Arjunolic acid ameliorates lipopolysaccharide-induced depressive behavior by inhibiting neuroinflammation via microglial SIRT1/AMPK/Notch1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Neuroinflammation is involved in the pathogenesis of depression disorder by activating microglia cells, increasing proinflammatory cytokines, effecting serotonin synthesis and metabolism, and neuronal apoptosis and neurogenesis. Arjunolic acid (ARG) is a triterpenoid derived from the fruits of Akebia trifoliata for treating psychiatric disorders in TCM clinic, which exhibits anti-inflammatory and neuroprotective effects. However, its anti-depressive effect and underlying mechanism are unknown. AIM OF THE STUDY: The aim of this study is to explore the effect of arjunolic acid on depression and its possible mechanisms. METHODS: Intraperitoneal injection of LPS in mice and LPS stimulated-BV2 microglia were utilized to set up in vivo and in vitro models. Behavioral tests, H&E staining and ELISA were employed to evaluate the effect of arjunolic acid on depression. RT-qPCR, immunofluorescence, molecular docking and Western blot were performed to elucidate the molecular mechanisms. RESULTS: Arjunolic acid dramatically ameliorated depressive behavior in LPS-induced mice. The levels of BDNF and 5-HT in the hippocampus of the mice were increased, while the number of iNOS + IBA1+ cells in the brain were decreased and Arg1+IBA1+ positive cells were increased after arjunolic acid treatment. In addition, arjunolic acid promoted the polarization of BV2 microglia from M1 to M2 type. Notably, drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA) and molecular docking technologies identified SIRT1 as the target of arjunolic acid. Moreover, after SIRT1 inhibition by using EX-527, the effects of arjunolic acid on ameliorating LPS-induced depressive behavior in mice and promoting M2 Microglia polarization were blocked. In addition, arjunolic acid activated AMPK and decreased Notch1 expression, however, inhibition of AMPK, the effect of arjunolic acid on the downregulation of Notch1 expression were weaken. CONCLUSIONS: This study elucidates that arjunolic acid suppressed neuroinflammation through modulating the SIRT1/AMPK/Notch1 signaling pathway. Our study demonstrates that arjunolic acid might serve as a potiential anti-depressant.

AßPP-tau-HAS1 axis trigger HAS1-related nuclear speckles and gene transcription in Alzheimer's disease.

As the backbone of the extracellular matrix (ECM) and the perineuronal nets (PNNs), hyaluronic acid (HA) provides binding sites for proteoglycans and other ECM components. Although the pivotal of HA has been recognized in Alzheimer's disease (AD), few studies have addressed the relationship between AD pathology and HA synthases (HASs). Here, HASs in different regions of AD brains were screened in transcriptomic database and validated in AßPP/PS1 mice. We found that HAS1 was distributed along the axon and nucleus. Its transcripts were reduced in AD patients and AßPP/PS1 mice. Phosphorylated tau (p-tau) mediates AßPP-induced cytosolic-nuclear translocation of HAS1, and negatively regulated the stability, monoubiquitination, and oligomerization of HAS1, thus reduced the synthesis and release of HA. Furthermore, non-ubiquitinated HAS1 mutant lost its enzyme activity, and translocated from the cytosol into the nucleus, forming nuclear speckles (NS). Unlike the splicing-related NS, less than 1 % of the non-ubiquitinated HAS1 co-localized with SRRM2, proving the regulatory role of HAS1 in gene transcription, indirectly. Thus, differentially expressed genes (DEGs) related to both non-ubiquitinated HAS1 mutant and AD were screened using transcriptomic datasets. Thirty-nine DEGs were identified, with 64.1 % (25/39) showing consistent results in both datasets. Together, we unearthed an important function of the AßPP-p-tau-HAS1 axis in microenvironment remodeling and gene transcription during AD progression, involving the ubiquitin-proteasome, lysosome, and NS systems.

Bisbenzylisoquinoline alkaloids from Plumula Nelumbinis inhibit vascular smooth muscle cells migration and proliferation by regulating the ORAI2/Akt pathway.

Plumula Nelumbinis, the embryo of the seed of Nelumbo nucifera Gaertn, is commonly used to make tea and nutritional supplements in East Asian countries. A bioassay-guided isolation of Plumula Nelumbinis afforded six previously undescribed bisbenzylisoquinoline alkaloids, as well as seven known alkaloids. Their structures were elucidated by extensive analysis of HRESIMS, NMR, and CD data. Pycnarrhine, neferine-2α,2'ß-N,N-dioxides, neferine, linsinine, isolinsinine, and nelumboferine, at 2 µM significantly suppressed the migration of MOVAS cells with inhibition ratio above 50%, more active than that of the positive control cinnamaldehyde (inhibition ratio 26.9 ± 4.92%). Additionally, neferine, linsinine, isolinsinine, and nelumboferine, were also active against the proliferation of MOVAS cells with inhibition ratio greater than 45%. The preliminary structure-activity relationships were discussed. Mechanism studies revealed that nelumboferine inhibited the migration and proliferation of MOVAS cells by regulating ORAI2/Akt signaling pathway.

