NobleBlocks

KS Rangasamy College of Arts and Science

UniversityTiruchengode, India

Research output, citation impact, and the most-cited recent papers from KS Rangasamy College of Arts and Science. Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
306
Citations
15.6K
h-index
59
i10-index
374
Also known as
K. S. R. College of Arts and ScienceKS Rangasamy College of Arts and Scienceகே எஸ் ரங்கசாமி கலை மற்றும் அறிவியல் கல்லூரி

Top-cited papers from KS Rangasamy College of Arts and Science

Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens
Ponmurugan Karuppiah, Shyam Kumar Rajaram
2012· Asian Pacific Journal of Tropical Biomedicine241doi:10.1016/s2221-1691(12)60104-x

OBJECTIVE: To evaluate the antibacterial properties of Allium sativum (garlic) cloves and Zingiber officinale (ginger) rhizomes against multi-drug resistant clinical pathogens causing nosocomial infection. METHODS: The cloves of garlic and rhizomes of ginger were extracted with 95% (v/v) ethanol. The ethanolic extracts were subjected to antibacterial sensitivity test against clinical pathogens. RESULTS: Anti-bacterial potentials of the extracts of two crude garlic cloves and ginger rhizomes were tested against five gram negative and two gram positive multi-drug resistant bacteria isolates. All the bacterial isolates were susceptible to crude extracts of both plants extracts. Except Enterobacter sp. and Klebsiella sp., all other isolates were susceptible when subjected to ethanolic extracts of garlic and ginger. The highest inhibition zone was observed with garlic (19.45 mm) against Pseudomonas aeruginosa (P. aeruginosa). The minimal inhibitory concentration was as low as 67.00 µg/mL against P. aeruginosa. CONCLUSIONS: Natural spices of garlic and ginger possess effective anti-bacterial activity against multi-drug clinical pathogens and can be used for prevention of drug resistant microbial diseases and further evaluation is necessary.

Effect of nanosilica and silicon sources on plant growth promoting rhizobacteria, soil nutrients and maize seed germination
Gopalu Karunakaran, Rangaraj Suriyaprabha, Palanisamy Manivasakan, R. Yuvakkumar +3 more
2013· IET Nanobiotechnology210doi:10.1049/iet-nbt.2012.0048

The study was aimed at evaluating the effect of nanosilica and different sources of silicon on soil properties, total bacterial population and maize seed germination. Nanosilica was synthesised using rice husk and characterised. Silica powder was amorphous (50 nm) with >99.9% purity. Sodium silicate treated soil inhibited plant growth promoting rhizobacteria in contrast to nanosilica and other bulk sources. Surface property and effect of soil nutrient content of nanosilica treatment were improved. Colony forming unit (CFU) was doubled in the presence of nanosilica from 4 × 105 CFU (control) to 8 × 105 CFU per gram of soil. The silica and protein content of bacterial biomass clearly showed an increase in uptake of silica with an increase in nanosilica concentration. Nanosilica promoted seed germination percentage (100%) in maize than conventional Si sources. These studies show that nanosilica has favourable effect on beneficial bacterial population and nutrient value of soil.

Application of silica nanoparticles in maize to enhance fungal resistance
Rangaraj Suriyaprabha, Gopalu Karunakaran, Kavitha Kandiah, R. Yuvakkumar +2 more
2013· IET Nanobiotechnology181doi:10.1049/iet-nbt.2013.0004

In this study, maize treated with nanosilica (20-40 nm) is screened for resistance against phytopathogens such as Fusarium oxysporum and Aspergillus niger and compared with that of bulk silica. The resistivity is measured for disease index and expression of plant responsive compounds such as total phenols, phenylalanine ammonia lyase, peroxidase and polyphenol oxidase. The results indicate that nanosilica-treated plant shows a higher expression of phenolic compounds (2056 and 743 mg/ml) and a lower expression of stress-responsive enzymes against both the fungi. Maize expresses more resistance to Aspergillus spp., than Fusarium spp. These results show significantly higher resistance in maize treated with nanosilica than with bulk, especially at 10 and 15 kg/ha. In addition, hydrophobic potential and silica accumulation percentage of nanosilica treated maize (86.18° and 19.14%) are higher than bulk silica treatment. Hence, silica nanoparticles can be used as an alternative potent antifungal agent against phytopathogens.

