Exploring the composition and properties of Centella asiatica metabolites and investigating their impact on BSA glycation, LDL oxidation and α-amylase inhibition

Centella asiatica (L.) Urb. is a small herbaceous plant belonging to the Apiaceae family that is rich in triterpenes, such as asiaticoside and madecassoside. Centella asiatica finds broad application in promoting wound healing, addressing skin disorders, and boosting both memory and cognitive function. Given its extensive therapeutic potential, this study aimed not only to investigate the Centella asiatica ethanolic extract but also to analyze the biological properties of its organic fractions, such as antioxidant antiglycation capacity, which are little explored. We also identified the main bioactive compounds through spectrometry analysis. The ethanolic extract (EE) was obtained through a static maceration for seven days, while organic fractions (HF: hexane fraction; DF: dichloromethane fraction; EAF: ethyl acetate fraction; BF: n-butanol fraction and HMF: hydromethanolic fraction) were obtained via liquid-liquid fractionation. The concentration of phenolic compounds, flavonoids, and tannins in each sample was quantified. Additionally, the antiglycation (BSA/FRU, BSA/MGO, and ARG/MGO models) and antioxidant (FRAP, ORAC, and DPPH) properties, as well as the ability to inhibit LDL oxidation and hepatic tissue peroxidation were evaluated. The inhibition of enzyme activity was also analyzed (α-amylase, α-glycosidase, acetylcholinesterase, and butyrylcholinesterase). We also evaluated the antimicrobial and cytotoxicity against RAW 264.7 macrophages. The main compounds present in the most bioactive fractions were elucidated through ESI FT-ICR MS and HPLC-ESI-MS/MS analysis. In the assessment of antioxidant capacity (FRAP, ORAC, and DPPH), the EAF and BF fractions exhibited notable results, and as they are the phenolic compounds richest fractions, they also inhibited LDL oxidation, protected the hepatic tissue from peroxidation and inhibited α-amylase activity. Regarding glycation models, the EE, EAF, BF, and HMF fractions demonstrated substantial activity in the BSA/FRU model. However, BF was the only fraction that presented non-cytotoxic activity in RAW 264.7 macrophages at all tested concentrations. In conclusion, this study provides valuable insights into the antioxidant, antiglycation, and enzymatic inhibition capacities of the ethanolic extract and organic fractions of Centella asiatica. The findings suggest that further in vivo studies, particularly focusing on the butanol fraction (BF), may be promising routes for future research and potential therapeutic applications.

Bioactive compounds from the leaves of Maytenus ilicifolia Mart. ex Reissek: Inhibition of LDL oxidation, glycation, lipid peroxidation, target enzymes, and microbial growth

ETHNOPHARMACOLOGICAL RELEVANCE

Maytenus ilicifolia Mart. ex Reissek, a medicinal plant used for treating gastritis, ulcers, and gastric disorders, possesses therapeutic properties attributed to diverse leaf compounds-terpenoids, alkaloids, flavonoids, phenols, and tannins, reflecting the ethnopharmacological knowledge of traditional users.

AIMS OF THE STUDY

We aimed to assess the antioxidant and antiglycant capacities of Maytenus ilicifolia's ethanolic extract and organic fractions, identify bioactive compounds through HPLC-MS/MS analysis, and conduct phytochemical assessments. We also assessed their potential to inhibit digestive and cholinesterase enzymes, mitigate oxidation of human LDL and rat hepatic tissue, and examine their antimicrobial and cytotoxic properties.

MATERIALS AND METHODS

Organic fractions (hexane - HF-Mi, dichloromethane - DMF-Mi, ethyl acetate - EAF-Mi, n-butanol - BF-Mi, and hydromethanolic - HMF-Mi) were obtained via liquid-liquid partitioning. Antioxidant (DPPH, FRAP, ORAC) and antiglycant (BSA/FRU, BSA/MGO, ARG/MGO/LDL/MGO models) capacities were tested. Phytochemical analysis employed HPLC-MS/MS. We also studied the inhibitory effects on α-amylase, acetylcholinesterase, butyrylcholinesterase, human LDL and rat hepatic tissue oxidation, antimicrobial activity, and cytotoxicity against RAW 264.7 macrophages.

