In silico and in vivo study of anti-inflammatory activity of Morinda longissima (Rubiaceae) extract and phytochemicals for treatment of inflammation-mediated diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, the plant Morinda longissima Y.Z.Ruan (Rubiaceae) is used by ethnic people in Vietnam for the treatment of liver diseases and hepatitis.

AIM OF THE STUDY

The study was designed to assess the efficacy of the 95% ethanolic extract of Morinda longissima roots (MLE) in experimental immune inflammation. The phytochemical variation of root extract and the chemical structures of natural compounds were also investigated using HPLC-DAD-HR-MS analysis.

MATERIALS AND METHODS

Three different doses (100, 200, and 300 mg/kg b.w.) of MLE were chosen to determine anti-inflammatory activity. The mice were given orally extracts and monitored their behavior and mortality for 14 days to evaluate acute toxicity. The volume of the paw and the histopathological evaluation were carried out. The polyphenolic phytoconstituents of MLE extract were identified using LC/MS analysis. The anti-inflammatory efficacy in silico and molecular docking simulations of these natural products were evaluated based on their cyclooxygenase (COX)-1 and 2 inhibitory effects.

RESULTS

This investigation showed the 95% ethanolic extract of Morinda longissima roots was found non-toxic up to 2000 mg/kg dose level in an acute study, neither showed mortality nor treatment-related signs of toxicity in mice. Eight anthraquinones and anthraquinone glycosides of Morinda longissima roots were identified by HPLC-DAD-HR-MS analysis. In the in vivo experiments, MLE was found to possess powerful anti-inflammatory activities in comparison with diclofenac sodium. The highest anti-inflammatory activity of MLE in mice was observed at a dose of 300 mg/kg body weight. The in silico analysis showed that seven out the eight anthraquinones and anthraquinone glycosides possess a selectivity index RCOX-2/COX-1 lower than 1, indicating that these compounds are selective against the COX-2 enzyme in the following the order: rubiadin-3-methyl ether < morindone morindone-6-methyl ether < morindone-5-methyl ether < damnacanthol < rubiadin < damnacanthol-3-O-β-primeveroside. The natural compounds with the best selectivity against the COX-2 enzyme are quercetin (9), rubiadin-3-methyl ether (7), and morindone (4), with RCOX2/COX1 ratios of 0.02, 0.03, and 0.19, respectively. When combined with the COX-2 protein in the MD research, quercetin and rubiadin-3-methyl ether greatly stabilized the backbone proteins and ligands.

CONCLUSION

In conclusion, the anthraquinones and ethanolic extract of Morinda longissima roots may help fight COX-2 inflammation. To develop novel treatments for inflammatory disorders linked to this one, these chemicals should be investigated more in the future.

Acetylcholinesterase inhibitory activities of some flavonoids from the root bark of Pinus krempfii Lecomte: in vitro and in silico study

From the root bark of Pinus krempfii Lecomte, four flavonoids were isolated and evaluated for their inhibitory activities against AChE and BChE enzymes in vitro and in silico. Tectochrysin (1) was found to inhibit AChE with an IC50 value of 33.69 ± 2.80 μM. The docking study results also showed agreement with the in vitro test results. All four compounds also showed the best binding affinity for the AChE enzyme, characterised by binding energy (ΔG) values as low as -8.1 to -9.3 kcal/mol, in which, the compound tectochrysin had the best binding affinity for the AChE protein with a ΔG value of -9.329 kcal/mol. Tectochrysin (1) was also bound to the amino acid Phe295 of AChE with a bond length of 2.8 Å, similar to the control dihydrotanshinone-I. Galangin (2) also showed its in vitro inhibitory activity against BChE with an IC50 value of 82.21 ± 2.70 μM. In silico, it also had the best binding energy value of -9.072 kcal/mol with BChE and formed hydrogen bonds with the His438 (2.85 Å) residues of BChE like the positive control (tacrine). The steered molecular dynamics (SMD) simulation results of these two complexes revealed a mechanistic insight that the protein-ligand complexes showed stable trajectories throughout the 20 and 150 ns simulations. Moreover, the drug likeliness suggested that both flavonoids (1 and 2) were expected to be drug-like and have an LD50 toxicity level of 5. This study has contributed new results for drug discovery and the development of substances with neuroprotective effects, especially for the treatment of Alzheimer's disease.Communicated by Ramaswamy H. Sarma.

Laparoscopic treatment for median arcuate ligament syndrome in children: A case report

In median arcuate ligament syndrome (MALS), the median arcuate ligament compresses the celiac trunk and surrounding nerves leading to chronic functional abdominal pain and vague gastrointestinal symptoms. MALS can be effectively treated by dividing the arcuate ligament through open surgery or laparoscopy. This is a rare vascular condition and mostly encountered in adult patients. We hereby report a case of a pediatric patient diagnosed with MALS and treated successfully by laparoscopic approach. An 11-year-old girl presented with severe abdominal cramps for 3 months, accompanied by nonbilious vomiting. Computed tomography (CT) angiography demonstrated clear images of celiac trunk compression suggesting MALS. Laparoscopic surgery to cut the ligament and decompress the celiac artery was performed. The patient was discharged on day 7 postoperative with no recurrence of symptoms after 12 months of follow-up. This report suggested the diagnostic value of CT scan, and the safety and the feasibility of laparoscopic surgical techniques to treat MALS in children.

Giant coronary artery fistula: A case report

Coronary artery fistulas (CAFs) are abnormal connections of coronary arteries where venous circuits bypass the normal capillaries in the myocardium. CAFs are rare, and most patients are asymptomatic. However, CAFs are the most common coronary artery anomalies affecting coronary hemodynamics. While most CAFs are asymptomatic in young patients, symptoms and complications become more frequent with increasing age. CAFs are characterized by variable clinical manifestations based on their size, origin, and drainage site. We describe a 35-year-old woman presenting with the shortness of breath after walking. Despite attempting medical treatment, the patient continued to experience dyspnea, fatigue, fainting the and chest pain episodes. After admission, cardiac imaging was immediately performed and recorded symptomatic CAFs. Percutaneous transcatheter closure treatment was indicated. The patient was discharged with clinical recovery. The treatment of symptomatic CAFs often requires the clear cardiac imaging and endovascular approach to achieve the best clinical results.

