Alternativas fitoterápicas no controle da obesidade / Phytotherapy alternatives in obesity control / Alternativas herbales en el control de la obesidad

Nos últimos anos, a obesidade vem aumentando consideravelmente entre adultos e crianças e, segundo a OMS, estima-se que em 2025 o número de obesos ultrapasse a 2,3 milhões em todo o mundo. O indivíduo obeso apresenta maiores riscos de desenvolver doenças crônicas não transmissíveis, como diabetes, doenças cardiovasculares, dislipidemias e ainda alguns tipos de cânceres. O tratamento para a obesidade é variado e inclui mudanças no estilo de vida como: hábitos alimentares e prática de atividade física, tratamento medicamentoso, cirurgia bariátrica e fitoterápicos com o potencial de auxiliar no tratamento. O objetivo deste trabalho foi realizar uma revisão bibliográfica a fim de avaliar os benefícios da utilização de medicamentos fitoterápicos como auxiliar no tratamento da obesidade, seus principais ativos, mecanismos de ação e sua utilização popular. Dentre as plantas pesquisadas e que demonstraram potencial para atuar no tratamento da obesidade encontram-se Camelia sinensis, Citrus aurantium, Hibiscus sabdariffa, Coffea arabica, Ephedra sinica, Zingiber oficinale e Senna alexandrina. Os principais mecanismos de ação envolvidos no potencial anti-obesidade das plantas medicinais são a capacidade de controle do apetite e ingestão de energia, estímulo da termogênese, inibição da lipase pancreática e redução da absorção de gordura, diminuição da lipogênese e aumento da lipólise. Desta forma, conclui-se que as plantas selecionadas neste estudo apresentaram efeitos positivos nos parâmetros bioquímicos e físicos, podendo ser incluídas nos protocolos como coadjuvantes nos tratamentos de emagrecimento.

In recent years, obesity has increased considerably among adults and children and according to the WHO, it is estimated that in 2025 the number of obese people will exceed 2.3 million worldwide. The obese individual is at greater risk of developing non-communicable chronic diseases, such as diabetes, cardiovascular disease, dyslipidemia and even some types of cancer. The treatment for obesity is varied, including changes in lifestyle such as eating habits and physical activity, drug treatment, bariatric surgery and phytotherapy with the potential to aid in the treatment. The objective of this work was to carry out a literature review, evaluating the benefits of using herbal medicines as an aid in the treatment of obesity, their main assets, mechanisms of action and their popular use. Among the plants researched and that have shown potential to act in the treatment of obesity are Camelia sinensis, Citrus aurantium, Hibiscus sabdariffa, Coffea arabica, Ephedra sinica, Zingiber officiale and Senna alexandrina. The main mechanisms of action involved in the antiobesity potential of medicinal plants are the ability to control appetite and energy intake, thermogenesis stimulation, pancreatic lipase inhibition and reduction of fat absorption, lipogenesis decrease and lipolysis increase. Thus, it is concluded that the plants selected in this study showed positive effects on biochemical and physical parameters, and can be included in the protocols as adjuvants in weight loss treatments.

