Parkia from Cerrado: phytochemical bioprospection, toxicity and in vitro bioactivities of bark and flower extracts

Parkia platycephala is the only species of the genus Parkia that is endemic to the brazilian Cerrado and the tree symbol of the state of Tocantins, but there are still few studies regarding its bioprospecting. In this study, we aimed to investigate the phytochemical composition, toxicity and bioactivities of the bark and flower of Parkia platycephala. Hot sequential extractions (Soxhlet) were performed using methanol and hydroethanolic solution (70%), after degreasing the sample (hexane). The presence of flavonoids, tannins, steroids and alkaloids was detected in the preliminary screening. Trilinolein, (Z)-9-octadecenamide, 3-O-methyl-d-glucose were detected by Gas Chromatography coupled to Mass Spectrometry (GC-MS). In the Liquid Chromatography with Diode Array Detector (LC-PDA) analysis, it was detected exclusively ferulic acid (bark) and ellagic acid (flower). The ethanolic extract of the bark (IC50=10.69 ± 0.35 µgmL-1) has an antioxidant potential (DPPH• radical) higher than that of the rutin standard (IC50=15.85 ± 0.08 µgmL-1). All extracts showed excellent anticholinesterase potential (Ellman), with emphasis on the ethanol extract of the flower (IC50 =5.34 ± 0.12 µgmL-1). Regarding toxicity (Artemia salina), the methanolic extract of the bark and the ethanolic extract of the flower presented high and moderate levels, respectively. Such results limit the concentrations of biological activities in this study, however, the antioxidant and anticholinesterase indices fall short of toxicity. The results demonstrated promising antioxidant and anticholinesterase activities of both the bark and the flower of Parkia platycephala.

Eugenol Improves Follicular Survival and Development During in vitro Culture of Goat Ovarian Tissue

This study evaluated the effects of different concentrations (10, 20, or 40 μM) of eugenol (EUG 10, EUG 20, or EUG 40), ascorbic acid (50 μg/mL; AA) or anethole (300 μg/mL; ANE 300) on the in-vitro survival and development of goat preantral follicles and oxidative stress in the cultured ovarian tissue. Ovarian fragments from five goats were cultured for 1 or 7 days in Alpha Minimum Essential Medium (α-MEM+) supplemented or not with AA, ANE 300, EUG 10, EUG 20 or EUG 40. On day 7 of culture, when compared to MEM, the addition of EUG 40 had increased the rate of follicular development, as observed by a decrease in the proportion of primordial follicles alongside with an increase in the rate of normally developing follicles. Furthermore, EUG 40 significantly increased both follicular and oocyte diameters. Subsequently, ovarian fragments from three goats were cultured for 1 or 7 days in α-MEM+ supplemented or not with AA, ANE 300 or EUG 40. All tested antioxidants, except ANE 300, were able to significantly decrease the levels of reactive oxygen species in the ovarian tissue, but EUG 40 could most efficiently neutralize free radicals. All ovarian tissues cultured in the presence of antioxidants, especially EUG 40, presented a significant decrease in H3K4me3 labeling, indicating a silencing of genes that play a role in the inhibition of follicular activation and apoptosis induction. When compared to cultured control tissues, both EUG 40 and ANE 300 significantly increased the intensity of calreticulin labeling in growing follicles. The mRNA relative expression of ERP29 and KDM3A was significantly increased when the culture medium was supplemented with EUG 40, indicating a response to ER stress experienced during culture. In conclusion, EUG 40 improved in-vitro follicle survival, activation and development and decreased ROS production, ER stress and histone lysine methylation in goat ovarian tissue.

Carvacryl acetate nanoencapsulated with chitosan/chichá gum exhibits reduced toxicity in mice and decreases the fecal egg count of sheep infected with gastrointestinal nematodes

The nanoencapsulation of biocomposites with anthelmintic action has been proposed as an alternative for improving their efficiency. Thus, the current study aimed to evaluate the efficacy of carvacryl acetate nanoencapsulated with biopolymers (nCVA) in the control of sheep gastrointestinal nematodes. CVA was nanoencapsulated with chitosan/chichá gum and characterized in terms of its efficacy of encapsulation (EE), yield and zeta potential. The acute toxicity of nCVA was evaluated in mice. For the fecal egg count reduction test, 40 animals were divided into four groups (n = 10) and orally administered the following treatments: G1, 250 mg kg−1 CVA; G2, 250 mg kg−1 nCVA; G3, chitosan/chichá gum (negative control) and G4, 2.5 mg kg−1 monepantel (positive control). Feces were collected on days 0 and 16 posttreatment to determine the eggs per gram of feces (epg). The EE and yield of nCVA were 72.8 and 57.5%, respectively. The nanoparticles showed a size of 764.5 ± 302.5 nm, and the zeta potential at pH 3.2 was +22.0 mV. nCVA presented a 50% lethal dose (LD50) of 2609 mg kg−1. By 16 days posttreatment, CVA, nCVA and monepantel reduced the epg by 52.9.7, 71.5 and 98.7%, respectively, and the epg of sheep treated with nCVA differed from that of the negative control (P > 0.05) but did not differ from that of sheep treated with CVA. In conclusion, the nanoencapsulation of CVA reduced its toxicity, and nCVA showed anthelmintic activity.

