Leptospiral cell wall hydrolase (LIC_10271) binding peptidoglycan, lipopolysaccharide, and laminin and the protein show LysM and M23 domains are co-existing in pathogenic species.

Leptospirosis, a global reemerging zoonosis caused by the spirochete Leptospira, has severe human and veterinary implications. Cell wall hydrolase (LIC_10271) with LytM (peptidase M23) and LysM domains are found to be associated with various pathogenic bacteria. These domains regulate effects on extracellular matrix and biofilm components, which promote cell wall remodeling and pathogen dissemination in the host. In this study, we present the cloning, expression, purification, and characterization of LIC_10271. To determine the localization of LIC_10271 within the inner membrane of Leptospira, Triton X-114 subcellular fractionation and immunoblot studies were performed. Furthermore, r-LIC_10271 binds with peptidoglycan, lipopolysaccharide, and laminin in a dose-dependent manner. Analysis of the signal peptide, M23, and LysM domains revealed conservation primarily within the P1 group of Leptospira, which encompasses the most pathogenic species. Moreover, the presence of native-LIC_10271 in the inner membrane and the distribution of M23 and LysM domains across pathogenic strains indicates their potential involvement in the interaction between the host and Leptospira.

Leptospiral imelysin (LIC_10713) is secretory, immunogenic and binds to laminin, fibronectin, and collagen IV.

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira. Early and accurate diagnosis is the prime step in managing the disease. Secretory proteins of Leptospira remain distinguished for diagnosis due to their availability as soluble proteins in the serum and their interaction with the host immune response due to their extracellular presence. This study presents the cloning, expression, purification, and characterization of imelysin or LruB (LIC_10713), a putative leptospiral protein. We report that the localization of imelysin showed its presence in the inner membrane and in the culture supernatant. The imelysin was upregulated under in vitro physiological conditions of infection. The LIC_10713 interacted significantly with laminin, fibronectin, collagen type I, and collagen type IV in a dose-dependent manner. Phylogenetic analysis showed that LIC_10713 is predominately found in the pathogenic species of Leptospira, and the GxHxxE motif of imelysin-like proteins is represented as the amino acid sequence GWHAIE. Also, immunoglobulins in leptospirosis-infected patients recognize recombinant-LIC_10713 with 100% specificity and 90.9% sensitivity. The secretion nature, abundance, upregulation, binding to ECM components, and immunogenicity determine LIC_10713 as an important molecule that can be used as an anti-leptospirosis measure. KEY POINTS: • The imelysin-like protein (LIC_10713) of Leptospira is a secretory protein • The protein LIC_10713 can bind ECM molecules • The LIC_10713 is mainly found in pathogenic leptospires • The anti-LIC_10713 antibody from human serum can detect the r-LIC_10713.

Peeping into Mitochondrial Diversity of Andaman Goats: Unveils Possibility of Maritime Transport with Diversified Geographic Signaling.

Andaman and Nicobar Islands, a part of South-East Asia, is enriched with the presence of native breeds of livestock (cattle, pig, goat) and poultry. There are two native goat breeds, viz., Andaman local goat and Teressa goat in Andaman and Nicobar Islands. However, to date, the origin and genetic makeup of these two breeds have not been detailed. Therefore, the present study describes the genetic makeup of Andaman goats through analysis of mitochondrial D-loop sequence for sequence polymorphism, phylogeographical signaling and population expansion events. The genetic diversity of the Teressa goat was less compared to the Andaman local goat due to its sole presence on Teressa Island. Out of 38 well-defined haplotypes of Andaman goats, the majority of haplotypes belonged to haplogroup A followed by haplogroup B and haplogroup D. The result of mismatch distribution and neutrality tests indicated no population expansion event of haplogroup A and B. Finally, based on poor geographical signaling, we hypothesize that Andaman goats have been imported to these Islands either through multidirectional diffusion or unidirectional diffusion. We justify our hypothesis of multidirectional diffusion on the basis of observation of the haplotype and nucleotide diversity of Andaman goats. Simultaneously, the probability of unidirectional diffusion of goats in these islands from the Indian subcontinent in different spells of domestication events through maritime routes cannot be ignored.

Supplementing turmeric rhizome powder in growing Andaman local pigs: a conflated approach for therapy evaluation.