Biosynthesis of Nanoparticles from Various Biological Sources and Its Biomedical Applications
Gopalu Karunakaran, Kattakgoundar Govindaraj Sudha, Saheb Ali, Eun‐Bum Cho
2023· Molecules163doi:10.3390/molecules28114527

In the last few decades, the broad scope of nanomedicine has played an important role in the global healthcare industry. Biological acquisition methods to obtain nanoparticles (NPs) offer a low-cost, non-toxic, and environmentally friendly approach. This review shows recent data about several methods for procuring nanoparticles and an exhaustive elucidation of biological agents such as plants, algae, bacteria, fungi, actinomycete, and yeast. When compared to the physical, chemical, and biological approaches for obtaining nanoparticles, the biological approach has significant advantages such as non-toxicity and environmental friendliness, which support their significant use in therapeutic applications. The bio-mediated, procured nanoparticles not only help researchers but also manipulate particles to provide health and safety. In addition, we examined the significant biomedical applications of nanoparticles, such as antibacterial, antifungal, antiviral, anti-inflammatory, antidiabetic, antioxidant, and other medical applications. This review highlights the findings of current research on the bio-mediated acquisition of novel NPs and scrutinizes the various methods proposed to describe them. The bio-mediated synthesis of NPs from plant extracts has several advantages, including bioavailability, environmental friendliness, and low cost. Researchers have sequenced the analysis of the biochemical mechanisms and enzyme reactions of bio-mediated acquisition as well as the determination of the bioactive compounds mediated by nanoparticle acquisition. This review is primarily concerned with collating research from researchers from a variety of disciplines that frequently provides new clarifications to serious problems.

Anti‐obesity action of gingerol: effect on lipid profile, insulin, leptin, amylase and lipase in male obese rats induced by a high‐fat diet
Ganapathy Saravanan, P. Ponmurugan, Machampalayam Arumugam Deepa, Balasubramanian Senthilkumar
2014· Journal of the Science of Food and Agriculture158doi:10.1002/jsfa.6642

BACKGROUND: Obesity represents a rapidly growing threat to the health of populations and diet intervention has been proposed as one of the strategies for weight loss. Ginger and its constituents have been used for their anti-flatulent, expectorant and appetising properties and they are reported to possess gastro-protective and cholesterol-lowering properties. The present study investigated the effects of gingerol on the changes in body weight, serum glucose, insulin, insulin resistance and lipid profile in plasma and liver as well as on the activity of amylase, lipase and leptin in high-fat diet (HFD)-induced obese rats. RESULTS: HFD-induced obese rats were treated orally with gingerol (25, 50 and 75 mg kg(-1) ) once daily for 30 days. A lorcaserin-treated group (10 mg kg(-1) ) was included for comparison. The levels of body weight, glucose, lipid profile and insulin, insulin resistance, leptin, amylase and lipase were increased significantly (P < 0.05) in HFD rats. Rats treated with gingerol and fed a HFD showed significantly (P < 0.05) decreased glucose level, body weight, leptin, insulin, amylase, lipase plasma and tissue lipids when compared to normal control. The effect at a dose of 75 mg kg(-1) of gingerol was more pronounced than that of the dose 25 mg kg(-1) and 50 mg kg(-1) . The lorcaserin-treated group also manifested similar effects to those of gingerol. CONCLUSION: These findings suggested that ginger supplementation suppresses obesity induced by a high fat diet and it might be a promising adjuvant therapy for the treatment of obesity and its complications.

