[Effects of Yizhi Tiaoshen acupuncture on learning and memory function and the expression of phosphorylated tau protein in the hippocampus of Alzheimer's disease model rats].

OBJECTIVE: To observe the effects of Yizhi Tiaoshen (benefiting mental health and regulating the spirit) acupuncture on learning and memory function, and the expression of phosphorylated tubulin-associated unit (tau) protein in the hippocampus of Alzheimer's disease (AD) model rats, and explore the effect mechanism of this therapy on AD. METHODS: A blank group and a sham-operation group were randomly selected from 60 male SD rats, 10 rats in each one. AD models were established in the rest 40 rats by the intraperitoneal injection of D-galactose and okadaic acid in the CA1 region of the bilateral hippocampus. Thirty successfully-replicated model rats were randomly divided into a model group, a western medication group and an acupuncture group, 10 rats in each one. In the acupuncture group, acupuncture was applied to "Baihui" (GV 20), "Sishencong" (EX-HN 1), "Neiguan" (PC 6), "Shenmen" (HT 7), "Xuanzhong" (GB 39) and "Sanyinjiao" (SP 6); and the needles were retained for 10 min. Acupuncture was given once daily. One course of treatment was composed of 6 days, with the interval of 1 day; the completion of treatment included 4 courses. In the western medication group, donepezil hydrochloride solution (0.45 mg/kg) was administrated intragastrically, once daily; it took 7 days to accomplish one course of treatment and a completion of intervention was composed of 4 courses. Morris water maze (MWM) and novel object recognition test (NORT) were used to assess the learning and memory function of the rats. Using HE staining and Nissl staining, the morphological structure of the hippocampus was observed. With Western blot adopted, the protein expression of the tau, phosphorylated tau protein at Ser198 (p-tau Ser198), protein phosphatase 2A (PP2A) and glycogen synthase kinase-3ß (GSK-3ß) in the hippocampus was detected. RESULTS: There were no statistical differences in all of the indexes between the sham-operation group and the blank group. Compared with the sham-operation group, in the model group, the MWM escape latency was prolonged (P<0.05), the crossing frequency and the quadrant stay time in original platform were shortened (P<0.05), and the NORT discrimination index (DI) was reduced (P<0.05); the hippocampal cell numbers were declined and the cells arranged irregularly, the hippocampal neuronal structure was abnormal and the numbers of Nissl bodies decreased; the protein expression of p-tau Ser198 and GSK-3ßwas increased (P<0.05) and that of PP2A decreased (P<0.05). When compared with the model group, in the western medication group and the acupuncture group, the MWM escape latency was shortened (P<0.05), the crossing frequency and the quadrant stay time in original platform were increased (P<0.05), and DI got higher (P<0.05); the hippocampal cell numbers were elevated and the cells arranged regularly, the damage of hippocampal neuronal structure was attenuated and the numbers of Nissl bodies were increased; the protein expression of p-tau Ser198 and GSK-3ß was reduced (P<0.05) and that of PP2A was increased (P<0.05). There were no statistically significant differences in the above indexes between the acupuncture group and the western medication group (P>0.05). CONCLUSION: Acupuncture therapy of "benefiting mental health and regulating the spirit" could improve the learning and memory function and alleviate neuronal injure of AD model rats. The effect mechanism of this therapy may be related to the down-regulation of GSK-3ß and the up-regulation of PP2A in the hippocampus, and then to inducing the inhibition of tau protein phosphorylation.

Plastome evolution in the East Asian lobelias (Lobelioideae) using phylogenomic and comparative analyses.

