated by ferric-reducing antioxidant powers (FRAP), Trolox equivalent antioxidant capacities (TEAC), total phenolic contents (TPC), and total flavonoid contents (TFC). The results indicated that the 30 grape varieties exhibited diverse FRAP values (1.289⁻11.767 µmol Fe(II)/g FW), TEAC values (0.339⁻4.839 µmol Trolox/g FW), TPC values (0.294⁻1.407 mg GAE/g FW) and TFC values (0.082⁻0.132 mg QE/g FW). Several grapes, such as Pearl Black Grape (Xinjiang), Summer Black Grape (Shaanxi), Pearl Green Grape (Xinjiang), Seedless Green Grape (Xinjiang), and Seedless Red Grape (Yunnan), exhibited strong free radical-scavenging and antioxidant activities, which could be consumed as good sources of natural antioxidants to prevent several diseases induced by oxidative stress, such as cardiovascular disease and cancer. Furthermore, several antioxidants were identified and quantified, including caffeic acid, catechin gallate, epicatechin, gallic acid, protocatechuic acid and rutin, which could contribute to the antioxidant activities of grapes.

Potential of Grape Wastes as a Natural Source of Bioactive Compounds.

Grapes are widely used in the wine and juice industries, which can lead to massive amounts of waste, mostly grape peels and seeds. The antioxidant capacities, total phenolic and flavonoid contents and phenolic profiles of peels and seeds from 30 grape varieties were systemically assessed. The antioxidant activities of fat-soluble, water-soluble and insoluble-bound fractions of grape peels and seeds were evaluated using ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays, and their total phenolic contents and total flavonoid contents were determined by the Folin-Ciocalteu method and AlCl3 colorimetry, respectively. It was found that the antioxidant capacities were diverse among different grape peels and seeds. Moreover, several phenolic compounds were identified and quantified, including gallic acid, cyanidin-3-glucoside, epicatechin, catechin gallate, ferulaic acid, rutin and resveratrol, which could contribute to the antioxidant capacities of these grape peels and seeds. Several grape wastes with strong antioxidant activity could be abundant sources of natural bioactive compounds, and have the potential for development into functional foods, food additives and pharmaceuticals.

Five-Golden-Flowers Tea: Green Extraction and Hepatoprotective Effect against Oxidative Damage.

The consumption of herbal teas has become popular in recent years due to their attractive flavors and outstanding antioxidant properties. The Five-Golden-Flowers tea is a herbal tea consisting of five famous edible flowers. The effects of microwave-assisted extraction parameters on the antioxidant activity of Five-Golden-Flowers tea were studied by single-factor experiments, and further investigated using response surface methodology. Under the optimal parameters (53.04 mL/g of solvent/material ratio, 65.52 °C, 30.89 min, and 500 W), the ferric-reducing antioxidant power, Trolox equivalent antioxidant capacity, and total phenolic content of the herbal tea were 862.90 ± 2.44 µmol Fe2+/g dry weight (DW), 474.37 ± 1.92 µmol Trolox/g DW, and 65.50 ± 1.26 mg gallic acid equivalent (GAE)/g DW, respectively. The in vivo antioxidant activity of the herbal tea was evaluated on alcohol-induced acute liver injury in mice. The herbal tea significantly decreased the levels of aspartate aminotransferase, total bilirubin, and malonaldehyde at different doses (200, 400, and 800 mg/kg); improved the levels of liver index, serum triacylglycerol, and catalase at dose of 800 mg/kg. These results indicated its role in alleviating hepatic oxidative injury. Besides, rutin, chlorogenic acid, epicatechin, gallic acid, and p-coumaric acid were identified and quantified by high performance liquid chromatography (HPLC), which could contribute to the antioxidant activity of the herbal tea.

[A Meta analysis of risk factors for asthma in Chinese children].

