Virulence factors and quorum sensing as targets of new therapeutic options by plant-derived compounds against bacterial infections caused by human and animal pathogens.

The emergence of antibiotic-resistant bacteria and hospital-acquired bacterial infection has become rampant due to antibiotic overuse. Virulence factors are secondary to bacterial growth and are important in their pathogenesis, and therefore, new antimicrobial therapies to inhibit bacterial virulence factors are becoming important strategies against antibiotic resistance. Here, we focus on anti-virulence factors that act through anti-quorum sensing and the subsequent clearance of bacteria by antimicrobial compounds, especially active herbal extracts. These quorum sensing systems are based on toxins, biofilms, and efflux pumps, and bioactive compounds isolated from medicinal plants can treat bacterial virulence pathologies. Ideally, bacterial virulence factors are secondary growth factors of bacteria. Hence, inhibition of bacterial virulence factors could reduce bacterial pathogenesis. Furthermore, anti-virulence factors from herbal compounds can be developed as novel treatments for bacterial infection. Therefore, this narrative review aims to discuss bacterial virulence factors acting through quorum sensing systems that are preserved as targets for treating bacterial infection by plant-derived compounds.

A Thai Traditional Triple-Fruit Formulation "Phikud Tri-Phon" May Provide Fat Loss and Nutritional Benefits.

Obesity and overweight have serious health outcomes. "Phikud Tri-Phon" (PTP) is a traditional Thai medicine comprising three dried fruits from Aegle marmelos L., Morinda citrifolia L., and Coriandrum sativum L. Whether this medicine impacts on metabolic disease is unclear. This study aimed to investigate the phenolic and flavonoid contents of PTP and each of its herbal components, and further assess their antioxidant and anti-adipogenetic activities. Oil-red O staining was measured for lipid accumulation in 3T3-L1 adipocytes. The chemical profiles of PTP and each herbal extract were determined by LC-ESI-QTOF-MS/MS. Our results show that the total phenolic and flavonoid contents of PTP water extract were 22.35-108.42 mg of gallic acid equivalents and PTP ethanolic extract was 1.19-0.93 mg of quercetin equivalents and the DPPH scavenging capacity assay of PTP ethanolic extract (1 mg/mL) was 92.45 ± 6.58 (Trolox equivalent)/g. The PTP extracts and individual herbs had inhibitory adipogenesis activity, which reduced lipid accumulation by approximately 31% in PTP water extract and 22% in PTP ethanolic extract compared with control cells. These results provided insights into the traditional preparation method of using boiling water as a vehicle for PTP. In conclusion, PTP has antioxidant and anti-adipogenesis potential, indicating it is a promising ingredient in functional food and herbal health products.

Bovine omphalocele: errors in embryonic development, veterinarian importance, and the way forward.

Omphalocele is an embryonic developmental error presented as a neonatal visceral umbilical herniation. Epidemiological and embryological studies are reviewed that revise our understanding of midgut development and defects in cattle. Google Scholar and PubMed were searched for omphalocele, exomphalos, calves, calf, cattle, epidemiology, genetics, disease presentation, and omphalocele treatments of bovine neonates. Omphalocele contains small intestine and sometimes liver and/or pyloric abomasum. This condition may arise from inadequately expanded abdominal cavity, herniated midgut entrapment, or inappropriate umbilical ring growth. Full-term neonates are otherwise healthy but comorbidities may be present. Limited epidemiological evidence suggests neonates, commonly female, of dairy dams have much higher omphalocele prevalence than humans but with fewer co-morbidities. Genetic or environmental influences may present at low incidences, especially with co-defects, while also epigenetics operate in metabolically challenged dairy cattle. Calf survival after surgical repair was commonly good if damage to eviscerated tissue was minimal and surgery prompt. Inadequate follow-ups prevented assessment of their commercial value. We also revised understanding of embryonic midgut development. There is little useful epidemiological information on bovine omphaloceles. To address this, we suggest: (i) Observations on omphaloceles should report herd and dam histories, abdominal disposition of contents, and comorbidities. (ii) Cases of surgical restitution must report full histories and thoroughly explore post-surgical follow-ups to assess animal commercial viability. There is a need for very large-scale multi-centre prospective observational studies on cattle health and productivity that should include omphaloceles.

