Impact of the Season on Total Polyphenol and Antioxidant Properties of Tea Cultivars of Industrial Importance in Northeast India.

Tocklai vegetative (TV) cultivars are extensively planted in the tea-growing regions of Northeast India. The present investigation explores the impact of season on the total polyphenol (TP) content and the antioxidant activity of thirty-one TV cultivars (TV1-TV31) and four other commercially popular cultivars, namely, Betjan, Kharijan, S.3A/3, and T.3E/3. The TP content of the cultivars was observed to be highest in the monsoon season, with values ranging from 230.57 to 283.53 mg g-1. In the pre-monsoon season and autumn, the TP content ranged from 197.87 to 256.77 mg g-1 and from 169.97 to 223.50 mg g-1, respectively. Antioxidant activity was measured through DPPH, ABTS, FRAP, and lipid peroxidation inhibition assays. The cultivars showed the highest antioxidant activity in the monsoon in tandem with TP content. A bivariate correlation indicated a highly significant (p ≤ 0.01) positive correlation of antioxidant activity with TP content (R2 = 0.83-0.96).

An Overview on Plant Derived Phenolic Compounds and Their Role in Treatment and Management of Diabetes.

Objectives: In recent decades, the trend for treating diabetes mellitus (DM) has shifted toward alternative medicines that are obtained from plant sources. Existing literature suggests that phenolic compounds derived from plants possess promising health-promoting properties. This study aimed to discuss the role of plant-derived phenolic compounds in the effective treatment and management of diabetes. Methods: Information about plant secondary metabolites, phenolic compounds, and their role in the treatment and management of diabetes was collected from different databases, such as Pubmed, ScienceDirect, Scopus, and Google Scholar. Keywords like secondary metabolites, phenolic compounds, simple phenol, flavonoids, lignans, stilbenes, and diabetes were searched. Research and review articles with relevant information were included in the study. Results: Anti-diabetic studies of the four major classes of phenolic compounds were included in this review. The plant-derived phenolic compounds were reported to have potent anti-diabetic activities. However, each class of phenolic compounds was found to behave differently according to various mechanisms. Conclusion: The obtained results suggest that phenolic compounds derived from natural sources display promising anti-diabetic activities. Based on the available information, it can be concluded that phenolic compounds obtained from various natural sources play key roles in the treatment and management of diabetes.

Impact of processing method on selected trace elements content of green tea: Does CTC green tea infusion possess risk towards human health?

This study reported the content of selected metals, viz. cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) as well as non-carcinogenic risks of orthodox green tea and CTC (crush, tear and curl) green tea (Camellia sinensis L.) in India. Results revealed that significantly higher amount of Cr (1.26-10.48 mg kg-1), Cu (13.40-22.73 mg kg-1), Fe (54.14-99.65 mg kg-1), Ni (3.43-7.09 mg kg-1), and Zn (25.04-38.04 mg kg-1) in CTC green tea than orthodox one. However, no definite trend was observed for Cd and Pb, with overall contents ranged from 6.68 to 23.32 µg kg-1 and 0.04 to 0.13 mg kg-1, respectively. The extraction of the elements in tea infusion was higher for CTC green tea. The hazard quotient and hazard index values of all the studied metals were less than unity, confirming no significant health effect for consumers assuming drinking of 750 mL tea infusion prepared from 10 g green tea per day per person.

Changes in major catechins, caffeine, and antioxidant activity during CTC processing of black tea from North East India.

Tea (Camellia sinensis L.) leaves undergo complex chemical transformations during black tea processing. However, the dynamic chemical changes during tea processing have not been explored in popular cultivars of North East India. In this study, changes in catechins, caffeine, total polyphenol (TP) and formation of theaflavins were examined throughout the different stages of CTC (curl, tear and crush) black tea processing based on UPLC metabolomic analysis along with antioxidant activity for eight cultivars viz. S.3A/3, TV1, TV7, TV9, TV17, TV22, TV23 and TV25. The results demonstrated that the most prolific changes were observed after complete maceration of tea leaves. The total catechin, (-)-epigallocatechin gallate and (-)-epicatechin gallate levels decreased by 96, 97 and 89%, respectively as the processing progressed from fresh leaves to black tea. The TP level decreased by 26 to 37% throughout the processing path. The caffeine content increased by 18% during processing. The total theaflavin reached the highest level at 20 min of fermentation and then decreased by 13 to 36% at 40 min. Cultivar TV23 and S.3A/3 had a high content of total theaflavin with 17.9 and 16.9 mg g-1, respectively. The antioxidant activity was observed to be decreased by 31% for the black tea as compared to fresh leaves. It is also observed that the total phenolic content exerted a greater effect on antioxidant activity rather than catechins and theaflavins. This study provides an insightful observation of black tea processing which will immensely help in improving the quality of processed tea.