Avaliação da Resistência à Tração e da Variação de Cor do Colágeno Dentinário Biomodificado com Rutina Extraída da Dimorphandra Gardneriana

O objetivo do estudo foi avaliar a resistência à tração e a variação de cor do colágeno dentinário biomodificado com RT. 800g de Dimorphandra gardnerianaforam submetidas a cromatografia para obtenção de extrato, que foi seco a 100°C, obtendo 12,4g de RT. 50 molares (parecer 2.006.679) foram utilizados para confeccionar espécimes em forma de palito, que foram divididos em 10 grupos, de acordo com a concentração da RT (0,04%, 0,08% e 0,125%) e o tempo de aplicação (1, 30 e 60 minutos). Os espécimes foram desmineralizados com ácido fosfórico 10%, imersos em soluções de RT e submetidos a teste de tração. Os dados foram analisados com ANOVA e Student-Nelman-Keul. Nível de significância foi de 5%. Adicionalmente, foi avaliada qualitativamente a cor dos espécimes antes e após a biomdificação. O grupo controle apresentou resistência à tração significativamente menor do que os grupos tratados com RT (p<0,05). Não houve diferença estatística entre os grupos biomodificados com RT, independente da concentração e do tempo (p>0,05). O uso de RT não alterou a cor do colágeno dentinário, independente da concentração e do tempo. Conclui-se que a biomodificação, com RT, aumentou a resistência a tração e não alterou a cor do colágeno dentinário.Palavras-chave: Resistência à Tração. Antioxidantes. Propriedades Físicas. Colágeno.

Anacardic Acid Constituents from Cashew Nut Shell Liquid: NMR Characterization and the Effect of Unsaturation on Its Biological Activities

Anacardic acids are the main constituents of natural cashew nut shell liquid (CNSL), obtained via the extraction of cashew shells with hexane at room temperature. This raw material presents high technological potential due to its various biological properties. The main components of CNSL are the anacardic acids, salicylic acid derivatives presenting a side chain of fifteen carbon atoms with different degrees of unsaturation (monoene-15:1, diene-15:2, and triene-15:3). Each constituent was isolated by column chromatography using silica gel impregnated with silver nitrate. The structures of the compounds were characterized by nuclear magnetic resonance through complete and unequivocal proton and carbon assignments. The effect of the side chain unsaturation was also evaluated in relation to antioxidant, antifungal and anticholinesterase activities, and toxicity against Artemia salina. The triene anacardic acid provided better results in antioxidant activity assessed by the inhibition of the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), higher cytotoxicity against A. salina, and acetylcholinesterase (AChE) inhibition. Thus, increasing the unsaturation of the side chain of anacardic acid increases its action against free radicals, AChE enzyme, and A. salina nauplii. In relation to antifungal activity, an inverse result was obtained, and the linearity of the molecule plays an important role, with monoene being the most active. In conclusion, the changes in structure of anacardic acids, which cause differences in polarity, contribute to the increase or decrease in the biological activity assessed.

Activity of cycloartane-type triterpenes and sterols isolated from Musa paradisiaca fruit peel against Leishmania infantum chagasi

The aim of the study was to evaluate in vitro the antileishmanial activity of triterpenes and sterols isolated from Musa paradisiaca (banana) fruit peel used traditionally to treat leishmaniasis. The compounds were isolated from the ethanolic extract of the peel of the banana fruit by column chromatography. The chemical structure of compounds was determined by (1)H and (13)C - nuclear magnetic resonance spectroscopy. The cytotoxicity was measured in RAW 264.7 cells and LLC-MK2. Leishmanicidal activity against L. infantum chagasi promastigotes was performed by the MTT colorimetric method and activity against amastigotes was assayed in mammalian cells using in situ ELISA method. Five compounds were identified, consisting of three triterpenes: cycloeucalenone, 31-norcyclolaudenone and 24-methylene-cicloartanol and a mixture of two sterols: beta-sitosterol and stigmasterol. With the exception of cycloeucalenone, all compounds showed statistically similar activity against promastigote to pentamidine. While, acting against amastigotes, excluding 31-norcyclolaudenone, other compounds showed activity similar to amphotericin B. All compounds showed low cytotoxicity in mammalian cells.

CONCLUSION

This study partially confirms the use of Musa paradisiaca in folk medicine against leishmaniasis. Further in vivo studies are necessary to evaluate the efficacy.