En los últimos años, la obesidad ha aumentado considerablemente entre adultos y niños y, según la OMS, se estima que en 2025 el número de obesos superará los 2,3 millones en todo el mundo. Los individuos obesos tienen un mayor riesgo de desarrollar enfermedades crónicas no transmisibles, como la diabetes, las enfermedades cardiovasculares, las dislipidemias e incluso algunos tipos de cáncer. El tratamiento de la obesidad es variado e incluye cambios en el estilo de vida como: hábitos alimenticios y práctica de actividad física, tratamiento farmacológico, cirugía bariátrica y medicamentos a base de hierbas con potencial para ayudar en el tratamiento. El objetivo de este trabajo fue realizar una revisión bibliográfica para evaluar los beneficios del uso de las hierbas medicinales como ayuda en el tratamiento de la obesidad, sus principales activos, mecanismos de acción y su uso popular. Entre las plantas investigadas y que mostraron potencial para actuar en el tratamiento de la obesidad están Camelia sinensis, Citrus aurantium, Hibiscus sabdariffa, Coffea arabica, Ephedra sinica, Zingiber oficinale y Senna alexandrina. Los principales mecanismos de acción implicados en el potencial antiobesidad de las plantas medicinales son la capacidad de controlar el apetito y la ingesta de energía, estimular la termogénesis, inhibir la lipasa pancreática y reducir la absorción de grasas, disminuir la lipogénesis y aumentar la lipólisis. Por lo tanto, se concluye que las plantas seleccionadas en este estudio mostraron efectos positivos sobre los parámetros bioquímicos y físicos, y pueden ser incluidas en los protocolos como coadyuvantes en los tratamientos de pérdida de peso.

Exogenous melatonin improves tea quality under moderate high temperatures by increasing epigallocatechin-3-gallate and theanine biosynthesis in Camellia sinensis L.

Global warming has multifarious effects on crop growth and productivity. Nonetheless, the effects of moderate-high temperatures and melatonin on tea yield and quality remain unclear. In this study, we found that melatonin, a universal growth stimulatory molecule, not only promotes photosynthesis and biomass accumulation in tea plants (Camellia sinensis L.) but also improves tea quality under sub high temperature (SHT). SHT increased the dry biomass and photosynthesis by 40.8% and 28.1%, respectively, and exogenous melatonin caused a further improvement. Moreover, SHT increased the total polyphenol concentrations and decreased the free amino acid concentrations, leading to a significant increase (68.2%) in polyphenol to free amino acid ratio. However, melatonin decreased the polyphenol to free amino acid ratio by delicately improving the concentrations of polyphenols and amino acids. Consistent with the total polyphenol, melatonin increased the concentrations of (-)-catechin, (-)-gallocatechin (GC), and (-)-epigallocatechin-3-gallate (EGCG) in tea leaves. The qRT-PCR analysis revealed that melatonin increased the transcript levels of catechins biosynthesis genes, such as CsCHS, CsCH1, CsF3H, CsDFR, CsANS, CsLAR, and CsANR under SHT. Meanwhile, the theanine concentration was decreased by SHT, which was attributed to the attenuated expression of CsGS, CsGOGAT, CsGDH, and CsTS1. Nonetheless, melatonin significantly increased those transcripts and the content of theanine under SHT. Melatonin also increased the caffeine content by inducing the expression of CsTIDH, CssAMS, and CsTCS1. These results suggest that melatonin could positively alter tea growth and quality by modulating the photosynthesis and biosynthesis of polyphenols, amino acids, and caffeine in tea leaves under SHT.

Stimulation in primary and secondary metabolism by elevated carbon dioxide alters green tea quality in Camellia sinensis L.

Rising CO2 concentration, a driving force of climate change, is impacting global food security by affecting plant physiology. Nevertheless, the effects of elevated CO2 on primary and secondary metabolism in tea plants (Camellia sinensis L.) still remain largely unknown. Here we showed that exposure of tea plants to elevated CO2 (800 µmol mol-1 for 24 d) remarkably improved both photosynthesis and respiration in tea leaves. Furthermore, elevated CO2 increased the concentrations of soluble sugar, starch and total carbon, but decreased the total nitrogen concentration, resulting in an increased carbon to nitrogen ratio in tea leaves. Among the tea quality parameters, tea polyphenol, free amino acid and theanine concentrations increased, while the caffeine concentration decreased after CO2 enrichment. The concentrations of individual catechins were altered differentially resulting in an increased total catechins concentration under elevated CO2 condition. Real-time qPCR analysis revealed that the expression levels of catechins and theanine biosynthetic genes were up-regulated, while that of caffeine synthetic genes were down-regulated in tea leaves when grown under elevated CO2 condition. These results unveiled profound effects of CO2 enrichment on photosynthesis and respiration in tea plants, which eventually modulated the biosynthesis of key secondary metabolites towards production of a quality green tea.