OBJECTIVE: To investigate the main risk factors for asthma in Chinese children, and to provide a reference for the prevention and treatment of asthma. METHODS: The databases including CNKI, Wanfang Data, China Biology Medicine disc, VIP Database for Chinese Technical Periodicals, Web of Science, and PubMed were searched for studies on risk factors for asthma in Chinese children published up to September 2017. Stata 12.0 was used for the Meta analysis. RESULTS: A total of 24 case-control studies were included, with 5 309 cases in the case group and 6 404 cases in the control group. The Meta analysis showed that a family history of asthma (OR=5.246, 95%CI: 3.435-8.011), a family history of allergy (OR=4.627, 95%CI: 2.450-8.738), atopic constitution (OR=4.659, 95%CI: 2.511-8.644), allergic rhinitis (OR=11.510, 95%CI: 6.769-19.574), a history of eczema/dermatitis (OR=4.919, 95%CI: 3.514-6.886), a history of allergies (OR=4.732, 95%CI: 2.802-7.989), a history of food allergies (OR=5.890, 95%CI: 3.412-10.166), a history of drug allergies (OR=4.664, 95%CI: 2.637-8.252), mold contamination at home (OR=2.483, 95%CI: 1.671-3.690), flowers at home (OR=1.748, 95%CI: 1.383-2.209), a history of house decoration (OR=2.823, 95%CI: 2.206-3.935), and cesarean section (OR=1.894, 95%CI: 1.166-3.077) were risk factors for asthma in children, while breastfeeding was a protective factor against asthma (OR=0.508, 95%CI: 0.396-0.653). CONCLUSIONS: The development of asthma in Chinese children is associated with a variety of factors, among which a family history of asthma, a family history of allergy, atopic constitution, a history of allergies, allergic comorbidities, cesarean section, and bad family environment can increase the risk of asthma in children, while breastfeeding can reduce the risk.

Protective effects of tea extracts against alcoholic fatty liver disease in mice via modulating cytochrome P450 2E1 expression and ameliorating oxidative damage.

The alcoholic fatty liver disease (AFLD) has been a severe public health problem. Oxidative stress is involved in the initiation and progression of AFLD. Tea is a popular beverage worldwide with strong antioxidant activity. In this research, our purpose is to explore and compare the effects of 12 selected teas on AFLD. The ethanol liquid diet was used to feed the mice, and 12 tea extracts were administrated at 200 mg/kg body weight every day for 4 weeks. The results showed that the application of several tea extracts exhibited different inhibitory effects on lipid accumulation induced by sub-acute alcohol consumption based on the determination of triglyceride concentration and the histological alteration in the liver. In addition, several teas significantly decreased serum alanine aminotransferase and aspartate aminotransferase activities, inhibited the cytochrome P450 2E1 expression, and promoted alcohol metabolism (p < .05). Besides, compared with the model group, several teas obviously elevated superoxide dismutase and glutathione peroxidase activities as well as glutathione content, and remarkably decreased malondialdehyde level (p < .05). In general, Fried Green Tea, Fenghuang Narcissus Oolong Tea, and Pu-erh Dark Tea possessed potential preventive effects on AFLD. Moreover, the main phytochemicals in the three tea extracts were determined and quantified via high-performance liquid chromatography, and the most commonly detected ingredients were catechins and caffeine, which could exert the protective effects on AFLD.

Hepatoprotective effects of Hovenia dulcis seeds against alcoholic liver injury and related mechanisms investigated via network pharmacology.

BACKGROUND: Alcoholic liver disease (ALD) is a worldwide health problem, and natural products have been shown to improve ALD due to their antioxidant activities. Some parts of Hovenia dulcis (H. dulcis), such as roots, peduncles, and stems, provide health benefits. Nevertheless, the effects and mechanisms of H. dulcis seeds on ALD have not yet been fully elucidated. AIM: To determine H. dulcis antioxidant activity, evaluate its effects against ALD, and investigate the related mechanisms via network pharmacology. METHODS: The antioxidant activity of H. dulcis seed was determined by both ferric-reducing antioxidant power and trolox equivalent antioxidant capacity assays. The total phenolic and flavonoid contents were determined by Folin-Ciocalteu method and aluminum chloride colorimetry, respectively, and polysaccharide was determined by phenol-sulfuric acid method. The effects of H. dulcis seeds against alcoholic liver injury were investigated in mice with water extract pretreatment for 7 days followed by alcohol administration. Moreover, the mechanisms of action were explored with network pharmacology. RESULTS: The results showed that H. dulcis seeds possessed strong antioxidant activity (245.11 ± 10.17 µmol Fe2+/g by ferric-reducing antioxidant power and 284.35 ± 23.57 µmol TE/g by trolox equivalent antioxidant capacity) and contained remarkable phenols and flavonoids, as well as a few polysaccharides. H. dulcis seeds attenuated alcohol-induced oxidative liver injury, showing reduced serum alanine and aspartate aminotransferases, alkaline phosphatase, and triglyceride, elevated hepatic glutathione, increased activities of superoxide dismutase and catalase, and reduced malondialdehyde and hepatic triglyceride. The results of network pharmacology analysis indicated that kaempferol, stigmasterol, and naringenin were the main bioactive compounds in H. dulcis seeds and that modulation of oxidative stress, inflammation, gut-derived products, and apoptosis were underlying mechanisms of the protective effects of H. dulcis seeds on ALD. CONCLUSION: The results of this study demonstrate that H. dulcis seeds could be a good natural antioxidant source with protective effects on oxidative diseases such as ALD.

