Induction of apoptosis and autophagy by dichloromethane extract from Patrinia scabiosaefolia Fisch on acute myeloid leukemia cells

Patrinia scabiosaefolia Fisch (PS), a perennial herb belonging to the genus Pinus in the family Pinnacle Sauce, has been previously known for its analgesic, anti-inflammatory, antibacterial, and antitumor properties. However, the specific mechanism behind its antileukemic effect remains unknown. This study focused on the cytotoxicity and potential modes of action of the dichloromethane extract from PS (DEPS) in acute myeloid leukemia (AML) cells. Our results demonstrated that DEPS reduced cell viability, arrested the cell cycle in the G2/M phase, disrupted the mitochondrial membrane potential, increased reactive oxygen species (ROS) production, and upregulated the expression of Bax/Bcl-2 and Cleaved caspase-3. However, the impact of DEPS on cell viability and the expression of apoptosis-associated proteins was reversed upon pretreatment with the caspase-3 inhibitor (Z-DEVD-FMK) in HL-60 cells, which demonstrated that DEPS could induce apoptosis through the mitochondria-associated apoptotic pathway. Interestingly, DEPS also influenced autophagy by upregulating the expression of LC3II/I, P62, and Beclin-1 proteins, and the autophagy inhibition chloroquine(CQ) could attenuate the apoptotic effects of DEPS in HL-60 cells. Furthermore, SMART 2.0 analysis predicted that the main components present in DEPS were likely terpenoids. In conclusion, DEPS possibly exerts antileukemic effects by downregulating the PI3K/AKT and ERK pathways, thereby promoting intracellular ROS production, activating the mitochondrial apoptotic pathway, and affecting autophagy, providing valuable insights for the potential future application of PS in the treatment of AML.

Acacia mangium: A promising plant for isolating anti-hepatitis C virus agents

Background: Medicinal plants are potential resources for isolating drug candidates. Various plants have been reported to possess pharmacological effects including anti-hepatitis C activities. The current study examined the anti-hepatitis C virus (HCV) activities of Acacia mangium extracts in solvents with various polarities and further evaluated the mechanism of action of the extracts using Western blotting and combination treatment models. Methods: The leaves of A. mangium were extracted in two phases, first in ethanol and then in solvents with different polarities (n-hexane, dichloromethane, and methanol). HCV-infected Huh7it-1 cells were treated with the extracts at concentrations of 0.01, 0.1, 1, 10, 50, and 100 µg/mL. Results: The results revealed the strong anti-HCV activities of the extracts. The 50% inhibition concentrations (IC 50s) of the ethanol, n-hexane, dichloromethane and methanol extracts were of 4.6 ± 0.3, 2.9 ± 0.2, 0.2 ± 0.3, and 2.8 ± 0.2 μg/mL, respectively, and no cytotoxic effect was detected. These extracts displayed stronger effects than the positive control ribavirin. The mode of action of the ethanol extract was evaluated at 30 µg/mL, revealing that the inhibitory effect was stronger on the post-entry step than on the entry step. Western blotting revealed that the extracts decreased NS3 protein expression, indicating that virus replication was suppressed. Further evaluation illustrated that combined treatment with the ethanol extract enhanced the anti-viral activity of simeprevir. Conclusions: These results indicated that A. mangium leaves could represent sources of anti-HCV agents.

Anti-Streptococcus mutans, anti-adherence and anti-acidogenic activity of Uvaria chamae P. Beauv

ETHNOPHARMACOLOGICAL RELEVANCE

Streptococcus mutans a key pathogen, produces biofilm, acids and extracellular polysaccharides in the oral cavity; which leads to the development of dental caries. Control of these pathogenic markers can prevent dental caries. Uvaria chamae P. Beauv. is a medicinal plant traditionally used for many ailments including oral infections. Root, leaves and bark extracts has proven antibacterial activity including activity against caries causing S. mutans. However, its effect on the virulence properties of S. mutans, responsible for the development of dental caries, has not been studied.

AIM OF THE STUDY

This study investigated the phytochemical constituents, anti-S. mutans, anti-adherence and anti-acidogenic activity of U. chamae root extract.

MATERIALS AND METHODS

Extracts were prepared and phytochemical analysis was performed. Minimum inhibitory concentrations (MIC) were determined, and MIC and sub-MIC concentrations of the best solvent were selected for their effect on the virulence factors of S. mutans. The results were analysed using one-way ANOVA and Wilcoxon Rank Sum Tests.

RESULTS

The dichloromethane extract, with proanthocyanidin as a major chemical constituent, produced an MIC of 0.02 mg/ml. At 6 h, exposure to 0.005, 0.01, and 0.02 mg/ml extract significantly reduced S. mutans adherence by 39, 59, and 77% respectively (p < 0.05). Uvaria chamae also significantly inhibited acid production in S. mutans at 10, 12, 14 and 16 h (p < 0.05). At ½ MIC, the plant extract caused remarkable downregulation of the virulence genes responsible for the adherence, biofilm formation, extracellular polysaccharide synthesis and acid production.

CONCLUSIONS

This suggests that U. chamae extract may potentially be used to inhibit the proliferation of S. mutans and silencing the expression of pathology-related genes, which will prevent the development of dental caries.

Corneal Healing and Recovery of Ocular Crystallinity with a Dichloromethane Extract of Sedum dendroideum D.C. in a Novel Murine Model of Ocular Pterygium

Pterygium is a corneal alteration that can cause visual impairment, which has been traditionally treated with the sap of Sedum dendroideum D.C. The pharmacological effect of a dichloromethane extract of S. dendroideum was demonstrated and implemented in a pterygium model on the healing process of corneal damage caused by phorbol esters. In mice of the ICR strain, a corneal lesion was caused by intravitreal injection of tetradecanoylphorbol acetate (TPA). The evolution of the corneal scarring process was monitored with vehicle, dexamethasone, and dichloromethane extract of S. dendroideum treatments by daily ophthalmic administration for fifteen days. The lesions were evaluated in situ with highlighted images of fluorescence of the lesions. Following treatment levels in eyeballs of IL-1α, TNF-α, and IL-10 cytokines were measured. The effective dose of TPA to produce a pterygium-like lesion was determined. The follow-up of the evolution of the scarring process allowed us to define that the treatment with S. dendroideum improved the experimental pterygium and had an immunomodulatory effect by decreasing TNF-α, IL-1α, and maintaining the level of IL-10 expression, without difference with respect to the healthy control. Traditional medical use of S. dendroideum sap to treat pterygium is fully justified by its compound composition.

Aquilariae Lignum Methylene Chloride Fraction Attenuates IL-1β-Driven Neuroinflammation in BV2 Microglial Cells

Microglial hyperactivation and neuroinflammation are known to induce neuronal death, which is one of the main causes of neurodegenerative disorders. We previously found that Aquilariae Lignum extract attenuated both neuronal excitotoxicity and neuroinflammation in vivo and in vitro. For further analysis, we extracted the methylene chloride fraction of Aquilariae Lignum to determine the bioactive compounds. In this study, we investigated the anti-neuroinflammatory effects and underlying mechanisms of the Aquilariae Lignum fraction (ALF) using lipopolysaccharide (LPS)-stimulated BV2 microglial cells. BV2 cells were pretreated with ALF (0.5, 1, and 2.5 μg/mL) before treatment with LPS (1 μg/mL). Pretreatment with ALF significantly attenuated the LPS-induced overproductions of nitric oxide (NO), cyclooxygenase-2 (COX-2), prostaglandin E₂ (PGE₂), and interleukin (IL)-1β. These anti-inflammatory effects were supported by ALF-mediated modulation of the nuclear factor-kappa B (NF-κB) pathway. Furthermore, ALF exerted strong anti-inflammasome effects, as shown by IL-1β-specific inhibitory activity, but not activity against tumor necrosis factor (TNF)-α, along with inhibition of caspase-1 activity and NACHT, LRR, and PYD domain-containing protein 3 (NLRP3)-related molecules. These results indicate the potent anti-neuroinflammatory activity of ALF and that its underlying mechanism may involve the regulation of NLRP3 inflammasome-derived neuroinflammation in microglial cells.

