Polychaeta-mediated synthesis of gold nanoparticles: A potential antibacterial agent against Acute Hepatopancreatic Necrosis Disease (AHPND)-causing bacteria, Vibrio parahaemolyticus.

Gold nanoparticles (AuNPs) have emerged as a promising application in aquaculture. Their nano-sized dimensions, comparable to pathogens offer potential solutions for combating antibiotic resistance. In this study, AuNPs were synthesized by using polychaetes, Marphysa moribidii as the bio-reducing agent. Modifications were made to reduce agglomeration in green-synthesized AuNPs through ultrasonication. The antibacterial activities of AuNPs against V. parahaemolyticus were evaluated. The physicochemical characteristics of the green synthesized AuNPs were comprehensively investigated. The successful formation of AuNPs was confirmed by the appearance of a red ruby colour and the presence of surface Plasmon resonance (SPR) absorption peaks at 530 nm as observed from UV-vis spectroscopy. Scanning electron microscopy (SEM) revealed spherical-shaped AuNPs with some agglomerations. Transmission electron microscopy (TEM) showed particle size of AuNPs ranging from 10 nm to 60 nm, meanwhile dynamic light scattering (DLS) analysis indicated an average particle size of 24.36 nm. X-ray diffraction (XRD) analysis confirmed the high crystallinity of AuNPs, and no AuNPs were detected in the polychaetes extracts prior to synthesis. A brief ultrasonication significantly reduced the tendencies for AuNPs to coalesce. The green-synthesized AuNPs demonstrated a remarkable antibacterial efficacy against V. parahaemolyticus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests revealed that a concentration of 0.3 g/ml of AuNPs effectively inhibited V. parahaemolyticus. These findings highlighted the potential of green-synthesized AuNPs as antibacterial agents for the prevention and management of AHPND in aquaculture.

Photoprotective Potential, Cytotoxicity, and UPLC-QTOF/MS Analysis on Bioactive Solvent Fractions of Moringa concanensis Nimmo Bark.

Moringa concanensis Nimmo (Moringaceae) belongs to the same family of M. oleifera (miracle tree) and is a medicinal plant traditionally used by Indians to treat various ailments related to diabetes, tumours, inflammation, and blood pressure. Despite its versatility, the photoprotective properties of the plant remain unclear. This study revealed the UV-protective properties of its methanol bark extract and respective subfractions, chloroform, hexane, and ethyl acetate through total phenolic and flavonoid content (TPC & TFC), antioxidant (DPPH), sun protecting factor (SPF) value, and UV absorption spectra analysis. This study also investigated on the inhibitory effect of the tested samples on collagenases and elastase, which are well-known for their role in the skin. The cytotoxic and H2O2 scavenging properties of M. concanensis in 3T3-L1 cells were explored. Finally, the phytochemical profiling of the active fraction was conducted through UPLC-QTOF/MS analysis. Among the tested fractions, the chloroform fraction of M. concanensis showed the highest TPC (30.92 ± 0.71 mg GAE/DW), TFC (29.05 ± 0.09 mg QE/DW), and antioxidant properties (IC50-6.616 ± 1.90 µgml-1). Additionally, chloroform fraction demonstrated the highest SPF value, 10.46 at 200 µgml-1, compared to the other tested fractions. All the fractions showed a broad absorption spectrum covering both UVA and UVB ranges. The chloroform fraction of M. concanensis also showed collagenase (50%) and elastase (IC50-2.95 ± 1.23 µgml-1) inhibition properties similar to the positive control. Cytotoxic results revealed that the chloroform fraction of M. concanensis prevented the H2O2-induced oxidative damage in 3T3-L1 cells even at lower concentrations (1.56 µgml-1). UPLC-QTOF/MS analysis tentatively identified the presence of bioactive flavonoids and phenolics such as astragalin, quercetin, isoquercetin, and caffeic acid in the active fraction of M. concanensis bark. Overall, it is suggested that the chloroform fraction of M. concanensis bark has the potency to be used as an active ingredient in sunscreen products.

Gellan Gum Hydrogels Filled Edible Oil Microemulsion for Biomedical Materials: Phase Diagram, Mechanical Behavior, and In Vivo Studies.

