Annamalai University

Mangrove species are uniquely adapted to tropical and subtropical coasts, and although relatively low in number of species, mangrove forests provide at least US $1.6 billion each year in ecosystem services and support coastal livelihoods worldwide. Globally, mangrove areas are declining rapidly as they are cleared for coastal development and aquaculture and logged for timber and fuel production. Little is known about the effects of mangrove area loss on individual mangrove species and local or regional populations. To address this gap, species-specific information on global distribution, population status, life history traits, and major threats were compiled for each of the 70 known species of mangroves. Each species' probability of extinction was assessed under the Categories and Criteria of the IUCN Red List of Threatened Species. Eleven of the 70 mangrove species (16%) are at elevated threat of extinction. Particular areas of geographical concern include the Atlantic and Pacific coasts of Central America, where as many as 40% of mangroves species present are threatened with extinction. Across the globe, mangrove species found primarily in the high intertidal and upstream estuarine zones, which often have specific freshwater requirements and patchy distributions, are the most threatened because they are often the first cleared for development of aquaculture and agriculture. The loss of mangrove species will have devastating economic and environmental consequences for coastal communities, especially in those areas with low mangrove diversity and high mangrove area or species loss. Several species at high risk of extinction may disappear well before the next decade if existing protective measures are not enforced.

There has been considerable public and scientific interest in the use of phytochemicals derived from dietary components to combat human diseases. They are naturally occurring substances found in plants. Ferulic acid (FA) is a phytochemical commonly found in fruits and vegetables such as tomatoes, sweet corn and rice bran. It arises from metabolism of phenylalanine and tyrosine by Shikimate pathway in plants. It exhibits a wide range of therapeutic effects against various diseases like cancer, diabetes, cardiovascular and neurodegenerative. A wide spectrum of beneficial activity for human health has been advocated for this phenolic compound, at least in part, because of its strong antioxidant activity. FA, a phenolic compound is a strong membrane antioxidant and known to positively affect human health. FA is an effective scavenger of free radicals and it has been approved in certain countries as food additive to prevent lipid peroxidation. It effectively scavenges superoxide anion radical and inhibits the lipid peroxidation. It possesses antioxidant property by virtue of its phenolic hydroxyl group in its structure. The hydroxy and phenoxy groups of FA donate electrons to quench the free radicals. The phenolic radical in turn forms a quinone methide intermediate, which is excreted via the bile. The past few decades have been devoted to intense research on antioxidant property of FA. So, the present review deals with the mechanism of antioxidant property of FA and its possible role in therapeutic usage against various diseases.

In this paper, an aqueous extract of fresh leaves of Pedalium murex was used for the synthesis of silver (Ag) nanoparticles. Different biological methods are gaining recognition for the production of silver nanoparticles (AgNPs) due to their multiple applications. The use of plants in the green synthesis of nanoparticles emerges as a cost-effective and eco-friendly approach. Characterization of nanoparticles was done using different methods, which include; ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared (FTIR), powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray analysis (EDAX), fluorescence emission spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS), zeta potential and antibacterial activity. UV–visible spectrum of the aqueous medium containing silver nanoparticles showed absorption peak at around 430 nm. Fourier transform infrared spectra had shown that the biomolecule compounds were responsible for the reduction and capping material of silver nanoparticles. XRD study showed the particles to be crystalline in nature, with a face-centered cubic (fcc) structure. The size and stability were detected using DLS and zeta potential analysis. The antibacterial activity of AgNPs against generally found bacteria was assessed to find their potential use in silver-containing antibacterial product.

Water is vital for plant growth and development. Water-deficit stress, permanent or temporary, limits the growth and the distribution of natural vegetation and the performance of cultivated plants more than any other environmental factors do. Although research and practices aimed at improving water-stress resistance and water-use efficiency have been carried out for many years, the mechanism involved is still not clear. Further understanding and manipulating plant-water relations and water-stress tolerance at the scale of physiology and molecular biology can significantly improve plant productivity and environmental quality. Currently, post-genomics and metabolomics are very important to explore anti-drought gene resource in different life forms, but modern agricultural sustainable development must be combined with plant physiological measures in the field, on the basis of which post-genomics and metabolomics will have further a practical prospect. In this review, we discussed the anatomical changes and drought-tolerance strategies under drought condition in higher plants.