Green Synthesis of Magnesium Oxide Nanoparticles by Using Abrus precatorius Bark Extract and Their Photocatalytic, Antioxidant, Antibacterial, and Cytotoxicity Activities
Saheb Ali, Kattakgoundar Govindaraj Sudha, Natesan Thirumalaivasan, Maqusood Ahamed +4 more
2023· Bioengineering145doi:10.3390/bioengineering10030302

The current research is concerned with the synthesis of magnesium oxide (MgO) nanoparticles (NPs) from Abrus precatorius L. bark extract via the green chemistry method. The synthesized MgO NPs was confirmed by using several characterization methods like XRD, FTIR, SEM, TEM, and UV-visible analysis. The synthesized MgO NPs displayed a small particle size along with a specific surface area. Abrus precatorius bark synthesized MgO NPs with a higher ratio of dye degradation, and antioxidant activity showed a higher percentage of free radical scavenging in synthesized MgO NPs. Zebrafish embryos were used as a model organism to assess the toxicity of the obtained MgO nanoparticles, and the results concluded that the MgO NPs were nontoxic. In addition, the anticancer properties of MgO nanoparticles were analyzed by using a human melanoma cancer cell line (A375) via MTT, XTT, NRU, and LDH assessment. MgO NPs treated a human melanoma cancer cell line and resulted in apoptosis and necrosis based on the concentration, which was confirmed through a genotoxicity assay. Moreover, the molecular mechanisms in necrosis and apoptosis were conferred to depict the association of magnesium oxide nanoparticles with the human melanoma cancer cell line. The current study on MgO NPs showed a broad-scope understanding of the use of these nanoparticles as a medicinal drug for melanoma cancer via its physiological mechanism and also a novel route to obtain MgO NPs by using the green chemistry method.

Influence of Nanosilica Powder on the Growth of Maize Crop (<i>Zea Mays</i>L.)
R. Yuvakkumar, Viswanathan Elango, Venkatachalam Rajendran, N. Kannan +1 more
2011· International Journal of Green Nanotechnology108doi:10.1080/19430892.2011.628581

ABSTRACT A novel approach to study the effect of nanosilica on maize crop improvement was proposed. Nanosilica powders were mixed with soil at different concentrations along with control and conventional silica under in vitro and in vivo conditions. In in vitro, the nanosilica increases seed germination (2–11%), water usage efficiency (up to 53%), and total chlorophyll content (13–17%) of maize crop. In in vivo, influence of nanosilica was analyzed on basic parameters such as stem height, stem width, number of leaves, and silica content. The effect of nanosilica on maize crop was found to be enhanced in all aspects. KEYWORDS: nanosilica powdersmaize seed germinationleaf transpirationtotal chlorophyll Acknowledgments We acknowledge the financial support of Defense Research and Development Organization, New Delhi to carry out this project (ERIP/ER/0705076/M/01/1/1016 dt. 11.02.08).

Antibacterial and antioxidant activities of Musa sp. leaf extracts against multidrug resistant clinical pathogens causing nosocomial infection
Ponmurugan Karuppiah, Muhammed Mustaffa
2013· Asian Pacific Journal of Tropical Biomedicine97doi:10.1016/s2221-1691(13)60148-3

