Anti-platelet aggregation of Panax notoginseng triol saponins by regulating GP1BA for ischemic stroke therapy.

BACKGROUND: Panax notoginseng triol saponins (PTS) has been used clinically for ischemic stroke therapy (IST) in China for more than 17 years due to its anti-platelet aggregation and neuro-protective effects, but its mechanism of action is not fully understand. In this study, anti-platelet aggregation-related protein analysis and computer simulations of drug-protein binding interactions were performed to explore the mechanism of the effects of PTS against ischemic stroke in an ischemia reperfusion model. METHODS: Three oral doses of PTS were administered in a model of middle cerebral artery occlusion (MCAO) in rats. Panax notoginseng total saponins (PNS) and a combination of PTS and aspirin were chosen for comparison. To evaluate therapeutic effects and explore possible mechanisms of anti-platelet aggregation, we measured cerebral infarct size and water content in brain tissue, histomorphological changes, expression of related factors (such as arachidonic acid metabolites) and platelet receptors in serum, as well as the binding affinity of PTS for platelet adhesion receptors. RESULTS: Compared with PNS, PTS showed a stronger and more potent anti-platelet aggregation effect in MCAO model rats. The combination of PTS and aspirin could reduce adverse gastrointestinal effects by regulating the TXA2/PGI2 ratio. We demonstrated for the first time that PTS was able to regulate Glycoprotein Ib-α (GP1BA) in a model animal. The binding of ginsenoside Rg1 and GP1BA could form a stable structure. Moreover, PTS could reduce von Willebrand factor (VWF)-mediated platelet adhesion to damaged vascular endothelium, and thus enhance the probability of anti-platelet aggregation and anti-thrombosis under pathological conditions. CONCLUSIONS: Our results showed that GP1BA was closely related to the anti-platelet aggregation action of PTS, which provided new scientific and molecular evidence for its clinical application.

Magnesium Supplementation Attenuates Pulmonary Hypertension via Regulation of Magnesium Transporters.

Pulmonary hypertension (PH) is characterized by profound vascular remodeling and altered Ca2+ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Magnesium ion (Mg2+), a natural Ca2+ antagonist and a cofactor for numerous enzymes, is crucial for regulating diverse cellular functions, but its roles in PH remains unclear. Here, we examined the roles of Mg2+ and its transporters in PH development. Chronic hypoxia and monocrotaline induced significant PH in adult male rats. It was associated with a reduction of [Mg2+]i in PASMCs, a significant increase in gene expressions of Cnnm2, Hip14, Hip14l, Magt1, Mmgt1, Mrs2, Nipa1, Nipa2, Slc41a1, Slc41a2 and Trpm7; upregulation of SLC41A1, SLC41A2, CNNM2, and TRPM7 proteins; and downregulation of SLC41A3 mRNA and protein. Mg2+ supplement attenuated pulmonary arterial pressure, right heart hypertrophy, and medial wall thickening of pulmonary arteries, and reversed the changes in the expression of Mg2+ transporters. Incubation of PASMCs with a high concentration of Mg2+ markedly inhibited PASMC proliferation and migration, and increased apoptosis, whereas a low level of Mg2+ produced the opposite effects. siRNA targeting Slc41a1/2, Cnnm2, and Trpm7 attenuated PASMC proliferation and migration, but promoted apoptosis; and Slc41a3 overexpression also caused similar effects. Moreover, siRNA targeting Slc41a1 or high [Mg2+] incubation inhibited hypoxia-induced upregulation and nuclear translocation of NFATc3 in PASMCs. The results, for the first time, provide the supportive evidence that Mg2+ transporters participate in the development of PH by modulating PASMC proliferation, migration, and apoptosis; and Mg2+ supplementation attenuates PH through regulation of Mg2+ transporters involving the NFATc3 signaling pathway.

Platycodin D alleviates liver fibrosis and activation of hepatic stellate cells by regulating JNK/c-JUN signal pathway.