Gastroprotective effect of Byrsonima sericea DC leaf extract against ethanol-induced gastric injury and its possible mechanisms of action

Byrsonima sericea leaves are extensively used in folk medicine in Brazil against gastric disorders. This study investigated the chemical constituents of B. sericea leaf ethanolic extract (BSLE) and its potential gastroprotective activity, with its possible mechanism of the action using ethanol to induce gastric mucosal damage in mice. The phytochemical analysis was carried out to identify the active constituents present in the extract, and the HPLC analysis was performed for the identification of flavonoids. BSLE at oral doses of 125, 250 and 500 mg/kg markedly attenuated the ethanol-evoked gastric lesions by 53.2, 84.9 and 87.6 %, respectively. The BSLE (250 mg/kg) prevented the depletion of gastric mucus and gastric mucosal nonproteic-sulfhydryl groups, SOD and CAT, as well as the increase in the MDA content promoted by absolute ethanol. Moreover, the effect of BSLE against ethanol damage was found to be significantly reduced in mice pretreated with Capsazepine (i.p.), L-NAME (i.p.) or glibenclamide (i.p.), the respective blockers/inhibitors of TRPV1, NO synthase and K+ATP channel. The phytochemical investigation on BSLE revealed the presence of flavonoids rutin, isoquercitrin, kaempferol 3-O-rutinoside and quercetin, which are compounds well known for their antioxidant and gastroprotective properties. These results suggest that BSLE affords gastroprotection through multiple mechanisms, which may be helpful in the treatment of pathologies associated with gastric dysfunctions.

Leishmanicidal and cholinesterase inhibiting activities of phenolic compounds of Dimorphandra gardneriana and Platymiscium floribundum, native plants from Caatinga biome

In recent years, the Brazilian Health Ministry and the World Health Organization have supported research into new technologies that may contribute to the surveillance, new treatments, and control of visceral leishmaniasis within the country. In light of this, the aim of this study was to isolate compounds from plants of the Caatinga biome, and to investigate their toxicity against promastigote and amastigote forms of Leishmania infantum chagasi, the main responsible parasite for South American visceral leishmaniasis, and evaluate their ability to inhibit acetylcholinesterase enzyme (AChE). A screen assay using luciferase-expressing promastigote form and an in situ ELISA assay were used to measure the viability of promastigote and amastigote forms, respectively, after exposure to these substances. The MTT colorimetric assay was performed to determine the toxicity of these compounds in murine monocytic RAW 264.7 cell line. All compounds were tested in vitro for their anti-cholinesterase properties. A coumarin, scoparone, was isolated from Platymiscium floribundum stems, and the flavonoids rutin and quercetin were isolated from Dimorphandra gardneriana beans. These compounds were purified using silica gel column chromatography, eluted with organic solvents in mixtures of increasing polarity, and identified by spectral analysis. In the leishmanicidal assays, the compounds showed dose-dependent efficacy against the extracellular promastigote forms, with an EC50 for scoporone of 21.4µg/mL, quercetin and rutin 26 and 30.3µg/mL, respectively. The flavonoids presented comparable results to the positive control drug, amphotericin B, against the amastigote forms with EC50 for quercetin and rutin of 10.6 and 43.3µg/mL, respectively. All compounds inhibited AChE with inhibition zones varying from 0.8 to 0.6, indicating a possible mechanism of action for leishmacicidal activity.

Insecticidal activity against Aedes aegypti of m-pentadecadienyl-phenol isolated from Myracrodruon urundeuva seeds

BACKGROUND

Myracrodruon urundeuva Fr. Allemao is a common tree in the Caatinga that has been widely used for various medical purposes. Previous studies showed that the ethanol seed extract of M. urundeuva has potent activity against the larval stage of the dengue vector Aedes aegypti. Given this potential insecticidal activity, bioguided separation steps were performed in order to isolate the active compound(s).

RESULTS

The isolation process resulted in only one active chemical compound, identified by infrared spectroscopy and mass spectrometry as m-pentadecadienyl-phenol. This compound presented potent larvicidal and pupicidal activity (LC50 10.16 and 99.06 µg mL(-1) respectively) and great egg hatching inhibitory activity (IC50 49.79 µg mL(-1)). The mode of action was investigated through observations of behavioural and morphological changes performed in third-instar larvae treated with m-pentadecadienyl-phenol solution after 1, 6, 12, 16 and 20 h of exposure. Some changes were observed as flooding of the tracheal system, alterations in siphonal valves and anal gills and lethargy, probably caused by the strong anticholinesterasic activity reported previously.

CONCLUSION

The compound isolated from M. urundeuva seeds, m-pentadecadienyl-phenol, showed potent activity against immature stages of dengue vector, Ae. aegypti, being considered the main larvicidal principle.

Antifungal activity, toxicity and chemical composition of the essential oil of Coriandrum sativum L. fruits

The aims of this study were to test the antifungal activity, toxicity and chemical composition of essential oil from C. sativum L. fruits. The essential oil, obtained by hydro-distillation, was analyzed by gas chromatography/mass spectroscopy. Linalool was the main constituent (58.22%). The oil was considered bioactive, showing an LC₅₀ value of 23 μg/mL in the Artemia salina lethality test. The antifungal activity was evaluated against Microsporum canis and Candida spp. by the agar-well diffusion method and the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were established by the broth microdilution method. The essential oil induced growth inhibition zones of 28 ± 5.42 and 9.25 ± 0.5 for M. canis and Candida spp. respectively. The MICs and MFCs for M. canis strains ranged from 78 to 620 and 150 to 1,250 μg/mL, and the MICs and MFCs for Candida spp strains ranged from 310 to 620 and 620 to 1,250 μg/mL, respectively. C. sativum essential oil is active in vitro against M. canis and Candida spp. demonstrating good antifungal activity.