Quality characteristics of infusion and health consequences: a comparative study between orthodox and CTC green teas.

The present study compares the effects of two green tea processing techniques, viz. orthodox and CTC (curl, tear and crush) on the quality parameters and sensory profiles under the geographical and climatic conditions of Assam, India. The results showed that CTC green tea infusions had 13.3, 7.5, 7.1, 9.8, 5.4, 17.3, 17.1 and 18.6% more total polyphenol, total catechin, (-)-epigallocatechin-3-gallate (EGCG), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), (-)-epicatechin (EC), water extract and theanine level, respectively than the infusions prepared from orthodox green tea. The sensory evaluation preferred the orthodox over CTC processing mode. Risk assessment with daily consumption of five cups (10 g) of green tea reveals that the EGCG level is free from the risk of hepatotoxicity and caffeine will not inflict any health hazard.

Genetic evolution and codon usage analysis of NKX-2.5 gene governing heart development in some mammals.

NKX-2.5 gene is responsible for cardiac development and its targeted disruption apprehends cardiac development at the linear heart tube stage. Bioinformatic analysis was employed to investigate the codon usage pattern and dN/dS of mammalian NKX-2.5 gene. The relative synonymous codon usage analysis revealed variation in codon usage and two synonymous codons namely ATA (Ile) and GTA (Val) were absent in NKX-2.5 gene across selected mammalian species suggesting that these two codons were possibly selected against during evolution. Parity rule 2 analysis of two and four fold amino acids showed CT bias whereas six-fold amino acids revealed GA bias. Neutrality analysis suggests that selection played a prominent role while mutation had a minor role. The dN/dS analysis suggests synonymous substitution played a significant role and it negatively correlated with p-distance of the gene. Purifying natural selection played a dominant role in the genetic evolution of NKX-2.5 gene in mammals.

Chronic obstructive pulmonary disease: A crosstalk on nucleotide compositional dynamics and codon usage patterns of the genes involved in disease.

Chronic obstructive pulmonary disease (COPD), a lung disease, affects a large number of people worldwide, leading to death. Here, we analyzed the compositional features and trends of codon usage of the genes influencing COPD to understand molecular biology, genetics, and evolutionary relationships of these genes as no work was reported yet. Coding sequences of COPD genes were found to be rich in guanine-cytosine (GC) content. A high value (34-60) of the effective number of codons of the genes indicated low codon usage bias (CUB). Correspondence analysis suggested that the COPD genes were distinct in their codon usage patterns. Relative synonymous codon usage values of codons differed between the more preferred codons and the less-preferred ones. Correlation analysis between overall nucleotides and those at third codon position revealed that mutation pressure might influence the CUB of the genes. The high correlation between GC12 and GC3 signified that directional mutation pressure might have operated at all the three codon positions in COPD genes.

DNA compositional dynamics and codon usage patterns of M1 and M2 matrix protein genes in influenza A virus.

Influenza A virus subtype H3N2 has been a serious health issue across the globe with approximately 36 thousand annual casualties in the United States of America only. Co-circulation in avian, swine and human hosts has led to frequent mutations in the virus genome, due to which development of successful antivirals against the virus has become a formidable challenge. Recently, focussed research is being carried out targeting the matrix proteins of this strain as vaccine candidates. This study is carried out to unravel the key features of the genes encoding the matrix proteins that manoeuvre the codon usage profile in the H3N2 strains. The findings reveal differential codon choice for both matrix protein 1 and matrix protein 2. The overall codon usage bias is less pronounced in both the datasets which is evident from higher value of effective number of codons (>55). Comparison of the codon usage for both the genes under study with that of humans revealed that the viral codon usage is not fully optimized for the human host conditions. Both the genes enrolled in the study showed variation which was reflected in almost all the indices used for codon usage studies. Neutrality analysis revealed a weak role of mutation pressure while selection was the major contributor towards codon usage.

Nasopharyngeal carcinoma: understanding its molecular biology at a fine scale.

Among all cancers, the incidence of nasopharyngeal carcinoma (NPC) is quite high in the endemic regions. NPC is a head and neck cancer with poor survival rate, and is rare throughout most of the world but common in certain geographic areas, like southern Asia and some regions of North East India (Nagaland, Manipur, and Mizoram). A clear understanding of its etiology is still lacking, but NPC is widely suspected to be the result of both genetic susceptibility and exposure to environmental factors or Epstein-Barr virus infection. Diagnosis in the early stages needs a high index of clinical acumen, and, although most cross-sectional imaging investigations show the tumor with precision, confirmation is dependent on histology. This article reviews all related research reports on NPC histopathological classifications worldwide that have been published within the past 20 years. Genome-wide association studies suggested that there might be common disease mechanisms between that disease and NPC. Personalized management rules, quality assessment of life in patients, and an understanding of the essential mechanisms of recurrence could be directed toward research into recurrent NPC. Hence, this literature would offer otolaryngologists a deeper insight into the etiological and management aspects of NPC.

