PG545 treatment reduces RRV-induced elevations of AST, ALT with secondary lymphoid organ alterations in C57BL/6 mice

Anti-allergic effects of Asarum heterotropoides on an ovalbumin-induced allergic rhinitis murine model

Allergic rhinitis (AR) is a common chronic respiratory disease. Asarum heterotropoides (AH) is predicted to be a treatment for allergic diseases, but its therapeutic effect is unclear. We aimed to determine the anti-allergic effects of AH in mice with ovalbumin (OVA)-induced AR. OVA-induced AR mouse model was constructed, and AH was orally administered for a week; next, nasal clinical symptoms were evaluated. The levels of serum histamine, OVA-specific IgE, and IL-13 were measured by ELISA. Inflammatory cells, including leukocytes, neutrophils, eosinophils, and macrophages were counted in the nasal lavage fluid (NALF). Histopathological examinations of the nasal tissues were performed using H&E, Giemsa, and PAS staining. The production of periostin and eotaxin-3 from AH-treated human nasal epithelial cells (HNEpCs) in vitro, was measured using ELISA. Oral administration of AH alleviated allergic symptoms in mice with AR; significantly decreased levels of allergic mediators, such as serum histamine and OVA-specific IgE. The decrease in allergic symptoms positively correlated with the decrease in serum allergic mediators. The NALF of AH-treated AR mice demonstrated lower number of eosinophils. AH demonstrated a capacity to reduce the infiltration of mast cells, eosinophils, and goblet cells, thereby resulting in thinner nasal tissues. Moreover, treatment of HNEpCs with AH demonstrated suppressed production of periostin and eotaxin-3. AH exerts a therapeutic effect in modulating AR through multi-target and multi-function influence on regulating B cells, mast cells, eosinophils, goblet cells, and epithelial cells.

Phlorizin exerts potent effects against aging induced by D-galactose in mice and PC12 cells

Phlorizin is the main active ingredient of apple peel and has potential utilization value. Some recent studies have suggested that phlorizin may have antioxidant capacity and protect the liver. The injection of a low dose of d-galactose can cause some changes that resemble accelerated aging in mice. This study explored the protective effects of phlorizin on d-galactose-induced mice and PC12 cells. In this study, ICR mice were divided into a normal group (NOR), a d-galactose model group (d-gal) and phlorizin treatment groups (100 mg kg-1, 200 mg kg-1 and 400 mg kg-1). In addition to the NOR group, four other groups were injected with d-galactose (120 mg kg-1) for 12 weeks. The results showed that phlorizin reduced the decline of strength, coordination and spatial memory caused by aging, increased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), increased total antioxidant capacity (T-AOC), and reduced the content of malondialdehyde (MDA). On the other hand, phlorizin increased the levels of interleukin-2 (IL-2) and acetylcholine (ACh), reduced the release of interleukin-6 (IL-6), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and decreased the activity of acetylcholinesterase (AChE) in the brain, improved the expression of antioxidant genes related to the nuclear factor E2-related factor 2 (Nrf2) pathway, and reduced the occurrence of morphological lesions in the hippocampus and liver. In addition, phlorizin improved cell viability and reduced the cytotoxicity of d-galactose-induced oxidative stress in PC12 cells. Meanwhile, the protective effect of phlorizin was abolished in Nrf2 gene knockdown PC12 cells. Furthermore, molecular docking showed that phlorizin could bind Keap1 protein, which can interact with Nrf2 protein. Therefore, these results suggest that phlorizin may delay senescence and enhance antioxidant capacity through the Nrf2 pathway.

Chikungunya Virus Strains from Each Genetic Clade Bind Sulfated Glycosaminoglycans as Attachment Factors

Alphavirus infections are a global health threat, contributing to outbreaks of disease in many parts of the world. Recent epidemics caused by CHIKV, an arthritogenic alphavirus, resulted in more than 8.5 million cases as the virus has spread into new geographic regions, including the Western Hemisphere. CHIKV causes disease in the majority of people infected, leading to severe and debilitating arthritis. Despite the severity of CHIKV disease, there are no licensed therapeutics. Since attachment factors and receptors are determinants of viral tropism and pathogenesis, understanding these virus-host interactions can enhance our knowledge of CHIKV infection. We analyzed over 670 glycans and identified GAGs as the main glycan bound by CHIKV. We defined specific GAG components required for CHIKV binding and assessed strain-specific differences in GAG binding capacity. These studies provide insight about cell surface molecules that CHIKV binds, which could facilitate the development of antiviral therapeutics targeting the CHIKV attachment step.

Chikungunya virus (CHIKV) is an arthritogenic alphavirus that causes debilitating musculoskeletal disease. CHIKV displays broad cell, tissue, and species tropism, which may correlate with the attachment factors and entry receptors used by the virus. Cell surface glycosaminoglycans (GAGs) have been identified as CHIKV attachment factors. However, the specific types of GAGs and potentially other glycans to which CHIKV binds and whether there are strain-specific differences in GAG binding are not fully understood. To identify the types of glycans bound by CHIKV, we conducted glycan microarray analyses and discovered that CHIKV preferentially binds GAGs. Microarray results also indicate that sulfate groups on GAGs are essential for CHIKV binding and that CHIKV binds most strongly to longer GAG chains of heparin and heparan sulfate. To determine whether GAG binding capacity varies among CHIKV strains, a representative strain from each genetic clade was tested. While all strains directly bound to heparin and chondroitin sulfate in enzyme-linked immunosorbent assays (ELISAs) and depended on heparan sulfate for efficient cell binding and infection, we observed some variation by strain. Enzymatic removal of cell surface GAGs and genetic ablation that diminishes GAG expression reduced CHIKV binding and infectivity of all strains. Collectively, these data demonstrate that GAGs are the preferred glycan bound by CHIKV, enhance our understanding of the specific GAG moieties required for CHIKV binding, define strain differences in GAG engagement, and provide further evidence for a critical function of GAGs in CHIKV cell attachment and infection.

IMPORTANCE Alphavirus infections are a global health threat, contributing to outbreaks of disease in many parts of the world. Recent epidemics caused by CHIKV, an arthritogenic alphavirus, resulted in more than 8.5 million cases as the virus has spread into new geographic regions, including the Western Hemisphere. CHIKV causes disease in the majority of people infected, leading to severe and debilitating arthritis. Despite the severity of CHIKV disease, there are no licensed therapeutics. Since attachment factors and receptors are determinants of viral tropism and pathogenesis, understanding these virus-host interactions can enhance our knowledge of CHIKV infection. We analyzed over 670 glycans and identified GAGs as the main glycan bound by CHIKV. We defined specific GAG components required for CHIKV binding and assessed strain-specific differences in GAG binding capacity. These studies provide insight about cell surface molecules that CHIKV binds, which could facilitate the development of antiviral therapeutics targeting the CHIKV attachment step.