Anti-Alzheimer's Activity of Polyphenolic Stilbene-Rich Acetone Fraction of the Oil-Removed Seeds of Passiflora edulis: in Vivo and in Silico Studies

The stilbene-rich acetone fraction in high yield (6.6 %, PEAS) of Passiflora edulis Sims was prepared and evaluated for neuroprotective activity in murine Alzheimer's disease model induced by aluminum chloride and D-galactose. The phytochemical and HPLC-DAD-MS analysis of the polyphenolic stilbene-rich acetone fraction showed that it contained different stilbenes including trans-piceatannol, scirpusins A-B and cassigarol E. The total phenolic content (TPC) of PEAS was 413.87±1.71 mg GAE eqv/g. The neuroprotective activity of PEAS is typically presented in the Morris water maze-reference Spatial Memory test, where the Alzheimer's mice treated at 100 mg/kg (Alz-ED1) and 200 mg/kg (Alz-ED2) spent less than 47 % and 66 % of the time, respectively, than the Alzheimer's model mice (Alz). Two simple stilbenes, trans-piceatannol and trans-resveratrol, showed selectively inhibitory activity in silico against acetylcholinesterase (AChE). Two stilbene dimers, cassigarol E and scirpusin A, exhibited low nanomolar inhibitory potential against AChE and butyrylcholinesterase (BChE), significantly lower than those of the positive control, donepezil and tacrine. These findings suggest that the stilbenes from P. edulis seeds, particularly the stilbene dimers, warrant further investigation as potential neuroprotective candidates in the prevention of cognitive deficits associated with Alzheimer's disease.

A Complicated Case Report of Coronary Artery Fistula

Background

Coronary artery fistulas (CAFs), also, known as coronary arteriovenous malformation, are aberrant connections between coronary arteries and other structures, such as other artery branches or heart chambers. CAFs are infrequent and asymptomatic in young patients, but symptoms and complications become more frequent with age. CAFs can affect hemodynamic parameters and lead to complications, such as myocardial ischemia, heart failure, arrhythmia, and infective endocarditis.

Objective

The aim of this article was to present a typical CAF case with severe symptoms who underwent successful embolization to resolve their symptoms.

Case presentation

A 50-year-old Vietnamese male visited our cardiac outpatient clinic (S.I.S General Hospital, Can Tho, Vietnam) because of exertional dyspnea and chest pain. Signs of congestive heart failure and abnormal murmur were not presented on chest auscultation. Diagnostic digital subtraction angiography was performed to determine the detailed angioarchitecture of the CAF, revealing a fistulous connection between the left anterior descending artery (LAD) and the LV chamber through an aneurysm. In addition, the RCA measured 7 mm in diameter with a fistula (16 × 9 mm) draining into an aneurysm and then terminating into the LV chamber. The patient had an RCA aneurysm with a fistula into the LV. It was treated successfully by closing the fistula with a vascular plug. Access to the fistula was complex and difficult because of complications due to the CAF. After the procedure, the patient had no chest pain or shortness of breath and was discharged after three days. After six months, he was taking dual antiplatelet therapy and antihypertensive medications and felt better. We performed contrast computed tomography (CT) to examine the fistula after a year, which showed the successful closure of the fistula without any relevant alteration in the coronary artery.

Conclusion

CAF closure is indicated if patients have symptoms or secondary complications, and percutaneous closure is a safe and effective method to manage CAF. A CAF is rare and does not have specific symptoms, making it difficult to diagnose. Most patients are asymptomatic and have serious recent complications. Currently, the percutaneous transcatheter method is popular because it is noninvasive and successful in most patients.

Vietnamese Dalbergia tonkinensis: A Promising Source of Mono- and Bifunctional Vasodilators

Hypertension is a risk factor for cardiovascular diseases, which are the main cause of morbidity and mortality in the world. In the search for new molecules capable of targeting K_Ca1.1 and Ca_V1.2 channels, the expression of which is altered in hypertension, the in vitro vascular effects of a series of flavonoids extracted from the heartwoods, roots, and leaves of Dalbergia tonkinensis Prain, widely used in traditional medicine, were assessed. Rat aorta rings, tail artery myocytes, and docking and molecular dynamics simulations were used to analyse their effect on these channels. Formononetin, orobol, pinocembrin, and biochanin A showed a marked myorelaxant activity, particularly in rings stimulated by moderate rather than high KCl concentrations. Ba²⁺ currents through Ca_V1.2 channels (I_Ba1.2) were blocked in a concentration-dependent manner by sativanone, 3′-O-methylviolanone, pinocembrin, and biochanin A, while it was stimulated by ambocin. Sativanone, dalsissooside, and eriodictyol inhibited, while tectorigenin 7-O-[β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside], ambocin, butin, and biochanin A increased I_KCa1.1. In silico analyses showed that biochanin A, sativanone, and pinocembrin bound with high affinity in target-sensing regions of both channels, providing insight into their potential mechanism of action. In conclusion, Dalbergia tonkinensis is a valuable source of mono- and bifunctional, vasoactive scaffolds for the development of novel antihypertensive drugs.

Soluble epoxide hydrolase inhibitors from Docynia indica (Wall.) Decne

Nine bioactive compounds, including one new dihydroisocoumarin glycoside, 3S-thunberginol C 6-O-β-D-glucopyranoside (1a/1b), were isolated by chromatographic separation from the fruits of the Vietnamese medicinal plant Docynia indica (Wall.) Decne. 3S-thunberginol C 6-O-β-D-glucopyranoside was determined as a mixture of boat-like conformers based on NMR evidence and density functional theory (DFT) calculations. The in vitro inhibition of soluble epoxide hydrolase (sEH) by the isolated compounds was comparable to that of AUDA (positive control), yielding IC₅₀ values ranging from 10.0 ± 0.6 to 88.4 ± 0.2 µM. Among isolated compounds, 3-methoxy-4-hydroxy-benzoic acid (7) and 2',6'-dihydroxy 3',4'-dimethoxychalcone (9) were identified as a potent inhibitor of sEH, with IC₅₀ values of 19.3 ± 2.2 and 10.0 ± 0.6 mM, respectively. These results suggest that the fruits of D. indica may be useful as daily supplements for the prevention of cardiovascular and other sEH-related diseases.[Formula: see text].