BACKGROUND: The cytochrome P450 (CYP) enzymes are membrane-bound hemoproteins that play a pivotal role in the detoxification of xenobiotics, cellular metabolism and homeostasis. Induction or inhibition of CYP enzymes is a major mechanism that underlies drug-drug interactions. CYP enzymes can be transcriptionally activated by various xenobiotics and endogenous substrates through receptor-dependent mechanisms. CYP enzyme inhibition is a principal mechanism for metabolism- based drug-drug interactions. Many chemotherapeutic drugs can cause drug interactions due to their ability to either inhibit or induce the CYP enzyme system. Predictions based on in silico analyses followed by validation have identified several microRNAs that regulate CYPs. Genetic polymorphisms and epigenetic changes in CYP genes may be responsible for inter-individual and interethnic variations in disease susceptibility and the therapeutic efficacy of drugs. OBJECTIVE: The present review is a comprehensive compilation of cytochrome P450 structure, function, pharmacogenetics, pharmacoepigenetics and clinical significance. CONCLUSION: Knowledge about the substrates, inducers, and inhibitors of CYP isoforms, as well as the polymorphisms of CYP enzymes may be used as an aid by clinicians to determine therapeutic strategy, and treatment doses for drugs that are metabolized by CYP gene products.

Azadirachta indica, commonly known as neem, has attracted worldwide prominence in recent years, owing to its wide range of medicinal properties. Neem has been extensively used in Ayurveda, Unani and Homoeopathic medicine and has become a cynosure of modern medicine. Neem elaborates a vast array of biologically active compounds that are chemically diverse and structurally complex. More than 140 compounds have been isolated from different parts of neem. All parts of the neem tree- leaves, flowers, seeds, fruits, roots and bark have been used traditionally for the treatment of inflammation, infections, fever, skin diseases and dental disorders. The medicinal utilities have been described especially for neem leaf. Neem leaf and its constituents have been demonstrated to exhibit immunomodulatory, anti-inflammatory, antihyperglycaemic, antiulcer, antimalarial, antifungal, antibacterial, antiviral, antioxidant, antimutagenic and anticarcinogenic properties. This review summarises the wide range of pharmacological activities of neem leaf.

Cancer is one of the major causes of death worldwide and chemotherapy is a major therapeutic approach for the treatment which may be used alone or combined with other forms of therapy. However, conventional chemotherapy suffers lack of aqueous solubility, lack of selectivity and multidrug resistance. Nanotherapeutics is rapidly progressing aimed to solve several limitations of conventional drug delivery systems. Nonspecific target of cancer chemotherapy leads to damage rapidly proliferating normal cells and can be significantly reduced through folate and transferrin mediated nanotherapeutics which are aimed to target cancerous cells. Multidrug resistance is challenge in cancer chemotherapy which can be significantly reversed by solid lipid nanoparticles, polymeric nanoparticles, mesoporous silica nanoparticles, nanoparticulated chemosensitizer, nanoparticluated poloxamer and magnetic nanoparticles. Hydrophobic nature of chemotherapeutics leads to poor aqueous solubility and low bioavailability which can be overcome by nanocrystals, albumin based nanoparticles, liposomal formulation, polymeric micelles, cyclodextrin and chitosan based nanoparticles. This review focuses the role of nanotherapeutics to overcome lack of selectivity, multidrug resistance and lack of aqueous solubility of conventional cancer chemotherapy.

Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric cancer varies in different parts of the world and among various ethnic groups. Despite advances in diagnosis and treatment, the 5-year survival rate of stomach cancer is only 20 per cent. Stomach cancer can be classified into intestinal and diffuse types based on epidemiological and clinicopathological features. The etiology of gastric cancer is multifactorial and includes both dietary and nondietary factors. The major diet-related risk factors implicated in stomach cancer development include high content of nitrates and high salt intake. Accumulating evidence has implicated the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of gastric cancer. The development of gastric cancer is a complex, multistep process involving multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, and signaling molecules. A plausible program for gastric cancer prevention involves intake of a balanced diet containing fruits and vegetables, improved sanitation and hygiene, screening and treatment of H. pylori infection, and follow-up of precancerous lesions. The fact that diet plays an important role in the etiology of gastric cancer offers scope for nutritional chemoprevention. Animal models have been extensively used to analyze the stepwise evolution of gastric carcinogenesis and to test dietary chemopreventive agents. Development of multitargeted preventive and therapeutic strategies for gastric cancer is a major challenge for the future.