Lobelia species, as rich source of the alkaloid lobeline which has been shown to have important biological activity, have been used in folk medicine throughout East Asia to treat various diseases. However, Lobelia is a complex and varied genus in East Asia and is thus difficult to identify. Genomic resources would aid identification, however the availability of such information is poor, preventing a clear understanding of their evolutionary history from being established. To close this gap in the available genomic data, in this study, 17 plastomes of East Asian lobelias were newly sequenced and assembled. Although the plastomes of Lobelia sect. Hypsela, L. sect. Speirema, and L. sect. Rhynchopetalum shared the gene structure, the inverted repeat (IR)/large single copy (LSC) boundaries, genome size, and the number of repeats were variable, indicating the non-conservative nature of plastome evolution within these sections. However, the genomes of the Lobelia sect. Delostemon and L. sect. Stenotium showed rearrangements, revealing that these two sections might have undergone different evolutionary histories. We assessed nine hotspot genes and 27-51 simple sequence repeat motifs, which will also serve as valuable DNA barcode regions in future population genetics studies and for the delineation of plant species. Our phylogenetic analysis resolved the evolutionary positions of the five sections in agreement with previous evolutionary trees based on morphological features. Although phylogenetic reconstruction of Lobelioideae based on the rpoC2 gene has rarely been performed, our results indicated that it contains a considerable amount of phylogenetic information and offers great promise for further phylogenetic analysis of Lobelioideae. Our site-specific model identified 173 sites under highly positive selections. The branch-site model exhibited 11 positive selection sites involving four genes in the East Asian branches. These four genes may play critical roles in the adaptation of East Asian taxa to diverse environments. Our study is the first to detect plastome organization, phylogenetic utility, and signatures of positive selection in the plastomes of East Asian lobelias, which will help to further advance taxonomic and evolutionary studies and the utilization of medicinal plant resources.

Cytotoxic diaporindene and tenellone derivatives from the fungus Phomopsis lithocarpus.

Nine new compounds, including five natural rarely-occurring 2, 3-dihydro-1H-indene derivatives named diaporindenes E-I (1-5), and four new benzophenone analogues named tenellones J-M (6-9) were isolated from the deep-sea sediment-derived fungus Phomopsis lithocarpus FS508. All the structures for these new compounds were fully characterized on the basis of spectroscopic data, NMR spectra, and ECD calculation and single-crystal X-ray diffraction analysis. The potential anti-tumor activities of compounds 1-9 against four tumor cell lines SF-268, MCF-7, HepG-2, and A549 were evaluated using the SRB method. Compound 7 exhibited cytotoxic activity against the SF-268 cell line with an IC50 value of 11.36 µmol·L-1.

Prenylated stilbenes and flavonoids from the leaves of Cajanus cajan.

Three new prenylated stilbenes, named as cajanusins A-C (1-3), and one new natural product cajanusin D (4), along with six known derivatives (5-10) were isolated from the leaves of Cajanus cajan. Their structures were fully elucidated by means of extensive spectroscopic methods and comparison with data in the reported literatures. The new compounds of 1 and 2 were evaluated for in vitro cytotoxic activities against a panel of human cancer cell lines.

Two pairs of enantiomeric propylated flavonoids and a new lignan from the aerial parts of Abrus precatorius.

Two pairs of novel enantiomeric flavonoids (1a, 1b and 2a, 2b), along with one new lignan (3), were isolated from the aerial parts of Abrus precatorius. All of these enantiomeric flavonoids featured an unprecedented propylated flavonoid skeleton representing a new family of flavonoid, and the new lignan was found to have an attractive arachidate ester side chain. Their structures were extensively elucidated by means of detailed NMR and mass spectroscopic analysis. Moreover, biological evaluation of antibacterial activity for these compounds against Bacillus cereus and Escherichia coli were conducted.

Two new metabolites from Daldinia eschscholtzii, an endophytic fungus derived from Pogostemon cablin.

The chemical investigation of the mycelia of endophytic fungus Daldinia eschscholtzii A630, which was isolated from the medicinal plant Pogostemon cablin, resulted in the isolation of two new compounds, named eschscholin A (1), 3-ene-2-methyl-2H-1-benzopyran-5-ol (2), and one new natural product 3,5-dihydroxy-2-methyl-4H-chromen-4-one (3), along with seven known compounds. Their structures were fully characterized by means of detailed spectroscopic analysis, and in comparison with published data for known compounds. All of the isolated compounds (1-10) were evaluated for their antibacterial activities.