Screening of the Dichloromethane: Methanolic Extract of Centella asiatica for Antibacterial Activities against Salmonella typhi, Escherichia coli, Shigella sonnei, Bacillus subtilis, and Staphylococcus aureus

Bacterial infections are responsible for a large number of deaths every year worldwide. On average, 80% of the African population cannot afford conventional drugs. Moreover, many synthetic antibiotics are associated with side effects and progressive increase in antimicrobial resistance. Currently, there is growing interest in discovering new antibacterial agents from ethnomedicinal plants. About 60% of the population living in developing countries depends on herbal drugs for healthcare needs. This study involved the screening of Centella asiatica commonly used by herbal medicine practitioners in Kisii County to treat symptoms related to bacterial infections. Standard bioassay methods were applied throughout the study. They included preliminary screening of dichloromethane: methanolic extract of Centella asiatica against human pathogenic bacteria including Salmonella typhi ATCC 19430, Escherichia coli ATCC 25922, Shigella sonnei ATCC 25931, Bacillus subtilis ATCC 21332, and Staphylococcus aureus ATCC 25923 using agar disc diffusion, broth microdilution method, and time-kill kinetics with tetracycline as a positive control. Phytochemical screening was carried out to determine the different classes of compounds in the crude extracts. Data were analyzed using one way ANOVA and means separated by Tukey's test. Dichloromethane: methanolic extract of Centella asiatica was screened against the selected bacterial strains. Time-kill kinetic studies of the extracts showed dose- and time-dependent kinetics of antibacterial properties. Phytochemical screening of the DCM-MeOH extract revealed the presence of alkaloids, flavonoids, phenolics, terpenoids, cardiac glycosides, saponins, steroids, and tannins. The present study indicates that the tested plant can be an important source of antibacterial agents and recommends that the active phytoconstituents be isolated, identified, and screened individually for activities and also subjected further for in vivo and toxicological studies.

Head Louse Feces: Chemical Analysis and Behavioral Activity

Human head lice Pediculus humanus capitis (De Geer) (Phthiraptera: Pediculidae) are insect parasites closely associated with humans, feeding on the blood of their hosts and causing them skin irritation and probable secondary infections. Despite being a severe nuisance, very few studies have reported on intraspecific chemical communication in head lice. Here, we evaluated the attractive response of head lice to the volatile compounds and solvent extracts from their feces. We also chemically analyzed the main volatile components of these feces and those of the feces' extracts. Head lice were attracted to the methanol extract of their feces but not to the hexane or dichloromethane extracts, suggesting the polar nature of bioactive chemicals present in head louse feces. Follow-up chemical identifications, in fact, showed the presence of hypoxanthine, uric acid, and another purine tentatively identified as either guanine or iso-guanine. Additionally, head lice were significantly attracted by volatiles emitted from samples containing feces. The volatiles emanated from feces alone contained 19 identified substances: 2-pentanone, hexanal, heptanal, 3-methyl-3-buten-1-ol, octanal, sulcatone, nonanal, acetic acid, 2-ethyl-1-hexanol, decanal, 1-octanol, butyric acid, 1-nonanol, hexanoic acid, octanoic acid, 2,6-dimethyl-7-octen-2-ol, 2-undecanone, geranylacetone, and hexadecane. The major compounds found were decanal, nonanal, hexanal, and acetic acid, together representing approximately 60% of the identified compounds. This work represents the first chemical evidence of intraspecies communication among head lice. The results support the existence of active substances present in the feces of P. humanus capitis that may be involved in its aggregation behavior.

β-Peltoboykinolic Acid from Astilbe rubra Attenuates TGF-β1-Induced Epithelial-to-Mesenchymal Transitions in Lung Alveolar Epithelial Cells

Epithelial-to-mesenchymal transition (EMT) is increasingly recognized as contributing to the pathogenesis of idiopathic pulmonary fibrosis. Therefore, novel plant-based natural, active compounds have been sought for the treatment of fibrotic EMT. The aim of the present study was to investigate the inhibitory effects of Astilbe rubra on TGF-β1-induced EMT in lung alveolar epithelial cells (A549). A. rubra was subjected to extraction using 70% ethanol (ARE), and ethanol extracts of the aerial part and that of the rhizome were further partitioned using various solvents. Protein expression and cell motility were investigated to evaluate the inhibitory effects of ARE on EMT. EMT occurred in A549 cells treated with TGF-β1, but was prevented by co-treatment with ARE. The dichloromethane fractions showed the strongest inhibitory effect on TGF-β1-induced EMT. β-Peltoboykinolic acid was isolated from the dichloromethane fractions of A. rubra by activity-oriented isolation. β-Peltoboykinolic acid not only attenuated TGF-β1-induced EMT, but also the overproduction of extracellular matrix components including type I collagen and fibronectin. The Smad pathway activated by TGF-β1 was inhibited by co-treatment with β-peltoboykinolic acid. Taken together, these results indicate that β-peltoboykinolic acid from A. rubra and dichloromethane fractions shows potential as an antifibrotic agent in A549 cells treated with TGF-β1.

The α-amylase and α-glucosidase inhibitory activities of the dichloromethane extracts and constituents of Ferulago bracteata roots

CONTEXT

Ferulago (Apiaceae) species have been used since ancient times for the treatment of intestinal worms, hemorrhoids, and as a tonic, digestive, aphrodisiac, or sedative, as well as in salads or as a spice due to their special odors.

OBJECTIVES

This study reports the α-amylase and α-glucosidase inhibitory activities of dichloromethane extract and bioactive compounds isolated from Ferulago bracteata Boiss. & Hausskn. roots.

MATERIALS AND METHODS

The isolated compounds obtained from dichloromethane extract of Ferulago bracteata roots through bioassay-guided fractionation and isolation process were evaluated for their in vitro α-amylase and α-glucosidase inhibitory activities at 5000-400 µg/mL concentrations. Compound structures were elucidated by detailed analyses (NMR and MS).

RESULTS

A new coumarin, peucedanol-2'-benzoate (1), along with nine known ones, osthole (2), imperatorin (3), bergapten (4), prantschimgin (5), grandivitinol (6), suberosin (7), xanthotoxin (8), felamidin (9), umbelliferone (10), and a sterol mixture consisted of stigmasterol (11), β-sitosterol (12) was isolated from the roots of F. bracteata. Felamidin and suberosin showed significant α-glucosidase inhibitory activity (IC₅₀ 0.42 and 0.89 mg/mL, respectively) when compared to the reference standard acarbose (IC₅₀ 4.95 mg/mL). However, none of the tested extracts were found to be active on α-amylase inhibition.

DISCUSSION AND CONCLUSIONS

The present study demonstrated that among the compounds isolated from CH₂Cl₂ fraction of F. bracteata roots, coumarins were determined as the main chemical constituents of this fraction. This is the first report on isolation and characterization of the bioactive compounds from root extracts of F. bracteata and on their α-amylase and α-glucosidase inhibitory activities.

Influence of fumigants on sunflower seeds: Characteristics of fumigant desorption and changes in volatile profiles

Fumigation of transport containers is common practice to protect stored products from pests. Yet little is known about the desorption times and effects of the highly toxic gases used in this process. To shed light on the behavior of fumigants in real food, we treated sunflower seeds (Helianthus annuus L.) with 100ppm phosphine (PH₃), methyl bromide (MeBr) or 1,2-dichloroethane (DCE) for 72h. The compound concentrations in the air were then analyzed by thermal desorption/2D gas chromatography coupled to mass spectrometry and flame photometric detection (TD-2D-GC-MS/FPD). A desorption time of several months was observed for DCE, whereas PH₃ and MeBr were outgassed in a matter of days. To investigate possible interactions between gases and constituents of the seeds, non-fumigated, fumigated and outgassed samples were analyzed by headspace solid-phase microextraction GC-MS. We observed significantly different volatile profiles in fumigated and subsequently outgassed seeds compared to non-fumigated seeds. Whereas PH₃-treated seeds released far more terpenoids, the volatile pattern of seeds exposed to DCE revealed significantly fewer terpenoids but more aldehydes. These changes are likely to affect food aroma characteristics.

Effects of dichloromethane and butanol fractions of Gochnatia polymorpha floccosa in maternal reproductive outcome, embryo-fetal development and DNA integrity in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Gochnatia polymorpha ssp. floccosa (Asteraceae) also known as ''Cambará'' is used as medicinal plant in Brazil to treat infections and inflammation. Previous studies showed that its ethanolic extract could be bioprospecting of a new anti-inflammatory phytotherapy for use during pregnancy. This work aimed to evaluate dichloromethane (DCM) and butanolic (BT) fractions from G. polymorpha on embryo-fetal development and DNA integrity in mice.

