Fingolimod Rescues Memory and Improves Pathological Hallmarks in the 3xTg-AD Model of Alzheimer’s Disease

Therapeutic strategies for Alzheimer’s disease (AD) have largely focused on the regulation of amyloid pathology while those targeting tau pathology, and inflammatory mechanisms are less explored. In this regard, drugs with multimodal and concurrent targeting of Aβ, tau, and inflammatory processes may offer advantages. Here, we investigate one such candidate drug in the triple transgenic 3xTg-AD mouse model of AD, namely the disease-modifying oral neuroimmunomodulatory therapeutic used in patients with multiple sclerosis, called fingolimod. In this study, administration of fingolimod was initiated after behavioral symptoms are known to emerge, at 6 months of age. Treatment continued to 12 months when behavioral tests were performed and thereafter histological and biochemical analysis was conducted on postmortem tissue. The results demonstrate that fingolimod reverses deficits in spatial working memory at 8 and 12 months of age as measured by novel object location and Morris water maze tests. Inflammation in the brain is alleviated as demonstrated by reduced Iba1-positive and CD3-positive cell number, less ramified microglial morphology, and improved cytokine profile. Finally, treatment with fingolimod was shown to reduce phosphorylated tau and APP levels in the hippocampus and cortex. These results highlight the potential of fingolimod as a multimodal therapeutic for the treatment of AD.

Sesamin inhibits cellular inflammation of microglial cells in the retina and alleviates diabetic retinopathy

Diabetic retinopathy (DR) is the most common micro-vascular complication of diabetes, and the leading cause of vision loss and blindness globally. Due to the unsatisfied outcome of current therapies, a novel strategy needs to be developed. BV2 microglial cells were treated with 25 natural compounds respectively in the stimulation of high glucose (HG), to screen for the potential candidate drug. Streptozotocin (STZ)- induced diabetic mice were injected with different doses of the candidate Sesamin every two days for one month. Then, its protective role and possible mechanism were evaluated. Sesamin was selected as candidate drug due to its inhibition on the secretion of tumor necrosis factor-α (TNFα) in the screen assay. Sesamin also dose-dependently inhibited mRNA levels of HG-induced inflammatory cytokines, including TNFα, interleukin (IL)-1β and IL-6, activated NF-κB signaling pathway, and reduced oxidative stress by decreasing reactive oxygen species levels and increasing antioxidant enzymes in the BV2 and primary retinal microglia. Additionally, Sesamin alleviated brain-retinal barrier breakdown by Evan's blue leakage assay and reduced inflammation in Streptozotocin-induced diabetic mice. In conclusion, Sesamin effectively inhibits HG-induced microglial inflammation in the retina both in vivo and in vitro, suggesting that Sesamin might serve as a candidate drug for DR treatment.

Rubusoside Reduces Blood Glucose and Inhibits Oxidative Stress by Activating the AMPK Signaling Pathway in Type 2 Diabetes Mellitus Mice

The current study aimed at investigating the therapeutic effects of rubusoside on type 2 diabetes mellitus (T2DM) mice models as an alternative hypoglycemic candidate drug. T2DM mice models were established with a combination of streptozotocin (STZ) intraperitoneal injection and high-fat diet. After 10 weeks of rubusoside intragastric administration (100, 200 mg/kg/day) to the mice, the body weight, fasting blood glucose, glucose tolerance, and blood lipids were measured. The liver protein expression levels of p-AMPK, GLUT2, GLUT4 and total antioxidant capacity were also investigated. After 10 weeks of rubusoside administration, the levels of blood glucose and lipids were decreased in T2DM mice. Compared with the model group, rubusoside administration significantly decreased the liver mass-to-body weight ratio, upregulated p-AMPK and GLUT4, and downregulated GLUT2 expression levels in the liver. Activities of superoxide dismutase (SOD), catalase (CAT), and gluathione peroxidase (GSH-Px) were increased, and the concentration of malondialdehyde (MDA) was decreased to reduce oxidative stress in the liver. Liver hematoxylin and eosin (H&E) pathological analysis also showed that rubusoside had a protective effect on T2DM mice liver. These results demonstrate that rubusoside could be used as an anti-diabetic candidate drug, and that its hypoglycemic mechanism might be related to the activation of adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) to modulate the expression of GLUT2 and GLUT4. Finally, rubusoside could also increase total antioxidant capacity to protect the liver from oxidative stress.

