New compounds from acid hydrolyzed products of the fruits of Momordica charantia L. and their inhibitory activity against protein tyrosine phosphatas 1B.

Four new cucurbitane-type triterpene sapogenins, compounds 1-4, together with other eight known compounds were isolated from the acid-hydrolyzed fruits extract of Momordica charantia L. Their chemical structures were established by NMR, mass spectrometry and X-ray crystallography. Compounds 1-7 and 9-12 were evaluated for their inhibitory activities toward protein tyrosine phosphatase 1B (PTP1B), a tyrosine phosphatase that has been implicated as a key target for therapy against type II diabetes.

25-Methoxylprotopanaxadiol derivatives and their anti-proliferative activities.

(20R)-25-Methoxyl-dammarane-3β,12β,20-triol (25-OCH₃-PPD) is a dammarane-type sapogenin showing anti-proliferative potential. In our study, two series of analogs substituted at the C-3 or C-3 and C-12 positions with fatty acids were prepared conveniently. The cytotoxic activity of these compounds was evaluated using four different human tumor cell lines (A549, Hela, HT-29 and MCF-7) and a normal cell line (IOSE144).

Biological functions of decorin in cancer.

Decorin is a member of the extracellular matrix small leucine-rich proteoglycans family that exists and functions in stromal and epithelial cells. Accumulating evidence suggests that decorin affects the biology of various types of cancer by directly or indirectly targeting the signaling molecules involved in cell growth, survival, metastasis, and angiogenesis. More recent studies show that decorin plays important roles during tumor development and progression and is a potential cancer therapeutic agent.

Synthesis and anti-tumor evaluation of novel 25-hydroxyprotopanaxadiol analogs incorporating natural amino acids.

In the current study, derivatives of 25-hydroxyprotopanaxadiol (25-OH-PPD) were prepared and their in vitro anti-tumor activities were tested on six different human tumor cell lines by standard MTT assay. The results showed that combining an ester group combined with the presence of an amino acid moiety led to a 10-fold improved anti-tumor activity. Compound 1c exhibited the best anti-tumor activity in the in vitro assays.

Protein tyrosine phosphatase 1B inhibitory effect by dammarane-type triterpenes from hydrolyzate of total Gynostemma pentaphyllum saponins.

Protein tyrosine phosphatase 1B (PTP1B) is an important factor in non-insulin-dependent diabetes mellitus (type-2 diabetes), and a promising target for treatment of diabetes and obesity. Therefore, the aim of this study is to investigate the inhibitory activities of constituents (three new together with twelve known triterpenes compounds) isolated from the hydrolyzate of total saponins from Gynostemma pentaphyllum. Their structures were accomplished mainly base on the spectroscopic methods, and then were further confirmed by X-ray crystal diffraction.

Semi-synthesis and anti-tumor evaluation of novel 25-hydroxyprotopanaxadiol derivatives.

30 novel compounds have been synthesized from 25-hydroxyprotopanaxadiol (25-OH-PPD) and their in vitro anti-tumor activities were tested on three cancer cell lines and one normal cell line (IOSE144) by standard MTT assay. The results showed that compound 27 exhibited the best anti-tumor activity in the in vitro assays. Compounds 1, 2, 16, 17, 18, 27, 28 and 29 have better anti-tumor activities against MCF-7 and A549 cancer cell lines than 25-OH-PPD, together with low toxicity in the normal cell.

New antitumor compounds from Carya cathayensis.

A new lignan (7R,8S,8'R)-4,4',9-trihydroxy-7,9'-epoxy-8,8'-lignan, and three new phenolics, carayensin-A, carayensin-B, and carayensin-C, together with 13 known compounds were isolated from the shells of Carya cathayensis. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. All the compounds were evaluated for cytotoxicity against several human tumor types including human colorectal cancer cell lines (HCT-116, HT-29), human lung cancer cell line (A549), and human breast cancer cell line (MCF-7).

Similar effects of clozapine and olanzapine on ethanol-induced ascorbic acid release in the prefrontal cortex of freely moving mice.

Previous studies have shown that acute systemic administration of ethanol induced ascorbic acid (AA) release in mouse striatum and prefrontal cortex. Clozapine and olanzapine showed similar effects on ethanol-induced AA release in mouse striatum. However, their effects on ethanol-induced AA release in mouse prefrontal cortex have not been reported.

Differential effects of ginsenosides on NO and TNF-alpha production by LPS-activated N9 microglia.

Ginsenosides, the main active components of ginseng, have been reported to exert neuroprotective effects in the central nervous system. In this report, the effects of ginsenoside-Rd and -Rb2, two protopanaxadiols, and ginsenoside-Rg1 and -Re, two protopanaxatriols, on the production of nitric oxide (NO) and TNF-alpha (TNF-alpha) by lipopolysaccharide (LPS)-activated N9 microglial cells were studied. All ginsenosides studied potently suppressed TNF-alpha production in LPS-activated N9 cells.

Effects of clozapine, olanzapine and haloperidol on nitric oxide production by lipopolysaccharide-activated N9 cells.

Schizophrenia is a devastating illness of unknown etiology and the basis for its treatment rests in the symptomatic response to antipsychotics. It was found that some of the patients with schizophrenia elicited microglia activation. The present study used lipopolysaccharide (LPS)-activated mouse microglial cell line N9 as an in vitro model to mimic microglia activation seen in the patients with schizophrenia.

Differential effects of drug-induced ascorbic acid release in the striatum and nucleus accumbens of freely moving rats.

Previous studies have shown that striatum and nucleus accumbens (NAc) are two different structures in mediating addictive drug-induced ascorbic acid (AA) release. In order to further characterize the different effects of drugs-induced AA release in the striatum and NAc, in the present study, we investigated the effect of ethanol, morphine, methamphetamine, nicotine-induced AA release in these two nuclei using microdialysis coupled to high performance liquid chromatography with electrochemical detection (HPLC-ECD). All drugs were continuously perfused directly into the striatum or NAc.

Differential effects of clozapine on ethanol-induced ascorbic acid release in mouse and rat striatum.

Previous studies have shown that acute systemic administration of ethanol-induced striatal ascorbic acid (AA) release in mice and rats. In the present study, in vivo brain microdialysis coupled with high performance liquid chromatography (HPLC) with electrochemical detection (ECD) was used to comparatively evaluate the effects of clozapine on ethanol-induced AA release in mouse and rat striatum. The results showed that clozapine, at the dose of 15 mg/kg i.

Resveratrol inhibits nitric oxide and TNF-alpha production by lipopolysaccharide-activated microglia.

Upon activation, brain macrophages, the microglia, release proinflammatory mediators that play important roles in eliciting neuroinflammatory responses associated with neurodegenerative diseases. As resveratrol, an antioxidant component of grape, has been reported to exert anti-inflammatory activities on macrophages, we investigated its effects on the production of TNF-alpha (TNF-alpha) and nitric oxide (NO) by lipopolysaccharide (LPS)-activated microglia. Exposure of cultured rat cortical microglia and a mouse microglial cell line N9 to LPS increased their release of TNF-alpha and NO, which was significantly inhibited by resveratrol.