MATERIALS AND METHODS

Female mice were treated with 50 and 20mg/kg of the DCM and BT fractions, respectively, during organogenesis and gestational period.

RESULTS AND CONCLUSION

The present study shows that DCM and BT fractions from G. polymorpha possess mutagenic activity but are not teratogenic. Based on the fact that the reproductive indices are similar in control and treated animals, we may infer that the mutagenic effect was in somatic cell, at least in part, because the reabsorption number and reabsorption rates did not change in DCM and BT exposed groups.

Vasorelaxant mode of action of dichloromethane-soluble extract from Agastache mexicana and its main bioactive compounds

CONTEXT

Agastache mexicana (Kunth) Lint & Epling (Lamiaceae) is a plant used in Mexican traditional medicine for the treatment of hypertension, anxiety and so on.

OBJECTIVE

To determine the vasorelaxant effect and functional mode of action of dichloromethane-soluble extract from A. mexicana (DEAm) and isolate the constituents responsible for the pharmacological activity.

MATERIALS AND METHODS

Extracts were prepared from the aerial parts of A. mexicana (225.6 g) by successive maceration with hexane, dichloromethane and methanol (three times for 72 h at room temperature), respectively. DEAm (0.01-1000 μg/mL), fractions (at 174.27 μg/mL), acacetin and ursolic acid (UA) (0.5-500 μM) were evaluated to determine their vasorelaxant effect on ex vivo rat aorta ring model. In vivo UA antihypertensive action was determined on spontaneously hypertensive rats.

RESULTS AND DISCUSSION

DEAm induced a significant vasorelaxant effect in concentration-dependent and endothelium-independent manners (EC₅₀=174.276 ± 5.98 μg/mL) by a calcium channel blockade and potassium channel opening. Bio-guided fractionation allowed to isolate acacetin (112 mg), UA (2.830 g), acacetin/oleanolic acid (OA) (M1) (155 mg) and acacetin/OA/UA (M2) (1.382 g) mixtures, which also showed significant vasodilation. UA significantly diminished diastolic (80 mmHg) and systolic blood pressure (120 mmHg), but heart rate was not modified.

CONCLUSION

DEAm produced significant vasorelaxant action by myogenic control cation. The presence of acacetin, OA and UA into the extract was substantial for the relaxant activity of DEAm. In vivo antihypertensive action of UA corroborates the use of A. mexicana as an antihypertensive agent on Mexican folk medicine.

[Functionality of the xoxF Gene in Methylobacterium dichloromethanicum DM4]

Activation of expression of the xoxFgene encoding PQQ-dependent methanol/ethanol dehydrogenase (METDI2492) in dichloromethane- (DCM) -grown Methylobacterium dichloromethanicum DM4 was first demonstrated. The sequence of the only XoxF homolog found in the genome of strain DM4 exhibited 50% identity to that of the protein (MxaF) of the large subunit of methanol dehydrogenase (MDH). A knockout mutant with the inactivate xoxF gene (ΔxoxF) was found to be unable to grow on methanol due to the absence of the expression of the gene cluster of the classical MDH, as was confirmed by the GFP test. When grown of succinate, the ΔxoxF mutant exhibited a lower growth rate on DCM than the original strain and was more sensitive to various stress factors (oxidative, osmotic, and heat shock). Based on these data, the xoxF gene was hypothesized to belong to a group of genes affecting expression of the proteins of general stress response.

Xanthone-rich dichloromethane fraction of Securidaca inappendiculata, the possible antirheumatic material base with anti-inflammatory, analgesic, and immunodepressive effects

CONTEXT

Securidaca inappendiculata Hassk. is an traditional Chinese medicine curing rheumatoid arthritis, but there is a lack of reports on material base research.

OBJECTIVE

To find the active fraction of S. inappendiculata contributing the most to antirheumatic activity.

MATERIALS AND METHODS

Prior to assays in vivo, mice were treated with different fractions from S. inappendiculata for 5 d at doses relative to 10, 5, and 2.5 g/kg of crude drug. Hot plate test and carrageenan-induced paw edema test were used to investigate analgesic and anti-inflammatory activities. PGE2 levels in inflammatory paws were determined by a colorimetric method. Carbon clearance test in vivo and lymphocyte transformation test in vitro were employed to assess the immune regulation activity. HPLC was used to explore the main compounds in the active fraction.

RESULTS

All the fractions, especially the dichloromethane fraction (SID), alleviated inflammation. High dose of SID (112 mg/kg) inhibited paw swelling by 63.1%, and decreased PGE2 level to 38 ng/mL. The ethyl acetate fraction (SIE) and SID suppressed the carbon clearance rate (K = 0.044, 0.038 for high dose) efficiently. All fractions hindered the transformation and proliferation of lymphocyte, and prolonged the reaction time of rats in the hot plate test. The concentrations of two typical xanthones: 2-hydroxyl-1,7-dimethoxyl-xanthone and 1,7-dihydroxyl-xanthone in SID were 0.93% and 1.19%, respectively, by HPLC analysis.

CONCLUSION

SID exhibited significant anti-inflammatory, analgesic, and immunodepressive effects in vivo and vitro, and deemed as the main material base for the antirheumatic activity.

Carbon monoxide may enhance bile secretion by increasing glutathione excretion and Mrp2 expression in rats

BACKGROUND

Nitric oxide (NO) donors have been reported to induce choleresis via an increased excretion of glutathione. The effects of another gas molecule, carbon monoxide (CO), on bile formation are, however, inconsistent among previous reports. We investigated the sequential changes of bile output and the biliary contents in rats with or without CO supplementation to elucidate the mechanism of CO on bile excretion.

METHODS

Dichloromethane (DCM) was gastrically fed to male Sprague-Dawley rats to yield CO by liver biotransformation. The rats were divided into DCM-treated (n = 7), DCM plus L-NAME-treated (n = 6), and corn oil-treated-(n = 8) groups. Bile samples were collected hourly to examine the flow rate and bile content. Serum levels of nitrite and nitrate 4 hours after DCM supplementation with or without NO synthase (NOS) inhibition were measured by capillary electrophoresis. The expression of hepatic inducible NOS was evaluated by Western blotting 6 hours after DCM administration.

RESULTS

Levels of carboxyhemoglobin rose to around 10% at 4 hours after DCM supplementation and were maintained until the end of the experiments. Bile flow increased after DCM supplementation and was associated with a concomitant increase of biliary glutathione and higher hepatic multidrug resistance-associated protein 2 (Mrp2) expression. Hepatic inducible NOS expression and serum nitrate/nitrite levels were also increased. Treatment with an NOS inhibitor (L-NAME) abolished the CO-induced glutathione excretion and choleresis, but not Mrp2 expression.

CONCLUSION

The present study demonstrated that CO enhanced biliary output in conjunction with NO by increasing the biliary excretion of glutathione. The increment in biliary glutathione was associated with an increased expression of hepatic Mrp2.

Assessment of anxiolytic and panicolytic effects of dichloromethane fraction from stems of Kielmeyera coriacea

Kielmeyera coriacea Mart. (Calophyllaceae) is known popularly as "Pau Santo". The hydroethanolic extract (HE) of Kielmeyera coriacea stems and its semi-pure dichloromethane (DCM) constituent produced an antidepressant-like effect in rats. The purpose of this study was to investigate the effects of repeated administration (21 days) by gavage of the DCM fraction (5, 10 or 15mg/kg) in rats submitted to the elevated T-maze (ETM), a model of generalized anxiety and panic disorders. The tricyclic antidepressant imipramine (15mg/kg) was used as a positive control. Rat locomotion was assessed using the open field test (OFT) following each drug treatment. The 2-hydroxy-1-methoxyxanthone (1), aucuparin (2), swertinin (3), 1,3,7-trihydroxy-2-(3-methylbut-2-enyl)-xanthone (4) and 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)-xanthone (5) were identified in DCM fraction, and suggest that the xanthone (4) is related with the antidepressant-like profile of this plant. Pharmacological evaluation showed that DCM fraction (10 and 15 mg/kg) decreased the inhibitory avoidance latency from the closed arm and increased the one-way escape latency from the open arm in the ETM, which is indicative of anxiolytic and panicolytic effects, respectively, as occurs with the positive control, imipramine (15 mg/kg), when compared to their control group (vehicle). Locomotor activity was not significantly altered by the different treatments. This study suggests that the DCM fraction from stems of Kielmeyera coriacea can be an important therapeutic alternative in the treatment of anxiety disorders, such as generalized anxiety and panic disorders.