RESULTS

HPLC-ESI-MS/MS identified antioxidant compounds such as catechin, quercetin, and kaempferol derivatives. Ethanolic extract (EE-Mi) and organic fractions demonstrated robust antioxidant and antiglycant activity. EAF-Mi and BF-Mi inhibited α-amylase (2.42 μg/mL and 7.95 μg/mL) compared to acarbose (0.144 μg/mL). Most organic fractions exhibited ∼50% inhibition of acetylcholinesterase and butyrylcholinesterase, rivaling galantamine and rivastigmine. EAF-Mi, BF-Mi, and EE-Mi excelled in inhibiting lipid peroxidation. All fractions, except HMF-Mi, effectively countered LDL oxidation, evidenced by the area under the curve. These fractions protected LDL against lipid peroxidation.

CONCLUSION

This study unveils Maytenus ilicifolia's ethanolic extract and organic fractions properties. Through rigorous analysis, we identify bioactive compounds and highlight their antioxidant, antiglycant, enzyme inhibition, and protective properties against oxidative damage. These findings underline its significance in modern pharmacology and its potential applications in healthcare.

An In Vivo Assessment of the Effect of Hexane Extract from Endlicheria paniculata Branches and Its Main Compound, Methyldehydrodieugenol B, on Murine Sponge-Induced Inflammation

The present study aims to explore the anti-inflammatory potential activity of the hexane extract from branches (HEB) of Endlicheria paniculata (Lauraceae) and its main compound, methyldehydrodieugenol B, in the inflammatory response induced by a murine implant sponge model. HPLC-ESI/MS analysis of HEB led to the identification of six chemically related neolignans, with methyldehydrodieugenol B as the main compound. An in silico analysis of the pharmacokinetic parameters of the identified compounds suggested moderate solubility but good absorption and biodistribution in vivo. Thus, the treatment of mice with HEB using in vivo assays indicated that HEB promoted pro-inflammatory, antiangiogenic, and antifibrogenic effects, whereas treatment with methyldehydrodieugenol B caused anti-inflammatory, antifibrogenic, and antiangiogenic effects. The obtained results shown the therapeutic potential of HEB and methyldehydrodieugenol B in the treatment of pathologies associated with inflammation and angiogenesis, including chronic wounds.

Antioxidant compounds of Kielmeyera coriacea Mart. with α-amylase, lipase and advanced glycation end-product inhibitory activities

Chronic hyperglycemia and hyperlipidemia are associated with excessive formation of reactive oxygen species and advanced glycation end-products. The present study aimed to evaluate the potential in vitro antidiabetic properties of Kielmeyera coriacea inner bark. The main phytochemical compounds were identified by UHPLC-ESI/MSⁿ and the ethanol extract and its fractions were used to evaluate their antioxidant and anti-glycation capacities, as well as their inhibitory potential against glycoside and lipid hydrolases activities. The polar fractions, especially the n-butanol fraction, had free radical scavenging and quenching properties (ORAC and FRAP values>1800 and 1000 µmol trolox eq/g, respectively, and DPPH IC₅₀<4 µg/mL), and inhibited ROS production (p < 0.01), lipid peroxidation (p < 0.001), glycation (IC₅₀ ~ 10 µg/mL in the BSA-fructose assay; IC₅₀ ~ 200 µg/mL in the BSA-methylglyoxal and arginine-methylglyoxal assays), α-amylase (IC₅₀<0.1 µg/mL) and lipase (IC₅₀<5 µg/mL), with no cytotoxicity. Biomolecules well-known as potent antioxidants were identified for the first time in the inner bark of K. coriacea, such as protocatechuic acid, epicatechin and procyanidins A, B and C. Together, our results support the antioxidant, anti-glycation and glycoside and lipid hydrolases inhibitory properties of the inner bark of K. coriacea, a species found in the Brazilian savanna, which makes it especially useful to combat oxidative stress and hyperglycemia and hyperlipidemia.

Identification of Substances Produced by Cercospora brachiata in Absence of Light and Evaluation of Antibacterial Activity

Cercospora brachiata is a phytopathogenic fungus. To know more about the metabolites produced by this fungus, the objective of this work was to identify, isolate and characterize substances present in extracts of the growth broth and mycelium, using gas chromatography with mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). It was also objective to evaluate the antibacterial activity of the extracts. Among the compounds identified, fatty acids, esters, and steroids can be highlighted. The main compounds identified are 9-hexadecenoic, hexadecenoic, oleic, octadecanoic, lauric, myristic, palmitic, doceno-13-enoic, stearic, linoleic, and nonadecanoic acids present in almost all extracts. For the antibacterial activity, the broth microdilution method was used. The ethyl acetate extract of the mycelium presented inhibitory concentrations (MICs) against the bacterium Actinomyces naeslundii (100 μg mL^-1) and Streptococcus sanguinis (200 μg mL^-1). Finally, two steroids were isolated and identified in the hexane extract of mycelium: ergosta-6,22-dien-3β,5α,8α-triol and brassicasterol.