Rhodomyrtosone B, a membrane-targeting anti-MRSA natural acylgphloroglucinol from Rhodomyrtus tomentosa.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Rhodomyrtus tomentosa are traditionally used in the treatment of infectious diseases such as wound infections in Chinese traditional medicine. The mechanisms of the activity of rhodomyrtosone B (RDSB), a natural acylphloroglucinol isolated from the leaves of Rhodomyrtus tomentosa, are still not understood. We provided a detailed investigation of the antibacterial action of RDSB against bacteria in vitro and in vivo. MATERIALS AND METHODS: The antibacterial activity of RDSB was tested by the microdilution method against a panel of bacteria, and a time-killing assay was carried out according to CLSI guidelines. The cytotoxic potential of RDSB was evaluated against mammalian cells, and its haemolytic activity towards rabbit red blood cells (RBCs) was assessed. The mode of action of RDSB was investigated by targeting bacterial membranes, and its resistance was evaluated using a sequential passaging method. The antibacterial activities in vivo were assessed against MRSA in a mouse skin infection mode. RESULTS: RDSB exhibited distinct antibacterial activities against selected Gram-positive pathogens responsible for serious infections, even including methicillin-resistant Staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 0.62-1.25 µg/mL and vancomycin-resistant Enterococcus faecium (VRE) with an MIC of 2.5 µg/mL. RDSB displayed much more rapid bactericidal activity against MRSA than that of vancomycin. The membrane-targeting experiments revealed that RDSB exhibited significant antibacterial activity with the perturbation of bacterial membrane potential and an increase in membrane permeability. In particular, RDSB had weak cytotoxicity to mammalian cells (IC50 >14 µg/mL) and has advantageous specificity against selected Gram-positive bacterial membranes rather than RBCs. Notably, RDSB displayed in vitro antibacterial activities against MRSA without drug-resistance and profoundly attenuated the skin ulcer formation in a murine model of MRSA infection under a single dose of 40 µg RDSB per mouse. CONCLUSION: RDSB has profound antibacterial activity against drug-resistant bacteria (MRSA and VRE) and low cytotoxicity. It is bactericidal in nature, and an increase in membrane permeability resulting from membrane perturbation is one of its modes of action. RDSB represents a promising natural antibiotic to combat drug-resistant (MRSA and VRE) infections.

Brachyanins A-C, pinene-derived meroterpenoids and phloroglucinol derivative from Leptospermum brachyandrum.

A pair of epimer brachyanins A (1) and B (2), along with a new phloroglucinol brachyanin C (3), were isolated from the leaves of Leptospermum brachyandrum. Brachyanins A (1) and B (2) were the first example of novel meroterpenoid with a unique skeleton that combined a synacrpic acid and a pinene units via a benzyl moiety. Their structures were elucidated through the application of extensive spectroscopic measurements and single-crystal X-ray diffraction analysis and with the absolute configurations of 1 and 2 were confirmed by the quantum chemical CD calculation. The hetero Diels-Alder as the key biotransformation was proposed to account for the biosynthesis of brachyanins A and B sheding light by the potential procursor brachyanin C.

[Sesquiterpenoids of endophytic fungus Cerrena sp. from Pogostemon cablin and their cytotoxic activities].

The secondary metabolites of endophytic fungus Cerrena sp.A593 from Pogostemon cablin and their cytotoxic activities were investigated. Eight sesquiterpenoids were isolated from the fermentation broth of the strain A593 by silica gel, reverse phase silica gel, Sephadex LH-20, HPLC and so on. Their structures were identified as chloriolin B(1), chloriolin C(2), pleurocybellone A(3), dihydrohypnophilin(4), cucumin F(5), antrodin A(6), 10α-hydroxyamorphan-4-en-3-one(7), and connatusin A(8). Compounds 1- 8 were firstly found from the genus Cerrena. All isolated sesquiterpenoids were evaluated for in vitro cytotoxic activities against HepG-2, SF-268, MCF-7 and NCI-H460 tumor cell lines. Compounds 1-3 showed inhibitory activities against the four tumor cell lines with IC50 values ranging from 20.33 to 63.13 µmol•L⁻¹.

Callistemenonone A, a novel dearomatic dibenzofuran-type acylphloroglucinol with antimicrobial activity from Callistemon viminalis.

A new acylphloroglucinol with a novel architecture including an unprecedented dearomatic dibenzofuran core, named callistemenonone A (1), was isolated from the leaves of Callistemon viminalis (Myrtaceae). The structure was fully characterized on the basis of extensive spectroscopic analysis, including UV, HRESIMS, as well as 1D and 2D NMR spectral data (HSQC, HMBC, and ROESY). The deduced structure represents the first example of a natural dibenzofuran with two phenyl moieties coupling through tertiary hydroxy and ketal carbons. A plausible biogenetic pathway involving oxidative coupling and dearomatization as key steps is proposed to account for the biosynthesis of this novel class of dibenzofuran. Moreover, antimicrobial assays, in conjunction with the time-killing and biophysical studies, revealed that 1 exerted potent bactericidal activity against a panel of methicillin resistant pathogenic microbes with a unique mechanism.