Phenanthrene-enriched extract from Eulophia macrobulbon using subcritical dimethyl ether for phosphodiesterase-5A1 inhibition.

Eulophia macrobulbon (E.C.Parish & Rchb.f.) Hook.f. contains a natural PDE5A1 inhibitor, phenanthrene, 1-(4'-hydroxybenzyl)-4,8- dimethoxyphenanthrene-2,7-diol (HDP), a potential agent for the treatment of erectile dysfunction. The aim of this study was to improve the extraction efficiency of HDP from E. macrobulbon by using a more environmentally friendly extraction method, subcritical liquid dimethyl ether extraction (sDME), instead of classical solvent extraction (CSE) and ultrasound-assisted extraction (UAE). The efficiency and quality of the extracts obtained were evaluated using the following criteria: %process yield; solvent amount; extraction time; temperature; %HDP content by LC-MS, bioactivity as inhibition of phosphodiesterase-5A1 (PDE5A1) by radio-enzymatic assay; and chemical profiles by LC-QTOF-MS. sDME provided the highest content of HDP in the extract at 4.47%, much higher than the use of ethanol (0.4-0.5%), ethyl acetate (1.2-1.7%), or dichloromethane (0.7-1.4%). The process yield for sDME (1.5-2.7%) was similar to or lower than the other solvents (0.9-17%), but as long as the process yield is not prohibitively low, the concentration is a more important measure for clinical use. The optimal conditions for sDME extraction were: Extraction time, 40 min; 200% water as co-solvent; sample-to-solvent ratio of 1:8; temperature, 35 °C. Phenanthrene aglycone and glycoside derivatives were the major constituents of the sDME extracts and lesser amounts of phenolic compounds and sugars. The inhibition of PDE5A1 by sDME (IC50 0.67 ± 0.22 µg/ml) was tenfold more potent than ethanolic extract and other extraction methods, suggesting a high probability of clinical efficacy. Thus, sDME was a more efficient, faster, solvent-saving and environmentally friendly extraction method and more selective for phenanthrene when extracted from E. macrobulbon.

Efficacy of an Anti-Cellulite Herbal Emgel: A Randomized Clinical Trial.

Cellulite describes unsightly skin overlying subcutaneous fat around thighs and buttocks of post-pubescent females. A herbal 'emgel' containing volatile oils and extracts of A traditional Thai herbal compress was tested in a double-blind, placebo-controlled trial with 18 women aged 20-50 year with severe cellulite. Appearance of cellulite (primary outcome), thigh circumferences, skin firmness, and cutaneous blood flow (secondary outcomes) were assessed at baseline, 2, 4, 8 and 12 weeks with a 2-week follow-up. Herbal emgel applied onto the thigh skin twice daily reduced cellulite severity scores in every time point. The score was reduced from 13.4 ± 0.3 (baseline) to 12.1 ± 0.3 (week 2) and 9.9 ± 0.6 (week 12). All secondary outcomes improved with both placebo and herbal emgels suggesting that ingredients in the base-formulation might be responsible. Querying of participants, analysis of their diaries, and physical monthly inspections found no adverse events. The herbal emgel safely improved the appearance of cellulite, while the base emgel may play a role for other endpoints. Further studies on the active constituents and their mechanism of action are needed to further explore these factors.

Efficacy and Safety of Centella Asiatica (L.) Urb. on Wrinkles: A Systematic Review of Published Data and Network Meta-Analysis.

Centella asiatica has many applications in cosmetics, including wrinkle treatments, but its effectiveness remains to be clarified. This systematic review study aimed to demonstrate the efficacy and safety of C. asiatica for reducing facial wrinkles. PubMed, Excerpta Medica dataBASE (EMBASE), Cochrane Central Register of clinical trials, Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Thai Library Integrated System, and Thai university database/journals were searched until May 2019. Five double-blinded randomised controlled trials, including 172 Asian females, were included. Endpoints were wrinkling measured by visual score, image analysis, and participant satisfaction. Two placebo-controlled studies applied gel/creams containing C. asiatica or asiaticoside for 12 w to periorbital skin. Two studies applied tretinoin or Pueraria mirifica contralaterally and by network meta-analysis C. asiatica appeared more effective than P. mirifica but possibly less than tretinoin. Asiaticoside applied as a lipstick for 8 w reduced lip wrinkling. Skin hydration was markedly raised by C. asiatica but not tretinoin. One study reported 10 adverse events for C. asiatica and 35 for tretinoin. Cochrane risk of bias was generally low, reporting was weak, and lack of C. asiatica standardization prevents general application. From the reported data, it is possible to conclude that C. asiatica improved lip and periocular wrinkles, and may replace retinoids if its long-term safety is established and C. asiatica is standardized.

