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Stilbenes, a Versatile Class of Natural Metabolites for InflammationAn Overview
Stilbenes are polyphenolic allelochemicals synthesized by plants, especially grapes, peanuts, rhubarb, berries, etc., to defend themselves under stressful conditions. They are now exploited in medicine for their antioxidant, anti-proliferative and anti-inflammatory properties. Inflammation is the immune systems response to invading bacteria, toxic chemicals or even nutrient-deprived conditions. It is characterized by the release of cytokines which can wreak havoc on healthy tissues, worsening the disease condition. Stilbenes modulate NF-?B, MAPK and JAK/STAT pathways, and reduce the transcription of inflammatory factors which result in maintenance of homeostatic conditions. Resveratrol, the most studied stilbene, lowers the Michaelis constant of SIRT1, and occupies the substrate binding pocket. Gigantol interferes with the complement system. Besides these, oxyresveratrol, pterostilbene, polydatin, viniferins, etc., are front runners as drug candidates due to their diverse effects from different functional groups that affect bioavailability and molecular interactions. However, they each have different thresholds for toxicity to various cells of the human body, and thus a careful review of their properties must be conducted. In animal models of autoinflammatory diseases, the mode of application of stilbenes is important to their absorption and curative effects, as seen with topical and microemulsion gel methods. This review covers the diversity seen among stilbenes in the plant kingdom and their mechanism of action on the different inflammatory pathways. In detail, macrophages contribution to inflamed conditions in the liver, the cardiac, connective and neural tissues, in the nephrons, intestine, lungs and in myriad other body cells is explored, along with detailed explanation on how stilbenes alleviate the symptoms specific to body site. A section on the bioavailability of stilbenes is included for understanding the limitations of the natural compounds as directly used drugs due to their rapid metabolism. Current delivery mechanisms include sulphonamides, or using specially designed synthetic drugs. It is hoped that further research may be fueled by this comprehensive work that makes a compelling argument for the exploitation of these compounds in medicine. 2023 by the authors. -
Biotechnological approaches for the production of hypericin and other important metabolites from the genus Hypericum
Hypericin, a polycyclic naphthodianthrone and active plant pigment with the molecular formula C30H16O8, is a crucial phytochemical extracted from the dark-colored glands present on the aerial parts of the genus Hypericum. It is biosynthesized through the polyketide pathway by plant-specific type III polyketide synthases (PKSs). In addition to hypericin, the genus Hypericum is rich in various classes of phytochemicals. Alongside other bioactive compounds like hyperforin and flavonoids, hypericin exhibits antidepressant activity. Recently, hypericin has gained increased importance in the research due to its unique properties. Its photodynamic nature makes it an effective natural photosensitizer, extending its use in investigating skin disorders. Moreover, hypericin demonstrates antiviral and antitumoral properties. Despite its effectiveness in treating cancers and neurological disorders, hypericin production faces challenges due to its site-specific nature. Conventional methods struggle to meet the growing demand for hypericin. Biotechnological approaches, including plant tissue culture and bioreactor-based large-scale production, offer promising solutions to address this demand. This review focuses on various plant tissue culture techniques, such as cell and organ culture, and elucidates their biosynthetic pathways. It also discusses hypericin production using elicitation strategies involving biotic and abiotic components, as well as genetic engineering approaches to enhance hypericin yields. Bioreactor-scale production presents significant potential for sustainable hypericin production. Further advancements in understanding and engineering biosynthetic pathways hold promise for unlocking new avenues in hypericin production. The Author(s), under exclusive licence to Springer Nature B.V. 2024. -
The Role of Nanoparticles in Response of Plants to Abiotic Stress at Physiological, Biochemical, and Molecular Levels
In recent years, the global agricultural system has been unfavorably impacted by adverse environmental changes. These changes in the climate, in turn, have altered the abiotic conditions of plants, affecting plant growth, physiology and production. Abiotic stress in plants is one of the main obstacles to global agricultural production and food security. Therefore, there is a need for the development of novel approaches to overcome these problems and achieve sustainability. Nanotechnology has emerged as one such novel approach to improve crop production, through the utilization of nanoscale products, such as nanofertilizer, nanofungicides, nanoherbicides and nanopesticides. Their ability to cross cellular barriers makes nanoparticles suitable for their application in agriculture. Since they are easily soluble, smaller, and effective for uptake by plants, nanoparticles are widely used as a modern agricultural tool. The implementation of nanoparticles has been found to be effective in improving the qualitative and quantitative aspects of crop production under various biotic and abiotic stress conditions. This review discusses various abiotic stresses to which plants are susceptible and highlights the importance of the application of nanoparticles in combating abiotic stress, in addition to the major physiological, biochemical and molecular-induced changes that can help plants tolerate stress conditions. It also addresses the potential environmental and health impacts as a result of the extensive use of nanoparticles. 2023 by the authors. -
