Osthole Activates the Cholinergic Anti-Inflammatory Pathway via α7nAChR Upregulation to Alleviate Inflammatory Responses.

Osthole (also known as Osthol) is the main anti-inflammatory coumarin found in Cnidium monnieri and severs as the exclusive quality-controlled component according the Chinese Pharmacopoeia. However, its underlying anti-inflammatory mechanism remains unknown. In this study, we demonstrated that Osthole treatment significantly inhibited the generation of TNF-α, but not IL-6 in the classical LPS-stimulated RAW264.7 macrophage model. In addition, LPS induced the activation of both MAPK and NF-κB signalling pathways, of which the former was dose-dependently restrained by Osthole via suppressing the phosphorylation of JNK and P38 proteins, while the phosphorylation of IκB and P65 proteins remained unaffected. Interestingly, Osthole dose-dependently up-regulated the expression of the key cholinergic anti-inflammatory pathway regulator α7nAChR, and the TNF-α inhibition effect of Osthole was also significantly alleviated by the treatment of α7nAChR antagonist methylbetaine. These results demonstrate that Osthole may regulate TNF-α by promoting the expression of α7nAChR, thereby activate the vagus nerve-dependent cholinergic anti-inflammatory pathway.

Diterpenoids from Euphorbia fischeriana with Kv1.3 Inhibitory Activity.

Euphorbia diterpenoids possess inhibitory effects of Kv1.3 ion channel, but most of this research has focused on diterpenoids with jatrophane-related or ingenane-related skeletons. In the present study, nine undescribed (1-9) and 16 known (10-25) diterpenoids, based on jatrophane, lathyrane, ingenane, abietane, and atisane skeletons, were identified from the methanol extract of the aerial parts of Euphorbia fischeriana. The structures were established by analysis of the spectroscopic data as well as by single-crystal X-ray diffraction analysis. Among the isolated diterpenoids, macrocyclic jatrophanes and lathyranes exerted Kv1.3 blocking activity. Compound 8 exhibited good selectivity on the inhibition of the Kv 1.3 channel rather than hERG channel, with a selectivity index over 7.0. The selective activity of lathyrane diterpenoids indicates that macrocyclic diterpenoids have the potential to be further investigated as therapeutic agents for the treatment of autoimmune diseases.

Rare Carbon-Bridged Citrinin Dimers from the Starfish-Derived Symbiotic Fungus Penicillium sp. GGF16-1-2.

Four novel, rare carbon-bridged citrinin dimers, namely dicitrinones G-J (1-4), and five known analogs (5-9) were isolated from the starfish-derived fungus Penicillium sp. GGF 16-1-2. Their structures were elucidated by extensive spectroscopic analysis and quantum chemical calculations. Compounds 1-9 exhibited strong antifungal activities against Colletotrichum gloeosporioides with LD50 values from 0.61 µg/mL to 16.14 µg/mL. Meanwhile, all compounds were evaluated for their cytotoxic activities against human pancreatic cancer BXPC-3 and PANC-1 cell lines; as a result, compound 1 showed more significant cytotoxicities than the positive control against both cell lines. In addition, based on the analyses of the protein-protein interaction (PPI) network and Western blot, 1 could induce apoptosis by activating caspase 3 proteins (CASP3).

Glycyrrhetinic acid alleviates acute lung injury by PI3K/AKT suppressing macrophagic Nlrp3 inflammasome activation.

Glycyrrhetinic acid (GA), a triterpene saponins, has been widely proven to have multiple medicinal properties. Our study aimed to figure out the protective effect of GA on acute lung injury (ALI) and the underlying mechanism. The LPS-induced ALI model mice were intratracheally administrated with 10 mg/kg LPS. Pretreatment with GA (10, 20, 40 mg/kg, i.g.) ameliorated acute lung injury pathological damage, macrophage infiltration and lung edema. In the lung tissue, immunofluorescence (IF) and Immunohistochemistry (IHC) were performed to detect macrophage Nod-like receptor 3 (Nlrp3) inflammasome activation and interleukin-1ß (IL-1ß) protein expression. In macrophages, the co-localization of Nlrp3 with caspase-1 and Nlrp3 with ASC were assessed by IF. The translational and transcriptional level of Nlrp3, cle-caspase-1 and apoptosis-associated speck-like protein containing CARD (ASC), were examined by Western blot and Real time PCR (RT-PCR). The protein expression of Cle-caspase-1 was remarkably suppressed via sh-Nlrp3 transfection compared with LPS groups. GA notably attenuated ALI by inhibiting Nlrp3 formation and activation. Furthermore, GA downregulated the production of reactive oxygen species (ROS) and the phosphorylation level of PI3K and AKT in macrophages. These findings indicate that GA ameliorated ALI in mice by suppressing the activation of Nlrp3 inflammasome which may be mediated by ROS-PI3K/AKT pathway. GA may serve as a promising agent for the attenuation of ALI-related inflammation and pathology.

The marine Penicillium sp. GGF16-1-2 metabolite dicitrinone G inhibits pancreatic angiogenesis by regulating the activation of NLRP3 inflammasome.

Citrinin derivatives have been found to have various pharmacological activities, such as anti-inflammatory, anti-tumor, and antioxidant effects. Dicitrinone G (DG) was a new citrinin dimer isolated from marine-derived fungus Penicillium sp. GGF 16-1-2 which has potential activity. Here, we aim to investigate whether DG has anti-pancreatic cancer activity. In xenograft tumor model, 2 × 106 BXPC-3 cells were injected into the hind flank of NU/NU nude mice by subcutaneously for 2 weeks followed by treating with DG (0.25, 0.5, 1 mg/kg) and 5-FU (30 mg/kg) for 4 weeks. Tumor volume and weight were measured, and the expression of CD31, IL-18, NLRP3, and Caspase-1 in tumor tissue were detected. In vitro, HUVECs were treated with conditioned medium (CM) derived from BXPC-3 cells, the effects of DG on angiogenesis were detected by tube formation and western blot analysis. In vivo studies showed that the tumor growth and angiogenesis were greatly suppressed. The tumor weight inhibition rates of DG and 5-FU groups were about 42.36%, 38.94%, 43.80%, and 31.88%. Furthermore, the expression of CD31 and Caspase-1 were decreased. In vitro, CM derived from BXPC-3 cells which treated with DG could inhibit the tube formation and expression of pro-angiogenic NICD in HUVECs. Our study suggests that DG could suppress angiogenesis via the NLRP3/IL-18 pathway and may have the potential to inhibit tumor development.

NLRP3 inflammasome-mediated Pyroptosis induce Notch signal activation in endometriosis angiogenesis.

Endometriosis is characterized by the presence of endometrial tissue outside the uterus that not only causes severe pelvic pain and infertility but also increased risk for ovarian carcinogenesis in women of reproductive age. Here, we found that angiogenesis was increased and accompanied with up-regulation of Notch1 in human endometriotic tissue sample, which is associated with pyroptosis induced by activation of endothelial NLRP3 inflammasome. Further, in endometriosis model induced in wild type and NLRP3-deficient (NLRP3-KO) mice, we found that deficiency of NLRP3 suppressing the development of endometriosis. In vitro, inhibiting the activation of NLRP3 inflammasome prevents LPS/ATP-induced tube formation in endothelial cells. Meanwhile, knockdown NLRP3 expression by gRNA disrupt the interaction between Notch1 and HIF-1α under the inflammatory microenvironment. This study demonstrates that activation of NLRP3 inflammasome-mediated pyroptosis affects angiogenesis in endometriosis via Notch1-dependent manner.