Hecogenin a Plant Derived Small Molecule as an Antagonist to BACE-1: A Potential Target for Neurodegenerative Disorders.

The field of drug discovery has recognized the significance of computer-aided drug design. Recent advancements in structure identification and characterization, bio-computational science and molecular biology have significantly contributed to the development of novel treatments for various diseases. Alzheimer's disease is prevalent in over 50 million affected people, with the pathological condition of amyloidal plaque formation by the beta-amyloidal peptide that results in lesions of the patient's brain, thus making the target prediction and treatment a hurdle. In this study, we evaluated the potential of 54 bioactive compounds from Justicia adhatoda L. and Sida cordifolia L. identified through LC-MS/MS against the ß-site amyloid precursor cleaving enzyme (beta-secretase) that results in the formation of amyloidal plaques. To study the drug-likeness of the phytocompounds, Lipinski's rule of five for ADME profiling and toxicity prediction was performed. Molecular docking was performed using auto-dock tool of PyRx software; molecular dynamic simulations were performed using the Schrodinger suite. Molecular docking against BACE-1 protein revealed that hecogenin, identified from S. cordifolia has a broad spectrum of pharmacological applications and a binding affinity score of -11.3 kcal/Mol. The Hecogenin-BACE-1 protein complex was found to be stable after 30 ns of MD simulation, resulting in its substantial stability. Further studies focusing on the in vivo neuroprotective activity of hecogenin against the disease will pave the way for efficient drug discovery from natural sources in a precise manner.

Integrated Metabolite and Transcriptome Profiling-Mediated Gene Mining of Sida cordifolia Reveals Medicinally Important Genes.

Sida cordifolia is a medicinal shrub that is conventionally used in the Indian system of medicine;however, the genes contributing to its medicinal properties have been minimally explored, thus limiting its application. High-throughputsequencing and Liquid Chromatography with tandem mass spectrometry(LC-MS/MS) technologies were applied to unravel the medicinally important bioactive compounds. As a result, transcriptomic sequencing generated more than 12 GB of clean data, and 187,215 transcripts were obtained by de novoassembly. These transcripts were broadly classified into 20 classes, based on the gene ontology classification, and 6551 unigenes were annotated using Kyoto Encyclopedia of Genes and Genomes (KEGG) database with more than 142 unigenes involved in the biosynthesis of secondary metabolites. LC-MS/MS analysis of three tissues of Sida cordifolia revealed that acacetin and procyanidin are some important metabolites identified thatcontribute to its medicinal value. Several key enzymes witha crucial role in phenylpropanoid and flavonoid biosynthetic pathways were identified, especially phenylalanine ammonia lyase, which might be an important rate-limiting enzyme. Real-Time Quantitative Reverse Transcription Polymerase chain reaction (qRT-PCR) analysis revealed enzymes, such as Phenylalanine ammonia lyase (PAL), Cinnamyl alcohol dehydrogenase 1 (CAD), Cinnamoyl-CoA reductase 1 (CF1) and Trans cinnamate 4-monooxygenase(TCM), which were predominantly expressed in root compared to leaf and stem tissue. The study provides a speculative insight for the screening of active metabolites and metabolic engineering in Sida cordifolia.

De novo transcriptome analysis of Justicia adhatoda reveals candidate genes involved in major biosynthetic pathway.

BACKGROUND: Justicia adhatoda is an important medicinal plant traditionally used in the Indian system of medicine and the absence of molecular-level studies in this plant hinders its wide use, hence the study was aimed to analyse the genes involved in its various pathways. METHODS AND RESULTS: The RNA isolated was subjected to Illumina sequencing. De novo assembly was performed using TRINITY software which produced 171,064 transcripts with 55,528 genes and N50 value of 2065 bp, followed by annotation of unigenes against NCBI, KEGG and Gene ontology databases resulted in 105,572 annotated unigenes and 40,288 non-annotated unigenes. A total of 5980 unigenes were mapped to 144 biochemical pathways, including the metabolism and biosynthesis pathways. The pathway analysis revealed the major transcripts involved in the tryptophan biosynthesis with TPM values of 6.0903, 33.6854, 11.527, 1.6959, and 8.1662 for Anthranilate synthase alpha, Anthranilate synthase beta, Arogenate/Prephenate dehydratase, Chorismate synthase and Chorismate mutase, respectively. The qRT-PCR validation of the key enzymes showed up-regulation in mid mature leaf when compared to root and young leaf tissue. A total of 16,154 SSRs were identified from the leaf transcriptome of J. Adhatoda ,which could be helpful in molecular breeding. CONCLUSIONS: The study aimed at identifying transcripts involved in the tryptophan biosynthesis pathway for its medicinal properties, as it acts as a precursor to the acridone alkaloid biosynthesis with major key enzymes and their validation. This is the first study that reports transcriptome assembly and annotation of J. adhatoda plant.