Codon usage and expression level of human mitochondrial 13 protein coding genes across six continents.

The study of codon usage coupled with phylogenetic analysis is an important tool to understand the genetic and evolutionary relationship of a gene. The 13 protein coding genes of human mitochondria are involved in electron transport chain for the generation of energy currency (ATP). However, no work has yet been reported on the codon usage of the mitochondrial protein coding genes across six continents. To understand the patterns of codon usage in mitochondrial genes across six different continents, we used bioinformatic analyses to analyze the protein coding genes. The codon usage bias was low as revealed from high ENC value. Correlation between codon usage and GC3 suggested that all the codons ending with G/C were positively correlated with GC3 but vice versa for A/T ending codons with the exception of ND4L and ND5 genes. Neutrality plot revealed that for the genes ATP6, COI, COIII, CYB, ND4 and ND4L, natural selection might have played a major role while mutation pressure might have played a dominant role in the codon usage bias of ATP8, COII, ND1, ND2, ND3, ND5 and ND6 genes. Phylogenetic analysis indicated that evolutionary relationships in each of 13 protein coding genes of human mitochondria were different across six continents and further suggested that geographical distance was an important factor for the origin and evolution of 13 protein coding genes of human mitochondria.

Insights into the Usage of Nucleobase Triplets and Codon Context Pattern in Five Influenza A Virus Subtypes.

Influenza A virus is a single-stranded RNA virus with a genome of negative polarity. Owing to the antigenic diversity and cross concrete shift, an immense number of novel strains have developed astronomically over the years. The present work deals with the codon utilization partialness among five different influenza A viruses isolated from human hosts. All the subtypes showed the homogeneous pattern of nucleotide utilization with a little variation in their utilization frequencies. A lower bias in codon utilization was observed in all the subtypes as reflected by higher magnitudes of an efficacious number of codons. Dinucleotide analysis showed very low CpG utilization and a high predilection of A/T-ending codons. The H5N1 subtype showed noticeable deviation from the rest. Codon pair context analysis showed remarkable depletion of NNC-GNN and NNT-ANN contexts. The findings alluded towards GC-compositional partialness playing a vital role, which is reflected in the consequential positive correlation between the GC contents at different codon positions. Untangling the codon utilization profile would significantly contribute to identifying novel drug targets that will pacify the search for antivirals against this virus.

Stress induced MAPK genes show distinct pattern of codon usage in Arabidopsis thaliana, Glycine max and Oryza sativa.

Mitogen activated protein kinase (MAPK) genes provide resistance to various biotic and abiotic stresses. Codon usage profiling of the genes reveals the characteristic features of the genes like nucleotide composition, gene expressivity, optimal codons etc. The present study is a comparative analysis of codon usage patterns for different MAPK genes in three organisms, viz. Arabidopsis thaliana, Glycine max (soybean) and Oryza sativa (rice). The study has revealed a high AT content in MAPK genes of Arabidopsis and soybean whereas in rice a balanced AT-GC content at the third synonymous position of codon. The genes show a low bias in codon usage profile as reflected in the higher values (50.83 to 56.55) of effective number of codons (Nc). The prediction of gene expression profile in the MAPK genes revealed that these genes might be under the selective pressure of translational optimization as reflected in the low codon adaptation index (CAI) values ranging from 0.147 to 0.208.

Compositional Constraint Is the Key Force in Shaping Codon Usage Bias in Hemagglutinin Gene in H1N1 Subtype of Influenza A Virus.

It is vital to unravel the codon usage bias in order to gain insights into the evolutionary forces dictating the viral evolution process. Influenza A virus has attracted attention of many investigators over the years due to high mutation rate and being cross-specific shift operational in the viral genome. Several authors have reported that the codon usage bias is low in influenza A viruses, citing mutational pressure as the decisive force shaping up the codon usage in these viruses. In this study, complete coding sequences of hemagglutinin genes for H1N1 subtype of influenza A virus have been explored for the possible codon usage bias acting upon these genes. The results indicate overall low bias with peaking ENC values. The GC content is found to be substantially low as against AT content in the silent codon sites. Significant correlations were observed in between the compositional parameters versus AT3, implying the possible role of the latter in shaping codon usage profile in the viral hemagglutinin. The data showed conspicuously that the sequences were A redundant with most codons preferring nucleotide A over others in the third synonymous codon site. The results indicated the pivotal role of compositional pressure affecting codon usage in this virus.