This paper examined the pluripotent effect of supplementation of turmeric rhizome powder (TRP) (Curcuma longa) in growing Andaman local pigs. A total of 48 pigs were randomly allotted into four groups and fed diets containing TRP at 4 concentrations, that is, 0 (control group), 0.05 (treatment 1), 0.1 (treatment 2), and 0.2% (treatment 3) for 30 days. The mean body weight of pigs supplemented with 0.1% and 0.2% TRP was significantly higher than that of the control group (41.66 ± 0.44, 42.59 ± 0.33 vs 40.38 ± 0.30 kg; p ≤ 0.05) which indicated the effect of TRP as growth enhancer. A significant (p ≤ 0.05) decrease in serum concentration of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) was recorded in supplemented groups as compared to the control group. Creatinine kinase (U/l) decreased in all the treatment groups as compared to the control group. Total cholesterol, triglyceride, and low-density lipoprotein cholesterol decreased significantly after supplementation with 0.1% and 0.2% TRP in comparison to the control group. However, there was marked increase in high-density lipoprotein cholesterol (mg/dl) in all TRP-supplemented groups than the control group (27.67 ± 0.60 in T1, 32.76 ± 0.32 in T2, and 34.58 ± 0.37 in T3 vs. 23.73 ± 0.69 in control; p ≤ 0.05). Further, there was increase in antioxidant profile after TRP supplementation. Anti-inflammatory potentiality of TRP could also be appreciated since TRP supplementation downregulated (p ≤ 0.05) expression of IL-6, IL-1ß, and IFN-γ. Therefore, we perceive that this conflated approach is an example of its own kind to focus on modification of health status of pigs for more productivity and augmentation of immune response.

Maternal lineage of Nicobari pig (Sus scrofa nicobaricus) correlated with migration of Nicobarese, a native tribal population of Andaman and Nicobar Islands, India.

Nicobari pig is reared by Nicobarese, a native tribal population of Andaman and Nicobar Islands. Nicobari pig has maintained its genetic identity due to geographical isolation. This communication is the first report on maternal inheritance of Nicobari pigs. DNA polymorphism data showed seven haplotypes. D-loop sequence information and mitogenome analysis were able to earmark Nicobari pigs to Asian clade. The domestication process of pigs and its expansion pattern help to understand human migration pattern. Based on this hypothesis, this communication elucidates the probable origin of Nicobarese. Earlier studies indicated that Nicobarese had genetic affinities to races distributed in China, Malaysia and Thailand. Our data on maternal inheritance of Nicobari pig correlates with the data on migration of Nicobarese. Moreover, we could establish a novel connection of Nicobarese with people of Northeastern parts of India, Philippines and Vietnam through phylogenetic signal and geographical provenance of Nicobari pig. We further concluded that migration of Nicobarese happened during Western route of migration (WRM) ∼4000 years before present. Therefore, we propose one wave hypothesis of peopling of Nicobar based on our study and existence of Ausrtroasiatic language, Mon-Khmer in these islands.

Legacies of domestication, Neolithic diffusion and trade between Indian subcontinent and Island Southeast Asia shape maternal genetic diversity of Andaman cattle.

Andaman cattle is a precious indigenous livestock species endemic to Andaman and Nicobar Islands, India. Till date, origin and genetic makeup of the breed which is warranted for breed conservation is not known. Moreover, the spread of zebu cattle from Indus valley to different parts of Island Southeast Asia (ISEA) is not properly understood. Here, we report the genetic diversity, population structure of Andaman cattle and their evolution in the context of epicentre of zebu domestication and ISEA. High genetic diversity in complete mitochondrial D-loop sequences indicated the ability of the breed to withstand impending climate change. Total 81 haplotypes were detected and all of them except three belonged to Bos indicus. The presence of taurine haplotypes in Andaman cattle indicate introgression by European-derived cattle. A poor phylogenetic signal of Andaman cattle with genetic affinities with cattle of Indian subcontinent and ISEA was observed. The poor phylogenetic structure may be due to multidirectional gene flow from Indian subcontinent and ISEA, with which Andaman shares a close cultural and trade relationship from Neolithic age. We hypothesize that Andaman cattle is the outcome of Neolithic diffusion from centre of zebu domestication along with multidirectional commercial exchange between Indian subcontinent and ISEA.