The demand for wound care products, especially advanced and active wound care products is huge. In this study, gellan gum (GG) and virgin coconut oil (VCO) were utilized to develop microemulsion-based hydrogel for wound dressing materials. A ternary phase diagram was constructed to obtain an optimized ratio of VCO, water, and surfactant to produce VCO microemulsion. The VCO microemulsion was incorporated into gellan gum (GG) hydrogel (GVCO) and their chemical interaction, mechanical performance, physical properties, and thermal behavior were examined. The stress-at-break (σ) and Young's modulus (YM) of GVCO hydrogel films were increased along with thermal behavior with the inclusion of VCO microemulsion. The swelling degree of GVCO hydrogel decreased as the VCO microemulsion increased and the water vapor transmission rate of GVCO hydrogels was comparable to commercial dressing in the range of 332-391 g m-2 d-1. The qualitative antibacterial activities do not show any inhibition against Gram-negative (Escherichia coli and Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. In vivo studies on Sprague-Dawley rats show the wound contraction of GVCO hydrogel is best (95 ± 2%) after the 14th day compared to a commercial dressing of Smith and Nephew Opsite post-op waterproof dressing, and this result is supported by the ultrasound images of wound skin and histological evaluation of the wound. The findings suggest that GVCO hydrogel has the potential to be developed as a biomedical material.

Four-Week Consumption of Malaysian Honey Reduces Excess Weight Gain and Improves Obesity-Related Parameters in High Fat Diet Induced Obese Rats.

Many studies revealed the potential of honey consumption in controlling obesity. However, no study has been conducted using Malaysian honey. In this study, we investigated the efficacy of two local Malaysian honey types: Gelam and Acacia honey in reducing excess weight gain and other parameters related to obesity. The quality of both honey types was determined through physicochemical analysis and contents of phenolic and flavonoid. Male Sprague-Dawley rats were induced to become obese using high fat diet (HFD) prior to introduction with/without honey or orlistat for four weeks. Significant reductions in excess weight gain and adiposity index were observed in rats fed with Gelam honey compared to HFD rats. Moreover, levels of plasma glucose, triglycerides, and cholesterol, plasma leptin and resistin, liver enzymes, renal function test, and relative organ weight in Gelam and Acacia honey treated groups were reduced significantly when compared to rats fed with HFD only. Similar results were also displayed in rats treated with orlistat, but with hepatotoxicity effects. In conclusion, consumption of honey can be used to control obesity by regulating lipid metabolism and appears to be more effective than orlistat.

Corrigendum to "Stevioside from Stevia rebaudiana Bertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes".

[This corrects the article DOI: 10.1155/2013/938081.].

Tinospora crispa Ameliorates Insulin Resistance Induced by High Fat Diet in Wistar Rats.

The antidiabetic properties of Tinospora crispa, a local herb that has been used in traditional Malay medicine and rich in antioxidant, were explored based on obesity-linked insulin resistance condition. Male Wistar rats were randomly divided into four groups, namely, the normal control (NC) which received standard rodent diet, the high fat diet (HFD) which received high fat diet only, the high fat diet treated with T. crispa (HFDTC), and the high fat diet treated with orlistat (HFDO). After sixteen weeks of treatment, blood and organs were harvested for analyses. Results showed that T. crispa significantly (p < 0.05) reduced the body weight (41.14 ± 1.40%), adiposity index serum levels (4.910 ± 0.80%), aspartate aminotransferase (AST: 161 ± 4.71 U/L), alanine aminotransferase (ALT: 100.95 ± 3.10 U/L), total cholesterol (TC: 18.55 ± 0.26 mmol/L), triglycerides (TG: 3.70 ± 0.11 mmol/L), blood glucose (8.50 ± 0.30 mmo/L), resistin (0.74 ± 0.20 ng/mL), and leptin (17.428 ± 1.50 ng/mL) hormones in HFDTC group. The insulin (1.65 ± 0.07 pg/mL) and C-peptide (136.48 pmol/L) hormones were slightly decreased but within normal range. The histological results showed unharmed and intact liver tissues in HFDTC group. As a conclusion, T. crispa ameliorates insulin resistance-associated with obesity in Wistar rats fed with high fat diet.