Toxicity of Brazilian plant seed extracts to two strains of Aedes aegypti (Diptera: Culicidae) and nontarget animals

Seed ethanolic extracts of 21 Brazilian plants were evaluated for ovicidal, larvicidal, and pupicidal activities against insecticide-susceptible (SS) and field-collected (FC) strains of Aedes aegypti (L.) (Diptera: Culicidae), as well as for their effects on nontarget organisms. Myracrodruon urundeuva Fr. Allemao extract was highly toxic to both mosquito strains. Schinopsis brasiliensis Engler extract showed low toxicity and was 38-68 times less toxic to Ae. aegypti larvae than was M. urundeuva extract. The pupicidal activity (LC50) of 14 plant seed extracts ranged between 9 and 433/g/ml, and toxicities were comparable to both mosquito strains. Piptadenia moniliformis Benth. and Luetzelburgia auriculata (Allemao) Ducke extracts showed the highest activities against pupae of FC and SS strains. None of the extracts showed 100% ovicidal activity. In addition, the active extracts did not show high acute toxicity to mice (LD50 > 1.5 g/kg), except that of Enterolobium contortisiliquum (Vell.) Morong. Most of the active extracts exhibited low toxicity against brine shrimp (Artemia sp.) nauplii. The extracts of M. urundeuva, P. moniliformis, and L. auriculata are promising sources of recognized classes of insecticidal compounds with good selectivity against immature stages of Ae. aegypti.

Larvicidal activity of Tagetes erecta against Aedes aegypti

The aim of this study was to evaluate the activity of essential oil from Tagetes erecta against 3rd instars of Aedes aegypti and to determine the amounts of larvicidal thiophenes in all plant tissues. The oil obtained by steam distillation and analyzed by gas chromatography/mass spectrometry showed 14 compounds. The main compounds were piperitone (45.72%), D-limonene (9.67%), and piperitenone (5.89%). The essential oil was active against larvae of Ae. aegypti, with LC50 of 79.78 microg/ml and LC90 of 100.84 microg/ml. The larvicidal thiophene contents were higher in the roots and flowers as demonstrated by high-performance liquid chromatography analysis. Thus, T. erecta constitutes a good source of varied compounds showing larvicidal activity against Ae. aegypti.

Water extracts of Brazilian leguminous seeds as rich sources of larvicidal compounds against Aedes aegypti L

This study assessed the toxicity of seed water extracts of 15 leguminous species upon Aedes aegypti larvae. A partial chemical and biochemical characterization of water extracts, as well as the assessment of their acute toxicity in mice, were performed. The extracts of Amburana cearensis, Anadenanthera macrocarpa, Dioclea megacarpa, Enterolobium contortisiliquum and Piptadenia moniliformis caused 100% of mortalit y after 1 to 3 h of exposure. They showed LC50 and LC90 values ranging from 0.43 ± 0.01 to 9.06 ± 0.12 mg/mL and from 0.71 ± 0.02 to 13.03 ± 0.15 mg/mL, respectively. Among the secondary metabolite constituents, the seed water extracts showed tannins, phenols, flavones, favonols, xanthones, saponins and alkaloids. The extracts also showed high soluble proteins content (0.98 to 7.71 mg/mL), lectin (32 to 256 HU/mL) and trypsin inhibitory activity (3.64 = 0.43 to 26.19 = 0.05 gIT/kg of flour) The electrophoretic profiles showed a great diversity of protein bands, many of which already described as insecticide proteins. The extracts showed low toxicity to mice (LD50 > 0.15 = 0.01 g/kg body weight), but despite these promising results, further studies are necessary to understand the toxicity of these extracts and their constituentsfrom primary and secondary metabolism upon Ae. aegypti.

Variation of ursolic acid content in eight Ocimum species from northeastern Brazil

Ursolic acid is a very important compound due to its biological potential as an anti-inflammatory, trypanocidal, antirheumatic, antiviral, antioxidant and antitumoral agent. This study presents the HPLC analysis of ursolic acid (UA) content in eight different Ocimum species: O. americanum L., O. basilicum L, O. basilicum var purpurascens Benth, O. basilicum var. minimum L, O. gratissimum L, O. micranthum Willd, O. selloi Benth. and O. tenuiflorum L. grown in Northeastern Brazil. In these Ocimum species, UA was detected in different yields, with O. tenuiflorum showing the highest content (2.02%). This yield is very significant when compared with other sources of UA.