Pharmacokinetics of mitragynine, a major analgesic alkaloid in kratom (Mitragyna speciosa): A systematic review.

BACKGROUND AND OBJECTIVE: Kratom (Mitragyna speciosa) is a tropical tree found in southern Thailand and northern states of the Malay Peninsula. Kratom is commercially available and used as an alternative to treat opioid withdrawal. Mitragynine is the major indole alkaloid found in kratom leaves. This review aimed to summarize available pharmacokinetic information about mitragynine. METHODS: PubMed, Scopus, and Web of Science were systematically searched from their inceptions to June 2018. All types of pharmacokinetic studies of mitragynine were included for further systematic review. RESULTS: Seventeen articles were reviewed. Mitragynine is a lipophilic weak base passively transported across the intestinal wall and blood brain barrier. 85-95% is bound to plasma protein and extensively metabolized by phase I and particularly phase II enzymes. Actions on CYP enzymes are unlikely to impact drug metabolism at concentrations likely to exist in kratom-consuming humans. In rats and humans, mitragynine is rapidly absorbed after orally administration (Tmax˜1.5 h, Cmax˜0.3-1.8 µM). Vd was 37-90 L/kg; t1/2 was 3-9 hr; mostly excreted as metabolites in urine. Bioavailability was estimated as 21%. It also rapidly penetrated and redistributed in brain. A quality assessment tool tailored for pharmacokinetic studies was also created which rated some studies of lower value. CONCLUSION: Rudimentary pharmacokinetics of mitragynine was described in this systematic review. However, the discovered studies provided scant information on the role of metabolism and redistribution into tissues nor the rate of excretion.

Discovery of Natural Steroid 5 Alpha-Reductase Inhibitors.

Human steroid 5 alpha-reductases (S5αRs) and NADPH irreversibly reduce testosterone to the more potent dihydrotestosterone (DHT). S5αR inhibitors are useful treatments for DHT-dependent diseases, including benign prostatic hyperplasia, androgenic alopecia and hair growth, and acne. There are three S5αR isozymes, and there is a need for safer and more isozyme selective inhibitors than finasteride and dutasteride currently licensed. In this study, we review the methods used to screen for S5αR inhibitory activity and describe studies that characterize the ability of herbal preparations and their constituents to inhibit S5αRs. We identified enormous variations between studies in IC50s for finasteride and dutasteride used as standards. Accordingly, we make several recommendations: Stable isozyme specific transfection systems need creating a standardized enzyme/microsome preparation and all three isozymes, as well as androgen receptor binding, should be tested; agreed reaction conditions, especially the substrate concentrations, and separation/quantitation method optimized for high throughput screening; systematic screening of herbal compounds and most extensive use of leads to develop more potent and isozyme specific inhibitors.

Cellulite Reduction by Modified Thai Herbal Compresses; A Randomized Double-Blind Trial.