Abundance, chemical composition and ecological risk of microplastics (MPs) in terrestrial and marine environments have merited substantial attention from the research communities. This is the first attempt to comprehend the ecological risk of MPs in sediments along the Indian coast using meta-data. Polymer hazard index (PHI), pollution load index (PLI) and potential ecological risk index (PERI) were used to evaluate the quality of sediments. Areas have high PHI values (>1000) due to the presence of polymers with high hazard scores such as polyamide (PA) and polystyrene (PS). According to PLI values, sediments along the west coast of India (WCI) are moderately contaminated with MPs (PLI: 3.03 to 15.5), whereas sediments along the east coast of India (ECI) are less contaminated (PLI: 1 to 6.14). The PERI values of sediments along the Indian coast showed higher ecological risk for the metropolitan cities, river mouths, potential fishing zones and the remote islands.

Breast cancer is the most common cancer and the most frequent cause of cancer death among women worldwide. Breast cancer is a complex, heterogeneous disease classified into hormone-receptor-positive, human epidermal growth factor receptor-2 overexpressing (HER2+) and triple-negative breast cancer (TNBC) based on histological features. Endocrine therapy, the mainstay of treatment for hormone-responsive breast cancer involves use of selective estrogen receptor modulators (SERMs), selective estrogen receptor downregulators (SERDs) and aromatase inhibitors (AIs). Agents that target estrogen receptor (ER) and HER2 such as tamoxifen and trastuzumab have been the most extensively used therapeutics for breast cancer. Crosstalk between ER and other signalling networks as well as epigenetic mechanisms have been envisaged to contribute to endocrine therapy resistance. TNBC, a complex, heterogeneous, aggressive form of breast cancer in which the cells do not express ER, progesterone receptor or HER2 is refractory to therapy. Several molecular targets are being explored to target TNBC including androgen receptor, epidermal growth factor receptor (EGFR), poly(ADP-ribose) polymerase (PARP), and vascular endothelial growth factor (VEGF). Receptors, protein tyrosine kinases, phosphatases, proteases, PI3K/Akt signalling pathway, microRNAs (miRs) and long noncoding RNAs (lncRNAs) are potential therapeutic targets. miR-based therapeutic approaches include inhibition of oncomiRs by antisense oligonucleotides, restoration of tumour suppressors using miR mimics, and chemical modification of miRs. The lnRNAs HOTAIR, SPRY4-IT1, GAS5, and PANDAR, new players in tumour development and prognosis may have theranostic applications in breast cancer. Several novel classes of mechanism-based drugs have been designed and synthesised for treatment of breast cancer. Integration of nucleic acid sequencing studies with mass spectrometry-based peptide sequencing and posttranslational modifications as well as rational drug design will provide a more comprehensive understanding of the pathophysiology of breast cancer and help in evolving therapeutic strategies.

Flavonoids are non-nutritive dietary components that are widely distributed in plants. The present study investigated the antihyperglycaemic and antioxidant effect of rutin, a polyphenolic flavonoid in normal and streptozotocin-induced diabetic Wistar rats. Diabetes as induced in rats by an intraperitoneal injection of streptozotocin. Rutin was orally administered to normal and diabetic rats for a period of 45 days. Fasting plasma glucose, glycosylated haemoglobin, thiobarbituric acid reactive substances and lipid hydroperoxides were significantly (P<0.05) increased, whereas insulin, C-peptide, total haemoglobin, protein levels, non-enzymic antioxidants (glutathione, vitamin C, vitamin E and ceruloplasmin) were decreased significantly (P<0.05) in diabetic rats. Oral administration of rutin to diabetic rats significantly (P<0.05) decreased fasting plasma glucose, glycosylated haemoglobin and increased insulin, C-peptide, haemoglobin and protein levels. Administration of rutin also decreased thiobarbituric acid reactive substances and lipid hydroperoxides and increased the non-enzymic antioxidants significantly (P<0.05). Treatment of normal rats with rutin did not significantly (P<0.05) alter any of the parameters studied. These results show that rutin exhibits antihyperglycaemic and antioxidant activity in streptozotocin-induced diabetic rats.