OBJECTIVE: To investigate different Musa sp. leave extracts of hexane, ethyl acetate and methanol were evaluated for antibacterial activity against multi-drug resistant pathogens causing nosocomial infection by agar well diffusion method and also antioxidant activities. METHODS: The four different Musa species leaves were extracted with hexane, ethyl acetate and methanol. Antibacterial susceptibility test, minimum inhibitory concentration and minimum inhibitory bacterial concentration were determined by agar well diffusion method. Total phenolic content and in vitro antioxidant activity was determined. RESULTS: All the Musa sp. extracts showed moderate antibacterial activities expect Musa paradisiaca with the inhibition zone ranging from 8.0 to 18.6 mm. Among four species ethyl acetate extracts of Musa paradisiaca showed highest activity against tested pathogens particularly E. coli, P. aeruginosa and Citrobacter sp. The minimum inhibitory concentrations were within the value of 15.63- 250 µg/mL and minimum bactericidal concentrations were ranging from 31.25- 250 µg/mL. Antioxidant activity of Musa acuminate exhibited maximum activity among other three Musa species. CONCLUSIONS: The present study concluded that among the different Musa species, Musa paradisiaca displayed efficient antibacterial activity followed by Musa acuminata against multi-drug resistant nosocomial infection causing pathogens. Further, an extensive study is needed to identify the bioactive compounds, mode of action and toxic effect in vivo of Musa sp.

Foliar Application of Silica Nanoparticles on the Phytochemical Responses of Maize (<i>Zea mays</i> L.) and Its Toxicological Behavior
R. Suriyaprabha, Gopalu Karunakaran, R. Yuvakkumar, V. Rajendran +1 more
2013· Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry92doi:10.1080/15533174.2013.799197

The study aimed to explore the effect of high surface (360.85 m2 g–1) silica nanoparticles (20–40 nm) on phytochemical responses during maize growth in comparison with bulk silica at 15 g L–1. The maize responses are analyzed for the changes in biochemical components. The expression of organic compounds and silica contents favored to nanosilica treatment than bulk and control. In addition, nanosilica is biologically inert against MG-63 cell line till 125 μg mL–1. Soil amendment is found better than foliar application to maize. This helps to improve sustainable farming as an alternative source of silica fertilizer for food crops.

Antibacterial activity of selected medicinal plants against multiple antibiotic resistant uropathogens: a study from Kolli Hills, Tamil Nadu, India
A. Sankaranarayanan, Suresh S. S. Raja, K. Ponmurugan, S. Kandekar +3 more
2011· Beneficial Microbes86doi:10.3920/bm2010.0033

The increasing incidence of antibiotic resistance among bacterial pathogens necessitates medicinal plants as an alternate therapy in restricting the resistant infectious organisms. In this primitive study, the antibiotic resistance of organisms isolated from urinary tract infected patients was evaluated using the National Committee for Clinical Laboratory Standards (NCCLS) method and Multiple Antibiotic Resistance (MAR) index values, and the MAR values was also calculated for plant extracts. The 10 common medicinal plants collected from Kolli hills, Namakkal, south India were extracted using the chloroform, methanol, acetone, ethanol and saponification procedure. The efficacy of the extracts on the uropathogens was tested by agar disc diffusion method in order to analyse the inhibitory activity of plant extract on the organisms. Azadiracta indica A. Juss., Tinospora cordifolia (Wild.) and Euphorbia hirta Linn. exhibited high inhibitory activity against most of the 11 tested organisms followed by Cassia javanica Linn. and Phyllanthus niruri Linn. The maximum zone size of 46.3 mm was exhibited by methanol extract of P. niruri Linn. against Pseudomonas aeruginosa. Asparagus racemosus Willd. and Eupatorium triplinerve Vahl had the least activity against resistant pathogens. Saponified lipids of most of the plants exhibited maximum antibacterial activity. Among the tested organisms, P. aeruginosa and Staphylococcus epidermidis were the most susceptible and Serratia marcescens, Enterobacter cloaceae, Citrobacter koseri, and Citrobacter freundii were the least inhibited by most of the extracts of medicinal plants. It is concluded that revised antibiotic policies and more importantly the development of herbal medicine as an alternative may be incorporated in urological practice.

