Effects of Leea indica leaf extracts and its phytoconstituents on natural killer cell-mediated cytotoxicity in human ovarian cancer.

BACKGROUND: The rich biodiversity of medicinal plants and their importance as sources of novel therapeutics and lead compounds warrant further research. Despite advances in debulking surgery and chemotherapy, the risks of recurrence of ovarian cancer and resistance to therapy are significant and the clinical outcomes of ovarian cancer remain poor or even incurable. OBJECTIVE: This study aims to investigate the effects of leaf extracts from a medicinal plant Leea indica and its selected phytoconstituents on human ovarian cancer cells and in combination with oxaliplatin and natural killer (NK) cells. METHODS: Fresh, healthy leaves of L. indica were harvested and extracted in 70% methanol by maceration. The crude extract was partitioned with n-hexane, dichloromethane and ethyl acetate. Selected extracts and compounds were analyzed for their effects on cell viability of human ovarian cancer cells, NK cell cytotoxicity, and stress ligands expression for NK cell receptors. They were also evaluated for their effects on TNF-α and IL-1ß production by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated human U937 macrophages. RESULTS: Leaf extracts of L. indica increased the susceptibility of human ovarian tumor cells to NK cell-mediated cytotoxicity. Treatment of cancer cells with methyl gallate but not gallic acid upregulated the expression of stress ligands. Tumor cells pretreated with combination of methyl gallate and low concentration of oxaliplatin displayed increased levels of stress ligands expression and concomitantly enhanced susceptibility to NK cell-mediated cytolysis. Further, NK cells completely abrogated the growth of methyl gallate-pretreated ovarian cancer cells. The leaf extracts suppressed TNF-α and IL-1ß production in human U937 macrophages. Methyl gallate was more potent than gallic acid in down-regulating these cytokine levels. CONCLUSIONS: We demonstrated for the first time that leaf extracts of L. indica and its phytoconstituent methyl gallate enhanced the susceptibility of ovarian tumor cells to NK cell cytolysis. These results suggest that the combined effect of methyl gallate, oxaliplatin and NK cells in ovarian cancer cells warrants further investigation, for example for refractory ovarian cancer. Our work is a step towards better scientific understanding of the traditional anticancer use of L. indica.

Development of Phosphodiesterase-Protein-Kinase Complexes as Novel Targets for Discovery of Inhibitors with Enhanced Specificity.

Phosphodiesterases (PDEs) hydrolyze cyclic nucleotides to modulate multiple signaling events in cells. PDEs are recognized to actively associate with cyclic nucleotide receptors (protein kinases, PKs) in larger macromolecular assemblies referred to as signalosomes. Complexation of PDEs with PKs generates an expanded active site that enhances PDE activity. This facilitates signalosome-associated PDEs to preferentially catalyze active hydrolysis of cyclic nucleotides bound to PKs and aid in signal termination. PDEs are important drug targets, and current strategies for inhibitor discovery are based entirely on targeting conserved PDE catalytic domains. This often results in inhibitors with cross-reactivity amongst closely related PDEs and attendant unwanted side effects. Here, our approach targeted PDE-PK complexes as they would occur in signalosomes, thereby offering greater specificity. Our developed fluorescence polarization assay was adapted to identify inhibitors that block cyclic nucleotide pockets in PDE-PK complexes in one mode and disrupt protein-protein interactions between PDEs and PKs in a second mode. We tested this approach with three different systems-cAMP-specific PDE8-PKAR, cGMP-specific PDE5-PKG, and dual-specificity RegA-RD complexes-and ranked inhibitors according to their inhibition potency. Targeting PDE-PK complexes offers biochemical tools for describing the exquisite specificity of cyclic nucleotide signaling networks in cells.

Facilitators of and barriers to implementing a traditional Chinese medicine collaborative model of care for axial spondyloarthritis: a qualitative study.