Evaluation of Gibbilimbol B, Isolated from Piper malacophyllum (Piperaceae), as an Antischistosomal Agent

Infections caused by parasitic worms impose a considerable worldwide health burden. One of the most impactful is schistosomiasis, a disease caused by blood-dwelling of the genus Schistosoma that affects more than 230 million people worldwide. Since praziquantel has also been extensively used to treat schistosomiasis and other parasitic flatworm infections, there is an urgent need to identify novel anthelmintic compounds, mainly from natural sources. In this study, the hexane extract from roots of Piper malacophyllum (Piperaceae) showed to be mainly composed for gibbilimbol B by HPLC/ESI-HRMS. Based on this result, this compound was isolated by chromatographic steps and its structure was confirmed by NMR. In vitro bioassays showed that gibbilimbol B was more active than praziquantel against larval stage of S. mansoni, with effective concentrations of 50 % (EC₅₀ ) and 90 % (EC₉₀ ) values of 2.6 and 3.4 μM, respectively. Importantly, gibbilimbol B showed no cytotoxicity to mammalian cells at a concentration 190 times greater than the antiparasitic effect, giving support for the anthelmintic potential of gibbilimbol B as lead compound for novel antischistosomal agents.

Dehydrodieugenol B and hexane extract from Endlicheria paniculata regulate inflammation, angiogenesis, and collagen deposition induced by a murine sponge model

The present study reports the evaluation of hexane extract from Endlicheria paniculata and its main metabolite dehydrodieugenol B in the inflammatory response induced by a murine implant sponge model. As a result, a reduction in the inflammatory markers (myeloperoxidase and N-acetyl-β-D-glucosaminidase) and number of mast cells were observed in comparison to the control group. All doses were also able to reduce angiogenic parameters evaluated in fibrovascular tissue. In implants treated with dehydrodieugenol B a reduction in total collagen deposition and types I and III collagen fibers were observed, while an increased in total collagen deposition and types I and III collagen fibers were observed in the treatment with hexane extract. Docking studies into cyclooxygenase-2 active site revealed that the dehydrodieugenol B had binding modes and energies comparable with celecoxib, diclofenac and ibuprofen. Therefore, dehydrodieugenol B was able to alter key components of chronic inflammation, resulting in a reduced inflammatory response and also presenting antifibrogenic and antiangiogenic effects. However, treatment with hexane extract resulted in a reduced inflammatory response with antiangiogenic effects, but caused fibrogenic effects.

Antioxidant compounds from Banisteriopsis argyrophylla leaves as α-amylase, α-glucosidase, lipase, and glycation inhibitors

Banisteriopsis argyrophylla belongs to the Malpighiaceae family, which is a species from Cerrado, also known as "cipó-prata" or "cipó-folha-de-prata." Several species of this family present biological potential. This work reports the chemical identification of the ethanol extract (EE) and its fractions from B. argyrophylla leaves and shows the analysis of the antioxidant activity and inhibitory effects on activities of α-amylase, α-glucosidase and lipase, and non-enzymatic glycation. The ethyl acetate fraction (EAF) and n-butanol fraction (BF) showed antioxidant activity, with IC₅₀ values of 4.1 ± 0.1 and 4.8 ± 0.1 μg mL^-1, respectively, by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and IC₅₀ values of 6046.3 ± 174.2 and 6264.2 ± 32.2 µmol Trolox eq g^-1 by the oxygen radical absorbance capacity (ORAC) method. Furthermore, the DPPH method with these fractions presented electroactive species with antioxidant potential, as shown by the differential pulse voltammetry (DPV) method. The inhibitory effects of the EAF and BF were demonstrated by the following results: IC₅₀ of 5.1 ± 0.3 and 2.5 ± 0.2 μg mL^-1 for α-amylase, IC₅₀ of 1093.5 ± 26.0 and 1250.8 ± 21.9 μg mL^-1 for α-glucosidase, IC₅₀ of 8.3 ± 4.1 and 4.4 ± 1.0 μg mL^-1 for lipase, and IC₅₀ of 1.3 ± 0.1 and 0.9 ± 0.1 μg mL^-1 for glycation. Some bioactive compounds were identified by (-)-ESI-MS/MS, such as catechin, procyanidins, glycosylated flavonoids, kaempferol, and megastigmane glucosides. The antidiabetic activity of B.argyrophylla has been reported for the first time.