Effect of silica nanoparticles on microbial biomass and silica availability in maize rhizosphere
S Rangaraj, Gopalu Karunakaran, R. Yuvakkumar, Prabu Periasamy +2 more
2013· Biotechnology and Applied Biochemistry83doi:10.1002/bab.1191

The effect of silica nanoparticles and conventional silica sources on the changes in microbial biomass and silica availability to pure soil and maize rhizosphere was studied. Nanosilica (20-40 nm) was synthesized from rice husk and comprehensively characterized. The efficiency of nanosilica was evaluated in terms of its effects on beneficial microbial population such as phosphate solubilizers, nitrogen fixers, silicate solubilizers, microbial biomass carbon and nitrogen content, and silica content in comparison with other silica sources such as microsilica, sodium silicate, and silicic acid. Nanosilica significantly (P < 0.05) enhanced microbial populations, total biomass content (C = 1508 μg g(-1) and N = 178 μg g(-1) ), and silica content (14.75 mg mL(-1) ). Although microsilica sources enhanced factors associated with soil fertility, their use by maize roots and silicification in soil was found to be less. The results show that nanosilica plays a vital role in influencing soil nutrient content and microbial biota and, hence, may promote the growth of maize crop.

Influence of ZrO <sub>2</sub> , SiO <sub>2</sub> , Al <sub>2</sub> O <sub>3</sub> and TiO <sub>2</sub> nanoparticles on maize seed germination under different growth conditions
Gopalu Karunakaran, Rangaraj Suriyaprabha, Venkatachalam Rajendran, Narayanasamy Kannan
2016· IET Nanobiotechnology74doi:10.1049/iet-nbt.2015.0007

The focus of this investigation is to evaluate the phytotoxicity of selected metal oxide nanoparticles and microparticles as a function of maize seed germination and root elongation under different growth conditions (Petri plate, cotton and soil). The results of seed germination and root elongation experiments reveal that all the growth conditions show almost similar results. Alumina (Al2O3) and titania (TiO2) nanoparticles significantly reduce the germination percentage, whereas silica (SiO2) nanoparticles and microparticles enhance the same. The results of nanoparticles and microparticles of zirconia (ZrO2) are found to be same as those of controls. Root elongation is enhanced by SiO2 nanoparticles and microparticles treatment, whereas inhibition is observed with Al2O3 and TiO2 nanoparticles and microparticles. The X-ray fluorescence spectrometry data of the treated and control seed samples show that seeds uptake SiO2 particles to a greater extent followed by TiO2, Al2O3 and ZrO2. In addition, the uptake of nanoparticles is found to be greater than that of microparticles. Thus, the tested metal oxides penetrated seeds at the nanoscale as compared with the microscale. This study clarifies phytotoxicity of nanoparticles treated in different growth substrates and highlights the impact of nanoparticles on environment and agricultural systems.

Protective effect of chrysin on carbon tetrachloride (CCl <sub>4</sub> )—induced tissue injury in male Wistar rats
Kalaiselvi Velayutham Anand, Ramalingam Anandhi, Murugesan Pakkiyaraj, Pitchairaj Geraldine
2011· Toxicology and Industrial Health67doi:10.1177/0748233711399324

Chrysin, a natural flavonoid has been reported to possess potent anti-inflammatory, anti-cancer and antioxidation properties. In the present study, we aimed to evaluate the putative protective effect of chrysin, an isoflavone, on carbon tetrachloride (CCl(4))-induced toxicity in male Wistar rats. Intraperitoneal administration of CCl(4) (2 ml/kg) to rats for 4 days resulted in significantly elevated (p < 0.05) serum levels of glutamic oxaloacetic transaminase (SGOT), glutamic pyruvate transaminase (SGPT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), when compared to normal rats. In addition, the tissues (liver, kidney and brain) and haemolysate samples showed considerable increase in levels (p < 0.05) of malondialdehyde (MDA) and lowered levels (p < 0.05) of reduced glutathione (GSH), vitamin C and E when compared to values in normal rats. Quantitative analysis of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (Gpx) exhibited lower activities of these antioxidant enzymes in the tissues and haemolysate of CCl(4)-administered rats. The protective action of chrysin on CCl(4)-induced rat was demonstrated with SGPT, SGOT, ALP and LDH resuming to near normal levels, while the mean levels of GSH and of vitamin C and E were elevated, the mean activities of CAT, SOD and Gpx were enhanced and the mean level of MDA was lowered in the tissue and haemolysate samples when compared to the CCl(4)-exposed untreated rats. The expression of the iNOS gene appeared to be up-regulated in the liver and kidney samples of CCl(4)-exposed untreated rats, whereas in CCl(4)-exposed chrysin-treated rats, the mRNA transcript levels of iNOS approximated normal levels. These results strongly suggest that chrysin is able to prevent the oxidative damage induced by CCl(4) in the liver, brain, kidney and haemolysate of male Wistar rats.