BACKGROUND: Conventional therapy may be inadequate for many patients with axial spondyloarthritis (axSpA). Traditional Chinese medicine (TCM) may be a viable alternative, but its effectiveness for axSpA is unknown. We are currently conducting a pragmatic randomised controlled trial (RCT) to investigate the effectiveness of a TCM collaborative model of care (TCMCMC), which combines usual rheumatologic care with acupuncture for patients with axSpA. This nested qualitative sub-study aims to identify facilitators of and barriers to the implementation of the TCMCMC. METHODS: We conducted individual in-depth interviews with participants who had completed the acupuncture regimen to elicit opinions on the facilitators of and barriers to the implementation of the TCMCMC. The interviews were transcribed and analysed using thematic analysis. RESULTS: Twelve participants were included, with data saturation occurring after 10 interviews. The analysis revealed both a number of important 'facilitators' and 'barriers'. Facilitators to the implementation of the TCMCMC included effectiveness of TCM to relieve symptoms, inadequacy of conventional treatment and positive social perceptions of TCM. Barriers included scepticism towards TCM, inability of TCM to provide instant relief, needle-related discomfort, variable effectiveness of TCM influenced by physicians' skills and experience and the high cost of TCM. Recommendations to overcome barriers included further patient education about TCM. CONCLUSION: Policymakers should take into account the various feasibility factors identified in this study when developing and implementing a TCMCMC. TRIAL REGISTRATION NUMBER: NCT03420404 (ClinicalTrials.gov).

Botanical Medicine and Natural Products Used for Erectile Dysfunction.

INTRODUCTION: Erectile dysfunction is the persistent or recurrent inability to achieve or maintain an erection sufficient for intercourse. Despite various treatment options, not all patients respond adequately and their usefulness is limited by adverse effects and cost. Botanical medicine and natural products have been and continue to be invaluable and untapped sources of new drugs, including potentially those to treat erectile dysfunction. OBJECTIVES: To review the current literature on botanical medicine traditionally used as aphrodisiacs and treatment of erectile dysfunction, in particular, scientific and clinical investigations that have been performed, possible active phytoconstituents, and mechanisms of action and to identify gaps in current knowledge to better guide future research efforts. METHODS: A comprehensive literature search was conducted via PubMed, Scopus, Science Direct, and Web of Science on English publications, using various keywords, for example, "herb", "natural product", combined with "erectile dysfunction", "aphrodisiac", and "sexual performance". RESULTS: 369 relevant articles studying medicinal plants used for erectile dysfunction were analyzed. A total of 718 plants from 145 families and 499 genera were reported to be used traditionally as aphrodisiacs and treatment of erectile dysfunction. Top plants used include Pausinystalia johimbe, Lepidium meyenii, and Panax ginseng. Different plant parts are used, with roots being the most common. Less than half of these plants have been evaluated scientifically, using various research methodologies. Clinical trials conducted were collated. Current scientific investigation shows mixed results about their usefulness in enhancing sexual performance. A limited number of studies have attempted to elucidate the mechanisms of action of these medicinal plants. CONCLUSION: A comprehensive literature review on botanical medicine and natural products used for treatment of erectile dysfunction was successfully conducted. Although medicinal plants serve as a potential source of lead compounds for erectile dysfunction drugs, further studies are warranted to further evaluate their efficacy and safety. SinVJ-E, Anand GS, Koh H-L. Botanical Medicine and Natural Products Used for Erectile Dysfunction. Sex Med Rev 2021;9:568-592.

Professionalism in traditional Chinese medicine (TCM) practitioners: a qualitative study.

BACKGROUND: Medical professionalism is important for establishing public trust in doctors. Its definition is culture-sensitive. However, no research has explored medical professionalism in Traditional Chinese Medicine (TCM) practitioners. This study aims to (a) establish the domains of professionalism in TCM practitioners in Singapore, and to (b) compare the domains of professionalism of practitioners trained in TCM and practitioners trained in conventional medicine. METHODS: Data for this qualitative study was collected through in-depth interviews (IDIs) with TCM practitioners. IDIs were audio-recorded and transcribed verbatim. Thematic analysis was conducted by two independent coders using the Professionalism Mini-Evaluation Exercise (P-MEX) as a framework. The domains of professionalism in TCM and conventional medicine were then compared, using data from a similar study on professionalism in practitioners trained in conventional medicine. RESULTS: A total of 27 TCM practitioners (40.7% male) participated in this study. The four domains of professionalism in the P-MEX, namely doctor-patient relationship skills, reflective skills, time management and inter-professional relationship skills, and two new sub-domains, "communicated effectively with patient" and "demonstrated understanding and integrated with conventional medicine", were relevant to TCM practitioners. This is largely similar to that of practitioners trained in conventional medicine, with a few differences, including "ensured continuity of care" and "used health resources appropriately". CONCLUSION: The domains of professionalism in TCM practitioners were established and they are similar to that of practitioners trained in conventional medicine. This study is the first to define medical professionalism in TCM practitioners. Findings will provide guidance on the education of professionalism in TCM practitioners.