Molecular characterization of Rhipicephalus microplus in Andaman and Nicobar Islands, India: an insight into genetic assemblages.

The tick, Rhipicephalus microplus is considered as the most notorious ectoparasite of veterinary importance in tropical and sub-tropical regions of the world. The present study deals with the molecular characterization of R. microplus in different regions of Andaman and Nicobar Islands using sequence information of mitochondrial cytochrome C oxidase subunit I (COX1) and their phylogenetic relationship with other Indian R. microplus genotypes. DNA polymorphism study identified a total of eight haplotypes with haplotype diversity of 0.909 ± 0.065 and nucleotide diversity of 0.01911 ± 0.00493. Currently, R. microplus complex consists of five taxa; R. microplus clade A sensu Burger et al. (2014), R. microplus clade B sensu Burger et al. (2014), R. microplus clade C sensu Low et al. (2015), R. australis and R. annulatus. Phylogenetic analysis revealed the presence of two clades (clade A and clade C) of R. microplus in Andaman and Nicobar isolates; Nicobar isolates belonged to clade A whereas Andaman isolates belonged to clade C of R. microplus complex. All the other Indian sequences retrieved from GenBank belonged to clade C of R. microplus complex. Andaman isolates under clade C of R. microplus were phylogenetically distinct from Indian isolates, which indicates independent speciation under isolated island milieu. In Indian isolates, no host-specific or geographical location-specific sub-clustering was observed which indicates the species jumping potential of the R. microplus tick. Therefore, this study indicated the presence of two different genetic makeup of R. microplus complex in two areas of the Andaman and Nicobar archipelago separated by a natural geographical barrier. This indicates presence of two different founding populations of ticks, one in the south and north-middle Andaman and the other in Nicobar Island.

Genetic structure, population diversity and ancestry of Nicobari fowl based on mtDNA complete D-loop sequences.

Nicobari fowl constitute an endemic poultry germplasm of Andaman and Nicobar Islands, India. Genetic diversity, population structure and ancestry of Nicobari fowl were analysed with mitochondrial D-loop sequences. Analysis of complete D-loop sequences (1231-1232 bp) showed 46 polymorphic sites resulting in 26 haplotypes with overall haplotype diversity of 0.895 and nucleotide diversity of 0.0064. Analysis of molecular variance of spatial populations (sampling sites) of Nicobari fowl revealed that the estimated FST value as 0.229 among the populations. Tajima's D and Fu's FS tests indicated nonsignificant deviation from neutrality and the multimodal pattern of mismatch distribution in demographic expansion suggested that Nicobari fowl populations are in equilibrium. The median-joining (MJ) network of D-loop sequences with reference haplogroup sequences identifies the presence of haplogroups A, B, E1, E2, F and I in Nicobari fowl. The major haplogroup in Nicobari fowl was E (60%), which is otherwise found mainly in the Indian subcontinent. Phylogenetic analysis of Nicobari fowl with junglefowl by maximum likelihood method showed Gallus gallus murghi and G. g. spadiceus as maternal progenitors. Grouping of Nicobari fowl with their primary ancestor, Indian red Junglefowl (G. g. murghi) and the presence of Indian subcontinent-specific haplogroups (E2 and I) support the independent domestication of chickens in India. This study will help to design breeding strategy for conservation of Nicobari fowl in its island habitat.

Deducing Insulin-Producing Cells from Goat Adipose Tissue-Derived Mesenchymal Stem Cells.

Mesenchymal stem cell is a potent tool for regenerative medicine against control of incurable diseases in human and animals. Diabetes mellitus is one such condition marked with the blood glucose is high due to lack of insulin (INS) hormone secreted by the pancreatic cells. Rare, but sporadic, cases of dysfunctional pancreatic cells in goat as well as the promises of stem cell therapy as an off-the-shelf medicine prompted us to explore the potential of adipose-derived goat mesenchymal stem cells (AD-MSCs) to transdifferentiate into pancreatic islet-like cells. We isolated, in vitro cultured, and characterized the AD-MSCs by expression of MSC-specific markers and differentiation into multiple mesodermal lineage cells. The characterized AD-MSCs were in vitro transdifferentiated into INS-producing islet-like cells using a cocktail of glucose, nicotinamide, activin-A, exendin-4, pentagastrin, retinoic acid, and mercaptoethanol in 3 weeks. The transdifferentiated islet-like cells demonstrated the expression of pancreatic endoderm-specific transcripts PDX1, NGN3, PAX6, PAX4, ISL1, and GLUT2 as well as protein expression of pancreatic and duodenal homeobox 1 (PDX1), INS, and Islets 1 (ISL1). The islet-like cells also demonstrated the significant glucose-dependent INS release with respect to the course of transdifferentiation regime. The study envisaged to create the building material for basic research into mechanism of glucose homeostasis, which may pave road for developments in diabetes drug discovery and regenerative therapies.