Chemical Constituents and Antileishmanial and Antibacterial Activities of Essential Oils from Scheelea phalerata

Scheelea phalerata Mart. ex Spreng (Arecaceae) is a palm tree found in the Brazilian cerrado. There are no topics related to volatile oils from S. phalerata leaves in the literature. This work determines its chemical composition and evaluates the biological activity under two different seasonal conditions (dry and rainy seasons). The dry essential oil yield was 0.034 ± 0.001% and the rainy essential oil yield was 0.011 ± 0.003%. Both essential oils presented different qualitative and quantitative compositions (99.4 and 98.5%). The main constituents of the dry essential oil were phytol (36.7%), nonadecane (9.7%), linolenic acid (9.1%), (Z)-hex-3-en-1-ol (4.2%), and squalene (4.0%). The main constituents of the rainy essential oil were phytol (26.1%), palmitic acid (18.7%), hexan-1-ol (15.6%), (Z)-hex-3-en-1-ol (9.7%), and oleic acid (4.0%). The antileishmanial activity against promastigotes of Leishmania amazonensis was observed only for the rainy season essential oil (IC₅₀ value of 165.05 ± 33.26 μg mL^-1). A molecular docking study showed that alcohols exert a paramount efficacy and that the action of some essential oil compounds may be similar to that of amphotericin B. Still, only the essential oil from the dry season showed moderate antibacterial activity against S. sanguinis (MICs 200-400 μg mL^-1). The cytotoxicity against Vero cells was identical (>512) for both essential oils. The novel data here for both chemical characterization and biological activity, in particular, evidence that the action of these compounds is similar to that of amphotericin B, provide valuable information to the drug-discovery field.

Dose to the interventional radiologist in CTF-guided procedures

The aim of this work was to assess the occupational dose received by an interventional radiologist (IR) during computed tomography fluoroscopy (CTF)-guided procedures; to identify the most exposed areas of the body including the hands and fingers; to suggest recommendations for individual monitoring; and to improve radiation safety of the practice. A total of 53 CTF-guided procedures were studied. Twelve whole-body dosimeters were worn by the IR in each procedure for the assessment of the personal dose equivalent, H_p(10), on the chest, waist, and back, both over and under the lead apron, as well as the personal dose equivalent, H_p(0.07), on both arms, knees, and feet. Special gloves with casings to fit extremity dosimeters were prepared to assess H_p(0.07) to the fingers. The measured chest dose values were higher than those on the waist and back; the dominant hand or the left side was the most exposed. In general, the ring, middle, and index fingers of the dominant hand were the most exposed (maximum in the 36-39 mSv range), while wrist dose was negligible compared to finger doses. Based on the results obtained the following recommendations are suggested: protective devices (lead aprons, thyroid shield, and goggles) should be worn; H_p(10) should be assessed at the chest level both above and below the lead apron; finger doses can be measured on the basis of each middle finger; the arm closer to the beam should be monitored; and finally, a wrist dosimeter will not provide useful information.

Ventilation distribution as a contributor to the functional exercise capacity in patients with systemic sclerosis-associated interstitial lung disease without pulmonary hypertension

