Neuronal apoptosis and oxidative stress are involved in most of the neurodegenerative diseases, promoting neuron survival is critical for therapy. Silibinin (SLB), which is derived from the seeds of Silybinisus laborinum L., has been widely used as an antioxidant. Here we tested the neuroprotective effects of SLB and the involved molecular mechanisms. We demonstrated that SLB promoted neuron viability upon hydrogen peroxide (H2O2) challenge and reduced hypoxia/ischemia injury in the middle cerebral artery occlusion (MCAO) mouse model. SLB reversed the decreased level of procaspase-3 and balanced Bcl-2 and Bax expression upon H2O2 insult to inhibit cell apoptosis. Furthermore, SLB suppressed the activation of autophagy by decreasing microtubule-associated protein 1 light chain 3 (LC3-II) and Beclin-1 levels under oxidative stress accordingly. SLB phosphorylated protein kinase B (Akt-1) at Ser473 in a time- and dose-dependent manner. The inhibitor for phosphoinositide-3-kinase (PI3K) wortmannin abrogated SLB-induced phosphorylation of Akt-1 and mTOR, decreased the suppression of autophagy, and therefore abolished SLB-mediated neuroprotection. All the data suggested that SLB protected neurons by inhibiting both the mitochondrial and autophagic cell death pathways. This study opens new avenues for the use of SLB in treatment of central nervous system (CNS) diseases in which oxidative stress plays a major role in disease pathogenesis. Given that it occurs naturally with low toxicity and pleiotropic effects that benefit the nervous system, SLB acts potentially as a novel therapy for ischemic injury.

Transient receptor potential canonical (TRPC) channels are the most prominent nonselective cation channels involved in various diseases. However, the function, clinical significance, and molecular mechanism of TRPCs in colorectal cancer (CRC) progression remain unclear. In this study, we identified that TRPC1 was the major variant gene of the TRPC family in CRC patients. TRPC1 was upregulated in CRC tissues compared with adjacent normal tissues and high expression of TRPC1 was associated with more aggressive tumor progression and poor overall survival. TRPC1 knockdown inhibited cell proliferation, cell-cycle progression, invasion, and migration in vitro, as well as tumor growth in vivo; whereas TRPC1 overexpression promoted colorectal tumor growth and metastasis in vitro and in vivo. In addition, colorectal tumorigenesis was significantly attenuated in Trpc1-/- mice. Mechanistically, TRPC1 could enhance the interaction between calmodulin (CaM) and the PI3K p85 subunit by directly binding to CaM, which further activated the PI3K/AKT and its downstream signaling molecules implicated in cell cycle progression and epithelial-mesenchymal transition. Silencing of CaM attenuated the oncogenic effects of TRPC1. Taken together, these results provide evidence that TRPC1 plays a pivotal oncogenic role in colorectal tumorigenesis and tumor progression by activating CaM-mediated PI3K/AKT signaling axis. Targeting TRPC1 represents a novel and specific approach for CRC treatment.

Ischemic stroke leads to neuronal damage induced by excitotoxicity, inflammation, and oxidative stress. Astrocytes play diverse roles in stroke and ischemia‐induced inflammation, and autophagy is critical for maintaining astrocytic functions. Our previous studies showed that the activation of G protein‐coupled receptor 30 (GPR30), an estrogen membrane receptor, protected neurons from excitotoxicity. However, the role of astrocytic GPR30 in maintaining autophagy and neuroprotection remained unclear. In this study, we found that the neuroprotection induced by G1 (GPR30 agonist) in wild‐type mice after a middle cerebral artery occlusion was completely blocked in GPR30 conventional knockout (KO) mice but partially attenuated in astrocytic or neuronal GPR30 KO mice. In cultured primary astrocytes, glutamate exposure induced astrocyte proliferation and decreased astrocyte autophagy by activating mammalian target of rapamycin (mTOR) and c‐Jun N‐terminal kinase (JNK) and inhibiting p38 mitogen‐activated protein kinase (MAPK) pathway. G1 treatment restored autophagy to its basal level by regulating the p38 pathway but not the mTOR and JNK signaling pathways. Our findings revealed a key role of GPR30 in neuroprotection via the regulation of astrocyte autophagy and support astrocytic GPR30 as a potential drug target against ischemic brain damage.

Herein, we described a highly regio- and enantioselective Friedel–Crafts alkylation of aniline derivatives with in situ generated ortho-quinone methides enabled by chiral phosphoric acid, furnishing a wide range of enantioenriched triarylmethanes bearing three similar benzene rings in high yields (up to 98%) with excellent stereoselectivities (up to 98% ee). Furthermore, the large-scale reactions and diversified transformations of product demonstrate the practicality of the protocol. Density functional theory calculations elucidate the origin of the enantioselectivity.

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