EXPLORING THE ANTIOBESITY AND ANTIOXIDANT POTENTIAL OF THE METHANOLIC EXTRACT OF CAMELLIA SINENSIS

The escalating problem of obesity has become a cause of great concern in the world today as it leads to adverse effects on human health, including cardiovascular diseases, cancer etc. The major causes of obesity may be attributed to sedentary lifestyle and bad food habits. Conventional modalities to tackle obesity are not free from side-effects. Urgency of a novel, nontoxic means needs to be developed to control obesity. In this study we aim to screen the phytochemical compounds of Camellia Sinensis and evaluate its antiobesity and antioxidant effects. The methanolic extract of Camellia Sinensis was analyzed for its phytochemical screening and assayed for its in-vitro activity against pancreatic lipase, its antioxidant potential and quantitative estimation of flavonoids and phenolics were done. The methanolic extract of Camellia Sinensis strongly inhibited pancreatic lipase by 63% and it also possesses a strong antioxidant effect and there was a significant positive correlation between phenolics, flavonoids and with alkaloid contents. From these results, it could be concluded that methanolic extracts of Camellia Sinensis possesses antipancreatic lipase compounds. It also possesses antioxidant effect. It is suggested that the phytochemical compounds from there plants may be applied for the prevention and treatment of obesity or hyperlipidemia. Keywords: Obesity, Camellia Sinensis, Pancreatic lipase, Antioxidant, Phenolic

In Vitro Regeneration of Tea (Camellia sinensis (L). O. Kuntze) By Somatic Embryogenesis from Immature Cotyledon Tissues

Tea (Camellia sinensis) is the world's most popular beverage plant, as well as an important plantation crop with high commercial value. It has been maintained for centuries through conventional vegetative propagation. Tea clonal propagation in vitro has the advantage of producing a large number of elite plants. If an efficient in vitro regeneration technology is available, this technique could be exploited for selection of tea plants for desired trait. The selected plants could be later on multiplied through in vitro or ex vitro techniques. The study aimed to induced somatic embryogenesis from immature embryo explants to genetic variaton. Different concentrations of phenylboronic acid with benzyladenine and phenylboronic acid with kinetin were tested in MS medium with 30 g/L sucrose and 8 g/L agar. MS medium without any plant growth regulators was used as control group. Considering the embryo survival rate, 1.5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 kinetin produced highest result as 87.3% while lowest was in control group as 36.7%. The highest plant regeneration rate was found in 1,5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 kinetin and 1.5 mg/ L-1 phenylboronic acid + 1 mg/ L-1 benzyladenine medium respectively as 58.3% and 55.6%. Kinetin treatment with increasing phenylboronic acid concentrations gave the best results in terms of somatic embryo survival rate. Also, kinetin treatment produced better results when compared to benzyladenine concentrations.

Transcriptomics analysis reveals the signal transduction mechanism of brassinolides in tea leaves and its regulation on the growth and development of Camellia sinensis

Background Brassinosteroids (BRs) are a type of sterol plant hormone that play an important role in various biochemical and physiological reactions such as promoting cell growth, increasing biomass, and improving stress resistance. Results To investigate the regulatory and molecular mechanism of BRs on the growth and development of tea plants (Camellia sinensis L.), changes in cell structure and gene expression levels of tea leaves treated with exogenous BRs were analyzed by electron microscopy and high-throughput Illumina RNA-Seq technology. The results showed that the number of starch granules in the chloroplasts and lipid globules increased and thylakoids expanded after BR treatment compared with the control. Transcriptome analysis showed that in the four BR treatments (CAA: BR treatment for 3 h, CAB: BR treatment for 9 h, CAC: BR treatment for 24 h, and CAD: BR treatment for 48 h), 3861 (1867 upregulated and 1994 downregulated), 5030 (2461 upregulated and 2569 downregulated), 1626 (815 upregulated and 811 downregulated), and 2050 (1004 upregulated and 1046 downregulated) differentially expressed genes were detected, respectively, compared with CAK (BR treatment for 0 h). Using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, metabolic pathway enrichment analysis showed that the differentially expressed genes of CAA vs. CAK, CAB vs. CAK, CAC vs. CAK, and CAD vs. CAK significantly enriched the functional categories of signal transduction, cell cycle regulation, and starch, sucrose, and flavonoid biosynthesis and metabolism pathways. We also found that after spraying BR, the key genes for caffeine synthesis were downregulated. The results of qRT-PCR coincided with the findings of transcriptomic analysis. Conclusions The present study improved our understanding of the effects of BRs on the growth and development of tea leaves and laid the foundation for the in-depth analysis of signal transduction pathways of BRs in tea leaves.