The In Vivo Antioxidant and Hepatoprotective Actions of Selected Chinese Teas.

Tea is a popular beverage and shows very strong in vitro antioxidant activity. However, the relationship among in vitro and in vivo antioxidant activities in teas is seldom reported. In this study, in vivo antioxidant and hepatoprotective activities of 32 selected Chinese teas were evaluated on a mouse model with acute alcohol-induced liver injury. The results showed that most teas significantly reduced the levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, triacylglycerol, and total bilirubin in the sera of mice at a dose of 400 mg/kg. In addition, most teas greatly decreased the malondialdehyde level and increased the levels of superoxide dismutase, glutathione peroxidase, and glutathione in the liver of mice, indicating the antioxidant and hepatoprotective activities of teas. Furthermore, the in vivo antioxidant activity of dark tea was stronger than that of green tea, opposite to the results of the in vitro study. Among these 32 teas, Black Fu Brick Tea, Pu-erh Tea, and Qing Brick Tea showed the strongest antioxidant and hepatoprotective activities. Moreover, total phenolic content as well as the contents of epicatechin, gallocatechin gallate, and chlorogenic acid were found to contribute, at least partially, to the antioxidant and hepatoprotective actions of these teas. Overall, teas are good dietary components with antioxidant and hepatoprotective actions.

Bioactive Compounds and Bioactivities of Ginger (Zingiber officinale Roscoe).

Ginger (Zingiber officinale Roscoe) is a common and widely used spice. It is rich in various chemical constituents, including phenolic compounds, terpenes, polysaccharides, lipids, organic acids, and raw fibers. The health benefits of ginger are mainly attributed to its phenolic compounds, such as gingerols and shogaols. Accumulated investigations have demonstrated that ginger possesses multiple biological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, neuroprotective, cardiovascular protective, respiratory protective, antiobesity, antidiabetic, antinausea, and antiemetic activities. In this review, we summarize current knowledge about the bioactive compounds and bioactivities of ginger, and the mechanisms of action are also discussed. We hope that this updated review paper will attract more attention to ginger and its further applications, including its potential to be developed into functional foods or nutraceuticals for the prevention and management of chronic diseases.

Polyphenolic Profile and Antioxidant Capacity of Extracts from Gordonia axillaris Fruits.

An ultrasonic-assisted extraction (UAE) method was adopted to extract natural antioxidants from edible Gordonia axillaris fruit. Single-factor experiments and response surface methodology were conducted to investigate the influences of five different parameters on antioxidant capacity. The optimal conditions of the UAE were 39.78% ethanol, 30.94 mL/g solvent/material ratio, 59.47 min extraction time, 40 °C temperature, and 400 W ultrasonication power. The antioxidant capacity was 525.05 ± 14.34 µmol Trolox/g DW under the optimal conditions, which was in agreement with the predicted one (531.71 µmol Trolox/g DW). Additionally, in comparison with two traditional methods (maceration and Soxhlet extraction), the established UAE method greatly improved the yield of antioxidants and significantly reduced the extraction time. Besides, nine phenolic compounds were identified and quantified in the extract of Gordonia axillaris fruits by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), including rutin, gallic acid, protocatechuic acid, epicatechin, 2-hydrocinnamic acid, p-coumaric acid, quercetin, epicatechin gallate, and ferulic acid. The richness of phenolic compounds in the Gordonia axillaris fruits indicated its potential health benefits, and its extract rich in antioxidants could be developed into functional food or nutraceuticals with the potential to prevent certain diseases induced by oxidative stress, such as cardiovascular diseases and cancers. This study also provided a way to enhance the economic values of Gordonia axillaris fruits compared to raw fruits.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.).