Effect of organic-phase solvents on physicochemical properties and cellular uptake of astaxanthin nanodispersions

A simplex centroid mixture design was used to study the interactions between two chosen solvents, dichloromethane (DCM) and acetone (ACT), as organic-phase components in the formation and physicochemical characterization and cellular uptake of astaxanthin nanodispersions produced using precipitation and condensation processes. Full cubic or quadratic regression models with acceptable determination coefficients were obtained for all of the studied responses. Multiple-response optimization predicted that the organic phase with 38% (w/w) DCM and 62% (w/w) ACT yielded astaxanthin nanodispersions with the minimum particle size (106 nm), polydispersity index (0.191), and total astaxanthin loss (12.7%, w/w) and the maximum cellular uptake (2981 fmol/cell). Astaxanthin cellular uptake from the produced nanodispersions also showed a good correlation with their particle size distributions and astaxanthin trans/cis isomerization ratios. The absence of significant (p > 0.05) differences between the experimental and predicted values of the response variables confirmed the adequacy of the fitted models.

Interference of Thai traditional medicine (Yahom Ampanthong) on hepatic cytochrome P450 enzymes and pentobarbital-induced sleeping in mice

Yahom Ampanthong, a Thai traditional medicine, is commonly used for treatment of nausea, vomiting and syncope. Its formula is composed of more than 10 medicinal plants. Currently, the herbal-drug interactions were reported among the case of co-administration of traditional and Western medicines, since cytochrome P450 enzymes involve in drug metabolism and affect the drug action. This study aimed to investigate the effects of Yahom extracts on hepatic cytochrome P450 enzymes and pentobarbital-induced sleeping in mice. Powder of Yahom Ampanthong was extracted with three different solvents, i.e., dichloromethane, methanol and distilled water. The activities of CYP1A1, CYP1A2, CYP2B, CYP2E1 and CYP3A4 were determined after the administration of Yahom extracts for 4 weeks. All three extracts significantly inhibited CYP1A1, CYP1A2, CYP2E1 activities. In contrast, only dichloromethane and methanol extracts enhanced CYP2B activity. However, all three extracts did not affect CYP3A4 activity. When compared to the control group, the dichloromethane extract-treated animals showed shorter pentobarbital-induced sleeping time after treatment for 1 and 4 weeks. In conclusion, Yahom Ampanthong extracts modulated hepatic microsomal cytochrome P450 activities and decreased the pentobarbital-induced sleeping time. Therefore, the concomitant administration of Yahom with certain drugs may give rise to the herbal-drug interaction, which may affect the clinical implication of drug actions.

Antimicrobial activity of the dichloromethane extract from in vitro cultured roots of Morinda royoc and its main constituents

The dichloromethane extract and seven anthraquinones isolated from in vitro cultured roots of Morinda royoc L. were tested for their antimicrobial activity against seven yeast and seven bacterial strains. The extract showed a minimum inhibitory concentration (MIC) value of 15.6 microg/m against all species of Candida tested; except C. glabrata (MIC 1.95 microg/mL), and it inhibited the growth of oxacillin-resistant Staphylococcus aureus (MIC 31.2 microg/mL). Only morindone showed activity against all yeast strains (MIC 1.9 microg/mL), and against oxacillin-resistant Staphylococcus aureus (MIC 15 microg/mL).

Anti-acne-inducing bacterial activity of mangosteen fruit rind extracts

OBJECTIVE

The aims of this study were to determine the most effective solvent extract of mangosteen, anti-acne- inducing bacterial activity and the amount of alpha-mangostin, a major active component in each mangosteen fruit rind extract, using high-performance liquid chromatography (HPLC).

MATERIALS AND METHODS

The fruit rinds of mangosteen were extracted with hexane, dichloromethane, ethanol and water. The extracts were tested for antibacterial activity against bacteria that induce acne, including Propionibacterium acnes and Staphylococcus epidermidis. Thin-layer chromatographic autobiography against these bacteria was also performed for each extract, while the alpha-mangostin content was analyzed using a validated HPLC method.

RESULTS

The dichloromethane extract exhibited the strongest antibacterial effect with minimum inhibitory concentration values for both bacterial species at 3.91 microg/ml, while the minimum bactericidal concentration values against P. acnes and S. epidermidis were 3.91 and 15.63 microg/ml, respectively. Thin-layer chromatographic autobiography indicated that alpha-mangostin was present in all extracts, except the water extract, and is a major active component against both P. acnes and S. epidermidis. Using HPLC, the dichloromethane extract yielded the highest content (46.21% w/w) of alpha-mangostin followed by the ethanol extract (18.03% w/w), the hexane extract (17.21% w/w) and the water extract (0.54% w/w).

CONCLUSIONS

Dichloromethane extract exhibited the strongest anti-acne-inducing bacterial effect and this extract yielded the highest amount of alpha-mangostin.

[Effect of methylene chloride upon hepatic ischemic reperfusion injury]

OBJECTIVE

To investigate the effects and mechanisms of methylene chloride (MC) in hepatic ischemic reperfusion injury.

METHODS

Eighty SD-rats were divided equally into 4 groups: control group (n = 20), donors without any treatment; CoPP group (n = 20), donors injected with CoPP (5 mg/kg, ip) at 24 h; ZnPP group (n = 20), donors injected with ZnPP (20 mg/kg, ip) at 24 h; MC group (n = 20), donors fed with MC (500 mg/kg) per day for 7 days before graft procurement. Syngeneic orthotopic liver transplantation was performed in rats with modified Kamada's two-cuff technique. And SD rats were used as donors (n = 10)and recipients respectively. 5 recipients in each group were sacrificed and the grafts were procured at day 3 after transplantation, the post-operative survival time was observed in the remnant. The tests were determined as following: the level of serum ALT, AST in recipients; heme oxygenase-1 (HO-1) expression of graft was tested by immunohistochemistry and Western blot; the index of graft apoptosis examined by TUNEL method; the pathology of graft assessed by Suzuki's criteria.

RESULTS

The level of serum ALT [(65 +/- 28) U/L], AST [(187 +/- 43) U/L] in CoPP and ALT [(75 +/- 16) U/L], AST [(185 +/- 42) U/L] in MC group was significantly lower than that ALT [(346 +/- 45) U/L], AST [(474 +/- 90) U/L] in control group and ALT [(578 +/- 75) U/L], AST [(1084 +/- 128) U/L] in ZnPP group (P < 0.01). The median expression of HO-1 in MC group was no significantly different with that in control group (P > 0.05). While the median expression of HO-1 in CoPP group was higher than that in control group (P < 0.05). The index of graft apoptosis in MC group and CoPP group, 4.1% +/- 0.6% and 3.2% +/- 0.8% respectively, was significantly lower than that (12.5% +/- 2.4%) in control group and (25.8% +/- 3.1%) in ZnPP group (P < 0.05). Compared with the other two groups, MC and CoPP groups had lesser neutrophil infiltration and a lower grade of hepatocytic injury in grafts. Suzuki's scores in grafts of MC and CoPP groups were lower than that in control and ZnPP groups (P < 0.05). The median post-transplantation survival time of the recipients in MC and CoPP groups was 100 and 93 days respectively while that in control and ZnPP groups was 85 and 12 days (P < 0.05).

CONCLUSION

Over-expression of HO-1 and MC both have protective effects in hepatic ischemic reperfusion injury.

The mechanism of surface-indented protein-loaded PLGA microparticle formation: the effects of salt (NaCl) on the solidification process

The purpose of this study was to evaluate ovalbumin (OVA) leakage pathways and to explore the mechanism of the surface-indented microparticle formation in the preparation of OVA-loaded microparticles. OVA-loaded poly (D,L-lactic-co-glycolic acid) (PLGA) microparticles were prepared by a water-in oil-in water (w/o/w) solvent evaporation method associated with varied NaCl (NaCl) concentrations and adjusted with urea at 1240mOsm kg(-1) in the external aqueous phase. To evaluate dichloromethane (DCM)-related OVA leakage, three stirring rates, 600, 800, 1000rpm at 25 degrees C were carried out during the solvent evaporation stage. Both DCM and OVA levels in the external phase medium and total dispersion were sampled and measured. The time course of particle characteristics was evaluated by microscopy or SEM photography. The surface adsorptive capacities of the prepared microparticles were measured by using bovine serum albumin conjugated with fluorescein isothiocyanate (FITC-BSA). The findings were that the DCM-related OVA leakage accounted for approximately 34%, of the total leakage. By combining NaCl in the external phase, a faster solidifying crust-like structure was formed as a barrier to remarkably reduce OVA loss and improve OVA content from 40.1 to 72.8 microg mg(-1). The yield and OVA content for formulations containing NaCl were much improved by the ionic effect, in addition to the osmotic effect. The total entrapment efficiency was also highly increased from 43 to 72%. The formations of the crust-like surface structure of the microparticle were affected by entrapped drugs, salt content in the external phase and aqueous volume in the inner phase. A scheme was proposed to interpret the formation mechanism of the surface-indented microparticles. In comparison to the surface-smooth microparticles, the surface adsorptive capacities of the surface-indented microparticles were highly improved from 26.6 to 87.0%, determined by the adsorption of FITC-BSA.