&lt;p dir="ltr"&gt;Fourier transform infrared (FTIR) spectroscopy has been extensively used in microplastic (MP) pollution research since 2004. The aim of this review is to discuss and highlight the recent advances in FTIR (spectroscopy and chemical imaging) techniques that are used to characterize various polymer types of MPs and to trace their fate and transport in different environmental matrices. More than 400 research papers dealing with FTIR techniques in MP pollution research, which are published between January 2010 and December 2019, have been identified from the Scopus and Web of Science databases. The MPs present in sediment, water (marine and freshwater), biota, air/dust, waste water treatment plants and salt are further classified according to (1) characterization and identification, (2) weathering and aging, (3) ecotoxicology, and (4) analytical methods. The results revealed that the ATR-FTIR technique is mostly used to identify and characterize the MPs found in water and sediment. The µFTIR (FTIR imaging) is extensively used to study the ingestion of MPs in biota (both marine and freshwater). In this article, we have summarized the current knowledge of application of FTIR spectroscopy to MP research and provided insights to future challenges for understanding the risk of MPs.&lt;/p&gt;&lt;h2&gt;Other Information&lt;/h2&gt;&lt;p dir="ltr"&gt;Published in: Critical Reviews in Environmental Science and Technology&lt;br&gt;License: &lt;a href="http://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank"&gt;http://creativecommons.org/licenses/by-nc-nd/4.0/&lt;/a&gt;&lt;br&gt;See article on publisher's website: &lt;a href="https://dx.doi.org/10.1080/10643389.2020.1807450" target="_blank"&gt;https://dx.doi.org/10.1080/10643389.2020.1807450&lt;/a&gt;&lt;/p&gt;

Neurodegenerative diseases affect not only the life quality of aging populations, but also their life spans. All forms of neurodegenerative diseases have a massive impact on the elderly. The major threat of these brain diseases includes progressive loss of memory, Alzheimer's disease (AD), impairments in the movement, Parkinson's disease (PD), and the inability to walk, talk, and think, Huntington's disease (HD). Oxidative stress and mitochondrial dysfunction are highlighted as a central feature of brain degenerative diseases. Oxidative stress, a condition that occurs due to imbalance in oxidant and antioxidant status, has been known to play a vital role in the pathophysiology of neurodegenerative diseases including AD, PD, and HD. A large number of studies have utilized oxidative stress biomarkers to investigate the severity of these neurodegenerative diseases and medications are available, but these only treat the symptoms. In traditional medicine, a large number of medicinal plants have been used to treat the symptoms of these neurodegenerative diseases. Extensive studies scientifically validated the beneficial effect of natural products against neurodegenerative diseases using suitable animal models. This short review focuses the role of oxidative stress in the pathogenesis of AD, PD, and HD and the protective efficacy of natural products against these diseases.

Fatty acids are widely occurring in natural fats and dietary oils and they are known to have antibacterial and antifungal properties. However, little is known on the antibacterial and antifungal properties of the blind-your-eye mangrove (Excoecaria agallocha) and this study for the first time determines the fatty acid composition and the antibacterial and antifungal activities of Fatty Acid Methyl Esters (FAME) of the blind-your-eye mangrove plant found along the coastal areas of south India.

BACKGROUND: Resveratrol is a natural compound suggested to have beneficial health effects. However, people are consuming resveratrol for this reason without having the adequate scientific evidence for its effects in humans. Therefore, scientific valid recommendations concerning the human intake of resveratrol based on available published scientific data are necessary. Such recommendations were formulated after the Resveratrol 2010 conference, held in September 2010 in Helsingør, Denmark. METHODOLOGY: Literature search in databases as PUBMED and ISI Web of Science in combination with manual search was used to answer the following five questions: (1)Can resveratrol be recommended in the prevention or treatment of human diseases?; (2)Are there observed "side effects" caused by the intake of resveratrol in humans?; (3)What is the relevant dose of resveratrol?; (4)What valid data are available regarding an effect in various species of experimental animals?; (5)Which relevant (overall) mechanisms of action of resveratrol have been documented? CONCLUSIONS/SIGNIFICANCE: The overall conclusion is that the published evidence is not sufficiently strong to justify a recommendation for the administration of resveratrol to humans, beyond the dose which can be obtained from dietary sources. On the other hand, animal data are promising in prevention of various cancer types, coronary heart diseases and diabetes which strongly indicate the need for human clinical trials. Finally, we suggest directions for future research in resveratrol regarding its mechanism of action and its safety and toxicology in human subjects.