Phenotypic differences have been described between patients with systemic sclerosis (SSc)-associated interstitial lung disease (ILD) and SSc-associated pulmonary hypertension, including performance differences in the 6-min walk test (6MWT). Moreover, the correlations between the 6MWT and traditional pulmonary function tests (PFTs) are weak, indicating the need to search for new parameters that explain exercise performance. Thus, our objective was to evaluate the impact of ventilation distribution heterogeneity assessed by the nitrogen single-breath washout (N2SBW) test and peripheral muscle dysfunction on the exercise capacity in patients with SSc-ILD and limited involvement of the pulmonary parenchyma. In this cross-sectional study, 20 women with SSc-ILD and 20 matched controls underwent PFTs (including spirometry, diffusing capacity for carbon monoxide (DLco), and the N2SBW test) and performed the 6MWT and knee isometric dynamometry. The 6-min walking distance (6MWD, % predicted) was strongly correlated with the phase III slope of the single-breath nitrogen washout (phase III slopeN2SBW) (r=-0.753, P<0.0001) and reasonably correlated with the forced vital capacity (FVC) (r=0.466, P=0.008) and DLco (r=0.398, P=0.011). The peripheral oxygen saturation (SpO2) during exercise was not significantly correlated with any of the pulmonary or muscle function parameters. The phase III slopeN2SBW was the only predictive variable for the 6MWD, whereas quadriceps strength and FVC/DLco were predictive variables for SpO2. Ventilation distribution heterogeneity is one factor that contributes to a lower 6MWD in SSc-ILD patients. In addition, muscle dysfunction and abnormal lung diffusion at least partly explain the decreased SpO2 of these patients.

Antifungal and cytotoxicity activities of Banisteriopsis argyrophylla leaves

OBJECTIVES

This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites.

METHODS

The EtOAc fraction (EAF) obtained from the ethanolic extract of B. argyrophylla leaves showed better antifungal potential against Candida spp. In this fraction, ten flavonoids have been identified by UHPLC-ESI-MSⁿ . Then, EAF was submitted to column chromatography to give four new fractions (A1-A4). The cytotoxicity was determined against Vero cells.

KEY FINDINGS

The EAF showed better antifungal potential against Candida spp. with minimum inhibitory concentrations (MICs) between 31.25 and 93.75 μg/ml. The (-)-catechin (fraction A1) showed a MIC of 2.83 μg/ml against Candida glabrata. Fractions A2, A3 and A4 were rich in quercetins and kaempferols and showed good inhibitory concentrations (5.86-46.87 μg/ml) against C. albicans, C. glabrata and C. tropicalis.

CONCLUSIONS

The EtOH extract, fractions and the isolated (-)-catechin showed lower toxicity to Vero cells than cisplatin, used as a positive control. Thus, the leaves of B. argyrophylla are a promising source of antifungal agents.

Phytochemical characterization of the Vochysia rufa (Vochysiaceae) extract and its effects on oxidative stress in the pancreata of streptozotocin-induced diabetic rats

Aqueous extract of macerated Vochysia rufa stem bark has been commonly used in the treatment of diabetes. Therefore, we evaluated the antihyperglycemic and antioxidant effects of an extract of V. rufa on the pancreata of streptozotocin (STZ)-induced diabetic rats. Animals received one of the following treatments daily by oral gavage: water (diabetic-control), V. rufa extract (diabetic-V. rufa), or glibenclamide (diabetic-GBD). Total antioxidant capacity; levels of thiobarbituric acid reactive substances, reduced glutathione, and sulfhydryls; and superoxide dismutase, catalase, and glutathione peroxidase (GPx) activities were measured in the pancreas. Biochemical analysis of serum total cholesterol and fractions, triglycerides, creatinine, urea, acid uric, ALP, γ-GT, AST, and ALT was performed, and pancreatic β-cells positive for insulin were evaluated by immunohistochemistry. Rats treated with extract exhibited a decrease in fasting blood glucose compared with levels in diabetic control rats. GPx activity and sulfhydryl levels were significantly lower in diabetic-V. rufa rats compared with those of diabetic-control rats. V. rufa extract acted to normalize the biochemical alterations found in diabetic rats (diabetic-controls), as demonstrated by increases in urea, HDL, ALP, AST, and ALT. Reduction in blood glucose was independent of an increase in insulin. The V. rufa extract was found to be composed of free sugars (inositol, galactose, glucose, mannose, sucrose, arabinose, and ribose) as the main metabolites. Thus, aqueous extract of the stem bark of V. rufa is capable of reducing blood glucose, resulting in an antioxidant effect on the pancreatic tissue of STZ-diabetic rats.