Neurobehavioral changes in mice offspring exposed to green tea during fetal and early postnatal development.

BACKGROUND: Green tea extract (GTE) has various health promoting effects on animals and humans. However, the effects of perinatal exposure to GTE on the behavioral aspects of offspring have not been elucidated thus far. GTE was provided for pregnant female mice at concentrations of either 20 or 50 g/L, beginning the day of conception until the third week after delivery, postnatal day 22 (PD 22). Mice pups were subjected to behavioral testing to assess sensory motor reflexes, locomotion, anxiety, and learning on various postnatal days. RESULTS: Perinatal exposure to GTE resulted in a significant reduction in body weight, as well as earlier body hair appearance and opening of the eyes. Sensory motor reflexes exhibited faster responses and significant stimulatory effects in pups exposed to GTE. During the adolescent period, male and female offspring exhibited increased locomotor activity (on PD 22), reduced anxiety and fear (on PD 25), and enhanced memory and learning abilities (on PD 30), all in both GTE treated groups. All blood counts (RBCs, WBCs, Hb, and platelets), and glucose, cholesterol, triglyceride, and low density lipoprotein concentrations were significantly lower in the GTE-treated pups; however, there was no effect on high density lipoprotein levels. CONCLUSION: Our data provide evidence that the high dose of GTE (50 g/L) had higher anxiolytic properties and positive effects on locomotor activities and sensory motor reflexes, as well as learning and memory of the offspring than the low dose of GTE (20 g/L).

Intervenções nutricionais na promoção da perda de peso: faseolamina - revisão sistemática com metanálise e alimentos com possíveis benefícios - revisão sistemática para construção de tecnologia educacional / Nutritional interventions in weight loss promotion: phaseolamine - systematic review with meta-analysis and foods with possible benefits - systematic review for building educational technology

A obesidade é uma doença crônica não transmissível e considerada epidemia mundial com prevalência alarmante. Está associada à morbimortalidade e é fator de risco para doença cardiovascular (DCV), diabetes mellitus tipo 2 (DM2), hipertensão arterial sistêmica(HAS), dislipidemias, osteoartrite e alguns tipos de câncer. As Diretrizes Brasileiras de Obesidade 2009/2010 da Associação Brasileira para o Estudo da Obesidade e da Síndrome Metabólica referem ser pequeno o número de estudos que comprovem os efeitos termogênicos, anorexígenos ou redutores de peso de suplementos nutricionais de cafeína e capsaicina e mencionam poucos alimentos. No entanto a mídia cita rotineiramente vários alimentos como tratamento consolidado para perda de peso, sem que existam evidências científicas que suportem esta indicação. Com o objetivo de elaborar uma tecnologia educacional para indivíduos obesos de um hospital universitário, com esclarecimento sobre intervenções nutricionais efetivas para promoção da perda de peso foram conduzidas duas revisões sistemáticas. A busca de referências foi feita nas Bases eletrônicas ­ Pubmed, Cochrane Central de Ensaios Clínicos, Cinhal e Lilacs. Uma das revisões incluiu metanálise de ensaios clínicos randomizados sobre a utilização da faseolamina na promoção de perda ponderal e redução de massa gorda. A outra revisão incluiu apenas revisões sistemáticas com metanálise avaliando a efetividade de alimentos ou substâncias extraídas destes na promoção da perda de peso. Na metanálise foram incluídos 5 ensaios clínicos. A perda ponderal foi maior e estatisticamente significativa com a utilização da faseolamina -1,70Kg (IC de -2,44 a -0,97) e também a redução de massa gorda foi superior e estatisticamente significativa nos pacientes tratados com faseolamina -1,85Kg (IC de -2,49 a -1,21). Na outra revisão sistemática foram incluídos 7 artigos ,4 sobre chá verde ( na forma de infusão ou como suplemento), 2 sobre pimenta vermelha ( nos alimentos ou como suplemento) e 1 sobre peixes fonte de ômega 3 ou suplemento de ômega 3. De acordo com o resultado da metanálise, o uso da faseolamina promove perda ponderal e de massa gorda em pacientes obesos e com sobrepeso. A utilização da faseolamina é alternativa auxiliar no tratamento da obesidade. Considerando a revisão sistemática, a utilização de peixes fonte de ômega 3 pode auxiliar a perda de peso, assim como o consumo de pimenta vermelha em dosagem de pelo menos 2mg/dia de capsaicina antes das refeições. O consumo de chá verde não promoveu perda de peso clinicamente relevante. O presente estudo levou a elaboração de uma tecnologia educacional descrita como uma cartilha, para ser utilizada na educação em saúde da população obesa, com orientações no tratamento da obesidade e foi intitulada "Perda de Peso: Alimentos e Fitoterápicos que realmente podem ajudar você"