Plant Secondary Metabolites: The Weapons for Biotic Stress Management
The rise in global temperature also favors the multiplication of pests and pathogens, which calls into question global food security. Plants have developed special coping mechanisms since they are sessile and lack an immune system. These mechanisms use a variety of secondary metabolites as weapons to avoid obstacles, adapt to their changing environment, and survive in less-than-ideal circumstances. Plant secondary metabolites include phenolic compounds, alkaloids, glycosides, and terpenoids, which are stored in specialized structures such as latex, trichomes, resin ducts, etc. Secondary metabolites help the plants to be safe from biotic stressors, either by repelling them or attracting their enemies, or exerting toxic effects on them. Modern omics technologies enable the elucidation of the structural and functional properties of these metabolites along with their biosynthesis. A better understanding of the enzymatic regulations and molecular mechanisms aids in the exploitation of secondary metabolites in modern pest management approaches such as biopesticides and integrated pest management. The current review provides an overview of the major plant secondary metabolites that play significant roles in enhancing biotic stress tolerance. It examines their involvement in both indirect and direct defense mechanisms, as well as their storage within plant tissues. Additionally, this review explores the importance of metabolomics approaches in elucidating the significance of secondary metabolites in biotic stress tolerance. The application of metabolic engineering in breeding for biotic stress resistance is discussed, along with the exploitation of secondary metabolites for sustainable pest management. 2023 by the authors. -
Amyotrophic Lateral Sclerosis: Insights and New Prospects in Disease Pathophysiology, Biomarkers and Therapies
Amyotrophic Lateral Sclerosis (ALS) is a severe neurodegenerative disorder marked by the gradual loss of motor neurons, leading to significant disability and eventual death. Despite ongoing research, there are still limited treatment options, underscoring the need for a deeper understanding of the diseases complex mechanisms and the identification of new therapeutic targets. This review provides a thorough examination of ALS, covering its epidemiology, pathology, and clinical features. It investigates the key molecular mechanisms, such as protein aggregation, neuroinflammation, oxidative stress, and excitotoxicity that contribute to motor neuron degeneration. The role of biomarkers is highlighted for their importance in early diagnosis and disease monitoring. Additionally, the review explores emerging therapeutic approaches, including inhibitors of protein aggregation, neuroinflammation modulators, antioxidant therapies, gene therapy, and stem cell-based treatments. The advantages and challenges of these strategies are discussed, with an emphasis on the potential for precision medicine to tailor treatments to individual patient needs. Overall, this review aims to provide a comprehensive overview of the current state of ALS research and suggest future directions for developing effective therapies. 2024 by the authors. -
Flavonoids as Potential Anti-Inflammatory Molecules: A Review
Hydroxylated polyphenols, also called flavonoids, are richly present in vegetables, fruits, cereals, nuts, herbs, seeds, stems, and flowers of numerous plants. They possess numerous medicinal properties such as antioxidant, anti-cancer, anti-microbial, neuroprotective, and anti-inflammation. Studies show that flavonoids activate antioxidant pathways that render an anti-inflammatory effect. They inhibit the secretions of enzymes such as lysozymes and ?-glucuronidase and inhibit the secretion of arachidonic acid, which reduces inflammatory reactions. Flavonoids such as quercetin, genistein, apigenin, kaempferol, and epigallocatechin 3-gallate modulate the expression and activation of a cytokine such as interleukin-1beta (IL-1?), Tumor necrosis factor-alpha (TNF-?), interleukin-6 (IL-6), and interleukin-8 (IL-8); regulate the gene expression of many pro-inflammatory molecules such s nuclear factor kappa-light chain enhancer of activated B cells (NF-?B), activator protein-1 (AP-1), intercellular adhesion molecule-1 (ICAM), vascular cell adhesion molecule-1 (VCAM), and E-selectins; and also inhibits inducible nitric oxide (NO) synthase, cyclooxygenase-2, and lipoxygenase, which are pro-inflammatory enzymes. Understanding the anti-inflammatory action of flavonoids provides better treatment options, including coronavirus disease 2019 (COVID-19)-induced inflammation, inflammatory bowel disease, obstructive pulmonary disorder, arthritis, Alzheimers disease, cardiovascular disease, atherosclerosis, and cancer. This review highlights the sources, biochemical activities, and role of flavonoids in enhancing human health. 2022 by the authors. Licensee MDPI, Basel, Switzerland. -
Biotechnological approaches for the production of gymnemic acid from Gymnema sylvestre R. Br.