Effects of Vitex trifolia L. leaf extracts and phytoconstituents on cytokine production in human U937 macrophages.

BACKGROUND: Dysregulation of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) form the basis of immune-mediated inflammatory diseases. Vitex trifolia L. is a medicinal plant growing in countries such as China, India, Australia and Singapore. Its dried ripe fruits are documented in Traditional Chinese Medicine to treat ailments like rhinitis and dizziness. Its leaves are used traditionally to treat inflammation-related conditions like rheumatic pain. OBJECTIVE: This study aimed to investigate the effects of V. trifolia leaf extracts prepared by different extraction methods (Soxhlet, ultrasonication, and maceration) in various solvents on cytokine production in human U937 macrophages, and identify phytoconstituents from the most active leaf extract. METHODS: Fresh leaves of V. trifolia were extracted using Soxhlet, ultrasonication, and maceration in hexane, dichloromethane, methanol, ethanol or water. Each extract was evaluated for its effects on TNF-α and IL-1ß cytokine production by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated human U937 macrophages. The most active extract was analyzed and further purified by different chemical and spectroscopic techniques. RESULTS: Amongst 14 different leaf extracts investigated, extracts prepared by ultrasonication in dichloromethane and maceration in ethanol were most active in inhibiting TNF-α and IL-1ß production in human U937 macrophages. Further purification led to the isolation of artemetin, casticin, vitexilactone and maslinic acid, and their effects on TNF-α and IL-1ß production were evaluated. We report for the first time that artemetin suppressed TNF-α and IL-1ß production. Gas chromatography-mass spectrometry analyses revealed the presence of eight other compounds. To the best of our knowledge, this is the first report of butylated hydroxytoluene, 2,4-di-tert-butylphenol, campesterol and maslinic acid in V. trifolia leaf extracts. CONCLUSIONS: In conclusion, leaf extracts of V. trifolia obtained using different solvents and extraction methods were successfully investigated for their effects on cytokine production in human U937 macrophages. The findings provide scientific evidence for the traditional use of V. trifolia leaves (a sustainable resource) and highlight the importance of conservation of medicinal plants as resources for drug discovery. Our results together with others suggest further investigation on V. trifolia and constituents to develop novel treatment strategies in immune-mediated inflammatory conditions is warranted.

The direct and indirect costs of axial spondyloarthritis (axSpA) in Singapore.

OBJECTIVE: To estimate the economic annual direct and indirect costs of axial spondyloarthritis (axSpA) in Singapore, and to identify factors associated with these costs. METHODS: A retrospective, cross-sectional, Institutional Review Board-approved study was conducted. A questionnaire was administered to the patients between 2013 and 2016 from the Singapore General Hospital (SGH) spondyloarthritis registry. Direct medical costs and indirect costs were estimated using the SGH database and the human capital approach respectively. Multivariate analyses using generalized linear model with gamma distribution and a log-linked function was conducted to identify factors associated with these total, direct and indirect costs. All costs were adjusted to 2017 using the Singapore Consumer Price Index and converted to 2017 US dollars (USD) by purchasing power parity. RESULTS: A total of 135 consecutive patients were included in the study, with a mean age of 40.4 ± 13.2 years. The overall annual total economic cost to society was around USD 74 790 820, with annual direct cost being the main component of total cost (90.8%). Annual direct cost was around USD 67 931 457, while annual indirect cost was around USD 6 855 951. Presence of extra-spinal symptoms (ever) was associated with an increase in total and direct costs. Higher education level and Patient Global Assessment were associated with an increase in indirect costs. Lack of employment was associated with a decrease in indirect costs. CONCLUSION: The disease burden of axSpA in Singapore is not trivial given that the disease is relatively common. This highlights the need for measures to accommodate patients with axSpA economically in Singapore.

Validity and reliability of the Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in patients with axial spondyloarthritis (axSpA) in Singapore.