Liver fibrosis is involved in the progression of most chronic liver diseases. Even though we have made a huge progress in order to understand the pathogenesis of liver fibrosis, however, there is still a lack of productive treatments. Being a traditional Chinese medicine, Platycodin D (PD), an oleanane kind of triterpenoid saponin has been put to extensive use for treating different kinds of illnesses that include not just anti-nociceptive, but also antiviral, anti-inflammatory, and anti-cancer for thousands of years. Nonetheless, there has been no clarification made for its effects on the progression of liver fibrosis. In this manner, we carried out in vitro studies for the purpose of investigating the anti-fibrosis impact of PD. Activation of hepatic stellate cells was evaluated by means of the detection of the proliferation of HSCs and the expression of specific proteins. We discovered the fact that PD had the potential of activating HSCs. Thereafter, we detected the apoptosis and autophagy of the HSCs; as the results suggested, PD induced apoptosis and autophagy of the HSCs. It augmented the expression level of apoptotic proteins that included Bax, Cytochrome C (cyto-c), cleaved caspase3 and cleaved caspase9, in addition to the autophagy relevant proteins, for instance, LC3II, beclin1, Atg5 and Atg9. Further research was carried out for the investigation of the underlying molecular mechanism, and discovered that PD promoted the phosphorylation of JNK and c-Jun. Treating the JNK inhibitor P600125 inhibited the effect of PD, confirming the impact of PD on the regulation of JNK/c-Jun pathway. Thus, we speculated that PD alleviates liver fibrosis and activation of hepatic stellate via promoting phosphorylation of JNK and c-Jun and further altering the autophagy along with apoptosis of HSCs.

Pocahemiketals A and B, two new hemiketals with unprecedented sesquiterpenoid skeletons from Pogostemon cablin.

Pocahemiketals A and B (1 and 2), two novel hemiketal sesquiterpenoids with unprecedented skeletons, were isolated from the essential oil of the aerial parts of Pogostemon cablin. In addition to a bicyclo[3.2.1]-carbon core, 1 and 2 possessed a hemiketal α,ß-unsaturated-γ-lactone moiety. Their structures were determined by extensive spectroscopic analysis, electronic circular dichroism calculation, and single-crystal X-ray diffraction. Compound 2 exhibited significant vasorelaxant activity against phenylephrine-induced contraction of a rat aorta ring with the EC50 value of 16.32µM.

Persistent Mullerian Duct Syndrome: a rare entity with a rare presentation in need of multidisciplinary management

ABSTRACT Main findings: A typical male looking adolescent with a legal female gender assignment presented with haematuria. Investigations led to the diagnosis of Persistent Mullerian Duct Syndrome. The condition is indeed a rare entity that needs a multidisciplinary team management. Case hypothesis: A case of Persistent Mullerian Duct Syndrome undiagnosed at birth because karyotyping was defaulted, thus resulting in a significant impact on the legal gender assignment and psychosocial aspects. Promising future implications: The reporting of this case is important to create awareness due to its rarity coupled with the rare presentation with hematuria as a possible masquerade to menstruation. There were not only medical implications, but also psychosocial and legal connotations requiring a holistic multidisciplinary management.

[Study on constituents of the aerial parts of Pogostemon cablin].

OBJECTIVE: To investigate the chemical constituents of the aerial parts of Pogostemon cablin. METHODS: The constituents were isolated by column chromatography over silica gel, Sephadex LH-20 and C8. Structures were identified by spectroscopic data analysis. RESULTS: Thirteen compounds were obtained and elucidated as patchouli alcohol (1), pogostone (2), friedelin (3), epifriedelinol (4), oleanolic acid (5), methyl oleanolate (6), 5alpha-stigmast-3,6-dione (7), stigmast-4-ene-3-one (8), beta-sitosterol (9), pachypodol (10), retusin (11), (-)-guaiacylglycerol (12) and dibutyl phthalate (13). CONCLUSION: Compounds 6, 7, 8, 12 and 13 are isolated from this genus for the first time.

Downregulation of Cdc6 and pre-replication complexes in response to methionine stress in breast cancer cells.