Abstract : Diabetes is a chronic disease that affects several organs and can be treated using phytochemicals found in medicinal plants. Gymnema sylvestre (Asclepiadaceae) is one such medicinal plant rich in anti-diabetic properties. The plant is commonly known as madhunashini in Sanskrit because of its ability to cure diabetes (sugar). Gymnemic acid(GA) is a phytochemical (a triterpenoid saponin) responsible for the herbs main pharmacological activity. This secondary metabolite has a lot of potential as a phytochemical with pharmacological properties including nephroprotection, hypoglycemia, antioxidant, antimicrobial, and anti-inflammatory. Gymnema has acquired a lot of popularity in recent years due to its low side effects and high efficacy in healing diabetes, which has led to overexploitation by pharmaceutical enterprises for its biomass in the wild for the purification of gymnemic acid. Modern biotechnological techniques involving the establishment of cell and organ cultures from G. sylvestre will assist us in fulfilling the need for gymnemic acid production. The present review provides insights on the establishment of cell and organ cultures for the production of a potent antidiabetic molecule gymnemic acid. Further, the review also delves into the intricacies of the different strategies for improved production of gymnemic acid using various elicitors. There is huge potential for sustainable production of gymnemic acid which could be met by establishment of bioreactor scale production. Understanding and engineering the biosynthetic pathway could also lead to improved GA production. Key points: Gymnemic acid is one of the potential anti-diabetic molecules from madhunashini Cell and organ culture offers potential approach for gymnemic acid production Elicitation strategies have improved the gymnemic acid production Graphical Abstract: [Figure not available: see fulltext.] 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. -
Biotechnological Approaches for Production of Artemisinin, an Anti-Malarial Drug from Artemisia annua L.
Artemisinin is an anti-malarial sesquiterpene lactone derived from Artemisia annua L. (Aster-aceae family). One of the most widely used modes of treatment for malaria is an artemisinin-based combination therapy. Artemisinin and its associated compounds have a variety of pharmacological qualities that have helped achieve economic prominence in recent years. So far, research on the biosynthesis of this bioactive metabolite has revealed that it is produced in glandular trichomes and that the genes responsible for its production must be overexpressed in order to meet demand. Using biotechnological applications such as tissue culture, genetic engineering, and bioreactor-based approaches would aid in the upregulation of artemisinin yield, which is needed for the future. The current review focuses on the tissue culture aspects of propagation of A. annua and production of artemisinin from A. annua L. cell and organ cultures. The review also focuses on elicitation strategies in cell and organ cultures, as well as artemisinin biosynthesis and metabolic engineering of biosynthetic genes in Artemisia and plant model systems. 2022 by the authors. Licensee MDPI, Basel, Switzerland. -
Biotechnological Research Progress in Jatropha, a Biodiesel-Yielding Plant
Environmental pollution is one of the most pressing challenges in todays world. The main cause of this pollution is fuel emissions from automobiles and other sources. As industrialization progresses, we will be unable to compromise on the use of energy to power heavy machines and will be forced to seek out the best options. As a consequence, utilizing green fuel, such as biodiesel derived from natural sources, is a realistic option. Jatropha curcas L. (Euphorbiaceae) is recognized as the greatest feedstock for biodiesel production throughout the world, and it has gained a huge market value in the recent years. Conventional cultivation alone will not be sufficient to meet the global need for the plants biomass for the production of biodiesel. Adoption of plant tissue culture techniques that improve the biomass availability is an immediate need. The present review provides detailed information regarding in-vitro plant propagation (direct and indirect organogenesis), somatic embryogenesis, and acclimatization protocols of plantlets for stabilized production of biomass. The review also focuses on biotechnological approaches such as gene transformation studies, production of haploids, and double haploids for developing elite germplasm for high biomass and improved traits for the production of biodiesel. 2022 by the authors. Licensee MDPI, Basel, Switzerland. -
A study of quadratic thermal radiation and quadratic convection on viscoelastic material flow with two different heat source modulations