INTRODUCTION: The Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) are commonly used instruments for measuring disease activity. However, few studies have assessed their psychometric properties in patients with axial spondyloarthritis (axSpA). We aimed to assess the validity and reliability of ASDAS-CRP and BASDAI in patients with axSpA in Singapore. METHODS: Cross-sectional data from 280 patients with axSpA from a dedicated axSpA clinic in a Singapore tertiary referral hospital from 2011 to 2019 were used. Internal consistency was assessed using Cronbach's alpha. Construct validity was assessed through 12 a priori hypotheses by correlation of overall ASDAS-CRP and BASDAI score with other patient-reported outcomes measures (PROMs). Structural validity was evaluated via confirmatory factor analysis using maximum-likelihood method, where Comparative Fit Index (CFI) >0.95, Tucker-Lewis Index (TLI) >0.95, Root Mean Square Error of Approximation (RMSEA) <0.06 and Standardized Root Mean Residuals (SRMR) <0.08 were indicative of good fit. RESULTS: Among 280 patients (78.2% Male; 92.5% Chinese), ASDAS-CRP showed poor internal consistency of 0.33, while BASDAI showed high internal consistency of 0.87. Convergent and divergent construct validity were demonstrated by fulfillment of 11 out of 12 a priori hypotheses when ASDAS-CRP and BASDAI were compared with other PROMs. Our proposed ASDAS-CRP and BASDAI model showed good fit for a 1-factor structure respectively (CFI = 0.993, TLI = 0.984, RMSEA = 0.036, SRMR = 0.026 for ASDAS-CRP; CFI = 0.993, TLI = 0.985, RMSEA = 0.057, SRMR = 0.022 for BASDAI), demonstrating structural validity. CONCLUSION: This study supports the use of both ASDAS-CRP and BASDAI in measuring disease activity in patients with axSpA in Singapore.

Identification of Phytoconstituents in Leea indica (Burm. F.) Merr. Leaves by High Performance Liquid Chromatography Micro Time-of-Flight Mass Spectrometry.

Leea indica (Vitaceae) is a Southeast Asian medicinal plant. In this study, an ethyl acetate fraction of L. indica leaves was studied for its phytoconstituents using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-microTOF-Q-MS/MS) analysis. A total of 31 compounds of different classes, including benzoic acid derivatives, phenolics, flavonoids, catechins, dihydrochalcones, coumarins, megastigmanes, and oxylipins were identified using LC-MS/MS. Among them, six compounds including gallic acid, methyl gallate, (-)-epigallocatechin-3-O-gallate, myricetin-3-O-rhamnoside, quercetin-3-O-rhamnoside, and 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-ß-d-glucopyranoside were isolated and identified by NMR analysis. The LC-MS/MS analysis led to the tentative identification of three novel dihydrochalcones namely 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-rutinoside, 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-glucosylpentoside and 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-(3″-O-galloyl)-ß-d-glucopyranoside. The structural identification of novel dihydrochalcones was based on the basic skeleton of the isolated dihydrochalcone, 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-ß-d-glucopyranoside and characteristic LC-MS/MS fragmentation patterns. This is the first comprehensive analysis for the identification of compounds from L. indica using LC-MS. A total 24 compounds including three new dihydrochalcones were identified for the first time from the genus Leea.

Traditional Chinese medicine (TCM) collaborative care for patients with axial spondyloarthritis (AcuSpA): protocol for a pragmatic randomized controlled trial.