Scent may signal fighting ability in male Iberian rock lizards

Intrasexual competition favours the evolution of conspicuous fighting ability badges. However, in spite of the fact that chemoreception is important in sexual selection of many animals, such as lizards, the role of chemical signals in males' contests is relatively unknown. Here, we show that proportions of cholesterol in femoral gland secretions of male Iberian rock lizards were related to their body size (which confers a competitive advantage in fights). Males discriminated chemically and responded aggressively to cholesterol stimuli presented on swabs. Moreover, we experimentally increased cholesterol in the scent of males, and staged encounters in neutral cages between two unfamiliar and size-matched males. Focal males lost more agonisitic interactions against males manipulated with cholesterol than in control tests. We suggest that differences in scent composition may reliably signal fighting ability in many lizard species, which would help to avoid the costs of fighting.

A fraction of methylene chloride from Geum japonicum Thunberg inhibits tumor metastatic and angiogenic potential

The plant Geum japonicum Thunberg (GjT) has been used as a diuretic in traditional medicine. Herein, we report that the GjT extract blocks both the spread of human umbilical vein endothelial cells (HUVECs) on matrigel and the migration of B16 cells. We used various assays to test for cell attachment, spreading, wound healing and angiogenesis. A reverse transcription-polymerase chain reaction (RT-PCR) and a mitogen-activated protein kinase (MAPK) assay were also carried out for the mechanistic study of GjT. Our results showed that a fraction of methylene chloride fraction from GjT inhibited B16 cells during cell attachment and migration and suppressed tube formation in a dose-dependent manner. An RT-PCR analysis showed that the methylene chloride extract decreased the mRNA expression of CD44 and TIMP-2. A Western blot analysis of the phosphorylation of MAPK kinases (ERK, JNK and p38) showed that the GjT fraction increased the expression of phospho-JNK, suggesting that GjT has the potential to alleviate metastatic and angiogenic activity, via a phospho-JNK signaling pathway.

Xanthones with quinone reductase-inducing activity from the fruits of Garcinia mangostana (Mangosteen)

Bioactivity-guided fractionation of a dichloromethane-soluble extract of Garcinia mangostana fruits has led to the isolation and identification of five compounds, including two xanthones, 1,2-dihydro-1,8,10-trihydroxy-2-(2-hydroxypropan-2-yl)-9-(3-methylbut-2-enyl)furo[3,2-a]xanthen-11-one (1) and 6-deoxy-7-demethylmangostanin (2), along with three known compounds, 1,3,7-trihydroxy-2,8-di-(3-methylbut-2-enyl)xanthone (3), mangostanin (4), and alpha-mangostin (5). The structures of compounds 1 and 2 were determined from analysis of their spectroscopic data. All isolated compounds in the present study together with eleven other compounds previously isolated from the pericarp of mangosteen, were tested in an in vitro quinone reductase-induction assay using murine hepatoma cells (Hepa 1c1c7) and an in vitro hydroxyl radical antioxidant assay. Of these, compounds 1-4 induced quinone reductase (concentration to double enzyme induction, 0.68-2.2microg/mL) in Hepa 1c1c7 cells and gamma-mangostin (6) exhibited hydroxyl radical-scavenging activity (IC50, 0.20microg/mL).

A new activating role for CO in cardiac mitochondrial biogenesis

To investigate a possible new physiological role of carbon monoxide (CO), an endogenous gas involved in cell signaling and cytotoxicity, we tested the hypothesis that the mitochondrial generation of reactive oxygen species by CO activates mitochondrial biogenesis in the heart. In mice, transient elevations of cellular CO by five- to 20-fold increased the copy number of cardiac mitochondrial DNA, the content of respiratory complex I-V and interfibrillar mitochondrial density within 24 hours. Mitochondrial biogenesis is activated by gene and protein expression of the nuclear respiratory factor 1 (NRF1) and NRF2, of peroxisome proliferator-activated receptor gamma co-activator-1α, and of mitochondrial transcription factor A (TFAM), which augmented the copy number of mitochondrial DNA (mtDNA). This is independent of nitric oxide synthase (NOS), as demonstrated by the identical responses in wild-type and endothelial NOS (eNOS)-deficient mice, and by the inhibition of inducible NOS (iNOS). In the heart and in isolated cardiomyocytes, CO activation involved both guanylate cyclase and the pro-survival kinase Akt/PKB. Akt activation was facilitated by mitochondrial binding of CO and by production of hydrogen peroxide (H2O2). Interference with Akt activity by blocking PI 3-kinase and by mitochondrial targeting of catalase to scavenge H2O2 prevented binding of NRF1 to the Tfam promoter, thereby connecting mitochondrial H2O2 to the pathway leading to mtDNA replication. The findings disclose mitochondrial CO and H2O2 as new activating factors in cardiac mitochondrial biogenesis.

Induction of carbon monoxide in donor animals prior to organ procurement reduces graft immunogenicity and inhibits chronic allograft dysfunction

BACKGROUND

Nonspecific inflammatory damages occurring prior to organ transplantation reduce long-term graft survival. Here, we tested the beneficial effects of carbon monoxide (CO) induction by methylene chloride (MC).

METHODS

Fischer-344 (F-344 Rat) or Dark Agouti (DA Rat) donor animals were either treated with MC four hours prior to organ removal or remained untreated. Kidneys were transplanted into Lewis (LEW) recipients. The low responder strain combination (F-344-->LEW) was studied for long-term graft changes. Dendritic cells (DCs) migration and early changes were followed in additional groups of a high responding donor/recipient strain combination (DA-->LEW). Native kidneys of uninephrectomized, age-matched normal animals served as controls.

RESULTS

Following MC application COHb peaked within two hours in donor animals. Renal function and morphology improved significantly in renal allografts of CO induced donor animals and were comparable to native controls long-term (24 wks). Early after transplantation (24 hr) donor-derived DCs, CD4+ T-cells and alloreactive T-cells were significantly reduced following the engraftment of organs from treated donors. In addition, a trend towards a Th1/Th2 shift and a significant intragraft reduction of CD3 mRNA expression was observed.

CONCLUSION

Donor treatment for the induction of CO reduced graft immunogenicity and inhibited chronic allograft nephropathy.

Induction of carbon monoxide in the donor reduces graft immunogenicity and chronic graft deterioration

Chronic allograft dysfunction remains the major obstacle for long-term successful transplantation. To date there is no effective treatment. Overexpression of protective genes has provided increased graft function and survival. This mechanism has been implicated in the process of graft accommodation. One of these genes that has been shown to mediate protective effects decodes the enzyme heme oxygenase-1 (HO-1), and an HO-1 downstream product, carbon monoxide (CO). Using an established model of kidney chronic allograft rejection in the rat, we investigated the impact of methylene chloride (MC), a CO donor, as a therapeutic tool to reduce chronic graft deterioration. We showed that donor and long-term recipient treatment with MC improved graft function and reduced histological signs of chronic rejection. Carbon monoxide may be a promising agent to improve graft quality and long-term graft function.

[Effect of DNA-damaging agents on the aerobic methylobacteria capable and incapable of utilizing dichloromethane]

Methylobacterium dichloromethanicum DM4, a degrader of dichloromethane (DCM), was more tolerant to the effect of H2O2 and UV irradiation than Methylobacterium extorquens AM1, which does not consume DCM. Addition of CH2Cl2 to methylobacteria with active serine, ribulose monophosphate, and ribulose bisphosphate pathways of C1 metabolism, grown on methanol, resulted in a 1.1- to 2.5-fold increase in the incorporation of [alpha-32P]dATP into DNA Klenow fragment (exo-). As DCM dehalogenase was not induced in this process, the increase in total lengths of DNA gaps resulted from the action of DCM rather than S-chloromethylglutathione (intermediate of primary dehalogenation). The degree of DNA damage in the presence of CH2Cl2 was lower in DCM degraders than methylobacteria incapable of degrading this pollutant. This suggests that DCM degraders possess a more efficient mechanism of DNA repair.