Cellulite remains an obstinate clinical and cosmetic problem. In this study, we adapted the Thai traditional noninvasive treatment formulated with 5 additional herbals to improve blood flow, edema, and lipolysis, thereby augmenting cellulite treatment. This was a double-blind, randomized placebo-controlled paired trial. Twenty-one women (20-55 years) having cellulite (grade ≥2) were treated with steamed placebo or herbal compresses randomly assigned to one or other thigh twice weekly for 8 weeks with 2 weeks washout. Cellulite reduction was assessed from standardized photographs by 3 blinded evaluators at baseline and every 2 weeks; also assessed were thigh circumferences and cutaneous skin-fold thicknesses, trial diaries, and participant feedback. After 8 weeks, herbal compress treatment reduced Nürnberger-Müller cellulite scores from 12.6 ± 2.0 to 9.9 ± 2.4 compared with 12.5 ± 2.1 to 12.1 ± 2.0 (means ± SEM) for contralateral placebo-treated thighs ( P < .0001; effect size [ES] = 1.16, confidence interval [CI] = 0.48-1.83). Thigh circumferences diminished by 2.2 ± 0.9 cm (herbal) and 1.4 ± 0.7 cm (placebo) (ES = 0.96, CI = 0.30-1.61) and correspondingly skin-folds by 5.6 ± 2.2 and 2.4 ± 1.3 mm (ES = 1.72, CI = 0.99-2.45). No adverse actions were reported, and there were no dropouts, no missing data, and 100% adherence. Herbal compresses were efficacious against cellulite and thigh sizes. The herbal formula might be adapted to other delivery options, and rationally added herbals may increase effectiveness of traditional therapies and more sustainable actions.

Isolation of Retinal Arterioles for Ex Vivo Cell Physiology Studies.

The retina is a highly metabolically active tissue that requires a substantial blood supply. The retinal circulation supports the inner retina, while the choroidal vessels supply the photoreceptors. Alterations in retinal perfusion contribute to numerous sight-threatening disorders, including diabetic retinopathy, glaucoma and retinal branch vein occlusions. Understanding the molecular mechanisms involved in the control of blood flow through the retina and how these are altered during ocular disease could lead to the identification of new targets for the treatment of these conditions. Retinal arterioles are the main resistance vessels of the retina, and consequently, play a key role in regulating retinal hemodynamics through changes in luminal diameter. In recent years, we have developed methods for isolating arterioles from the rat retina which are suitable for a wide range of applications including cell physiology studies. This preparation has already begun to yield new insights into how blood flow is controlled in the retina and has allowed us to identify some of the key changes that occur during ocular disease. In this article, we describe methods for the isolation of rat retinal arterioles and include protocols for their use in patch-clamp electrophysiology, calcium imaging and pressure myography studies. These vessels are also amenable for use in PCR-, western blotting- and immunohistochemistry-based studies.

Hospital admissions associated with medication non-adherence: a systematic review of prospective observational studies.

BACKGROUND: Medication non-adherence in ambulatory care has received substantial attention in the literature, but less so as it affects acute care. Accordingly, we aimed to estimate the frequency with which non-adherence to medication contributes to hospital admissions. METHODS: We searched the Cochrane Library, EMBASE, Cumulative Index to Nursing and Allied Health Literature, International Pharmaceutical Abstracts and PubMed (until December 2017) to identify prospective observational studies that examined prevalence rates of hospital admissions associated with medication non-adherence. A quality assessment was performed using an expanded Crombie checklist. Data extraction covered patterns, circumstances, and patient and other key characteristics of non-adherence. Pooled estimates were obtained using a random-effect model. RESULTS: Of 24 included studies, 8 were undertaken in North America, 7 from Europe, 6 from Asia and 3 from Australia. Most studies (79%) were rated as low risk of bias. All but three studies used combination measures to detect non-adherence, but approaches to assess preventability varied considerably. Across the studies, there was high heterogeneity among prevalence estimates (χ2=548, df 23, p<0.001, I2=95.8%). The median prevalence rate of hospital admissions associated with non-adherence was 4.29% (IQR 3.22%-7.49%), with prevalence rates ranging from 0.72% to 10.79%. By definition, almost all of these admissions were considered preventable. The underlying causes contributing to these admissions included medication cost and side effects, and non-adherence most often involved cardiovascular medicines. CONCLUSIONS: Hospital admissions associated with non-adherence to medication are a common problem. This systematic review highlights important targets for intervention. Greater attention could be focused on adherence to medication during the hospital stay as part of an enhanced medication reconciliation process. Standardisation in study methods and definitions is needed to allow future comparisons among settings; future studies should also encompass emerging economies.

Sesquiterpene-Enriched Extract of Curcuma aeruginosa Roxb. Retards Axillary Hair Growth: A Randomised, Placebo-Controlled, Double-Blind Study.