We present the synthesis and antibacterial activity of silver nanoparticles using Caulerpa racemosa, a marine algae. Fresh C. racemosa was collected from the Gulf of Mannar, Southeast coast of India. The seaweed extract was used for the synthesis of AgNO3 at room temperature. UV–visible spectrometry study revealed surface plasmon resonance at 413 nm. The characterization of silver nanoparticle was carried out using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscope (TEM). FT-IR measurements revealed the possible functional groups responsible for reduction and stabilization of the nanoparticles. X-ray diffraction analysis showed that the particles were crystalline in nature with face-centered cubic geometry.TEM micrograph has shown the formation of silver nanoparticles with the size in the range of 5–25 nm. The synthesized AgNPs have shown the best antibacterial activity against human pathogens such as Staphylococcus aureus and Proteus mirabilis. The above eco-friendly synthesis procedure of AgNPs could be easily scaled up in future for the industrial and therapeutic needs.

Main antioxidants in higher plants include glutathione, ascorbate, tocopherol, proline, betaine, and others, which are also information-rich redox buffers and important redox signaling components that interact with biomembrane-related compartments. As an evolutionary consequence of aerobic life for higher plants, reactive oxygen species (ROS) are formed by partial reduction of molecular oxygen. The above enzymatic and non-enzymatic antioxidants in higher plants can protect their cells from oxidative damage by scavenging ROS. In addition to crucial roles in defense system and as enzyme cofactors, antioxidants influence higher plant growth and development by modifying processes from mitosis and cell elongation to senescence and death. Most importantly, they provide essential information on cellular redox state, and regulate gene expression associated with biotic and abiotic stress responses to optimize defense and survival. An overview of the literature is presented in terms of main antioxidants and redox signaling in plant cells. Special attention is given to ROS and ROS-antioxidant interaction as a metabolic interface for different types of signals derived from metabolism and from the changing environment, which regulates the appropriate induction of acclimation processes or, execution of cell death programs, which are the two essential directions for higher plants.

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

Biosurfactants are surface-active biomolecules produced by microbes (bacteria, fungi, and yeast) and have several advantages over the chemical surfactants, such as lower toxicity, higher biodegradability, better environmental compatibility, higher foaming, high selectivity, and specific activity under extreme conditions such as temperature, pH, and salinity. Almost all the surfactants now available in the market are chemically synthesized. Recently, attention toward the biosurfactants was doubled, which is mainly due to their wide range of functional properties and the diverse synthetic capabilities of the microbes. Microbial biosurfactants are found to have a wide range of applications in environmental protection, which include enhancing oil recovery, controlling oil spills, biodegradation, and detoxification of oil-contaminated industrial effluents and soils. Biosurfactants produced by microorganisms have potential applications in pharmaceutical/medicine, food, cosmetic, pesticide, oil, and biodegradation industries. In this review article, we concentrated on three important aspects such as various types of biosurfactants, the group of microbes involved in the production of biosurfactants, and application of microbial biosurfactants.

The different wt % of Zr-codoped Ag-ZnO catalysts were prepared by the simple precipitation-thermal decomposition method and used for degradation of anionic azo dye Reactive Red 120 (RR 120) under natural sunlight. Highly efficient 4 wt % of Zr-codoped Ag-ZnO was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM) images, field emission scanning electron microscope (FE-SEM) images, energy-dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), and BET surface area measurements. Metal codopants increase the absorbance of ZnO to the entire visible region. XRD and XPS reveal that Ag is in the form of Ag(0) and Zr in the form of Zr(4+). The photocatalytic activity of 4 wt % Zr-codoped Ag-ZnO was compared with other single-metal-doped, undoped, and commercial catalysts. The quantum yields of all processes were determined and analyzed. Zr-Ag-ZnO was found to be more efficient than Ag-ZnO, Zr-ZnO, commercial ZnO, prepared ZnO, TiO(2)-P25, and TiO(2) at neutral pH for mineralization of RR 120 under solar light. To the best of our knowledge, this is the first report on the synthesis of Zr-codoped Ag-ZnO and its use in the degradation of RR 120 dye under natural sunlight illuminatioin. The influences of operational parameters such as the amount of photocatalyst, dye concentration, and initial pH on photomineralization of RR 120 have been analyzed. Mineralization of RR 120 has been confirmed by chemical oxygen demand (COD) measurements. A dual mechanism has been proposed for the higher efficiency of Zr-Ag-ZnO at neutral pH under solar light. This catalyst is found to be reusable.