Semisynthesis of 22,25-Epoxylanostane Triterpenoids: Structure Revision and Protective Effects against Oxygen-Glucose Deprivation/Reoxygenation Injury in H9c2 Cells.

22,25-Epoxylanostane triterpenoids indicated protective effects against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced myocardial injury in a previous study. In order to discover potent cardioprotective agents, 20 22,25-epoxylanostane triterpenoids, including inonotsuoxides A and B, ganodercochlearins A and B, were synthesized from inotodiol (1). The structures of inonotsuoxide B and ganodercochlearin A are revised as 22R,25-epoxylanosta-8-en-3ß,24R-diol (6) and 22S,25-epoxylanosta-7,9(11)-dien-3ß,24R-diol (12) respectively, based on synthesis, spectroscopic data analysis, and X-ray crystallography. Compounds 13-16 and 22 showed potential protective activity against OGD/R-induced injury in H9c2 cells at a concentration of 20 µM. After OGD/R treatment, the most active compounds 13 and 22 at 5 µM increased cell viability by 11.4% and 6.4% respectively, whereas the positive control diazoxide was 14.9% at 100 µM. Flow cytometric analysis and JC-1 staining assay revealed that 13 suppressed OGD/R-induced apoptosis and the mitochondrial membrane potential in H9c2 cells. Compound 13 may serve as a potential lead cardioprotective agent for further development.

Steroidal Saponins from the Rhizomes of Smilax china and Their Inhibitory Effects on Lipopolysaccharide-Induced Proinflammatory Cytokines Expression.

Four new furostanol saponins (1:  - 4: ) and a new pregane-type saponin (5: ) along with six known steroidal saponins (6:  - 11: ) were isolated from the rhizomes of Smilax china. The structures of 1:  - 5: were elucidated by extensive analysis of NMR and HR-ESI-MS data in addition to enzymatic hydrolysis and other chemical methods. Compounds 1, 4: , and 11: showed inhibitory activity against the expression of proinflammatory mediators, inducible nitric oxide synthase, interleukin-1ß, interleukin-6, and tumor necrosis factor-α in lipopolysaccharide-induced RAW264.7 cells. Compound 1: , at a concentration of 20 µM, decreased the production of inducible nitric oxide synthase, interleukin-1ß, interleukin-6, and tumor necrosis factor-α by 36, 62, 72, and 67%, respectively, which is comparable to that of the positive control dexamethasone.

Cardioprotective 22-hydroxylanostane triterpenoids from the fruiting bodies of Phellinus igniarius.

Seven undescribed 22-hydroxylanostane triterpenoids were isolated from the fruiting bodies of Phellinus igniarius, together with three known sterols. Their structures were assigned by extensive spectroscopic and HRESIMS data analyses. The absolute configurations of C-22 were determined by X-ray crystallography, chemical methods, and spectroscopic data comparison. Phellinol G was a 25,26,27-trinorlanostane triterpenoid glycoside. 22S/22R-25,26,27- Trinorlanosta-8-en-3ß,22,24-triols with the same side chain as that of phellinol G were stereoselectively synthesized from commercial lanosterol for the first time. The key step involved Sharpless asymmetrical epoxidation. Phellinols A, B, and F showed cardioprotective activity against oxygen-glucose deprivation/reoxygenation injury in H9c2 cells at a concentration of 20 µM.

Axial Chiral Binaphthoquinone and Perylenequinones from the Stromata of Hypocrella bambusae Are SARS-CoV-2 Entry Inhibitors.

A new axial chiral binaphtoquinone, hypocrellone (1), and a new perylenequinone, hypomycin F (2), were isolated from the stromata of Hypocrella bambusae, together with five known compounds, 3-7. The structures of 1 and 2 were assigned by spectroscopic and HRESIMS data analyses. The axial chirality of 1 was determined by electronic circular dichroism data analysis, and the absolute configurations of 2 and 3 were determined by X-ray crystallography. The axial chirality of 7 was determined by UV-induced photooxidation from 4. Compounds 1, 4, and 5 showed inhibitory activity against pseudotyped SARS-CoV-2 infection in 293T-ACE2 cells with IC50 values of 0.17, 0.038, and 0.12 µM. Compounds 4 and 5 were also active against live SARS-CoV-2 infection with EC50 values of 0.22 and 0.21 µM, respectively. Further cell-cell fusion assays, surface plasmon resonance assays, and molecular docking studies revealed that 4 and 5 could bind with the receptor-binding domain of SARS-CoV-2 S protein to prevent its interaction with human angiotensin-converting enzyme II receptor. Our results revealed that 4 and 5 are potential SARS-CoV-2 entry inhibitors.