Physiological and immune responses to long road transportation in Andaman local pigs.

Transportation of farm animals is a routine management practice. During transportation, animals experience physiological and psychological stress which has negative consequences on health and welfare of animals. Effect of transportation on pig health and welfare in island ecosystem is not properly known. Here, we report the effect of transportation stress under island ecosystem on serum biochemical parameters, lipid profile, stress biomarkers, and immune parameters in Andaman local pig. Twelve pigs were transported from North and Middle Andaman to South Andaman via road in which two small sea channels have to be crossed in ferry with vehicle on board. Transportation triggered increase in serum levels of total protein and albumin. Elevated levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, and creatine kinase in transported pigs indicated muscular exercise or impaired liver function. Transportation induced dyslipidemia indicated by elevated levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides and a decreased level of high-density lipoprotein cholesterol. High level of serum total nitric oxide and serum MDA as well as low antioxidant capacity in transported pigs indicated oxidative stress induction. Transportation resulted in activation of stress response and increased levels of serum cortisol and heat shock proteins were recorded in transported pigs. Moreover, increased concentration of pro-inflammatory cytokines (IL-2, IL-6, IL-12, IL-1ß, and IFN-γ) and decreased concentration of anti-inflammatory cytokine IL-4 were detected in transported pigs. The results of the study are helpful for better understanding of transportation stress in pigs under island ecosystem.

Tri-Model Therapy: Combining Macrocyclic Lactone, Piperazine Derivative and Herbal Preparation in Treating Humpsore in Cattle.

Stephanofilariasis or humpsore is a chronic parasitic dermatitis of cattle. Various treatment regimens were attempted in the past but were found to be partially effective. Here, we claim a successful treatment regime using an FDA-approved macrocyclic lactone, a piperazine derivative, and an herbal preparation. Twenty-four cattle (18 affected and 6 unaffected) were selected and divided into Gr 1: positive control (infected without treatment; n = 6), Gr 2: treatment group (infected with treatment with ivermectin; n = 6), Gr 3: treatment group (infected with treatment with tri-model therapy including ivermectin, diethylcarbamazine citrate, and an herbal ointment, n = 6), and Gr 4: negative control (non-infected animals; n = 6). In Gr 2 and Gr 3, treatment to the ailing animals were given for 30 days. Lesion was significantly reduced in day 15 of post-treatment and completely healed on day 30 of post-treatment in Gr 3. Tri-model therapy recorded significant improvement in the surface area of the sore as compared to ivermectin administration alone. Antioxidants were increased and malondialdehyde (MDA) and cortisol concentrations were decreased significantly (p < 0.05) in Gr 3 than in untreated control group at day 14, 21 and 28. Histopathological changes in infected animals were characterized by parakeratotic hyperkeratosis along with presence of nucleated keratinocytes. There were infiltrations of polymorphonuclear cells specially eosinophils along with a few monomorphonuclear cells. Microfilarial organism was observed beneath the epidermis, which was surrounded by fibrocytes and infiltrated cells. In the tri-model-treated animal after recovery, the skin revived a normal architecture. Therefore, tri-model therapy has the potential to cure humpsore.

Origin, genetic diversity and evolution of Andaman local duck, a native duck germplasm of an insular region of India.

