Edaravone attenuates H2O2 or glutamate-induced toxicity in hippocampal neurons and improves AlCl3/D-galactose induced cognitive impairment in mice.

Edaravone (Eda) is a free radical scavenger used in clinical trials for the treatment of ischemic stroke and amyotrophic lateral sclerosis. However, how Eda exerts its neuroprotective effects remains to be elucidated. We investigated the neuroprotective effects of Eda in cultured hippocampal neurons and in a mouse model of AlCl3/D-galactose-induced cognitive impairment. Eda protected hippocampal neurons by eliminating H2O2 or glutamate-induced toxicity, leading to decreased cell viability and neurite shortening. Consistently, Eda restored impaired levels of BDNF, FGF2 and their associated signaling axes (including TrkB, p-Akt and Bcl-2) to attenuate neuronal death. In a mouse model of chemically-induced cognitive impairment, Eda restored the levels of BDNF, FGF2 and TrkB/Akt signaling axis to attenuate neuronal apoptosis, thereby ameliorating cognitive impairment. Meanwhile, the pro-inflammation was eliminated due to the restoration of pro-inflammatory factors such as TNF-α, IL-6, IL-1ß, and NOS2. In summary, Eda is an effective drug for protecting neurons from neurotoxic injury. BDNF, FGF2, and their regulated pathways may be potential therapeutic targets for neuroprotection.

Edaravone protects rat astrocytes from oxidative or neurotoxic inflammatory insults by restoring Akt/Bcl-2/Caspase-3 signaling axis.

Astrocytes are the major glia cells in the central nervous system (CNS). Increasing evidence indicates that more than to be safe-guard and supporting cells for neurons, astrocytes play a broad spectrum of neuroprotective and pathological functions. Thus, they are compelling models to decipher mechanistic insights of glia cells to CNS insults and for the development of drugs. Edaravone is a free radical scavenger with the capacity to eliminate hydroxyl radicals and lipid peroxides. In this study, we examined the neuroprotective effects of edaravone in rat astrocytes challenged by hydrogen peroxide (H2O2) or bacterial lipopolysaccharides (LPS), respectively. We discovered that edaravone attenuated H2O2-induced oxidative stress by reactivating the Akt signaling axis and antagonistically restoring the expression of apoptosis associated regulators such as Bcl-2 and Caspase-3. Consistently, inhibition of Akt signaling by LY294002 attenuated the anti-oxidative activity of edaravone. In addition, edaravone mitigated LPS-induced morphological changes in astrocytes and alleviated the inflammatory activation and expression of TNF-α, IL-1ß, IL-6 and NOS2. In summary, our data suggested that edavarone effectively protects astrocytes from oxidative stress or infectious insults, which may pave a new avenue for its application in preclinical research and human disease therapeutics.

Ginsenoside Rg1 ameliorates the cognitive deficits in D-galactose and AlCl3-induced aging mice by restoring FGF2-Akt and BDNF-TrkB signaling axis to inhibit apoptosis.

Ginsenoside Rg1 is the main active ingredient of Panax ginseng with the activity of neuroprotective, antioxidant and strengthening the immune system. Therefore, we hypothesized that Rg1 may afford anti-aging effects although the mechanism remains to be elucidated. In this study, chemically induced aging mice were established by consecutive administration of D-galactose and AlCl3. We found that Rg1 effectively ameliorates spatial learning and memory deficits in aging mice demonstrated by their improved performance in step down avoidance tests and Morris water maze experiments. Rg1 restored aging-induced decline of FGF2 and BDNF, reactivated TrkB/Akt signaling pathways in the hippocampus and prefrontal cortex to inhibit apoptosis, for the expression of anti-apoptotic protein Bcl-2 and apoptosis promoting enzyme cleaved-Caspase3 were antagonistically restored. Therefore, these results established the anti-aging effects of Rg1, and FGF2, BDNF and associated signaling pathways might be promising targets. Our data may provide a new avenue to the pharmacological research and diet therapeutic role of ethnic products such as Rg1 in anti-aging and aging associated diseases.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside attenuates MPP+/MPTP-induced neurotoxicity in vitro and in vivo by restoring the BDNF-TrkB and FGF2-Akt signaling axis and inhibition of apoptosis.

The major bioactive ingredient THSG of Polygonum multiflorum is well established for its anti-oxidation, anti-aging and anti-inflammation properties. Increasing evidence supports the capacity of THSG to ameliorate the biochemistry of neurotrophins and their downstream signaling axis in mouse models to attenuate neurodegenerative diseases such as Alzheimer's and Parkinson's disease. In this study, the neuroprotective effects of THSG were studied in vitro and in vivo. In cultured mesencephalic dopamine neurons and SH-SY5Y cell line, it was found that THSG protected the integrity of the cell body and neurite branching from MPP+-induced toxicity by restoring the expression of FGF2 and BDNF and their downstream signaling pathways to inhibit apoptosis and promote cell survival. The inhibition of Akt signaling by LY294002 or TrkB activity by K252a eliminated the neuroprotective effects of THSG. In the MPTP-induced mouse models of Parkinson's disease, THSG ameliorated the animal behaviors against MPTP-induced neurotoxicity, which was demonstrated by the pole test and the tail suspension test. Biochemical and immunohistochemical analysis verified the THSG-mediated restoration of the FGF2-Akt and BDNF-TrkB signaling axis in the substantia nigra and corpus striatum and the recovery of dopaminergic neurons. These results establish the neuroprotective effects of THSG in vitro and in vivo and unravel the underlying mechanism against toxin-induced neural atrophy, providing a new avenue for the use and pharmacological research of edible medicine for anti-neurodegenerative diseases.

[Effects of root-excision on trunk hydraulic traits and growth status of Ginkgo biloba].

The roots of 8-year-old Ginkgo biloba saplings were partially excised to three degrees to study the effects of root-excision on the trunk hydraulic traits and growth status of the saplings. The three degrees were severe, medium, and light (8:1, 10:1, and 12:1 of excised root diameter to base diameter of tree trunk, respectively). Physiological parameters including trunk ultrasound acoustic emission (UAE) signal, branch percentage loss of hydraulic conductance (PLC), sap flow flux, and leaf stomatal conductance, transpiration rate and water potential were measured periodically after root-excision. In all treatments, a great number of trunk UAE signal produced after a short time of root-excision, peaked at 6 h, and decreased gradually then. The intensity of the UAE signals increased with increasing root-excision degree. After root-excision, the branch PLC increased rapidly in the first 12 h but slowly after 24 h. The sap flow flux, leaf stomatal conductance, transpiration rate and water potential after root-excision decreased obviously, with significant differences among the three treatments. The cumulative number of UAE signals (cUAE) was significantly and positively correlated with branch embolism degree, while negatively correlated with sap flow flux and leaf water potential. The leaf area and new branch length of G. biloba in the next year after root-excision decreased significantly, and the decrement was increased with root-excision degree. Root-excision not only made the degrees of conduits cavitation and branch embolism increased, but also affected water transportation and leaf transpiration rate within a short period of time, which would in turn give an impact on G. biloba plant growth.