A new polyhydroxylated oleanane triterpenoid from the roots of Rhodomyrtus tomentosa.

A new oleanane triterpenoid, 2α,3ß,6ß,23,29-pentahydroxyolean-12-en-28- oic acid (1), was isolated from the roots of Rhodomyrtus tomentosa, together with four known oleanane triterpenoids (2-5) and two known ursane triterpenoids (6-7). The structure of compound 1 was determined by extensive NMR and HR-ESI-MS data analysis. Compounds 4-5 showed cytotoxicity against PC12 cell lines at a concentration of 50 µM, and compound 1 exhibited moderate neuroprotective activity against corticosterone induced PC12 cell death at the same concentration.

Phomopsols A and B from the Mangrove Endophytic Fungus Phomopsis sp. xy21: Structures, Neuroprotective Effects, and Biogenetic Relationships.

A polyketide-derived alkaloid featuring a unique 3,4-dihydro-2H-indeno[1,2-b]pyridine 1-oxide motif, named phomopsol A (1), and a highly oxidized polyketide containing a new 3,5-dihydro-2H-2,5-methanobenzo[e][1,4]dioxepine moiety, named phomopsol B (2), were isolated from the Thai mangrove endophytic fungus Phomopsis sp. xy21, together with the related biosynthetic polyketide 3. The structures of 1-3 were unambiguously established by single-crystal X-ray diffraction analysis (Cu Kα), and their neuroprotective effects in PC12 cells were evaluated. The biosynthetic origins of 1-3 are proposed.

Anti-inflammatory furostanol saponins from the rhizomes of Smilax china L.

Seven new furostanol saponins (1-7), chongrenosides A-G, were isolated from the rhizomes of Smilax china L., together with nine known furostanol saponins (8-16). The structures of the new furostanol saponins (1-7) were elucidated by extensive spectroscopic data analyses (1D and 2D NMR, HRESIMS) and chemical evidence. Compounds 1-6 and 8-16 were evaluated for TNF-α mRNA expression inhibitory activity on LPS induced RAW264.7 cells. Of them, 1, 4, 6, and 11 inhibited the TNF-α mRNA expression by 88%, 87%, 67%, and 93%, respectively, at the concentration of 10 µM.

Ent-abietanes from the Godavari mangrove, Ceriops decandra: Absolute configuration and NF-κB inhibitory activity.

Nine new ent-abietanes, named decandrols A-I (1-9), which could be categorized into three groups (1, 2-6, 7-9), were isolated from the roots of an Indian mangrove, Ceriops decandra, collected in the swamp of Godavari estuary, Andhra Pradesh, together with six previously reported abietanes (10-15), of which the absolute configurations were first determined. The relative and absolute configurations of these compounds were unambiguously established by HR-ESIMS, extensive 1D and 2D NMR investigations, single-crystal X-ray diffraction analysis with Cu Kα radiation, and quantum-chemical electronic circular dichroism (ECD) calculations. Decandrol A (1) is a rare C9-spirofused 7,8-seco-ent-abietane, whereas 2-15 are typically tricyclic ent-abietanes. Decandrols C (3) and E (5) exhibited significant NF-κB inhibitory activity at the concentration of 100 µM.

Achyrodimer F, a tyrosyl-DNA phosphodiesterase I inhibitor from an Australian fungus of the family Cortinariaceae.

Mass-guided isolation of the dichloromethane/methanol extracts from a specimen of teleomorphic fungus of the family Cortinariaceae resulted in the identification of a new dimeric cyclobutane metabolite, achyrodimer F (1), along with the monomers hispidin (2) and bisnoryangonin (3). Their structures were determined by NMR and MS data analyses. Density Function Theory (DFT) NMR calculations was employed to confirm the chemical structure of achyrodimer F. Compound 1 inhibited tyrosyl-DNA phosphodiesterase I with an IC50 value of 1µM.

Steroidal Saponins from the Genus Smilax and Their Biological Activities.

The Smilax species, widely distributed in tropical region of the world and the warm areas of East Asia and North America, are extensively used as folk medicine to treat inflammatory disorders. Chemical investigation on Smilax species showed they are rich sources of steroidal saponins with diversified structure types, including spirostane, isospirostane, furostane, pregnane, and cholestane. This review mainly summarizes the steroidal saponins (1-104) reported from the genus Smilax between 1967 and 2016, and their biological activities. The relationship between structures of steroidal saponins and related biological activities were briefly discussed.

Phenolic Compounds from the Rhizomes of Smilax china L. and Their Anti-Inflammatory Activity.