Anthelmintic acetogenin from Annona squamosa L. Seeds

Annona squamosa seeds extracts showed anthelmintic activity against Haemonchus contortus, the main nematode of sheep and goat in Northeastern Brazil. A compound 1 was isolated from ethyl acetate extract and inhibited the egg hatching of H. contortus at 25 mg ml(-1). The structure of 1 was determined as a C37 trihydroxy adjacent bistetrahydrofuran acetogenin based on spectroscopic analysis.

Anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils

Because of the development of anthelmintic resistant populations, the search for new drugs is essential to maintain the productivity of small ruminants. The aim of this study was to evaluate the anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils and their major constituents, anethole and thymol. The effects of these oils and their constituents were determined by in vitro assays with the eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus. The two essential oils were evaluated on intestinal nematodes of mice at 800 mg kg(-1) dose. In the last experiment, the mice were treated with larger doses of L. sidoides, 1200 and 1600 mg kg(-1). The essential oils and their constituents prevented more than 98% of the H. contortus eggs from hatching at a concentration of 1.25 mg ml(-1) and inhibited more than 90% of H. contortus larval development at a concentration of 10 mg ml(-1). At a concentration of 800 mg kg(-1), the two essential oils were 46.3% and 11.64% effective against Syphacia obvelata and Aspiculuris tetraptera. At 1200 and 1600 mg kg(-1), L. sidoides essential oil's efficacy on the mouse worm burden was 57.6% and 68.9%, respectively. The fact that L. sidoides essential oil was almost 70% effective against mouse intestinal nematodes indicates it should be evaluated against gastrointestinal nematodes of sheep and goats.

Chemical composition, toxicological aspects and antifungal activity of essential oil from Lippia sidoides Cham

OBJECTIVES

The aims of this study were to test the essential oil from Lippia sidoides Cham. for antifungal activity, in vitro, against Candida spp. and Microsporum canis, to evaluate its acute and subchronic toxicological effects, in vivo, and to determine its chemical constituents.

METHODS

The antifungal activity, in vitro, was initially evaluated by the agar-well diffusion technique, and the MIC and minimum fungicidal concentration (MFC) were determined by the broth microdilution method. The acute and subchronic toxicological effects were determined in mice and rats, respectively. The chemical composition of the essential oil was determined by gas chromatography coupled to mass spectroscopy.

RESULTS

The essential oil obtained from L. sidoides was effective against all tested strains by the agar-well diffusion method. The MICs of L. sidoides essential oil for strains of M. canis ranged from 4 to 70 mg/L and the MFCs ranged from 9 to 150 mg/L. The MICs for strains of Candida spp. ranged from 620 to 2500 mg/L and the MFCs ranged from 1250 to 5000 mg/L. The main constituents of L. sidoides essential oil were thymol (59.65%), E-caryophyllene (10.60%) and p-cymene (9.08%). The acute administration of the essential oil up to 3 g/kg by the oral route to mice was devoid of overt toxicity. The 30 day oral administration of L. sidoides oil (117.95 mg/kg/day) to rats did not induce any significant histopathological, haematological or serum biochemical alterations.

CONCLUSIONS

The essential oil from L. sidoides may be a promising source in the search for new antifungal drugs due to its efficacy and low toxicity.

Essential oil of croton nepetaefolius and its main constituent, 1,8-cineole, block excitability of rat sciatic nerve in vitro

1. The effects of the essential oil of Croton nepetaefolius (EOCN) and its major constituent, 1,8-cineole, on the compound action potential (CAP) of nerve were investigated. 2. Experiments were performed in sciatic nerves dissected from Wistar rats, mounted in a moist chamber and stimulated at a frequency of 0.2 Hz, with electric pulses of 100 micros duration at 20-40 V. Evoked CAP were displayed on an oscilloscope and recorded on a computer. The CAP control parameters were as follows: peak-to-peak amplitude 8.1 +/- 0.6 mV (n = 15); conduction velocity 83.3 +/- 4.2 m/s (n = 15); chronaxie 58.0 +/- 6.8 msec (n = 6); and rheobase 2.8 +/- 0.1 V (n = 6). 3. Lower concentrations of EOCN (100 and 300 microg/mL) and 1,8-cineole (153 and 307 microg/mL; i.e. 1 and 2 mmol/L, respectively) had no significant effects on CAP control parameters throughout the entire recording period. However, at the end of 180 min exposure of the nerve to the drug, peak-to-peak amplitude was significantly (P < 0.05) reduced to 27.4 +/- 6.7 and 1.7 +/- 0.8% of control values by 500 and 1000 microg/mL EOCN, respectively (n = 6), and to 76.5 +/- 4.4, 70.0 +/- 3.9 and 14.8 +/- 4.1% of control values by 614, 920 and 1227 microg/mL (i.e. 4, 6 and 8 mmol/L) 1,8-cineole, respectively (n = 6). Regarding conduction velocity, at the end of the 180 min exposure period, this parameter was significantly reduced to 85.8 +/- 7.3 and 48.7 +/- 12.3% (n = 6) of control values by 500 and 1000 microg/mL EOCN, respectively, and to 86.4 +/- 4.5 and 76.1 +/- 5.2% (n = 6) by 920 and 1227 microg/mL 1,8-cineole, respectively. Chronaxie and rheobase were significantly increased by the higher concentrations of both EOCN and 1,8-cineole. 4. It is concluded that EOCN and its main constituent 1,8-cineole block nerve excitability in a concentration-dependent manner, an effect that was totally reversible with 1,8-cineole but not with EOCN. This suggests that other constituents of EOCN, in addition to 1,8-cineole, may contribute to the mediation of this effect of EOCN.