Obesity is a chronic nontransmissible disease that is considered a worldwide epidemic with alarming prevalence. It is associated with morbidity and mortality and is a risk factor for cardiovascular disease (CVD), diabetes mellitus type 2 (DM2), systemic hypertension (SHT), dyslipidemias, osteoarthritis and some types of cancer. Brazilian Obesity Guidelines 2009/2010 of the Brazilian Association for the Study of Obesity and Metabolic Syndrome report that there is a scarcity of studies that confirm the thermogenic, anorexigenic and weight reducing effects of nutritional supplements of caffeine and capsaicin and mention few food items. However, the media routinely cites a number of foods as treatment for weight loss, with no scientific evidence to support these allegations. Two systematic reviews were conducted to create an educational technology for obese individuals from a university hospital, with information about effective nutritional interventions that promote weight loss. The search for references was carried out in the following electronic databases: Pubmed, Cochrane Central Register of Controlled Trials, Cinhal and Lilacs. One of the reviews included meta-analysis of randomized clinical trials on the use of phaseolamin to promote weight loss and a reduction in fat mass. The other review involved only systematic reviews with meta-analysis, assessing the effectiveness of foods or substances extracted from them in the promotion of weight loss. Meta-analysis included 5 clinical trials. Weight loss was greater and statistically significant with the use of phaseolamin -1.70Kg (CI between -2.44 and -0.97) and the reduction in fat mass was higher and statistically significant in patients treated with phaseolamin -1.85Kg (CI between -2.49 and -1.21). The other systematic review involved 7 articles, 4 on green tea (in the form of infusion or a supplement), 2 on red pepper (in food or as supplement) and 1 on omega-rich fish or omega 3 supplement. According to the results of meta-analysis, the use of phaseolamin promotes weight and fat mass loss in obese and overweight patients. The use of phaseolamin is an auxiliary alternative in the treatment of obesity. The systematic review revealed that the use of omega 3-rich fish can contribute to weight loss, as well as consuming red pepper in a dose of at least 2mg/dia of capsaicin before meals. Green tea intake did not promote clinically relevant weight loss. The present study led to the creation of an educational technology in the form of a booklet, to be used in health education for obese individuals, with orientation regarding the treatment of obesity, and entitled "Weight Loss: Foods and Phytotherapics that can really help you"

Histochemical evaluation of catechins in PEG stressed transgenic tea plants using catechin-specific-diazotized sulfanilamide reagent.

We investigated the applicability of catechin-specific-reagent (CSR) for histochemical evaluation of catechins. The diazotized arylamine moiety in CSR reacts specifically with the A-ring of catechins to yield a golden yellow complex. This makes it highly specific for spectrophotometric quantification of catechins. Therefore, microtome cut sections of untransformed and osmotin-expressing transgenic leaves and stem of tea were stained with CSR. We found catechins in the form of golden yellow globules. The catechin globules increased in the structurally intact and highly turgid cells of osmotin expressing transgenic tea plants after stress treatment with 20% PEG; by contrast, the cells in non-transgenic plants accumulated fewer catechin globules. Spectrophotometric quantification of catechins also confirmed higher levels in transgenics compared to untransformed plants. We found elevated accumulation of catechins in stress tolerant cells of tea leaves.