Reversal of Deep Effect of Rocuronium by Sugammadex or Neostigmine after Abdominal Laparoscopic Surgery: A Single Center Experience in Vietnam

BACKGROUND: Using sugammadex allows to quickly reverse deep neuromuscular blockade with rocuronium in laparoscopic surgery, which results in great benefits during and after surgery by minimizing the problem of postoperative residual curarization. AIM: The aims of this study are comparing the efficacy of reversing neuromuscular blockade between sugammadex and neostigmine and evaluating its unwanted effects after laparoscopic abdominal surgery. METHODS: Subject of this prospective clinical comparative trial was patients who underwent abdominal laparoscopic surgery at 103 Military Hospital from October 2017 to October 2018. Eighty-four patients suffering from abdominal laparoscopic surgery under deep neuromuscular blockade were enrolled and divided randomly into two groups with 42 patients in each: Group N used neostigmine for neuromuscular blockade reversal and Group S applied sugammadex. At the end of surgery, neuromuscular blockade was reversed with either sugammadex or neostigmine. RESULTS: The reversal time to achieve train-of-four ratio >0.9 in the sugammadex group was 2.42 ± 0.58 min, which was shorter than in the neostigmine group (11.83 ± 2.19 min) (p < 0.05). The time until extubation in the sugammadex group was 3.69 ± 0.67 min, which was shorter than in the neostigmine group 11.90 ± 2.22 min (p < 0.05). Reversal with sugammadex resulted in statistical significance of less sputum production (0% vs. 11.9%), dry mouth (0% vs. 28.57%), headache (2.38% vs. 7.14%), and nausea (4.76% vs. 14.28%) compared with neostigmine. However, 26.19% of patients in the neostigmine group presented bradycardia, whereas the concurrent administration of atropine in the neostigmine group resulted in increased heart rate. CONCLUSION: Sugammadex reversed neuromuscular blockade more rapidly and effectively than neostigmine in abdominal laparoscopic surgeries. The unwanted effects of sugammadex group were fewer than neostigmine group.

Vasorelaxing Activity of R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol from Dalbergia tonkinensis: Involvement of Smooth Muscle CaV1.2 Channels

Dalbergia species heartwood, widely used in traditional medicine to treat various cardiovascular diseases, might represent a rich source of vasoactive agents. In Vietnam, Dalbergia tonkinensis is an endemic tree. Therefore, the aim of the present work was to investigate the vascular activity of R-(-)-3'-hydroxy-2,4,5-trimethoxydalbergiquinol isolated from the heartwood of D. tonkinensis and to provide circular dichroism features of its R absolute configuration. The vascular effects of R-(-)-3'-hydroxy-2,4,5-trimethoxydalbergiquinol were assessed on the in vitro mechanical activity of rat aorta rings, under isometric conditions, and on whole-cell Ba²⁺ currents through Ca_V1.2 channels (I_Ba1.2) recorded in single, rat tail main artery myocytes by means of the patch-clamp technique. R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol showed concentration-dependent, vasorelaxant activity on both endothelium-deprived and endothelium intact rings precontracted with the α ₁ receptor agonist phenylephrine. Neither the NO (nitric oxide) synthase inhibitor N^ω-nitro-L-arginine methyl ester nor the cyclooxygenase inhibitor indomethacin affected its spasmolytic activity. R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol-induced vasorelaxation was antagonized by (S)-(-)-Bay K 8644 and unaffected by tetraethylammonium plus glibenclamide. In patch-clamp experiments, R-(-)-3'-hydroxy-2,4,5-trimethoxydalbergiquinol inhibited I_Ba1.2 in a concentration-dependent manner and significantly decreased the time constant of current inactivation. R-(-)-3'-Hydroxy-2,4,5-trimethoxydalbergiquinol likely stabilized the channel in its closed state, as suggested by molecular modelling and docking simulation to the Ca_V1.2 channel α _1c subunit. In conclusion, D. tonkinensis species may represent a source of agents potentially useful for the development of novel antihypertensive drugs.

Serine protease inhibitors and activators from Dalbergia tonkinensis species

The vulnerable plant Dalbergia tonkinensis Prain is a rare species in Vietnam. In the course of our studies on biologically active plants, we performed serine protease enzyme screenings. The results suggest that at concentrations of 25-250 ng/mL, methanol extracts of leaf and root, root ethanol extract and its dichloromethane fraction, and heartwood water decoction extract can serve as useful sources to stimulate trypsin enzyme activity. In addition, water decoction extracts of leaf and stem bark may explain unknown ethno-pharmacology due to the high inhibitory effects in enzyme assays using trypsin, chymotrypsin, and elastase. Among 23 isolated compounds and two semi-synthetic derivatives tested, quercetin (17) inhibits the activities of trypsin and chymotrypsin with IC₅₀ 9.7 µM. Flavonoids categorized as flavanone, isoflavanone, flavone, isoflavone, pretocarpan, aurone, and neoflavanone demonstrated variable activities. Several substitutions are closely correlated with protease actions, including hydroxylation at C-3 and C-3' in flavone and C-5 and C-3' in isoflavone, hydroxylation at C-3, C-5 and C-3', carboxylation at C-6 and C-8, and 7-substitution in flavanone; 7-substitution and methoxylation at C-3' in isoflavanone; and lactone ring opening in neoflavanone. In the assessment of casein cleavage, at a dose of 25 ng/mL, leaf water decoction extract demonstrates an inhibitory effect on casein cleavage by trypsin, whereas ethanol and methanol extracts of the root caused activation.

Preemptive analgesia after lumbar spine surgery by pregabalin and celecoxib: a prospective study

Objective

To evaluate the preemptive analgesic effect of combination pregabalin with celecoxib for lumbar spine surgery.

Methods

A prospective, randomized study was conducted among 60 lumbar spine surgery patients and divided into two groups. Postoperative pain relief was achieved with intravenous patient-controlled analgesia with morphine. The preemptive analgesia group received oral pregabalin (150 mg) and celecoxib (200 mg) 2 hrs before surgery, and the control group received a placebo. Pain was assessed by visual analogue scale (VAS). Side effects and morphine consumption were monitored until 48 hrs after surgery.

Results

VAS score at rest and during movement was statistically significantly lower in the preemptive analgesia group at most time points (p<0.05). Morphine consumption was significantly lower in the preemptive analgesia group compared with control group in the 24 first hours (29.03±4.38 mg vs 24.43±4.94) and 48 hrs (52.23±9.57 mg vs 44.20±10.21 mg), p<0.05. Hemodynamics, respiratory rate, and SpO₂ were similar for both groups. The sedation score was only statistically significant at H8 time point. The incidence of nausea/vomiting in the preemptive group did not statistically differ from the control group.

Conclusion

Preoperative administration of pregabalin combined with celecoxib had a good preemptive analgesia effect and reduced intravenous morphine consumption after lumbar spine surgery. Side effects were mild and transient.

Successful intralipid-emulsion treatment of local anesthetic systemic toxicity following ultrasound-guided brachial plexus block: case report

Background

Local anesthetic systemic toxicity (LAST) is a life-threatening complication that may follow application of LAs through various routes. Despite increasing usage of LA techniques in a large number of health-care settings, contemporary awareness of LAST and understanding of its management are inadequate.