Ovicidal and larvicidal activity of Melia azedarach extracts on Haemonchus contortus

Haemonchus contortus is responsible for severe economic losses in sheep and goat breeding in the Northeast of Brazil. However, the effectiveness of control is compromised due to anthelmintic resistance and misuse. In the search for natural anthelmintics, Melia azedarach L., a plant indigenous to India but now distributed throughout Brazil, was selected due to the reported anthelmintic properties of its seeds. The aim of this study was to evaluate the anthelmintic activity of the seed and leaf extracts of the Brazilian adapted plant and investigate the type of organic chemical compounds present in the most active extracts. The ovicidal and larvicidal activity of M. azedarach extracts on H. contortus was evaluated through egg hatching and larval development tests. Hexane and ethanol extracts of seeds and chloroform and ethanol extracts of leaves of M. azedarach were used in the tests. To perform the larval development test, feces of an animal free from parasites were mixed with third instar H. contortus larvae and extracts in several concentrations. The coprocultures were incubated for 7 days at 30 degrees C, then the larvae were recovered and counted. LC50 was calculated by probits using the SPSS 8.0 program. The seed ethanol extract was the most active on eggs (LC50=0.36mgmL(-1)) and the leaf ethanol extract showed the best inhibition of larval development (LC50=9.18mgmL(-1)). Phytochemical analysis of the most active extracts revealed the presence of condensed tannins, triterpenes and alkaloids.

Anthelmintic activity of Azadirachta indica A. Juss against sheep gastrointestinal nematodes

Gastrointestinal nematode control has been performed through use of anthelmintics. However, the development of resistant populations has required research into new alternatives. There are popular reports about anti-parasitic activity of Azadirachta indica in animals and plants. The aim of this study was to evaluate the anthelmintic activity of A. indica after feeding sheep with the dried leaves. In this experiment, 40 sheep were allotted into four treatment groups. Group I received a treatment of A. indica dry leaves mixed in a concentrate at a rate of 0.1 g/kg dose for 3 months. Group II was treated with double the dose of Group I. Group III was treated with closantel (Diantel) at the manufacturer-recommended dose once at the beginning of the study and Group IV was not treated. To compare treatment effects, the following parameters were evaluated: egg count per gram of feces (EPG), worm burden, weight gain and haematocrit. EPG and worm burden results were statistically evaluated using the Kruskal-Wallis test. Haematocrit and live weight gain were submitted to analysis of variance (ANOVA) and the means evaluated by Tukey's test with 95% probability. None of the evaluated parameters of the treatment groups were statistically different when compared to the control group, demonstrating that, with the protocol used, A. indica has no anthelmintic effect.

Larvicidal activity of essential oils from Brazilian Croton species against Aedes aegypti L

Aedes aegypti is the major vector of dengue fever, an endemic disease in Brazil. In an effort to find effective and affordable ways of controlling this mosquito, the larvicidal activities of essential oils from Croton species widely found in northeastern Brazil were analyzed. The essential oils were extracted by steam distillation, and their chemical composition was determined by gas liquid-chromatography coupled with mass spectroscopy. The main components were methyleugenol and alpha-copaene for C. nepetaefolius (LC50 of 84 ppm); alpha-pinene and beta-pinene for C. argyrophyloides (LC50 of 102 ppm); and alpha-pinene, beta-phelandrene, and trans-caryophyllene for C. sonderianus (LC50 of 104 ppm). Croton zenhtneri exhibited higher larvicidal activity with LC50 of 28 ppm, and the main active constituent was identified as anethole, a phenylpropanoid compound.

Synthesis and antioxidant, anti-inflammatory and gastroprotector activities of anethole and related compounds

Some derivatives of trans-anethole [1-methoxy-4-(1-propenyl)-benzene] (1) were synthesized, by introducing hydroxyl groups in the double bond of the propenyl moiety. Two types of reactions were performed: (i) oxymercuration/demercuration that formed two products, the mono-hydroxyl derivative, 1-hydroxy-1-(4-methoxyphenyl)-propane (2) and in lesser extent the dihydroxyl derivative, 1,2-dihydroxy-1-(4-methoxyphenyl)-propane (3) and (ii) epoxidation with m-chloroperbenzoic acid that also led to the formation of two products, the dihydroxyl derivative (3) and the correspondent m-chloro-benzoic acid mono-ester, 1-hydroxy-1(4-methoxyphenyl)-2-m-chlorobenzoyl-propane (4). The structures of these compounds were confirmed mainly by mass, IR, 1H and 13C NMR spectral data. The activity of anethole and hydroxylated derivatives was evaluated using antioxidant, anti-inflammatory and gastroprotector tests. Compounds (2) and (3) were more active antioxidant agents than (1) and (4). In the anti-inflammatory assay, anethole showed lower activity than hydroxylated derivatives. Anethole and in lesser extent its derivatives 2 and 4 showed significant gastroprotector activity. All tested compounds do not alter significantly the total number of white blood cells.

