Venugopal Sujatha

Spectroscopic and molecular docking studies on the interaction of troxerutin with DNA.

Troxerutin (TXER) is a derivative of naturally occurring bioflavonoid rutin. It possesses different biological activities in rising clinical world. The biological activity possessed by most of the drugs mainly targets on macromolecules. Hence, in the current study we have examined the interaction mechanism of TXER with calf thymus DNA (CT-DNA) by using various spectroscopic methods, isothermal titration calorimetry (ITC) and molecular docking studies. Further, DNA cleavage study was carried out to find the DNA protection activity of TXER. UV-absorption and emission spectroscopy showed low binding constant values via groove binding. Circular dichroism study indicates that TXER does not modify native B-form of DNA, and it retains the native B-conformation. Furthermore, no effective positive potential peak shift was observed in TXER-DNA complex during electrochemical analysis by which it represents an interaction of TXER with DNA through groove binding. Molecular docking study showed thymine guanine based interaction with docking score -7.09 kcal/mol. This result was compared to experimental ITC value. The DNA cleavage study illustrates that TXER does not cause any DNA damage as well as TXER showed DNA protection against hydroxyl radical induced DNA damage. From this study, we conclude that TXER interacts with DNA by fashion of groove binding.

Identification, quantification of bioactive constituents, evaluation of antioxidant and in vivo acute toxicity property from the methanol extract of Vernonia cinerea leaf extract

Context: Vernonia cinerea (L.) Less [Compositae (Asteraceae)] is used traditionally for several medical purposes such as inflammation, pain, fever, and cancer. Objectives: The present study identified the bioactive constituents in the methanol extract of Vernonia cinerea leaf and evaluated its antioxidant activity and acute toxicity. Methods: The identification of phytochemicals was accomplished by GC-MS and the major antioxidant phenolic compounds in the extract were quantified by HPTLC analysis. To quantify the essential elements, atomic absorption spectrophotometeric analysis was carried out. Total phenol and flavonoid content was measured by Folin-Ciocalteau reagent and 2% aluminium chloride, respectively. Results: GC-MS analysis identified the presence of 27 phytoconstituents. The predominant phenolic compound in the extract as quantified by HPTLC was gallic acid (1.92 mg/g) followed by rutin (0.705 mg/g), quercetin (0.173 mg/g), caffeic acid (0.082 mg/g) and ferulic acid (0.033 mg/g). The following elements were quantified: Fe (0.050 ppm), Mn (0.022 ppm), Co (0.0180 ppm), Pb (0.029 ppm), Hg (3.885 ppm) and Se (4.5240 ppm). The antioxidant activity of the extract increased with increasing concentration and the correlation (r2) for all in vitro assays were satisfactory. Conclusions: V. cinerea extract has significant (p < 0.05) antiradical activity. Hence, V. cinerea may have potential medicinal value and can be used in the formulation of pharmacological products for degenerative diseases.

Polyphenol contents and antioxidant activity of Brassica nigra (L.) Koch. leaf extract.

Profound research has been done on the medicinal value of Brassica nigra (BN) seeds, and the leaves of the plant have been investigated in this study. The methanol extracts of the leaves were subjected to several in vitro studies. The antioxidant activity of methanol extract was demonstrated with a wide range of concentration, 10–500 µg mL−1, and the antioxidant activity increased with the increase in concentration. Total phenol content was found to be 171.73 ± 5.043 gallic acid equivalents and the total flavonoid content 7.45 ± 0.0945 quercetin equivalents. Further quantification and identification of the compounds were done by HPTLC and GC–MS analyses. The predominant phenolic compounds determined by HPTLC were gallic acid, followed by quercetin, ferulic acid, caffeic acid and rutin. The free radical quenching property of BN leaf extract suggests the presence of bioactive natural compounds.