Changes of growth, photosynthesis and alteration of leaf antioxidative defence system of tea [Camellia sinensis (L.) O. Kuntze] seedlings under aluminum stress.

Tea [Camellia sinensis (L.) O. Kuntze] is an aluminum (Al) hyperaccumulator plant and is commercially important due to its high content of antioxidants. Although Al induced growth is well-known for the plants growing in acid soil, yet the cause underlying the stimulatory effect of Al has not been fully understood. To investigate the possible role of Al in growth induction, we studied morphological, physiological as well as biochemical changes of tea plant under different Al concentrations (0-4,000 µM). In hydroponics, Al (15 µM), enhanced shoot and root growth, but at higher concentrations, it caused oxidative damage which culminated in a cascade of biochemical changes, Al content increased concurrently with the maturity of the leaf as well as stem tissues than their younger counterparts. Hematoxylin staining indicated that Al accumulation started after 6 h of exposure in the tips of young roots and accumulation was dose dependent. The physiological parameters such as pigments, photosynthetic rate, transpiration and stomatal conductance were declined due to Al toxicity. Alteration in activated oxygen metabolism was also evidenced by increasing lipid peroxidation, membrane injury, evolution of superoxide anions and accumulation of H(2)O(2). Contents of phenols initially exhibited an acceleration which gradually plummeted at higher levels whereas total sugar and starch contents decimated beyond 15 µM of Al concentration. Activities of antioxidant defense enzymes were increased with the elevated concentration of Al. Expression of citrate synthase gene was up-regulated in the mature leaves, young as well as old roots simultaneously with increased concentration of Al in those parts; indicating the formation of Al-citrate complex. These results cooperatively specified that Al concentration at lower level promoted growth but turned out to be a stressor at elevated stages indicating the sensitivity of the cultivar (T-78) to Al.

Alpha-tubulin (CsTUA) up-regulated during winter dormancy is a low temperature inducible gene in tea [Camellia sinensis (L.) O. Kuntze].

The present manuscript describes cloning and expression characterization of alpha-tubulin (CsTUA) gene in an evergreen tree tea [Camellia sinensis (L.) O. Kuntze] in response to winter dormancy (WD), abiotic stresses (sodium chloride, polyethylene glycol, and hydrogen peroxide) and plant growth regulators [abscisic acid (ABA), gibberellic acid (GA(3)), indole-3-butyric acid (IBA), and 6-benzylaminopurine (BA)]. CsTUA encoded a putative protein of 449 amino acids with a calculated molecular weight of 49.6 kDa and an isoelectric point (pI) of 5.09. CsTUA shared 76-84 and 90-95% identity at nucleotide and amino acid level, respectively with TUA genes from other plant species. During the period of active growth (PAG), CsTUA showed maximum expression in floral buds as compared to leaf, stem, fruit and root. Though the transcript was not detectable in the younger leaf tissue during the PAG, the expression was induced within 24 h of the low temperature (LT) treatment. The expression was not modulated by the plant growth regulators either in the tissue harvested during PAG or during WD. It was interesting to record that the expression of CsTUA was up-regulated in response to sodium chloride, polyethylene glycol, and hydrogen peroxide. Data has been discussed on the possible role of CsTUA in imparting tolerance to stresses including to LT so that the tea does not exhibit deciduous nature during winters.

Antagonism of phenanthrene cytotoxicity for human embryo lung fibroblast cell line HFL-I by green tea polyphenols.