BACKGROUND: Sesquiterpenes in Curcuma aeruginosa Roxb. inhibit steroid 5α-reductase and dihydrotestosterone production, and reverse androgenic alopecia. This study sought to show that a high sesquiterpene C. aeruginosa extract (CA-ext) retards axillary hair growth in women. METHODS: Thirty women (age 20-52 years) were recruited into a 12-week, double-blind, placebo-controlled intervention for CA-ext treatment, where they were randomly allocated to a left or right armpit group. At weekly intervals, axillary hair length was measured videometrically, the hair was shaved, and lotion was applied (to the contralateral axilla) twice daily via roll-on applicators containing either CA-ext or placebo. The primary endpoint of the study was hair growth. RESULTS: Participants showed 22% (range 8-56%, p < 0.0001) reduced axillary hair growth with CA-ext compared to placebo, albeit delayed by 6 weeks. Participants were satisfied with the treatment and no apparent adverse effects were reported. The quantities of lotion used for each axilla were identical between test and placebo throughout the trial for each participant. Participants reported having shorter and finer armpit hair with the test lotion but disliked its smell, even though it was perfumed. The "free of irritation" description gained the highest questionnaire ratings. CONCLUSION: CA-ext in lotion is an efficacious inhibitor of axillary hair growth, the preparation was well accepted and matched the effectiveness of finasteride. Thus, with some refinement, it should provide an alternative pharmacological treatment for unwanted androgenic hair.

Bacopa monnieri extract increases rat coronary flow and protects against myocardial ischemia/reperfusion injury.

BACKGROUND: This study explored Bacopa monnieri, a medicinal Ayurvedic herb, as a cardioprotectant against ischemia/reperfusion injury using cardiac function and coronary flow as end-points. METHODS: In normal isolated rat hearts, coronary flow, left ventricular developed pressure, heart rate, and functional recovery were measured using the Langendorff preparation. Hearts were perfused with either (i) Krebs-Henseleit (normal) solution, (control), or with 30, 100 µg/ml B. monnieri ethanolic extract (30 min), or (ii) with normal solution or extract for 10 min preceding no-perfusion ischemia (30 min) followed by reperfusion (30 min) with normal solution. Infarct volumes were measured by triphenyltetrazolium staining. L-type Ca2+-currents (ICa, L) were measured by whole-cell patching in HL-1 cells, a mouse atrial cardiomyocyte cell line. Cytotoxicity of B. monnieri was assessed in rat isolated ventricular myocytes by trypan blue exclusion. RESULTS: In normally perfused hearts, B. monnieri increased coronary flow by 63 ± 13% (30 µg/ml) and 216 ± 21% (100 µg/ml), compared to control (5 ± 3%) (n = 8-10, p < 0.001). B. monnieri treatment preceding ischemia/reperfusion improved left ventricular developed pressure by 84 ± 10% (30 µg/ml), 82 ± 10% (100 µg/ml) and 52 ± 6% (control) compared to pre- ischemia/reperfusion. Similarly, functional recovery showed a sustained increase. Moreover, B. monnieri (100 µg/ml) reduced the percentage of infarct size from 51 ± 2% (control) to 25 ± 2% (n = 6-8, p < 0.0001). B. monnieri (100 µg/ml) reduced ICa, L by 63 ± 4% in HL-1 cells. Ventricular myocyte survival decreased at higher concentrations (50-1000 µg/ml) B. monnieri. CONCLUSIONS: B. monnieri improves myocardial function following ischemia/reperfusion injury through recovery of coronary blood flow, contractile force and decrease in infarct size. Thus this may lead to a novel cardioprotectant strategy.

Curcuma aeruginosa Roxb. essential oil slows hair-growth and lightens skin in axillae; a randomised, double blinded trial.