Domestic ducks are of paramount importance as a cheap source of protein in rural India. Andaman local duck (ALD) is an indigenous avian genetic resource of Andaman and Nicobar islands (ANI) and is mainly distributed in Middle and Northern parts of these islands. Negligence has brought this breed on the edge of extinction necessitating immediate conservation efforts. Here, we report the genetic diversity, population structure and matrilineal genetic root of ALD. Partial mtDNA D-loop sequences were analyzed in 71 ALD samples and analysis revealed 19 polymorphic sites and 13 haplotypes. Estimated haplotype (Hd ± SD) and nucleotide diversity (π ± SD) were 0.881 ± 0.017 and 0.00897 ± 0.00078 respectively. The high genetic diversity of ALD indicates introgression of genetic material from other local duck breeds. In addition, it can be postulated that ALD bearing high genetic diversity has strong ability to adapt to environmental changes and can withstand impending climate change. Phylogenetic and network analysis indicate that ALD falls under Eurasian clade of mallard and ALD forms three clusters; one cluster is phylogenetically close to Southeast Asian countries, one close to Southern part of mainland India and the third one forms an independent cluster. Therefore, ALD might have migrated either from Southeast Asian countries which enjoy a close cultural bondage with ANI from time immemorial or from Southern part of India. The independent cluster may have evolved locally in these islands and natural selection pressure imposed by environmental conditions might be the driving force for evaluation of these duck haplotypes; which mimics Darwin's theory of natural selection. The results of the study will be beneficial for formulating future breeding programme and conservation strategy towards sustainable development of the duck breed.

Host-Parasite Interaction in Sarcoptes scabiei Infestation in Porcine Model with a Preliminary Note on Its Genetic Lineage from India.

The burrowing mite Sarcoptes scabiei causes scabies in humans or mange in animals. It infests a wide range of mammalian species including livestock, companion animals, wild animals, and humans. Differential diagnosis of Sarcoptes varieties is key for epidemiological studies and for formulation of an eradication program. Host-parasite interaction at the systemic level is very important to understand the pathogenicity of the mite. This communication deals with the preliminary report on the genetic characterization of S. scabiei from India. Moreover, the effect of S. scabiei infestation on host physiology with special emphasis on serum biochemical parameters, lipid profile, oxidant/antioxidant balance, stress parameters, and immune responses were evaluated in a porcine model. Cytochrome C oxidase 1 and voltage-sensitive sodium channel based phylogenetic study could distinguish human and animals isolates but could not distinguish host or geographical specific isolates belonging to animal origin. An absence of host-specific cluster among animal isolates argues against the hypothesis of delineating S. scabiei as per host origin. Elevated levels of markers of liver function such as albumin, AST, ALT, ALP, and LDH in infested animals indicated impaired liver function in infested animals. S. scabiei infestation induced atherogenic dyslipidemia indicated by elevated levels of total cholesterol, low-density lipoprotein cholesterol and triglycerides, and a decreased level of high-density lipoprotein cholesterol. Oxidative stress in infested animals was indicated by a high level of nitric oxide and serum MDA as oxidative stress markers and low antioxidant capacity. S. scabiei triggered stress response and elevated levels of serum cortisol and heat shock proteins were recorded in infested animals. S. scabiei infestation increased the serum concentration of immunoglobulins and was associated with up-regulation of IL-2, IFN-γ, IL-1ß, and IL-4 indicating both Th1 and Th2 response. The results of the study will be helpful for a better understanding of host-parasite interaction at the systemic level in crusted scabies in pigs.

A Promising Proton Conducting Electrolyte BaZr1-xHoxO3-δ (0.05 ≤ x ≤ 0.20) Ceramics for Intermediate Temperature Solid Oxide Fuel Cells.

In this study, the Ho-substituted BaZrO3 electrolyte ceramics (BaZr1-xHoxO3-δ, 0.05 ≤ x ≤ 0.20) were synthesized through a low-cost flash pyrolysis process followed by conventional sintering. The effects of Ho-substitution in BaZrO3 studied in terms of the structural phase relationship, microstructure and electrical conductivity to substantiate augmented total electrical conductivity for intermediate temperature solid oxide fuel cells (IT-SOFCs). The Rietveld refined X-ray diffraction (XRD) patterns revealed that pure phase with [Formula: see text] space group symmetry of cubic crystal system as originated in all samples sintered at 1600 °C for 8 h. The Raman spectroscopic investigations also approved that Ho incorporation in BaZrO3 ceramics. Field Emission Scanning Microscopic (FESEM) study informed a mixture of fine and coarse grains in the fracture surface of Ho-substituted BaZrO3 sintered samples. The relative density and average grain size of samples were observed to decrease as per the addition of Ho-substitution in BaZrO3 ceramics. The electrical conductivity study was accomplished by Electrical Impedance Spectroscopy (EIS) under 3% humidified O2 atmosphere from 300 to 800 °C. Furthermore, the total electrical conductivity of BaZr0.8Ho0.2O3-δ ceramic was found to be 5.8 × 10-3 S-cm-1 at 600 °C under 3% humidified atmosphere, which may be a promising electrolyte for IT-SOFCs.