Case presentation

We report two cases who suffered LAST following brachial plexus block for surgery on the upper extremity. The first patient received an ultrasound-guided supraclavicular block with 300 mg lidocaine (6 mg/kg) and 50 mg ropivacaine (1 mg/kg) in 25 mL without epinephrine, and the second patient received an ultrasound guided interscalene block with 200 mg lidocaine (4.5 mg/kg) and 45 mg ropivacaine (1 mg/kg) supplemented with epinephrine 1:200,000. Both patients presented with symptoms of central nervous and respiratory system depression, the first roughly 10 minutes after injection, and the second immediately after withdrawal of the needle. In both cases, thorough recovery was obtained using lipid-emulsion therapy.

Conclusion

The complication of LAST following ultrasound-guided brachial plexus block could be treated successfully applying the American Society of Regional Anesthesia and Pain Medicineprotocol of intravenous administration of lipid emulsion.

Patient-controlled paravertebral analgesia for video-assisted thoracoscopic surgery lobectomy

Background

Paravertebral block has been proven to be an efficient method to provide post-thoracotomy pain management. This study aimed to compare patient-controlled paravertebral analgesia (PCPA) and intravenous patient-controlled analgesia (IVPCA) in terms of analgesic efficiency, respiratory function, and adverse effects after video-assisted thoracoscopic surgery (VATS) lobectomy.

Patients and methods

The prospective randomized trial study was carried out on 60 patients who underwent VATS lobectomy (randomly allocated 30 patients in each group). In the PCPA group, an initial dose of 0.3 mL/kg of 0.125% bupivacaine with fentanyl 2 µg/mL was administered, followed by a 3 mL/h continuous infusion with patient-controlled analgesia (2 mL bolus, 10-minute lockout interval, 25 mL/4 h limit). In the IVPCA group with morphine 1 mg/mL solution, an infusion device was programmed to deliver a 1.0 mL demand bolus with no basal infusion rate, with a 10-minute lockout interval and a maximum of 20 mL/4 h period. Postoperative pain was assessed by visual analog scale at rest and on coughing. Arterial blood gas and spirometry were monitored and recorded for the first 3 postoperative days. Side effects to include were also recorded.

Results

The PCPA group had statistically significant lower pain scores (P<0.0001) at rest at all times. Lower pain scores on coughing were statistically significant in PCPA group in the first 4 hours. Postoperative spirometry showed that both the groups had comparable recovery trajectories for their pulmonary function. Arterial blood gas analysis showed pH and PaCO₂ were in a normal range in both the groups. The incidence of headache was higher in the IVPCA group (13.3% vs 0%; P=0.038).

Conclusion

PCPA effectively managed pain after VATS lobectomy, with lower pain scores, similar respiratory function, and fewer side effects than standard IVPCA treatment.

In silico screening of anthraquinones from Prismatomeris memecyloides as novel phosphodiesterase type-5 inhibitors (PDE-5Is)

OBJECTIVE

Prismatomeris memecyloides Craib (Rubiaceae) is a medicinal plant traditionally used by ethnic minorities in Vietnam for the treatment of erectile dysfunction (ED). The aim of this study was to investigate the chemical compositions and screen in silico its possible inhibitory effect against PDE-5 which reduced cyclic guanosine-3',5'-monophosphate (cGMP) levels and indirectly caused the male ED.

METHODS

Separation of natural compounds were carried out on chromatographic column with silica gel or reversed phase materials, eluting with different solvent gradients. The structures of all isolated compounds were elucidated on the basis of spectroscopic data (HR-MS, 1D/2D-NMR). Docking simulation study of compound (1-7) was performed by using flexible side chains protocol based on Iterated Local Search Global Optimizer Algorithm of AutoDock/Vina v.1.1.2. Pharmacokinetic parameters and toxicity prediction were also calculated by appropriate softwares.

RESULTS

From the methanol extract of roots of P. memecyloides collected in Vietnam, seven compounds including four anthraquinone/one anthraquinone glycoside namely damnacanthal (1), lucidin-ω-methyl ether (2), 3-methylalizarin (3), rubiadin-3-methyl ether (4), and 1-O-methylrubiadin 3-O-primeveroside (5) along with two iridoid glucosides, asperulosidic acid (6) and aitchisonide A (7) were isolated. The molecular modeling results showed that 5 anthraquinone compounds possess the lowest binding energies to PDE-5. The anthraquinone glucoside 1-O-methylrubiadin 3-O-primeveroside (5) potentially inhibited PDE-5 similarly to commercial PDE-5Is sildenafil (SLD) and tadalafil (TLD). Calculated pharmacokinetic results like pIC_50,pred; miLogP, TPSA, enzyme inhibitory of anthraquinone glucoside (5) were similar and even higher to those of the commercial PDE-5 inhibitors. Especially the predictive toxicity of 1-O-methylrubiadin 3-O-primeveroside (5) was even lower than those of SLD and TLD.

CONCLUSION

This is the first study to find a scientific-based evidence for the ethnic use of P. memecyloides as medicinal plant for the treatment of ED. The result indicates that the anthraquinones (damnacanthal (1), lucidin-ω-methyl ether (2), 3-methylalizarin (3) and rubiadin-3-methyl ether (4)), especially anthraquinone glycoside (1-O-methylrubiadin 3-O-primeveroside (5)) are compounds of potential novel drug class for the ED treatment.

New Records of Potent In-Vitro Antidiabetic Properties of Dalbergia tonkinensis Heartwood and the Bioactivity-Guided Isolation of Active Compounds

Alpha-glucosidase inhibitory activity has been commonly used for the evaluation of antidiabetic property in vitro. The aim of this study is to investigate and characterize Dalbergia tonkinensis as a potential source of antidiabetic compounds. The screening of the active parts used, such as trunk bark, heartwood, and the leaves of Dalbergia tonkinensis indicated that all these extracted parts used with methanol demonstrated potent α-glucosidase inhibitory activity. The in vitro antidiabetic property of Dalbergia tonkinensis was notably recorded for the first time and showed activity (EC₅₀ = 0.17–0.78 mg/mL) comparable to those of reported potent herbal extracts (EC₅₀ = 0.25–4.0 mg/mL) and higher activity than that of acarbose, a commercial antidiabetic drug (EC₅₀ = 1.21 mg/mL). The stability tests revealed that the heartwood of Dalbergia tonkinensis extract (HDT) possesses high pH stability with relative activity in the range of 80–98%. Further bioassay-guided purification led to the isolation of 2 active compounds identified as sativanone and formononetin from the ethyl acetate fraction and water fraction of HDT, respectively. These α-glucosidase inhibitors (aGIs) show promising inhibition against various types of α-glucosidases. Remarkably, these inhibitors were determined as new mammalian aGIs, showing good effect on rat α-glucosidase. The results suggest that Dalbergia tonkinensis is a potent source of aGIs and suggest promise in being developed as functional food with antidiabetic efficacy. The results of this study also enrich our knowledge concerning current biological activity and constituents of Dalbergia tonkinensis species.

