Mode of action of kefir supplementary dietary against viral infection.

Microalgae-mediated synthesis of nanoparticles (NPs) is an emerging nanobiotechnology that utilizes the biomolecular corona of microalgae as reducing and capping agents for NP fabrication. This study screened a novel microalgal strain for its potential to synthesize silver (Ag)-NPs and then assayed the biological activities of the NPs. Coelastrella aeroterrestrica strain BA_Chlo4 was isolated, purified, and morphologically and molecularly identified. Chemical composition of the algal extract was determined by GC-MS analysis. Ag-NPs were biosynthesized by C. aeroterrestrica BA_Chlo4 (C@Ag-NPs) and characterized using various techniques. Antiproliferative activity and the biocidal effect of C@Ag-NPs, C. aeroterrestrica algal extract, and chemically synthesized Ag-NPs (Ch@Ag-NPs) were explored, and the scavenging activity of C@Ag-NPs against free radicals was investigated. C@Ag-NPs were hexagonal, with a nanosize diameter of 14.5 ± 0.5 nm and a maximum wavelength at 404.5 nm. FTIR and GC-MS analysis demonstrated that proteins and polysaccharide acted as capping and reducing agents for C@Ag-NPs. X-ray diffraction, energy diffraction X-ray, and mapping confirmed the crystallinity and natural structure of C@Ag-NPs. The hydrodynamic diameter and charge of C@Ag-NPs was 28.5 nm and −33 mV, respectively. C@Ag-NPs showed significant anticancer activity towards malignant cells, with low toxicity against non-cancerous cells. In addition, C@Ag-NPs exhibited greater antioxidant activity and inhibitory effects against Gram-positive and -negative bacteria compared with the other tested treatments. These findings demonstrate, for first time, the potential of a novel strain of C. aeroterrestrica to synthesize Ag-NPs and the potent antioxidant, anticancer, and biocidal activities of these NPs.

Asthma is an inflammatory disease of the lungs, and it causes oxidative stress. Lavandula dentata is an aromatic herb with anti-oxidative and anti-inflammatory activities. This study examined the activity of L. dentata extract on a guinea pig model of asthma. Adult males were divided into five groups: First group was control, second was asthma model induced by OVA, third was treated with L. dentata extract orally (300 mg/kg) for 21 days; the fourth was an asthma model with L. dentata extract (300 mg/kg) and fifth was treated with Tween 80 for 21 days. OVA treatment increased IgE, triglycerides, total cholesterol, glucose levels in serum, WBC count in blood and MDA in lungs. Also, OVA reduced SOD activity, GSH content in lungs, and GGT activity in serum (p<0.05). L. dentata extract treatment in asthma model reduced elevated IgE, triglycerides, total cholesterol, glucose levels in serum, and MDA in lungs (p<0.05), while it increased GSH content in lungs (p<0.05). These results suggest the possibility that L . dentata extract can exert suppressive effects on asthma, and may provide evidence that it is a useful agent for the treatment of allergic airway disease, it also limits oxidative stress induced by OVA. L. dentata extract appears to have hypolipidemic and hypoglycemic activities.

Background: Exposure to pentylenetetrazole (PTZ) is capable of inducing experimental epilepsy in rats. As a result of the use of anticonvulsant treatment, obesity and metabolic syndrome are commonly observed in patients with epilepsy. Prodigiosin (PG) is a red pigment synthesized by bacterial species with important pharmaceutical and biological activities. Here, we investigated the neuroprotective and anticonvulsant activities of silver nanoparticles conjugated with PG (PG-AgNPs) versus pentylenetetrazole (PTZ)-induced epileptic seizures. Methods: Rats were assigned into six experimental groups: control; PG-AgNP (300 mg/kg); PTZ (60 mg/kg, epileptic model); sodium valproate (600 mg/kg) + PTZ; PG-AgNP + PTZ and sodium valproate (VPA)+PG-AgNP+ PTZ. The treatment duration is extended to 7 days. Result: Induction of epilepsy resulted in a significant decrease in monoamines (5-HT, DA, NE), glutamate, aspartate, serine and a significant increase in GABA, glycine and taurine in the brain. In addition, it causes an increase in serum insulin and leptin and a significant decrease in serum glucose and disturbance in oxidative and antioxidant system. Additionally, PG-AgNP enhanced the antioxidant capacity of brain tissue by activating antioxidants and decreasing the levels of pro-oxidants. In addition, it caused decrease in insulin resistant and leptin level in serum accordingly caused increase in the content of blood glucose level which enhance the metabolic rate and minimize the increase in the body weight as a result of anticonvulsant (VPA). Interestingly, PG-AgNP restored the PTZ-induced imbalance between excitatory and inhibitory amino acids and improved monoaminergic and cholinergic transmission.

Cyanobacteria-mediated synthesis of silver nanoparticles (AgNPs) offers a sustainable approach for producing functional AgNPs for biomedical applications. However, controlling their physicochemical properties while maintaining robust biological activities remains a critical challenge. Here, we developed a green, one-pot synthesis method to produce uniform, small AgNPs using the novel Cyanobium gracile PCC 6307 and evaluated their biological activities. PCC 6307 was isolated and identified using microscopic examination and sequencing analysis. The aqueous extract of algal biomass (CB) and cell-free medium (CS) were used to synthesize AgNPs under optimized reaction conditions. Acetyleugenol (38.09%) and eugenol (10.5%) were identified as the predominant metabolites in CB extract by gas chromatography-mass spectrometry. CS@AgNPs and CB@AgNPs showed strong absorption peaks at 412.5 and 430.5 nm and exhibited uniform spherical shapes with core diameters of 4.0 and 12.4 nm, respectively. The synthesized AgNPs exhibited hydrodynamic diameters < 100 nm and negative surface charges. Energy-dispersive X-ray spectroscopy confirmed the elemental composition of AgNPs, while Fourier-transform infrared spectroscopy verified the presence of algal functional groups on their surfaces. AgNPs reduced the colon cancer cell viability to 4.1% at 200 µg/mL exhibiting moderate to low toxicity toward normal human fibroblasts. CS@AgNPs revealed higher biocidal activity (inhibition zone ≤ 20 mm) than CB@AgNPs against Staphylococcus aureus, S. haemolyticus, and S. lentus. The antioxidant activity of AgNPs was assessed using the 2,2-diphenyl-1-picrylhydrazyl assay, where AgNPs showed moderate (46.0%) to low (25.1%) radical scavenging activity. This study provides a sustainable approach for producing uniform, small, and biologically active AgNPs with potential biomedical applications.