Complete mitogenome sequencing of Andaman buffalo: an endangered germplasm of Andaman and Nicobar Islands, India.

Andaman buffalo is an indigenous buffalo of Andaman and Nicobar Islands, India. Over the last decade, it has witnessed a rapid decline in population, necessitating its immediate characterization and conservation. The present study reports the complete mitogenome profile of Andaman buffalo which is 16,359 bp in length and comprised of 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs and two ribosomal RNAs. In addition, one A + T rich region (D-loop) was also present. A biasness towards A and T base was observed in all the genes. All the PCGs except ND6 were present on heavy strand. Start codons for all the 13 PCGs were ATN codon and abbreviated/truncated stop codons were observed in ND1, ND2, COX3, ND3 and ND4. The phylogenetic analysis revealed that the Andaman buffalo is closely related to buffalo from India and China. The results from this study will help in sketching the conservation plan of the threatened breed.

A Natural Quinazoline Derivative from Marine Sponge Hyrtios erectus Induces Apoptosis of Breast Cancer Cells via ROS Production and Intrinsic or Extrinsic Apoptosis Pathways.

Here, we report the therapeutic potential of a natural quinazoline derivative (2-chloro-6-phenyl-8H-quinazolino[4,3-b]quinazolin-8-one) isolated from marine sponge Hyrtios erectus against human breast cancer. The cytotoxicity of the compound was investigated on a human breast carcinoma cell line (MCF-7). Antiproliferative activity of the compound was estimated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MTT assay showed significant inhibition of MCF-7 cells viability with the IC50 value of 13.04 ± 1.03 µg/mL after 48 h. The compound induced down-regulation of anti-apoptotic Bcl-2 protein and increase in the pro-apoptotic Bax/Bcl-2 ratio in MCF-7 cells. The compound activated the expression of Caspases-9 and stimulated downstream signal transducer Caspase-7. In addition, Caspase-8 showed remarkable up-regulation in MCF-7 cells treated with the compound. Moreover, the compound was found to promote oxidative stress in MCF-7 cells that led to cell death. In conclusion, the compound could induce apoptosis of breast carcinoma cells via a mechanism that involves ROS production and either extrinsic or intrinsic apoptosis pathways. The systemic toxic potential of the compound was evaluated in an in vivo mouse model, and it was found non-toxic to the major organs.

Mitochondrial landscape of indigenous pig germplasm of Andaman and Nicobar Islands.

Nicobari pig and Andaman Desi pig are indigenous pig germplasm of Andaman and Nicobar islands, India. Over the last two decades, the pig breeds witnessed a rapid decline in population, necessitating immediate characterization and conservation. The present study depicts the complete mitochondrial genome sequence of Nicobari pig and Andaman Desi pig. The mitogenomes of both the breeds encode 37 genes including 13 protein coding genes, 22 tRNAs, and two ribosomal RNA genes. In addition, a control region (D-loop) was also present. Phylogenetic analysis showed that Nicobari is phylogenetically close to Banna mini and Breed I pig, whereas Andaman Desi pig is close to Mong cai and Jinhua pig breeds. The results of the study will be helpful for formulating of conservation strategy of the native swine breeds.

Silk scaffolds in bone tissue engineering: An overview.

