An effective bio-inspired synthesis of platinum nanoparticles using Caulerpa sertularioides and investigating their antibacterial and antioxidant activities.

In this study, we report the synthesis of platinum nanoparticles (Cs-PtNPs) using an aqueous extract of Caulerpa sertularioides as a reducing agent. Cs-PtNPs were characterized by UV-Vis spectroscopy, fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDAX), high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS) analysis. Cs-PtNPs are spherical with a particle size of 6-22 nm. Cs-PtNPs have been shown to have highly effective antioxidant activities with 74% for DPPH, 63% for reducing power, and 59% for total antioxidant at 1 mg/ml, and results were compared with standard L-ascorbic acid. Furthermore, the Cs-PtNPs demonstrated excellent antibacterial activity against the Gram-negative bacteria, Vibrio parahaemolyticus with the highest zone of inhibition (18 mm) at 50 µg/ml. Moreover, Artemia nauplii showed less toxicity when treated with Cs-PtNPs at 150 µg/ml, indicating that the Cs-PtNPs are less toxic and environment friendly.

Bioengineered gold nanoparticles from marine seaweed Acanthophora spicifera for pharmaceutical uses: antioxidant, antibacterial, and anticancer activities.

In this study, we report a green synthesis of pharmaceutically active gold nanoparticles from marine red alga Acanthophora spicifera by the reduction of chloroauric acid. The formation of A. spicifera-mediated gold nanoparticles (As-AuNPs) was characterized by several analytical techniques. The crystalline and face-centered cubic (fcc) structure were confirmed by X-ray diffraction (XRD) analysis. Electron microscopy results confirmed that As-AuNPs were spherical and the average size of particles was < 20 nm. As-AuNPs hold a significant level of antioxidant activities than A. spicifera extract. As-AuNPs exhibited the highest antibacterial activity against Vibrio harveyi than Staphylococcus aureus at 100 µg/ml. Furthermore, As-AuNPs exhibited the utmost cytotoxicity against human colon adenocarcinoma (HT-29) cells and registered the half-maximal inhibitory concentration (IC50) at 21.86 µg/ml. These findings authenticated that the synthesized As-AuNPs possess a broad spectrum of biological activities, and it can be effectively applied in the field of aquaculture and biomedical application.

Sulfated galactan from Halymenia dilatata enhance the antioxidant properties and prevents Aeromonas hydrophila infection in tilapia fish: In vitro and in vivo study.

The structural characterization and pharmaceutical perspective of sulfated galactan from Halymenia dilatata (Hd-SG) were reported in this study. The Hd-SG consists of carbohydrate (58.5 ± 0.9%), sulfate (28.7 ± 0.9%) and protein (2.7 ± 0.2%). The existence of carbon (28.14%), hydrogen (5.50%), nitrogen (0.51%) and sulfur (8.26%) was confirmed in CHNS analysis. The Hd-SG was mainly comprising of galactose and mannose connected by (1 â†’ 4)-glycosidic linkages, and it shows the molecular weight of 900.9 × 103 g/mol in high-performance size exclusion chromatography (HPSEC). The Hd-SG exhibited the dose depended on antioxidant activities. The in vitro and in vivo studies proved the antibacterial efficacy of Hd-SG against Aeromonas hydrophila. The pre-treated Oreochromis fish with Hd-SG (2.0 g/0.1 kg of feed) showed the highest survival, antioxidant, and improved histological changes than the fish infected with A. hydrophila alone. These results concluded that the isolated Hd-SG has extensive therapeutic properties, and it can be used as preventive medicine.

Isolation and structural characterization of sulfated polysaccharide from Spirulina platensis and its bioactive potential: In vitro antioxidant, antibacterial activity and Zebrafish growth and reproductive performance.