Antinociceptive effects of the essential oil of Alpinia zerumbet on mice

Alpinia zerumbet (Pers.) Burtt. et Smith is an aromatic plant that is distributed widely in the tropical and sub-tropical regions of the world. In Brazil, where A. zerumbet is called "colonia", it is used widely in folk medicine for the treatment of various diseases, including hypertension. In the present study, the antinociceptive effects of the orally administered essential oil of A. zerumbet (EOAz) were evaluated in male Swiss mice (20-25 g each). In the acetic acid-induced writhing test, EOAz (30, 100 and 300 mg/kg body wt.; n = 10, n = 13 and n = 15, respectively) was effective at all doses. In the hot-plate test, EOAz significantly increased the latency at doses of 100 and 300 mg/kg body wt., but not at 30 mg/kg body wt., at all observation times up to the 180th min (n = 10 for each dose). In the formalin test, EOAz significantly reduced paw licking time in the second phase of the test at 100 mg/kg body wt. (n = 10), but decreased it in both phases at 300 mg/kg body wt. (n = 10). At 30 mg/kg body wt., the effect of EOAz did not differ from control values in either phase of the formalin test (n = 10). Pretreatment with naloxone (5 mg/kgbodywt., i.p.) caused a significant reversal of the analgesic effect of 300 mg/kg body wt. EOAz (n = 8) that was complete for the first phase, but only partial for the second phase of the formalin test. The data show that orally administered OEAz promotes a dose-dependent antinociceptive effect, with a mechanism of action which probably involves the participation of opiate receptors.

Neuromuscular effects and acute toxicity of an ethyl acetate extract of Spigelia anthelmia Linn

An ethyl acetate extract of Spigelia anthelmia (EASa), with validated anthelmintic activity, was evaluated for its acute toxicity and general effects in albino Swiss mice and for neuromuscular relaxant activity in the frog sciatic-gastrocnemius and rectus abdominis preparation. The extract induced a dose-related myotonia and muscular paralysis of rapid onset at higher doses. The calculated LD50 after oral and intraperitoneal administration was 345.9 [241.4-484.7] mg/kg and 60.8 [47.4-80] mg/kg, respectively. In broilers, intramuscular injection of EASa-induced spastic paralysis qualitatively similar to that obtained after succinylcholine administration and contrasting to the flaccid paralysis induced by D-tubocurarine. The contraction elicited by direct stimulation of the gastrocnemius was blocked by EASa by 54.3+/-4.7% (IC50 = 21.4 [11.2-35.8] microg/ml) and the twitches evoked by stimulation of the sciatic nerve were blocked by 69.1+/-7.4% (IC50 = 17.9 [4.5-34.23] microg/ml). EASa also blocked acetylcholine-induced contractions in the frog rectus abdominis by 58.6+/-7.4% (IC50 = 7.4 [1.7-15.28] microg/ml) but did not decrease tonic contractions induced by a high-potassium Ringer solution. In summary, the ethyl acetate extract of Spigelia anthelmia induces tonic paralysis in vivo, and decreases amplitudes of twitches and increases tonus of skeletal muscle in vitro.

Ovicidal and larvicidal activity in vitro of Spigelia anthelmia Linn. extracts on Haemonchus contortus

The rapid development of anthelmintic resistance, associated with the high cost of the available anthelmintic drugs, had limited the success of gastrointestinal nematodiasis control in sheep and goats and thus awakened interest in the study of medicinal plants as alternative sources of anthelmintics. Spigelia anthelmia extracts obtained with hexane, chloroform, ethyl acetate or methanol, were tested on Haemonchus contortus eggs and larvae via egg hatch and larval development tests. The extracts were evaluated at five concentrations: 3.1, 6.2, 12.5, 25.0 and 50.0 mg ml(-1). At 50.0 mg ml(-1), the ethyl acetate extract inhibited 100% of the egg hatching and 81.2% of the larval development. In a similar way the methanolic extract inhibited 97.4% of the egg hatching and 84.4% of larval development. These results suggest that utilization of S. anthelmia extracts may be useful in the control of sheep and goats gastrointestinal nematodes.

A clinical trial of the effect of a mouth-rinse prepared with Lippia sidoides Cham essential oil in dogs with mild gingival disease

We evaluated the effect of a mouth-rinse prepared using Lippia sidoides essential oil (EO) in dogs with marginal gingivitis. German Shepherd dogs were distributed in two groups: control (control mouth-rinse) and EO (EO mouth-rinse). Both mouth-rinses were applied on the dogs' teeth every 2 days for 2 weeks. At day 0 and day 15, the scores for plaque-bacteria (P), calculus (C), gingivitis (G) and the inflammatory infiltrate (INF) were evaluated blindly. The results were analyzed by the Wilcoxon signed-rank and Mann-Whitney tests (P</=0.05). P, C, G, and INF did not show any alteration in the control group, while in the EO group there were significant reductions in these scores.