New alkenyl derivative from Piper malacophyllum and analogues: Antiparasitic activity against Trypanosoma cruzi and Leishmania infantum

Alkylphenols isolated from Piper malacophyllum (Piperaceae), gibbilimbols A and B, showed interesting activity against the parasites Trypanosoma cruzi and Leishmania infantum. In continuation to our previous work, a new natural product from the essential oil of the leaves of P. malacophyllum was isolated, the 5-[(3E)-oct-3-en-1-il]-1,3-benzodioxole, and also a new set of five compounds was prepared. The antiparasitic activity of the natural product was evaluated in vitro against these parasites, indicating potential against the promastigote/trypomastigote/amastigote forms (IC₅₀ 32-83 μm) of the parasites and low toxicity (CC₅₀  > 200 μm) to mammalian cells. The results obtained to the synthetic compounds indicated that the new derivatives maintained the promising antiparasitic activity, but the cytotoxicity was considerably lowered. The amine derivative LINS03011 displayed the most potent IC₅₀ values (13.3 and 16.7 μm) against amastigotes of T. cruzi and L. infantum, respectively, indicating comparable activity to the phenolic prototype LINS03003, with threefold decreased (CC₅₀ 73.5 μm) cytotoxicity, leading the selectivity index (SI) towards the parasites up to 24.5. In counterpart, LINS03011 has not shown membrane disruptor activity in SYTOX Green model. In summary, this new set showed the hydroxyl is not essential for the antiparasitic activity, and its substitution could decrease the toxicity to mammalian cells.

Seasonal variation of the chemical composition and antimicrobial and cytotoxic activities of the essential oils from Inga laurina (Sw.) Willd

The seasonal chemical composition of essential oils from Inga laurina was determined by GC/MS. In the stem bark’s essential oil extracted during the dry season, the presence of terpenoids (30.05%) stood out, and phytol (9.76%) was the major compound identified. For the stem bark oil obtained during the rainy season, in addition to terpenoids (26.63%), a large amount of fatty acids (46.84%) were identified, in particular palmitic acid (25.40%). Regarding the leaves’ essential oil obtained in the dry season, esters (42.35%) were the main components. The main ester present was (Z)-hex-3-enyl benzoate (10.15%) and the major compound of this oil was (Z)-hex-3-en-1-ol (14.23%). Terpenoids (33.84%), long-chain alkanes (27.04%) and fatty acids (21.72%) were the main components of the essential oil from leaves in the rainy season. Phytol (33.21%), nonacosane (21.95%) and palmitic acid (15.20%) were the major compounds identified. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method and cytotoxic activity was carried out with Vero cells. The essential oils from the rainy season showed a better inhibition of the bacterial growth with Minimal Inhibitory Concentrations (MIC) values of 25 or 50 µg·mL⁻¹ for aerobic bacteria, and high selectivity against bacteria was observed. The large amount of fatty acids in rainy season oils may be related to the better inhibitory effects observed.

Chemical composition, cytotoxic and antimicrobial activity of essential oils from Cassia bakeriana Craib. against aerobic and anaerobic oral pathogens

The chemical composition of the essential oils from leaves, bark and wood of Cassiabakeriana Craib. was determined by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL⁻¹ for most of the tested bacteria, including Streptococcusmutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC₅₀ of 153 µg·mL⁻¹), while wood oil exhibited the highest toxicity to Vero cells. C.bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C.bakeriana.

Leishmanicidal activity of an alkenylphenol from Piper malacophyllum is related to plasma membrane disruption

Leishmaniasis and Chagas disease are parasitic protozoan infections that affect the poorest population in the world, causing high mortality and morbidity. As a result of highly toxic and long-duration treatments, novel, safe and more efficacious drugs are essential. In this work, the methanol (MeOH) extract from the leaves of Piper malacophyllum (Piperaceae) was fractioned to afford one alkenylphenol, which was characterized as 4-[(3'E)-decenyl]phenol (gibbilimbol B) by spectroscopic methods. Anti-protozoan in vitro assays demonstrated for the first time that Leishmania (L.) infantum chagasi was susceptible to gibbilimbol B, with an in vitro EC(50) of 23 μg/mL against axenic promastigotes and an EC(50) of 22 μg/mL against intracellular amastigotes. Gibbilimbol B was also tested for anti-trypanosomal activity (Trypanosoma cruzi) and showed an EC(50) value of 17 μg/mL against trypomastigotes. To evaluate the cytotoxic parameters, this alkenylphenol was tested in vitro against NCTC cells, showing a CC(50) of 59 μg/mL and absent hemolytic activity at the highest concentration of 75 μg/mL. Using the fluorescent probe SYTOX Green suggested that the alkenylphenol disrupted the Leishmania plasma membrane upon initial incubation. Further drug design studies aiming at derivatives could be a promising tool for the development of new therapeutic agents for leishmaniasis and Chagas disease.