Methionine and homocysteine are metabolites in the transmethylation pathway leading to synthesis of the methyl-donor S-adenosylmethionine (SAM). Most cancer cells stop proliferating during methionine stress conditions, when methionine is replaced in the growth media by its immediate metabolic precursor homocysteine (Met-Hcy+). Non-transformed cells proliferate in Met-Hcy+ media, making the methionine metabolic requirement of cancer cells an attractive target for therapy, yet there is relatively little known about the molecular mechanisms governing the methionine stress response in cancer cells. To study this phenomenon in breast cancer cells, we selected methionine-independent-resistant cell lines derived from MDAMB468 breast cancer cells. Resistant cells grew normally in Met-Hcy+ media, whereas their parental MDAMB468 cells rapidly arrest in the G 1 phase. Remarkably, supplementing Met-Hcy+ growth media with S-adenosylmethionine suppressed the cell proliferation defects, indicating that methionine stress is a consequence of SAM limitation rather than low amino acid concentrations. Accordingly, mTORC1 activity, the primary effector responding to amino acid limitation, remained high. However, we found that levels of the replication factor Cdc6 decreased and pre-replication complexes were destabilized in methionine-stressed MDAMB468 but not resistant cells. Our study characterizes metabolite requirements and cell cycle responses that occur during methionine stress in breast cancer cells and helps explain the metabolic uniqueness of cancer cells.

Structure-based virtual screening of novel inhibitors of the uridyltransferase activity of Xanthomonas oryzae pv. oryzae GlmU.

N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) catalyzes the formation of UDP-GlcNAc, a fundamental precursor in cell wall biosynthesis. GlmU represents an attractive target for new antibacterial agents. In this study, a theoretical three-dimensional (3D) structure of GlmU from Xanthomonas oryzae pv. oryzae (Xo-GlmU) was generated, and the ligand-receptor interaction was investigated by molecular docking. Then a structure-based virtual screening was performed, three hit compounds were identified as specific inhibitors of the uridyltransferase activity of Xo-GlmU, with IC(50) values in the 0.81-23.21 µM range. Subsequently, the mode-of-inhibition and K(i) values of the three inhibitors were confirmed. The minimum inhibitory concentrations (MICs) of the candidate compounds for X. oryzae pv. oryzae (Xoo) were also determined. The research provided novel chemical scaffolds for antimicrobial drug discovery.

A herbal extract with acetyl-coenzyme A carboxylase inhibitory activity and its potential for treating metabolic syndrome.

Acetyl-coenzyme A carboxylase (ACC) plays a crucial role in fatty acid metabolism, and its inhibition is an effective approach for treating metabolic syndrome. Partially purified ACC from rat liver was used to screen herbs commonly used in Taiwanese folk medicine for ACC inhibitory effects. An ethanol extract of Polygonum hypoleucum Ohwi (EP), the Taiwan tuber fleece flower, was found to have the highest inhibitory activity (half-maximal inhibitory concentration = 30 microg/mL). We then tested the physiologic effects of EP using high-fat (HF) diet-fed C57BL/6J mice. After 4 weeks, body weight and levels of blood glucose, insulin, triacylglycerol, total cholesterol, and leptin were significantly reduced (P < .05) in mice fed a 3% EP-containing HF diet. The EP also improved the glucose tolerance and insulin sensitivity of HF diet-fed mice. In addition, EP at concentrations of 0.0725 and 0.145 mg/mL (2.5- and 5-fold higher than the half-maximal inhibitory concentration) was also effective in decreasing ACC and fatty acid synthase activity and the triacylglycerol content of HepG2 cells incubated in high-glucose (30 mmol/L) medium. These results show that EP, acting by inhibiting ACC activity, is effective in alleviating the symptoms associated with metabolic disease.

Multi-photon laser scanning microscopy using an acoustic optical deflector.

Multi-photon laser scanning microscopes have many advantages over single-photon systems. However, the speed and flexibility of currently available multi-photon microscopes are limited by the use of mechanical mirrors to steer pulsed radiation for fluorophore excitation. Here, we describe the multi-photon adaptation of a confocal microscope that uses an acoustic optical deflector (AOD) for beam steering. AODs are capable of very rapid scanning and, in addition, offer the flexibility of zooming, panning, and being adjustable for slow image acquisition. Because of the highly dispersive nature of AODs, pulsed radiation must be temporally compressed by introducing negative dispersion into the beam path. More critically, pulsed radiation must also be spatially compressed by introducing lateral dispersion into the beam path. This was accomplished by using two prisms in the external beam path and by introducing a third prism element subsequent to the AOD. The end result is an AOD-based multi-photon microscope that is capable of rapid imaging of physiological events as well as slow detection of weakly fluorescent biological samples.