BACKGROUND: Androgenic hair-growth contributes to secondary gender characteristics but can be troublesome in women. Inhibiting axillary hair-growth via 5-α-reductases using the Thai medicinal plant, Curcuma aeruginosa Roxb. is an attractive treatment strategy. HYPOTHESIS/PURPOSE: C. aeruginosa essential oil (CA-oil) formulated as a lotion is an efficacious and safe inhibitor of axillary hair growth. STUDY DESIGN: This trial was a single center, randomized, double-blind, placebo controlled 10 weeks, intervention in 60 women (18-23 years) and 2 weeks washout with axillary hair length was the primary end-point. METHODS: Bioactive-enriched essential oil of C. aeruginosa was formulated with a base lotion. All participants were pre-challenged with lotions by 4-h patch irritation tests to exclude skin reactions. Participants were randomly allocated to use either 1 or 5%w/w CA-oil lotion on one axilla and base-lotion (placebo) to the other for 10 weeks followed by placebo in both axillae for 2 weeks. Every week, the axillae were photographed to measure hair lengths, shaved, and roll-on applicators containing appropriate lotion replaced. Also, skin melanin by spectrophotometry and hair density were measured. RESULTS: From weeks 5-11 of trial, 1 and 5%w/w CA-oil retarded growth by 13 ± 1.5% and 16 ± 0.9% respectively, while placebo was ineffective. CA-oil had no influence on hair density. Both concentrations of CA-oil rapidly and equally effectively brightened skin within 3 weeks which persisted 2 weeks after treatment ceased while placebo darkened the skin. Adherence appeared good as judged by consistency of lotion consumption and between axillae. Participants were satisfied with the treatment and reported reduced hairiness, freedom from any discomforts, but product odour attracted some negative comment. No adverse reactions ascribed to CA-oil were detected or reported. CONCLUSION: This study points to a safe and efficacious dual action on retarding hair-growth and skin lightening by CA-oil.

Efficacy and safety of "Yahom" as a traditional Thai herbal therapy: A systematic review.

ETHNOPHARMACOLOGICAL RELEVANCE: Yahom is a traditional Thai medicine used to treat syncope and abdominal discomfort. AIM OF THE STUDY: This study aimed to systematically review all available evidence which purports to support these claims. MATERIAL AND METHODS: The systematic review accorded with the Cochrane Collaboration framework and PRISMA reporting. Databases including MEDLINE, Excerpta Medica Database (EMBASE), Cochrane library database, and Google Scholar were searched by keywords, Yahom and Ya-hom. Pharmacological and toxicity data from non-animal and animal studies were included. RESULTS: Twenty-four articles: 2 on in vitro cell lines or bacteria, 3 in vitro cell-free, 5 in vitro animal, 13 in vivo and 1 human mainly reported (A) Cardiovascular effects (i) transient hypotension (0.2-0.8g/kg, intravenous injection (i.v.)), increased cerebral blood flow (2g/kg, single oral) and vascular dilatation/relaxation (ii) elevated blood pressure (BP) (0.2-0.8g/kg, i.v. or 2-4g/kg oral) and vasocontraction. Single Yahom doses (3g) given to healthy volunteers had no effect on cutaneous blood flow, ECG or systolic BP although marginally increased diastolic BP was claimed. (B) Yahom (2-4g/kg) completely inhibited gastric acid secretion evoked by gastric secretagogues. (C) Toxicity: Chronic oral doses of selected Yahoms to rodents (0.001-1g/kg) supports its status as generally regarded as safe. CONCLUSIONS: Most studies supported declared objectives relating to perceived Yahom actions, but lacked background demonstrating clinical efficacy, and mechanistic data that would validate conclusions. Our study suggests that research into traditional medicinal herbs needs underpinning by appropriate clinical interventions and pharmacovigilance, thereby optimising efficacy and minimizing toxicity by combining traditional wisdom and modern testing.

Additive Synergism between Asbestos and Smoking in Lung Cancer Risk: A Systematic Review and Meta-Analysis.