Antimicrobial Activity of the Constituents of Dalbergia tonkinensis and Structural-Bioactive Highlights

The vulnerable plant Dalbergia tonkinensis Prain, is a rare species, native to Vietnam. Phytochemical investigations and biological evaluations of this species are quite limited. Antimicrobial screening has suggested that, at the low dose of 1.0 mg/mL, the methanol extracts of the leaf, stem bark, and root, as well as chloroform fraction of heartwood can serve as useful sources against seven gram-positive skin microbacteria, Bacillus cereus (ATCC27522), Escherichia coli (JM109), Staphylococcus aureus (ATCC25923), Staphylococcus epidermidis (ATCC14990), Streptococcus pneumonia (ATCC49619), Streptococcus pyogenes (ATCC12344), and Vibrio parahaemolyticus (RIMD2210010), and four oral gram-positive microbacteria Streptococcus mutans (ATCC 25175), Streptococcus mitis (ATCC903), Streptococcus sobrinus (ATCC 33478), and Porphyromonas gingivalis (ATCC33277), with an inhibitory percentage of 60-80% growth for several strains Bacillus cereus, Escherichia coli, and Streptococcus pneumonia. We further assessed antimicrobial activities of the enriched diverse flavonoids from chloroform fraction of its heartwood. Extensive structural activity relationship studies showed structure function closely related to the antimicrobial activity, in which methoxylation at C-2’, and 4’ in isoflavanones, hydroxylation at C-3’ in flavones, substitution at C-5 in isoflavones, and lactone opened ring in neoflavonoids were found to increase the effective inhibitions. In the second antimicrobial assessment, the isolated flavonoid liquiritigenin showed the MIC values of 50, and 100 μg/mL against the microbacterial strains Staphylococcus aureus subsp. aureus (ATCC 11632), and Aspergillus niger (439), respectively, whereas the MIC value of 100 μg/mL was assignable to biochanin A against microbacterium Staphylococcus aureus subsp. aureus.

Two New Carboxyethylflavanones from the Heartwood of Dalbergia tonkinensis and Their Antimicrobial Activities

Two new carboxyethylflavanone derivatives, (2 S)-8-carboxyethylnarigenin (2) and (2 S)-6,8-dicarboxyethylpinocembrin (3) were isolated from the heartwood of Dalbergia tonkinensis Prain, along with four known compounds 1, and 4-6. The chemical structures of two new compounds 2 and 3 were elucidated based on analyses of the spectroscopic data, including 1D and 2D NMR, HR-ESI-MS, IR, UV, and CD spectroscopies. By carrying out antimicrobial assay, CH3OH and CHCl3 fractions exhibited weak MIC value at 200 μg/mL against filamentous fungus A. niger (439), whereas the known flavanone 1 and the new carboxyethylflavanone 2 had MIC at 100 μg/mL.

Tobacco Control Policies in Vietnam: Review on MPOWER Implementation Progress and Challenges

In Vietnam, the WHO Framework Convention on Tobacco Control (WHO FCTC) took effect in March 2005 while MPOWER has been implemented since 2008. This paper describes the progress and challenges of implementation of the MPOWER package in Vietnam. We can report that, in term of monitoring, Vietnam is very active in the Global Tobacco Surveillance System, completing two rounds of the Global Adult Tobacco Survey (GATS) and three rounds of the Global Youth Tobacco Survey (GYTS). To protect people from tobacco smoke, Vietnam has issued and enforced a law requiring comprehensive smoking bans at workplaces and public places since 2013. Tobacco advertising and promotion are also prohibited with the exception of points of sale displays of tobacco products. Violations come in the form of promotion girls, corporate social responsibility activities from tobacco manufacturers and packages displayed by retail vendors. Vietnam is one of the 77 countries that require pictorial health warnings to be printed on cigarette packages to warn about the danger of tobacco and the warnings have been implemented effectively. Cigarette tax is 70% of factory price which is equal to less than 45% of retail price and much lower than the recommendation of WHO. However, Vietnam is one of the very few countries that require manufacturers and importers to make "compulsory contributions" at 1-2% of the factory price of cigarettes sold in Vietnam for the establishment of a Tobacco Control Fund (TCF). The TCF is being operated well. In 2015, 67 units of 63 provinces/cities, 22 ministries and political-social organizations and 6 hospitals received funding from TCF to implement a wide range of tobacco control activities. Cessation services have been starting with a a toll-free quit-line but need to be further strengthened. In conclusion, Vietnam has constantly put efforts into the tobacco control field with high commitment from the government, scientists and activists. Though several remarkable achievements have been gained, many challenges remain. To overcome those challenges, implementation strategies that take into account the contextual factors and social determinants of tobacco use in Vietnam are needed.

Potential Impact of Graphic Health Warnings on Cigarette Packages in Reducing Cigarette Demand and Smoking-Related Deaths in Vietnam

Two years after implementation of the graphic health warning intervention in Vietnam, it is very important to evaluate the intervention's potential impact. The objective of this paper was to predict effects of graphic health warnings on cigarette packages, particularly in reducing cigarette demand and smoking-associated deaths in Vietnam. In this study, a discrete choice experiment (DCE) method was used to evaluate the potential impact of graphic tobacco health warnings on smoking demand. To predict the impact of GHWs on reducing premature deaths associated with smoking, we constructed different static models. We adapted the method developed by University of Toronto, Canada and found that GHWs had statistically significant impact on reducing cigarette demand (up to 10.1% through images of lung damage), resulting in an overall decrease of smoking prevalence in Vietnam. We also found that between 428,417- 646,098 premature deaths would be prevented as a result of the GHW intervention. The potential impact of the GHW labels on reducing premature smoking-associated deaths in Vietnam were shown to be stronger among lower socio-economic groups.

Anti-HIV diphyllin glycosides from Justicia gendarussa

In a search for new anti-HIV active leads from over several thousands of plant extracts, we have identified a potent plant lead. The active plant is determined as Justicia gendarussa (Acanthaceae), a medicinal plant that has been used for the treatment of injury, arthritis and rheumatism in Asia including China. Our bioassay-guided fractionation of the methanol extract of the stems and barks of the plant led to the isolation of two anti-HIV compounds, justiprocumins A and B. The compounds are identified as new arylnaphthalide lignans (ANL) glycosides. We further determined that the ANL glycosides are the chemical constituents that contribute to the anti-HIV activity of this plant. Justiprocumin B displayed potent activity against a broad spectrum of HIV strains with IC₅₀ values in the range of 15-21 nM (AZT, IC₅₀ 77-95 nM). The compound also displayed potent inhibitory activity against the NRTI (nucleoside reverse transcriptase inhibitor)-resistant isolate (HIV-1_1617-1) of the analogue (AZT) as well as the NNRTI (non-nucleoside reverse transcriptase inhibitor)-resistant isolate (HIV-1_N119) of the analogue (nevaripine).