A new triflavanoid, kandelin B-5 (1), was isolated from the rhizomes of Smilax china L., together with six known phenylpropanoid substituted flavan-3-ols (2-7), nine flavonoids (8-16), two stilbenoids (17, 18), and two other compounds (19, 20). The structure of compound 1 was determined on the basis of 1D, 2D NMR and HR-ESI-MS data, as well as chemical method. Compounds 2-5, 8-12, 15, 17, and 19 were evaluated for anti-inflammatory activity. Only compounds 10, 15 and 17 showed slightly IL-1ß expression inhibitory activities on LPS induced THP-1 cells, with inhibition rate of 15.8%, 37.3%, and 35.8%, respectively, at concentration of 50 µg/mL.

A new dimeric stilbene from the lianas of Gnetum parvifolium.

A new dimeric stilbene, gnetifolin P (1), was isolated from the lianas of Gnetum parvifolium, together with seven known compounds 2-8. The structure of compound 1 was determined by extensive NMR and HRESIMS data analyses, and quantum chemical calculations. All the compounds were evaluated for their anti-inflammatory activity. Compounds 1 and 6 inhibited the expression of IL-1ß on LPS induced THP-1 cells with the inhibition rate of 35.78 and 64.67%, respectively, at concentration of 25 µg/mL.

Tyrosyl-DNA Phosphodiesterase I Inhibitors from the Australian Plant Macropteranthes leichhardtii.

Mass-directed isolation of the CH2Cl2/MeOH extract from the bark of an Australian plant, Macropteranthes leichhardtii, resulted in the purification of a new phenylpropanoid glucoside, macropteranthol (1), together with four known analogues (2-5). The structure of compound 1 was elucidated by NMR and MS data analyses and quantum chemical calculations. Compounds 3 and 5 showed inhibitory activity against tyrosyl-DNA phosphodiesterase I with IC50 values of ∼1.0 µM.

Carboxymethyl- and carboxyl-catechins from ripe Pu-er tea.

Ripe Pu-er tea, a special microbial postfermented tea originated from Yunnan Province, China, since ancient times, is made from green Pu-er tea prepared from the leaves of Camellia sinensis var. assamica (Theaceae). Chemical investigation on thearubigin (n-BuOH-soluble) fraction of the commercial ripe Pu-er tea, led to the identification of four new flavan-3-ol derivatives, 8-carboxymethyl-(+)-catechin (1), 8-carboxymethyl-(+)-catechin methyl ester (2), 6-carboxymethyl-(+)-catechin (3), and 6-carboxyl-(-)-gallocatechin (4), together with 18 known compounds, including other three flavan-3-ol derivatives (5-7), 10 flavonoid glycosides (8-17), two hydrolyzable tannins (18 and 19), two quinic acid derivatives (20-21), and a purine alkaloid (22). Flavonoid glycosides 8-11 are reported from tea plants for the first time. The thearubigin fraction of ripe Pu-er tea was qualitatively analyzed by HPLC, and gallic acid was found to be the major component. Compounds 4, 6-17, 21 and 22 were tested for their acute activities on insulin sensitivity in differentiated 3T3-L1 adipocytes, but none of them showed significant bioactivity at a concentration of 10 µM.

ApoE secretion modulating bromotyrosine derivative from the Australian marine sponge Callyspongia sp.

High throughput screening of a pre-fractionated natural product library identified 11 active fractions showing ApoE modulation activity. Mass-directed fractionation of one active crude extract from the Australian marine sponge Callyspongia sp. resulted in the isolation of 13 metabolites, including three new bromotyrosine derivatives, callyspongic acid (1), 3,5-dibromo-4-methoxyphenylpyruvic acid (2), N-acetyl-3-bromo-4-hydroxylphenylethamine (3), and ten known compounds (4-13). The structure elucidation of compounds 1-3 was based on their 1D and 2D NMR and MS spectroscopic data. 3,5-Dibromo-4-methoxyphenylpyruvic acid (2) showed weak activity in increasing the apolipoprotein E secretion from human CCF-STTG1 cells at the concentration of 40 µM.

Aplysinellamides A-C, bromotyrosine-derived metabolites from an Australian Aplysinella sp. marine sponge.

Mass-directed fractionation of an extract from the Australian marine sponge Aplysinella sp., from the Great Barrier Reef, resulted in the isolation of four new bromotyrosine derivatives, aplysinellamides A-C (1-3) and aplysamine-1-N-oxide (4), along with six known compounds (5-10). The structure elucidation of compounds 1-4 was based on their 1D and 2D NMR and MS spectroscopic data. Aplysamine-1 (6) increased the apolipoprotein E secretion from human CCF-STTG1 astrocytoma cells by 2-fold at the concentration of 30 µM.