Brassica nigra plays a remedy role in hepatic and renal damage

Context: Black mustard [Brassica nigra (L.) Koch] of the Brassicaceae (Cruciferae) family is commonly used as a spice and a cheap source of antimicrobial agents for bacterial infections. Objectives: The present investigation was to demonstrate the protective effect of the methanol extract of B. nigra leaves against d-galactosamine (d-GalN)-induced hepatic and nephrotoxicity in Wistar rats. Methods: Activity of the methanol extract of B. nigra at doses of 200 and 400 mg/kg b.wt. against d-GalN (500 mg/kg b.wt.) induced toxicity, with silymarin used as the standard. Histological damage, activities of serum marker enzyme, hematological changes, metabolites such as bilirubin, urea, uric acid, and creatinine levels, tissue thiobarbutric acid reactive substance, enzymic and non-enzymic antioxidants and inflammatory marker enzymes such as myeloperoxidase, cathepsin D, and acid phosphatase were assessed. Results: The d-GalN-induced toxicity was evident from a significant increase (p < 0.001) in the serum and tissue inflammatory markers in toxic rats, when compared with the control (saline alone treated animals). The B. nigra pretreated groups (200 and 400 mg/kg b.wt.) showed significant (p < 0.001) reduction in the d-GalN-induced toxicity as obvious from biochemical parameters. Histopathological observations confirm the protective effect of B. nigra leaf extract by reduction in hepatic and renal tissue damage. Experimentals extract showed a similar effect as the standard. Conclusions: The crude methanol extract of B. nigra leaf lacks inherent toxicity and exhibits hepatic and nephroprotective effects against d-GalN-induced toxicity in Wistar rats.

Diospyros montana leaf extract-mediated synthesis of selenium nanoparticles and their biological applications

Plant-mediated synthesis of selenium nanoparticles (Se-NPs) was carried out by a simple precipitation method using the aqueous extract of Diospyros montana. The leaf extract was used as a good capping and stabilizing agent and allowed the formation of stable nanoparticles. These Se-NPs were characterized using UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), DLS, zeta potential measurement and elemental analysis by energy-dispersive X-ray spectroscopy (EDX). The FT-IR spectrum confirms the presence of various functional groups in the aqueous leaf extract of Diospyros montana, which may possibly influence the reduction process of the nanoparticles. The XRD data confirmed the formation of crystalline Se-NPs. TEM and DLS analysis determined that the size of the Se-NPs ranges from 4 to 16 nm. The zeta potential obtained was −22.3 mV. The DPPH and the reducing power activity showed the potential antioxidant property of the biosynthesized Se-NPs. The nanoparticle suspension exhibited significant antimicrobial activity against microorganisms such as Gram (+) Staphylococcus aureus, Gram (−) Escherichia coli (bacteria) and Aspergillus niger (fungi). The cytotoxicity of Se-NPs was assayed against human breast-cancer cells (MCF-7). An anticancer property was found in that Se-NPs were able to inhibit the cell growth in a dose-dependent manner.

Selenium nanoparticles synthesized in aqueous extract of Allium sativum perturbs the structural integrity of Calf thymus DNA through intercalation and groove binding

Biomedical application of selenium nanoparticles (SeNPs) demands the eco-friendly composite for synthesis of SeNPs. The present study reports an aqueous extract of Allium sativum (AqEAS) plug-up the current need. Modern spectroscopic, microscopic and gravimetric techniques were employed to characterize the synthesized nanoparticles. Characterization studies revealed the formation of crystalline spherical shaped SeNPs. FTIR spectrum brings out the presence of different functional groups in AqEAS, which influence the SeNPs formation and stabilization. Furthermore the different aspects of the interaction between SeNPs and CT-DNA were scrutinized by various spectroscopic and cyclic voltametric studies. The results reveals the intercalation and groove binding mode of interaction of SeNPs with stacked base pair of CT-DNA. The Stern-Volmer quenching constant (KSV) were found to be 7.02×106M-1 (ethidium bromide), 4.22×106 M-1 (acridine orange) and 7.6×106M-1 (Hoechst) indicating strong binding of SeNPs with CT-DNA. The SeNPs - CT-DNA interactions were directly visualized by atomic force microscopy. The present study unveils the cost effective, innocuous, highly stable SeNPs intricate mechanism of DNA interaction, which will be a milestone in DNA targeted chemotherapy.