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.

Phenolic Profiles and Antioxidant Activities of 30 Tea Infusions from Green, Black, Oolong, White, Yellow and Dark Teas.

Tea is among the most consumed drink worldwide, and its strong antioxidant activity is considered as the main contributor to several health benefits, such as cardiovascular protection and anticancer effect. In this study, the antioxidant activities of 30 tea infusions, which were obtained by the mimic of drinking tea of the public, from green, black, oolong, white, yellow and dark teas, were evaluated using ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, ranging from 504.80 ± 17.44 to 4647.47 ± 57.87 µmol Fe2+/g dry weight (DW) and 166.29 ± 24.48 to 2532.41 ± 50.18 µmol Trolox/g DW, respectively. Moreover, their total phenolic contents (TPC) were detected by Folin-Ciocalteu assay and were in the range of 24.77 ± 2.02 to 252.65 ± 4.74 mg gallic acid equivalent (GAE)/g DW. Generally, Dianqing Tea, Lushan Yunwu Tea, and Xihu Longjing Tea showed the strongest antioxidant activities among 30 teas. Furthermore, the phenolic compounds in tea infusions were identified and quantified, with catechins most commonly detected, especially in green tea infusions, which were main contributors to their antioxidant activities. Besides tea polyphenols, considerable content of caffeine also presented in 30 tea infusions.

Phytochemical Composition and Antioxidant Capacity of 30 Chinese Teas.

Tea has been reported to prevent and manage many chronic diseases, such as cancer, diabetes, obesity, and cardiovascular diseases, and the antioxidant capacity of tea may be responsible for these health benefits. In this study, the antioxidant capacities of fat-soluble, water-soluble, and bound-insoluble fractions of 30 Chinese teas belonging to six categories, namely green, black, oolong, dark, white, and yellow teas, were systematically evaluated, applying ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays. In addition, total phenolic contents of teas were determined by Folin-Ciocalteu method, and the contents of 18 main phytochemical compounds in teas were measured by high-performance liquid chromatography (HPLC). The results found that several teas possessed very strong antioxidant capacity, and caffeine, theaflavine, gallic acid, chlorogenic acid, ellagic acid, and kaempferol-3-O-glucoside, as well as eight catechins, were the main antioxidant compounds in them. Thus, these teas could be good natural sources of dietary antioxidants, and their extracts might be developed as food additives, nutraceuticals, cosmetics, and pharmaceuticals.

Effects and Mechanisms of Tea and Its Bioactive Compounds for the Prevention and Treatment of Cardiovascular Diseases: An Updated Review.

Cardiovascular diseases (CVDs) are critical global public health issues with high morbidity and mortality. Epidemiological studies have revealed that regular tea drinking is inversely associated with the risk of CVDs. Additionally, substantial in vitro and in vivo experimental studies have shown that tea and its bioactive compounds are effective in protecting against CVDs. The relevant mechanisms include reducing blood lipid, alleviating ischemia/reperfusion injury, inhibiting oxidative stress, enhancing endothelial function, attenuating inflammation, and protecting cardiomyocyte function. Moreover, some clinical trials also proved the protective role of tea against CVDs. In order to provide a better understanding of the relationship between tea and CVDs, this review summarizes the effects of tea and its bioactive compounds against CVDs and discusses potential mechanisms of action based on evidence from epidemiological, experimental, and clinical studies.

Effects and Mechanisms of Tea for the Prevention and Management of Diabetes Mellitus and Diabetic Complications: An Updated Review.

Diabetes mellitus has become a serious and growing public health concern. It has high morbidity and mortality because of its complications, such as diabetic nephropathy, diabetic cardiovascular complication, diabetic neuropathy, diabetic retinopathy, and diabetic hepatopathy. Epidemiological studies revealed that the consumption of tea was inversely associated with the risk of diabetes mellitus and its complications. Experimental studies demonstrated that tea had protective effects against diabetes mellitus and its complications via several possible mechanisms, including enhancing insulin action, ameliorating insulin resistance, activating insulin signaling pathway, protecting islet ß-cells, scavenging free radicals, and decreasing inflammation. Moreover, clinical trials also confirmed that tea intervention is effective in patients with diabetes mellitus and its complications. Therefore, in order to highlight the importance of tea in the prevention and management of diabetes mellitus and its complications, this article summarizes and discusses the effects of tea against diabetes mellitus and its complications based on the findings from epidemiological, experimental, and clinical studies, with the special attention paid to the mechanisms of action.