In many practical applications such as plastic manufacturing and the polymer industries, the temperature difference is substantially large as a result the density of the working fluid alters nonlinearly with temperature. Therefore, the nonlinear Boussinesq (NBA) approximation cannot be ignored, as it has a considerable impact on the flow and heat transport characteristics of the working fluid. Here, the non-Newtonian viscoelastic material flow driven by stretching of elastic sheet subjected to NBA and quadratic form of Rosseland thermal radiation is investigated. Two different heat source modulations, viz., exponential space-dependent heat source, and a temperature-related heat source are analyzed. The viscoelastic material obeys the quadratic Boussinesq approximation. The fluctuation of plate temperature is linear and the transpiration (plate mass suction) is also accounted. The Darcy law is employed for a porous medium. The dimensionless profiles of the velocity, heat transport rate, and temperature are simulated by solving the nonlinear two-point boundary value system by employing the finite difference-based routine. The significance of key parameters involved in the problem is studied on various flow fields via surface and streamline plots. It is found that the quadratic convection mechanism enhanced the Nusselt number; however, the quadratic thermal radiation aspect reduced the Nusselt number. The higher velocities are captured in the case of quadratic thermal convection as compared with its absence. Whereas this trend is quite opposite for the thermal field. The velocity of viscoelastic material positively correlated with the viscoelastic material parameter. Further, the outcome of this investigation helps in determining the key parameters which facilitate the desired heat transport rate. 2021 Elsevier Ltd -
Spectral quasi-linearization and irreversibility analysis of magnetized cross fluid flow through a microchannel with two different heat sources and Newton boundary conditions
Fluid flow in a microchannel with heat transport effects can be seen in various applications such as micro heat collectors, mechanicalelectromechanical systems, electronic device cooling, micro-air vehicles, and micro-heat exchanger systems. However, little is known about the consequence of internal heat source modulations on the flow of fluids in a microchannel. Therefore, in this work, the heat transfer of a magnetized cross fluid is carried out in a micro-channel subjected to two different heat source modulations. Entropy production analysis is also performed. The mathematical model consists of a cross fluid model. In addition, the effects of Joule heating, external magnetism, and the boundary conditions of Newton's heating are also examined. Determinant equations are constructed under steady-state conditions and parameterized using dimensionless variables. The numerical spectral quasi-linearization (SQLM) method was developed to interpret the Bejan number, entropy production, temperature, and velocity profiles. It is established that the power-law index of the cross fluid reduces the magnitude of the entropy production, velocity, and thermal field in the entire microchannel region. Furthermore, a larger Weissenberg number is capable of producing greater entropy, velocity, and thermal fields throughout the microchannel region. The variation in temperature distribution is more noticeable for the ESHS aspect than the THS aspect. The values of the pressure gradient parameter and the Eckert number must be kept high for maximum heat transport of the cross fluid. The entropy production of the cross fluid increases significantly with the physical aspects of Joule heating and convection heating in the system. 2021, The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature. -
Significance of exponential space-based heat source and inclined magnetic field on heat transfer of hybrid nanoliquid with homogeneousheterogeneous chemical reactions
Many chemical reactive methods, like combustion, catalysis, and biochemical involve homogeneousheterogeneous chemical reaction(HHCR). The collaboration amongthe heterogeneous and homogeneous reactions is exceedingly multifarious, including the creation and depletion both within the liquid and catalytic surfaces. Here, we observe the influences of Cuand Al2O3nanoparticles past an elongating sheet under HHCR. An inclined magnetic field with an acute angle is applied to the direction of the flow. Further, radiative heat, temperature, and exponential space-based heat source aspects are modifying the thermal equation. The governing nonlinear equations are deciphered by utilizing the RungeKutta-based shooting method. It is found that HHCRreduces the solute layer thickness, whereas the increase in the angle of inclination of applied magnetism thickens momentum layer thickness. 2021 Wiley Periodicals LLC -