Autoinduction in Erwinia amylovora: evidence of an acyl-homoserine lactone signal in the fire blight pathogen

Erwinia amylovora causes fire blight disease of apple, pear, and other members of the Rosaceae. Here we present the first evidence for autoinduction in E. amylovora and a role for an N-acyl-homoserine lactone (AHL)-type signal. Two major plant virulence traits, production of extracellular polysaccharides (amylovoran and levan) and tolerance to free oxygen radicals, were controlled in a bacterial-cell-density-dependent manner. Two standard autoinducer biosensors, Agrobacterium tumefaciens NTL4 and Vibrio harveyi BB886, detected AHL in stationary-phase cultures of E. amylovora. A putative AHL synthase gene, eamI, was partially sequenced, which revealed homology with autoinducer genes from other bacterial pathogens (e.g., carI, esaI, expI, hsII, yenI, and luxI). E. amylovora was also found to carry eamR, a convergently transcribed gene with homology to luxR AHL activator genes in pathogens such as Erwinia carotovora. Heterologous expression of the Bacillus sp. strain A24 acyl-homoserine lactonase gene aiiA in E. amylovora abolished induction of AHL biosensors, impaired extracellular polysaccharide production and tolerance to hydrogen peroxide, and reduced virulence on apple leaves.

In vitro investigation of the toxic effects of extracts of Allium sativum bulbs on adults of Hyalomma marginatum rufipes and Rhipicephalus pulchellus

The toxic effects of the extracts of Allium sativum (Garlic) were evaluated against adults of Hyalomma marginatum rufipes and Rhipicephalus pulchellus using three types (Types A, B and C) of contact toxicity bioassays. A. sativum bulbs were extracted with acetone, ethanol and dichloromethane (DCM) solvents. Among these three solvents, it is the DCM extract of A. sativum that appears to have anti-tick activity. In the Type A contact toxicity bioassay, DCM extracts of A. sativum demonstrated a high acaricidal bioactivity against H. m. rufipes with 100 % of ticks killed in less than an hour, and toxicity persisted to the second day. A weak acaricidal activity of aqueous extracts of A. sativum was observed in the Type B contact toxicity bioassay. In the Type C contact toxicity bioassay, a concentration of 24 % w/v of DCM extracts of garlic in sunflower oil (Helianthus annuus) had killed 100% of H. m. rufipes (LC50= 5.9 % w/v) and R. pulchellus (LC50 = 10.3 % w/v) by 24 hours post-treatment of ticks. The results obtained from this study suggest that DCM extract of A. sativum is a potential source of novel acaricidal agents.

In vitro antiprotozoal activity from the roots of Geranium mexicanum and its constituents on Entamoeba histolytica and Giardia lamblia

This paper examines the antiprotozoal activity of the dichloromethane-MeOH extract, fractions and pure compounds from the roots of Geranium mexicanum on Entamoeba histolytica and Giardia lamblia. The result indicated that the extract, organic fraction and a pure flavonoid were active against both protozoa with IC50 values ranging from 1.9 to 79.2 microg/ml for Entamoeba histolytica and from 1.6 to 100.4 microg/ml in the case of Giardia lamblia. The main active compound was the flavan-3-ol, (-)-epicatechin. In addition, the moderate active compounds (+)-catechin, tyramine and beta-sitosterol 3-O-beta-D-glucopyranoside, also were isolated. These results support the anecdotal reports for the traditional use of Geranium mexicanum roots in the management of diarrhoea and dysentery, illnesses caused in some cases by enteric protozoa.

The effects of extracts from anti-diarrheic Thai medicinal plants on the in vitro growth of the intestinal protozoa parasite: Blastocystis hominis

The activities of n-hexane, dichloromethane and methanol extracts from five anti-diarrheic Thai medicinal plants, Acacia catechu (Fabaceae) resin, Amaranthus spinosus (Amaranthaceae) whole plant, Brucea javanica (Simaroubaceae) seed, Piper longum (Piperaceae) fruit and Quercus infectoria (Fagaceae) nut gall were tested against the in vitro growth of fresh isolates of the intestinal protozoan parasite, Blastocystis hominis. The extracts at concentrations that ranged from 62.5 to 2000 microg/mL, were incubated with several isolates of Blastocystis hominis for 48 h. The activities were classified as killed, inhibited, moderately inhibited and not-inhibited. Dichloromethane and methanol extracts from the Brucea javanica seed and a methanol extract from Quercus infectoria nut gall showed the highest activity. At a concentration of 2000 microg/mL, the three extracts killed 82, 75 and 67% of the Blastocystis hominis samples tested and inhibited 94, 100 and 76% of them, respectively. Metronidazole, used as a reference antiprotozoan drug, at a concentration of 40 microg/mL, killed 97% of the Blastocystis hominis isolates and inhibited all samples tested at concentrations that ranged from 1.25 to 20 microg/mL.

Establishment of new preparation method for solid dispersion formulation of tacrolimus

The aim of this study was to establish a new preparation method for solid dispersion formulation (SDF) of tacrolimus, a poorly water-soluble drug, without dichloromethane, because no use of dichloromethane is recommended by ICH harmonized tripartite guideline. To select the appropriate carrier, three different SDFs with polyethylene glycol 6000 (PEG 6000), polyvinylpyrrolidone (PVP) and hydroxypropylmethylcellulose (HPMC) were prepared by the conventional solvent method, in which tacrolimus and the carrier were completely dissolved in the mixture of dichloromethane and ethanol. Powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) patterns indicated that tacrolimus exists in an amorphous state in all three SDFs. The supersaturated dissolution profiles of tacrolimus were observed in all SDFs, and the highest level of supersaturation for tacrolimus was obtained and maintained for 24h from SDF with HPMC. On the other hand, the supersaturated level from SDF with PEG 6000 or PVP decreased rapidly. The in vivo oral absorption study in dogs showed that bioavailability of tacrolimus from SDF with HPMC was remarkably improved compared with the crystalline powder. It was clarified that HPMC is the most appropriate carrier for SDF of tacrolimus. Then, SDF of tacrolimus was prepared by the new method, which allows us to make SDF of tacrolimus by swelling HPMC with ethanol, in which tacrolimus was completely dissolved. This new method does not need dichloromethane. The physicochemical properties of SDF with HPMC prepared by the new method were the same as those of SDF prepared by the conventional solvent method. Furthermore, SDF with HPMC prepared by the new method was still stable after stored at 40 degrees C for 3 months. The pharmacokinetic parameters after oral administration in monkeys showed no significant difference (P>0.01) between SDFs with HPMC prepared by the two methods. In conclusion, we have established the new preparation method for SDF of tacrolimus with HPMC and the new method makes it possible to prepare SDF of tacroliumus without dichloromethane.

Inhibitory activity of flavonoids fromPrunus davidiana and other flavonoids on total ROS and hydroxyl radical generation

Since reactive oxygen species (ROS) and hydroxyl radicals (*OH) play an important role in the pathogenesis of many human degenerative diseases, much attention has focused on the development of safe and effective antioxidants. Preliminary experiments have revealed that the methanol (MeOH) extract of the stem of Prunus davidiana exerts inhibitory/scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, total ROS and peroxynitrites (ONOO-). In the present study, the antioxidant activities of this MeOH extract and the organic solvent-soluble fractions, dichloromethane (CH2Cl2), ethyl acetate (EtOAc), and n-butanol (n-BuOH), and the water layer of P. davidiana stem were evaluated for the potential to inhibit *OH and total ROS generation in kidney homogenates using 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA), and for the potential to scavenge authentic ONOO-. We also evaluated the inhibitory activity of seven flavonoids isolated from P. davidiana stem, kaempferol, kaempferol 7-O-beta-D-glucoside, (+)-catechin, dihydrokaempferol, hesperetin 5-O-beta-D-glucoside, naringenin and its 7-O-beta-D-glucoside, on the total ROS, *OH and ONOO- systems. For the further elucidation of the structure-inhibitory activity relationship of flavonoids on total ROS and *OH generation, we measured the antioxidant activity of sixteen flavonoids available, including three active flavonoids isolated from P. davidiana, on the total ROS and *OH systems. We found that the inhibitory activity on total ROS generation increases in strength with more numerous hydroxyl groups on their structures. Also, the presence of an ortho-hydroxyl group, whether on the A-ring or B-ring, and a 3-hydroxyl group on the C-ring increased the inhibitory activity on both total ROS and *OH generation.