Correction to: In silico structural homology modelling of EST073 motif coding protein of tea Camellia sinensis (L)

An amendment to this paper has been published and can be accessed via the original article.

Efeito de diferentes polifenóis frente a neurotoxicidade induzida por ácido quinolínico em células gliais U87-MG

Doenças neurodegenerativas (DN) são desordens altamente debilitantes relacionadas ao envelhecimento, e a disfunção mitocondrial, estresse oxidativo e nitrosativo (EON) têm sido associados com as manifestações clínicas desse grupo de patologias. As mitocôndrias se destacam como organelas cruciais na relação entre a neurodegeneração e a neuroinflamação, e nesse sentido, os polifenóis são considerados promissores enquanto fármacos que têm como alvo as mitocôndrias. Compostos fenólicos são capazes de regular as mitocôndrias através do controle de seu estado redox, função e sistema apoptótico. Neste trabalho investigou-se o potencial neuroprotetor dos extratos de Araucaria angustifolia (AAE) e Camellia sinensis (GT), bem como de seis compostos isolados (resveratrol, ácido gálico, ácido elágico, catequina, epicatequina e proantocianidinas) em um modelo de neurodegeneração usando ácido quinolínico (AQ). Células gliais U87-MG foram pré-tratadas com AAE ou GT ou um dos compostos fenólicos por 1 hora e, então, expostas ao AQ por 24 horas. As células expostas ao AQ apresentaram diminuição da viabilidade, produção exacerbada de espécies reativas de oxigênio (EROs), redução do potencial de membrana mitocondrial e aumento da resposta inflamatória. Apesar dos resultados similares encontrados com o GT e o AAE, este último se destacou por ser capaz de prevenir todos os parâmetros testados neste trabalho. Em conclusão, sugere-se que o AAE apresenta-se como um agente em potencial para a prevenção de DN relacionadas com a disfunção mitocondrial associada ao EON.

Systematic Analysis of the R2R3-MYB Family in Camellia sinensis: Evidence for Galloylated Catechins Biosynthesis Regulation

The R2R3-MYB transcription factor (TF) family regulates metabolism of phenylpropanoids in various plant lineages. Species-expanded or specific MYB TFs may regulate species-specific metabolite biosynthesis including phenylpropanoid-derived bioactive products. Camellia sinensis produces an abundance of specialized metabolites, which makes it an excellent model for digging into the genetic regulation of plant-specific metabolite biosynthesis. The most abundant health-promoting metabolites in tea are galloylated catechins, and the most bioactive of the galloylated catechins, epigallocatechin gallate (EGCG), is specifically relative abundant in C. sinensis. However, the transcriptional regulation of galloylated catechin biosynthesis remains elusive. This study mined the R2R3-MYB TFs associated with galloylated catechin biosynthesis in C. sinensis. A total of 118 R2R3-MYB proteins, classified into 38 subgroups, were identified. R2R3-MYB subgroups specific to or expanded in C. sinensis were hypothesized to be essential to evolutionary diversification of tea-specialized metabolites. Notably, nine of these R2R3-MYB genes were expressed preferentially in apical buds (ABs) and young leaves, exactly where galloylated catechins accumulate. Three putative R2R3-MYB genes displayed strong correlation with key galloylated catechin biosynthesis genes, suggesting a role in regulating biosynthesis of epicatechin gallate (ECG) and EGCG. Overall, this study paves the way to reveal the transcriptional regulation of galloylated catechins in C. sinensis.