Anticancer property of sediment actinomycetes against MCF–7 and MDA–MB–231 cell lines
S. Ravikumar, Mangaladoss Fredimoses, Murugesan Gnanadesigan
2012· Asian Pacific Journal of Tropical Biomedicine61doi:10.1016/s2221-1691(11)60199-8

OBJECTIVE: To investigate the anticancer property of marine sediment actinomycetes against two different breast cancer cell lines. METHODS: In vitro anticancer activity was carried out against breast (MCF-7 and MDA-MB-231) cancer cell lines. Partial sequences of the 16s rRNA gene, phylogenetic tree construction, multiple sequence analysis and secondary structure analysis were also carried out with the actinomycetes isolates. RESULTS: Of the selected five actinomycete isolates, ACT01 and ACT02 showed the IC50 value with (10.13±0.92) and (22.34±5.82) µg/mL concentrations, respectively for MCF-7 cell line at 48 h, but ACT01 showed the minimum (18.54±2.49 µg/mL) level of IC50 value with MDA-MB-231 cell line. Further, the 16s rRNA partial sequences of ACT01, ACT02, ACT03, ACT04 and ACT05 isolates were also deposited in NCBI data bank with the accession numbers of GQ478246, GQ478247, GQ478248, GQ478249 and GQ478250, respectively. The phylogenetic tree analysis showed that, the isolates of ACT02 and ACT03 were represented in group I and III, respectively, but ACT01 and ACT02 were represented in group II. The multiple sequence alignment of the actinomycete isolates showed that, the maximum identical conserved regions were identified with the nucleotide regions of 125 to 221st base pairs, 65 to 119th base pairs and 55, 48 and 31st base pairs. Secondary structure prediction of the 16s rRNA showed that, the maximum free energy was consumed with ACT03 isolate (-45.4 kkal/mol) and the minimum free energy was consumed with ACT04 isolate (-57.6 kkal/mol). CONCLUSIONS: The actinomycete isolates of ACT01 and ACT02 (GQ478246 and GQ478247) which are isolated from sediment sample can be further used as anticancer agents against breast cancer cell lines.

Green synthesis of CdS Quantum dots for photocatalytic and anti-corrosive applications in aqueous media
K. Kandasamy, S. Surendhiran, K.S.G. Jagan, G. Suresh Kumar +2 more
2023· Applied Surface Science Advances57doi:10.1016/j.apsadv.2022.100364

Inorganic pollutants are the leading cause of water pollution, which harms human health and the environment. The most highly efficient nanoparticles with enhanced photocatalytic activity are semiconductor quantum dots (QDs). The heterogeneous photocatalysis using UV radiation on quantum dots is a fascinating technique for treating polluted sewage with a naturally available plant-based product. In this study, CdS QDs were synthesized using a facile green synthetic protocol in the presence of Coccinia grandis (CG) and Punica granatum (PG) fruit sap as capping and stabilizing agents. XRD, HR-TEM, FT-IR, UV-DRS, and photoluminescence spectroscopy were used to analyze the synthesized CdS QDs. The photocatalytic degradation activity of CdS quantum dots was performed against anionic and cationic dyes under UV light irradiation. The results revealed that PG-capped CdS QDs have the best photocatalytic activity compared to CG-capped CdS QDs. Further, the pseudo-first-order model is used to analyze the kinetics studies. Moreover, the electrochemical measurements of pure zinc and CdS QDs coated Zn (Zn/CdS QDs) plate were tested in three electrolytes: sodium chloride, potassium hydroxide, and hydrochloric acid, which demonstrated the corrosion inhibition ability of prepared CdS QDs. The electrochemical impedance spectra, Tafel plot, and in-situ SPM analysis depict the improving corrosion resistance of the Zn metal plate due to the prepared CdS QDs coatings. Based on the results, the prepared CdS QDs by the green method can be a potential candidate in the water purification and corrosion resistance field.