Mutagenic activity of airborne particulate matter as an indicative measure of atmospheric pollution

Mutagenic activity of organic extracts of airborne particulate matter at four different sites within the urban area of the city of Porto Alegre, Brazil, was investigated using the Salmonella/microsome assay, with the Kado microsuspension method. The extracts were obtained by sonication, sequentially extracted according to polarity, with cyclohexane (CX) and dichloromethane (DCM) solvents. The different fractions were tested for mutagenicity with the Salmonella typhimurium strains TA98, TA98NR and TA98/1,8-DNP6, without S9 mix metabolic activation. A positive frameshift mutagenic response was observed for non-polar (CX) and/or moderately polar (DCM) compounds at the different sites. The responses varied at different seasons of the year, and the highest revertants per m3 (rev/m3) values were observed at the site subject to the strongest influence of automotive vehicles (site 3) in spring (17.13 rev/m3) in DCM fractions, and in summer (13.01 rev/m3) in CX fractions. The responses observed for the TA98NR and TA98/1,8-DNP6 strains suggest the contribution of nitrocompounds to the mutagenic activity observed. Although there appears to be an indicative association between the increased mass per unit volume of air (TSP) and the mutagenicity of organic extracts of airborne particulate matter in the present study, the Salmonella/microsome assay was a sensitive method to define areas contaminated by genotoxic compounds, even in samples that present TPS values acceptable by the environmental quality standards established by law.

Reconstitution of recombinant uncoupling proteins: UCP1, -2, and -3 have similar affinities for ATP and are unaffected by coenzyme Q10

The successful development of recombinant expression and reconstitution protocols has enabled a detailed study of the transport properties and regulation of the uncoupling proteins (UCP). We optimized conditions of isolation and refolding of bacterially expressed uncoupling proteins and reexamined the transport properties and regulation of bacterially expressed UCP1, -2, and -3 reconstituted in liposomes. We show for the first time that ATP inhibits UCP1, -2, and -3 with similar affinities. The Ki values for ATP inhibition were 50 microm (UCP1), 70 microm (UCP2), and 120 microm (UCP3) at pH 7.2. These affinities for ATP are similar to those obtained with native UCP1 isolated from brown adipose tissue mitochondria (Ki = 65 microm at pH 7.2). The Vmax values for proton transport were also similar among the UCPs, ranging from 8 to 20 micromol.min(-1).mg(-1), depending on experimental conditions. We also examined the effect of coenzyme Q on fatty acid-catalyzed proton flux in liposomes containing recombinant UCP1, -2, and -3. We found that coenzyme Q had no effect on the fatty acid-dependent proton transport catalyzed by any of the UCPs nor did it affect nucleotide regulation of the UCPs. We conclude that coenzyme Q is not a cofactor of UCP-mediated proton transport.

Photoactive extracts from Thevetia peruviana with antifungal properties against Cladosporium cucumerinum

Seeds of Thevetia peruviana were screened for their antifungal photoactivity. Extracts obtained either with n-hexane or dichloromethane were fractionated by column chromatography and further analysed by thin-layer chromatography. All seed extracts and fractions were tested for inhibition of the fungus Cladosporium cucumerinum for the evaluation of photoactive inhibitory effects. Antifungal light-dependent activity was observed for some of the fractions and both crude extracts. The most photoactive fraction was analysed by capillary gas chromatography with mass spectrometry in order to identify its constituents. Two major groups of compounds were identified, terpenes and fatty acids and derivatives. Pulegone, linoleic acid and palmitic acid were the major compounds. Terpenes seem to be the major substances with antifungal photoactivity.

Inhalant abuse in the pediatric population: a persistent challenge

Inhalants remain one of the most commonly abused substances by adolescents in the United States today. Recent epidemiologic studies have demonstrated a decrease in the prevalence of inhalant abuse, but overall rates remain high. Inhalants have the potential to result in serious organ system dysfunction or even sudden death. This article reviews the most recent epidemiologic data on inhalant abuse, summarizes the types of substances used and their mechanism of actions, and discusses clinical toxicity and medical management.

Comparison of in vitro and in vivo bioassays for estrogenicity in effluent from North American municipal wastewater facilities

Attempts to better understand causal factors affecting estrogenicity in municipal wastewater have primarily focused on analytical evaluation of specific chemical estrogens and the use of estrogen receptor (ER) based in vitro assays. To compare analytical,in vitro, and in vivo assays for estrogenicity, wastewater from four New York and one Texas municipal wastewater facilities was evaluated for estrogenic activity using the yeast estrogen screen assay (YES) and an in vivo fish vitellogenin (VTG) assay. Estrogenic activity, as measured by the YES assay, was observed in methanol and/or methylene chloride eluents from C18 extracts in two of the New York treatment facilities and the Texas facility. Estradiol equivalents for the YES assay data ranged from </=1 to 15 ng/l. Male Japanese medaka (Oryzias latipes) were then exposed for 7 days to solvent extracts from the New York-Red Hook facility and the Texas facility. Hepatic and plasma vitellogenin were induced in medaka after exposure to the methanol eluent from the New York facility, even though the YES assay indicated that both the methanol and methylene chloride eluents were estrogenic. Whereas an estrogenic response in the YES assay was only observed in the methanol eluent from the Texas facility, plasma VTG induction was observed in both the methanol and methylene chloride eluents. In vivo estrogenic activity was nearly 10-fold greater than YES activity indicating the presence of nonestrogen receptor ligands that elicit estrogenic effects in fish through indirect mechanisms. The sole use of in vitro assays to screen for estrogenicity may underestimate estrogenic potential of wastewater.

Effects of VOCs on herbaceous plants in an open-top chamber experiment

A selection of herbaceous plants representing the ground flora around a typical chemical installation in the UK was exposed continuously for 7 weeks to a mixture of six VOCs (acetone, acetonitrile, dichloromethane, ethanol, methyl t-butyl ether and toluene) in open-top chambers. Exposure concentrations were based on predictions of atmospheric dispersion from a single source, at a distance of approximately 2 km. The effects of continuous exposure, representing a worst-case, were measured in terms of uncontrolled water loss from leaves, leaf wettability, chlorophyll content and fluorescence, dry matter production and detailed observations of changes in plant growth and phenology. There were significant effects of VOC exposure on seed production, leaf water content and photosynthetic efficiency in some plant species. Such effects may be detectable in vegetation close to major industrial point sources of VOCs, or as a result of an accidental release of material during manufacture or transport. Some of the species tested e.g. birdsfoot trefoil (Lotus corniculatus L.) seem to be promising as potential bioindicators for VOCs, but there may be other even more sensitive species waiting to be discovered. However, the most obvious and conveniently measured response to VOCexposure in the birdsfoot trefoil (premature senescence i.e. advanced timing of seed pod production) could easily be confused in the field with climatic influences. It is also uncertain at this stage whether any of the effects observed would lead to longer term ecological changes in natural plant communities, through biased competition between sensitive and more tolerant species.

Characterization of urinary volatiles in Swiss male mice (Mus musculus): bioassay of identified compounds

The present study was carried out to investigate the chemical nature of the urine of male mice and to assess its bioactivity. Urine of mature male mice was extracted with dichloromethane (1 : 1 ratio v/v) and analysed by gas-chromatography linked mass-spectrometry (GC-MS). Ten different compounds such as alkanes, alcohols, etc. were detected in the urine. Among the ten, five compounds are specific to males namely, 3-cyclohexene-1-methanol (I), 3-amino-s-triazole (II), 4-ethyl phenol (III), 3-ethyl-2,7-dimethyl octane (IV) and 1-iodoundecane (V). The compound, 4-ethylphenol, has been previously reported in several strains of male mice. Furthermore, the compounds (II) and (IV) are closely similar to 2-sec-butylthiazole and dehydro-exo-brevicomin compounds which have already been reported in male mice. Bioassay revealed that compounds (II), (III) and (IV) were responsible for attracting females and in inducing aggression towards males, as compared to the other compounds i.e. (I) and (V). The results indicate that these three volatiles (II, III and IV) of male mice appear to act as attractant of the opposite sex.