Intracellular Drug Targets In Mycobacterium Tuberculosis Revealed By A Chemo-Genetic Approach

Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis, is one of the most devastating infectious agents in the world. It causes chronic lung diseases to one third of the world’s population. Chemo-genetic characterization through in vitro evolution combined with whole genome sequencing analysis can identify novel drug targets and drug resistance genes in Mtb. We performed a genome analysis of 53 Mtb mutants resistant to 15 different hit compounds. We found nonsynonymous mutations/indels in 30 genes that may be associated with drug resistance acquisitions. Beyond confirming previously identified drug resistance mechanisms such as rpoB and lead targets reported in novel anti-tuberculosis drug screenings such as mmpL3, ethA, mbtA, we discovered several unrecognized candidate drug targets including prrB and TB18.5. The exploration of the M. tuberculosis chemical mutant genomes could help novel drug discovery and structural biology of compounds and asscoiated mechanisms of action relevant to tuberculosis treatment.

Antimicrobial and Anti-inflammatory Effects of a Novel Peptide From the Skin of Frog Microhyla pulchra

Brevinins are an important antimicrobial peptide (AMP) family identified in the skin of Ranidae frogs and generally contain a characteristic ranabox structure at their C-terminal sequence. Herein a novel AMP named brevinin-2MP has been identified from the skin of the frog Microhyla pulchra by molecular cloning. Brevinin-2MP (GVITDTLKGVAKTVAAELLRKAHCKLTNSC) with a high amphipathic α-helix in sodium dodecyl sulfate solutions can destroy bacterial cell membrane and kill microbes. Furthermore, brevinin-2MP has been found to inhibit the lipopolysaccharide (LPS)-induced expression of pro-inflammatory NO, MCP-1, IL-6, and TNF-α via binding unidentified targets on the cell membrane and consequently suppressing the activation of MAPK/NF-κB signaling cascades induced by LPS in RAW 264.7 cells. Consistently, brevinin-2MP significantly alleviates the acute inflammatory response in carrageenan-induced mice paw. In conclusion, brevinin-2MP with anti-inflammatory and antimicrobial properties will be an ideal candidate drug molecule for bacterial inflammation treatment.

Anti-asthmatic effect of Ping-Chuan Formula in asthmatic mice, and its molecular mechanism of action

Purpose: To investigate the anti-asthmatic effect of Ping-Chuan Formula (PCF) in a mouse model, and the associated molecular mechanisms.Methods: Asthma mice were induced using ovalbumin (OVA), and PCF (600 mg/kg) was administered to the mice for 4 weeks. Sections of lung tissues were examined microscopically. The expressions of interleukins (ILs), interferon (IFN)-γ, transforming growth factor (TGF)-β were assayed, while lung tissue expressions of Toll like receptor (TLR)-4, GATA binding protein (GATA)-3, Ox40 ligand (OX40L), indoleamine 2,3-dioxygenase (IDO), and forkhead box P3 (Foxp3) determined. The T box expressed in T cells (T-bet) was evaluated using western blotting. The expressions of MHC II and co-stimulators (CD 11c, CD 80 and CD 86) of dendritic cells (DCs) were determined by flow cytometry.Results: PCF decreased inflammation in lung, and also down-regulated IL-4, -6, -17 and TGF-β (p < 0.01), whereas IL-10 and IFN-γ expressions were up-regulated (p < 0.01). Moreover, PCF decreased the expressions of TLR-4, GATA-3 and OX40L in lung tissue, and promoted Foxp3, IDO and T-bet. Besides, PCF decreased the levels of MHC II and co-stimulators (CD 80 and CD 86) on the surface of DCs.Conclusion: PCF exerts anti-asthmatic effect in mice via inhibition of inflammation, and modulation of MHC II and co-stimulators on the surface of DCs. These findings suggest that PCF is a promising candidate drug for treating asthma in humans.

Preclinical Studies into Specific Toxicity of a Candidate Drug Based on Complement C3 neodeterminant Recombinant Humanized Antibody for Treating Traumatic Brain Injuries

This study aims to assess the specific toxicity (allergenicity, immunotoxicity and reproduction toxicity) of a dosage form of complement C3 neodeterminant recombinant humanized antibody. The reactions of general anaphylaxis, active cutaneous anaphylaxis and delayed-type reaction demonstrated no drug-related signs of experimental animal sensitization and immediate or delayed hypersensitivity in the treated animals. It was found that, in doses exceeding significantly the expected human therapeutic dose, the drug has no effect on humoral and cell-mediated immune responses. In addition, the drug does not suppress the phagocytic cell activity thereby indicating the absence of immunotoxic effect. Moreover, the drug has no adverse effects on male and female reproduction, progeny embryonal development, as well as prenatal and postnatal progeny development. The obtained data can be used in future clinical studies of the drug safety.