Effects of Tannase and Ultrasound Treatment on the Bioactive Compounds and Antioxidant Activity of Green Tea Extract.

The present study investigated the effects of tannase and ultrasound treatment on the bioactive compounds and antioxidant activity of green tea extract. The single-factor experiments and the response surface methodology were conducted to study the effects of parameters on antioxidant activity of green tea extract. The highest antioxidant activity was found under the optimal condition with the buffer solution pH value of 4.62, ultrasonic temperature of 44.12 °C, ultrasonic time of 12.17 min, tannase concentration of 1 mg/mL, and ultrasonic power of 360 W. Furthermore, phenolic profiles of the extracts were identified and quantified by high-performance liquid chromatography. Overall, it was found that tannase led to an increase in gallic acid and a decrease in epigallocatechin gallate, and ultrasounds could also enhance the efficiency of enzymatic reaction.

[Effects of irrigation quota on moisture and salt redistribution in apple orchard soil in arid region].

Taking the salinized apple orchard soil in Qin'an County of Gansu Province, Northwest China as test object, a field experiment was conducted to study the effects of different irrigation quota (0, 900, 1800, 2700, and 3600 m3 x hm(-2)) on the redistribution of moisture and salt in 0-100 cm soil profile on the 10, 20, and 30 d during apple florescence stage. With the increase of irrigation quota, the leached depth of Na+ increased and its hysteretic effect of redistribution was more obvious, "the zero flux plane" of Ca2+ disappeared gradually, the scope of "the zero flux plane" of Mg2+ increased gradually, the leaching-migration mode of Cl- changed from "fluctuation" to "straight-line" and the evaporation-migration changed from "fluctuation" to "ladder", the redistribution pattern of SO4(2-) showed "point", and the position of redistribution and accumulation of HCO3- shifted gradually from the bottom to upper layer in soil profile. In the middle of the soil profile with deeper groundwater table, there existed a "zero flux plane" of salt, which shifted gradually from the upper layer to the bottom during the redistribution of moisture in soil profile, embodying the characteristics of moisture depletion in upland soils. When the irrigation quota was between 2700 and 3600 m3 x hm(-2), irrigation was helpful to the leaching of salt and water-soluble Na+ in the 0-100 cm soil profile. However, when the irrigation quota was < 1800 m3 x hm(-2), irrigation accelerated the salt accumulation in surface soil. Therefore, from the viewpoints of salt leaching and water-saving, an irrigation quota of 1800-2700 m3 x hm(-2) in spring would be more appropriate for the salinized apple orchard soil in arid regions.

[Effects of long-term fertilization on water-stable aggregates in calcic kastanozem of Loess Plateau].

The study on the size distribution of water-stable aggregates (WSAs) in calcic kastanozem of Loess Plateau after 27 years fertilization showed that compared with those of natural soil, the contents of > 0.25 mm WSAs in 0-10 cm and 10-20 cm layers of cultivated soil decreased by 21.35% and 38.82%, respectively, and those of > or = 0.5 mm WSAs also had a decreasing trend, with the greatest decrement of > 5 mm and 5-2 mm WSAs. On the contrary, the contents of 0.5-0.25 mm WSAs in the two soil layers increased by 104.75% and 23.13%, respectively. All sizes WSAs had higher contents in 0-10 cm than in 10-20 cm soil layer. Fertilization had remarkable effects on the formation of WSAs. Under the applications of organic manure and its combination with chemical fertilizers, the content of 5-2 mm WSAs increased most, followed by that of > 5 mm WSAs. After applying organic manure, organic manure plus chemical fertilizers, and straws, the contents of larger sizes WSAs increased significantly, being beneficial to the improvement of soil structure. In all fertilization treatments, the mean mass diameter (MMD) of WSAs was larger in 0-10 cm than in 10-20 cm soil layer. Compared with non-fertilization, long-term fertilization increased the MMD of WSAs, and organic manure was superior to chemical fertilizers. The MMD of WSAs was positively correlated with the amount of > 0.25 mm WSAs.