The proteolytic release of genotoxins from cooked beef

Dietary factors are important in the aetiology of human cancer and carcinogens, mostly heterocyclic aromatic amines, have been isolated from cooked proteinaceous foodstuffs. Whilst such carcinogens have induced tumours in rodent bioassays, the dosages required were much higher than estimates of human exposure levels. We have examined the possibility that genotoxins, which were not extractable prior to enzymic digestion, may be released from cooked beef by proteolysis. Dichloromethane and/or a solid-phase tandem extraction procedure were used with aqueous homogenates of pan-fried or uncooked beef, both before and after proteolysis (proteinase K). Genotoxicity was measured using the alkaline single cell-gel electrophoresis ('Comet') assay in MCL-5 cells and mutagenicity in Salmonella typhimurium strains TA1538 or YG1019. Proteolysis released significant amounts of DNA-damaging material that was not extractible prior to enzymic digestion, suggesting that human exposures to diet-derived genotoxins may have been underestimated.

Method for spiking soil samples with organic compounds

We examined the harmful side effects on indigenous soil microorganisms of two organic solvents, acetone and dichloromethane, that are normally used for spiking of soil with polycyclic aromatic hydrocarbons for experimental purposes. The solvents were applied in two contamination protocols to either the whole soil sample or 25% of the soil volume, which was subsequently mixed with 75% untreated soil. For dichloromethane, we included a third protocol, which involved application to 80% of the soil volume with or without phenanthrene and introduction of Pseudomonas fluorescens VKI171 SJ132 genetically tagged with luxAB::Tn5. For both solvents, application to the whole sample resulted in severe side effects on both indigenous protozoa and bacteria. Application of dichloromethane to the whole soil volume immediately reduced the number of protozoa to below the detection limit. In one of the soils, the protozoan population was able to recover to the initial level within 2 weeks, in terms of numbers of protozoa; protozoan diversity, however, remained low. In soil spiked with dichloromethane with or without phenanthrene, the introduced P. fluorescens VKI171 SJ132 was able to grow to a density 1,000-fold higher than in control soil, probably due mainly to release of predation from indigenous protozoa. In order to minimize solvent effects on indigenous soil microorganisms when spiking native soil samples with compounds having a low water solubility, we propose a common protocol in which the contaminant dissolved in acetone is added to 25% of the soil sample, followed by evaporation of the solvent and mixing with the remaining 75% of the soil sample.

Effects of the aqueous and methylene chloride extracts of Bidens pilosa leaf on fructose-hypertensive rats

We investigated the effects of the aqueous (150-350 mg/kg) and methylene chloride (150-300 mg/kg) extracts of Bidens pilosa on fructose-induced hypertension in rats. Food and liquid intake were measured as well as systolic blood pressure and plasma levels of glucose, insulin, cholesterol, triglycerides and creatinine. Fructose feeding for 6 weeks induced hypertension, hyperinsulinemia and increased plasma triglyceride levels in male Wistar rats. The aqueous and methylene chloride extracts of B. pilosa reversed the high blood pressure and hypertriglyceridemia developed due to fructose feeding but did not have any effects on plasma levels of insulin and glucose. High doses of the extracts reduced plasma creatinine levels and tended to increase plasma cholesterol. These results suggest that the extracts of B. pilosa possess hypotensive effects whose mechanism of action is not related to insulin sensitivity.

Salt and cosolvent effects on ionic drug loading into microspheres using an O/W method

Salt effects on aqueous solubility and microsphere entrapment efficiency of a model ionic drug (quinidine sulfate) were studied. Poly-D,L-lactic acid (PLA) microspheres were prepared using an O/W solvent evaporation method with various electrolytes added in different concentrations to the aqueous phase. Salts affect microsphere drug loading by changing the aqueous solubility of both the drug and the organic solvent (dichloromethane, DCM). Quinidine sulfate solubility was depressed by either a common ion effect (Na(2)SO(4)) or by formation of new, less soluble drug salts (e.g., bromide, perchlorate, thiocyanate) for which solubility products (K(sp)) were estimated. Inorganic salts depress DCM aqueous solubility to different extents as described by the Hofmeister series. NaClO(4) and NaSCN depressed drug solubility to the highest extent, resulting in microspheres with high drug loading (e.g., >90%). Other salts such as Na(2)SO(4) did not depress quinidine sulfate solubility to the same extent and did not improve loading. The use of a cosolvent (ethanol) in the organic phase improved microsphere drug loading and resulted in a uniform microsphere drug distribution with smooth release profiles.

Growth inhibition of Escherichia coli by dichloromethane in cells expressing dichloromethane dehalogenase/glutathione S-transferase

Dichloromethane (DCM) dehalogenase converts DCM to formaldehyde via the formation of glutathione metabolites and generates 2 mol HCl per mol DCM metabolized. Growth of Escherichia coli expressing DCM dehalogenase was immediately and severely inhibited during conversion of 0.3 mM DCM. Intracellular pH (pH(i)) rapidly decreased and chloride ions were steadily released into the medium. Bacterial growth resumed after completion of DCM conversion and cell viability was unaffected. At 0.6 mM DCM there was no recovery from growth inhibition in liquid culture due to the build-up of inhibitory concentrations of formaldehyde. DCM turnover stimulated potassium efflux from cells, which was suppressed by glucose. The potassium efflux, therefore, did not contribute to growth inhibition. It was concluded that initial growth inhibition results from lowering of the cytoplasmic pH, but severity of growth inhibition was greater than expected for the change in pH(i). Possible contributors to growth inhibition are discussed.

DNA polymerase I is essential for growth of Methylobacterium dichloromethanicum DM4 with dichloromethane

Methylobacterium dichloromethanicum DM4 grows with dichloromethane as the unique carbon and energy source by virtue of a single enzyme, dichloromethane dehalogenase-glutathione S-transferase. A mutant of the dichloromethane-degrading strain M. dichloromethanicum DM4, strain DM4-1445, was obtained by mini-Tn5 transposon mutagenesis that was no longer able to grow with dichloromethane. Dichloromethane dehalogenase activity in this mutant was comparable to that of the wild-type strain. The site of mini-Tn5 insertion in this mutant was located in the polA gene encoding DNA polymerase I, an enzyme with a well-known role in DNA repair. DNA polymerase activity was not detected in cell extracts of the polA mutant. Conjugation of a plasmid containing the intact DNA polymerase I gene into the polA mutant restored growth with dichloromethane, indicating that the polA gene defect was responsible for the observed lack of growth of this mutant with dichloromethane. Viability of the DM4-1445 mutant was strongly reduced upon exposure to both UV light and dichloromethane. The polA'-lacZ transcriptional fusion resulting from mini-Tn5 insertion was constitutively expressed at high levels and induced about twofold after addition of 10 mM dichloromethane. Taken together, these data indicate that DNA polymerase I is essential for growth of M. dichloromethanicum DM4 with dichloromethane and further suggest an important role of the DNA repair machinery in the degradation of halogenated, DNA-alkylating compounds by bacteria.

Measurement of urinary free cortisol using the Acs:180 serum cortisol chemiluminescent immunoassay

Measurement of urinary free cortisol using the Bayer Automated Chemiluminescent System (ACS:180 PLUS) was evaluated and compared with an in-house extraction radioimmunoassay (RIA). Inter-assay coefficients of variation were acceptable, being respectively 5.3%, 4.8% and 3.8% at 141, 406 and 942 nmol/L (n=20) for the ACS direct assay and 19.4% and 12.1% at 27 and 116 nmol/L with dichloromethane extraction (n=10). Using tritiated cortisol, mean extraction efficiency for the ACS extraction protocol was 89% compared with 104% for the RIA method (n=6, P<0.001) and using urine spiked with ACS serum calibrator, extraction efficiency was only 76% (standard deviation 8.8%, n=49) on the ACS. Urine spiked with cortisol dissolved in ethanol also gave significantly lower recoveries on the ACS for both direct and extraction methods compared with the RIA. Regression analysis of results from a mixture of control serum samples and samples from patients (n=93) showed good correlations between the direct and extraction ACS methods and the RIA extraction assay. The median concentration in 23 normal subjects and 95% reference intervals (nmol/24 h) were: ACS direct, 237 (135-505); ACS extraction, 91 (33-239); and RIA extraction, 146 (80-334). 5Beta-dihydrocortisol was the only major interferent in all assays. The ACS extraction assay showed acceptable performance and correlated well with the extraction RIA, although there was evidence of matrix-dependent effects causing low recovery.