Smoking and asbestos exposure are important risks for lung cancer. Several epidemiological studies have linked asbestos exposure and smoking to lung cancer. To reconcile and unify these results, we conducted a systematic review and meta-analysis to provide a quantitative estimate of the increased risk of lung cancer associated with asbestos exposure and cigarette smoking and to classify their interaction. Five electronic databases were searched from inception to May, 2015 for observational studies on lung cancer. All case-control (N = 10) and cohort (N = 7) studies were included in the analysis. We calculated pooled odds ratios (ORs), relative risks (RRs) and 95% confidence intervals (CIs) using a random-effects model for the association of asbestos exposure and smoking with lung cancer. Lung cancer patients who were not exposed to asbestos and non-smoking (A-S-) were compared with; (i) asbestos-exposed and non-smoking (A+S-), (ii) non-exposure to asbestos and smoking (A-S+), and (iii) asbestos-exposed and smoking (A+S+). Our meta-analysis showed a significant difference in risk of developing lung cancer among asbestos exposed and/or smoking workers compared to controls (A-S-), odds ratios for the disease (95% CI) were (i) 1.70 (A+S-, 1.31-2.21), (ii) 5.65; (A-S+, 3.38-9.42), (iii) 8.70 (A+S+, 5.8-13.10). The additive interaction index of synergy was 1.44 (95% CI = 1.26-1.77) and the multiplicative index = 0.91 (95% CI = 0.63-1.30). Corresponding values for cohort studies were 1.11 (95% CI = 1.00-1.28) and 0.51 (95% CI = 0.31-0.85). Our results point to an additive synergism for lung cancer with co-exposure of asbestos and cigarette smoking. Assessments of industrial health risks should take smoking and other airborne health risks when setting occupational asbestos exposure limits.

[6]-Gingerol inhibits de novo fatty acid synthesis and carnitine palmitoyltransferase-1 activity which triggers apoptosis in HepG2.

The de novo fatty acid synthesis catalyzed by key lipogenic enzymes, including fatty acid synthase (FASN) has emerged as one of the novel targets of anti-cancer approaches. The present study explored the possible inhibitory efficacy of [6]-gingerol on de novo fatty acid synthesis associated with mitochondrial-dependent apoptotic induction in HepG2 cells. We observed a dissipation of mitochondrial membrane potential accompanied by a reduction of fatty acid levels. [6]-gingerol administration manifested inhibition of FASN expression, indicating FASN is a major target of [6]-gingerol inducing apoptosis in HepG2 cells. Indeed, we found that increased ROS generation could likely be a mediator of the anti-cancer effect of [6]-gingerol. A reduction of fatty acid levels and induction of apoptosis were restored by inhibition of acetyl-CoA carboxylase (ACC) activity, suggesting an accumulation of malonyl-CoA level could be the major cause of apoptotic induction of [6]-gingerol in HepG2 cells. The present study also showed that depletion of fatty acid following [6]-gingerol treatment caused an inhibitory effect on carnitine palmitoyltransferase-1 activity (CPT-1), whereas C75 augmented CPT-1 activity, indicating that [6]-gingerol exhibits the therapeutic benefit on suppression of fatty acid ß-oxidation.

Curcumin analogues inhibit phosphodiesterase-5 and dilate rat pulmonary arteries.

OBJECTIVES: Phosphodiesterase (PDE)-5 inhibitors are useful as vasodilators for the treatment of pulmonary arterial hypertension. We aimed to study curcumin analogues for PDE5 inhibitory activity and vasorelaxation of rat pulmonary arteries. METHODS: Three natural curcuminoids (1-3) and six synthetic analogues (4-9) were tested for PDE5 and PDE6 inhibitory activities using enzymatic radioassay. Their vasorelaxation was measured using freshly isolated segments of rat pulmonary artery and aorta. KEY FINDINGS: Curcuminoids (1-3) mildly inhibited PDE5 (half maximal inhibitory concentration (IC50 ) = 18 µm): the metamethoxyl of curcumin was important for PDE5 inhibition. But hydroxyl rearrangements, removing both methoxyls and one ketomethylene, yielded the potent 7 and 9 (IC50 = 4 µm) (compared with sildenafil, IC50 = 0.03 µm). Only 1, 3 and 4 were PDE5 selective over PDE6. Triazole-carboxylic addition provided water-solubility while preserving potency. All analogues possessed concentration-dependent vasorelaxant activity on pulmonary arteries (40% of maximal effective concentration (EC40 ) = 29-90 µm, maximum response = 60-90% at 300 µm), while compounds (1-8) were weakly acting in aorta (maximum response <40%). Only demethoxycurcumin (2) and analogues 5, 8, 9 had endothelium-dependent actions. Sildenafil was highly potent (EC40 = 0.04 µm) and highly endothelium dependent in pulmonary artery but weak on intact aorta (EC40 = 1.8 µm). Activity profiles suggest actions through additional cell pathways for promoting vasorelaxation. CONCLUSIONS: Curcumin analogues are potential leads for developing efficacious and selective PDE5 inhibitors and other pathologies of pulmonary hypertension.

