Optimization on Preparation Conditions of Salidroside Liposome and Its Immunological Activity on PCV-2 in Mice

Evaluations of the Chuanqi Ophthalmic Microemulsion In Situ Gel on Dry Age-Related Macular Degeneration Treatment

Age-related macular degeneration (AMD) is the third largest eye disease. However, the eye has a variety of drug delivery barriers, which prevent the drug from reaching the lesions in the posterior segment of the eye, coupled with the pathogenesis of dry-AMD; these lead to the lack of effective treatment drugs for dry-AMD. Therefore, the developments of a suitable therapeutic drug and a novel ophthalmic preparation are of great significance for the treatment of dry-AMD. The purposes of this study were to construct a novel traditional Chinese medicine (Chuanqi Fang) anti-AMD microemulsion in situ gel for treating dry-AMD and investigate its characteristic, efficiency, irritation, and tissue distribution. In this study, the characteristic of the Chuanqi microemulsion in situ gel was measured by dynamic light scattering. The electroretinogram (ERG) indicators and the number of retinal pigment epithelial cells were measured to evaluate the therapeutic effect of the novel ophthalmic nanopreparations. Irritation was evaluated according to Technical Guideline Principles (ZGPT4-1). The analysis of tissue distribution was carried out with LC-MS. The research showed that the particle size of microemulsion was 38.56 ± 0.21 nm. The Chuanqi microemulsion in situ gel had certain roles in repairing retina damage of the dry-AMD animal model and showed no irritation. The tissue distribution study found that the microemulsion in situ gel could effectively deliver the drug to the posterior eye of the AMD model rat through the route of cornea-vitreous body-retina. In conclusion, this study provided a meaningful research strategy and research basis for the development of new dry-AMD therapeutic drugs.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

Polyethylenimine-coated PLGA nanoparticles-encapsulated Angelica sinensis polysaccharide as an adjuvant to enhance immune responses

Nanoparticle delivery systems have been widely investigated as new vaccines strategy to enhance the immune responses to antigens against infectious diseases. The positively charged nanoparticles could efficiently improve the immune responses due to targeting and activating the antigen-presenting cells. In this study, the immunopotentiator Angelica sinensis polysaccharide (ASP) was encapsulated into Poly (lactic-co-glycolic acid) (PLGA) nanoparticles, and the polyethylenimine, one of the cationic polymers, was used to coat nanoparticles to develop a new nanoparticle delivery system (ASP-PLGA-PEI) with positively charged. The ASP-PLGA-PEI nanoparticles significantly activated macrophages, and promoted the expression of the MHCII and CD86 and the production of IL-1β and IL-12p70 cytokines of macrophages. Furthermore, the antigen adsorbed on the surface of the ASP-PLGA-PEI nanoparticles enhanced the antigen uptake by macrophages. Moreover, the mice immunized with PCV2 antigen adsorbed ASP-PLGA-PEI nanoparticles significantly enhanced PCV2-specific IgG immune response and the levels of cytokines, induced a mixed Th1/Th2 immune response with Th1 bias compared with other groups. These findings demonstrate that the positively charged nanoparticles (ASP-PLGA-PEI) have the potential to serve as an effective vaccine delivery and adjuvant system to induce vigorous and long-term immune responses.

Salidroside reduces tau hyperphosphorylation via up-regulating GSK-3β phosphorylation in a tau transgenic Drosophila model of Alzheimer's disease

Background

Alzheimer’s disease (AD) is an age-related and progressive neurodegenerative disease that causes substantial public health care burdens. Intensive efforts have been made to find effective and safe treatment against AD. Salidroside (Sal) is the main effective component of Rhodiola rosea L., which has several pharmacological activities.

The objective of this study was to investigate the efficacy of Sal in the treatment of AD transgenic Drosophila and the associated mechanisms.

Methods

We used tau transgenic Drosophila line (TAU) in which tau protein is expressed in the central nervous system and eyes by the Gal4/UAS system. After feeding flies with Sal, the lifespan and locomotor activity were recorded. We further examined the appearance of vacuoles in the mushroom body using immunohistochemistry, and detected the levels of total glycogen synthase kinase 3β (t-GSK-3β), phosphorylated GSK-3β (p-GSK-3β), t-tau and p-tau in the brain by western blot analysis.

Results

Our results showed that the longevity was improved in salidroside-fed Drosophila groups as well as the locomotor activity. We also observed less vacuoles in the mushroom body, upregulated level of p-GSK-3β and downregulated p-tau following Sal treatment.

Conclusion

Our data presented the evidence that Sal was capable of reducing the neurodegeneration in tau transgenic Drosophila and inhibiting neuronal loss. The neuroprotective effects of Sal were associated with its up-regulation of the p-GSK-3β and down-regulation of the p-tau.