BACKGROUND: Axial spondyloarthritis (AxSpA) is a chronic disease which results in fatigue, pain, and reduced quality of life (QoL). Traditional Chinese medicine (TCM), especially acupuncture, has shown promise in managing pain. Although a TCM collaborative model of care (TCMCMC) has been studied in cancer, there are no randomized controlled trials investigating TCM in AxSpA. Therefore, we will conduct a pragmatic trial to determine the clinical effectiveness, safety, and cost-effectiveness of TCMCMC for patients with AxSpA. We define TCMCMC as standard TCM history taking and physical examination, acupuncture, and TCM non-pharmacological advice and communications with rheumatologists in addition to usual rheumatologic care. The purpose of this paper is to describe the rationale for and methodology of this trial. METHODS/DESIGN: This pragmatic randomized controlled trial will recruit 160 patients who are diagnosed with AxSpA and have inadequate response to non-steroidal anti-inflammatory drugs (NSAIDs). Simple randomization to usual rheumatologic care or the intervention (TCMCMC) with a 1:1 allocation ratio will be used. Ten 30-min acupuncture sessions will be provided to patients assigned to the TCMCMC arm. All participants will continue to receive usual rheumatologic care. The primary endpoint - spinal pain - will be evaluated at week 6. Secondary endpoints include clinical, quality of life, and economic outcome measures. Patients will be followed up for up to 52 weeks, and adverse events will be documented. DISCUSSION: This trial may provide evidence regarding the clinical effectiveness, safety, and cost-effectiveness of a TCMCMC for patients with AxSpA. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03420404 . Registered on 14 February 2018.

Evaluation of anti-proliferative activity of medicinal plants used in Asian Traditional Medicine to treat cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: The extensive biodiversity of plants in Southeast Asia and inadequate research hitherto warrant a continued investigation into medicinal plants. On the basis of a careful review of fresh medicinal plant usage to treat cancer from previous ethnobotanical interviews in Singapore and from the traditional uses of the indigenous plants, fresh leaves of seven locally grown medicinal plant species were evaluated for anti-proliferative activity. AIM OF THE STUDY: To evaluate the anti-proliferative activity of local medicinal plant species Clausena lansium Skeels, Clinacanthus nutans (Burm. f.) Lindau, Leea indica (Burm. f.) Merr., Pereskia bleo (Kunth) DC., Strobilanthes crispus (L.) Blume, Vernonia amygdalina Delile and Vitex trifolia L. MATERIALS AND METHOD: Fresh, healthy and mature leaves of the seven medicinal plants were harvested from various locations in Singapore and Malaysia for Soxhlet, ultrasonication and maceration extractions in three different solvents (water, ethanol and methanol). Cell proliferation assay using water soluble tetrazolium salt (WST-1) assay was performed on twelve human cancer cell lines derived from breast (MDA-MB-231, T47D), cervical (C33A), colon (HCT116), leukemia (U937), liver (HepG2, SNU-182, SNU-449), ovarian (OVCAR-5, PA-1, SK-OV-3) and uterine (MES-SA/DX5) cancer. RESULTS: A total of 37 fresh leaf extracts from seven medicinal plants were evaluated for their anti-tumour activities in twelve human cancer cell lines. Of these, the extracts of C. lansium, L. indica, P. bleo, S. crispus, V. amygdalina and V. trifolia exhibited promising anti-proliferative activity against multiple cancer cell lines. Further investigation of selected promising leaf extracts indicated that maceration methanolic extract of L. indica was most effective overall against majority of the cancer cell lines, with best IC50 values of 31.5 ±â€¯11.4 µg/mL, 37.5 ±â€¯0.7 µg/mL and 43.0 ±â€¯6.2 µg/mL in cervical C33A, liver SNU-449, and ovarian PA-1 cancer cell lines, respectively. CONCLUSION: The results of this study provide new scientific evidence for the traditional use of local medicinal plant species C. lansium, L . indica, P. bleo, S. crispus, V. amygdalina and V. trifolia in cancer treatment. These results highlight the importance of the upkeep of these indigenous plants in modern society and their relevance as resources for drug discovery.

Ginsenoside Rg1 modulates medial prefrontal cortical firing and suppresses the hippocampo-medial prefrontal cortical long-term potentiation.

BACKGROUND: Panax ginseng is one of the most commonly used medicinal herbs worldwide for a variety of therapeutic properties including neurocognitive effects. Ginsenoside Rg1 is one of the most abundant active chemical constituents of this herb with known neuroprotective, anxiolytic, and cognition improving effects. METHODS: We investigated the effects of Rg1 on the medial prefrontal cortex (mPFC), a key brain region involved in cognition, information processing, working memory, and decision making. In this study, the effects of systemic administration of Rg1 (1 mg/kg, 3 mg/kg, or 10 mg/kg) on (1) spontaneous firing of the medial prefrontal cortical neurons and (2) long-term potentiation (LTP) in the hippocampal-medial prefrontal cortical (HP-mPFC) pathway were investigated in male Sprague-Dawley rats. RESULTS: The spontaneous neuronal activity of approximately 50% the recorded pyramidal cells in the mPFC was suppressed by Rg1. In addition, Rg1 attenuated LTP in the HP-mPFC pathway. These effects were not dose-dependent. CONCLUSION: This report suggests that acute treatment of Rg1 impairs LTP in the HP-mPFC pathway, perhaps by suppressing the firing of a subset of mPFC neurons that may contribute to the neurocognitive effects of Rg1.