Inhibitory Components from Glycosmis stenocarpa on Pepper Mild Mottle Virus

The goal of this study was to identify a source of natural plant compounds with inhibitory activity against pepper mild mottle virus (PMMoV). We showed, using a half-leaf assay, that murrayafoline-A (1) and isomahanine (2) isolated from the aerial parts of Glycosmis stenocarpa have inhibitory activity against PMMoV through curative, inactivation, and protection effects. Using a leaf-disk assay, we confirmed that 2 inhibited virus replication in Nicotiana benthamiana. Using electron microscopy, we found that a mixture of the virus with 2 resulted in damage to the rod-shaped virus.

Litsea Species as Potential Antiviral Plant Sources

Litsea verticillata Hance (Lauraceae), a Chinese medicine used to treat swelling caused by injury or by snake bites, was the first plant identified by our National Institutes of Health (NIH)-funded International Cooperative Biodiversity Group (ICBG) project to exhibit anti-HIV activities. From this plant, we discovered a class of 8 novel litseane compounds, prototypic sesquiterpenes, all of which demonstrated anti-HIV activities. In subsequent studies, 26 additional compounds of different structural types were identified. During our continuing investigation of this plant species, we identified two new litseanes, litseaverticillols L and M, and a new sesquiterpene butenolide, litseasesquibutenolide. Litseaverticillols L and M were found to inhibit HIV-1 replication, with an IC[Formula: see text] value of 49.6[Formula: see text][Formula: see text]M. To further determine the antiviral properties of this plant, several relatively abundant isolates, including a litseane compound, two eudesmane sesquiterpenes and three lignans, were evaluated against an additional 21 viral targets. Lignans 8 and 9 were shown to be active against the Epstein-Barr Virus (EBV), with EC[Formula: see text] values of 22.0[Formula: see text][Formula: see text]M ([Formula: see text]) and 16.2[Formula: see text][Formula: see text]M ([Formula: see text]), respectively. Since many antiviral compounds have been discovered in L. verticillata, we further prepared 38 plant extracts made from the different plant parts of 9 additional Litsea species. These extracts were evaluated for their anti-HIV and cytotoxic activities, and four of the extracts, which ranged across three different species, displayed 97-100% inhibitory effects against HIV replication without showing cytotoxicity to a panel of human cell lines at a concentration of 20 μg/mL.

Changes in knowledge, attitude and involvement of fathers in supporting exclusive breastfeeding: a community-based intervention study in a rural area of Vietnam

OBJECTIVES

To test the hypotheses of positive changes of fathers' knowledge, attitude and involvement in supporting exclusive breastfeeding (EBF) after receiving breastfeeding education materials and counseling services.

METHODS

A quasi-experimental, pre-test-post-test, non-equivalent control group design was used. At baseline, 251 and 241 pregnant women and their husbands were enrolled into the intervention and control groups, respectively. The 1-year intervention targeting fathers included mass media, game show-style community events, group and individual counseling at health facilities and home visits.

RESULTS

Compared to fathers in the control group, fathers in the intervention group had higher BF knowledge scores and higher attitude scores reflecting more positive attitudes toward early initiation of BF and 6 months EBF. Fathers in the intervention group were also more likely to report active involvement in supporting mothers to practice EBF during antenatal and postpartum periods.

CONCLUSIONS

The community-based education model should be maintained and considered for conducting further test in wider application to mobilize fathers in supporting EBF.

Relative Importance of Different Attributes of Graphic Health Warnings on Tobacco Packages in Viet Nam

Graphic health warnings (GHW) on tobacco packages have proven to be effective in increasing quit attempts among smokers and reducing initial smoking among adolescents. This research aimed to examine the relative importance of different attributes of graphic health warnings on tobacco packages in Viet Nam. A discrete choice experimental (DCE) design was applied with a conditional logit model. In addition, a ranking method was used to list from the least to the most dreadful GHW labels. With the results from DCE model, graphic type was shown to be the most important attribute, followed by cost and coverage area of GHW. The least important attribute was position of the GHW. Among 5 graphic types (internal lung cancer image, external damaged teeth, abstract image, human suffering image and text), the image of lung cancer was found to have the strongest influence on both smokers and non-smokers. With ranking method, the image of throat cancer and heart diseases were considered the most dreadful images. GHWs should be designed with these attributes in mind, to maximise influence on purchase among both smokers and non-smokers.

PHENOLIC COMPOUNDS FROM CALLISTEMON CITRINUS LEAVES AND STEMS

In the search for bioactive constituents from Vietnamese plants,  the leaves and stems of Callistemon citrinus (Curtis) Skeels were selected for chemical investigation. Phytochemical analysis of plant led to the isolation of eight phenolic compounds including two flavonoids (eucalyptine (1) and 8-demethyleucalyptine (2)), two alcohols (blumenol A (3), n-tetratriacontanol (4)), three benzoic acid derivatives (acid gallic (5), methyl gallate (6) protocatechuic acid (7)), one sterol (b-sitosterol (8)), and along with one sesquiterpene (2,6,10-bisabolatriene (9)). The structures of the natural compounds were determined by spectroscopic evidences including 1D- and 2D-NMR and ESI-MS.

Functional, electrophysiological and molecular docking analysis of the modulation of Cav 1.2 channels in rat vascular myocytes by murrayafoline A

BACKGROUND AND PURPOSE

The carbazole alkaloid murrayafoline A (MuA) enhances contractility and the Ca(2+) currents carried by the Cav 1.2 channels [ICa1.2 ] of rat cardiomyocytes. As only few drugs stimulate ICa1.2 , this study was designed to analyse the effects of MuA on vascular Cav 1.2 channels.

EXPERIMENTAL APPROACH

Vascular activity was assessed on rat aorta rings mounted in organ baths. Cav 1.2 Ba(2+) current [IBa1.2 ] was recorded in single rat aorta and tail artery myocytes by the patch-clamp technique. Docking at a 3D model of the rat, α1c central pore subunit of the Cav 1.2 channel was simulated in silico.

KEY RESULTS

In rat aorta rings MuA, at concentrations ≤14.2 μM, increased 30 mM K(+) -induced tone and shifted the concentration-response curve to K(+) to the left. Conversely, at concentrations >14.2 μM, it relaxed high K(+) depolarized rings and antagonized Bay K 8644-induced contraction. In single myocytes, MuA stimulated IBa1.2 in a concentration-dependent, bell-shaped manner; stimulation was stable, incompletely reversible upon drug washout and accompanied by a leftward shift of the voltage-dependent activation curve. MuA docked at the α1C subunit central pore differently from nifedipine and Bay K 8644, although apparently interacting with the same amino acids of the pocket. Neither Bay K 8644-induced stimulation nor nifedipine-induced block of IBa1.2 was modified by MuA.