Size Dependent Uptake and Hemolytic Effect of Zinc Oxide Nanoparticles on Erythrocytes and Biomedical Potential of ZnO-Ferulic acid Conjugates

Despite zinc oxide nanoparticles (ZnONPs) being increasingly used as carriers in biomedical fields due to their multifaceted properties and therapeutic importance, better understanding of the mechanisms and cellular consequences resulting from their interaction with cells and cellular components has been warranted. In the present study, we investigate the size-dependent interaction of ZnONPs on RBCs, and its impact on cell viability, DNA damage, ROS generation and morphological changes, employing cellular and analytical methods. Size, charge, stability and solubility were confirmed by DLS, zeta potential, ICP-AES and TEM analysis. Further ICP-AES, TEM, spectroscopic observations and cell based assays showed that ZnONPs exhibited a size dependent impact on RBCs and haemoglobin (Hb), particularly size <50 nm. Conversely, ferulic acid (FA) conjugates and serum albumin significantly reduced the adverse effects exhibited by ZnONPs. The extent of DNA damage and ROS generation is comparatively low in ZnONPs-FA than in ZnONPs alone treated cells. Thus our study documents a novel conceptualization delineating the influence of size on the material properties and therapeutic potential of nanoparticle.

Green Synthesis and Biological Applications of Silver Nanoparticles Using Phyllanthus maderaspatensis L. Root Extract

Abstract Biosynthesis of metal nanoparticles is a raising research area because of their vital role in nanomedicines. In the present work, we have synthesized silver nanoparticles (AgNPs) using the aqueous extract of Phyllanthus maderaspatensis L. root. AgNPs are characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), XRD – X-ray powder diffraction spectroscopy (XRD), and Energy dispersive X-ray spectroscopy (EDS) techniques. The synthesized AgNPs were also evaluated for its antioxidant, antibacterial, and cytotoxicity activities. The result indicates that the phytoconstituents present in the P. maderaspatensis root extract were mostly accountable for the reduction of Ag+ ions. UV spectrum was observed at 479 nm to the formation of AgNPs. Bioactive compounds were identified by FT-IR. The presence of elements was characterized by EDS. The morphology and size of the AgNPs were determined by SEM, HR-TEM, and X-ray diffraction analysis which showed the average particle size ranging from 3–14 nm. It was more effective against micro-organisms and also, AgNPs might serve as a potent antioxidant as revealed by DPPH and superoxide assays. Furthermore, these AgNPs also showed a potent cytotoxic activity against MCF-7 breast cancer cell lines. Herein, we suggested the green synthesis of AgNPs with potent antibacterial, antioxidant, and cytotoxic activities with feasible biomedical and industrial applications.

Green Biosynthesis of AgNPs using Albizia saman Leaf Aqueous Extract and their Biological Applications

Abstract Now days, nanotechnology has emerged as an simple division of current science and untied novel epoch in the fields of material science and receiving the worldwide attention due to its ample applications. The silver nanoparticles (AgNPs) have attracted with considerable interest as a result of their extensive applicability in different research fields such as chemistry, energy, medicine, and catalysis. In the present investigation, we have described a cost effective and eco-friendly technique for the synthesized AgNPs was completed using the aqueous extract of Albizia saman leaf and silver nitrate (1 mM) as a reducing property and also used as a capping agent. AgNPs were characterized using the spectral studies via, UV, FT-IR, XRD, EDX, and HR-SEM analysis. AgNPs were found the size ranging from 30 to 60 nm. AgNPs were also analyzed by ELISA testing method. A silver nanoparticle at different concentrations was evaluated for its antibacterial effect, against various pathogens. The MIC value (minimum inhibitory concentration) was increased with increasing concentration of AgNPs. Photocatalytic study of these synthesized AgNPs was evaluated using methylene blue as an organic dye, under sunlight irradiation and these nanoparticles showed the higher efficiency in degrading the dye within a few minutes of exposure. Further, biosynthesized nanoparticles also exhibited more significant cytotoxic effect on anticancer cell lines (MCF-7). Moreover, the biosynthesized AgNPs offer copious benefits of eco-friendly and compatibility for pharmaceutical, as well as studies on different biological activities in various fields should be strengthened in future.