Retrospective Study of Reported Adverse Events Due to Complementary Health Products in Singapore From 2010 to 2016.

The objective of this study is to collate and analyse adverse event reports associated with the use of complementary health products (CHP) submitted to the Health Sciences Authority (HSA) of Singapore for the period 2010-2016 to identify various trends and signals for pharmacovigilance purposes. A total of 147,215 adverse event reports suspected to be associated with pharmaceutical products and CHP were received by HSA between 2010 and 2016. Of these, 143,191 (97.3%) were associated with chemical drugs, 1,807 (1.2%) with vaccines, 1,324 (0.9%) with biological drugs (biologics), and 893 (0.6%) with CHP. The number of adverse event reports associated with Chinese Proprietary Medicine, other complementary medicine and health supplements are presented. Eight hundred and ninety three adverse event reports associated with CHP in the 7-year period have been successfully collated and analyzed. In agreement with other studies, adverse events related to the "skin and appendages disorders" were the most commonly reported. Most of the cases involved dermal allergies (e.g., rashes) associated with the use of glucosamine products and most of the adulterated products were associated with the illegal addition of undeclared drugs for pain relief. Dexamethasone, chlorpheniramine, and piroxicam were the most common adulterants detected. Reporting suspected adverse events is strongly encouraged even if the causality is not confirmed because any signs of clustering will allow rapid regulatory actions to be taken. The findings from this study help to create greater awareness on the health risks, albeit low, when consuming CHP and dispelling the common misconception that "natural" means "safe." In particular, healthcare professionals and the general public should be aware of potential adulteration of CHP. The analysis of spontaneously reported adverse events is an important surveillance system in monitoring the safety of CHP and helps in the understanding of the risk associated with the use of such products. Greater collaboration and communication between healthcare professionals, regulators, patients, manufacturers, researchers, and the general public are important to ensure the quality and safety of CHP.

A randomized, double-blind, placebo- controlled study on the anti-haemostatic effects of Curcuma longa, Angelica sinensis and Panax ginseng.

PURPOSE: Herbs with "blood-activating" properties by traditional medicine theory often raise concerns for their possible anti-platelet or anticoagulation effects based on reports from in vitro studies. Such herbs have been implicated for bleeding manifestations based on only anecdotal reports. In particular, the combination of such herbs with anti-platelet agents is often empirically advised against despite lack of good clinical evidence. Here we studied 3 commonly used herbal preparations Curcuma longa, Angelica sinensis and Panax ginseng on their respective anti-platelet and anticoagulation effect, alone and in combination with aspirin. STUDY DESIGN: This is a randomized, double-blind, placebo-controlled trial involving 25 healthy volunteers for each herbal preparation. METHODS: Each subject underwent 3 phases comprising of herbal product alone, aspirin alone and aspirin with herbal product, where each phase lasted for 3 weeks with 2 weeks of washout between phases. PT/APTT, platelet function by light transmission aggregometry and thrombin generation assay by calibrated automated thrombogram were measured at baseline and after each phase. Information on adverse reaction including bleeding manifestations was collected after each phase. RESULTS: On the whole there was no clinically relevant impact on platelet and coagulation function. With the exception of 5 of 24 subjects in the Curcuma longa group, 2 of 24 subjects in the Angelica sinensis group and 1 of 23 subjects in the Panax ginseng group who had an inhibition in arachidonic-acid induced platelet aggregation, there was no effect of these 3 herbals products on platelet aggregation by other agonists. Combination of these herbal products with aspirin respectively did not further aggravate platelet inhibition caused by aspirin. None of the herbs impaired PT/APTT or thrombin generation. There was no significant bleeding manifestation. CONCLUSIONS: This study on healthy volunteers provides good evidence on the lack of bleeding risks of Curcuma longa, Angelica sinensis and Panax ginseng either used alone or in combination with aspirin.

