AGX-0104

Chronic epilepsy is mainly characterized by spontaneous recurrent seizures (SRS). The peroxisome proliferator activated receptor gamma/phosphatase and tensin homolog/protein kinase B (PPARγ/PTEN/Akt) pathway is involved in the pathogenesis of SRS and neuronal loss. Curcumin is a natural compound, and previous studies have shown it provides neuroprotection via anti‐inflammation and anti‐oxidant effects in many central nervous system (CNS) diseases. In the present study, we show that curcumin regulates the abnormal expression of PTEN and Akt in the SRS phase, improves the neuronal loss in the hippocampus, and suppresses SRS development and seizure spike activity in epileptic rats. More importantly, these effects are reversed by the PPARγ antagonist, T0070907, suggesting that curcumin exerts neuroprotective and anti‐epileptic effects through the PPARγ/PTEN/Akt signaling pathway. Other studies have shown that curcumin can cross the BBB and has a safety profiles and pleiotropic pharmacological effects. Thus, our data support the proposition that curcumin might be a potential neuroprotective and anti‐epileptic agent for chronic epilepsy.

Ischemic stroke (IS) remains a challenge in clinical treatment due to limited therapeutic options. While artemisinin (ART), an antimalarial drug, shields against acute IS via anti-inflammatory, antioxidant, and anti-apoptotic properties, the long-term benefits and specific underlying mechanisms have not been fully elucidated. Here, we investigate whether ART ameliorates IS injury and promotes neurogenesis by activating the peroxisome proliferator-activated receptor γ (PPARγ)-dependent M2 microglial polarization.

The experimental models included transient middle cerebral artery occlusion/reperfusion (MCAO/R) in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) in primary microglial cultures to simulate IS. The therapeutic effects of ART were evaluated by neurological functions and infarct volume. PPARγ inhibitor T0070907 (T007) was intraperitoneally injected 24 h following MCAO/R at a dose of 2 mg/kg in vivo and a concentration of 10 μM for 30 min before OGD in vitro. We utilized real-time quantitative polymerase chain reaction (RT-qPCR) along with Western blot analyses to detect the microglia markers and PPARγ. The proliferation and differentiation of neural stem cells (NSCs) both in vivo and in vitro were assessed via immunofluorescence labeling. The neurogenic potential of ART-treated microglia was investigated by conditioned medium. The levels of brain-derived growth factor (BDNF) and insulin-like growth factor-1 (IGF-1) in microglia were measured by immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA).

ART treatment significantly alleviated short- and long-term neurological deficits and reduced cerebral infarct volume in rats with IS. Experiments conducted both in vivo and in vitro experiments illustrated that ART directed microglia away from the pro-inflammatory M1 state towards the anti-inflammatory M2 state, enhanced neurogenesis, and upregulated the expression of PPARγ, BDNF, and IGF-1. In addition, the conditioned medium from ART-exposed microglia stimulated the proliferation and neuronal differentiation of primary NSCs. However, these positive effects were effectively counteracted by the use of PPARγ inhibitor T0070907 (T007).

Our findings demonstrate that ART ameliorates IS injury and promotes neurogenesis mainly through PPARγ-mediated microglia M2 polarization. Therefore, ART can be considered a potential therapeutic drug for IS.