CONCLUSIONS AND IMPLICATIONS

Murrayafoline A is a naturally occurring vasoactive agent able to modulate Cav 1.2 channels and dock at the α1C subunit central pore in a manner that differed from that of dihydropyridines.

Murrayafoline A Induces a G0/G1-Phase Arrest in Platelet-Derived Growth Factor-Stimulated Vascular Smooth Muscle Cells

The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through G₀/G₁ to S phase of the cell cycle, as measured by [³H]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at G₀/G₁ phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

Chemical constituents of Miliusa balansae leaves and inhibition of nitric oxide production in lipopolysaccharide-induced RAW 264.7 cells

Methanolic extract of Miliusa balansae Finet et Gagnep exerts an anti-inflammatory effect via inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophage cells. Three new megastigmane glycosides, milbasides A-C (1-3), together with fifteen known compounds (4-18), were isolated from the active fraction. Their chemical structures were elucidated using extensive spectroscopic analyses, including 1D and 2D NMR, HR ESI MS, and CD analysis, as well as comparison with previously reported data. Compounds 1-3, 11 and 14 (20.0 μM) showed potent inhibitory activities with inhibition values of 98.5 ± 1.6%, 90.9 ± 7.8%, 84.8 ± 3.5%, 91.5 ± 8.7%, and 91.8 ± 2.7%, respectively. Our results suggest that megastigmane glycosides from M. balansae leaves may be used to treat inflammatory diseases.

Vasorelaxing activity of two coumarins from Murraya paniculata leaves

In the search for novel chemical scaffolds leading to potential antihypertensive agents, the methanol extract of Murraya paniculata leaves was assessed for its effects on isolated rat aorta rings. The vasorelaxing effect of the chloroform fraction of the methanol plant extract was the most potent for its vasorelaxing activity on rat aorta rings contracted by 60 mM K(+) (K60). Two coumarins were isolated from the chloroform fraction: the novel kimcuongin (1) and the known murracarpin (2). Their structures were determined from spectroscopic evidences including (1)H- and (13)C-NMR, correlation spectroscopy (COSY), nuclear Overhauser effect spectroscopy (NOESY), heteronuclear multiple bond correlation (HMBC), heteronuclear single quantum correlation (HSQC), and high resolution mass spectrometry (HR-MS). Kimcuongin and, to a lesser extent, murracarpin, showed vasorelaxing activity with IC50 values of 37.7 µM and 139.3 µM, respectively. The coumarins kimcuongin and murracarpin may thus represent a novel class of vasodilators of natural source.

In vitro vasoactivity of zerumbone from Zingiber zerumbet

The sesquiterpene zerumbone, isolated from the rhizome of Zingiber zerumbet Sm., besides its widespread use as a food flavouring and appetiser, is also recommended in traditional medicine for the treatment of several ailments. It has attracted great attention recently for its effective chemopreventive and therapeutic effects observed in various models of cancer. To assess the zerumbone safety profile, a pharmacology study designed to flag any potential adverse effect on vasculature was performed. Zerumbone was tested for vasorelaxing activity on rat aorta rings and for L-type Ba(2+) current blocking activity on single myocytes isolated from the rat-tail artery. The spasmolytic effect of zerumbone was more marked on rings stimulated with 60 mM than with 30 mM K(+) (IC50 values of 16 µM and 102 µM, respectively). In the presence of 60 mM K(+), zerumbone concentration-dependently inhibited the contraction induced by the cumulative additions of Ca(2+), this inhibition being inversely related to the Ca(2+) concentration. Phenylephrine-induced contraction was inhibited by the drug, though less efficiently and independently of the presence of an intact endothelium, without affecting Ca(2+) release from the intracellular stores. Zerumbone inhibited the L-type Ba(2+) current (estimated IC50 value of 458.7 µM) and accelerated the kinetics of current decay. In conclusion, zerumbone showed an overall weak in vitro vasodilating activity, partly attributable to the blocking of the L-type Ca(2+) channel, which does not seem to represent, however, a serious threat to its widespread use.

Antiplatelet action of indirubin-3'-monoxime through suppression of glycoprotein VI-mediated signal transduction: a possible role for ERK signaling in platelets

We investigated the antiplatelet activity of indirubin-3'-monoxime (I3O) and the underlying mechanisms. In a rat carotid artery injury model, oral administration (20 mg/kg/day) of I3O for 3 days significantly prolonged occlusion time, and ADP- and collagen-induced platelet aggregation. In washed platelets in vitro, I3O potently inhibited collagen-induced platelet aggregation by suppressing phospholipase Cγ2 (PLCγ2) phosphorylation, subsequently blocking diacylglycerol and arachidonic acid (AA) formation, P-selectin secretion and the production of thromboxane B2. Platelet aggregation induced by phorbol-12-myristate 13-acetate, a protein kinase C (PKC) activator, was inhibited by I3O. Both I3O and U0126, an extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor, markedly reduced collagen-induced phosphorylation of ERK1/2 and p47, resulting in the blockade of cyclooxygenase (COX)-mediated AA metabolite production in AA-treated platelets. I3O suppressed phosphorylation of JNK, p38, GSK-3β, and AKT. I3O inhibited glycoprotein VI (GPVI), as a collagen receptor, by suppressing the phosphorylation of tyrosine kinase Syk of GPVI and the phosphorylation of PLCγ2 and ERK1/2 stimulated by convulxin, as a specific stimulator. Our results indicate that an antiplatelet effect of I3O is due to the suppression of GPVI-mediated signaling pathways. In collagen-stimulated platelets, ERK1/2 phosphorylation is adenylyl cyclase-dependent and leads to the modulation of PKC-p47 signaling and COX-1-mediated AA-metabolic pathways.