Polycyclic aromatic hydrocarbons (PAHs) have been detected in some commercial teas around the world and pose a threat to tea consumers. However, green tea polyphenols (GTP) possess remarkable antioxidant and anticancer effects. In this study, the potential of GTP to block the toxicity of the model PAH phenanthrene was examined in human embryo lung fibroblast cell line HFL-I. Both GTP and phenanthrene treatment individually caused dose-dependent inhibition of cell growth. A full factorial design experiment demonstrated that the interaction of phenanthrene and GTP significantly reduced growth inhibition. Using the median effect method showed that phenanthrene and GTP were antagonistic when the inhibitory levels were less than about 50%. Apoptosis and cell cycle detection suggested that only phenanthrene affected cell cycle significantly and caused cell death; GTP lowered the mortality of HFL-I cells exposed to phenanthrene; However, GTP did not affect modulation of the cell cycle by phenanthrene.

Phenylalanine ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H) and catechins (flavan-3-ols) accumulation in tea.

Phenylalanine ammonia-lyase and cinnamate 4-hydroxylase are important enzymes in allocating significant amounts of carbon from phenylalanine into the biosynthesis of several important secondary metabolites. Tea is an important crop of commerce known for its beverage and medicinally important flavonoid compounds, mainly catechins. As metabolic flux for the operation of the flavonoid pathway is maintained through the activities of PAL and C4H, thus, catechins biosynthesis in tea is critically dependent on the products of these enzymes. We examined the expression of PAL and C4H. Sequence encoding CsPAL was isolated from tea by polymerase chain reaction using sequence information available at the NCBI GenBank. Sequence encoding C4H was isolated from tea by using differential display of mRNA and rapid amplification of cDNA ends technology. CsC4H (AY641731) comprised of 1,352 bp full-length cDNA with open reading frame of 1,173 bp encoding 390 amino acids. Catechin contents decreased in response to drought stress (DS), abscisic acid (ABA), and gibberellic acid (GA(3)) treatments but increased in response to wounding. The expression of CsPAL and CsC4H showed the same behavior under the above treatments and was also in accordance with the catechin contents. A positive correlation between catechin contents and gene expression suggested a critical role of the enzymes in catechins biosynthesis and a crosstalk between phenylpropanoid and flavonoid pathways.

Treatment of acne vulgaris with 2% topical tea lotion.

OBJECTIVE: To use 2% tea lotion as natural plant remedy in the treatment of acne vulgaris. METHODS: We conducted this study in the Department of Dermatology and Venereology in Baghdad Teaching Hospital, Iraq during the period between October 2002 and October 2004. In this single blind randomly controlled therapeutic study, we enrolled 60 patients, their ages ranged from 14-22 years. There were 35 females and 25 males. We divided the patients equally into 2 groups; we instructed group A to use freshly prepared 2% tea lotion twice daily for 2 months, while group B used a control solution. We graded the acne vulgaris as mild and moderate acne by counting the number of papules and pustules. We carried out statistical analysis by computer using t-test, f-test, and chi-square when needed. RESULTS: Forty-nine patients completed the study. In group A (25 patients), we noted a significantly reduced mean lesion count of papules and pustules after 2 months of therapy. The response of patients to treatment was good in 64%, moderate in 24% and no response in 12%. The satisfaction of patients with treatment was full in 64%, partial in 24%, and no satisfaction in 12%. In group B (24 patients), the lesions showed no significant reduction after 2 months and the response of patients to treatment was good in 20.8%, moderate in 45.8%, and no response in 33.4%. The satisfaction of patients with treatment in this group was full in 4.2%, partial in 12.5%, and no satisfaction in 83.3%. The mean difference in outcome after 8 weeks between the 2 study groups was statistically significant. CONCLUSION: The 2% tea lotion has proved its efficacy as a topical therapy for acne vulgaris. This is a new natural plant extract, which lacks any side effects.

[Efficacy of emulsifiable formulations of two entomopathogenic fungi against small green leafhoppers on tea plant].