Preliminary assessment of the dose to the interventional radiologist in fluoro-CT-guided procedures

A preliminary assessment of the occupational dose to the intervention radiologist received in fluoroscopy computerised tomography (CT) used to guide the collection of lung and bone biopsies is presented. The main aim of this work was to evaluate the capability of the reading system as well as of the available whole-body (WB) and extremity dosemeters used in routine monthly monitoring periods to measure per procedure dose values. The intervention radiologist was allocated 10 WB detectors (LiF: Mg, Ti, TLD-100) placed at chest and abdomen levels above and below the lead apron, and at both right and left arms, knees and feet. A special glove was developed with casings for the insertion of 11 extremity detectors (LiF:Mg, Cu, P, TLD-100H) for the identification of the most highly exposed fingers. The H(p)(10) dose values received above the lead apron (ranged 0.20-0.02 mSv) depend mainly on the duration of the examination and on the placement of physician relative to the beam, while values below the apron are relatively low. The left arm seems to receive a higher dose value. H(p)(0.07) values to the hand (ranged 36.30-0.06 mSv) show that the index, middle and ring fingers are the most highly exposed. In this study, the wrist dose was negligible compared with the finger dose. These results are preliminary and further studies are needed to better characterise the dose assessment in CT fluoroscopy.

Development and validation of a micellar electrokinetic chromatography method for quantitative determination of butenolides in Piper malacophyllum (C. Presl) C. DC

INTRODUCTION

A large number of natural and synthetic compounds having butenolides as a core unit have been described and many of them display a wide range of biological activities. Butenolides from P. malacophyllum have presented potential antifungal activities but no specific, fast, and precise method has been developed for their determination.

OBJECTIVE

To develop a methodology based on micellar electrokinetic chromatography to determine butenolides in Piper species.

METHODOLOGY

The extracts were analysed in an uncoated fused-silica capillaries and for the micellar system 20 mmol/L SDS, 20% (v/v) acetonitrile (ACN) and 10 mmol/L STB aqueous buffer at pH 9.2 were used. The method was validated for precision, linearity, limit of detection (LOD) and limit of quantitation (LOQ) and the standard deviations were determined from the standard errors estimated by the regression line.

RESULTS

A micellar electrokinetic chromatography (MEKC) method for determination of butenolides in extracts gave full resolution for 1 and 2. The analytical curve in the range 10.0-50.0 µg/mL (r(2) = 0.999) provided LOD and LOQ for 1 and 2 of 2.1/6.3 and 1.1/3.5 µg/mL, respectively. The RSD for migration times were 0.12 and 1.0% for peak area ratios with 100.0 ± 1.4% of recovery.

CONCLUSIONS

A novel high-performance MEKC method developed for the analysis of butenolides 1 and 2 in leaf extracts of P. malacophyllum allowed their quantitative determined within an analysis time shorter than 5 min and the results indicated CE to be a feasible analytical technique for the quantitative determination of butenolides in Piper extracts.

Impact of Forpus xanthopterygius (Spix, 1824) (Aves, Psittacidae) on flowers of Handroanthus serratifolius (Vahl.) S. O. Grose (Bignoniaceae)

Handroanthus serratifolius produces flowers during the dry season in the Cerrado biome, and it may be an important food source to some bird species. For Psittacidae species, like Forpus xanthopterygius, flowers are important in their diet. This study intended to characterize the behavior of F.xanthopterygius and evaluate the damage to the flowering and in the reproduction of H. serratifolius. Four individuals of H. serratifolius were observed for 60 hours to register size of groups, the time and duration of visit, and the number of flowers predated by F.xanthopterygius. The groups that visited the plants had between 2 and 12 individuals. The mean time of visits was 60.31 minutes (+/-22.29). The size of groups was correlated to number of flowers predated and was influenced by number of flowers offered. During the flowering, each H. serratifolius individual loses approximately 1,052 flowers per week.