Structural and physico-chemical evaluation of melatonin and its solution-state excited properties, with emphasis on its binding with novel coronavirus proteins
Melatonin is a natural hormone from the pineal gland that regulates the sleep-wake cycle. We examined the structure and physico-chemical properties of melatonin using electronic structure methods and molecular-mechanics tools. Density functional theory (DFT) was used to optimise the ground-state geometry of the molecule from frontier molecular orbitals, which were analysed using the B3LYP functional. As its electrons interacted with electromagnetic radiation, electronic excitations between different energy levels were analysed in detail using time-dependent DFT with CAM-B3LYP orbitals. The results provide a wealth of information about melatonin's electronic properties, which will enable the prediction of its bioactivity. Molecular docking studies predict the biological activity of the molecules against the coronavirus2 protein. Excellent docking scores of ?7.28, ?7.20, and ?7.06 kcal/mol indicate that melatonin can help to defend against the viral load in vulnerable populations. Hence it can be investigated as a candidate drug for the management of COVID. 2020 Elsevier B.V. -
Modernizing Electrical Grids with TCR-Based Flexible AC Transmission Systems
Modernizing electrical grids is imperative to meet the growing demand for reliable, efficient, and sustainable energy. Thyristor-Controlled Reactors (TCRs) are integral components of modern Flexible AC Transmission Systems (FACTS). These systems offer a robust solution for enhancing grid stability, improving power quality, and optimizing transmission efficiency, ensuring that electric grids can support future energy needs. TCR-based FACTS are a collection of technologies designed to enhance the controllability, stability, and power transfer capability of AC electrical grid systems. In this paper, we will discuss the role of TCRs in modernizing AC transmission systems and their role in addressing grid challenges and improving performance, highlighting their critical role in future grid infrastructure. To discuss the future prospects and developments in TCR technology, with ongoing advancements and research efforts paving the way for more efficient, reliable, and flexible grid management solutions. The Authors, published by EDP Sciences, 2024. -
An Area-Efficient Unique 4:1 Multiplexer Using Nano-electronic-Based Architecture
Quantum dot cellular automata computing methodology is a new way to develop systems with less power consumption. Nanotechnology-based computing technology has enabled the QCA principles to be more relevant with respect to the critical limitations of current VLSI-based design. In this paper, a novel 4:1 multiplexer design based on the QCA concept is presented. As compared to the previous designs of a multiplexer, this novel design is area efficient and power efficient. A five-input majority voter is used for the design of the multiplexer. The 4:1 multiplexer is constructed by making use of three 2:1 multiplexer. 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Exploring chatbot trust: Antecedents and behavioural outcomes
An awareness about the antecedents and behavioural outcomes of trust in chatbots can enable service providers to design suitable marketing strategies. An online questionnaire was administered to users of four major banking chatbots (SBI Intelligent Assistant, HDFC Bank's Electronic Virtual Assistant, ICICI bank's iPal, and Axis Aha) in India. A total of 507 samples were received of which 435 were complete and subject to analysis to test the hypotheses. Based on the results, it is found that the hypothesised antecedents, except interface, design, and technology fear factors, could explain 38.6% of the variance in the banking chatbot trust. Further, in terms of behavioural outcomes chatbot trust could explain, 9.9% of the variance in customer attitude, 11.4% of the variance in behavioural intention, and 13.6% of the variance in user satisfaction. The study provides valuable insights for managers on how they can leverage chatbot trust to increase customer interaction with their brand. By proposing and testing a novel conceptual model and examining the factors that impact chatbot trust and its key outcomes, this study significantly contributes to the AI marketing literature. 2023 The Authors -
The Mediating Effect of Employee Engagement: How Employee Psychological Empowerment Impacts the Employee Satisfaction? A Study of Maldivian Tourism Sector