Isolation and characterization of a tadalafil analogue, N-cyclopentyl nortadalafil in health supplement.

A tadalafil analogue was detected for the first time during the screening of a health supplement for undeclared sexual enhancement drugs. The compound had been isolated and purified by preparative high-pressure liquid chromatography (HPLC). Its chemical structure was elucidated using high-resolution mass spectrometry (HRMS), electrospray ionization tandem mass spectrometry (ESI-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy. The compound had a protonated molecular ion at m/z 444 with a chemical formula of C26H25N3O4. The data obtained from the MS analysis of the compound suggested that the N-methyl group on the piperazinedione moiety of tadalafil was substituted with a -C5H9 group. Analysis using NMR was performed and the -C5H9 group was characterized as a cyclopentyl moiety. The analogue was named N-cyclopentyl nortadalafil.

Protective effects of ginseng on neurological disorders.

Ginseng (Order: Apiales, Family: Araliaceae, Genus: Panax) has been used as a traditional herbal medicine for over 2000 years, and is recorded to have antianxiety, antidepressant and cognition enhancing properties. The protective effects of ginseng on neurological disorders are discussed in this review. Ginseng species and ginsenosides, and their intestinal metabolism and bioavailability are briefly introduced. This is followed by molecular mechanisms of effects of ginseng on the brain, including glutamatergic transmission, monoamine transmission, estrogen signaling, nitric oxide (NO) production, the Keap1/Nrf2 adaptive cellular stress pathway, neuronal survival, apoptosis, neural stem cells and neuroregeneration, microglia, astrocytes, oligodendrocytes and cerebral microvessels. The molecular mechanisms of the neuroprotective effects of ginseng in Alzheimer's disease (AD) including ß-amyloid (Aß) formation, tau hyperphosphorylation and oxidative stress, major depression, stroke, Parkinson's disease and multiple sclerosis are presented. It is hoped that this discussion will stimulate more studies on the use of ginseng in neurological disorders.

Oxaliplatin regulates expression of stress ligands in ovarian cancer cells and modulates their susceptibility to natural killer cell-mediated cytotoxicity.

Selected cytotoxic chemicals can provoke the immune system to recognize and destroy malignant tumors. Most of the studies on immunogenic cell death are focused on the signals that operate on a series of receptors expressed by dendritic cells to induce tumor antigen-specific T-cell responses. Here, we explored the effects of oxaliplatin, an immunogenic cell death inducer, on the induction of stress ligands and promotion of natural killer (NK) cell-mediated cytotoxicity in human ovarian cancer cells. The results indicated that treatment of tumor cells with oxaliplatin induced the production of type I interferons and chemokines and enhanced the expression of major histocompatibility complex class I-related chains (MIC) A/B, UL16-binding protein (ULBP)-3, CD155 and TNF-related apoptosis-inducing ligand (TRAIL)-R1/R2. Furthermore, oxaliplatin but not cisplatin treatment enhanced susceptibility of ovarian cancer cells to NK cell-mediated cytolysis. In addition, activated NK cells completely abrogated the growth of cancer cells that were pretreated with oxaliplatin. However, cancer cells pretreated with the same concentration of oxaliplatin alone were capable of potentiating regrowth over a period of time. These results suggest an advantage in combining oxaliplatin and NK cell-based therapy in the treatment of ovarian cancer. Further investigation on such potential combination therapy is warranted.

Hepatotoxic potential of asarones: in vitro evaluation of hepatotoxicity and quantitative determination in herbal products.