A field trial was conducted to test the efficacy of emulsifiable formulations of Beauveria bassiana (Bb) and Paecilomyces fumosoroseus (Pf) conidia in controlling small green leafhoppers (Empoasca spp.) on tea plant in a hillside tea garden located in Shuichang, Zhejiang during mid-summer 2002. Both Bb and Pf formulations contained 10(10) conidia x ml(-1). Adding 3% of imidacloprid 10% WP to each fungal formulation (W/V) resulted in two other formulations, i.e., Bb-imidacloprid mixture (BbIM) and Pf-imidacloprid mixture (PfIM). Besides the four formulations, a mineral oil-based liquid used to formulate the fungal conidia and containing 3% of imidacloprid 10% WP (OBLI) was also tested, and water spray was used as control (CK). Each of the treatments included three 60-m2 plots (replicates), which were sprayed twice with a 500-fold aqueous dilution of the corresponding formulation or preparation at a 12-d interval. Based on the leafhopper densities estimated by sampling in all plots at 3- or 4-d intervals after the first spray, the spray of BbIM or PfIM could better control the leafhoppers than the spray of Bb or Pf formulation. The maximal efficacy relative to CK reached 83.4% and 71.3% in the BbIM and PfIM treatments, respectively. Estimates of field efficacy obtained during the 25-d period after the first spray was 66.8% for BbIM, 62.1% for PfIM, 50.3% for OBLI, 49.5% for Bb, and 19.0% for Pf, respectively. A discussion was also given on the effect of local weather pattern and leafhopper population age structure on the results of the field trial, and on the application techniques to enhance the efficacy of mycoinsecticides against Empoasca species on tea plant.

Biochemical responses of Camellia sinensis (L.) O. Kuntze to heavy metal stress.

Three heavy metals-mercury (II), copper (II) and nickel (II), each at a concentration of 10 and 100 micrograms/ml, were tested for their effects on various biochemical constituents of tea leaves. Both NI (II) and Hg (II) decreased the phenolic contents, while Cu (II) increased it to some extent. The metal treatments enhanced the activity of phenyl alanine ammonia lyase (PAL), while the activity of poly phenol oxidase (PPO) showed a decline. Heavy metal stress also decreased the chlorophyll content of the leaves, along with a significant reduction in Hill activity. Proline content increased significantly in all treatments.

Evaluation of the antioxidative activity of tea by an oxygen electrode method.

The antioxidative activity was studied for 25 kinds of tea and catechins by a new evaluation method using an oxygen electrode. The concentration of catechins in 6 types of green tea was analyzed by HPLC. The result indicates that the antioxidative activity of green tea depends to some extent on the amount of catechins present.

Teas and Brews

In the Caribbean, part of our cultural heritage is 'tea'-drinking. It is generally accepted that a hot cup of 'tea' is needed in the morning to 'break the gas'. Likewise, afternoon tea, through less popular today, was an important part of the social culture of many people.

Chalcone synthase from Camellia sinensis: isolation of the cDNAs and the organ-specific and sugar-responsive expression of the genes.

Three full-length cDNAs (CHS1, CHS2 and CHS3) encoding chalcone synthase (CHS; EC 2.3.1.74) were isolated from young leaves of Camellia sinensis. Each cDNA encoded 389 amino acid residues, which showed 93-96% identity to one another. Oligonucleotides were synthesized on the basis of the 5'-untranslated sequences of the cDNAs and their corresponding transcripts could be distinguished. The CHS1, CHS2 and CHS3 transcripts were abundant in the leaves and stems. After an initial treatment with water in darkness, the transcripts fell to very low levels in the young leaves. These levels were increased by a subsequent treatment with fructose, sucrose or maltose in darkness, and they increased still further upon a treatment with glucose, sucrose or maltose under continuous light. These results indicate that the CHS1, CHS2 and CHS3 transcripts are expressed in various organs and respond to sugars in young leaves in a similar manner. The effect of continuous light is also discussed.