The bioflavonoid apigenin has been shown to possess cancer-preventive and anti-cancer activities. In a drug screening, we found that apigenin can inhibit Wnt/β-catenin signaling, a pathway that participates in pivotal biological functions, which dis-regulation results in various human diseases including cancers. However, the underlying mechanism of apigenin in this pathway and its link to anti-cancer activities remain largely unknown. Here we showed that apigenin reduced the amount of total, cytoplasmic, and nuclear β-catenin, leading to the suppression in the β-catenin/TCF-mediated transcriptional activity, the expression of Wnt target genes, and cell proliferation of Wnt-stimulated P19 cells and Wnt-driven colorectal cancer cells. Western blotting and immunofluorescent staining analyses further revealed that apigenin could induce autophagy-mediated down-regulation of β-catenin in treated cells. Treatment with autophagy inhibitors wortmannin and chloroquine compromised this effect, substantiating the involvement of autophagy-lysosomal system on the degradation of β-catenin during Wnt signaling through inhibition of the AKT/mTOR signaling pathway. Our data not only pointed out a route for the inhibition of canonical Wnt signaling through the induction of autophagy-lysosomal degradation of key player β-catenin, but also suggested that apigenin or other treatments which can initiate this degradation event are potentially used for the therapy of Wnt-related diseases including cancers.

Clinacanthus nutans (Burm. f.) Lindau has been used as a traditional herbal medicine for treating snake bites, scalds, burns, and viral and bacterial infections. It has been attracting an increasing amount of attention because of its biological activities, including its antidiabetic, antioxidant, antibacterial, anticancer, anti-inflammatory, antiviral, and immunoregulatory activities. Here, we conducted a panoramic survey of the literature regarding the immunoregulatory, anti-inflammatory, and antiviral activities of C. nutans. We discovered that C. nutans extracts have virucidal activities against herpes simplex virus types 1 and 2, varicella-zoster virus, cyprinid herpesvirus 3, porcine reproductive and respiratory syndrome virus, mosquito-borne chikungunya virus, and potentially SARS-CoV-2; such activities likely result from C. nutans interfering with the entry, penetration, infection, and replication of viruses. We also reviewed the phytochemicals in C. nutans extracts that exhibit anti-inflammatory and immunoregulatory activities. This updated review of the antiviral, anti-inflammatory, and immunoregulatory activities of C. nutans may guide future agricultural practices and reveal clinical applications of C. nutans.

Defective autophagy is one of the cellular hallmarks of Parkinson’s disease (PD). Therefore, a therapeutic strategy could be a modest enhancement of autophagic activity in dopamine (DA) neurons to deal with the clearance of damaged mitochondria and abnormal protein aggregates. Syringin (SRG) is a phenolic glycoside derived from the root of Acanthopanax senticosus. It has antioxidant, anti-apoptotic, and anti-inflammatory properties. However, whether it has a preventive effect on PD remains unclear. The present study found that SRG reversed the increase in intracellular ROS-caused apoptosis in SH-SY5Y cells induced by neurotoxin 6-OHDA exposure. Likewise, in C. elegans, degeneration of DA neurons, DA-related food-sensitive behaviors, longevity, and accumulation of α-synuclein were also improved. Studies of neuroprotective mechanisms have shown that SRG can reverse the suppressed expression of SIRT1, Beclin-1, and other autophagy markers in 6-OHDA-exposed cells. Thus, these enhanced the formation of autophagic vacuoles and autophagy activity. This protective effect can be blocked by pretreatment with wortmannin (an autophagosome formation blocker) and bafilomycin A1 (an autophagosome–lysosome fusion blocker). In addition, 6-OHDA increases the acetylation of Beclin-1, leading to its inactivation. SRG can induce the expression of SIRT1 and promote the deacetylation of Beclin-1. Finally, we found that SRG reduced the 6-OHDA-induced expression of miR-34a targeting SIRT1. The overexpression of miR-34a mimic abolishes the neuroprotective ability of SRG. In conclusion, SRG induces autophagy via partially regulating the miR-34a/SIRT1/Beclin-1 axis to prevent 6-OHDA-induced apoptosis and α-synuclein accumulation. SRG has the opportunity to be established as a candidate agent for the prevention and cure of PD.

Nine new derivatives of oleanane triterpenoids isolated from Fatsia polycarpa Hayata were synthesized through chemical transformations. Acetylation was effected by reaction with acetic anhydride in pyridine to afford compounds 1–5, while compound 6 was obtained using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) in CH₂Cl₂. The others derivatives 7–9 were obtained in reactions of the corresponding triterpenoids with EDC·HCl, 4-N,N-dimethylaminopyridine hydrochloride and 4-N,N-dimethylaminopyridine in CH₂Cl₂. The structures of 1–9 were elucidated from extensive spectroscopic and HRESIMS data, while the structure of 9 was further confirmed by X-ray diffraction analysis. The cytotoxic, anti-hepatitis B virus (HBV), antibacterial, hypoglycaemic and Wnt signaling activities of these derivatives were evaluated in vitro.

Amyotrophic lateral sclerosis (ALS) is a fatal rare disease of progressive degeneration of motor neurons. The most common genetic mutation in ALS is the hexanucleotide repeat expansion (HRE) located in the first intron of the C9orf72 gene (C9-ALS). HRE can produce dipeptide repeat proteins (DPRs) such as poly glycine-alanine (GA) in a repeat-associated non-ATG (RAN) translation. GA-DPR has been shown to be toxic to motor neurons in various biological models. However, its effects on microglia involved in C9-ALS have not been reported. Here, we show that GA-DPR (GA₅₀) activates the NLR family pyrin domain containing 3 (NLRP3) inflammasome in a human HMC3 microglia model. MCC950 (specific inhibitor of the NLRP3) treatment can abrogate this activity. Next, using yeast two-hybrid screening, we identified sulfide quinone oxidoreductase (SQOR) as a GA₅₀ interacting protein. SQOR knockdown in HMC3 cells can significantly induce the activity of the NLRP3 inflammasome by upregulating the level of intracellular reactive oxygen species and the cytoplasmic escape of mitochondrial DNA. Furthermore, we obtained irisflorentin as an effective blocker of the interaction between SQOR and GA₅₀, thus inhibiting NLRP3 inflammasome activity in GA₅₀-expressing HMC3 cells. These results imply the association of GA-DPR, SQOR, and NLRP3 inflammasomes in microglia and establish a treatment strategy for C9-ALS with irisflorentin.