Preliminary phytochemical screening, Antibacterial potential and GC-MS analysis of two medicinal plant extracts.

The presence study was aimed to catalyze the primary metabolites and their confirmation by using GC-MS analysis and antibacterial potential of leaf extract of two important medicinal plant viz., Eucalyptus and Azadirachta indica. The antibacterial potential of the methanol leaf extract of the studied species was tested against Escherichia coli, Pseudomonas aeruginosa, Klebsiellap neumoniae, Streptococcus pyogens, Staphylococcus aureus using by agar well diffusion method. The higher zone of inhibition (16mm) was observed against the bacterium Pseudomonas aeruginosa at 100µl concentration of methanol leaf extract. Preliminary phytochemical analysis of studied species shows that presence of phytochemical compounds like steroids, phenolic compounds and flavonoids. GC-MS analysis confirms the occurrence of 20 different compounds in the methanol leaf extract of the both studied species.

Susceptibility against grey blight disease-causing fungus Pestalotiopsis sp. in tea (Camellia sinensis (L.) O. Kuntze) cultivars is influenced by anti-oxidative enzymes.

Reactive oxygen species (ROS) production is the first level of response by a host during stress. Even though the ROS are toxic to cell, when present in a limited amount, they act as a signalling molecule for the expression of defence-related genes and later are scavenged by either enzymatic or non-enzymatic mechanisms of the host. The different anti-oxidative enzymes like glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APO), peroxidase (POD) and polyphenol oxidase (PPO) were estimated, and their activities were compared between infected and healthy leaves of the tolerant and susceptible cultivars of tea. The infected leaves of the susceptible cultivars registered higher amount of enzyme activity when compared with the tolerant cultivars. The study reveals that the more anti-oxidative enzymes, the more susceptible the cultivar will be.

Analysis of dormant bud (Banjhi) specific transcriptome of tea (Camellia sinensis (L.) O. Kuntze) from cDNA library revealed dormancy-related genes.

Bud dormancy is of ecological and economical interest due to its impact on tea (Camellia sinensis (L.) O. Kuntze) plant growth and yield. Growth regulation associated with dormancy is an essential element in plant's life cycle that leads to changes in expression of large number of genes. In order to identify and provide a picture of the transcriptome profile, cDNA library was constructed from dormant bud (banjhi) of tea. Sequence and gene ontology analysis of 3,500 clones, in many cases, enabled their functional categorization concerning the bud growth. Based on the cDNA library data, the putative role of identified genes from tea is discussed in relation to growth and dormancy, which includes morphogenesis, cellular differentiation, tropism, cell cycle, signaling, and various metabolic pathways. There was a higher representation of unknown processes such as unknown molecular functions (65.80 %), unknown biological processes (62.46 %), and unknown cellular components (67.42 %). However, these unknown transcripts represented a novel component of transcripts in tea plant bud growth and/or dormancy development. The identified transcripts and expressed sequence tags provides a valuable public resource and preliminary insights into the molecular mechanisms of bud dormancy regulation. Further, the findings will be the target of future expression experiments, particularly for further identification of dormancy-related genes in this species.

Identification of differentially expressed genes in dormant (banjhi) bud of tea (Camellia sinensis (L.) O. Kuntze) using subtractive hybridization approach.

Growth regulation associated with dormancy is an essential element in plant's life cycle that leads to changes in expression of large number of genes. Forward and reverse suppression subtractive hybridization (SSH) libraries were developed to identify and characterize the genes associated with bud (banjhi) dormancy in tea (Camellia sinensis (L.) O. Kuntze). Efficiency of subtraction was confirmed by comparing the abundance of ß-actin gene. A total of 17 and 45 unique sequences were obtained from forward and reverse SSH library respectively. Many of the differentially regulated genes have unknown (41.1% and 26.7%) or hypothetical functions (11.7% and 2.2%) in forward and reverse SSH library respectively, while others have a role in cell growth and metabolism. Further, semi-quantitative RT-PCR was carried out for selected genes to validate the quality of ESTs from SSH library. Gene Ontology analysis identified a greater association of these ESTs in cellular metabolic pathways and their relevance to bud dormancy. Based on the EST data, the putative role of identified genes from tea is discussed in relation to dormancy, which includes various metabolic and signalling pathways. We demonstrated that SSH is an efficient tool for enriching up- and down-regulated genes related to bud dormancy in tea. This study represents an attempt to investigate banjhi dormancy in tea under field conditions, and the findings indicate that there is a potential to develop new approaches to modulate dormancy in this species.