Two New Metabolites from the Endophytic Fungus Alternaria sp. A744 Derived from Morinda officinalis.

Two new compounds isobenzofuranone A (1) and indandione B (2), together with eleven known compounds (3-13) were isolated from liquid cultures of an endophytic fungus Alternaria sp., which was obtained from the medicinal plant Morinda officinalis. Among them, the indandione (2) showed a rarely occurring indanone skeleton in natural products. Their structures were elucidated mainly on the basis of extensive spectroscopic data analysis. All of the compounds were evaluated with cytotoxic and α-glucosidase inhibitory activity assays. Compounds 11 and 12 showed significant inhibitory activities against four tumor cell lines; MCF-7, HepG-2, NCI-H460 and SF-268, with IC50 values in the range of 1.91-9.67 µM, and compounds 4, 5, 9, 10, 12 and 13 showed excellent inhibitory activities against α-glucosidase with IC50 values in the range of 12.05-166.13 µM.

Three new highly-oxygenated metabolites from the endophytic fungus Cytospora rhizophorae A761.

Cytosporaphenones A-C, one new polyhydric benzophenone and two new naphtopyrone derivatives, along with eight known ones, were isolated from Cytospora rhizophorae, an endophytic fungus from Morinda officinalis. Their structures were fully characterized by means of detailed spectroscopic analysis and X-ray single crystal diffraction. To our knowledge, the three new compounds were the most highly oxygenated metabolites of their families discovered in nature. Moreover, all of the compounds were evaluated for in vitro cytotoxic activities against MCF-7, NCI-H460, HepG-2 and SF-268 tumor cell lines, and the new compound 1 exhibited weak growth inhibitory activity against the tumor cell lines MCF-7 and HepG-2 with IC50 values of 70 and 60µM, respectively.

Callviminols A-E, new terpenoid-conjugated phloroglucinols from the leaves of Callistemon viminalis.

Callviminols A-E (1-5), five rare phloroglucinols bearing a framework embodying a hexahydrodibenzo[b,d]furan or 2-phenylcyclohexanol nucleus derived from a phloroglucinol-monoterpene adduct, were isolated from the leaves of Callistemon viminalis. Their structures were established via extensive spectroscopic measurements, with the absolute configuration of 5 determined by electronic circular dichroism (ECD) calculations. The plausible biogenetic pathway suggested that a unique oxidative radical addition and classic cationic cyclization were key biosynthetic steps.

Acylphloroglucinols from the leaves of Callistemon viminalis.

A phytochemical study on the leaves of Callistemon viminalis, a widely distributed ornamental and medicinal plant of agricultural importance in China, resulted in the isolation of eleven acylphloroglucinols, including six new ones named callistenones F-K (1-6), as well as five known congeners. Their structures were fully characterized using spectral data interpretation for the new structures and compared to published data for the known ones. All the isolated compounds were evaluated for in vitro antimicrobial activity and growth inhibitory activity against four tumor cell lines (MCF-7, NCI-H460, SF-268 and HepG-2).

Rhodomentones A and B, novel meroterpenoids with unique NMR characteristics from Rhodomyrtus tomentosa.

Two novel meroterpenoids, rhodomentones A and B bearing an unprecedented caryophyllene-conjugated oxa-spiro[5.8] tetradecadiene skeleton, were isolated from the leaves of Rhodomyrtus tomentosa. Their structures with unique NMR characteristics were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction, quantum molecular calculation, chemical transformation as well as total synthesis.

Two new xyloketals from the endophytic fungus Endomelanconiopsis endophytica derived from medicinal plant Ficus hirta.

Chemical examination of the liquid culture of Endomelanconiopsis endophytica A326 isolated from the Chinese folk medicine Ficus hirta resulted in the isolation of two new xyloketals named xyloketals K and L (1-2) and three known analogs (3-5) including a new natural product (5). Their structures were determined on the basis of extensive spectroscopic analysis. All compounds were evaluated for their cytotoxic activities against the SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. Nonetheless, no significant activity was observed.