α and ß asarones are natural constituents of some aromatic plants, especially species of the genus Acorus (Araceae). In addition to reports of beneficial properties of asarones, genotoxicity and carcinogenicity are also reported. Due to potential toxic effects of ß-asarone, a limit of exposure from herbal products of ~2 µg/kg body weight/day has been set temporarily until a full benefit/risk assessment has been carried out by the European Medicines Agency. Therefore, it is important to monitor levels of ß-asarone in herbal products. In this study, we developed a simple, rapid and validated GC-MS method for quantitative determination of asarones and applied it in 20 pediatric herbal products after detecting high concentrations of ß-asarone in a product suspected to be implicated in hepatotoxicity in a 3 month old infant. Furthermore, targeted toxicological effects were further investigated in human hepatocytes (THLE-2 cells) by employing various in vitro assays, with the goal of elucidating possible mechanisms for the observed toxicity. Results showed that some of the products contained as much as 4-25 times greater amounts of ß-asarone than the recommended levels. In 4 of 10 samples found to contain asarones, the presence of asarones could not be linked to the labeled ingredients, possibly due to poor quality control. Cell-based investigations in THLE-2 cells confirmed the cytotoxicity of ß-asarone (IC50 = 40.0 ± 2.0 µg/mL) which was associated with significant lipid peroxidation and glutathione depletion. This observed cytotoxic effect is likely due to induction of oxidative stress by asarones. Overall, the results of this study ascertained the usability of this GC-MS method for the quantitative determination of asarones from herbal products, and shed light on the importance of controlling the concentration of potentially toxic asarones in herbal products to safeguard consumer safety, especially when the target consumers are young children. Further investigations of the toxicity of asarones are warranted.

A Review of Botanical Characteristics, Traditional Usage, Chemical Components, Pharmacological Activities, and Safety of Pereskia bleo (Kunth) DC.

Pereskia bleo, a leafy cactus, is a medicinal plant native to West and South America and distributed in tropical and subtropical areas. It is traditionally used as a dietary vegetable, barrier hedge, water purifier, and insect repellant and for maintaining health, detoxification, prevention of cancer, and/or treatment of cancer, hypertension, diabetes, stomach ache, muscle pain, and inflammatory diseases such as dermatitis and rheumatism. The aim of this paper was to provide an up-to-date and comprehensive review of the botanical characteristics, traditional usage, phytochemistry, pharmacological activities, and safety of P. bleo. A literature search using MEDLINE (via PubMed), Science direct, Scopus and Google scholar and China Academic Journals Full-Text Database (CNKI) and available eBooks and books in the National University of Singapore libraries in English and Chinese was conducted. The following keywords were used: Pereskia bleo, Pereskia panamensis, Pereskia corrugata, Rhodocacus corrugatus, Rhodocacus bleo, Cactus panamensis, Cactus bleo, Spinach cactus, wax rose, Perescia, and Chinese rose. This review revealed the association between the traditional usage of P. bleo and reported pharmacological properties in the literature. Further investigation on the pharmacological properties and phytoconstituents of P. bleo is warranted to further exploit its potentials as a source of novel therapeutic agents or lead compounds.

Ethnobotanical survey of usage of fresh medicinal plants in Singapore.

ETHNOPHARMACOLOGICAL RELEVANCE: The use of medicinal plants in human health has been documented since ancient times and they provide a useful source of new therapeutics. In Singapore, despite the accessibility to modern healthcare, there still exist pockets of the population who choose to use locally grown fresh medicinal plants for health promotion and even therapeutic purposes. However to date, there is no published report of first-hand account of their usage in Singapore. As land is scarce and rapidly used for re-development, such important knowledge may be lost if not properly documented in time. This work safeguards the local folk knowledge, and provides information on common and scarcely reported fresh medicinal plants. The objective of this study is to gather information regarding the usage of fresh medicinal plants in Singapore through face-to-face interviews. MATERIALS AND METHODS: Information on demographic data and plant-use methods were collated via face-to-face interviews of 200 fresh medicinal plant users who have used fresh medicinal plants in the last five years. The survey protocol was approved by the National University of Singapore Institutional Review Board and informed consent was obtained from every participant. RESULTS: A total of 414 plants represented by 104 plant species from 44 families were reportedly used by the 200 participants. The five most commonly used plants were Clinacanthus nutans (34 users), Strobilanthes crispus (31 users), Pereskia bleo (25 users), Aloe vera (18 users) and Zingiber officinale (16 users). Leaves were the most commonly used plant part while preparing a decoction was the most common method of preparation. The majority of interviewees used plants for general health purposes and to treat diseases related to the respiratory system and cancer. CONCLUSIONS: Our survey has successfully documented the rich wealth of traditional usage and knowledge on 414 fresh medicinal plants grown in Singapore through face-to-face interviews with 200 users. This study will serve as a useful resource for identifying promising plants for future drug discovery efforts. Scientific evaluations of these medicinal plants are warranted and should be carried out.