In this study, the sulfated polysaccharide (SPs) was isolated from Spirulina platensis. The isolated SPs contains carbohydrate, sulfate, protein and uronic acid at 38.7 ±â€¯0.30%, 21.3 ±â€¯0.87%, 7.1 ±â€¯0.15% and 7.9 ±â€¯0.4% respectively. The elemental analysis confirmed the presence of carbon (18.01 ±â€¯0.10%), hydrogen (1.83 ±â€¯0.02%) and nitrogen (3.43 ±â€¯0.01%). The monosaccharide composition and molecular weight of SPs were analyzed by high-performance liquid chromatography and size exclusion chromatography respectively. The monosaccharide composition analysis showed the existence of glucose, rhamnose, xylose, fucose, mannose, galactose and the molecular weight of SPs was 1016 kDa. Further, the characterization of SPs was done by UV-visible spectroscopy, X-ray diffraction, FT-IR, 1H NMR and 13C NMR analysis. The obtained SPs exhibited potent antioxidant activity in DPPH (76.45 ±â€¯0.49%), reducing power (absorbance: 1.3 ±â€¯0.02), hydrogen peroxide scavenging (66.3 ±â€¯1.16%), hydroxyl scavenging (68.6 ±â€¯3.2%), nitric oxide (81.36 ±â€¯1.85%) and total antioxidant (absorbance:1.66 ±â€¯0.02) activities at 5 mg/ml. In addition, SPs revealed the highest antibacterial efficacy against the pathogenic bacteria Vibrio vulnificus in disc diffusion, agar bioassay and protein leakage assays at 100 µg/ml. Furthermore, the supplementation of 2% SPs through a feed to the Danio rerio fish enhances the growth and reproductive performances. This finding confirmed that the isolated SPs from S. platensis possess pharmaceutical as well as nutritional properties.

Antibacterial efficacy of a fucoidan fraction (Fu-F2) extracted from Sargassum polycystum.

In this study therapeutic potential of fucoidan fraction-2 (Fu-F2) isolated from Sargassum polycystum was evaluated for the development of antibacterial agent against the human and animal pathogenic bacteria by in vitro and in vivo analysis. The Fu-F2 contained 51.12 ±â€¯0.86% of total sugar and 20.41 ±â€¯0.91% of sulfate. The structural characterization of Fu-F2 was performed by HPLC, FTIR and NMR analysis and reported in our earlier study. The in vitro antibacterial assays such as MIC, MBC, killing kinetics, disk diffusion, protein leakage, ROS and confocal laser scanning microscopy demonstrate that Fu-F2 possesses the highest antibacterial activity against the tested pathogens. Among the tested pathogens, the highest antibacterial activity (21 ±â€¯1.0 mm) was recorded at the concentration of 50 µg/ml against Pseudomonas aeruginosa and the lowest activity (16 ±â€¯0.53 mm) was registered against Staphylococcus aureus. In the in vivo analysis, the pre-treatment group with Fu-F2 at the concentration of 15 mg/0.1 kg through feed exhibited the highest survival (83.4%) and antioxidant activities (p < 0.05) than the fish infected with pathogen. Thus, the present findings suggest that the Fu-F2 of S. polycystum encompasses significant antibacterial properties and that can be used as a therapeutic agent for controlling the bacterial disease.

Investigation of antioxidant and anticancer potential of fucoidan from Sargassum polycystum.

The present study was aimed to evaluate the antioxidant and anticancer potential of fucoidan isolated from Sargassum polycystum. The isolated fucoidan was successfully purified by DEAE cellulose-ion exchange chromatography and dialysis. Totally four active fractions (F1-F4) were collected and explored its chemical constitution by calorimetric assays. Among them, fraction 2 (F2) showed the higher yield percentage, fucose and sulphate content. Further, monosaccharide composition, structural and functional properties of the F2 was analyzed by HPLC, FTIR and NMR. F2 shows highest DPPH radical scavenging activity (55.94 ±â€¯0.69%), reducing power (0.33 absorbance rate), hydrogen peroxide scavenging activity (71.76 ±â€¯2.14%) and nitric oxide radical scavenging activity (51.81 ±â€¯1.04%) at 1000 µg/ml. The cell viability of MCF-7 and HCT-15 cell lines was proportionate to the concentration of F2 with an estimated IC50 was 20 and 50 µg/ml respectively. The fluorescence and confocal laser scanning microscopic analysis demonstrated the apoptotic morphological changes and cell mediated death in F2 treated cancer cells. Higher amount of LDH release was found in the F2 treated cancer cells than the control group. Thus, the present finding proved that the isolated F2 encompasses significant antioxidant and anticancer property.