This study aims to examine the mediation of employee engagement on the relationship between employee psychological empowerment and employee job satisfaction, which helps to retain more customers with better service. An empirical analysis was done on Maldivian resorts, and 243 employees were randomly selected from different resorts in the Maldives. The proposed model was tested using IBM SPSS AMOS 25. The results indicate that psychological empowerment had a significant effect on job satisfaction of the resort employees through employee engagement. The Maldivian economy is based on the tourism sector, and a significant amount of gross domestic product (GDP) depends on the tourism sector. Resorts and guesthouses are the power hubs for the economic development of the country, and employees are the primary source of service providers to tourists, which helps the resorts to retain their tourists. Hence, this study concludes that employees psychological empowerment and employees engagement are crucial to improve employee satisfaction. 2023 IMI. -
Information Management Capacity and Supply Chain Performance: Mediating Effects of Supply Chain Practices, Competencies and Concerns
The present study aims to identify the impact of the information management capacity (IMC) of an organization on its supply chain performance (SCP). Also, this study attempts to understand the mediating role of the various components of supply chain management, namely, practices, competencies and concerns. A survey instrument was used to collect primary data from 250 SMEs which were selected randomly. Structural equation modeling (SEM) technique is used to test the hypotheses using SmartPLS. The final model indicated that information management capacity significantly influences the supply chain performance and supply chain management components, namely supply chain competence, practices and concerns mediate the relationship between information management capacity and supply chain performance. The results of this study provide a significant contribution to the theory of resource-based view. The number of managerial perspectives for improving operational capabilities was explained in this study. 2021 Management Development Institute. -
Fear of COVID-19, workplace phobia, workplace deviance and perceived organizational support: A moderated mediation model
This paper aims to test a moderated-mediation model examining therelationships between Fear of COVID-19, workplace phobia, work deviance behaviourand perceived organizational support among hotel employees. An online questionnaire was administered to collect data, to which 481 responded. Data was collected from full-time frontline employees working in the Maldivian hospitality industry. The moderated-mediation model explained 44% of the variance in workplace deviance behaviourscan be predicted bythe fear of COVID-19, perceived organisational support and workplace phobia. The findingsshowthat perceived organizational support reduces the negative impact of COVID-19 fear on workplace phobia and deviance. Results suggest that to reduce the negative effect of the pandemic, organisations should adopt support measures across different managerial levels at different scales rather than providing one-size-fits-all solutions. 2023 The Authors. Stress and Health published by John Wiley & Sons Ltd. -
How Green Consumption Value Affects Green Consumer Behaviour: The Mediating Role of Consumer Attitudes Towards Sustainable Food Logistics Practices
The aim of the study is to identify the green consumption values and production patterns and understand how they impact consumer behaviour and purchase intention of green consumers, in particular, the environment-conscious youth in the city of Bangalore. The focus of the study is on the pre-purchase sustainable logistics of food products and how they impact behaviour and attitudes of green consumers. The theory of planned behaviour and social cognitive theory form the theoretical base for the current research. An online survey was conducted among 284 participants in and around the scope area. Confirmatory factor analysis and structural equation modelling were used to test the hypotheses. The results showed that green consumption values and consumer attitudes towards sustainable food logistics either directly or indirectly influence green purchase intention and environmentally conscious behaviour towards food products. The main contribution of this study is the identification of new multidimensional constructs which can be used to measure green consumer attitude in terms of sustainable food logistics practices in the Indian context. These findings will empower managers and future researchers to understand how sustainable food logistics practices can create green consumer attitudes. They will also assist food production companies to identify possible opportunities, developments and other benefits they can derive from following sustainable food logistics practices. 2021 Management Development Institute.