Cytotoxic cochlioquinone derivatives from the endophytic fungus Bipolaris sorokiniana derived from Pogostemon cablin.

Chemical investigation of the liquid culture of the endophytic fungus Bipolaris sorokiniana A606, which was isolated from the medicinal plant Pogostemon cablin resulted in the isolation of four new cytotoxic compounds, named isocochlioquinones D-E (1-2) and cochlioquinones G-H (3-4), along with five known cochlioquinone analogues (5-9). Their structures were determined on the basis of extensive spectroscopic analysis. Isocochlioquinone D (1) possessed a rare benzothiazin-3-one moiety and cochlioquinone G (3) was the first example of cochlioquinones bearing an indole-4,7-dione fragment. All of the isolates (1-9) were evaluated for their cytotoxic activities against MCF-7, NCI-H460, SF-268 and HepG-2 tumor cell lines by the sulforhodamine B (SRB) assay. Compounds 4 and 6-9, featuring a cochlioquinone core, exhibited potent cytotoxicities in vitro against the four tumor cell lines, and a preliminary structure-activity relationship of these compounds was also discussed.

Cytotoxic trichothecene macrolides from the endophyte fungus Myrothecium roridum.

A new cytotoxic roridin-type trichothecene macrolide named epiroridin acid (1) and two known compounds epiroridin E (2) and mytoxin B (3) were isolated from the liquid culture of Myrothecium roridum A553, which was isolated from the medicinal plant Pogostemon cablin. The structure of the new macrolide (1) was elucidated by extensive spectroscopic measurements (UV, IR, MS, and 1D and 2D NMR) analyses. All isolated compounds (1-3) were evaluated for their cytotoxic activities against SF-268, MCF-7, NCI-H460, and HepG-2 tumor cell lines. The new compound (1) exhibited well cytotoxicity against the four selected tumor cell lines.

[Study on cytotoxic secondary metabolites of endophytic fungus Diaporthe longicolla A616 from Pogostemon cablin].

To study active secondary metabolites of endophytic fungus Diaporthe longicolla A616 isolated from Pogostemon cablin. Ten compounds were isolated from fermentation product of the strain 616 by silica gel, reverse phase silica gel, Sephadex-LH20, HPLC and so on. Their structures were identified as 1,3-diamino-1,3-dimethylurea(1),(7R,9R)-7-hydroxy-9-propyl-5-nonen-9-olide(2), Ergosta-5,7,22-trien-3ß-ol(3),(22E,24R)-ergosta-4,6,8(14)-22-tetraen-3-one(4),(22E,24R)-3ß,5α-dihydroxy-6ß-ergosta-7,22-diene(5), citreoisocoumarin(6), glycerol monolinoleate(7), 1-(2-hydroxyethoxy)ethyl(E)-octadec-9-enoate(8), cyclo-(L-Pro-L-Ala)(9), cyclo(L)-Pro-(L)-Val(10), respectively, based on extensive spectroscopic analysis and literature comparisons. Compounds 6-10 were isolated from the genus Diaporthe for the first time. All isolated compounds were evaluated for in vitro cytotoxic activities against SF-268, MCF-7, NCI-H460 and HepG-2 tumor cell lines. Compounds 4 and 5 showed potent growth inhibitory activities against the four cell lines with IC50 values of 5.3, 6.5, 12.2, 6.1µmol•L⁻¹ and 8.2, 5.2, 6.1, 9.4µmol•L⁻¹, respectively.

Guignardones P-S, New Meroterpenoids from the Endophytic Fungus Guignardia mangiferae A348 Derived from the Medicinal Plant Smilax glabra.

Four new meroterpenoids, guignardones P-S (1-4), and three known analogues (5-7) were isolated from the endophytic fungal strain Guignardia mangiferae A348. Their structures were elucidated on the basis of spectroscopic analysis and single crystal X-ray diffraction. All the isolated compounds were evaluated for their inhibitory effects on SF-268, MCF-7, and NCI-H460 human cancer cell lines. Compounds 2 and 4 exhibited weak inhibitions of cell proliferation against MCF-7 cell line.