Ruthenium(II)–arene complexes with chelating quinoline ligands as anti-amyloid agents

Recent recognition of the soluble form of the amyloid-beta (Aβ) peptide as a neurotoxic agent in Alzheimer’s disease (AD) has spurred the development of agents to target this species. Because Aβ is known to chelate metal ions in solution, metal-based therapeutics are uniquely suited to exploit this affinity, where coordination to Aβ has been shown to impact the neurotoxicity of the peptide. Ruthenium(II)–arene complexes are unique candidates for evaluation, as one face of the molecule is blocked by the hydrophobic arene ring, while coordination to the Aβ peptide can occur on the other side of the molecule. We have prepared and evaluated two Ru(II)–arene complexes with chelating quinoline-based ligands, Ru1 and Ru2, for their respective anti-amyloid abilities. Although both complexes decreased the aggregation of soluble Aβ, Ru1 displayed promise in disrupting formed aggregates of the peptide. These findings represent an exciting new avenue for therapeutic development in AD, where both sides of the aggregation equilibrium are affected.

Anemarrhenae asphodeloides rhizoma Extract Enriched in Mangiferin Protects PC12 Cells against a Neurotoxic Agent-3-Nitropropionic Acid

The rhizome of Anemarrhena asphodeloides Bunge, used in Traditional Chinese Medicine as a brain function-improving herb, is a promising source of neuroprotective substances. The aim of this study was to evaluate the protective action of xanthones from A. asphodeloides rhizomes on the PC12 cell line exposed to the neurotoxic agent—3-nitropropionic acid (3-NP). The xanthone-enriched fraction of the ethanolic extract of A. asphodeloides (abbreviated from now on as XF, for the Xanthone Fraction), rich in polyphenolic xanthone glycosides, in concentrations from 5 to 100 μg/mL, and 3-NP in concentrations from 2.5 to 15 mM, were examined. After 8, 16, 24, 48, and 72 h of exposure of cells to various combinations of 3-NP and XF, the MTT viability assay was performed and morphological changes were estimated by confocal fluorescence microscopy. The obtained results showed a significant increase in the number of cells surviving after treatment with XF with exposure to neurotoxic 3-NP and decreased morphological changes in PC12 cells in a dose and time dependent manner. The most effective protective action was observed when PC12 cells were pre-incubated with the XF. This effect may contribute to the traditional indications of this herb for neurological and cognitive complaints. However, a significant cytotoxicity observed at higher XF concentrations (over 10 µg/mL) and longer incubation time (48 h) requires caution in future research and thorough investigation into potential adverse effects.

Melatonin Attenuates Oxidative Damage Induced by Acrylamide In Vitro and In Vivo

Acrylamide (ACR) has been classified as a neurotoxic agent in animals and humans. Melatonin (MT) has been shown to be potentially effective in preventing oxidative stress related neurodegenerative disorders. In this study, whether MT exerted a protective effect against ACR-induced oxidative damage was investigated. Results in cells showed that reactive oxygen species (ROS) and malondialdehyde (MDA) significantly increased after ACR treatment for 24 h. MT preconditioning or cotreatment with ACR reduced ROS and MDA products, whereas the inhibitory effect of MT on oxidant generation was attenuated by blocking the MT receptor. Increased DNA fragmentation caused by ACR was significantly decreased by MT coadministration. In vivo, rats at 40 mg/kg/day ACR by gavage for 12 days showed weight loss and gait abnormality, Purkinje cell nuclear condensation, and DNA damage in rat cerebellum. MT (i.p) cotreatment with ACR not only recovered weight and gait of rats, but also decreased nuclear condensation and DNA damage in rat cerebellum. Using MDA generation, glutathione (GSH) level, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities in rat cerebellum as indicators, MT alleviated ACR-induced lipid peroxidation and depressed antioxidant capacity. Our results suggest that MT effectively prevents oxidative damage induced by ACR.

CALGB 170601: A phase III double blind trial of duloxetine to treat painful chemotherapy-induced peripheral neuropathy (CIPN).

CRA9013 Background: CALGB 170601 was a randomized, placebo-controlled phase III trial to determine whether duloxetine reduces painful chemotherapy-induced peripheral neuropathy (CIPN). The secondary study endpoint was treatment-related adverse events. Methods: The study used a double-blinded placebo-controlled crossover design with equally weighted randomization to one of two arms. Arm A participants received duloxetine followed by placebo. Arm B participants received placebo followed by duloxetine. The initial and crossover periods each consisted of six weeks of drug/placebo followed by one week of washout. Randomization was stratified by neurotoxic agent and high risk for developing painful CIPN. Eligible patients were 18 years or older with an average CIPN pain score > 4/10 attributed to prior single agent taxane or platinum treatment. Participants took one capsule daily (30mg) for one week, and then two capsules (60mg) daily for four additional weeks. Participants completed the Brief Pain Inventory-Short Form (BPI-SF) at baseline and then weekly. The primary study endpoint was the change in BPI-SF scores within the initial treatment period. Analysis of covariance with an intent-to-treat approach was used to test the effect of treatment on change in pain score. Results: The target accrual goal (N = 231) was met, of which 185 (80%) completed the initial treatment period. Oxaliplatin was the most commonly received neurotoxic agent (59%). Individuals receiving duloxetine over the initial treatment period had a larger average decrease in pain score (mean change score = -1.09; S.E. = 0.19) than those receiving placebo (mean change score = -0.33; S.E. = 0.18) (p = 0.004). There was no difference in duloxetine efficacy based on the specific neurotoxic agent received. Severe (Grade 3) non-hematologic toxicity was reported by 11%, and 41% reported moderate (Grade 2) toxicities. The incidence of Grade 2+ fatigue, the most commonly reported side effect, was significantly higher in the duloxetine arm as compared to placebo (11% vs. 3%, p = 0.029). Conclusions: Duloxetine 60mg daily is an efficacious and well-tolerated intervention for the treatment of taxane or platinum-related painful CIPN.