Photon track evolution

Given the time scale of biological, biochemical, biophysical and physical effects in a radiation exposure of living tissue, the first physical stage can be considered to be independent of time. All the physical interactions caused by the incident photons happen at the same starting time. From this point of view it would seem that the evolution of photon tracks is not a relevant topic for analysis; however, if the photon track is considered as a sequence of several interactions, there are several steps until the total degradation of the energy of the primary photon. We can characterise the photon track structure by the probability p(E,j), that is, the probability that a photon with energy E suffers j secondary interactions. The aim of this work is to analyse the photon track structure by considering j as a step of the photon track evolution towards the total degradation of the photon energy. Low energy photons (<150 keV) are considered, with water phantoms and half-extended geometry. The photon track evolution concept is presented and compared with the energy deposition along the track and also with the spatial distribution of the several steps in the photon track.

Comparison of deterministic and Monte Carlo methods in shielding design

In shielding calculation, deterministic methods have some advantages and also some disadvantages relative to other kind of codes, such as Monte Carlo. The main advantage is the short computer time needed to find solutions while the disadvantages are related to the often-used build-up factor that is extrapolated from high to low energies or with unknown geometrical conditions, which can lead to significant errors in shielding results. The aim of this work is to investigate how good are some deterministic methods to calculating low-energy shielding, using attenuation coefficients and build-up factor corrections. Commercial software MicroShield 5.05 has been used as the deterministic code while MCNP has been used as the Monte Carlo code. Point and cylindrical sources with slab shield have been defined allowing comparison between the capability of both Monte Carlo and deterministic methods in a day-by-day shielding calculation using sensitivity analysis of significant parameters, such as energy and geometrical conditions.

[Sport as integration factor of the physically handicapped in our society]

The objective of this study was to make use of sports as a rehabilitation method, as well as to assess the physical, psychological, and social aspects of those present some physical handicap, particularly those who have some kind of chronic disease and are no longer taking part in any rehabilitation program. Thirty handicapped people were evaluated: fifteen started with basketball and fifteen with swimming, according either to the specific preference of each one of them or to the degree and kind of physical impairment. They were submmited to the following evaluations: clinical examination, physiotherapy assessment, social interview and use of the Rivermead Social Scale, functional classification of the sport, use of the Barthel and Rivermead Functional Scales, and the psychological profile test (POMS). After two years, no relevant change in the moving evolution of the athletes were reported. Concerning the POMS psychological test, both basketball and swimming groups presented with high vigor and low depression levels. Considering the social aspects, both groups presented substantial improvement, specially regarding their relationship to one person or more people and also in the everyday activities (be it social, leisure, or domestic), thus leading them to better social integration. This essay shows that sport can bring people who are physically impaired a better social integration and physical conditions.

[Blood pressure in school children and adolescents - The Belo Horizonte study]

OBJECTIVE: To investigate epidemiological aspects of blood pressure (BP) levels, and the prevalence of arterial hypertension in a representative sample of the whole elementary and high school population of the city of Belo Horizonte (state of Minas Gerais, southeastern Brazil). To describe the blood pressure levels found and the prevalence of BP levels above the 90th and 95th percentiles in the first and second measurements. To evaluate prevalence using four different normality references separately to assess the impact of choice of reference. To study the frequency at which the studentś blood pressure has been evaluated.METHODS: In an observational cross-sectional epidemiological study, we studied a sample of 1005 students, aged 6 to 18 year, randomized from an universe of 486,166 students from the 521 public and private elementary and high schools in the city. Each student was evaluated by means of a personal interview, anthropometric measurements, and two blood pressure measurements in a single visit and at a 10-minute interval.RESULTS: The systolic and diastolic blood pressure levels, by age and gender, were slightly lower than those described by the Task Force Report (1987) and by Rosner et al. (1993). The prevalence of BP levels (systolic or diastolic) over the 95th percentile were, according to the reference used: 8.7% - Task Force Report (1987); 5.5% - Rosner et al. (1993); 6.5% - Update on the Task Force Report (1996); and 9.8% - the 95th percentile from our own study. In the second measurement these prevalence rates dropped to 4.9%; 2.4%; 3.5% and 5.8%, respectively.CONCLUSIONS: We present a detailed description (mean values and standard deviations, and the 90th, 95th and 99th percentiles by age and gender) of the BP levels found in both measurements. Mean values and upper percentiles found in this study are very close to those found in the American references, which validates the current use of these references in Brazil. The prevalence of 9.0% of BP levels above the 90th percentile in two measurements made at random hints at the number of children who should be monitored for hypertension, and reinforces the importance of routine evaluation of blood pressure at every pediatric examination.