Vitexin and isovitexin are natural flavone C-glucosides that have numerous benefits for human health. However, their low oral bioavailability and poor gastrointestinal absorption dramatically restrict their potential medicinal uses. To overcome this challenge, chitosan-coated alginate microcapsules were prepared for intragastrical administration to rabbits. An LC-MS/MS method was developed and validated for the simultaneous determination of vitexin and isovitexin in the plasma of treated rabbits, using salicylic acid as the internal standard. Raw rabbit plasma samples were deproteinized using acetonitrile as a precipitation agent. Chromatographic separation was performed on a reversed-phase C18 column (100 mm × 4.6 mm, 3.5 µm), with an isocratic mobile solvent system comprising methanol and 0.1% acetic acid (40:60) as the mobile phase. All the analytes and the internal standard were ionized on a triple quadrupole mass spectrometer and electrospray ionization, operating in negative mode and multiple reaction monitoring. The analytical approach developed underwent validation in terms of system suitability, specificity, selectivity, LLOQ of 2 ng/mL, linearity (2.0–200 ng/mL, R² > 0.99), accuracy (the intra- and inter-day from 94 to 110% with the relative standard deviations no more than 8.7%, precision with the recoveries from 97% to 102%, matrix effect (90–100%), carry-over, dilution integrity (2 times), and stability at room and frozen temperature for up to 1 month, and all the parameters met FDA and EMA requirements for bioanalytical methods. The validated procedure was applied to measure the absorption of vitexin and isovitexin from encapsulated extracts in a pilot pharmacokinetic study on rabbit plasma. Compared to the raw traditional extracts, the microcapsules enhanced the bioavailability of vi-texin and isovitexin regarding C_max and AUC values.

Background/Objectives: Vitexin and isovitexin are bioactive flavonoids with promising pharmacological effects; however, they have poor bioavailability. Microencapsulation with biodegradable polymers is a promising strategy for improving their stability, bioavailability, and biocompatibility. This study aimed to optimize the formulation parameters to obtain microspheres with desired properties in terms of size, loading ratio, and vitexin–isovitexin release. Methods: Microspheres were prepared using alginate as the core matrix and a chitosan outer layer. A Design of Experiment approach using response surface methodology was employed. The hypoglycemic effects of the obtained microspheres were evaluated. Results: The formulation using 1.17% low-viscosity alginate, 7.60% calcium chloride, 5.78% Tween 80, and 5.00% Span 80 resulted in microspheres with optimal mean size (10.78 µm), high loading ratio (22.45%) and encapsulation efficiency (68.92%). The in vitro release of vitexin–isovitexin from microspheres was completed within 24 h in controlled manner. The microspheres were found to be non-toxic in vivo and exhibited hypoglycemic effects after 21 days at doses equivalent to 30 and 60 mg/kg of vitexin–isovitexin. The potential mechanisms might involve increasing the size of Islets of Langerhans and improving pancreatic β-cell function and insulin resistance, as observed in alloxan-induced diabetic mice. Conclusions: This work successfully developed alginate–chitosan-based microspheres for the controlled release of vitexin–isovitexin while maintaining their bioactivities.

Background/Objectives: Vitexin and isovitexin are bioactive flavonoids with promising pharmacological effects; however, they have poor bioavailability. Microencapsulation with biodegradable polymers is promising strategy for improving their stability, bioavailability, and biocompatibility. This study aimed to optimize the formulation parameters to obtain microspheres with desired properties in terms of size, loading ratio, and vitexin-isovitexin release. Methods: Microspheres were prepared using alginate as core matrix and a chitosan outer layer. Design of experiments approach using response surface methodology was employed. The hypoglycemic effects of obtained microspheres were evaluated. Results: The formulation using 1.17% low-viscosity alginate, 7.60% calcium chloride, 5.78% Tween 80, and 5.00% Span 80 resulted in microspheres with optimal mean size (10.78 µm), high loading ratio (22.45%) and encapsulation efficiency (68.92%). The in vitro release of vitexin-isovitexin from microspheres was completed within 24 hours in controlled manner. The microspheres were found to be non-toxic in vivo and exhibited hypoglycemic effects after 21 days at doses equivalent to 30 and 60 mg/kg of vitexin-isovitexin. These effects were attributed to increasing in the size of Islets of Langerhans, improving in pancreatic β-cell function and insulin resistance, as observed in alloxan-induced diabetic mices. Conclusions: This work successfully developed alginate-chitosan-based microspheres for the controlled release of vitexin-isovitexin while maintaining their bioactivities.

This study evaluated the anti-inflammatory and analgesic effects of a 95% ethanol extract of Gynura procumbens leaves. These effects were assessed using both in vitro and in vivo models. In vitro anti-inflammatory activity was assessed using the egg white albumin denaturation assay, while in vivo efficacy was evaluated via xylene-induced ear edema and hot plate models in mice at doses of 37.5, 50, and 75 mg/mL. Chemical analysis revealed 22.3 mg essential oil/kg of extract and 22.44 mg quercetin equivalents/g of extract. It inhibited albumin denaturation with an IC50 of 0.34 mg/mL, significantly lower than the IC50 of diclofenac. In the xylene-induced ear edema model, all doses reduced ear thickness, with the 75 mg/mL dose exhibiting an effect comparable to diclofenac. In the hot plate test, the 50 and 75 mg/mL doses significantly increased response latency. These findings demonstrate that the ethanol extract of G. procumbens leaves possesses significant anti-inflammatory and analgesic properties, supporting its potential as a natural therapeutic candidate for inflammation and pain management.

Objectives: Cosmos sulphureus Cav. has a rich history of traditional medicinal use in Southeast Asia, particularly for the treatment of diabetes, high blood pressure, inflammation and infections. This study aimed to optimize flavonoid extraction and evaluate the hypouricemic effects for the gout treatment of the extracts from the flowers of CS. Methods: Extraction optimization was conducted using response surface methodology with a factorial design that included two variables – ethanol concentration (25%–70%) and solvent-to-material ratio (10-20 mL/g) - and three responses: extraction efficiency, total flavonoid content (TFC), and IC _{5 0} values for xanthine oxidase inhibition. Toxicity studies followed the Guidelines for Preclinical and Clinical Trials of Traditional Medicine and Herbal Medicines issued by the Vietnam Ministry of Health as well as the OECD (2001) with minor modifications. The pharmacological activity was assessed in acute and chronic potassium oxonate–induced hyperuricemia models. Results: The optimization CS extraction conditions were identified as percolation using 70% ethanol with a solvent-to-material ratio of 20 mL/g. The extraction process was successfully scaled up to 1 kg of raw material per batch, demonstrating its stability and applicability for further pharmacological studies. Chemical characterization confirmed the extract was rich in flavonoids, with coreopsin and luteolin identified as major constituents. In a model of acute and chronic hyperuricemia induced by potassium oxonate (i.p), the 250 mg/kg CS flower extract demonstrated uric acid-lowering effects similar to the reference drug allopurinol at 10 mg/kg. Conclusions: These findings highlight the novelty of using Cosmos sulphureus Cav. as a potent natural source for anti-hyperuricemic agents, supporting its potential for pharmaceutical development.