Anthelmintic activity of essential oil of Ocimum gratissimum Linn. and eugenol against Haemonchus contortus

The ovicidal activity of the essential oil of Ocimum gratissimum Linn. (Labideae) and its main component eugenol was evaluated against Haemonchus contortus, gastrointestinal parasite of small ruminants. The oil and eugenol were diluted in Tween 20 (0.5%) at five different concentrations. In the egg hatch test, H. contortus eggs were obtained from feces of goats experimentally infected. At 0.50% concentration, the essential oil and eugenol showed a maximum eclodibility inhibition. These results suggest a possible utilization of the essential oil of O. gratissimum as an aid to the control of gastrointestinal helmintosis of small ruminants.

Antinociceptive effects of the essential oil of Croton nepetaefolius on mice

Croton nepetaefolius Baill., is an aromatic plant native to the northeast of Brazil where it is extensively used in folk medicine as a sedative, orexigen and antispasmodic agent. In the present study the antinociceptive effects of the essential oil of C. nepetaefolius (EOCn), administered orally, were evaluated in male Swiss mice (20-25 g). In the acetic acid-induced writhing test, EOCn (100 and 300 mg/kg; N = 14 and N = 12, respectively) was effective at the highest dose. In the hot-plate test, EOCn at 30 and 300 mg/kg, but not at 3 mg/kg, significantly increased the latency at all observation times up to the 180th min (N = 12 for each dose). In the formalin test, EOCn significantly reduced paw licking in the second phase of the test at 100 mg/kg (N = 12), but decreased it in both phases at 300 mg/kg (N = 12). At 30 mg/kg, the effect of EOCn did not differ from control values in either phase of the formalin test (N = 6). Pretreatment with naloxone (5 mg/kg, ip) significantly reversed the analgesic effect of morphine (5 mg/kg, sc) on both phases, but not that of EOCn at 300 mg/kg (N = 6) on both phases of the formalin test. The data show that orally administered EOCn promotes a dose-dependent antinociceptive effect whose mechanisms remain to be elucidated.

Antinociceptive effects of the essential oil of Croton zehntneri in mice

Croton zehntneri is an aromatic plant native to Northeastern Brazil, where it is often used in folk medicine. In the present study the antinociceptive effects of the essential oil of Croton zehntneri (EOCz) were evaluated in mice. EOCz administered orally at doses of 100 and 300 mg/kg reduced paw licking time in the second phase of the formalin test from the control value of 41.61 +/- 8.62 to 12.01 +/- 7.97 and 6.57 +/- 3.42 s, respectively. During the first phase of the formalin test only 300 mg/kg induced a significant alteration (from 58.2 +/- 7.02, control, to 28.7 +/- 4.73 s). The number of contortions in response to intraperitoneal injections of acetic acid did not differ significantly between controls (80.6 +/- 9.01) and experimental (300 mg/kg body weight) animals (89.1 +/- 9.53% of the control numbers; P > or =0.05, Student t-test). In the hot-plate test, EOCz at doses > or =100 mg/kg significantly increased the latency time with respect to controls (11.2 +/- 0.80). At 100 and 300 mg/kg this increase persisted for 180 and 240 min, respectively. The data show that EOCz is effective as an antinociceptive agent.

Misoprostol and illegal abortion in Fortaleza, Brazil

Misoprostol, a prostaglandin E1 analogue indicated for ulcer treatment, has been widely used as an abortifacient by women in Brazil, where abortion is legal only in cases of rape or incest, or to save the woman's life. Because misoprostol is an inefficient abortifacient, many women who use it have incomplete abortions and need uterine evacuation. We reviewed the records of women admitted to the main obstetric hospital of Fortaleza, capital of Ceará state, Brazil, between January, 1990, and July, 1992, for uterine evacuation after induced abortion. The number of incomplete abortions induced by misoprostol increased substantially during the first half of 1990, and declined thereafter. Of the 593 cases in 1991, 75% were related to misoprostol, 10% to the use of other specified drugs, and 6% to unspecified drugs. For the remaining 9% the procedure used was not recorded; these included 3% in whom abortion had been induced by a clandestine abortionist. The number of uterine evacuations per month fell from 89 in August, 1990, to 62 in July, 1991, when sales of misoprostol in Ceará state were suspended. The fall continued after the sale of misoprostol ceased, to about 20 cases in December, 1991; numbers remained around this level until June, 1992, sustained by clandestine sales. The lack of access to contraception is the main reason for the large numbers of unplanned pregnancies and is a major public health issue for Brazilian women. The prohibition of abortion creates a void in which misuse of medicines is one extra complication, mainly because of the poor control of drug marketing.