Preparation of alginate oligosaccharide nanoliposomes and an analysis of their inhibitory effects on Caco-2 cells

Supercritical CO2 Extraction of Terpenoids from Indocalamus latifolius Leaves: Optimization, Purification, and Antioxidant Activity

This study aimed to investigate the efficacy of supercritical CO2 (SC-CO2) extraction in enhancing the extraction rate, purity, and antioxidant activity of Indocalamus latifolius (Keng) McClure (Poaceae) leaf terpenoids (ILLTs). Crude extracts obtained from leaves were subjected to qualitative and quantitative analyses, revealing neophytadiene, phytol, β-sitosterol, β-amyrone, squalene, and friedelin as the primary terpenoid constituents, identified through gas chromatography-mass spectrometry (GC-MS). Compared with steam distillation extraction (SD), simultaneous distillation extraction (SDE), ultra-high pressure-assisted n-hexane extraction (UHPE-Hex), ultra-high pressure-assisted ethanol extraction (UHPE-EtOH), ultrasound-assisted n-hexane extraction (UE-Hex), and ultrasound-assisted ethanol extraction (UE-EtOH), SC-CO2 exhibited a superior ILLT extraction rate, purity, and antioxidant activity. Scanning electron microscopy (SEM) observations of the residues further revealed more severe damage to both the residues and their cell walls after SC-CO2 extraction. Under optimal parameters (4.5 h, 26 MPa, 39 °C, and 20% ethyl alcohol), the ILLT extraction rate with SC-CO2 reached 1.44 ± 0.12 mg/g, which was significantly higher than the rates obtained by the other six methods. The subsequent separation and purification using WelFlash C18-l, BUCHI-C18, and Sephadex LH-20 led to an increase in the purity of the six terpenoid components from 12.91% to 93.34%. Furthermore, the ILLTs demonstrated cytotoxicity against HepG2 cells with an IC50 value of 148.93 ± 9.93 μg/mL. Additionally, with increasing concentrations, the ILLTs exhibited an enhanced cellular antioxidant status, as evidenced by reductions in both reactive oxygen species (ROS) and malondialdehyde (MDA) levels.

Preparation, characterization and macrophage-stimulating activity of polyguluronate nanoliposomes

Polyguluronate (PG) consists entirely of α-L-guluronic acid derived from alginate, which is an acidic polysaccharide extracted from brown algae. PG has a short half-life and is easily degraded by microorganisms, resulting in decreased activity and thus its application in the medical field. In this study, polyguluronate liposomes (PGLs) were prepared to improve the macrophage-stimulating activity of PG. The morphology, encapsulation efficiency, particle size distribution, zeta potential and stability of the PGLs were characterized. Results showed that PGLs were uniformly round with an encapsulation efficiency of 77.76 ± 0.89%, a particle size of 63.96 ± 3.98 nm and a zeta potential of -53.4 ± 1.75 mV. The stability studies showed that PGLs should be stored in a neutral environment at 4 °C. The macrophage-stimulating activity of PGLs was better than that of PG. This study provides a promising carrier for the further application of PG in food or medicine.

A Quantitative LC-MS/MS Method for Determination of Liposomal Amphotericin B in Rat Plasma and Tissues and its Application to a Toxicokinetic and Tissue Distribution Study

Background::

Among the existing antifungal drugs, Amphotericin B is the first drug in the treatment of systemic fungal infections. However, its large adverse reactions limit the clinical application and Liposome Amphotericin B resolves the problem.

Objective::

In the present study, a rapid, simple, sensitive and efficient method based on LCMS/ MS for determination of liposomal Amphotericin B in rat plasma and tissue samples using natamycin as the internal standard has been developed and validated.

Methods:

The analytical samples contain the plasma and various tissues disposed of by protein precipitation and determination of liposomal Amphotericin B by an LC-MS/MS. Chromatographic separation was achieved on a Poroshell 120 EC-C18 column (4.6 mm × 50 mm, 2.7 μm) with 10 mmol/L ammonium acetate in water-acetonitrile by gradient elution at a flow rate of 0.7 mL/min. The MS analysis was conducted in positive electrospray ionization with Multiple Reaction Monitoring (MRM).

Results::

The calibration curves of plasma and tissues showed good linear range from 50 to 10000 ng/mL. The analytical samples containing plasma and tissues were stable under different storage conditions and temperature.

Conclusions: :

The developed LC-MS/MS method has been successfully applied to the studies of toxicokinetics and tissue distribution after intravenous injection of liposomal Amphotericin B to rats.