Augmented biocontrol action of silica nanoparticles and Pseudomonas fluorescens bioformulant in maize (Zea mays L.)
S Rangaraj, Gopalu Karunakaran, Prabhu Muthusamy, R. Yuvakkumar +2 more
2014· RSC Advances54doi:10.1039/c3ra46251j

Nanosilica and Pseudomonas sp. was treated in soil to enhance the biocontrol activity against pathogens in maize. The leaf hardness shows an increase in surface roughness and elevated phenols while treating nanobiocomposites. Higher phenols and hardness induce silica accumulation in leaves and initiate more effective physical barriers for crop protection.

Utilization of snail shells to synthesise hydroxyapatite nanorods for orthopedic applications
G. Suresh Kumar, L. Sathish, R. Govindan, E.K. Girija
2015· RSC Advances52doi:10.1039/c5ra04402b

Snail shells have been successfully utilized to synthesize HA nanorods via facile microwave irradiation method in rapid manner using EDTA as a chelating agent.

Ascorbic Acid-Assisted Microwave Synthesis of Mesoporous Ag-Doped Hydroxyapatite Nanorods from Biowaste Seashells for Implant Applications
Gopalu Karunakaran, Eun‐Bum Cho, G. Suresh Kumar, Еvgeny Kolesnikov +4 more
2019· ACS Applied Bio Materials52doi:10.1021/acsabm.9b00239

Post-surgery implant infection is one of the most challenging issues in orthopedics and it is mainly caused by infective micro-organisms. A potential approach to overcome this issue is developing biomaterials with efficient antibacterial activity. The main intention of this present research is devoted to ascorbic acid-assisted microwave synthesis of mesoporous (silver) Ag-doped hydroxyapatite (HAp) nanorods using biowaste seashells with antibacterial properties. XRD, FTIR, and Raman spectroscopy results revealed that the synthesized nanoparticles are hexagonal crystalline HAp. Further, the silver-doped HAp was also successfully produced without affecting the HAp crystalline phase by forming electrostatic interaction with PO43– ions during the synthesis. The morphological features confirm that the pure HAp is elongated mesoporous nanorods with 20 nm width and 300–500 nm length. However, silver doped HAp nanoparticles such as AgHA-1, AgHA-2, and AgHA-3 are found to be similar mesoporous rods but with different aspect ratios in sizes of 15, 10–15, and 5–10 nm width and 80–100, 10–15, and 20–30 nm length. The BET specific surface areas were obtained as 29 ± 3, 84 ± 2, 87 ± 2, and 128 ± 3 m2 g–1, and pore diameters were 4.68, 4.18, 9.30, and 3.77 nm, respectively, for pure HA, AgHA-1, AgHA-2, and AgHA-3. Therefore, HAp nanoparticles with different dimensions and mesoporous structures could be rapidly prepared using a microwave-assisted method and ascorbic acid as a supporting material. In addition, the synthesized HAp nanoparticles are analyzed for its antibacterial and cytotoxicity studies. The antibacterial and cytotoxicity study clearly reveals that the Ag-doped HAp nanorods are efficiently antibacterial and nontoxic in nature. Hence, it is clear that the ascorbic acid-enabled microwave-assisted method will be one of the best methods for the rapid production of HAp nanoparticles with different dimensions and mesoporous structures for its application as an implant material.