Role of ion channels and subcellular Ca2+ signaling in arachidonic acid-induced dilation of pressurized retinal arterioles.

PURPOSE: To investigate the mechanisms responsible for the dilatation of rat retinal arterioles in response to arachidonic acid (AA). METHODS: Changes in the diameter of isolated, pressurized rat retinal arterioles were measured in the presence of AA alone and following pre-incubation with pharmacologic agents inhibiting Ca(2+) sparks and oscillations and K(+) channels. Subcellular Ca(2+) signals were recorded in arteriolar myocytes using Fluo-4-based confocal imaging. The effects of AA on membrane currents of retinal arteriolar myocytes were studied using whole-cell perforated patch clamp recording. RESULTS: Arachidonic acid dilated pressurized retinal arterioles under conditions of myogenic tone. Eicosatetraynoic acid (ETYA) exerted a similar effect, but unlike AA, its effects were rapidly reversible. Arachidonic acid-induced dilation was associated with an inhibition of subcellular Ca(2+) signals. Interventions known to block Ca(2+) sparks and oscillations in retinal arterioles caused dilatation and inhibited AA-induced vasodilator responses. Arachidonic acid accelerated the rate of inactivation of the A-type Kv current and the voltage dependence of inactivation was shifted to more negative membrane potentials. It also enhanced voltage-activated and spontaneous large-conductance calcium-activated K(+) (BK) currents, but only at positive membrane potentials. Pharmacologic inhibition of A-type Kv and BK currents failed to block AA-induced vasodilator responses. Arachidonic acid suppressed L-type Ca(2+) currents. CONCLUSIONS: These results suggest that AA induces retinal arteriolar vasodilation by inhibiting subcellular Ca(2+)-signaling activity in retinal arteriolar myocytes, most likely through a mechanism involving the inhibition of L-type Ca(2+)-channel activity. Arachidonic acid actions on K(+) currents are inconsistent with a model in which K(+) channels contribute to the vasodilator effects of AA.

The role of K+ and Cl- channels in the regulation of retinal arteriolar tone and blood flow.

PURPOSE: This study tested the role of K(+) and Cl(-) channels in the regulation of retinal blood flow. METHODS: Studies were carried out in adult Male Hooded Lister rats. Selectivity of ion-channel blockers was established using electrophysiological recordings from smooth muscle in isolated arterioles under voltage clamp conditions. Leukocyte velocity and retinal arteriolar diameter were measured in anesthetized animals using leukocyte fluorography and fluorescein angiography imaging with a confocal scanning laser ophthalmoscope. These values were used to estimate volumetric flow, which was compared between control conditions and following intravitreal injections of ion channel blockers, either alone or in combination with the potent vasoconstrictor Endothelin 1 (Et1). RESULTS: Voltage-activated K(+) current (IKv) was inhibited by correolide, large conductance (BK) Ca(2+)-activated K(+) current (IKCa) by Penitrem A, and Ca(2+)-activated Cl(-) current (IClCa) by disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS). Intravitreal injections (10 µL) of DIDS (estimated intraocular concentration 10 mM) increased flow by 22%, whereas the BK-blockers Penitrem A (1 µM) and iberiotoxin (4 µM), and the IKv-inhibitor correolide (40 µM) all decreased resting flow by approximately 10%. Endothelin 1 (104 nM) reduced flow by approximately 65%. This effect was completely reversed by DIDS, but was unaffected by Penitrem A, iberiotoxin, or correolide. CONCLUSIONS: These results suggest that Cl(-) channels in retinal arteriolar smooth muscle limit resting blood flow and play an obligatory role in Et1 responses. K(+)-channel activity promotes basal flow but exerts little modifying effect on the Et1 response. Cl(-) channels may be appropriate molecular targets in retinal pathologies characterized by increased Et1 activity and reduced blood flow.