Vascular L-type Ca²⁺ channel blocking activity of sulfur-containing indole alkaloids from Glycosmis petelotii

In the search for novel natural compounds endowed with potential antihypertensive activity, a new sulfur-containing indole alkaloid, N-demethylglypetelotine (2), and its known analogue glypetelotine (1), were isolated from the leaves of Glycosmis petelotii. Their structures were established on the basis of spectroscopic evidence. The two alkaloids were assessed for vasorelaxing activity on rat aorta rings and for L-type Ba(2+) current [I(Ba(L))] blocking activity on single myocytes isolated from rat tail artery. Both glypetelotine and N-demethylglypetelotine inhibited phenylephrine-induced contraction with IC50 values of 20 and 50 μM, respectively. The presence of endothelium did not modify their spasmolytic effect. Neither glypetelotine nor N-demethylglypetelotine affected Ca(2+) release from the sarcoplasmic reticulum induced by phenylephrine. The spasmolytic effect of glypetelotine increased with membrane depolarization. In the presence of 60 mM K(+), both compounds inhibited, in a concentration-dependent manner, the contraction induced by cumulative addition of Ca(2+), this inhibition being inversely related to Ca(2+) concentration. Glypetelotine and, less efficiently N-demethylglypetelotine, inhibited I(Ba(L)), the former compound also affecting I(Ba(L)) kinetics. In conclusion, glypetelotine is a novel vasorelaxing agent which antagonizes L-type Ca(2+) channels.

Chemical components of Ardisia splendens leaves and their activity against coxsackie A16 viruses

Using a combination of chromatographic methods, one new flavonol glycoside, myricetin 3,7-di-O-alpha-L-rhamnopyranoside (1), and nine known compounds myricitrin (2), quercetin 3,7-di-O-alpha-L-rhamnopyranoside (3), quercitrin (4), desmanthin-l (5), myricetin 3-O-(3"-O-galloyl)-alpha-L-rhamnopyranoside (6), (+)-catechin (7), benzyl O-1-D-glucopyranoside (8), 2-phenylethyl O-beta-D-glucopyranoside (9), and corilagin (10) were isolated from the leaves of Ardisia splendens Pit. Based on an in vitro test against Coxsackie viruses A16 by SRB assay, only compounds 2, 5, and 10 exhibited activity against Coxsackie viruses A16 with IC50 values of 40.1, 32.2, and 30.5 microM, respectively. This result suggested that compounds 2, 5, and 10 might be potential agents for treating hand, foot and mouth diseases.

Chemical Components of Ardisia splendens Leaves and Their Activity against Coxsackie A16 Viruses

Using a combination of chromatographic methods, one new flavonol glycoside, myricetin 3,7-di-O-α-L-rhamnopyranoside (1), and nine known compounds myricitrin (2), quercetin 3,7-di-O-α-L-rhamnopyranoside (3), quercitrin (4), desmanthin-1 (5), myricetin 3-O -(3″-O-galloyl)-α-L-rhamnopyranoside (6), (+)-catechin (7), benzyl O-β-D-glucopyranoside (8), 2-phenylethyl O-β-D-glucopyranoside (9), and corilagin (10) were isolated from the leaves of Ardisia splendens Pit. Based on an in vitro test against Coxsackie viruses A16 by SRB assay, only compounds 2, 5, and 10 exhibited activity against Coxsackie viruses A16 with IC50 values of 40.1, 32.2, and 30.5 μM, respectively. This result suggested that compounds 2, 5, and 10 might be potential agents for treating hand, foot and mouth diseases.

Bioactive compounds from Vitex leptobotrys

A new lignan, vitexkarinol (1), as well as a known lignan, neopaulownin (2), a known chalcone, 3-(4-hydroxyphenyl)-1-(2,4,6-trimethoxyphenyl)-2-propen-1-one (3), two known dehydroflavones, tsugafolin (4) and alpinetin (5), two known dipeptides, aurantiamide and aurantiamide acetate, a known sesquiterpene, vemopolyanthofuran, and five known carotenoid metabolites, vomifoliol, dihydrovomifoliol, dehydrovomifoliol, loliolide, and isololiolide, were isolated from the leaves and twigs of Vitex leptobotrys through bioassay-guided fractionation. The chalcone (3) was found to inhibit HIV-1 replication by 77% at 15.9 μM, and the two dehydroflavones (4 and 5) showed weak anti-HIV activity with IC50 values of 118 and 130 μM, respectively, while being devoid of cytotoxicity at 150 μM. A chlorophyll-enriched fraction of V. leptobotrys, containing pheophorbide a, was found to inhibit the replication of HIV-1 by 80% at a concentration of 10 μg/mL. Compounds 1 and 3 were further selected to be evaluated against 21 viral targets available at NIAID (National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA).

2-Aryl- and 2-amido-benzothiazoles as multifunctional vasodilators on rat artery preparations

The neuroprotective agent riluzole [2-amino-6-(trifluoromethoxy)benzothiazole] has been shown to antagonize neuronal high-voltage activated Ca(2+) currents. In the search for novel scaffolds leading to potential antihypertensive agents, a series of 2-aryl- and 2-amido-benzothiazoles (HUP) were assessed for their vasorelaxing property on rat aorta rings and for their L-type Ba(2+) currents [I(Ba(L))] blocking activity on single myocytes isolated from the rat tail artery. HUP5 and HUP30, the most potent of the series, inhibited phenylephrine-induced contraction with IC₅₀ values in the range 3-6 µM. The presence of endothelium did not modify their spasmolytic activity. Both HUP5 and HUP30 increased tissue levels of cGMP and shifted to the left the concentration-response curve to sodium nitroprusside. In rings precontracted by phenylephrine, tetraethylammonium or 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) shifted to the right the concentration-relaxation curves of HUP5 and HUP30. The antispasmodic effect of HUP5 and HUP30 was more marked on rings stimulated with 25/30 mM than with 60 mM K(+). HUP5 and HUP30 antagonized both extracellular Ca(2+) influx and Ca(2+) mobilization from intracellular stores in response to phenylephrine: this effect was not modified by the presence of ODQ. I(Ba(L)) was partly inhibited by HUP5 and blocked by HUP30 in a concentration-dependent as well as ODQ-independent manner. In conclusion, HUP5 and HUP30 are vasorelaxing agents that stimulate soluble guanylyl cyclase, activate K(+) channels, and block extracellular Ca(2+) influx. The present benzothiazole derivatives form a novel class of multifunctional vasodilators which may give rise to effective antihypertensive agents.

Oleanane-triterpenoids from Panax stipuleanatus inhibit NF-κB

In continuation of our research to find biological components from Panax stipuleanatus, four oleanane-type triterpenes (12 to 15) were isolated successively. Fifteen oleanane-type saponins (1 to 15) were evaluated for nuclear factor (NF)-κB activity using a luciferase reporter gene assay in HepG2 cells. Compounds 6 to 11 inhibited NF-κB, with IC₅₀ values between 3.1 to 18.9 μM. The effects on inducible nitric oxide synthase and cyclooxygenase-2 by compounds 8, 10, and 11 were also examined using reverse transcription-polymerase chain reaction. Three compounds (8, 10, and 11) inhibited NF-κB activity by reducing the concentration of inflammatory factors in HepG2 cells.