Bone tissue plays multiple roles in our day-to-day functionality. The frequency of accidental bone damage and disorder is increasing worldwide. Moreover, as the world population continues to grow, the percentage of the elderly population continues to grow, which results in an increased number of bone degenerative diseases. This increased elderly population pushes the need for artificial bone implants that specifically employ biocompatible materials. A vast body of literature is available on the use of silk in bone tissue engineering. The current work presents an overview of this literature from materials and fabrication perspective. As silk is an easy-to-process biopolymer; this allows silk-based biomaterials to be molded into diverse forms and architectures, which further affects the degradability. This makes silk-based scaffolds suitable for treating a variety of bone reconstruction and regeneration objectives. Silk surfaces offer active sites that aid the mineralization and/or bonding of bioactive molecules that facilitate bone regeneration. Silk has also been blended with a variety of polymers and minerals to enhance its advantageous properties or introduce new ones. Several successful works, both in vitro and in vivo, have been reported using silk-based scaffolds to regenerate bone tissues or other parts of the skeletal system such as cartilage and ligament. A growing trend is observed toward the use of mineralized and nanofibrous scaffolds along with the development of technology that allows to control scaffold architecture, its biodegradability and the sustained releasing property of scaffolds. Further development of silk-based scaffolds for bone tissue engineering, taking them up to and beyond the stage of human trials, is hoped to be achieved in the near future through a cross-disciplinary coalition of tissue engineers, material scientists and manufacturing engineers. STATEMENT OF SIGNIFICANCE: The state-of-art of silk biomaterials in bone tissue engineering, covering their wide applications as cell scaffolding matrices to micro-nano carriers for delivering bone growth factors and therapeutic molecules to diseased or damaged sites to facilitate bone regeneration, is emphasized here. The review rationalizes that the choice of silk protein as a biomaterial is not only because of its natural polymeric nature, mechanical robustness, flexibility and wide range of cell compatibility but also because of its ability to template the growth of hydroxyapatite, the chief inorganic component of bone mineral matrix, resulting in improved osteointegration. The discussion extends to the role of inorganic ions such as Si and Ca as matrix components in combination with silk to influence bone regrowth. The effect of ions or growth factor-loaded vehicle incorporation into regenerative matrix, nanotopography is also considered.

Effect of different mineralization processes on in vitro and in vivo bone regeneration and osteoblast-macrophage cross-talk in co-culture system using dual growth factor mediated non-mulberry silk fibroin grafted poly (Є-caprolactone) nanofibrous scaffold.

This study evaluates mineralized nanofibrous polymeric scaffolds at supporting in vitro osteogenic differentiation of human mesenchymal stem cells (hMSCs) and in vivo bone tissue regeneration. Co-electrospin, alternative soaking, and electrodeposition were used to introduce hydroxyapatite in non-mulberry silk fibroin grafted poly(Є-caprolactone) nanofibrous scaffolds. Bone morphogenic protein-2 and Transforming growth factor-ß, at a potency ratio of 1:1, are covalently coupled onto the scaffolds. hMSCs proliferation and interactions are studied through MTT and Alamar blue assay and scanning electron and confocal microscopy. Alkaline phosphatase activity, mineralization assays, and real-time PCR studies substantiate hMSCs' osteogenic differentiation. Co-cultures of human macrophages and osteoblasts exhibit insignificant pro-inflammatory cytokines production. In vivo trials are conducted in rabbit femur (distal metaphysis region). Bone regeneration ability of the scaffolds' is assessed using chronological radiography, micro-CT analysis, host tissue immuno-compatibility, histology, scanning electron microscope imagery, and fluorochrome labelling. In vitro and in vivo characterizations for osteogenesis and osseointegration show best results for scaffolds mineralized by electrodeposition, followed by alternate soaking and co-electrospinning. Non-mulberry silk fibroin grafted poly(Є-caprolactone) nanofibrous scaffold, mineralized by electrodeposition, could provide promising platform for bone healing and regeneration.

Inhibition of Oxidative Stress and Enhancement of Cellular Activity by Mushroom Lectins in Arsenic Induced Carcinogenesis.

Chronic arsenicosis is a major environmental health hazard throughout the world, including India. Animals and human beings are affected due to drinking of arsenic contaminated ground water, due to natural mineral deposits, arsenical pesticides or improperly disposed arsenical chemicals. Arsenic causes cancer with production of free radicals and reactive oxygen species (ROS) that are neutralized by an elaborate antioxidant defense system consisting of enzymes and numerous non-enzymatic antioxidants. Dietary antioxidant supplements are useful to counteract the carcinogenesis effects of arsenic. Oyster mushroom lectins can be regarded as ingredients of popular foods with biopharmaceutical properties. A variety of compounds have been isolated from mushrooms, which include polysaccharides and polysaccharopeptides with immune-enhancing effects. Lectins are beneficial in reducing arsenic toxicity due to anticarcinogenetic roles and may have therapeutic application in people suffering from chronic exposure to arsenic from natural sources, a global problem that is especially relevant to millions of people on the Indian subcontinent.