Urinary catheter indwelling clinical pathogen biofilm formation, exopolysaccharide characterization and their growth influencing parameters
Kasi Murugan, Selvanayaki Krishnasamy, Saleh Al-Sohaibani
2015· Saudi Journal of Biological Sciences50doi:10.1016/j.sjbs.2015.04.016

Self-reproducing microbial biofilm community mainly involved in the contamination of indwelling medical devices including catheters play a vital role in nosocomial infections. The catheter-associated urinary tract infection (CA-UTI) causative Staphylococcus aureus, Enterobacter faecalis, and Pseudomonas aeruginosa were selectively isolated, their phenotypic as well as genotypic biofilm formation, production and monomeric sugar composition of EPS as well as sugar, salt, pH and temperature influence on their in vitro biofilm formation were determined. From 50 culture positive urinary catheters S. aureus (24%), P. aeruginosa (18%), E. faecalis (14%) and others (44%) were isolated. The performed assays revealed their varying biofilm forming ability. The isolated S. aureus ica, E. faecalis esp, and P. aeruginosa cup A gene sequencing and phylogenetic analysis showed their close branching and genetic relationship. The analyzed sugar, salt, pH, and temperature showed that the degree of CA-UTI isolates biofilm formation is an environmentally sensitive process. EPS monosaccharide HPLC analysis showed the presence of neutral sugars (ng/μl) as follows: glucose (P. aeruginosa: 44.275; E. faecalis: 4.23), lactose (P. aeruginosa: 7.29), mannitol (P. aeruginosa: 2.53; S. aureus: 2.62; E. faecalis: 2.054) and maltose (E. faecalis: 7.0042) revealing species-specific presence and variation. This study may have potential clinical relevance for the easy diagnosis and management of CA-UTI.

Antioxidant, Antibacterial Activities and Identification of Bioactive Compounds from Terminalia chebula Bark Extracts
A. Venkatesan, Arumugam Kathirvel, S. Prakash, V. Sujatha
2016· Free Radicals and Antioxidants46doi:10.5530/fra.2017.1.7

Background: Free radical induces numerous diseases by damaging biomolecules such as lipids, proteins, RNA and DNA. Several scientists reported that numerous plants and plant extracts have potent antioxidant activities to scavenge free radicals. The present study was aimed to screen phytoconstituents, in vitro antioxidant and antibacterial potential in various solvent extracts of Terminalia chebula bark. Methods: Phytochemical analysis, estimation of various metabolites, in vitro antioxidant and antibacterial activity were done by adopting standard protocols. Selected bioactive (acetone) extract of T. chebula was analyzed for their phytochemical profile by GC-MS analysis. Results: The results of preliminary phytochemical screening analysis revealed that presence of various phytochemicals like, alkaloids, flavonoids, glycosides, terpenoids, phenolics, saponins and carbohydrates in most of the tested extracts. Acetone extract possess significant high quantity of both primary and secondary metabolites when compared with other extracts. Remarkable free radicals scavenging potential was observed in acetone extract with lowest IC50 values on all tested radicals namely, DPPH. (IC50=144.77 μg/ml), NO. (IC50=149.46 μg/ml), .OH (IC50=121.18 μg/ml), O2 .- (IC50=159.41 μg/ml), Reducing power (IC50=35.85 μg/ml), Fe2+ ion chelating (IC50=137.56 μg/ml) and TBARS (IC50=201.96 μg/ml). Acetone extract expressed significant high antibacterial activity against S. typhi (15 mm). The result of GC-MS analysis of acetone extract shows the presence of 32 major bioactive compounds, including various phenolic, sesquiterpene, flavonoid, triazine and gibberellin compounds. Conclusion: The present study suggested that T. chebula bark extract serves as a good source of phytochemicals, natural antioxidant and antibacterial agent.